71 research outputs found
Direct in-vitro assay of resistant starch in phosphorylated cross-linked starch
Direct assay of resistant starch (RS) in food and feed is accomplished by (i) removal of lipid, protein, and digestible starch to obtain insoluble dietary fiber, and (ii) dissolution of the resistant starch in the insoluble fiber followed by its quantification with specific enzymes. Phosphorylated cross-linked (CL) RS resists dissolution and therefore has not been assayed directly. The objective of this study was to develop a method to solubilize the RS fraction in phosphorylated (0.4% phosphorus) CL wheat starch (RS4) after its incubation with α-amylase and amyloglucosidase for 16 h at 37 °C as directed by the RS assay AOAC Method 2002.02. The residue was hydrolyzed and solubilized by conducting two back-to-back incubations with thermostable α-amylase for 30 min at 100 °C and pH 5.0, cooling to 50 °C, then incubating quickly with amyloglucosidase at 50 °C for 1 h at pH 5.0. Importantly, the cooling process after α-amylase incubation was done by placing the mixture in a water bath at 50 °C. The degree of hydrolysis of the CL phosphorylated wheat starch was determined as d-glucose using high-performance anion-exchange chromatography with pulsed amperometric detection (99.0%), glucose-oxidase/peroxidase (95.3%), and phenol-sulfuric acid determination of total carbohydrate (105.2%). Based on those findings, we propose a direct determination of RS in foods containing phosphorylated CL wheat starch
Study on rainfall infiltration characteristic parameters of unsaturated soil
The study of the rainfall infiltration mechanism of unsaturated soil has always been a hot issue in the field of geotechnical engineering. It is worth studying which parameters should be introduced to characterize the infiltration characteristics of unsaturated soil in the calculation and analysis of rainfall infiltration. In this paper, the Fredlund–Xing model was quoted in the SEEP/W module of the Geostudio software, and the transient numerical calculation of rainfall infiltration under the same rainfall duration T and different rainfall intensity I was carried out for a soil column. Three infiltration characteristic parameters were introduced: rainfall infiltration front depth WF, suction reduction depth MRn, and section infiltration rate IR. The variation of these three parameters and rainfall intensity I during rainfall were sorted out and analyzed; it is indicated that WF increases with the extension of rainfall duration. MRn decreases with the increase of suction reduction rate n%, and when the rainfall duration is 24 h, the maximum depth of the soil column affected by rainfall is approximately 35% of the total depth. IR is mainly affected by the rainfall intensity I and the saturation permeability coefficient ks. There is a limit value for the influence of I on WF, MRn, and IR, and the limit rainfall intensity under the calculation conditions in this paper is I = 2.5ks
3D Bioprinting tissue analogs: Current development and translational implications
Three-dimensional (3D) bioprinting is a promising and rapidly evolving technology in the field of additive manufacturing. It enables the fabrication of living cellular constructs with complex architectures that are suitable for various biomedical applications, such as tissue engineering, disease modeling, drug screening, and precision regenerative medicine. The ultimate goal of bioprinting is to produce stable, anatomically-shaped, human-scale functional organs or tissue substitutes that can be implanted. Although various bioprinting techniques have emerged to develop customized tissue-engineering substitutes over the past decade, several challenges remain in fabricating volumetric tissue constructs with complex shapes and sizes and translating the printed products into clinical practice. Thus, it is crucial to develop a successful strategy for translating research outputs into clinical practice to address the current organ and tissue crises and improve patients' quality of life. This review article discusses the challenges of the existing bioprinting processes in preparing clinically relevant tissue substitutes. It further reviews various strategies and technical feasibility to overcome the challenges that limit the fabrication of volumetric biological constructs and their translational implications. Additionally, the article highlights exciting technological advances in the 3D bioprinting of anatomically shaped tissue substitutes and suggests future research and development directions. This review aims to provide readers with insight into the state-of-the-art 3D bioprinting techniques as powerful tools in engineering functional tissues and organs
A Cis-Regulatory Map of the Drosophila Genome
Systematic annotation of gene regulatory elements is a major challenge in genome science. Direct mapping of chromatin modification marks and transcriptional factor binding sites genome-wide1, 2 has successfully identified specific subtypes of regulatory elements3. In Drosophila several pioneering studies have provided genome-wide identification of Polycomb response elements4, chromatin states5, transcription factor binding sites6, 7, 8, 9, RNA polymerase II regulation8 and insulator elements10; however, comprehensive annotation of the regulatory genome remains a significant challenge. Here we describe results from the modENCODE cis-regulatory annotation project. We produced a map of the Drosophila melanogaster regulatory genome on the basis of more than 300 chromatin immunoprecipitation data sets for eight chromatin features, five histone deacetylases and thirty-eight site-specific transcription factors at different stages of development. Using these data we inferred more than 20,000 candidate regulatory elements and validated a subset of predictions for promoters, enhancers and insulators in vivo. We identified also nearly 2,000 genomic regions of dense transcription factor binding associated with chromatin activity and accessibility. We discovered hundreds of new transcription factor co-binding relationships and defined a transcription factor network with over 800 potential regulatory relationships
Involvement of inflammation-related miR-155 and miR-146a in diabetic nephropathy: implications for glomerular endothelial injury
Key Technologies of Spraying Machine with Wireless Remote Control
In this research, a wireless remote-controlled (RC) spraying machine is developed based on the S3C6410 embedded controller. This spraying machine is composed of a rotary pesticide selection unit, a real-time mixing unit, a multi-angle spraying unit, an image acquisition module, an embedded control module, a wireless communication module, and an intelligent mobile platform. It is especially designed for hilly areas, greenhouses, orchards, and other environments that are not accessible to large and medium-sized spraying machines. The wireless RC machine achieves precise proportional and multi-angle flexible spraying while avoids liquid waste and direct operator–liquid contact
Time-series variation and attribution analysis of downward shortwave radiation over the Yunnan-Kweichow plateau from 1984 to 2018
The downward shortwave radiation (DSR) is a key input parameter for land surface models and climate models. Based on the daily averaged Global Land Surface Satellite downward shortwave radiation (GLASS-DSR) dataset over the Yunnan-Kweichow Plateau (YKP) from 1984 to 2018, this paper analyzes variation trend and breakpoints of DSR. The results show that: annual averaged DSR decreases at a decreasing rate of −1.84 W·m−2·decade−1 over the YKP from 1984 to 2018; the overall distribution of interannual averaged DSR shows higher in the mid-west, and gradually decreasing from west to northeast over the YKP; the estimated averaged DSR is larger in spring than in summer due to the influence of the monsoon; monthly averaged DSR reaches its maximum in May and its minimum in December; breakpoints are found in the seasonal and trend components of daily averaged DSR. Eleven driving factors are examined for their effects on DSR variation, including annual average temperature, precipitation, 10 m wind speed, aerosol optical thickness (AOT), total cloud cover, elevation, slope, aspect, longitude, latitude, and climate zones. According to the findings, AOT predominates in the spatio-temporal distribution of DSR over the YKP. This study will contribute to studies related to climate change and highland radiation
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