Astrupbennedsen5068

Radicals are abundant in a range of important gas-phase environments. They are prevalent in the atmosphere, in interstellar space, and in combustion processes. As such, understanding how radicals react is essential for the development of accurate models of the complex chemistry occurring in these gas-phase environments. By controlling the properties of the colliding reactants, we can also gain insights into how radical reactions occur on a fundamental level. Recent years have seen remarkable advances in the breadth of experimental methods successfully applied to the study of reaction dynamics involving paramagnetic species-from improvements to the well-known crossed molecular beams approach to newer techniques involving magnetically guided and decelerated beams. Coupled with ever-improving theoretical methods, quantum features are being observed and interesting insights into reaction dynamics are being uncovered in an increasingly diverse range of systems. In this highlight article, we explore some of the exciting recent developments in the study of chemical dynamics involving paramagnetic species. We focus on low-energy reactive collisions involving neutral radical species, where the reaction parameters are controlled. We conclude by identifying some of the limitations of current methods and exploring possible new directions for the field.Selectivity is one of the most crucial figures of merit in trace gas sensing, and thus a comprehensive assessment is necessary to have a clear picture of sensitivity, selectivity, and their interrelations in terms of quantitative and qualitative views. Recent reviews on gas sensors/techniques are limited to specific sensors, sensors with unconventional materials, various technological exploitation, or specific applications. However, the selectivity is either unexplored in most cases or explained concerning the materials/techniques involved in a demonstration. Therefore, there is a pressing need to identify the possible ways to improve the selectivity of a gas sensor/technique with low or zero cross-sensitivity to other compounds/gases present in the working environment. Analytical techniques involving spectroscopic and mass-spectrometry-based methods are excellent in selectivity but have limited applicability for field deployment compared to the miniatured solid state sensors. Solid state sensors are the mainly studied gas sensors due to their flexibility, portability, and cost-effectiveness, and being technologically favorable but suffer from low selectivity in harsh and humid environments. This review will evaluate the limitations and possible solutions to selectivity issues in a wide variety of gas sensors. Here, we have discussed the gas-sensor technologies and underlying sensing mechanisms in two main groups - spectroscopic and non-spectroscopic. Recent state-of-the-art techniques and fundamental challenges are discussed to improve the selectivity and other gas sensor indicators and future perspectives.

To characterize red-green and tritan color discrimination in eyes with macular telangiectasia Type II (MacTel).

Color discrimination was assessed by metameric matching methods using an Oculus MR Anomaloscope. Red-green color discrimination was assessed using the Rayleigh equation, and tritan color discrimination was assessed using the Moreland equation. Results were expressed as anomalquotient (AQ) and tritanomalquotient (TAQ) units, respectively.

Seventeen eyes with MacTel were compared with 16 control eyes with normal vision. Twelve eyes with MacTel demonstrated abnormal color matches; except for two eyes with red-shifted Rayleigh matches, the primary abnormality evident was reduced color discrimination. On average, Rayleigh matching ranges were significantly widened in MacTel (0.518 ± 0.066 AQ units) compared with normal (0.14 ± 0.03 AQ units; P < 0.0001). Similarly, Moreland matching ranges were significantly wider (0.794 ± 0.109 TAQ units) than normal control subjects (0.204 ± 0.070 TAQ units; P < 0.0001). Losses in color discrimination did not correlate significantly with the best-corrected visual acuity, although Moreland matching ranges were significantly correlated to Rayleigh matching ranges.

MacTel results in a combined acquired red-green and tritan color vision deficiency. A minority of eyes demonstrated red-shifted Rayleigh matches, consistent with decreases in cone photopigment optical density.

MacTel results in a combined acquired red-green and tritan color vision deficiency. A minority of eyes demonstrated red-shifted Rayleigh matches, consistent with decreases in cone photopigment optical density.

To test the hypothesis that Müller cell dysfunction in macular telangiectasia type 2 (MacTel) results in delayed cone adaptation kinetics and to assess absolute cone and rod thresholds in this condition.

Adaptation after an approximate 63.5% full-field cone photopigment bleach was assessed for Goldmann size V (1.7° diameter) 640 nm (red) and 480 nm (blue) targets presented at a retinal locus corresponding to 2° temporal to fixation. The cone time constant of adaptation and absolute cone and rod thresholds were calculated from exponential functions fitted to the resultant dark adaptation curves.

Eighteen eyes with MacTel (from 11 patients) were compared with 19 control eyes (from 16 normal subjects). Cone adaptation kinetics were significantly impaired in MacTel, as was the absolute cone threshold. Final thresholds for blue targets were also significantly elevated in MacTel, consistent with impaired rod absolute threshold. Losses in sensitivity observed in MacTel were consistent with a so-called d1/2 mechanism (i.e., receptoral) site of sensitivity loss.

In addition to previously documented impairments in rod dark adaptation, MacTel results in a significant elevation in cone thresholds because of pathology at the level of the photoreceptors. Vistusertib ic50 The delays in cone adaptation that we found in eyes with MacTel may reflect impairment of the Müller cell-mediated cone-specific visual cycle.

In addition to previously documented impairments in rod dark adaptation, MacTel results in a significant elevation in cone thresholds because of pathology at the level of the photoreceptors. The delays in cone adaptation that we found in eyes with MacTel may reflect impairment of the Müller cell-mediated cone-specific visual cycle.

To investigate the frequency, risk factors, and functional prognosis of chorioretinal atrophy (CRA) in vitreoretinal lymphoma (VRL).

This was a retrospective cohort study of consecutive patients with vitreoretinal lymphoma. The demographic, clinical, and retinal features and the treatment modalities of each patient were collected. The charts and the multimodal imaging at each visit were reviewed. The risk factors associated with CRA were investigated with a mixed-model Cox regression.

Of the 79 eyes of 40 patients included, 41 eyes (52%) had CRA; 27 and 14 eyes had focal and diffuse CRA, respectively. The rate of vitreoretinal lymphoma lesions in the macula was similar between focal and diffuse CRA (96% vs. 93%). The eyes with CRA had worse best-corrected visual acuity (P = 0.006) than eyes with no CRA; diffuse atrophy had the worst best-corrected visual acuity (P < 0.001). The presence of retinal infiltrates (hazard ratio = 3.75, 95% confidence interval [CI] 1.46-9.59, P = 0.006) and vertical hyperreflective lesions (hazard ratio= 4.13 95% CI 1.14-14.93, P = 0.03) on optical coherence tomography and macular involvement (hazard ratio = 6.59, 95% CI 1.41-30.53, P = 0.02) were associated with a higher risk of CRA.

Vitreoretinal lymphoma presenting with retinal infiltrates and macular involvement carried a higher risk of CRA. Risk factors for CRA should be identified for the potential of severe visual loss. Prompt diagnosis of vitreoretinal lymphoma may allow better control of the disease.

Vitreoretinal lymphoma presenting with retinal infiltrates and macular involvement carried a higher risk of CRA. Risk factors for CRA should be identified for the potential of severe visual loss. Prompt diagnosis of vitreoretinal lymphoma may allow better control of the disease.

To compare the anatomical and functional outcomes of silicone oil (SO)-filled foldable capsular vitreous body (FCVB) and SO endotamponade in vitrectomy for patients with no light perception after ocular trauma.

A total of 64 patients (64 eyes) with no light perception caused by severe ocular trauma were divided into FCVB and SO groups based on the surgical treatment. The main outcome measurements were retinal reattachment rate, intraocular pressure, best-corrected visual acuity, and number of operations.

Both the FCVB group (29 eyes) and the SO group (35 eyes) showed significant improvement in postoperative best-corrected visual acuity and intraocular pressure. The two groups showed no significant differences in final intraocular pressure and the retinal reattachment rate. The postoperative vision (≥LP) in the FCVB group was significantly worse than in the SO group (FCVB [4/29] vs. SO [18/35], P = 0.003). However, the number of surgeries in the FCVB group was significantly lower than in the SO group (FCVB [1.10] vs. SO [2.23], P < 0.001).

Vitrectomy combined with SO endotamponade shows better short-term improvement in the treatment of no light perception caused by severe ocular trauma. However, SO-filled FCVB can effectively prevent many complications caused by direct SO endotamponade, such as secondary surgeries or SO dependence.

Vitrectomy combined with SO endotamponade shows better short-term improvement in the treatment of no light perception caused by severe ocular trauma. However, SO-filled FCVB can effectively prevent many complications caused by direct SO endotamponade, such as secondary surgeries or SO dependence.

To explore the characteristics and underlying mechanisms of myopic traction maculopathy (MTM) with axial length less than 26.5 mm and to assess the effectiveness of macular buckling for the treatment of MTM.

Thirty-eight MTM eyes with axial length less than 26.5 mm were prospectively enrolled. Thirty-one eyes received surgery, and they were followed up for at least 6 months. Characteristics of MTM and surgical outcomes were evaluated.

Of the MTM eyes, 92.11% (35/38) showed posterior staphyloma. Narrow macular staphyloma was the most common type (54.29%, 19/35), followed by peripapillary (37.14%, 13/35). Three cases (8.57%) had wide macular staphyloma, and 44.74% of cases (17/38) had vitreoretinal traction. Twenty-two MTM eyes of type T3 underwent macular buckling surgery, and all the cases achieved foveal reattachment after the surgery. The mean best-corrected visual acuity improved significantly at the 6-month follow-up (P < 0.001). Nine MTM eyes of type T4 or T5 received combined surgery, all macular holes recovered, and the best-corrected visual acuity also improved postoperatively (P = 0.008) as of the 6-month visit.

Posterior staphyloma might serve as the initial force of the pathogenesis of MTM in eyes with axial length ˂26.5 mm. Macular buckling is a productive way to improve the MTM.

Posterior staphyloma might serve as the initial force of the pathogenesis of MTM in eyes with axial length ˂26.5 mm. Macular buckling is a productive way to improve the MTM.