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The three‐dimensional flow velocities within the typical pool chamber of the rectangular fishway were measured in a vertical slit bottom‐hole combination fishway by a hydraulic model test using an acoustic Doppler velocimeter (ADV). This was aimed to analyze the effect of eddy structures within the pool chamber of the fishway on fish migration. Based on this, a numerical simulation study was conducted using the Reynolds mean model (RNG k‐ε) and large eddy simulation (LES). Additionally, the omega (Ω) eddy identification method was used to identify the eddy structure within the pool chamber of the fishway and dissect the flow characteristics of the water body within the pool chamber. The findings revealed that longitudinal flow velocity dominated the flow in the lower bottom layer of the pond. Moreover, the flow in the middle and upper layers was more turbulent and there is a phenomenon of backflow upstream, and the flow at the orifice was a divergent jet with the main flow slightly to the right bank, forming two vortices in opposite directions on both sides of the orifice. The fish passage mainly displayed the turbulent vortex structure, which can effectively slow down the water flow and provide a resting place for migratory fish. The vortex identification method can more accurately identify the vortex structure inside the flow field. [ABSTRACT FROM AUTHOR]

Photoactive Cu(I) complexes are promising luminescent materials owing to their abundant reserves and marvelous biocompatibility. In this work, we report the synthesis and characterization of two binuclear sulfur‐bridged Cu(I) complexes (POP)2Cu2(μ‐HS/Cl)2 ⋅ 0.92MeOH 1 (POP=(oxybis(2,1‐phenylene))bis(diphenylphosphine)) and (POP)2Cu2(μ‐HS)22, which were prepared by one‐pot facile solvothermal method with copper‐4‐tert‐butylbenzenethiol (CuSC6H4tBu) and POP as precursors. Complex 1 exhibits sky‐blue emission while complex 2 displays blue. Complex 1 was systemically investigated by PXRD, UV‐vis spectrum, IR, TGA and steady‐state spectra. Temperature‐dependent steady‐state emission and decay lifetime indicate that complex 1 is a typical phosphorescent emitter. [ABSTRACT FROM AUTHOR]

As traditional Chinese medicine and edible insects, Vespa hornets have high economic value and huge market demand. Hornet breeding has become an important way to increase the income of mountain farmers in China, but the limitation of traditional identification methods has become the bottleneck of the modern development of hornet resources. In this study, a simple and reliable method for the molecular identification of typical hornets from Yunnan was successfully established. In the NCBI database, DNA sequences of hornet samples were aligned as Vespa analis, Vespa basalis, Vespa velutina, Vespa mandarinia, Vespa magnifica, Vespa binghami, Vespa soror by BLAST search. The efficiency of the PCR amplification of mitochondrial cytochrome C oxidase I (COI) gene sequences in all samples was 100% by using the optimized program. Moreover, a reference database for DNA barcodes of Vespa materials in Yunnan was constructed. This study provided a successful example for the identification of local insects of Yunnan and will be helpful to the development of wasp resources. [ABSTRACT FROM AUTHOR]

Objective: To summarize data from a serological survey of high‐risk populations in Guangdong Province, China, and to perform a meta‐analysis to investigate the prevalence and seroprevalence of celiac disease (CD) in the Chinese general and high‐risk populations. Methods: We collected data from the serological survey of high‐risk population of CD in Guangdong Province, China (N = 1390) by testing their serum tissue transglutaminase immunoglobulin A (tTG‐IgA), deamidated gliadin peptides immunoglobulin A (DGP‐IgA) and deamidated gliadin peptides immunoglobulin G (DGP‐IgG). Additionally, a literature search was performed on PubMed, EMBASE, Cochrane Library and three Chinese databases for articles published up to 20 December 2020 to estimate the pooled prevalence and seroprevalence of CD in China. Results: In the serological survey, 0.94% (13/1390) of individuals were positive for CD antibodies. In a meta‐analysis of 18 studies, the seroprevalence of CD in the general Chinese population was 0.27% (95% confidence interval [CI] 0.02%‐0.71%). While that in the high‐risk population was 8.34% (95% CI 4.90%‐12.54%) (odds ratio 7.27, 95% CI 4.06‐13.04). The prevalence of biopsy‐confirmed CD in high‐risk Chinese populations was 4.44% (95% CI 1.53%‐8.58%). The seroprevalence of CD varied with patients' geographical origin, being higher in northern China than in southern China. Conclusions: Early diagnosis of CD by serological screening in high‐risk population and generous serological testing in those with vague symptoms, especially in northern China, are recommended. [ABSTRACT FROM AUTHOR]

Deformation behavior of a high‐Ti low‐C microalloyed steel is studied by isothermal compression tests at temperatures of 800–1100 °C and strain rates of 0.1–10 s−1. The results indicate that the lower the strain rate and higher the temperature of steel, the more likely is the dynamic recrystallization. The stress–strain predicted by the constitutive model, which is established based on the experimental data, are in good agreement with the experimental results. It is noted from the processing maps of steel at various strains that there is instability zone which should be avoided during thermal processing at strain rate less than 1 s−1. The range of 850–1100 °C and 5–10 s−1 strain rate is more conducive to the processing of experimental steel. The movement of grain boundaries, subboundaries, and dislocations is hindered by precipitates in steel. In addition, the mean grain size of austenite at 0.1 s−1 is larger than 5 s−1. This is mainly because low strain rate provides more time for growth of grains. [ABSTRACT FROM AUTHOR]

The hot ductility behavior of high‐Ti weathering steel is studied by high‐temperature tensile testing in the temperature range of 650–1100 ºC. The results reveal a ductility trough in high‐Ti steel in the range of 650–962, 650–925, and 700–880 °C with minimum reduction in area (RA) of 22.21%, 36.53%, and 43.25% at 800 ºC and different strain rates of 1.0 × 10−3, 5.0 × 10−3, and 1.0 × 10−2 s−1, respectively. A number of secondary cracks containing S, N, and Ti propagate along the grain boundary, and the obvious preferred orientation is found in the microstructure near the fracture at 800 °C. With the increase in strain rate, the value of RA is increased in the temperature range of 650–1050 ºC, such that the probability of crack occurrence is decreased. RA does not increase with the increase in strain rate at 1100 °C and strain rate of 1.0 × 10−2 s−1. The underlying reason is that there is not adequate time for the material to recover or recrystallize with the increase in strain rate, resulting in material softening effect that is not completely reflected. [ABSTRACT FROM AUTHOR]

We report an oxidative ring‐opening strategy to transform cyclopropylamides and cyclobutylamides into fluorinated imines. The imines can be isolated in their more stable hemiaminal form, with the fluorine atom installed selectively at the γ or δ position. Both inexpensive benzophenone with UVA light or organic and inorganic dyes with blue light could be used as photoredox catalysts to promote this process. Various fluorinated amines were then obtained by nucleophilic attack on the hemiaminals in one pot, giving access to a broad range of useful building blocks for medicinal chemistry. [ABSTRACT FROM AUTHOR]

Diamine‐pillared α‐titanium phosphate (α‐TiP) was prepared via direct ion exchange method. Moreover, 1,3‐propanediamine, as the pillaring agent, was used to investigate the effect of pH, content and temperature on the interlayer distance of α‐TiP. The structure and properties of the samples were characterized by X‐ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT‐IR), Field Emission Scanning Electron Microscopy (SEM), and Differential Thermal Analysis (TG). The results show that the interlayer distance of α‐TiP was enlarged from 7.6 Å to 16.18 Å as the carbon chain of the intercalating diamine increased from (NH2(CH2)nNH2) (n = 2 to 7). The layer space structure consists of monomolecular alkyl chains with an average tilt angle of 75.6°. The uptake values for these five alkyldiamine cations were 3.780, 3.261, 2.443, 2.175, and 1.954 mmol, per gram of TiP, respectively. Also, we found that the direct ion exchange method is more effective in a weak acidic environment. The variation of interlayer distance was a consecutive process, and unaffected by temperature. The 1,3‐propanediamine intercalation product (α‐TiPPda) showed excellent performance towards EuIII adsorption in water with removal efficiencies ≥ 99 %. [ABSTRACT FROM AUTHOR]

We report an oxidative ring‐opening strategy to transform acyl, sulfonyl or carbamate protected aminocyclopropanes into 1,3‐dielectrophilic carbon intermediates bearing a halide atom (Br, I) and a N,O‐acetal. Replacing the alkoxy group of the N,O‐acetal can be achieved under acidic conditions through an elimination–addition pathway, while substitution of the halides by nucleophiles can be done under basic conditions through a SN2 pathway, generating a wide range of 1,3‐difunctionalized propylamines. A proof of concept for asymmetric induction was realized using a chiral phosphoric acid (CPA) as catalyst, highlighting the potential of the method in enantioselective synthesis of important building blocks. [ABSTRACT FROM AUTHOR]

Abstract: Soil parameters, measured before crop planting, are typically used to quantify the relationship between soil properties and crop yield and to identify factors limiting crop yield. However, soil properties during sensitive stages of crop growth may have a greater effect on crop yield than the initial values. We determined if inclusion of soil properties, measured during the reproductive stage, could improve the accuracy of crop yield prediction. Classification and regression trees were used to determine the explanatory power of different soil and rice variables for predicting rice yield in alkaline salt‐affected paddy fields in northeast China. The traditional method explained 77.5% of the rice yield variation and identified soil CO32− in the 0‐ to 10‐cm soil layer, with single explanatory power of 53.4%, as the most important predictor. The whole explanatory power of the methods including soil variables during the reproductive stage and yield components, with/without soil variables before planting, increased to 81.3%. The residual sodium carbonate, measured in the 0‐ to 10‐cm soil layer during the reproductive stage, was identified as the most limiting factor due to its single maximum explanatory power of 60.5%. We conclude that inclusion of soil properties, measured during the reproductive stage, has potential for improving the rice yield prediction accuracy by enhancing the explanatory power in identification of the most limiting factor. These results encourage further investigation of the role of soil properties during sensitive stages of crop growth in crop yield prediction under different soil and climatic conditions. [ABSTRACT FROM AUTHOR]

Abstract: The first Lewis acid catalyzed enantioselective ring‐opening desymmetrization of a donor–acceptor meso‐diaminocyclopropane is reported. The copper(II)‐catalyzed Friedel–Crafts alkylation of indoles and one pyrrole with an unprecedented meso‐diaminocyclopropane delivered enantioenriched, diastereomerically pure urea products, which are structurally related to natural and synthetic bioactive compounds. The development of a new ligand through the investigation of an underexplored subclass of bis(oxazoline) ligands was essential for achieving high enantioselectivities. [ABSTRACT FROM AUTHOR]

The first Lewis acid catalyzed enantioselective ringopening desymmetrization of a donor–acceptor meso-diaminocyclopropane is reported. The copper(II)-catalyzed Friedel– Crafts alkylation of indoles and one pyrrole with an unprecedented meso-diaminocyclopropane delivered enantioenriched, diastereomerically pure urea products, which are structurally related to natural and synthetic bioactive compounds. The development of a new ligand through the investigation of an underexplored subclass of bis(oxazoline) ligands was essential for achieving high enantioselectivities. [ABSTRACT FROM AUTHOR]

One long-standing issue in directed C−H functionalization is that either nitrogen or sulfur atoms present in heterocyclic substrates may bind preferentially to a transition-metal catalyst rather than to the desired directing group. This competitive binding has largely hindered the application of C−H functionalization in late-stage heterocycle drug discovery. Reported here is the use of an oxazoline-based directing group capable of overriding the poisoning effect of a wide range of heterocycle substrates. The potential use of this directing group in pharmaceutical drug discovery is illustrated by diversification of Telmisartan (an antagonist for the angiotensin II receptor) through copper-mediated C−H amination, hydroxylation, thiolation, arylation, and trifluoromethylation. [ABSTRACT FROM AUTHOR]

The origin and evolution of polyploids have been studied extensively in angiosperms and ferns but very rarely in gymnosperms. With the exception of three species of conifers, all natural polyploid species of gymnosperms belong to Ephedra, in which more than half of the species show polyploid cytotypes. Here, we investigated the origin and evolution of polyploids of Ephedra distributed in the Qinghai-Tibetan Plateau ( QTP) and neighbouring areas. Flow cytometry ( FCM) was used to measure the ploidy levels of the sampled species that are represented by multiple individuals from different populations, and then, two single-copy nuclear genes ( LFY and DDB2) and two chloroplast DNA fragments were used to unravel the possible origins and maternal donors of the polyploids. The results indicate that the studied polyploid species are allopolyploids, and suggest that allotetraploidy is a dominant mode of speciation in Ephedra. The high percentage of polyploids in the genus could be related to some of its biological attributes such as vegetative propagation, a relatively high rate of unreduced gamete formation, and a small genome size relative to most other gymnosperms. Significant ecological divergences between allotetraploids and their putative progenitors were detected by PCAs and anova and Tukey's tests, with the exception of E. saxatilis. The overlap of geographical distributions and ecological niches of some diploid species could have provided opportunities for interspecific hybridization and allopolyploid speciation. [ABSTRACT FROM AUTHOR]

In the cation of the title hydrated salt, C19H21N2O2S2 (+)·I(-)·H2O, the benzo-thia-zolium ring system is approximately planar [maximum deviation = 0.0251 (15) Å], and it makes a small dihedral angle of 1.16 (18)° with the plane of the thio-phene ring. In the crystal, the cations, anions and crystalline water mol-ecules are linked by classical O-H⋯O, O-H⋯I and weak C-H⋯O hydrogn bonds, forming a three-dimensional supra-molecular network. π-π stacking is observed between parallel thia-zole rings of adjacent cations [centroid-centroid distance = 3.5945 (16) Å].