Monitoring the baking quality of Tieguanyin via electronic nose combined with GC-MS.

Roasting is extremely important for Tieguanyin oolong tea production because it strongly affects its chemical composition and sensory quality. In addition, there were significant differences in the preference for roasted tea among different people. However, the effect of roasting degree on the aroma characteristics and flavor quality of Tieguanyin tea is still unclear. To further study this, an electronic nose combined with gas chromatography-mass spectrometry (GC-MS) was used to monitor the baking process of Tieguanyin. The physicochemical indexes, sensory quality, and odor characteristics of the tea leaves subjected to different roasting conditions were measured. The increase in the roasting degree caused a decrease in the amount of taste substances such as tea polyphenols, catechins, and amino acids and a sharp increase in the phenol to ammonia ratio. Sensory evaluation results showed that moderate roasting could help improve the quality of the tea leaves. The results obtained using the electronic nose and GC-MS showed that there were substantial differences in the volatile substances, and 103 flavor compounds were highly correlated with the aroma characteristics of roasted tea with different roasting degrees. In addition, the electronic nose combined with various classification models could better distinguish tea leaves with different roasting degrees. Among them, the accuracy of the RF training set and prediction set reached>98.44%. The results of this study will aid in comprehensively monitoring the effects of the baking process on the flavor, chemical composition, and aroma of Tieguanyin as well as in distinguishing Tieguanyin tea leaves with different qualities.

Associations of fine particulate matter and its metal constituents with blood pressure: A panel study during the seventh World Military Games.

Evidence is needed to elucidate the association of blood pressure (BP) changes with metal constituents in fine particulate matter (PM2.5). Therefore, we designed a longitudinal panel study enrolling 70 healthy students from Wuhan University in the context of the seventh World Military Games (the 7th WMG) from September 2019 to January 2020. A total of eight visits were conducted before, during, and after the 7th WMG. During every visit, each participant was asked to carry a personal PM2.5 monitor to measure hourly PM2.5 levels for three consecutive days. Questionnaire investigation and physical examination were completed on the fourth day. We analyzed ten metal constituents of ambient PM2.5 collected from the fixed station, and blood pressure was recorded during each visit. The linear mixed-effects models were performed to evaluate associations of metal constituents and blood pressure measurements. We observed a dramatic variation of PM2.5 concentration ranging from 7.38 to 132.04 µg/m3. A 10 µg/m3 increment of PM2.5 was associated with an increase of 0.64 mmHg (95% CI: 0.44, 0.84) in systolic BP (SBP), 0.40 mmHg (0.26, 0.54) in diastolic BP (DBP), 0.31 mmHg (0.15, 0.47) in pulse pressure (PP) and 0.44 mmHg (0.26, 0.62) in mean artery pressure (MAP), respectively. For metal constituents in PM2.5, robust positive associations were observed between BP and selenium, manganese, arsenic, cadmium, and thallium. For example, for an IQR (0.93 ng/m3) increment of selenium, SBP and MAP elevated by 0.98 mmHg (0.09, 1.87) and 0.71 mmHg (0.03, 1.39), respectively. Aluminum was found to be robustly associated with decreased SBP, DBP, and MAP. The study indicated that exposure to PM2.5 total mass and metal constituents including selenium, manganese, arsenic, cadmium, and thallium were associated with the elevated BP.

Antihypertensive and renal protective effect of Shunaoxin pill combined with captopril on spontaneous hypertension rats.

INTRODUCTION: According to previous reports, hypertension has become the most common chronic disease in the world. Captopril, an angiotensin-converting enzyme inhibitor, has been widely used for the therapy of arterial hypertension and cardiovascular diseases therapy. Besides, Shunaoxin pill (SNX) as a traditional Chinese prescription showed antihypertensive effect in our previous research. OBJECTIVE: This study means to investigate whether SNX combining with captopril could show antihypertensive and renal protective effects on spontaneous hypertension rats (SHRs). METHODS: SHRs were randomly assigned to four treatment groups, including non-treated group, captopril, SNX, and captopril + SNX-treated groups. Their body weight and systolic blood pressure (SBP) were measured weekly. Histopathological examination was analyzed through Masson staining and hematoxylin and eosin staining. Biochemical analyses, ELISA, and western blot were used to analyze their combining mechanism. RESULTS: In this experiment, this combinatorial therapy significantly reduced aortic wall thickness, increased the content of NO, NOS and eNOS, decreased the content of bradykinin and endothelin 1(ET-1), and regulated the levels of TG, TC and HDLC back to normal, which suggested they could induce vasodilation and lower blood pressure. Meanwhile, histological examination alleviated that captopril + SNX remarkably inhibited renal injury, including tubular disorder, inflammatory cell infiltration and fibrosis. They down-regulated the serum levels of BUN and Cr, protein expression of IL-1ß, NF-κB, Bax, Cyt c, caspase 3, 8 and 9 in kidney tissues and significantly increased the levels of Bcl-2 in kidney tissues compared with monotherapy group. CONCLUSION: The combinatorial treatment of SNX and captopril lowered blood pressure through adjusting NO/NOS, ET-1 and dyslipidemia profile. Furthermore, this treatment alleviated the kidney damage via reducing the release of inflammatory factors and the expression of apoptotic markers. Therefore, these results provided a rationale for future clinical use of SNX combined with captopril in antihypertensive and protecting renal functions in hypertension.