关键词： Microstructure characterisation   Microstructure reconstruction   Pore structure   BSE image   Image analysis  

摘要： The porous structure of hydrated cement has a significant effect on its governing properties, such as strength, density, ion-diffusion, acoustic performance etc. However, direct observation of the 3D pore structure is limited by high stochasticity and multiscale features. We constructed a statistically equivalent 3D micropore structure using a digital concrete model that used a probabilistic map derived from 2D cross-sections and parameter sets calibrated via a deep learning neural network. Based on the replica of cement pore structure, image analyses and virtual mercury intrusion porosimetry (MIP) tests were compared with experimental outcomes. In particular, the pore size distribution curves matched well for both MIP and image analysis approaches. However, although the fractal dimension derived from each 2D image linearly correlated with the corresponding porosity, it tended to underestimate the complexity of the pore structure. Correspondingly, the 3D fractal dimension showed a periodic pattern to voxel size in log-scale and was slightly higher than the MIP results. The tortuosity factor also had a linear correlation to voxel size, resulting in an overestimation of the pore structure's tortuosity. We demonstrated that the digital concrete model could serve as an alternative approach to studying the microstructural pore analysis of cementitious material through such a comparison. This study's outcome helps to understand the structure-property link in cement with the potential to transform traditional analytical processes of cementitious materials.

摘要： Epstein-Barr virus (EBV) is a human herpesvirus associated with human cancers worldwide. Ex vivo, the virus efficiently infects resting human B lymphocytes and induces their continuous proliferation. This process is accompanied by a global reprogramming of cellular gene transcription. However, very little is known on the impact of EBV infection on the regulation of alternative splicing, a pivotal mechanism that plays an essential role in cell fate determination and is often deregulated in cancer. In this study, we have developed a systematic time-resolved analysis of cellular mRNA splice variant expression during EBV infection of resting B lymphocytes. Our results reveal that major modifications of alternative splice variant expression appear as early as day 1 post-infection and suggest that splicing regulation provides-besides transcription-an additional mechanism of gene expression regulation at the onset of B cell activation and proliferation. We also report a role for the viral proteins, EBNA2 and EBNA-LP, in the modulation of specific alternative splicing events and reveal a previously unknown function for EBNA-LP-together with the RBM4 splicing factor-in the alternative splicing regulation of two important modulators of cell proliferation and apoptosis respectively, NUMB and BCL-X.

关键词： 小学体育   学科整合   有效策略  

摘要： 学科整合是指通过知识之间的相互联系把不同类型的学科进行整合,是指不同学科彼此有相互的关联性.教师在课堂教学中，要制作出合理的教学方案帮助学生学习积极性提升和对文化素养提供的同时，并且也要关注对其他方面的提高,比如包括社会适应整体能力和身体健康。

关键词： Ball milling  

摘要： Vanadium-substituted phosphomolybdic acids (H3+x[PMo12-xVxO40], denoted as V-x) are well-known oxidation catalysts that are generally prepared by the hydrothermal treatment of MoO3 and V2O5 in the presence of H3PO4. This synthesis procedure is highly energy consuming and the V-x yields are not always acceptable. In the present work, an alternative hybrid mechanochemical/hydrothermal synthesis of V-x is proposed, comprising the ball-milling of MoO3 and V2O5, followed by a hydrothermal attack. The resulting materials, with 2 <= x <= 3, obtained from this new route were compared, in terms of yield, energy consumption and catalytic activity, with a reference V-3 sample prepared through a conventional hydrothermal treatment. The ball-milling step proved to lead not only to a shorter and far more energy-saving synthesis procedure, but also to high yields of V-x. Moreover, V-x from this alternative route proved to be generally more active than the conventionally prepared V-3 in the aerobic oxidative cleavage of C-O and C-C bonds in 2-phenoxyacetophenone, used herein as a lignin model compound.

关键词： Acylation   C-H activation   Transition-metals   Metal-free   Photocatalysis  

摘要： Functionalizing and derivatising organic molecules is a centerpiece in organic synthesis. Succinctly manipulating and installing acyl moieties in organic molecules spurred the interest of chemists owing to its occurrence in natural products, bioactive molecules, pharmaceuticals, and advanced materials. Traditionally, access to acylation reaction was achieved by Friedel-Crafts reaction, Schotten-Baumann, and Vilsmeier-Haack acylation, however, these protocols own pitfalls. Further to make the acylation process attractive and environmentally friendly, toluene, aldehydes, alcohols, alpha-keto acids, amines, amides, esters, ethers, nitriles, alkynes, alkenes, ketenes, N-acylbenzotriazoles, ketones, thioacids, oximes, thiazolium carbinols, PIDA, diacyl disulfides and acyl salts were used as an acyl surrogates/reagents. Amusingly, these acylating reagents are considered uncommon and alternative to carboxylic acids, acid chlorides and acetic anhydrides. This short review aims to encompass the usage of acylating agents in transition-metal, metal-free, light-driven and other demanding conditions, and thus reveals their practicality.

关键词： Acetaminophen overdose   acetylcysteine regimen   toxicology   hepatotoxicity   drug safety  

摘要： Introduction Acetylcysteine is the standard treatment for preventing hepatotoxicity caused by acetaminophen overdose. Several novel approaches to the management of acetaminophen overdose have been suggested to improve patient safety by reducing adverse drug reactions and dosing errors. This article reviews these alternative treatment regimens and intends to offer a detailed assessment of the available options to assist providers in managing cases of acetaminophen overdose. Areas covered This review article covers observational and experimental studies that assessed the efficacy and safety of alternative intravenous acetylcysteine regimens for acetaminophen overdose. A literature search was conducted using PubMed, ProQuest, and Scopus to identify the studies, which included results through April 2021. The assessment of alternative regimens consists of a discussion on the limitations and benefits, barriers to implementation, and important considerations for each regimen. Expert opinion Several alternative regimens have been studied and implemented in various institutions. Many of these dosing regimens have supporting safety data but most lack robust data. A reduction in infusion-related side effects is an important outcome, but established efficacy, local poison center familiarity with the regimen, institutional resources, and patient-specific factors should be equally considered when deciding on implementing and using an alternative dosing strategy.

关键词： Augmentative and alternative communication (AAC)   survey   demographics   service delivery   Saudi Arabia  

摘要： Purpose: To develop and distribute a survey to obtain information on the awareness, accessibility and funding for augmentative and alternative communication (AAC) services and devices within the Kingdom of Saudi Arabia (KSA). Method: The survey targeted three groups of people which included individuals with disabilities and their families, healthcare providers such as medical doctors and nurses and the third group included community members. Survey preparation and administration were performed online via a survey website in order to access a wide range of participants across KSA. Results: Results revealed different awareness levels for AAC among the three groups (chi(2) = 45.053, p < .001) with healthcare providers showing a higher degree of awareness compared to the remaining two groups. Moreover, AAC services and devices were found to be accessible within KSA, with no differences in obtaining AAC services and devices among different regions (chi(2) = 14.204, p = .164). Conclusion: Although numerous AAC users were able to obtain AAC devices, they identified barriers including a lack of sufficient awareness of the importance, associated expenses, funding constraints and a lack of Arabization of AAC devices. IMPLICATIONS FOR REHABILITATION Augmentative and alternative communication (AAC) methods allow individuals with communication difficulties to interact and socialize with those around them. The general authority of statistics in Saudi Arabia has shown that Saudi Arabia has an increased number of individuals suffering from severe to extreme communication disorders compared to other countries around the world. Consequently, the need for AAC in Saudi Arabia cannot be underestimated. This study demonstrates the importance of the awareness of AAC among different stakeholders in Saudi Arabia including AAC users, healthcare providers and community members so that individuals with communication problems can receive maximum benefit from AAC. Given that most healthcare prov

关键词： Blow tank   energy efficiency   pneumatic conveying   pressure vessel   solids feeder  

摘要： This work presents the experimental characterization of a novel industrial bulk solids feeder, named Batchpump, and aims to validate the performance in terms of transport capacity and compressed gas consumption of an unconventional compact pressure vessel, used as a feeding device for dense phase pneumatic conveying. Experimental test data was collected for limestone as the conveyed material. The developed device was shown to have similar performance parameters (transport rate and gas consumption) when compared to conventional versions of blow tanks operating at 4 bar pressure and conveying powder material at about 9 t/h rate, albeit the smaller dimensions and simplification in operation, resulting in significative advantages in retrofits and in the implement a new conveyor line.

关键词： Clay   EnergyPlus   hemp   lime   sustainability   thermal simulation  

摘要： This research aims to estimate the operational energy (OE) savings of a full-scale building, made of lime hemp concrete (LHC) with alternative binders partly replacing lime, compared to buildings made of conventional materials, e.g. Autoclaved Aerated Concrete (AAC), Hollow Concrete Blocks (HCB), and Expanded Polystyrene (ESP). The thermal performance of small size (1 m x 1 m) different materials test cells was experimentally studied. Experimental results were compared to simulated values obtained by EnergyPlus. Monitored and simulated indoor temperatures were found to be in good agreement. Subsequently, the thermal performance and energy consumption of full-scale buildings (10 m x 10 m x 2.9 m) were simulated by EnergyPlus with a great degree of confidence. In up-scaled building simulations, LHC presented the best thermal performance and consequently the lowest energy consumption, reaching similar to 7 kWh/m(2)/year, nearly Zero Energy Building standards, 90% lower as compared to HCB which obtained the highest energy consumption. Dynamic external window shading was shown to have a significant impact on cooling energy savings. This research clearly shows the high potential of using LHC with alternative binders as a partial replacement for lime, as it has advantages in terms of energy savings, and their equivalent CO2 emissions.

关键词： Estimand   Information-anchoring   Missing data   Multiple imputation   Pattern-mixture model   Sensitivity analysis  

摘要： Reference-based controlled imputations have become a popular tool to assess the sensitivity of primary analysis inference to different post-dropout assumptions and to yield an alternative effectiveness estimand of treatment effect. As the imputation and analysis models are uncongenial in this setting, Rubin's variance estimator overestimates the repeated sampling variability of the multiple imputation estimator of treatment effect. On the other hand, since reference-based methods borrow information across arms, the sampling variance of treatment effect estimator decreases as the proportion of missing data increases, rendering it inappropriate for use in sensitivity analysis. We propose to decouple the variance estimation from information borrowing by using a delta-adjusted pattern mixture model with delta-adjustments fixed at the maximum likelihood estimate. Reference-based pattern-mixture models can thus be embedded in the sensitivity analysis using delta-adjusted pattern-mixture models by identifying a scalar sensitivity parameter value to match the treatment effect estimate. We provide both theoretical and empirical justifications of the proposed approach and illustrate its use in the analysis of a clinical trial of major depressive disorder.