Effects of Monascus purpureus on ripe Pu-erh tea in different fermentation methods and identification of characteristic volatile compounds.

The present study aimed to explore the key volatile compounds (VCs) that lead to the formation of characteristic flavors in ripe Pu-erh tea (RIPT) fermented by Monascus purpureus (M. purpureus). Headspace solid-phase microextraction coupled with gas chromatography/mass spectrometry (HS-SPME-GC-MS), orthogonal partial least square-discriminant analysis (OPLS-DA) were employed for a comprehensive analysis of the VCs present in RIPT fermented via different methods and were further identified by odor activity value (OAV). The VCs 1,2-dimethoxybenzene, 1,2,3-trimethoxybenzene, (E)-linalool oxide (pyranoid), methyl salicylate, linalool, ß-ionone, ß-damascenone were the key characteristic VCs of RIPT fermented by M. purpureus. OAV and Gas chromatography-olfactometry (GC-O) further indicated that ß-damascenone was the highest contribution VCs to the characteristic flavor of RIPT fermented by M. purpureus. This study reveals the specificities and contributions of VCs present in RIPT under different fermentation methods, thus providing new insights into the influence of microorganisms on RIPT flavor.

The Characteristic Aroma Compounds of GABA Sun-Dried Green Tea and Raw Pu-Erh Tea Determined by Headspace Solid-Phase Microextraction Gas Chromatography-Mass Spectrometry and Relative Odor Activity Value.

We aim to improve the product quality of GABA raw Pu-erh tea during development and processing. In this study, headspace solid-phase microextraction gas chromatography-mass spectrometry technology combined with relative odor activity evaluations was used to compare the volatile compounds of GABA sun-dried green tea and GABA raw Pu-erh tea. Sensory evaluation showed a higher aroma score of GABA raw Pu-erh tea than that of GABA sun-dried green tea, with significant differences in aroma type and purity. A total of 147 volatile compounds of 13 categories were detected, which differed in composition and quantity between the two teas. 2-Buten-1-one,1-(2,6,6-trimethyl-1,3-cyclohexadien-1-yl)-,(E)- and beta.-myrcene largely contributed to the aroma formation of both teas. Five volatile compounds were screened as potential markers for tea aroma. Metabolic pathway analysis showed that monoterpenoid biosynthesis may be beneficial to the formation of flowery and fruity aromas in the teas. We suggest that the findings of this study may provide important guidance for the processing and optimization of GABA tea.

Cu-Catalyzed decarboxylative annulation of N-substituted glycines with 3-formylchromones: synthesis of functionalized chromeno[2,3-b]pyrrol-4(1H)-ones.

A novel protocol was developed for preparing functionalized chromeno[2,3-b]pyrrol-4(1H)-ones 3 (CMPOs) from 3-formylchromones with N-substituted glycine derivatives. The method entailed decarboxylative annulation of the acyl group of 3-formylchromones by simply heating a mixture of substrates 1-2 and toluene oxidized by 2-di-tert-butyl peroxide (DTBP) and catalyzed by CuBr. As a result, a series of CMPOs 3 were produced via a cascade reaction. This protocol can be used to synthesize functionalized CMPOs via combinatorial and parallel syntheses in a one-pot reaction rather than a tedious multi-step reaction.

Research on antibody changes and nucleic acid clearance in COVID-19 patients treated with convalescent plasma.

PURPOSE: To investigate changes in the production of IgM and IgG antibodies and the negative transformation of viral nucleic acids in COVID-19 patients after convalescent plasma therapy, and also to discuss the clinical therapeutic effect, so as to provide a basis for the treatment of COVID-19 using specific antibodies. METHODS: The convalescent plasma of recovered patients from COVID-19 was used to treat other patients, and the levels of antibodies IgM and IgG and the nucleic acid genes ORF1ab and N in the patients were tested regularly for statistical comparison and analysis. RESULTS: In general, the Ct value and concentration of IgM and IgG antibodies in the plasma infusion group were significantly higher (1-3 times higher) than those in the non-plasma infusion group, respectively, but these differences were not significant (P>0.05). However, the content of antibodies in severe patients in the plasma transfusion group was significantly higher than those in the non-plasma transfusion group at discharge, the results being statistically significant (P<0.05). CONCLUSIONS: The application of convalescent plasma significantly increases the antibody content in severe and critical inpatients, effectively enhances immune function, accelerates the clearance of virus and the nucleic acid negative conversion rate, and significantly promotes early improvement in COVID-19 patients.

Transcription factor CsDOF regulates glutamine metabolism in tea plants (Camellia sinensis).

Glutamine plays a critical role in ammonium assimilation, and contributes substantially to the taste and nutritional quality of tea. To date, little research has been done on glutamine synthesis in tea plants. Here, a zinc finger protein CsDOF and a glutamine synthetase (GS)-encoding gene CsGS2 from tea plant (Camellia sinensis cv 'Shuchazao') were characterized, and their role in glutamine biosynthesis was determined using transient suppression assays in tea leaves and overexpression in Arabidopsis thaliana. The expression patterns of CsDOF and CsGS2, the GS activity and the glutamine content of photosynthetic tissues (leaf and bud) were significantly induced by shade. Suppressing the expression of CsDOF resulted in downregulated expression of CsGS2 and reduction of the leaf glutamine content. Moreover, in CsDOF-silenced plants, the expression of CsDOF and the glutamine content under shade treatment were higher than in natural light. The glutamine content and CsGS2 transcript level were also decreased in tea leaves when CsGS2 was suppressed, while they were higher under shade treatment than in natural light in CsGS2-silenced plants. In addition, the glutamine content and GS2 transcript level were increased when CsDOF and CsGS2 was overexpressed in Arabidopsis thaliana, respectively. In binding analyses, CsDOF directly bound to an AAAG motif in the promoter of CsGS2, and promotes its activity. The study shed new light on the molecular mechanism by which CsDOF activates CsGS2 gene expression and contributes to glutamine biosynthesis in tea plants.

IL-6 and INF-γ levels in patients with brucellosis in severe epidemic region, Xinjiang, China.

BACKGROUND: The incidence of brucellosis, which is caused by the Brucella species of bacteria, is rapidly rising worldwide; however, few studies have investigated the immune response to this pathogen and clinical biochemical features. In this paper, we examined the levels of various cytokines and inflammatory factors as well as clinical course characteristics in patients with brucellosis, in order to provide evidence for the diagnosis, assessment, and prognosis of this infectious disease. METHODS: A total of 191 brucellosis inpatients (50 acute cases and 141 chronic cases), as well as 60 healthy control subjects, were included in the analysis. We investigated changes in the levels of six cytokines (IL-4, IL-6, IL-10, IL-17, TNF-α, INF-γ) and related clinical biochemical markers in patients with acute and chronic brucellosis in Xinjiang, China. Possible factors were statistically analyzed using the t test, χ2 test, z test and a multivariate logistic stepwise regression test. RESULTS: We found that IL-4, IL-6, IL-10, IL-17, IFN-γ, and TNF-α levels were higher in those with brucellosis than in controls (P <  0.05). With regard to disease progression, procalcitonin (PCT) and C-reactive protein (CRP) levels were significantly higher in those with an acute infection compared to chronic cases (P <  0.05). We found that the expression of all six cytokines tested was closely related to the degree of brucellosis using univariate logistic regression; however, only IL-6 and INF-γ levels were independent factors associated with the severity of brucellosis. CONCLUSIONS: Assessing cytokine levels in patients with acute and chronic brucellosis is not only useful for detecting the immune response, but can also be indicative of the severity of brucellosis. In particular, we propose IL-6 and INF-γ levels may be useful independent predictive factors in the clinical evaluation and diagnosis of brucellosis.

Electrochemical Conversion of Nitrogen Trifluoride as a Gas-to-Solid Cathode in Li Batteries.

Nonaqueous metal-gas batteries have emerged as a growing family of primary and rechargeable batteries with high capacities and energy densities. We herein report a high-capacity primary Li-gas battery that uses a perfluorinated gas, nitrogen trifluoride (NF3), as the cathode reactant. Gravimetric capacities of ∼1100 and 4000 mAh/gC are achieved at 25 and 55 °C, respectively (at 20 mA/gC), with discharge voltages up to 2.6 V vs Li/Li+. NF3 reduction occurs by a 3e-/NF3 process, yielding polycrystalline lithium fluoride (LiF) on a carbon cathode. The detailed electrochemical NF3 conversion mechanism is proposed and supported by solid- and liquid-phase characterization and theoretical computation, revealing the origin of observed discharge overpotentials and elucidating the significant contribution of N-F bond cleavage. These findings indicate the value of exploring fluorinated gas cathodes for primary batteries; moreover, they open new avenues for future targeted electrocatalyst design and cathode materials synthesis applications benefiting from conformal coatings of LiF.

Optical method for automated measurement of glass micropipette tip geometry.

Many experimental biological techniques utilize hollow glass needles called micropipettes to perform fluid extraction, cell manipulation, and electrophysiological recordings For electrophysiological recordings, micropipettes are typically fabricated immediately before use using a "pipette puller", which uses open-loop control to heat a hollow glass capillary while applying a tensile load. Variability between manufactured micropipettes requires a highly trained operator to qualitatively inspect each micropipette; typically this is achieved by viewing the pipette under 40-100x magnification in order to ensure that the tip has the correct shape (e.g., outer diameter, cone angle, taper length). Since laboratories may use hundreds of micropipettes per week, significant time demands are associated with micropipette inspection. Here, we have automated the measurement of micropipette tip outer diameter and cone angle using optical microscopy. The process features repeatable constraint of the micropipette, quickly and automatically moving the micropipette to bring its tip into the field of view, focusing on the tip, and computing tip outer diameter and cone angle measurements from the acquired images by applying a series of image processing algorithms. As implemented on a custom automated microscope, these methods achieved, with 95% confidence, ±0.38 µm repeatability in outer diameter measurement and ±5.45° repeatability in cone angle measurement, comparable to a trained human operator. Accuracy was evaluated by comparing optical pipette measurements with measurements obtained using scanning electron microscopy (SEM); optical outer diameter measurements differed from SEM by 0.35 ± 0.36 µm and optical cone angle measurements differed from SEM by -0.23 ± 2.32°. The algorithms we developed are adaptable to most commercial automated microscopes and provide a skill-free route to rapid, quantitative measurement of pipette tip geometry with high resolution, accuracy, and repeatability. Further, these methods are an important step toward a closed-loop, fully-automated micropipette fabrication system.

Overnutrition and maternal obesity in sheep pregnancy alter the JNK-IRS-1 signaling cascades and cardiac function in the fetal heart.

Maternal obesity in pregnancy predisposes offspring to insulin resistance and associated cardiovascular disease. Here, we used a well-established sheep model to investigate the effects of maternal obesity on cardiac functions. Multiparous ewes were assigned to a control (CON) diet [100% of National Research Council (NRC) recommendations] or an obesogenic (OB) diet (150% of NRC recommendations) from 60 d before conception to necropsy on d 135 of pregnancy. Fetal blood glucose and insulin were increased (P<0.01, n=8) in OB (35.09+/-2.03 mg/dl and 3.40+/-1.43 microU/ml, respectively) vs. CON ewes (23.80+/-1.38 mg/dl and 0.769+/-0.256 microU/ml). Phosphorylation of AMP-activated protein kinase (AMPK), a cardioprotective signaling pathway, was reduced (P<0.05), while the stress signaling pathway, p38 MAPK, was up-regulated (P<0.05) in OB maternal and fetal hearts. Phosphorylation of c-Jun N-terminal kinase (JNK) and insulin receptor substrate-1 (IRS-1) at Ser-307 were increased (P<0.05) in OB fetal heart associated with lower downstream PI3K-Akt activity (P<0.05), indicating impaired cardiac insulin signaling. Although OB fetal hearts exhibited a normal contractile function vs. CON fetal hearts during basal perfusion, they developed an impaired heart-rate-left-ventricular-developed pressure product in response to high workload stress. Taken together, fetuses of OB mothers demonstrate alterations in cardiac PI3K-Akt, AMPK, and JNK-IRS-1 signaling pathways that would predispose them to insulin resistance and cardiac dysfunction.