Drewsingleton5451
The button sample holder provides a methodology that is complementary to the transmission cell and attenuated total reflection (ATR) techniques for infrared analyses of neat solids and liquids, and is especially useful for characterizing thick samples and high absorptivity bands.The geographical origin and processing month of green tea greatly affect its economic value and consumer acceptance. This study investigated the feasibility of combining near-infrared hyperspectral imaging (NIR-HSI) with chemometrics for the identification of green tea. Tea samples produced in three regions of Chongqing (southeastern Chongqing, northeastern Chongqing, and western Chongqing) for four months (from May to August 2020) were collected. Principal component analysis (PCA) was used to reduce data dimensionality and visualize the clustering of samples in different categories. Linear partial least squares-discriminant analysis (PLS-DA) and nonlinear support vector machine (SVM) algorithms were used to develop discriminant models. The PCA-SVM models based on the first four and first five principal components (PCs) achieved the best accuracies of 97.5% and 95% in the prediction set for geographical origin and processing month of green tea, respectively. This study demonstrated the feasibility of HSI in the identification of green tea species, providing a rapid and nondestructive method for the evaluation and control of green tea quality.The influence of three halogen elements F, Cl, Br on the fluorescent dyes were investigated by applying first principle calculations based on density functional method. We researched two aspects of absorption and emission and specifically analyzed the influence of halogen on the optical properties of molecules. First, the one-photon and two-photon absorption of these dyes were systematically investigated. Particularly, the two-photon absorption cross section were analysed. More important, the emission properties of these dyes were accurately researched by calculating wavelengths and fluorescence emission efficiencies. Furthermore, the fluorescence emission efficiencies of these molecules are accurately researched by calculating the radiative rate and the non-radiative decay rate. Our theoretical investigations reveal that the influence of halogen element on the optical properties of dyes, which achieved a more intuitive comparison of the luminous effects of these dye molecules.A sensitive fluorescent nanoprobe is reported for the determination of lamotrigine after its preconcentration by magnetic graphene oxide nanocomposite. The fluorescent nanoprobe is based on the quenching effect of lamotrigine on the nitrogen graphene quantum dots fluorescence at 440 nm, through strong hydrogen bonding. Under optimum conditions, the quenching fluorescent intensity of nitrogen graphene quantum dots shows linearity with the lamotrigine concentration in the range of 2.0-45.0 µg L-1, limits of detection (LOD), and quantification of 0.39 and 1.28 µg L-1 respectively. The parameters affecting the extraction and determination of lamotrigine were optimized via the central composite design (CCD) and one at the time method, respectively. The developed method was successfully employed for the extraction and quantification of lamotrigine in biological samples.Velpatasvir and sofosbuvir are new drugs prescribed in a combined pharmaceutical dosage form that pose a new challenge for the treatment of chronic hepatitis C. In this work, a comparative evaluation of the classical mathematical model, simultaneous equations, and the advanced mathematical model, partial least squares, for the spectrophotometric quantitative analysis of velpatasvir and sofosbuvir in bulk powder and in the new combined pharmaceutical dosage form was presented. The mathematical simultaneous equation method was used to resolve the overlap between velpatasvir and sofosbuvir. The absorbance and absorbativity values at 255 and 244.8 were used to construct two mathematical equations required for spectrophotometric quantitative analysis of the drugs under study. Partial least squares, an advanced mathematical tool dealing with the full spectral data of velpatasvir and sofosbuvir, was also introduced. An experimental design for the calibration sets and validation sets for the binary mixture of the drugs under study were created. The model was optimized based on a five-level, two-factor experimental design. Pre-processing of the spectral data was applied and resulted in the exclusion of the spectral region from 200 to 230 nm due to noise. The described methods were successfully applied to the spectrophotometric quantitative analysis of velpatasvir and sofosbuvir in Epclusa® tablets.
Frailty has been implicated as a negative predictor of Liver Transplant (LT) outcomes. see more However, an understanding of changes in patient muscle mass peri-LT, and their effect in high-acuity patients remains lacking.We examined the impact of perioperative muscle mass changes (ΔSMI) on high-acuity (MELD ≥35) LT recipients.
Skeletal muscle index (SMI) was calculated using CT imaging. Patients were divided into two groups, based on severity of peri-operative SMI decrease. LT recipients with chronic end-stage liver disease, MELD ≥35, and abdominal CT ≤30 days prior, and 30-90 days post LT were included. [1011 adult LT recipients reviewed, 2012-2018].
Of 1011 patients reviewed, 88 met inclusion criteria (median MELD 41.1). The median ΔSMI was -5.0 (-29.4 - +21.1 cm
/m
) (fig A). Patients were classified into two groups ΔSMI<-5.0 (median ΔSMI -0.4, n=44) and ΔSMI>-5.0 (median ΔSMI -9.2, n=44). Recipients with ΔSMI<-5.0 had higher pre-LT SMI (35.4 versus 31.2 cm
/m
, P <0.001) and lower post-LT SMI (26.0 versus 30.8 cm
/m
, P <0.001). The ΔSMI<-5.0 group had higher early allograft dysfunction (40.9 versus 20.5%, P=0.037), and inferior patient and graft survival (P=0.015, 0.017, respectively). Multivariate analysis identified ΔSMI<-5.0 (HR 2.938, P=0.048), long cold-ischemia time (≥9h, HR 7.332, P=0.008), HCV (HR 5.614, p=0.001), and tracheostomy after LT (HR9.218, P <0.001) as negative prognostic factors for patient survival .
Progressive perioperative sarcopenic deterioration was associated with inferior patient and graft survival in high acuity LT. These findings may guide pre and post-operative patient care and rehabilitation efforts in this challenging patient population.
Progressive perioperative sarcopenic deterioration was associated with inferior patient and graft survival in high acuity LT. These findings may guide pre and post-operative patient care and rehabilitation efforts in this challenging patient population.
Motor vehicle collisions (MVCs) are a leading cause of morbidity and mortality. However, there is limited evidence examining the effects seatbelt use has on MVC-related injuries and outcomes in patients with rib fractures. We aim to assess how seatbelt use affects associated injuries and outcomes in adult MVC patients with ≥2 rib fractures.
This retrospective study utilized the American College of Surgeons (ACS) Trauma Quality Programs (TQP) Participant Use File (PUF) Database. Drivers/passengers who sustained ≥2 rib fractures following an MVC and had an AIS ≤2 for extra-thoracic body regions were analyzed. Patients were then subdivided by presence of flail chest into two cohorts, which were subdivided according to injury severity score (ISS) and seatbelt use. Logistic and linear regression was used to assess the impact of seatbelt use on outcomes.
Among both low and intermediate ISS classifications, restrained patients in the non-flail chest cohort had decreased incidence of pneumothorax, pulmonary contusion, and liver injury (P < 0.001). After adjusting for confounders, restrained patients (versus unrestrained) had decreased odds of pneumothorax (aOR=0.91, P=<0.001) and acute respiratory distress syndrome (aOR=0.65, P=0.02), while having increased odds of splenic laceration (aOR=1.18, P=0.003) (intermediate ISS group). Compared to unrestrained patients, restrained non-flail chest patients had a significantly decreased hospital length of stay (LOS) and intensive care unit LOS (P < 0.05).
Seatbelt use may be protective against serious injuries in patients with ≥2 rib fractures, resulting in improved outcomes. Education programs should be developed to bolster seatbelt compliance.
Seatbelt use may be protective against serious injuries in patients with ≥2 rib fractures, resulting in improved outcomes. Education programs should be developed to bolster seatbelt compliance.Mixed multiple oxidation states CoMoO4 nanowires (electrocatalysts) with tunable intrinsic oxygen vacancies were fabricated. CoMoO4 with proper oxygen vacancy can be employed to construct a Li-air battery with a high capacity and stable cyclability. This is possible because CoMoO4 contains surface oxygen vacancies, which result in the unit of CoMo bond, that is important for electrocatalysts used in Li-air batteries. Both the experimental and theoretical results demonstrate that the surface oxygen vacancies containing CoMoO4 nanowires have a higher electrocatalytic activity. This shows that the highly efficient electrocatalysts used for Li-air batteries were designed to modify the redox properties of the mixed metal oxide in the catalytic active sites. This successful material design led to an improved strategy for high oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activities based on the fast formation and extinction of ORR products.
It is a Holy Grail to realize the goal-oriented synthesis of zeotype crystals via direct thermodynamic/kinetic control of crystallization in the simplest inorganic system. Especially, the most commonly used counter cations (i.e., Na
and K
) are in turn believed to play merely the role of balancing charges and stabilizing frameworks, which make the simple ion-based morphology/porosity control remain big challenges.
We re-examined the role of Na
and K
to fine-tune the classical/nonclassical crystallization process in a seed-induced system with the simplest composition (Si/Al sources, inorganic alkali, and H
O), and proposed an "ion switch" strategy. By analyzing the multiple growth curves, tracking the precursor evolution, and observing epitaxial crystallization behavior, a distinctive "ion switch"-worked nonclassical mechanism was uncovered.
By the "ion switch" strategy, ZSM-5 mesocrystals were fine-regulated with diverse architecture from single crystal to nanocrystallite assembly and intracrystali metal ions from Li+ to Cs+, and ZSM-5 mesocrystals with extended morphologies can be obtained.Controlling the size of nanocrystals and inhibiting their agglomeration are of paramount importance for achieving ideal catalytic performance. Here we discovered that carbon dots (CDs) are not only able to serve as reductants but also as stabilizers of ultrasmall Co9S8 nanocrystals by means of their surface terminal groups. As a result, ultrasmall Co9S8 nanocrystals are incorporated into porous carbon nanosheets formed by splicing CDs. The resultant nanocomposites display a rich pore structure accompanying with large specific surface area and outstanding bifunctional performances to mimic the catalytic activity of peroxidase and oxidase without exerting any external energy. More importantly, the unique architecture endows Co9S8 nanocrystals with high stability and good durability. The nanocomposites have been demonstrated as a colorimetric sensor for detection of ascorbic acid with a superior anti-interference ability as well as a detection limit of 0.2 μM. Our findings open new synthetic opportunities by tuning the interaction of CDs with the surrounding environment and enable advanced applications such as biomedicine and catalytic transformations.