The decline in species richness at higher latitudes is among the most fundamental patterns in ecology. Whether changes in species composition across space (beta-diversity) contribute to this gradient ...of overall species richness (gamma-diversity) remains hotly debated. Previous studies that failed to resolve the issue suffered from a well-known tendency for small samples in areas with high gamma-diversity to have inflated measures of beta-diversity. Here, we provide a novel analytical test, using beta-diversity metrics that correct the gamma-diversity and sampling biases, to compare beta-diversity and species packing across a latitudinal gradient in tree species richness of 21 large forest plots along a large environmental gradient in East Asia. We demonstrate that after accounting for topography and correcting the gamma-diversity bias, tropical forests still have higher beta-diversity than temperate analogues. This suggests that beta-diversity contributes to the latitudinal species richness gradient as a component of gamma-diversity. Moreover, both niche specialization and niche marginality (a measure of niche spacing along an environmental gradient) also increase towards the equator, after controlling for the effect of topographical heterogeneity. This supports the joint importance of tighter species packing and larger niche space in tropical forests while also demonstrating the importance of local processes in controlling beta-diversity.
Axial flux permanent magnet synchronous motor is superior to other types of motors in terms of efficiency, torque and size. However, torque ripple is a problem that cannot be ignored in axial flux ...permanent magnet synchronous motor, which further increases the vibration and noise of the motor and reduces the control accuracy. Therefore, this paper will suppress torque ripple by optimizing the method of permanent magnet tilt and chamfering. Taking the 16-pole 24-slot dual-rotor single-stator axial flux permanent magnet synchronous motor as an example, the finite element method is used to simulate and analyze different tilt angles, and the most suitable tilt angle that does not affect the performance of the motor is determined. The optimized motor model is simulated and analyzed, and the torque ripple is reduced by 64%, which verifies the feasibility of the method.
以关中奶山羊羔羊皱胃为原料，分别用pH 4.5，5.4和6.0提取液提取羔羊皱胃酶，并用L9(34)正交试验研究了不同pH提取液对皱胃酶提取效果的影响。结果表明，pH 5.4提取液的提取活性最高，pH 6.0提取液次之，pH 4.5提取液最低;其最佳技术参数为：提取液pH 5.4，NaCl质量浓度80 g/L，提取温度30 ℃，皱胃质量与提取液体积之比为1∶20；提取时间48 h。
Using ...goat kid abomasum of Guanzhong dairy goats as material, kid rennet was extracted with pH 4.5,pH 5.4 and pH 6.0 buffers respectively, and effect of different factors on the extracting activity of kid rennet in different pH buffers was studied by L9(34) orthogonal experiment. The results showed that the extracting activity of kid rennet in pH 5.4 buffer ranked the highest,pH6.0 buffer the second, pH 4.5 buffer the last, and the best technological parameters ware extracting solution pH 5.4,NaCl concentration 80 g/L, extracting temperature 30 ℃,ratio of abomasums and buffer 1∶20,and extracting time 48 hours.
The structural characterization, the in vitro antioxidant activity, and the hypoglycemic activity of a polysaccharide (SGP-1-1) isolated from Siraitia grosvenorii (SG) were studied in this paper. ...SGP-1-1, whose molecular weight is 19.037 kDa, consisted of Gal:Man:Glc in the molar ratio of 1:2.56:4.90. According to the results of methylation analysis, GC–MS, and NMR, HSQC was interpreted as a glucomannan with a backbone composed of 4)-β-D-Glcp-(1→4)-, α-D-Glcp-(1→4)-, and 4)-Manp-(1 residues. α-1,6 linked an α-D-Galp branch, and α-1,6 linked an α-D-Glcp branch. The study indirectly showed that SGP-1-1 has good in vitro hypoglycemic and antioxidant activities and that these activities may be related to the fact that the SGP-1-1’s monosaccharide composition (a higher proportion of Gal and Man) is the glycosidic-bond type (α- and β-glycosidic bonds). SGP-1-1 could be used as a potential antioxidant and hypoglycemic candidate for functional and nutritional food applications.
Radix Astragali (RA) consists of the dried root of Astragalus membranaceus Bunge and is one of the most frequently used dietetic Chinese herbs to treat inflammation and neurodegenerative disease ...among other conditions. Radix Astragali preparata (RAP) is a medicinal form of RA. RA and RAP have been used as anti-aging agent, however, the mechanisms underlying their effects are still unclear.
Considering the wide application of RA and RAP in clinical practice, it is necessary to identify the better product between the two and elucidate the molecular mechanism responsible for their anti-aging effects.
In this study, network pharmacology integrated with molecular biology techniques were employed to explore the possible mechanism of RA and RAP against aging.
Aging animal models were constructed by exposure to D-galactose (D-gal), and the anti-aging effect of RA and RAP were determined based on behavior tests and histomorphological observation. Network pharmacology was performed to construct the “compound-target-pathway” network. Gene and protein expression of possible targets were validated and analyzed using qRT-PCR and Western blotting.
Treatment by RA and RAP could alleviate the symptoms of aging such as a decrease in body weight and organ indices, behavioral impairment, increased oxidative stress, weaken histopathological evaluation. The effect of RAP was more pronounced than that of RA in preventing aging process in a mouse model. The anti-aging effect of RA and RAP is associated with the balance of oxidative stress and activation of PI3K/Akt signaling pathway.
Using an integrated strategy of network pharmacology and molecular biology we attempted to elucidate the mechanisms of action of RA and RAP.
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Summary
In vitro digestion models are widely used to study the structural changes, digestion and release of food components under simulated gastrointestinal conditions. As compared to the in vivo ...digestion tests, the in vitro digestion reflects the digestion and utilisation of food after ingestion and has the advantages of being time consuming, inexpensive, reproducible and free from moral and ethical restrictions. This study reviewed the current research studies on the in vitro simulated digestion of polysaccharides conducted in the last 5 years and focused on the oral, gastric and intestinal digestion models, with the aim of providing a basis for the further testing of changes in the content, structure and active ingredients of polysaccharides before and after digestion.
Advances in the in vitro digestion and fermentation of polysaccharides.
Improving yield is one of the most important targets of sesame breeding. Identifying quantitative trait loci (QTLs) of yield-related traits is a prerequisite for marker-assisted selection (MAS) and ...QTL/gene cloning. In this study, a BC
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population was developed and genotyped with the specific-locus amplified fragment (SLAF) sequencing technology, and a high-density genetic map was constructed. The map consisted of 13 linkage groups, contained 3528 SLAF markers, and covered a total of 1312.52 cM genetic distance, with an average distance of 0.37 cM between adjacent markers. Based on the map, 46 significant QTLs were identified for seven yield-related traits across three environments. These QTLs distributed on 11 linkage groups, each explaining 2.34–71.41% of the phenotypic variation. Of the QTLs, 23 were stable QTLs that were detected in more than one environment, and 20 were major QTLs that explained more than 10% of the corresponding phenotypic variation in at least one environment. Favorable alleles of 38 QTLs originated from the locally adapted variety, Yuzhi 4; the exotic germplasm line, BS, contributed favorable alleles to only 8 QTLs. The results should provide useful information for future molecular breeding and functional gene cloning.
Breast cancer has become the leading cause of global cancer incidence and a serious threat to women's health. Accurate diagnosis and early treatment are of great importance to prognosis. Although ...clinically used diagnostic approaches can be used for cancer screening, accurate diagnosis of breast cancer is still a critical unmet need. Here, we report a 4-plex droplet digital PCR technology for simultaneous detection of four small extracellular vesicle (sEV)-derived mRNAs (PGR, ESR1, ERBB2 and GAPDH) in combination with machine learning (ML) algorithms to improve breast cancer diagnosis. We evaluate the diagnsotic results with and without the assistance of the ML models. The results indicate that ML-assisted analysis exhibits higher diagnostic performance even using a single marker for breast cancer diagnosis, and demonstrate improved diagnostic performance under the best combination of biomarkers and suitable ML diagnostic model. Therefore, multiple sEV-derived mRNAs analysis coupled with ML not only provides the best combination of markers for breast cancer diagnosis, but also significantly improves the diagnostic efficiency of breast cancer.
•A 4-plex droplet digital PCR is developed for multiplexed detection of sEV-derived PGR, ESR1, ERBB2 and GAPDH mRNAs for breast cancer diagnosis.•Droplet digital PCR entitles this method enough sensitivity, excellent stability, and applicability in clinic.•Multiplexed detection coupled with machine learning provides the best combination of biomarkers for improving breast cancer diagnosis.
Hairy composite particles with polymer nanoscale hairs are grown by precipitated cationic living polymerization onto a particle surface. Composition and length of the hairs are tuneable. The hair ...growth is general following the tip-growth mode. By step polymerization of varied monomers, multiple segmental hairs are achieved onto a particle surface. As an example, the PEG-conjugated PVBC-PDVB@Fe3O4 hairy particle is derived. It is highly effective to capture oil from the aqueous surroundings and easily recycled with a magnet.
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•Polymer nanofibers were constructed on a particle surface by precipitated cationic polymerization.•Multiple segmental fibers were achieved by step polymerization of varied monomers.•The paramagnetic hairy particle can capture oil from aqueous surroundings and be recycled with a magnet.
Multispecific antibodies (MsAbs) maintain the specificity of versatile antibodies while simultaneously addressing different epitopes for a cumulative, collaborative effect. They could be an ...alternative treatment to chimeric antigen receptor-T cell therapy by helping to redirect T cells to tumors in vivo. However, one major limitation of their development is their relatively complex production process, which involves performance of a massive screen with low yield, inconsistent quality, and nonnegligible impurities. Here, a poly(l-glutamic acid)-conjugated multiple Fc binding peptide-based synthesis nanoplatform was proposed, in which MsAbs were constructed by mixing the desired monoclonal antibodies (mAbs) with polymeric Fc binding peptides in aqueous solution without purification. To determine its efficacy, a dual immune checkpoint-based PD1/OX40 bispecific antibody and PDL1/CD3e/4-1BB trispecific antibody-based T cell engager were generated to trigger antitumor CD8+ T responses in mice, showing superior tumor suppression over free mixed mAbs. In this study, a facile, versatile build platform for MsAbs was established.
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