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ObjectiveTo establish a method for the determination of food additive theaflavins by ultraviolet spectrophotometry.MethodsAfter dissolved in water， the sample solution was extracted with ethyl acetate and 2.5% sodium bicarbonate solution in turn. A certain volume of ester phase was fixed with ethanol， and then it was quantified by spectrophotometry. The maximum absorption wavelength， sample quality， concentration of sodium bicarbonate solution and extraction time by sodium bicarbonate solution were researched.ResultsUnder the best conditions， four theaflavin monomers had good linear relationships within their respective concentration ranges， and the correlation coefficients were all greater than 0.999. The limit of quantitation was 3%， the standard recoveries were 95.2%-108.4%， and the relative standard deviations were less than 5%.ConclusionThis method has good repeatability， precision and stability， and is suitable for the determination of food additive theaflavin.

Background: Limited supply of certain nutrients and deregulation of nucleus pulposus (NP) plays a key role in the pathogenesis of intervertebral disc degeneration (IVDD). However, whether nutrient deprivation-induced cell death, particularly disulfidptosis, contributes to the depletion of NP cells and the development of IVDD, is unknown. Methods: RNA-seq, single-cell RNA-seq, and Genome-wide DNA methylation datasets of nucleus pulposus tissue were collected for bioinformatic analysis. Predictive models of disulfidptosis related genes in IVDD were constructed by machine learning and their differential expression was analyzed. In addition, we performed cell subsets identification analysis, cell-cell communications analysis, and functional enrichment analysis of key genes in the core subset based on single-cell RNA-seq data of NP tissues isolated from one normal sample and one IVDD sample. Finally, glucose deprivation-induced disulfidptosis in human NP cells (HNPCs) was verified by various cell death inhibitors and disulfidptosis-related molecular markers. Results: We found the disulfidptosis signal was significantly activated in the IVDD group. Using single-cell RNA-seq analysis, we focused on the chondrocytes and found that disulfidptosis-related genes significantly highly expressed in the IVDD C4 chondrocyte subset, which was identified as a new disulfidptosis-associated cell subset. Correlation analysis revealed the negative correlation between SLC7A11 (driving gene of disulfidptosis) and the glucose transporter GLUTs (SLC2A1-4) family genes (suppressing genes of disulfidptosis) in the IVDD group. We also found obvious cell death in HNPC upon glucose starvation, while employment of various cell death inhibitors could not inhibit glucose starvation-induced death in HNPCs. Moreover, the accumulation of disulfide bonds in cytoskeletal proteins was indicated by slowed migration in non-reducible protein blotting experiments. 2-DG, a key disulfidptosis inhibitor, significantly rescued cell death caused by glucose starvation through lowering the NADP+/NADPH ratio. Conclusions: We validated the occurrence of disulfidptosis in HPNCs and identified a novel disulfidptosis-associated cell subset, followed by experimental verification of disulfidptosis in a glucose-limited context to mimic a fall in nutrient supply during the development disc degeneration. These findings provided new insights into the pathological mechanisms of IVDD and encourage us to explore potential therapeutic targets involved in the regulation of disulfidptosis for the prevention of intervertebral disc degeneration. [ABSTRACT FROM AUTHOR]

BackgroundThe aim of the study was to examine the clinical incidence rate of vertebral body fractures after percutaneous vertebroplasty (PVP) with and without brace wearing and provide a new guiding ideology for preventing vertebral fractures after clinical surgeries.MethodsThe retrospective analysis included 100 outpatients who underwent PVP between January 2017 and December 2018 without bracing after PVP surgeries (non-brace-wearing group). In total, 100 patients were paired into the rigid brace group and 100 patients were paired into the soft braces group according to propensity score matching. Seven independent variables were used in the soft and rigid brace group: age, sex, body mass index (BMI), visual analog scale (VAS), Oswestry Disability Index (ODI), and Cobb angle. The VAS, ODI, and Japanese Orthopaedic Association (JOA) scores were recorded preoperatively on the second day, after 1 month, after 3 months, and during the last follow-up postoperatively. We recorded the incidence of vertebral refracture in each of the three groups of patients and evaluated the effect of braces on postoperative fractures based on the ODI, VAS, and JOA scores.ResultsAll patients were followed up for 8–24 months (mean 22.4 months). Compared with the preoperative values, the age, sex, BMI, bone density, ODI, VAS, and Cobb angle between refracture and non-refracture were not statistically significant. The VAS, ODI, and JOA scores significantly increased in the brace-wearing group compared with those of the non-brace-wearing group (p 0.05). The improvement in the JOA score of the soft brace group was better than that of the rigid brace group, between which there was a significant difference (p

The ubiquitin–proteasome system (UPS) maintains intracellular protein homeostasis and cellular function by regulating various biological processes. Ubiquitination, a common post-translational modification, plays a crucial role in the regulation of protein degradation, signal transduction, and other physiological and pathological processes, and is involved in the pathogenesis of various cancers, including osteosarcoma. Osteosarcoma, the most common primary malignant bone tumor, is characterized by high metastatic potential and poor prognosis. It is a refractory bone disease, and the main treatment modalities are surgery combined with chemotherapy. Increasing evidence suggests a close association between UPS abnormalities and the progression of osteosarcoma. Due to the complexity and pleiotropy of the ubiquitination system, each step in the ubiquitination process can be targeted by drugs. In recent years, research and development of inhibitors targeting the ubiquitin system have increased gradually, showing great potential for clinical application. This article reviews the role of the ubiquitination system in the development and treatment of osteosarcoma, as well as research progress, with the hope of improving the therapeutic effects and prognosis of osteosarcoma patients by targeting effective molecules in the ubiquitination system. [ABSTRACT FROM AUTHOR]

Because the water content of fresh daylily is high, the quality of fresh daylily decreases rapidly after harvest. It is very important to explore the suitable processing methods for extending the shelf life of daylily. The effects of different vacuum pulsating preventive technology (PVD) conditions on nutritional composition, color, flavor, rehydration rate and microstructure of daylily were investigated, so as to improve the quality of dried daylily. The effects of different drying temperatures (65, 70, 75, 80 " and 85 ") on the quality of daylilies were studied under the conditions of vacuum holding time (10 min) and atmospheric holding time (5 min) using PVD equipment. Furthermore, principal component analysis and partial least squares method were used to discriminate the drying process, flavor composition and characteristic taste of daylily. The results showed that the content of free amino acids in naturally dried (CK) daylily was the highest, at 0.858 mg/g. The !E value was the highest, at 16.47, further indicating that the overall quality of the sample was poor. After PVD drying, daylily has a bright and vibrant color, good rehydration performance, and significantly increased protein and flavonoid content. When PVD was 80 ", the primary color retention rate was the highest (!E= 7.28), and the free amino acid content was the highest (0.818 mg/g). When PVD was 75 ", the protein (7.331 g/L) and Ga (1072.445 "g/kg) content in the sample was the highest. When PVD was 70 the proportion of /3-fold and "helix content in the daylily sample was the highest, at 35%. When PVD was 65 the flavonoid content (1.653 mg/g) and rehydration rate are the highest (3.04%), and inorganic sulfides, nitrogen oxides, and terpenoids can be well retained. In addition, partial least squares discriminant analysis revealed that aspartic acid, histidine, serine, glutamic acid, and alanine are characteristic taste substances of daylily. Conclusion: Different PVD drying temperatures lead to differences in the physicochemical properties and nutritional components of daylily. The research results can provide suitable process parameters to meet different quality attribute requirements and consumer acceptance. [ABSTRACT FROM AUTHOR]

Microbial load, protein oxidation, myofibrillar protein changes and quality characteristics (meat color and water retentiveness including centrifugal loss (CeL) and water-holding capacity (WHC)) of post-rigor tan mutton exposed to different high-pressure treatments (200 MPa/500 MPa for 15 min at 18°C) during chilled storage for 7 days (4°C) were evaluated. High-pressure applications of 200 MPa and 500 MPa significantly reduced the number of Total Viable Counts (TVC) during storage (P 0.05) and better texture characteristics than untreated samples. ANOVA with Partial Least Squares Regression (APLSR) confirmed the relationshipS between these variations in quality characteristics induced by high-pressure treatments and protein oxidation and key myofibrillar skeleton proteins.