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Stratified rock masses comprise various rocks with different thicknesses, lithologies, and compositions. They exhibit unique cracking morphology and failure modes when subjected to external loads. Understanding and mastering the fracture morphology and failure laws of stratified rock masses under three-dimensional mechanical conditions is crucial for researching disasters in underground engineering geology. This paper presents a three-dimensional double-layer rock mass model established using the numerical calculation method based on mesoscopic statistical damage mechanics. The model simulates the cracking mode of the rock surface under biaxial tensile conditions. The simulation results are quantified using PCAS software. Crack indexes, such as the number of cracked blocks, average cracked block area, and surface crack rate, are used to evaluate the degree of influence of different factors on the cracking of the rock surface layer. The results indicate that the degree of surface crack development varies linearly with the degree of homogeneity (m). Additionally, the layer thickness ratio (η) is positively correlated with the average fragmentation area, and the two are logarithmic. Regardless of the model scale, the average circumference of each block is approximately equal to the model side length. The model exhibits the highest degree of crack development when the loads in the x and y directions are equal. Moreover, the degree of crack development in the model is also influenced by the loading per step, and the two are proportional.

Abstract Here, a novel modular multilevel converter (MMC) and its associated control scheme are proposed for medium‐voltage direct‐current (MVDC) distribution systems. The voltage gain and power can achieve wide‐range expansion by expanding sub‐modules. The voltage, current, and power are shared among all sub‐modules. In addition, all semiconductor devices implement soft switching under low voltage stress and current stress by introducing an auxiliary cell in each sub‐module. By reasonably distributing the energy collected in the soft switching process, the converter realizes the self‐power supply for the drive control circuit of the high‐potential semiconductor switches, wherein the sub‐modules are turned on step by step. The structure of the converter is described and its working principle and control strategy are analyzed in detail. Finally, a 1.8 kW experimental prototype based on SiC devices is provided to achieve an efficiency of 97.3%.

The response of dryland vegetation to climate change is particularly sensitive in the context of global climate change. This paper analyzes the characteristics of spatial and temporal dynamics of vegetation cover in the Tarim River Basin, China, and its driving factors in order to investigate the response of vegetation growth to water storage changes in the basin. The Enhanced Vegetation Index (EVI), the GRACE gravity satellite, and meteorological data from 2002 to 2022 are used to decipher the characteristics of the response of water storage changes to vegetation changes, which is of great significance to the realization of regional ecological development and sustainable development. The results of the study show the following: (1) The vegetation in the Tarim River Basin has an overall increasing trend, which is mainly distributed in the Aksu Basin and the Weigangkuche River Basin and is spatially distributed in the form of a ring. (2) Vegetation distribution greatly improved during the 20-year study period, dominated by high-cover vegetation, with a change rate of 200.36%. Additionally, vegetation changes are centered on the watersheds and expand to the surrounding area, with a clear increase in vegetation in the Kumukuri Basin. Areas with a vegetation Hurst index of

The accelerated urbanization taking place across Xinjiang in recent years has vastly improved the quality of life for people living in the region. However, to achieve rational urban growth and sustainable regional development, a deeper understanding of the spatial and temporal patterns, spatial morphology, and driving factors of urban sprawl is crucial. Nighttime light (NTL) data provide a novel approach for studying the spatial and temporal changes in urban expansion. In this study, based on DMSP-OLS and NPP-VIIRS data, we analyze the spatiotemporal characteristics of urban changes using the standard deviation ellipse and employ the geographical detector to analyze the impact of natural environmental and socioeconomic factors on the dynamic rate of urban expansion. The results reveal the following. (1) The overall accuracy of urban area extraction is above 80%, and the urban area of Xinjiang has expanded about 9.1 times over the past 30 years. Further, the growth rate from 2007 to 2017 exceeds the growth rate from 1992 to 1997, with the center of gravity of urban development shifting to the southwest. (2) The 5a sliding average temperature and average annual precipitation in the study area in 1992–2022 are 6.08 °C and 169.72 mm, respectively, showing a decrease in the urbanization rate followed by an increase, due to a rise in temperature and precipitation levels. (3) By combining the results of geographical detector factor detection and interaction detection, precipitation is determined to be the main controlling factor, while air temperature and GDP are secondary factors. This study presents new findings on the correlation between urban spatial and temporal changes and climate in Xinjiang, thus providing a scientific reference for future research on urban expansion and natural environment evolution.

Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)—the causative agent of coronavirus disease 2019 (COVID-19)—has caused a global public health emergency. Personal protective equipment (PPE) is the primary defence against viral exposure in healthcare and community settings. However, the surfaces of PPE materials may trap virus for contact transmission or through laden aerosols generated during removal of PPE, through cleaning or during movement. In this study, the relative efficacy of current PPE materials in terms of virion adsorption to materials and their antiviral potency, has been evaluated on a wide range of PPE for the first time, including four polymer glove types, two types of scrubs, apron material, a mask, visor and a selection of other commercial polymers and products. Although differences in virion adsorption to the test materials were observed, none of the existing polymer-based PPE resulted in more than tenfold reduction in the SARS-CoV-2 titre within either 10 min or 30 min contact period. The wettability and surface chemistry of the test materials were analysed to investigate any correlations with their surface physicochemical properties. While no correlation was found between wettability and viral retention under air flow challenge, one secondary ion of m/z 101.03 (+) and three secondary ions of m/z 31.98 (−), 196.93 (−) and 394.33 (+) in ToF–SIMS data of the test materials showed positive and negative correlations with the viral retention, respectively, which was identified by PLS regression model, suggesting that the surface chemistry plays a role in determining the extent of virion adsorption. Our findings outline the material aspects that influence the efficacy of current PPE against SARS-CoV-2 transmission and give suggestions on the development of novel simple polymer-based PPE for better infection protection.

Abstract Here, a novel modular bidirectional high voltage gain soft‐switching DC–DC converter is proposed. The proposed converter named gridded modular high‐gain soft‐switching DC–DC converter (GMHSC) can achieve wide range expansion of port voltage and voltage gain by gridded filling of modules and achieve voltage and current sharing among these modules. In addition, all semiconductor devices also realize full‐load soft‐switching operation in both power directions by introducing a simple auxiliary zero‐current transaction (ZCT) cell in each module. A distributed control system including a centre controller and localized module controllers is proposed to improve the converter's design flexibility and dynamic performance. Moreover, the GMHSC is able to provide multiple fixed voltage nodes, which makes it suitable to expend to a multiport converter. A 1.6 kW 200 kHz experimental prototype based on SiC device is provided to achieve an efficiency of 97.9% and 97.7% in boost and buck modes, respectively. Furthermore, the input current and output voltage ripples are greatly reduced through interleaved operation of the GMHSC.

Poly(glycerol monomethacrylate)-block-poly(2-hydroxypropyl methacrylate) (PGMA-PHPMA) with worm-like morphology is a typical example of reversible addition–fragmentation chain transfer (RAFT) dispersion polymerized thermo-responsive copolymer via polymerization-induced self-assembly (PISA) in aqueous solution. Chain transfer agents (CTAs) are the key component in controlling RAFT, the structures of which determine the end functional groups of the polymer chain. It is therefore of interest to monofunctionalize the polymers via CTA moiety, for bioactive functionality conjugation and in the meantime maintain the precisely controlled morphology of the copolymers and the related property. In this work, a newly designed CTA 5-(2-(tert-butoxycarbonylamino) ethylamino)-2-cyano-5-oxopentan-2-yl benzodithioate (t-Boc CPDB) was synthesized and used for the RAFT polymerization of PGMA45-PHPMA120. Subsequently, PGMA45-PHPMA120 copolymers with primary amine, maleimide, and reduced L-glutathione (a tripeptide) monofunctionalized terminals were synthesized via deprotection and conjugation reactions. These monofunctionalized copolymers maintain worm-like morphology and thermo-responsive property in aqueous solution (10% w/v), as confirmed by the transmission electron microscopy (TEM) images, and the observation of the phase transition behavior in between 4 °C and room temperature (~20 °C), respectively. Summarily, a range of thermo-responsive monofunctionalized PGMA45-PHPMA120 diblock copolymer worms were successfully synthesized, which are expected to offer potential biomedical applications, such as in polymer therapeutics, drug delivery, and diagnostics.

Background: To investigate the risk factors for myocardial infarction, recurrent in-stent restenosis (ISR) and target vessel revascularization (TVR) in patients with coronary ISR within 4 years after revascularization. Methods: A total of 1884 patients who were hospitalized at Fuwai Hospital for ISR and successfully treated with coronary intervention between January 2017 and December 2018 were included to determine whether there were myocardial infarction, recurrent ISR, TVR and other major adverse cardiovascular events (MACEs) within 4 years after intervention. The patients were divided into the MACE group (215 patients) and the non-MACE group (1669 patients). The clinical data of patients in the two groups were compared, and the risk factors for postoperative MACEs in the ISR patients were obtained by multivariate logistic regression analysis. The receiver operating characteristic (ROC) curve was used to determine the optimal prediction threshold for postoperative MACEs in ISR patients. The difference in survival curves between the two groups was compared using Kaplan‒Meier survival analysis. Results: The albumin (43.42 ± 4.77 vs. 44.17 ± 4.46, p = 0.021), direct bilirubin (2.5 (2, 3.5) vs. 2.8 (2.07, 3.73), p = 0.036) and free triiodothyronine (FT3) (2.85 ± 0.43 vs. 2.92 ± 0.42, p = 0.019) levels in the MACE group were significantly lower than those in the non-MACE group, and there was a significant negative correlation between albumin and FT3 and MACEs. The results of univariate and multivariate logistic regression analyses revealed that FT3 was an independent predictor of postoperative MACEs in ISR patients (Odds Ratio (OR) = 0.626, 95% CI: 0.429–0.913, p = 0.015). The ROC curve analysis determined that an FT3 value of 2.785 pmol/L was the optimal prediction threshold. According to the threshold, ISR patients were divided into the FT3

Without sacrificing any solution accuracy, an efficient optimization scheme of determining the orientation relationship only based on the daughter phase (i.e., lath martensite in steels in this paper) was established in this work, which involves two key steps. Firstly, an accurate clustering algorithm was developed to perform a statistic of all variants, which can give the most probable orientation and area fraction for each variant. Different from previous methods, the second step is to perform a newly-established optimization scheme, which is able to take variant fractions into consideration to determine the optimal orientation relationship and orientation of prior austenite simultaneously. In this case, the variant-level calculation, which can save much computational time compared with pixel/domain-level calculation, is beneficial for the efficiency promotion. Through inputting the equally-weighted variants into the optimization scheme, the influence of the random cross-sections on the solutions can be effectively eliminated. Furthermore, in-situ high temperature EBSD examinations were first performed to validate solution accuracy, the corresponding results clearly indicated that the orientation of austenite obtained from this approach exhibited a high accuracy and the error is less than 1°.

Upper Critical Solution Temperature (UCST)-type thermally responsive polypeptides (TRPs) with phase transition temperatures around 37 °C in phosphate-buffered saline (PBS) buffer (pH 7.4, 100 mM) were prepared from poly(l-ornithine) hydrobromide and coated on non-tissue culture-treated plastic plates (nTCP). Cell adhesion was observed at temperatures above the phase transition temperature of the coating polymer (39 °C), while cell release was triggered when the culture temperature was switched to 37 °C. Approximately 65% of the attached cells were released from the surface within 6 h after changing the temperature, and more than 96% of the released cells were viable. Water contact angle measurements performed at 39 and 37 °C demonstrated that the surface hydrophobicity of the new TRP coatings changed in response to applied temperature. The cell attachment varied with the presence of serum in the media, suggesting that the TRP coatings mediated cell attachment and release as the underlying polymer surface changed conformation and consequently the display of adsorbed protein. These new TRP coatings provide an additional means to mediate cell attachment for application in cell-based tissue regeneration and therapies.

The epitranscriptomic mark N6-methyladenosine (m6A) is the most common type of messenger RNA (mRNA) post-transcriptional modification in eukaryotes. With the discovery of the demethylase FTO (FAT MASS AND OBESITYASSOCIATED PROTEIN) in Homo Sapiens, this modification has been proven to be dynamically reversible. With technological advances, research on m6A modification in plants also rapidly developed. m6A modification is widely distributed in plants, which is usually enriched near the stop codons and 3'-UTRs, and has conserved modification sequences. The related proteins of m6A modification mainly consist of three components: methyltransferases (writers), demethylases (erasers), and reading proteins (readers). m6A modification mainly regulates the growth and development of plants by modulating the RNA metabolic processes and playing an important role in their responses to environmental signals. In this review, we briefly outline the development of m6A modification detection techniques; comparatively analyze the distribution characteristics of m6A in plants; summarize the methyltransferases, demethylases, and binding proteins related to m6A; elaborate on how m6A modification functions in plant growth, development, and response to environmental signals; and provide a summary and outlook on the research of m6A in plants. [ABSTRACT FROM AUTHOR]

The application of whole-rock compositions to trace magma evolution or crystal-melt equilibrium may be called into question when foreign crystals are incorporated into host magmas. To address this challenge, establishing the origins (orthocrysts, antecrysts, xenocrysts, etc.) of minerals with variable textures in magmatic plumbing systems is necessary. In this paper, we describe complex oscillatory zoning patterns of clinopyroxenes (Cpx) from the Miocene Majuangou (MJG) alkali basalts from West Qinling, China. Our detailed petrographic, mineralogical, and geochemical analyses unravel the origins of various Cpx crystals with distinct textural patterns, thereby providing information about magma storage, recharging and/or mixing, and transportation, as well as the reactions between crystals and melts/fluids. Based on textural patterns, Cpx may be divided into four types: normal (Type-1 Cpx), simple oscillatory (Type-2 Cpx), complex oscillatory (Type-3 Cpx), and grains that lack zoning (Type-4 Cpx, suggested to be orthocrysts). Through the textural characterization of Cpx, the comparison between different types of Cpx, and the relationships between Cpx major compositions from different lithologies, we concluded that Type-1–3 Cpx cores are antecrysts or xenocrysts with diverse origins: primitive magma (Type-1 Cpx cores), magma mush (Type-2 Cpx cores), and crustal granulite (Type-3 Cpx cores). The zoning patterns and the compositions of these Cpx crystals indicate at least three batches of magmatic activity, i.e., the Batch-1 low-Mg# magma (Mg#: 47.4–53.3), the Batch-2 primitive magma (Mg#: 57.2–64.5), and the Batch-3 low-Mg# host alkali magma (Mg#: 47.2–54.6). Cpx-melt thermobarometry demonstrates that at least two crustal magma reservoirs existed in the magma plumbing system at depths of 30.1 and 40.9 km. The antecrystic/xenocrystic Cpx cores were captured by, continued to grow in, and subsequently reacted with ascending K-rich melt/fluid. The spongy textures in Cpx cores/mantles are attributed to this reaction, which may be expressed as: Melt 1 (primitive or evolved) + K-rich melts/fluids + Cpx (CaMgSi2O6) = K-feldspar (KAlSi3O8) + ilmenite (FeTiO3) + Melt 2 (derivative). The products of this reaction (K-feldspar and ilmenite) filled the sieves in the spongy zones of Type-1–3 Cpx. This detailed investigation of compositional and textural features of Cpx antecrysts/xenocrysts suggests that the interactions between various interconnected magma reservoirs are widespread beneath the magmatic plumbing system. Our study emphasizes the importance of the incorporation of foreign crystals and the Cpx-melt/fluid reaction in magmatic plumbing system, which can significantly modify the whole-rock compositions and lead to the formation of spongy textures without the need for fractures and cracks in minerals. [ABSTRACT FROM AUTHOR]