Evaluation of the Goss-modified solvation parameter model for the characterization of biphasic systems and descriptor assignments.

The solvation parameter model uses six descriptors identified as excess molar refraction, E, dipolarity/polarizability, S, overall hydrogen-bond acidity, A, overall hydrogen-bond basicity, B, McGowan's characteristic volume, V, and the gas-liquid partition constant on hexadecane at 25 °C, L to model the distribution of neutral compounds in biphasic systems. Abraham's version of this model uses all six descriptors with two separate linear free energy relationship models for the transfer of compounds from a gas phase to a condensed phase and between condensed phases. Goss proposed a modification to this model that uses a single calibration model regardless of the physical state for each phase and five of the descriptors employed in Abraham's model (E descriptor is eliminated). The capability of Abraham's model and the Goss-modified model to characterize the contribution of intermolecular interaction to retention for gas and reversed-phase liquid chromatographic systems and distribution in liquid-liquid partition systems is evaluated using the WSU compound descriptor database. These more accurate values for the Abraham descriptors have not been utilized previously for the evaluation of the Goss-modified model and should be more capable of discerning subtle differences in model performance. It is shown that model quality defined by statistical parameters favors Abraham's model over the Goss-modified model with differences in model quality greater for systems in which Abraham's model indicates a significant contribution from electron lone pair interactions and for systems in which one phase is a solvent containing perfluoroalkyl substituents. There is a small systematic difference for the terms describing the combined contributions of cavity formation and dispersion interactions and for interactions of a dipole-type. The contribution of hydrogen-bonding interactions is virtually identical for the two models. The model intercepts are generally different and potentially assigned to a larger contribution from lack-of-fit for the Goss-modified model. Although the Abraham model descriptors have been routinely employed for applications using the Goss-modified model the possibility that Goss-model specific descriptors should be employed was evaluated. Using the Solver method and Goss-model specific calibration models for chromatographic and liquid-liquid partition systems a new set of Goss-specific descriptors was calculated for 28 varied compounds. These descriptors show good statistical agreement with the Abraham descriptor values with an average deviation of 0.009, -0.003, -0.004, and -0.023, respectively, for the S, A, B, and L descriptors, corresponding to a relative absolute deviation in percent of 2.2 %, 3.9 %, 4.3 %, and 1.2 %, respectively.

Logistics and distribution of small extracellular vesicles from the subcutaneous space to the lymphatic system.

Small extracellular vesicles (sEVs) are small, cell-derived particles with sizes of approximately 100 nm. Since these particles include cargos such as host cell-derived proteins, messenger RNAs, and micro RNAs, they serve as mediators of cell-cell communication. While the analysis of the pharmacokinetic of sEVs after the intravenous injection have been reported, the lymphatic transport of sEVs remains unclear. The objective of this study was to provide insights into the intra-lymphatic trafficking and distribution of sEVs when they are injected into an interstitial space both in normal skin tissue and in cancerous tissue. When sEVs were Subcutaneously administered into the tail base and the tumor tissue, they preferably accumulated in the lymph nodes (LNs), rather than in the liver and the spleen. The findings reported herein show that the lymphatic transport of sEVs was drastically changed in model mice, in which a surgical treatment was used to modify to allow the dominant lymphatic flow from the footpad directly to the axillary LN via the inguinal LN. Based on the results, we conclude that when sEVs are injected into the subcutis space, they are preferably delivered to the LN via the lymphatic system. Further, the extent of accumulation of sEVs in the LN after subcutaneous injection was reduced when they were preliminarily incubated with Proteinase K. These results suggest that the lymphatic drainage of sEVs in normal skin tissue is regulated by membrane proteins on their surface. This reduction, however, was not observed in the case of cancer tissue. This discrepancy can be attributed to the presence of highly permeable lymphatic vessels in the tumor tissue. Further, the major cell subtypes that captured sEVs in the LN were LN-resident medullary sinus macrophages. These collective findings indicate that the lymphatic drainage of sEVs are mediated by proteins and, that they may appear to contribute to the control of the function of immune-responsive cells in the LNs.

Oxidative Stress Markers and Modified Model for End-Stage Liver Disease Are Associated with Outcomes in Patients with Advanced Heart Failure Receiving Bridged Therapy with Continuous-Flow Left Ventricular Assist Devices.

Left ventricular assist device (LVAD) is well established as an alternative treatment for end-stage heart failure (HF) patients. The aim of the study was to determine the prognostic value of oxidative stress markers and the modified Model for End-Stage Liver Disease (modMELD) in patients receiving bridged therapy with continuous-flow LVAD. We prospectively analyzed 36 end-stage HF patients who received LVAD therapy between 2015 and 2018. The total antioxidant capacity (TAC) and total oxidant status (TOS) were measured by the methods described by Erel. The oxidative stress index (OSI) was defined as the ratio of the TOS to TAC levels. The modMELD scores were calculated based on the serum bilirubin, creatinine, and albumin levels. The patients' median age was 58 (50-63.0) years. During the 1.5-years follow-up, a major adverse cardiac event-MACE (death, stroke, or pump thrombosis) was observed in 17 patients (47.2%). The area under the receiver operating characteristics curves (AUCs) indicated a good prognostic power of TAC (AUC 0.7183 (0.5417-0.8948)), TOS (AUC 0.9149 (0.8205-0.9298)), OSI (AUC 0.9628 (0.9030-0.9821)), and modMELD (AUC 0.87 (0.7494-0.9905)) to predict a MACE. Oxidative stress markers serum concentrations, as well as the modMELD score, allow the identification of patients with a risk of MACE.

Prediction of sulfamerazine and sulfamethazine solubility in some cosolvent mixtures using non-ideal solution models / Predicción de la solubilidad de sulfamerazina y sulfametazina en algunas mezclas cosolventes utilizando modelos de solución no ideales / Predição da solubilidade de sulfamerazina e sulfametazina em algumas misturas de cosolventes usando modelos de solução não ideais

SUMMARY Introduction: Experimental Solubilities of sulfamerazine (SMR) and sulfamethazine (SMT) in some (methanol + water), (ethanol + water) and (1-propanol + water) cosolvent mixtures were collected from the literature at five temperatures from 293.15 to 313.15 K. Methodology: The results were analyzed with the van't Hoff, Apelblat modified, Buchowski-Ksiazaczak λh, van't Hoff-Yaws model, two-parameter Weibull function model. It was determined that the models that best describe the solubility of these sulfonamides in (alcohol + water) mixtures were the van't Hoff and Apelblat models, obtaining correlation indices greater than 0.99 in all cases. Results: The results obtained with the Modified Apelblat equation presents a high correlation index for the solubility of SMR and SMT in cosolvent mixtures, followed by the van't Hoff-Yaws model that presents a high fit of the estimated data with respect to the theoretical ones. According to the two-parameter Weibull function model, the solubility ofSMR and SMT in the co-solvent mixtures shows important deviations from ideality, which is consistent with the literature. The results are discussed in terms of the solute-solvent interactions that occur in this system.

RESUMEN Introducción: Las solubilidades experimentales de la sulfamerazina (SMR) y la sulfametazina (SMT) en algunas mezclas cosolvents (metanol + agua), (etanol + agua) y (1-propanol + agua), se revisaron en la literatura a cinco temperaturas de 293,15 a 313,15 K. Metodología: Los resultados se analizaron con el modelo van't Hoff, Apelblat modificado, Buchowski-Ksiazaczak λh, van't Hoff-Yaws, y el modelo de la función Weibull de dos parámetros. Se determinó que los modelos que mejor describen la solubilidad de estas sulfonamidas en mezclas (alcohol + agua) son los modelos de van't Hoffy Apelblat, obteniendo índices de correlación superiores a 0,99 en todos los casos. Resultados: Los resultados obtenidos con la ecuación de Apelblat modiicada presentan un alto índice de correlación para la solubilidad de SMR y SMT en mezclas de cosolventes, seguido del modelo van't Hoff-Yaws que presenta un alto ajuste de los datos calculados con respecto a los teóricos. Según el modelo de la función de Weibull de dos parámetros, la solubilidad de la SMR y la SMT en las mezclas de cosolventes muestra importantes desviaciones de las ideales, lo que es coherente con la literatura. Los resultados se discuten en términos de las interacciones soluto-solvente que se producen en este sistema.

RESUMO Introdução: As solubilidades experimentais de sulfamerazina (SMR e sulfametazina (SMT) em algumas misturas de cossolventes (metanol + água), (etanol + água) e (1-propanol + água), foram revisadas na literatura em cinco temperaturas de 293,15 a 313,15 K. Metodologia: Os resultados foram analisados com o modelo van't Hoff, Apelblat modificado, Buchowski-Ksiazaczak λh, van't Hoff-Yaws e o modelo de função Weibull de dois parâmetros. Determinou-se que os modelos que melhor descrevem a solubilidade dessas sulfonamidas em misturas (álcool + água) são os modelos van't Hoff e Apelblat, obtendo índices de correlação superiores a 0,99 em todos os casos. Resultados: Os resultados obtidos com a equação de Apelblat modi-icada apresentam um alto índice de correlação para a solubilidade de SMR e SMT em misturas de cosolventes, seguido pelo modelo de van't Hoff-Yaws que apresenta um alto ajuste dos dados calculados em relação a teóricos. De acordo com o modelo de função Weibull de dois parâmetros, a solubilidade de SMR e SMT em misturas de cosolventes apresenta desvios signiicativos dos ideais, o que é consistente com a literatura. Os resultados são discutidos em termos das interações soluto-solvente que ocorrem neste sistema.

Learning curve and key procedures analysis of modified rat models of orthotopic left lung transplantation / 器官移植

Objective To summarize and analyze the key procedures of the modified rat model of orthotopic left lung transplantation, aiming to provide more experience for the establishment of rat models of lung transplantation. Methods Two surgeons (A and B) performed complete transplantation in consecutive 15 rat models, and every 5 surgeries were divided into 1 practice stage. The operating time of each transplantation procedure was recorded. The differences of overall success rate and 1-week survival rate were calculated among different practice stages. The learning curve was delineated by the cumulative sum method. Results For surgeons A and B, the number of the first successful transplantation was the 5th and 6th time, the overall success rates of transplantation were 80% and 87% respectively, and the 1-week survival rates of rats both were 92%. Along with the increasing number of surgeries, the entire cardiopulmonary procurement, cannula preparation, cold ischemia, warm ischemia, transplantation and total operation time by two surgeons showed a significantly downward trend (all P < 0.05). For surgeons A and B, 3 and 2 rats died of heart failure due to overdose anesthesia, and 1 rat died of vein distortion at postoperative 1 d and 1 died of atelectasis at postoperative 7 d, respectively. The goodness of fit (R2) of cumulative sum method was 0.992 8 and 0.976 6. The turning point of learning curve was achieved in the 7th and 8th transplantation for surgeons A and B. Conclusions The modified rat model of orthotopic left lung transplantation yields high operability and repeatability both theoretically and technologically, and has multiple advantages of short learning curve, short operation time, high survival rate of the recipients and few complications, which is worthy of application in the basic research of lung transplantation.

Influence of Thermally-Accelerated Aging on the Dynamic Mechanical Properties of HTPB Coating and Crosslinking Density-Modified Model for the Payne Effect.

Hydroxyl terminated polybutadiene (HTPB) coating is widely used in a solid rocket motor, but an aging phenomenon exists during long-term storage, which causes irreversible damage to the performance of this HTPB coating. In order to study the effect of aging on the dynamic mechanical properties of the HTPB coating, the thermally-accelerated aging test was carried out. The variation of maximum elongation and crosslinking density with aging time was obtained, and a good linear relationship between maximum elongation and crosslinking density was found by correlation analysis. The changing regularity of dynamic mechanical properties with aging time was analyzed. It was found that with the increase of aging time, Tg of HTPB coating increased, Tα, tan ß and tan α decreased, and the functional relationships between the loss factor parameters and crosslinking density were constructed. The storage modulus and loss modulus of HTPB coating increased with the increase of aging time, and decreased with the increase of pre-strain. The aging enhanced the Payne effect of HTPB coating, while the pre-strain had a weakening effect. In view of the Payne effect of HTPB coating, the crosslinking density was introduced into Kraus model as aging evaluation parameter, and the crosslinking density modified models with and without pre-strain were established. The proposed models can effectively solve the problem that the Kraus model has a poor fitting effect under the condition of small strain (generally less than 1%) and on the loss modulus, which have improved the correlations between the fitting results and the test results.

Automatic Extraction of Offshore Platforms in Single SAR Images Based on a Dual-Step-Modified Model.

The quantity and location of offshore platforms are of great significance for marine oil spill monitoring and offshore oil-gas development. In the past, multiphase medium- and low-resolution optical or radar images have been used to remove the interference of ship targets based on the static position of a platform to extract the offshore platform, resulting in large demands and high image data costs. According to the difference in shape between offshore platforms (not elongated) and ships (elongated shapes) in SAR (synthetic aperture radar) images, this paper proposes an automatic extraction method for offshore platforms in single SAR images based on a dual-step-modified model. First, the two-parameter CFAR (constant false alarm rate) algorithm was used to detect the possible offshore platform targets; then, the Hough transform was introduced to detect and eliminate ship targets with linear structures. Finally, the final offshore platform was obtained. Experiments were carried out in four study areas in the Beibu Gulf basin and the Pearl River estuary basin in the northern South China Sea. The results show that the method has a good extraction effect in the above research area, and the extraction accuracy rate of offshore platforms is 86.75%. A single SAR image can obtain satisfactory extraction results, which greatly saves on image data cost.