Graudillard9433
The neutral atoms coupled to a highly excited Rydberg state on a two-dimensional triangular lattice are investigated by employing the density matrix renormalization group technique in the matrix product state form. The full ground-state phase diagram as a function of blockade radius and the detuning of the exciting laser is determined by the behavior of entanglement entropy. We find several quantum phases including stripe-ordered and symmetry-breaking density-wave-ordered phases featured with regular excitation patterns of different excitation densities ρ = 1/3, 1/4, and 1/7. In addition, a ρ = 2/3 ordered phase and an interesting "order-by-disorder" phase, which has been prepared experimentally, are also observed in this work. Our work provides an exploration of the possible quantum phases that can occur in a triangularly arrayed Rydberg system, and thus could be a faithful theoretical guide for further experimental research.We provide the first, to the best of our knowledge, experimental demonstration of a geometric phase generated in association with closed Poincaré sphere trajectories comprising geodesic arcs that do not start, end, or necessarily even include, the north and south poles that represent pure Laguerre-Gaussian modes. Arbitrarily tilted (elliptical) single vortex states are prepared with a spatial light modulator, and Poincaré sphere circuits are driven by beam transit through a series of π-converters and Dove prisms.A new, to the best of our knowledge, type of acousto-optic Q-switch was developed using slow shear acoustic mode in potassium yttrium tungstate (KYW) crystal. Two Q-switch configurations were created one for vertical and one for horizontal light polarization, both providing over 50% diffraction efficiency at a wavelength of 2.1 μm and an RF driving power below 8 W. The laser-induced damage threshold of the KYW crystal was found to equal 650 MW/cm2. Operation of a nanosecond periodically pulsed HoYAG laser emitting 15 mJ pulses at 2.1 μm with the KYW Q-switch is reported.Based on the electrically controlled birefringence effect in liquid crystal materials, an effective method for spatially separating azimuthally and radially polarized beams from non-polarized incident light waves is proposed. The radially polarized beam was highly converged by using a microhole-patterned electrode and a planar photo-alignment layer to shape the initial liquid-crystal radial alignment and a gradient refractive index distribution with central axial symmetry after applying a voltage signal. Due to the intrinsic polarization sensitivity of nematic liquid-crystal materials, the shaped gradient refractive index only applies to extraordinary light waves, which then converge into a spot. Thus, the azimuthally and radially polarized beams are effectively separated. The proposed method demonstrates some advantages, such as low cost, miniaturization, and easy fabrication and integration with other functional devices. Thanks to the wideband electrically controlled birefringence of liquid-crystal materials, this light-wave manipulation to spatially separate azimuthally and radially polarized beams can also be performed over a wide wavelength range.Phase-matched nonlinear wave mixing, e.g., second-harmonic generation (SHG), is crucial for frequency conversion for integrated photonics and applications, where phase matching wavelength tunability in a wide manner is important. Here, we propose and demonstrate a novel design of angle-cut ridge waveguides for SHG on the lithium niobate-on-insulator (LNOI) platform via type-I birefringent phase matching (BPM). The unique strong birefringence of LN is used to achieve flexible temperature tuning. We experimentally demonstrate a normalized BPM conversion efficiency of 2.7%W-1cm-2 in an angle-cut LN ridge waveguide with a thermo tuning slope of 1.06 nm/K at the telecommunication C band. The approach effectively overcomes the spatial walk-off effect and avoids the need for periodic domain engineering. Furthermore, the angle-cut ridge waveguide scheme can be universally extended to other on-chip birefringent platforms where domain engineering is difficult or immature. The approach may open up an avenue for tunable nonlinear frequency conversion on integrated photonics for broad applications.A silicon on-chip spectral shaper based on a Sagnac loop incorporating a chirped multi-mode waveguide Bragg grating (WBG) for linearly chirped microwave waveform generation is fabricated and demonstrated. The transmission spectrum of the spectral shaper displays low insertion loss characteristic due to the application of edge coupling taper and multi-mode waveguide based grating. An up-chirped microwave waveform with bandwidth as large as 44 GHz is generated by mapping the spectrum profile of the spectral shaper to the temporal domain through a dispersion fiber. The instantaneous frequency of the generated signal shows good linearity benefiting from the weak modulation strength in the multi-mode WBG. The low insertion loss performance as well as the low dispersion value required in our design presents feasibility in further integration with on-chip dispersion.Implantable silicon neural probes with integrated nanophotonic waveguides can deliver patterned dynamic illumination into brain tissue at depth. Here, we introduce neural probes with integrated optical phased arrays and demonstrate optical beam steering in vitro. Beam formation in brain tissue is simulated and characterized. The probes are used for optogenetic stimulation and calcium imaging.Based on the electrically controlled birefringence effect in liquid crystal materials, an effective method for spatially separating azimuthally and radially polarized beams from non-polarized incident light waves is proposed. The radially polarized beam was highly converged by using a microhole-patterned electrode and a planar photo-alignment layer to shape the initial liquid-crystal radial alignment and a gradient refractive index distribution with central axial symmetry after applying a voltage signal. Due to the intrinsic polarization sensitivity of nematic liquid-crystal materials, the shaped gradient refractive index only applies to extraordinary light waves, which then converge into a spot. Thus, the azimuthally and radially polarized beams are effectively separated. The proposed method demonstrates some advantages, such as low cost, miniaturization, and easy fabrication and integration with other functional devices. Thanks to the wideband electrically controlled birefringence of liquid-crystal materials, this light-wave manipulation to spatially separate azimuthally and radially polarized beams can also be performed over a wide wavelength range.Many existing polarization networks reconstruct polarization information based on calculating the angle of polarization (AoP) loss. Yet, the conventional loss calculation method, which is based on a linear difference approach, compromises the reconstruction accuracy and causes additional training time when combined with learning-based methods. In this Letter, we present a new, to the best of our knowledge, method to calculate the AoP loss and apply it in an enhanced color polarization demosaicking network with a "multi-branch" structure, i.e., ePDNet. Experiments are performed to demonstrate the efficacy and superiority of the method, which improves the network convergence speed by three times as well as the output image quality. The new method may find important applications in the field of polarimetric imaging.We address the antireflection (AR) properties of periodic surfaces, or metasurfaces, supporting substrate waves. The work is motivated by recent literature where AR bands formed by substrate-wave propagation are incorrectly attributed to Mie scattering. In contrast, as clearly shown here, substrate-wave generation with corresponding AR signatures is a diffractive effect due to a periodic lattice and is not due to particle scattering as in Mie resonance. Treating both 1D and 2D surfaces, we demonstrate a clear quantitative connection between major AR loci and corresponding total substrate transmittance loci via maps in period versus wavelength. As shown, this holds for fully dispersed, lossy surfaces as well. The results presented here serve to elucidate the physical properties of periodic metasurfaces placed on substrates admitting propagating diffraction orders and may inform the design and implementation of grating-based AR structures.Tunable microwave dispersion is highly desired for a wide field of microwave signal processing. However, a conventional microwave dispersive delay line usually suffers from either a small dispersion value or a narrow operation bandwidth. Here, we experimentally demonstrate the optically magnified dispersion of a microwave signal with a wide and flexible tunable range, based on a bandwidth-scaling microwave photonic system. The obtained microwave dispersion can therefore be magnified from the corresponding optical dispersion with a magnification factor that can be continuously tuned from 10,000 to 85,000. Meanwhile, a proof-of-concept experiment that includes both compression and stretching of chirped microwave pulses is reported. Microwave dispersion from 1.34 ns/GHz to 10.92 ns/GHz can be secured by the corresponding magnification of an optical dispersion value of 16 ps/nm.Optical camera communication (OCC) is a promising technology to be used in future wireless communication systems. In this work, a cluster-based data detection procedure is applied to enhance the performance of an OCC system. A multispectral camera is employed to capture the spectral variations in light-emitting diodes (LEDs) caused by temperature. This strategy's system performance is compared with a system that uses traditional linear methods, such as zero-forcing (ZF) and minimum mean square error (MMSE) equalizers. The findings of this study indicate that an improvement in the bit error rate (BER) can be achieved by applying a clustering approach.Tunable focusing is a desired property in a wide range of optical imaging and sensing technologies but has tended to require bulky components that cannot be integrated on-chip and have slow actuation speeds. Recently, integration of metasurfaces into electrostatic micro-electromechanical system (MEMS) architectures has shown potential to overcome these challenges but has offered limited out-of-plane displacement range while requiring large voltages. We demonstrate for the first time, to the best of our knowledge, a movable metasurface lens actuated by integrated thin-film PZT MEMS, which has the advantage of offering large displacements at low voltages. An out-of-plane displacement of a metasurface in the range of 7.2 μm is demonstrated under a voltage application of 23 V. This is roughly twice the displacement at a quarter of the voltage of state of the art electrostatic out-of-plane actuation of metasurfaces. Using this tunability, we demonstrate a varifocal lens doublet with a focal shift of the order of 250 μm at the wavelength 1.55 μm. The thin-film PZT MEMS-metasurface is a promising platform for miniaturized varifocal components.We propose and investigate an all-solid ytterbium-doped antiresonant fiber (YbARF) design to inherently suppress four-level lasing with >20 dB/m of selective loss and achieve high-efficiency three-level lasing while maintaining near-diffraction-limited operation with an ultra-large mode area of approximately 3630 µm2. The YbARF is designed such that the high-gain wavelengths corresponding to four-level lasing lie in the resonance band characterized by high confinement loss. This enables three-level lasing with high efficiency in a short (0.8-m-long) YbARF, making it a potential candidate for high-peak-power ultrafast lasers at 976 nm. We discuss fiber design considerations and detailed simulation results for three-level lasing performance in the YbARF, which promises >85% lasing efficiency in a single-pass pump configuration. These design concepts can be easily extended to suppress high-gain wavelengths in other rare-earth-doped (e.g., with thulium, erbium, and neodymium) fiber amplifiers or lasers.This paper numerically investigates the evolution of solitons in an optical lattice with gradual longitudinal manipulation. We find that the stationary solutions (with added noise to the amplitude) keep their width, profile, and intensity very well, although the propagation path is continuously changing during the modulated propagation. Discontinuities in the modulation functions cause the scattering of the beam that may end the stable propagation. Our results reveal a method to control the trajectory of solitons by designed variation of the optical lattice waveguides. Interesting examples presented include the snakelike and spiraling solitons that both can be adaptively induced in sinusoidally and helically shaped optical lattices. The controlled propagation paths provide an excellent opportunity for various applications, including optical switches and signal transmission, among others.A tip nanofocusing light field, with high electric-field intensity and nanoscale mode volume, can significantly improve nonlinear light scattering efficiency, thereby greatly promoting the development of strong-field nano-optics. Here, tip-enhanced four-wave mixing (FWM) is theoretically analyzed through two ultrafast radial vector beams internally illuminating an Ag-coated silica tip (ACST). Two femtosecond pulses, with radial electric vectors and pulse width of 100 fs, are adopted as excitation sources to illuminate the ACST. Degenerate tip-enhanced FWM (ωFWM = 2ω1-ω2) with a nonlinear conversion efficiency of ∼10-5 is achieved. The peak electric-field amplitude of the two pump pulses is 5 × 107 V/m, which is two orders of magnitude lower than that of the external excitation method. Further theoretical analysis shows that the conversion efficiency of the tip-enhanced FWM has strict frequency detuning dependence characteristics, and is closely related to the frequency response of the tip nanofocusing light field. This plasmonic tip provides an approach for enhancing nonlinear nano-optics, and may be used in the field of tip-based FWM nanoscopy.We measure the molecular alignment induced in gas using molecular rotational echo spectroscopy. Our results show that the echo intensity and the time interval between the local extremas of the echo responses depend sensitively on the pump intensities and the initial molecular rotational temperature, respectively. This allows us to accurately extract these experimental parameters from the echo signals and then further determine the molecular alignment in experiments. The accuracy of our method has been verified by comparing the simulation with the extracted parameters from the molecular alignment experiment performed with a femtosecond pump pulse.Using numerical simulation, we have investigated the generation of color solitons consisting of two radiation fragments with different carrier frequencies in a dual-wavelength laser. The proposed mechanism for the formation of such solitons involves nonlinear losses that increase with increasing intensity, the dispersion of the refractive index, spectral gain inhomogeneity, and the generation of a doublet radiation spectrum, owing to the corresponding spectral-dependent losses in the laser. The proposed theory explains the main features of the experimentally observed formation of color domains in fiber lasers and has the potential for further development of methods for controlling the nonlinear dynamics of laser radiation.Surface topology measurements of micro- or nanostructures are essential for both scientific and industrial applications. However, high-throughput measurements remain challenging in surface metrology. We present single-shot full-field surface topography measurement using Kramers-Kronig holographic imaging and spectral multiplexing. Three different intensity images at different incident angles were simultaneously measured with three different colors, from which a quantitative phase image was retrieved using spatial Kramers-Kronig relations. A high-resolution topographic image of the sample was then reconstructed using synthetic aperture holography. Various patterned structures at the nanometer scale were measured and cross-validated using atomic force microscopy.The rotational Doppler effect can be exploited in laser rotational Doppler velocimetry to detect the angular velocity of a moving object. Recently, its vectorial counterpart was revealed, which uses vectorial polarization fields and shows the potential to retrieve the full vectorial motion information of a moving object. Here, we further develop the general model for direction-discriminated rotational Doppler velocimetry by considering two optical degrees of freedom (DoFs), i.e., the orbital angular momentum (OAM) and polarization. Analyses indicate that the two optical DoFs of light play different roles in rotational velocity measurement. On the one hand, the OAM DoF enables the detection of the magnitude of rotational velocity; on the other hand, the circular polarization DoF facilitates the determination of the rotation direction by analyzing the relative phase difference between two intensity signals of the superposed light field after two polarizers. We demonstrate an interferometric scheme with two orthogonally circularly polarized beams of opposite OAM for detecting a rotating small object. These demonstrations may provide abundant alternatives for achieving robust Doppler velocimetry in more complicated sensing and metrology applications.Fourier single-pixel imaging (FSI) allows an image to be reconstructed by acquiring the Fourier spectrum of the image using a single-pixel detector. Fast FSI is typically achieved by acquiring a truncated Fourier spectrum, that is, only low-frequency Fourier coefficients are acquired, with the high-frequency coefficients discarded. However, the truncation of the Fourier spectrum leads to undesirable ringing artifacts in the resulting image. Ringing artifacts produce false edges in the image and reduce the image contrast, resulting in image quality degeneration. The artifact is particularly severe in dynamic FSI, where the sampling ratio is generally ultra-low. We propose an effective and fast deringing algorithm to achieve ringing-free fast FSI. The algorithm eliminates ringing artifacts through 2D sub-pixel shifting and preserves image details through image fusion. Both static and dynamic imaging results demonstrate that the proposed method can reconstruct ringing-free images from under-sampled data in FSI. The deringing algorithm not only provides FSI with the capability of fast high-quality single-pixel imaging but also might prove its applicability in other areas, such as Fourier-based data compression algorithms.Solar panels are being increasingly used as detectors in underwater wireless optical communication (UWOC) systems, as the large detection area can significantly simplify the link alignment. However, the greatest problem in such a scheme is the limited bandwidth of the solar panel, which was originally optimized for energy harvesting rather than communication. In this Letter, we propose series-connected solar arrays for high-speed underwater detection, by taking a deep dive into the fundamentals of the solar array. As the size of the solar array increases from 1×1 to 3×3, the -20-dB bandwidth increases from 4.7 MHz to 24.2 MHz. To further improve the frequency response, a reverse bias is applied on the array. With a reverse bias voltage of 90 V, the -20-dB bandwidth of the proposed 3×3 solar array is extended to 63.4 MHz. To the best of our knowledge, it is the highest bandwidth achieved among the reported solar panel-based optical communication systems with a large detection area. Using the proposed series-connected solar array, a data rate of 150 Mbps is achieved over a 35-m underwater channel with a frequency domain equalizer. The proposed system shows that off-the-shelf solar cells have great potential in high data rate UWOC systems.
Tibial plateau fractures are often complex, and they can be challenging to treat. Classifying fractures is often part of the treatment process, but intra- and interobserver reliability of fracture classification systems often is inadequate to the task, and classifications that lack reliability can mislead providers and result in harm to patients. Three-dimensionally (3D)-printed models might help in this regard, but whether that is the case for the classification of tibial plateau fractures, and whether the utility of such models might vary by the experience of the individual classifying the fractures, is unknown.
(1) Does the overall interobserver agreement improve when fractures are classified with 3D-printed models compared with conventional radiology? (2) Does interobserver agreement vary among attending and consultant trauma surgeons, senior surgical residents, and junior surgical residents? (3) Do surgeons' and surgical residents' confidence and accuracy improve when tibial plateau fractures are claconfidence in classifying fractures or accuracy with 3D-printed models; confidence was high (about 7 points on a 10-point scale) as rated by all observers, despite moderate or worse accuracy and interobserver agreement.
Although 3D-printed models minimally improved the overall interobserver agreement for two of three classification systems, none of the classification systems achieved more than moderate interobserver agreement. This suggests that even with 3D-printed models, many fractures would be misclassified, which could result in misleading communication, inaccurate prognostic assessments, unclear research, and incorrect treatment choices. Therefore, we cannot recommend the use of 3D-printed models in practice and research for classification of tibial plateau fractures.
Level III, diagnostic study.
Level III, diagnostic study.
With stressors that are often associated with suicide increasing during the coronavirus disease 2019 (COVID-19) pandemic, there has been concern that suicide mortality rates may also be increasing. Our objective was to determine whether suicide mortality rates increased during the COVID-19 pandemic.
We conducted an interrupted time-series study using data from January 2019 through December 2020 from 2 large integrated health care systems. The population at risk included all patients or individuals enrolled in a health plan at HealthPartners in Minnesota or Henry Ford Health System in Michigan. The primary outcome was change in suicide mortality rates, expressed as annualized crude rates of suicide death per 100,000 people in 10 months following the start of the pandemic in March 2020 compared with the 14 months prior.
There were 6,434,675 people at risk in the sample, with 55% women and a diverse sample across ages, race/ethnicity, and insurance type. From January 2019 through February 2020, there was a slow increase in the suicide mortality rate, with rates then decreasing by 0.45 per 100,000 people per month from March 2020 through December 2020 (SE=0.19, P=0.03).
Overall suicide mortality rates did not increase with the pandemic, and in fact slightly declined from March to December 2020. Our findings should be confirmed across other settings and, when available, using final adjudicated state mortality data.
Overall suicide mortality rates did not increase with the pandemic, and in fact slightly declined from March to December 2020. Our findings should be confirmed across other settings and, when available, using final adjudicated state mortality data.
An improved understanding of the coronavirus disease 2019 (COVID-19) pandemic is needed to identify predictors of outcomes among older adults with COVID-19.
The objective of this study was to examine patient and health system factors predictive of in-hospital mortality, intensive care unit (ICU) admission, and readmission among patients with COVID-19.
A cohort study of patients aged 18 years and older with COVID-19 discharged from 5 New York hospitals within the Mount Sinai Health System (March 1, 2020-June 30, 2020).
Patient-level characteristics (age, sex, race/ethnicity, comorbidities/serious illness, transfer from skilled nursing facility, severe acute respiratory syndrome coronavirus 2 viral load, Sequential Organ Failure Assessment score, treatments); hospital characteristics.
All-cause in-hospital mortality; ICU admission; 30-day readmission.
Among 7556 subjects, mean age 61.1 (62.0) years; 1556 (20.6%) died, 949 (12.6%) had an ICU admission, and 227 (9.1%) had a 30-day readmission. Increasursing facility were half as likely to be admitted to the ICU. This finding requires further investigation to understand how age and treatment preferences factored into resource allocation.
Increased age was the single greatest independent risk factor for mortality. Comorbidities and serious illness were independently associated with mortality. Understanding these risk factors can guide medical decision-making for older adults with COVID-19. Older adults and those admitted from a skilled nursing facility were half as likely to be admitted to the ICU. This finding requires further investigation to understand how age and treatment preferences factored into resource allocation.
Chronic noncancer pain (CNCP) affects millions of individuals in the United States but evidence of its prevalence among caregivers of children with special health care needs is sparse. We sought to estimate the prevalence of CNCP and its association with caregiver burden, in a nationally representative sample.
Retrospective cross-sectional study using pooled Medical Expenditure Panel Survey data for 2010-2015. Within interviewed households, family groups consisting of at least 1 parent and 1 child (0-17 y) were identified. CNCP was identified by one or more International Classification of Diseases, Ninth Revision (ICD-9)-CM codes utilizing previously published approaches. Level of caregiver burden was defined using a validated screener questionnaire identifying children with high burden of care (ie, special health care needs), for example, high or low burden. We estimated prevalence of CNCP as a function of caregiver burden, as well as the association of risk factors with CNCP, including parent sociodemographic features, clinical diagnoses, and family level characteristics.
We identified 46,525 caregivers of whom 3.6% reported experiencing high caregiving burden. The prevalence of CNCP was 25.5% and 14.0% among parents with high compared with low caregiving burden, respectively. Odds of CNCP were higher among parents with high compared to those with lower caregiver burden (odds ratio=1.29, 95% confidence interval=1.06-1.55). Being obese, experiencing disability, and having a mental health diagnosis were associated with higher odds of CNCP.
Chronic pain is more common among caregivers with high caregiver burden. Our findings highlight the need to further explore the nature and impact of risk factors on caregiver health and disability.
Chronic pain is more common among caregivers with high caregiver burden. Our findings highlight the need to further explore the nature and impact of risk factors on caregiver health and disability.
The coronavirus disease 2019 (COVID-19) pandemic has challenged the accuracy and racial biases present in traditional mortality scores. An accurate prognostic model that can be applied to hospitalized patients irrespective of race or COVID-19 status may benefit patient care.
This cohort study utilized historical and ongoing electronic health record features to develop and validate a deep-learning model applied on the second day of admission predicting a composite outcome of in-hospital mortality, discharge to hospice, or death within 30 days of admission. Model features included patient demographics, diagnoses, procedures, inpatient medications, laboratory values, vital signs, and substance use history. Conventional performance metrics were assessed, and subgroup analysis was performed based on race, COVID-19 status, and intensive care unit admission.
A total of 35,521 patients hospitalized between April 2020 and October 2020 at a single health care system including a tertiary academic referral center aomes on the second day of admission in the general inpatient population without significant racial bias.
The purpose of this quality improvement project was to determine if head immobilization, pressure redistribution for the occiput, and offloading of pressure from craniotomy incisions could be improved by utilizing fluidized positioners instead of pillows previously used as the standard of care. The second purpose was to determine cost savings for the organization.
Eight patients with head trauma and craniotomy in a surgical intensive care unit (SICU) and cardiovascular intensive care unit (CVICU) from a level 1 trauma center in the Southeast region of the United States participated over a 6-month period.
The project comprised educating staff including nurses, nursing assistants, supervisors, and care managers, and implementation of the head positioner from July 2018 to December 2018. Staff from the SICU and CVICU, a step-down unit, and a neurological ICU were also educated on the fluidized positioner, because patients were transferred to these units when stable. All patients who underwent craniotomy surgery were placed on the fluidized positioner postoperatively until immobilization and offloading were no longer required.
During the initial 6-month evaluation period, no new pressure injuries or incisional trauma occurred in the 8 patients. The economic impact to treat one hospital-acquired unstageable pressure injury was estimated at $78,722. Because no new occipital pressure injuries occurred in the 8 patients placed on the fluidized head positioner, the hospital potentially saved $629,776.
Findings from the project suggest that implementation of a fluidized positioner can redistribute pressure to the occiput, offload craniotomy incision sites, and prevent pressure injuries.
Findings from the project suggest that implementation of a fluidized positioner can redistribute pressure to the occiput, offload craniotomy incision sites, and prevent pressure injuries.The conjecture of Grosse-Kunstleve et al. [(1996), Acta Cryst. A52, 879-889], that coordination sequences of periodic structures in n-dimensional Euclidean space are rational, is proved. This has been recently proven by Nakamura et al. [(2021), Acta Cryst. A77, 138-148]; however, the proof presented here is a straightforward application of classic techniques from automata theory.A formula for the calculation of the number of Wyckoff sequences of a given length is presented, based on the combinatorics of multisets with finite multiplicities and a generating function approach, assuming a certain space-group type and taking into account the number of non-fixed and fixed Wyckoff positions, respectively. The formula is applied to the 44 distinguishable combinatorial types of the 230 space-group types. A comparison is made between the calculated frequencies of occurrence of Wyckoff sequences of given space-group type and length and the observed ones for actual crystal structures, as retrieved from the Pearson's Crystal Data Crystal Structure Database for Inorganic Compounds.The coincidence site lattice (CSL) is important for characterizing the structure and energy state of grain boundaries in polycrystalline materials. A simplified relationship between the modified O-lattice and the corresponding rotation matrix is proposed to establish a general formula for the CSL and the near coincidence site lattice (NCSL) in Bravais lattice systems. The general formula paves the way to computer simulation and crystallographic analysis of grain boundaries.A method is described for generating and exploring tangled piecewise-linear embeddings of trivalent graphs under the constraints of point-group symmetry. It is shown that the possible vertex-transitive tangles are either graphs of vertex-transitive polyhedra or bipartite vertex-transitive nonplanar graphs. One tangle is found for 6 vertices, three for 8 vertices (tangled cubes), seven for 10 vertices, and 21 for 12 vertices. Also described are four isogonal embeddings of pairs of cubes and 12 triplets of tangled cubes (16 and 24 vertices, respectively). Vertex 2-transitive embeddings are obtained for tangled trivalent graphs with 6 vertices (two found) and 8 vertices (45 found). Symmetrical tangles of the 10-vertex Petersen graph and the 20-vertex Desargues graph are also described. Extensions to periodic tangles are indicated. These are all interesting and viable targets for molecular synthesis.The determination of the independence ratio of a periodic net requires finding a subgroup of the translation group of the net for which the quotient graph and a fundamental transversal have the same independence ratio; the respective motif defines a periodic factor of the net. This article deals with practical issues regarding the calculation of the independence ratio of mainly 2-periodic nets, with an application to the 200 2-periodic nets listed on the RCSR (Reticular Chemistry Structure Resource) site. A companion paper described a calculation technique of independence ratios of finite graphs based on propositional calculus. This paper focuses on criteria for the choice of the translation subgroup and of the transversal. The translation subgroup should be chosen in such a way as to eliminate every cycle in the quotient graph that is shorter than structural cycles, or rings, of the net. Topological constraints provide an upper bound to the independence ratio of 2-periodic nets and mostly enable the determination of the associated factor, thus giving a description of a periodic distribution in saturated solid solutions obeying some avoidance rule.Considered are 80 sets of layer groups, each set consisting of four groups ordinary single and double, and grey single and double layer groups. The structural properties of layer groups (factorization into cyclic subgroups and the existence of grading according to the sequence of halving subgroups) enable efficient symbolic computation (by the POLSym code) of the relevant properties, real and complex irreducible and allowed (half-)integer (co-)representations in particular. This task includes, as the first step, classification of the irreducible domains based on the group action in the Brillouin zone combined with torus topology. Also, the band (co-)representations induced from the irreducible (co-)representations of Wyckoff-position stabilizers (site-symmetry groups) are decomposed into the irreducible components. These, and other layer group symmetry related theoretical data relevant for physics, layered materials in particular, are tabulated and made available through the web site https//nanolab.group/layer/.The two commonly used systems of magnetic space-group (MSG) symbols, with accompanying numbers and settings, are those of Belov-Neronova-Smirnova (BNS) and Opechowski-Guccione (OG). The symbols from both systems have been used for several decades now. Both have advantages and disadvantages. Both present challenges of interpretation to novice and expert users alike, which can inhibit understanding and lead to errors in published magnetic structures. To address each of these challenges going forward, a new unified (UNI) MSG symbol is introduced, which combines a modified BNS symbol with essential information from the OG symbol.
The aim of this study was to report the rationale and selection criteria for hemithyroidectomy and ipsilateral central neck dissection in patients with selected papillary thyroid cancer and to report the surgical and oncological outcomes.
Single-institution retrospective observational study.
The clinical records of patients with a histopathological diagnosis of low-risk pT1 papillary thyroid cancer who underwent hemithyroidectomy with or without ipsilateral central neck dissection between March 2000 and April 2018 at a tertiary referral center were retrospectively reviewed. Demographic, clinical, and histopathological data were collected.
During the study period, 176 patients underwent hemithyroidectomy for PTC. Thirteen patients (13/176, 7.39%) were lost to follow-up and 74 patients (74/163 45.40%) underwent completion thyroidectomy within 1 month because they were classified intermediate ATA initial risk based on definitive pathology. The final study group was composed of 89 patients, who had a medipapillary thyroid cancers and ensures a low risk of recurrence. Prophylactic ipsilateral central compartment dissection could have a role in improving cancer staging, and accurate ultrasonographic follow-up is essential to identify local recurrence.
Diabetic osteoporosis is a common metabolic bone disorder characterized by bone loss in diabetic patients, which causes an enormous social burden due to the unsatisfactory outcome of current therapeutic strategy.
Based on the importance of inflammasome activation in diabetic osteoporosis, we evaluated the protective effect of an antioxidant, rosmarinic acid (RA) in diabetic osteoporosis. Bone marrow-derived monocytes isolated from rats were treated with receptor activator of nuclear factor kappa-Β ligand (RANKL) and macrophage colony stimulating factor to differentiate into mature osteoclasts (OCs). Next OCs were stimulated with RA under high glucose condition to evaluate bone resorption. Next, streptozotocin (STZ)-injected rats were orally treated with 50 mg kg-1 RA to analyze its effect on diabetic osteoporosis.
RA inhibited high glucose-stimulated inflammation and inflammasome activation in OCs. Bone resorption was also reduced after RA treatment as shown by the resorption pits assay. Moreover, RA significantly reduced bone resorption, alleviated bone weight loss and increased bone mineral density by inhibiting the activation of NACHT-LRR-PYD domains-containing protein 3 (NLRP3) inflammasome in STZ-induced diabetic rats, leading to the improvement of diabetic osteoporosis.
RA effectively ameliorates diabetic osteoporosis in STZ-induced rats by inhibiting the activation of NLRP3 inflammasome in OCs, which suggests that RA might serve as a potential candidate drug for treating diabetic osteoporosis.
RA effectively ameliorates diabetic osteoporosis in STZ-induced rats by inhibiting the activation of NLRP3 inflammasome in OCs, which suggests that RA might serve as a potential candidate drug for treating diabetic osteoporosis.
Endogenous gaseous substances, such as NO and CO have been found to be effective vasodilators earlier. H2S has been identified as an additional one, however, for that substance both vasodilatory and vasoconstrictor responses have been described in different vascular territories. Our aim was to examine the effect of hydrogen sulfide on the tone of cerebral arterioles and some aspects of its mechanism.
The work was performed on excised rat anterior cerebral artery segments in vitro (diameter range 150-250 µm), using a pressure myograph system. We used NaHS as exogenous H2S donor, propargylglycine (PAG) to abolish the endogenous synthesis of hydrogen sulfide and 4,4'-Diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS) to examine the potential role of Cl-/HCO3 - exchanger in the effects of H2S. The time course of the events after application of exogenous H2S was also evaluated.
Our findings revealed that in these pathologically important vessels (1) endogenously produced H2S is not a vasodilator, but a moderate vasoconstrictor; (2) H2S has a biphasic effect low concentrations are moderate vasoconstrictors, while at higher concentrations the initial contraction is followed by dilatation; (3) that vasodilation is prevented by DIDS (4,4'-Diisothiocyanatostilbene-2,2'-disulfonic acid disodium, an inhibitor of the Cl-/HCO3 - exchanger).
These studies confirm that H2S should be taken into consideration as a modulator of cerebral arteriolar tone in mammals.
These studies confirm that H2S should be taken into consideration as a modulator of cerebral arteriolar tone in mammals.
Patients with chronic obstructive pulmonary disease (COPD) are a vulnerable group in terms of the outcome of coronavirus infection in relation to their disease or its treatment, with a higher risk of developing serious complications compared to the healthy population.
The aim of our summary study is to review the background and health outcomes of chronic obstructive pulmonary disease and COVID-19 infection in the presence of both diseases.
Review of national and international medical databases (PubMed, MEDLINE, and MOB) with keywords COPD, COVID-19, disease risk, cause, prevention, complications, and prognosis.
Meta-analyses show that COPD is one of the most common underlying conditions in patients hospitalized for COVID-19. Such patients are five times more likely to develop a serious complication due to oxygen supply problems therefore they are more likely to be admitted to intensive care units, where they may require mechanical ventilation. In the case of underlying COPD, the usual care plan for COVID-19 infection should be followed, as well as all public health recommendations to minimize the risk of developing and transmitting COVID-19.
Coronavirus infection is especially dangerous for COPD patients, who are much more likely to become seriously ill, so increased surveillance, prevention, early detection, adequate treatment and rehabilitation of the disease group are of paramount importance.
Coronavirus infection is especially dangerous for COPD patients, who are much more likely to become seriously ill, so increased surveillance, prevention, early detection, adequate treatment and rehabilitation of the disease group are of paramount importance.The question of systematic use of a pharmacological treatment before surgery in patients diagnosed with pheochromocytoma and paraganglioma (PPGL) remains highly controversial. While recent guidelines suggest that this should be used in all patients, some experienced teams consider it unnecessary in some cases, provided the surgery is performed in a dedicated center that has expert endocrinologists, cardiologists, surgeons, and anesthetists. This controversy is aimed at shedding light on the potential benefits and risks of such a treatment, focusing specifically on alpha blockers which are considered as the first-line medical treatments in patients with PPGL. After discussing the rationale for alpha blockers, hemodynamic instability, tolerance, and acute cardiac complications will then be discussed in the first part of the manuscript, defending a systematic use. The second section will focus on blood pressure control, tolerance of alpha blockers, and also the management of normotensive PPGL, examining the daily risks of PPGL and arguing against the systematic use of a preoperative pharmacological treatment before surgery. Finally, we will discuss the concept of expert centers and define the patients in whom the risk/benefit profile would favor the use of this preoperative treatment.
This study investigated the use of fixed-wing air ambulance in Iceland between 2012 and 2020.
Medical records were filled out during each flight and information afterwards entered into an electronic database.
The annual number of patient transports nationwide; triage scale category; reason for transportation, age and gender; and departure and arrival airports were analyzed. Response time and total transport time were compared between years and locations. Poisson regression analysis was used to compare the yearly number of transports. One-way ANOVA was used to compare response time and total transport time by year and departure site.
In total, 6011 patients were transported in fixed-wing air ambulances during the study period. Majority were male (54.3%). Median age was 64 years (range 0-99 years). Most patients were transported due to medical conditions; 15.8% due to trauma. Thirty percent of women aged 20 to 44 years were transported due to pregnancy or childbirth. Two-thirds of patients were transported to Reykjavik (n=3937), and one-fifth to Akureyri (n=1139). Median response time for acute transports was 84 minutes (range 0-2870 minutes). Median total transport time was 150 minutes (range 50-2930 minutes). Differences were found in total transport time from departure locations (F=32.19; DF 9, 2678; p<0,001). Egilsstaðir, Norðfjörður, Höfn, and, partly, Ísafjörður had the longest total transport times.
Icelandic air ambulance flights are often long, likely affecting outcomes for patients with time-sensitive medical conditions. Access to specialized healthcare is unequal among places of residence, and it is important to address this.
Icelandic air ambulance flights are often long, likely affecting outcomes for patients with time-sensitive medical conditions. Access to specialized healthcare is unequal among places of residence, and it is important to address this.
The bacterial genus Bacillus is widely distributed environmentally and is usually considered a low-virulence organism, except for B. anthracis. A blood culture positive for Bacillus is often looked at as contamination. Nevertheless, B. cereus can cause invasive infections in humans and produces harmful toxins. The epidemiology of these infections remains poorly studied.
All possible invasive infections caused by Bacillus during 2006-2018 at Landspitali University Hospital were identified from culture results. Clinical information was used to evaluate if there was a possible infection or confirmed infection. Here, the authors propose and use clinical criteria to categorize each case as contamination, possible infection or confirmed infection. The incidence of possible or confirmed infections was calculated using hospital catchment population data.
Positive cultures of Bacillus sp. from sterile sites during 2006-2018 were identified from 126 patients; blood (116), synovial fluid (8) and cerebrospinal fluifection to establish diagnosis and avoid unnecessary antibiotic therapy.
Graves' disease is an autoimmune disease in which autoantibodies cause an increase in the production of thyroid hormones, and is the most common cause of thyrotoxicosis in children. Symptoms in children are often more obscure than in adults. The aim of the study is to assess the incidence of Graves' disease in children and adolescents in Iceland over the span of two decades (2001-2021), and furthermore to investigate if the incidence rate has increased, as well as to describe treatment options and disease recurrence.
This retrospective descriptive study included all children diagnosed with Graves' disease in the years 2001-2021 in Iceland. Information was obtained from the Directorate of Health's drug database and from ICD-10 diagnoses at Landspítali - The National University Hospital.
In total, 57 children and adolescents were diagnosed with Graves', the overall incidence rate was 3.5/100,000 person-years. Gender ratio was 12.7 (male female) and the mean age at diagnosis was 13.6 for boys and 13.9 yeas the most common permanent treatment option. Disease recurrence was common. A possible relationship between the duration of the original drug therapy and disease recurrence should be investigated.
Despite the availability of effective treatment, the control of hypertension remains insufficient. Telemonitoring in the management of hypertension would be an effective way to improve blood pressure control.
The aim of our study will be to evaluate the effects of telemonitoring with antihypertensive treatment titration on blood pressure control in Tunisian patients with hypertension.
Our trial will be a prospective, rater-blinded randomized controlled trial carried out with primary care physicians in the Sahel region of Tunisia. Patients will be eligible for enrollment if they are aged over 35 years, are newly diagnosed with hypertension, or are known to be poorly controlled on antihypertensive therapy. Participants will be randomly assigned in a 11 ratio to the telemonitoring arm or usual care arm. The telemonitoring arm will involve a weekly telephone call for the collection of the home blood pressure measurements, therapeutic education, and treatment compliance assessment as well as a monthly call fuld shed some light on the feasibility and impact of telemonitoring and self-monitoring in a Tunisian population of patients with hypertension who consult primary care physicians.
ClinicalTrials.gov NCT04607239; https//clinicaltrials.gov/ct2/show/NCT04607239.
DERR1-10.2196/26184.
DERR1-10.2196/26184.
Smoking rates in Canada remain unacceptably high, and cessation rates have stalled in recent years. Online cessation programs, touted for their ability to reach many different populations anytime, have shown promise in their efficacy. The Government of Canada has therefore funded provincial and national smoking cessation websites countrywide. However, little is known about the behavior change techniques (BCTs) that underpin the content of these websites, which is key to establishing the quality of the websites, as well as a way forward for evaluation.
The purpose of this study, therefore, is to apply the BCTTv1 taxonomy to Canadian provincial and federal websites, and to determine which BCTs they use.
A total of 12 government-funded websites across Canada were included for analysis. Using deductive content analysis and through training in applying the BCTTv1 taxonomy, the website content was coded according to the 93 BCTs across the 16 BCT categories.
Of the 16 BCT categories, 14 were present within ts smoking cessation outcomes in relation to the web-based content.
Detection of depression gained prominence soon after this troublesome disease emerged as a serious public health concern worldwide.
This systematic review aims to summarize the findings of previous studies concerning applying machine learning (ML) methods to text data from social media to detect depressive symptoms and to suggest directions for future research in this area.
A bibliographic search was conducted for the period of January 1990 to December 2020 in Google Scholar, PubMed, Medline, ERIC, PsycINFO, and BioMed. Two reviewers retrieved and independently assessed the 418 studies consisting of 322 articles identified through database searching and 96 articles identified through other sources; 17 of the studies met the criteria for inclusion.
Of the 17 studies, 10 had identified depression based on researcher-inferred mental status, 5 had identified it based on users' own descriptions of their mental status, and 2 were identified based on community membership. The ML approaches of 13 of the 17 studies were supervised learning approaches, while 3 used unsupervised learning approaches; the remaining 1 study did not describe its ML approach. Challenges in areas such as sampling, optimization of approaches to prediction and their features, generalizability, privacy, and other ethical issues call for further research.
ML approaches applied to text data from users on social media can work effectively in depression detection and could serve as complementary tools in public mental health practice.
ML approaches applied to text data from users on social media can work effectively in depression detection and could serve as complementary tools in public mental health practice.