Zobrazení zdroje stránky Kjerwollesen6693

In many applications of two-component mixture models such as the popular zero-inflated model for discrete-valued data, it is customary for the data analyst to evaluate the inherent heterogeneity in view of observed data. To this end, the score test, acclaimed for its simplicity, is routinely performed. It has long been recognized that this test may behave erratically under model misspecification, but the implications of this behavior remain poorly understood for popular two-component mixture models. For the special case of zero-inflated count models, we use data simulations and theoretical arguments to evaluate this behavior and discuss its implications in settings where the working model is restrictive with regard to the true data generating mechanism. We enrich this discussion with an analysis of count data in HIV research, where a one-component model is shown to fit the data reasonably well despite apparent extra zeros. These results suggest that a rejection of homogeneity does not imply that the underlying mixture model is appropriate. Rather, such a rejection simply implies that the mixture model should be carefully interpreted in the light of potential model misspecifications, and further evaluated against other competing models.In this minireview we present the use of the axially chiral 1,1'-binaphthyl-2,2'-diol (BINOL) unit as a stereogenic element in mechanically interlocked molecules (MIMs). We describe the synthesis and properties of such BINOL-based chiral MIMs, together with their use in further diastereoselective modifications, their application in asymmetric catalysis, and their use in stereoselective chemosensing. Given the growing importance of mechanically interlocked molecules and the key advantages of the privileged chiral BINOL backbone, we believe that this research area will continue to grow and deliver many useful applications in the future.The interest in organic materials exhibiting thermally activated delayed fluorescence (TADF) significantly increased in recent years owing to their potential application as emitters in highly efficient organic light emitting diodes (OLEDs). Simple modification of the molecular structure of TADF compounds through the selection of different electron-donating or accepting fragments opens great possibilities to tune the emission properties and rates. Here we present the synthesis of a series of novel pyrimidine-carbazole emitters and their photophysical characterization in view of effects of substituents in the pyrimidine ring on their TADF properties. We demonstrate that electron-withdrawing substituents directly connected to the pyrimidine unit have greater impact on the lowering of the energy gap between singlet and triplet states (ΔE ST) for efficient TADF as compared to those attached through a phenylene bridge. A modification of the pyrimidine unit with CN, SCH3, and SO2CH3 functional groups at position 2 is shown to enhance the emission yield up to 0.5 with pronounced TADF activity.A series of tetraamino-bisthiourea chiral macrocycles containing two diarylthiourea and two chiral diamine units were synthesized by a fragment-coupling approach in high yields. Different chiral diamine units, including cyclohexanediamines and diphenylethanediamines were readily incorporated by both homo and hetero [1 + 1] macrocyclic condensation of bisamine and bisisothiocyanate fragments. With the easy synthesis, gram-scale of macrocycle products can be readily obtained. These chiral macrocycles were applied in catalyzing bioinspired decarboxylative Mannich reactions. Only 5 mol % of the optimal macrocycle catalyst efficiently catalyzed the decarboxylative addition of a broad scope of malonic acid half thioesters to isatin-derived ketimines with excellent yields and good enantioselectivity. [https://www.selleckchem.com/products/sm-164.html SM-164 in vivo] The rigid macrocyclic framework and the cooperation between the thiourea and tertiary amine sites were found to be crucial for achieving efficient activation and stereocontrol. As shown in control experiments, catalysis with the acyclic analogues having the same structural motifs were non-selective.The motivation of this study was to investigate the feasibility of production of green and sustainable bitumen modified with waste styrofoam (WS) that contributed to the base bitumen in certain rate. To achieve it, not only basic but also rheological properties and storage stability of WS-modified bitumen were taken into consideration. In this respect, bitumen with 70/100 penetration grade was modified with WS in different rates ranging from 1 to 5% with 1% increment. Basic test methods including penetration, softening point, rotational viscometer were conducted on the bitumen samples to analyze physical properties, while dynamic shear rheometer and bending beam rheometer tests were performed on the samples for rheological assessment. Rolling thin film oven and pressure aging vessel tests, which are aging methods in rheological evaluation, were followed to supply short- and long-term aged samples, respectively. Storage stability test was conducted on the modified samples to determine the compatibility between the two materials at different contribution WS rates. The results showed that significant changes occur on both physical and rheological properties of WS-modified bitumen. Compatibility between WS and bitumen was not observed except of the bitumen modified up to 2% WS as examined with softening point, but up to 3% WS as examined with penetration test. Overall, disposal of WS within bitumen modification can be a green and sustainable as considering the ecological and economic aspects.Functional cotton fabrics using silver-based nanoparticles (AgNPs) have attracted a lot of attention as a new generation of healthcare wearable textile. In this study, cotton fabrics were coated via impregnation with silver nanoparticles using chitosan (Cs) and (or) chitosan-organosilica (Cs-OSH) solutions as adhesives matrices. The physicochemical properties were studied using UV-VIS spectroscopy, and transmission electron microscopy (TEM) and scanning electron microscope coupled with energy-dispersive X-ray spectroscopy methods (SEM-EDX). The antibacterial activity of the silver-treated fabrics was determined using agar diffusion method. However, nanosize spherical AgNPs were observed in Cs and Cs-OSH solution. The average particle diameter was around 10 nm for Cs/AgNPs sample and close 21 nm for Cs-OSH/AgNPs. Microscopy images showed the deposition of Ag NPs on the surface of cotton fibers. The results indicated that the cotton fibers treated with Cs-OSH/AgNPs solution showed good stability against washing and maintained higher antimicrobial activity even after being exposed to 10 consecutive home laundering conditions. Thus, this work suggests the use of chitosan-organosilicon matrix to improve the bonding between AgNPs and cotton fibers for better and long-term antimicrobial activity.An 18-year-old boy presented with a giant midline mass with 9 years of evolution. The tumor was excised, and reconstruction made with a customized sternum implant and a free latissimus dorsi muscle flap with skin graft. Histological analysis was compatible with low-grade fibromyxoid sarcoma (LGFMS).In this study, we report three cases wherein reverse lateral upper arm flaps were used to treat very large tissue defects extending from the elbow to the forearm. The flap sizes were 19 × 6.5 cm, 20 × 7 cm, and 17 × 7 cm. All flaps survived and elbow motion recovered sufficiently.Two cases are presented that demonstrate normal wound healing following bilateral reduction mammoplasty, in young female patients taking therapeutic doses of Isotretinoin (Roaccutane). Review of the literature does not provide evidence that Isotretinoin impairs would healing, nor that it promotes hypertrophic or keloid scarring in surgical patients.We report the case of a patient who underwent transcatheter aortic valve implantation via left anterior mini-thoracotomy in whom a periapical subcutaneous collection appeared in the anterior thoracic wall 18 months after the procedure. The tissue defect was efficaciously repaired via intercostal artery perforator flap, preserving the thoracodorsal and internal mammary arteries.Patients with acquired or congenital hemophilia are at risk for Acute Compartment Syndrome (ACS) and pose a diagnostic challenge and a treatment risk with post-fasciotomy hemostasis of critical importance. We present the case of a woman with ACS of the forearm in the setting of newly diagnosed acquired hemophilia A.<br /><br /> Understanding the impact of stressors on the rating of perceived exertion (RPE) is relevant from a performance and exercise adherence/participation standpoint. Athletes and recreationally active individuals dehydrate during exercise. No attempt has been made to systematically determine the impact of exercise-induced dehydration (EID) on RPE.<br /><br /> The present meta-analysis aimed to determine the effect of EID on RPE during endurance exercise and examine the moderating effect of potential confounders.<br /><br /> Performed on raw RPE values using random-effects models weighted mean effect summaries and meta-regressions with robust standard errors, and with a practical meaningful effect set at 1 point difference between euhydration (EUH) and EID. Only controlled crossover studies measuring RPE with a Borg scale in healthy adults performing ≥30min of continuous endurance exercise while dehydrating or drinking to maintain EUH were included.<br /><br /> Sixteen studies were included, representing 147 individuals. Mean body mass loss with EUH was 0.5±0.4%, compared to 2.3±0.5% with EID (range 1.7-3.1%). Within an EID of 0.5-3% body mass, a maximum difference in RPE of 0.81 points (95% CI 0.36-1.27) was observed between conditions. A meta-regression revealed that RPE increases by 0.21 points for each 1% increase in EID (95% CI 0.12-0.31). Humidity, ambient temperature and aerobic capacity did not alter the relationship between EID and RPE.<br /><br /> Therefore, the effect of EID on RPE is unlikely to be practically meaningful until a body mass loss of at least 3%.<br /><br />Therefore, the effect of EID on RPE is unlikely to be practically meaningful until a body mass loss of at least 3%.<br /><br /> Folate receptor alpha (FRα) is overexpressed in various cancer entities while expression in normal tissue is limited. Thus, FRα is an attractive target in cancer therapy. Currently, various therapeutic and diagnostic approaches are under investigation in clinical trials. The aim of this study was to assess the expression and clinical relevance of FRα in adenoid cystic carcinoma of the head and neck.<br /><br /> In this retrospective cohort study, 43 patients with adenoid cystic carcinoma (ACC) of the head and neck were included. FRα expression was analyzed in tumor tissue and tumor-free margin in a tissue microarray using immunohistochemical staining. Protein levels were correlated with clinical parameters.<br /><br /> FRα staining was positive in 47% of ACC patients. The tumor-free margin was positive in 22%. Patients with positive tumor tissue showed positive margin staining in 55%. FRα expression was not associated with the clinical parameters (sex, age, staging, grading, perineural invasion, lymphovascular invasion).<br /><br /> FRα expression is common in ACC of the head and neck.