450 research outputs found

    Progress on two-dimensional ferrovalley materials

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    The electron's charge and spin degrees of freedom are at the core of modern electronic devices. With the in-depth investigation of two-dimensional materials, another degree of freedom, valley, has also attracted tremendous research interest. The intrinsic spontaneous valley polarization in two-dimensional magnetic systems, ferrovalley material, provides convenience for detecting and modulating the valley. In this review, we first introduce the development of valleytronics. Then, the valley polarization forms by the p, d, and f-orbit that are discussed. Following, we discuss the investigation progress of modulating the valley polarization of two-dimensional ferrovalley materials by multiple physical fields, such as electric, stacking mode, strain, and interface. Finally, we look forward to the future developments of valleytronics.Comment: 13 pages, 12 figures Accepted Chinese Physics B (2023) [Invited review

    (2S)-Ethyl 2-[(S s)-benzyl­sulfinyl­amino]-3,3-dimethylbutanoate

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    The title compound, C15H23NO3S, is an unexpected 1,3-migration product in the addition of benzyl­zinc bromide to N-tert-butane­sulfinyl imino­acetate. In the crystal structure, mol­ecules are linked by N—H⋯O hydrogen bonds and weak C—H⋯O hydrogen bonds

    The use of High-Fat/Carbohydrate Diet-Fed and Streptozotocin-Treated Mice as a Suitable Animal Model of Type 2 Diabetes Mellitus

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    This study defined a mouse model of type 2 diabetes that closely simulated the development and metabolic  abnormalities of the human disease. Male C57BL/6J mice were fed with diet enriched in fat and simple carbohydrate  for 6 weeks and then injected with streptozotocin (STZ, 150 mg/kg intraperitoneally) to develop type  2 diabetes. High-fat/carbohydrate-fed mice showed similar blood glucose concentrations to chow-fed mice, but  higher insulin concentrations (P<0.01). Hyperglycemia (17.6±3.27 mmol/L) was observed in these mice after  STZ injection, and the insulin concentrations decreased to the level comparable to, or still higher than, the normal.  The model mice showed impaired glucose tolerance in the oral glucose tolerance test (OGTT), and insulin  resistance in the insulin tolerance test (ITT). Moreover, these animals had lower glycogen storage (P<0.001),  higher serum free fatty acid (P<0.001), and higher triglycerides (P<0.05) levels compared with control mice.  Furthermore, the model mice were sensitive to the glucose lowering effect of metformin. In conclusion, this  mouse model could be considered as one of the suitable animal models for type 2 diabetes mellitus, and hence  can reasonably be used for type 2 diabetes pathophysiological research and therapeutic-compound evaluation.

    A new approach for the asymmetric syntheses of 2-epi-deoxoprosopinine and azasugar derivatives

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    A new approach to 2-epi-deoxoprosopinine 11, 1-deoxygulonojirimycin 7, and l-gulono-1,5-lactam 9 was described. The C-2 hydroxymethyl group was introduced regioselectively using SmI2 mediated coupling of (S)-3-silyloxyglutarimide 13b with either chloromethyl benzyl ether 16a or the Beau–Skrydstrup reagent 16b, followed by debenzylation and highly cis-diastereoselective reductive deoxygenation. Adoption of the Savoi's chemoselective ring-opening alkylation method allowed a highly diastereoselective introduction of the lipid side chain of 2-epi-deoxoprosopinine 11 in a straightforward manner. Dehydration followed by highly trans-diastereoselective dihydroxylation led to polyoxygenated lactam derivative 27 as a key intermediate for the syntheses of 7 and 9.the NSF of China (20272048; 203900505) and the Ministry of Education (Key Project 104201)

    Long-term nitrogen fertilization decreased the abundance of inorganic phosphate solubilizing bacteria in an alkaline soil

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    Inorganic phosphate solubilizing bacteria (iPSB) are essential to facilitate phosphorus (P) mobilization in alkaline soil, however, the phylogenetic structure of iPSB communities remains poorly characterized. Thus, we use a reference iPSB database to analyze the distribution of iPSB communities based on 16S rRNA gene illumina sequencing. Additionally, a noval pqqC primer was developed to quantify iPSB abundance. In our study, an alkaline soil with 27-year fertilization treatment was selected. The percentage of iPSB was 1.10 similar to 2.87% per sample, and the dominant iPSB genera were closely related to Arthrobacter, Bacillus, Brevibacterium and Streptomyces. Long-term P fertilization had no significant effect on the abundance of iPSB communities. Rather than P and potassium (K) additions, long-term nitrogen (N) fertilization decreased the iPSB abundance, which was validated by reduced relative abundance of pqqC gene (pqqC/16S). The decreased iPSB abundance was strongly related to pH decline and total N increase, revealing that the long-term N additions may cause pH decline and subsequent P releases relatively decreasing the demands of the iPSB community. The methodology and understanding obtained here provides insights into the ecology of inorganic P solubilizers and how to manipulate for better P use efficiency

    Generation of Genetically Modified Mice by Oocyte Injection of Androgenetic Haploid Embryonic Stem Cells

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    SummaryHaploid cells are amenable for genetic analysis. Recent success in the derivation of mouse haploid embryonic stem cells (haESCs) via parthenogenesis has enabled genetic screening in mammalian cells. However, successful generation of live animals from these haESCs, which is needed to extend the genetic analysis to the organism level, has not been achieved. Here, we report the derivation of haESCs from androgenetic blastocysts. These cells, designated as AG-haESCs, partially maintain paternal imprints, express classical ESC pluripotency markers, and contribute to various tissues, including the germline, upon injection into diploid blastocysts. Strikingly, live mice can be obtained upon injection of AG-haESCs into MII oocytes, and these mice bear haESC-carried genetic traits and develop into fertile adults. Furthermore, gene targeting via homologous recombination is feasible in the AG-haESCs. Our results demonstrate that AG-haESCs can be used as a genetically tractable fertilization agent for the production of live animals via injection into oocytes.PaperCli

    Whole-tumor histogram analysis of apparent diffusion coefficients for predicting lymphovascular space invasion in stage IB-IIA cervical cancer

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    ObjectivesTo investigate the value of apparent diffusion coefficient (ADC) histogram analysis based on whole tumor volume for the preoperative prediction of lymphovascular space invasion (LVSI) in patients with stage IB-IIA cervical cancer.MethodsFifty consecutive patients with stage IB-IIA cervical cancer were stratified into LVSI-positive (n = 24) and LVSI-negative (n = 26) groups according to the postoperative pathology. All patients underwent pelvic 3.0T diffusion-weighted imaging with b-values of 50 and 800 s/mm2 preoperatively. Whole-tumor ADC histogram analysis was performed. Differences in the clinical characteristics, conventional magnetic resonance imaging (MRI) features, and ADC histogram parameters between the two groups were analyzed. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic performance of ADC histogram parameters in predicting LVSI.ResultsADCmax, ADCrange, ADC90, ADC95, and ADC99 were significantly lower in the LVSI-positive group than in the LVSI-negative group (all P-values < 0.05), whereas no significant differences were reported for the remaining ADC parameters, clinical characteristics, and conventional MRI features between the groups (all P-values > 0.05). For predicting LVSI in stage IB-IIA cervical cancer, a cutoff ADCmax of 1.75×10−3 mm2/s achieved the largest area under ROC curve (Az) of 0.750, followed by a cutoff ADCrange of 1.36×10−3 mm2/s and ADC99 of 1.75×10−3 mm2/s (Az = 0.748 and 0.729, respectively), and the cutoff ADC90 and ADC95 achieved an Az of <0.70.ConclusionWhole-tumor ADC histogram analysis has potential value for preoperative prediction of LVSI in patients with stage IB-IIA cervical cancer. ADCmax, ADCrange, and ADC99 are promising prediction parameters

    Habitual snoring, adiposity measures and risk of type 2 diabetes in 0.5 million Chinese adults:a 10-year cohort

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    OBJECTIVES: The present study aimed to examine whether habitual snoring was independently associated with risk of type 2 diabetes among Chinese adults, and to assess the role that adiposity measures play in the snoring-diabetes association, as well as to evaluate the joint influence of snoring and adiposity measures on diabetes. RESEARCH DESIGN AND METHODS: The China Kadoorie Biobank study recruited 512 715 adults aged 30-79 years from 10 regions in China during 2004 and 2008. Data from 482 413 participants without baseline diabetes were analyzed in the present study. Autoregressive cross-lagged panel analysis was used to assess the longitudinal relationship between adiposity measures and habitual snoring. Cox proportional hazards models were used to examine the association between habitual snoring and diabetes risk. RESULTS: Both higher body mass index and waist circumference were associated with higher risks of subsequent habitual snoring, whereas no reverse association was detected. A total of 16 479 type 2 diabetes cases were observed during a 10-year follow-up. Habitual snoring was independently associated with 12% (95% CI 6% to 18%) and 14% (95% CI 9% to 19%) higher risks of diabetes among men and women, respectively. Habitual snorers who had general obesity or central obesity were about twice as likely to develop diabetes as non-snorers at the lowest levels of adiposity measures. CONCLUSION: Habitual snoring was independently associated with a higher risk of type 2 diabetes among Chinese adults. It is important to maintain both a healthy weight and a normal waist circumference to prevent or alleviate habitual snoring and ultimately prevent diabetes among Chinese adults
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