Reversible switching between two common protein folds in a designed system using only temperature.

Naturally occurring metamorphic proteins have the ability to interconvert from one folded state to another through either a limited set of mutations or by way of a change in the local environment. Here, we show in a designed system that it is possible to switch reversibly between two of the most common monomeric folds employing only temperature changes. We demonstrate that a latent 3α state can be unmasked from an α/ß-plait topology with a single V90T amino acid substitution, populating both forms simultaneously. The equilibrium between these two states exhibits temperature dependence, such that the 3α state is predominant (>90%) at 5 °C, while the α/ß-plait fold is the major species (>90%) at 30 °C. We describe the structure and dynamics of these topologies, how mutational changes affect the temperature dependence, and the energetics and kinetics of interconversion. Additionally, we demonstrate how ligand-binding function can be tightly regulated by large amplitude changes in protein structure over a relatively narrow temperature range that is relevant to biology. The 3α/αß switch thus represents a potentially useful approach for designing proteins that alter their fold topologies in response to environmental triggers. It may also serve as a model for computational studies of temperature-dependent protein stability and fold switching.

Enhanced therapeutic potential of Flotillins-modified MenSCs by improve the survival, proliferation and migration.

Menstrual blood-derived endometrial stem cells (MenSCs) have attracted increasing interest due to their excellent safety, and lack of ethical dilemma as well as their ability to be periodically obtained in a noninvasive manner. However, although preclinical research as shown the therapeutic potential of MenSCs in several diseases, their poor cell survival and low engraftment at disease sites reduce their clinical efficacy. Flotillins (including Flot1 and Flot2) are implicated in various cellular processes, such as vesicular trafficking, signal transduction, cell proliferation, migration and apoptosis. In this study, we aimed to determine the effects of Flotillins on MenSCs survival, proliferation and migration. Our experimental results show that MenSCs were modified to overexpress Flot1 and/or Flot2 without altering their intrinsic characteristics. Flot1 and Flot2 co-overexpression promoted MenSC viability and proliferation capacity. Moreover, Flot1 or Flot2 overexpression significantly promoted the migration and inhibited the apoptosis of MenSCs compared with the negative control group, and these effects were stronger in the Flot1 and Flot2 gene co-overexpression group. However, these effects were significantly reversed after Flot1 and/or Flot2 knockdown. In conclusion, our results indicate that Flot1 and Flot2 overexpression in MenSCs improved their proliferation and migration and inhibited their apoptosis, and this might be an effective approach to improve the efficiency of cell-based therapies.

Dynamics of carbon storage driven by land use/land cover transformation in coal mining areas with a high groundwater table: A case study of Yanzhou Coal Mine, China.

Intensive anthropogenic activities have led to drastic changes in land use/land cover (LULC) and impacted the carbon storage in high-groundwater coal basins. In this paper, we conduct a case study on the Yanzhou Coalfield in Shandong Province of China. We further classify waterbodies by using the Google Earth Engine (GEE) to better investigate the process of LULC transformation and the forces driving it in four periods from 1985 to 2020 (i.e., 1985-1995, 1995-2005, 2005-2015, and 2015-2020). We modeled the spatiotemporal dynamics of carbon storage by using InVEST based on the transformation in LULC and its drivers, including mining (M), reclamation (R), urbanization and village relocation (U), and ecological restoration (E). The results indicate that carbon storage had depleted by 19.69 % (321099.06 Mg) owing to intensive transformations in LULC. The area of cropland shrank with the expansion of built-up land and waterbodies, and 56.31 % of the study area underwent transitions in land use in the study period. U was the primary driver of carbon loss while E was the leading driver of carbon gain. While the direct impact of M on carbon loss accounted for only 5.23 % of the total, it affected urbanization and led to village relocation. R led to the recovery of cropland and the reclamation of water for aquaculture, which in turn improved the efficiency of land use. However, it contributed only 2.09 % to the total increase in carbon storage. Numerous complicated and intertwined processes (211) drove the changes in carbon storage in the study area. The work here provides valuable information for decision-makers as well as people involved in reclamation and ecological restoration to better understand the link between carbon storage and the forces influencing it. The results can be used to integrate the goals of carbon sequestration into measures for land management.

Moderate Salinity Stress Affects Rice Quality by Influencing Expression of Amylose- and Protein-Content-Associated Genes.

Salinity is an environmental stress that severely impacts rice grain yield and quality. However, limited information is available on the molecular mechanism by which salinity reduces grain quality. In this study, we investigated the milling, appearance, eating and cooking, and nutritional quality among three japonica rice cultivars grown either under moderate salinity with an electrical conductivity of 4 dS/m or under non-saline conditions in a paddy field in Dongying, Shandong, China. Moderate salinity affected rice appearance quality predominantly by increasing chalkiness rate and chalkiness degree and affected rice eating and cooking and nutritional quality predominantly by decreasing amylose content and increasing protein content. We compared the expression levels of genes determining grain chalkiness, amylose content, and protein content in developing seeds (0, 5, 10, 15, and 20 days after flowering) of plants grown under saline or non-saline conditions. The chalkiness-related gene Chalk5 was up-regulated and WHITE-CORE RATE 1 was repressed. The genes Nuclear factor Y and Wx, which determine amylose content, were downregulated, while protein-content-associated genes OsAAP6 and OsGluA2 were upregulated by salinity in the developing seeds. These findings suggest some target genes that may be utilized to improve the grain quality under salinity stress conditions via gene-pyramiding breeding approaches.

Hawthorn Fruit (Crataegus spp.) Polysaccharides Exhibit Immunomodulatory Activity on Macrophages via TLR4/NF-κB Signaling Activation.

The immunostimulatory effects and the involved molecular mechanisms of polysaccharides from hawthorn fruit (Crataegus spp.) have not been well understood. In this study, the chemical composition, monosaccharide composition, uronic acid content, and structural features of hawthorn fruit polysaccharides (HFP) and the two collected fractions were analyzed. Both AF1-2 and AF2 have pectic-like structural features rich in galacturonic acid. AF2 showed superior proinflammatory effects on macrophages which significantly increased the secretion of pro-inflammatory cytokines interleukin-1ß, interleukin-6, and tumor necrosis factor-α, but not AF1-2. AF2 was found to activate the nuclear factor-κB signaling pathway with suppressed expression of IκBα but up-regulated expression of p-IκBα and nuclear factor-κB P65. The surface binding site of AF2 on macrophage cells was characterized and toll like receptor-4 was responsible for AF2 induced activation of down-stream nuclear factor-κB signaling pathways. AF2 from hawthorn fruit could be potentially used as a natural source of immunomodulator in functional foods.

Conditioned medium of human menstrual blood-derived endometrial stem cells protects against cell inflammation and apoptosis of Npc1KO N2a cells.

Niemann-Pick disease type C1 (NPC1) is a hereditary neurodegenerative disorder caused by a mutation in the NPC1 gene. This gene encodes a transmembrane protein found in lysosomes. This disease characterized by hepatosplenomegaly, neurological impairments and premature death. Recent preclinical studies have shown promising results in using mesenchymal stem cells (MSCs) to alleviate the symptoms of NPC1. One type of MSCs, known as human menstrual blood-derived endometrial stem cells (MenSCs), has attracted attention due to its accessibility, abundant supply, and strong proliferation and regeneration capabilities. However, it remains uncertain whether the conditioned medium of MenSCs (MenSCs-CM) can effectively relieve the symptoms of NPC1. To investigate this further, we employed the CRISPR-Cas9 technique to successfully create a Npc1 gene knockout N2a cell line (Npc1KO N2a). Sanger sequencing confirmed the occurrence of Npc1 gene mutation in these cells, while western blotting revealed a lack of NPC1 protein expression. Filipin staining provided visual evidence of unesterified cholesterol accumulation in Npc1KO N2a cells. Moreover, Npc1KO N2a cells exhibited significantly decreased viability, increased inflammation, and heightened cell apoptosis. Notably, our study demonstrated that the viability of Npc1KO N2a cells was most significantly improved after being cultured by 36 h-collected MenSCs-CM for 0.5 days. Additionally, MenSCs-CM exhibited the ability to effectively reduce inflammation, counteract cell apoptosis, and ameliorate unesterified cholesterol accumulation in Npc1KO N2a cells. This groundbreaking finding establishes, for the first time, the protective effect of MenSCs-CM on N2a cells with Npc1 gene deletion. These findings suggest that the potential of MenSCs-CM as a beneficial therapeutic approach for NPC1 and other neurodegenerative diseases.

COVID-19-related secretory otitis media in the omicron era: a case series.

OBJECTIVES: Increased numbers of patients with secretory otitis media appeared in outpatient clinics after the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) Omicron pandemic; however, the relationship between SARS-CoV-2 Omicron variant infection and secretory otitis media is uncertain. METHODS: We performed tympanocentesis and used reverse transcription-polymerase chain reaction (RT-PCR) testing to examine middle ear effusion (MEE) and nasopharyngeal secretions from 30 patients with secretory otitis media associated with SARS-CoV-2 infection. RT-PCR was performed using the open reading frame 1ab and nucleocapsid protein gene kit from Shanghai Berger Medical Technology Co., Ltd., as the sole assay method, in accordance with the manufacturer's instructions. RESULTS: MEEs from 5 of the 30 patients tested positive for SARS-CoV-2, including one patient with positive results for both the nasopharyngeal secretion and MEE. We report and discuss the medical records of six patients, including these five MEE-positive patients and a MEE-negative patient. CONCLUSION: SARS-CoV-2 RNA can be detected in MEE caused by coronavirus disease 2019-related secretory otitis media even when a patient's nasopharyngeal secretion tests PCR-negative for SARS-CoV-2. The virus can remain in the MEE for a long time after SARS-CoV-2 infection.

Effect of prone trunk-extension on lumbar and lower limb muscle stiffness.

This study investigated the effect of the prone trunk extension test (PTE) on lumbar and lower limb muscle stiffness to explore the optimal angle for lumbar muscle training, understand the peripheral muscle force transmission effect, and determine the modulation strategy and interaction mode of different muscles during PTE. Twenty healthy young females were recruited for this study, and the stiffness of the erector spinae (ES), semitendinosus (ST), biceps femoris (BF), medial head of the gastrocnemius (MG), and lateral head of the gastrocnemius (LG) was measured by MyotonPRO under four angular PTE conditions (0° horizontal position, 10°, 20°, and 30°). With the increasing angle, the stiffness of ES decreased gradually, while ST and BF increased first and then decreased. The stiffness of MG and LG increased first, then decreased, then increased. There was a moderate to strong negative correlation between ES stiffness variation and ST (r = -0.819 to -0.728, p < 0.001), BF (r = -0.620 to -0.527, p < 0.05), MG (r = -788 to -0.611, p < 0.01), and LG (r = -0.616 to -0.450, p < 0.05). Horizontal PTE maximizes the activation of ES. There is a tension transfer between the ES, hamstrings, and gastrocnemius, mainly between the ES, ST, and LG. The study provides data to explore the effect of peripheral muscle force transmission and the modulation strategies of different muscles during trunk extension.

Biosynthesis of Vanillin by Rational Design of Enoyl-CoA Hydratase/Lyase.

Vanillin holds significant importance as a flavoring agent in various industries, including food, pharmaceuticals, and cosmetics. The CoA-dependent pathway for the biosynthesis of vanillin from ferulic acid involved feruloyl-CoA synthase (Fcs) and enoyl-CoA hydratase/lyase (Ech). In this research, the Fcs and Ech were derived from Streptomyces sp. strain V-1. The sequence conservation and structural features of Ech were analyzed by computational techniques including sequence alignment and molecular dynamics simulation. After detailed study for the major binding modes and key amino acid residues between Ech and substrates, a series of mutations (F74W, A130G, A130G/T132S, R147Q, Q255R, ΔT90, ΔTGPEIL, ΔN1-11, ΔC260-287) were obtained by rational design. Finally, the yield of vanillin produced by these mutants was verified by whole-cell catalysis. The results indicated that three mutants, F74W, Q147R, and ΔN1-11, showed higher yields than wild-type Ech. Molecular dynamics simulations and residue energy decomposition identified the basic residues K37, R38, K561, and R564 as the key residues affecting the free energy of binding between Ech and feruloyl-coenzyme A (FCA). The large changes in electrostatic interacting and polar solvating energies caused by the mutations may lead to decreased enzyme activity. This study provides important theoretical guidance as well as experimental data for the biosynthetic pathway of vanillin.

Quantitative proteomic analysis of tomato fruit ripening behavior in response to exogenous abscisic acid.

BACKGROUND: To determine how abscisic acid (ABA) affects tomato fruit ripening at the protein level, mature green cherry tomato fruit were treated with ABA, nordihydroguaiaretic acid (NDGA) or sterile water (control, CK). The proteomes of treated fruit were analyzed and quantified using tandem mass tags (TMTs) at 7 days after treatment, and the gene transcription abundances of differently expressed proteins (DEPs) were validated with quantitative real-time polymerase chain reaction. RESULTS: Postharvest tomato fruit underwent faster color transformation and ripening than the CK when treated with ABA. In total, 6310 proteins were identified among the CK and treatment groups, of which 5359 were quantified. Using a change threshold of 1.2 or 0.83 times, 1081 DEPs were identified. Among them, 127 were upregulated and 127 were downregulated in the ABA versus CK comparison group. According to KEGG and protein-protein interaction network analyses, the ABA-regulated DEPs were primarily concentrated in the photosynthesis system and sugar metabolism pathways, and 102 DEPs associated with phytohormones biosynthesis and signal transduction, pigment synthesis and metabolism, cell wall metabolism, photosynthesis, redox reactions, allergens and defense responses were identified in the ABA versus CK and NDGA versus CK comparison groups. CONCLUSION: ABA affects tomato fruit ripening at the protein level to some extent. The results of this study provided comprehensive insights and data for further research on the regulatory mechanism of ABA in tomato fruit ripening. © 2023 Society of Chemical Industry.

[Physicochemical properties and anti-inflammatory and immunomodulatory effects of Shengfupian polysaccharides].

In this study, the crude polysaccharides was extracted from Shengfupian and purified by Sevag deproteinization. Then, the purified neutral polysaccharide fragment was obtained by the DEAE-52 cellulose chromatography column and Sephadex G-100 co-lumn. The structure of polysaccharides was characterized by ultraviolet spectroscopy, infrared spectroscopy, ion chromatography, and gel permeation chromatography. To investigate the anti-inflammatory activity of Shengfupian polysaccharides, LPS was used to induce inflammation in RAW264.7 cells. The expression of the CD86 antibody on surface of M1 cells, the function of macrophages, and the content of NO and IL-6 in the supernatant were examined. An immunodepression model of H22 tumor-bearing mice was established, and the immunomodulatory activity of Shengfupian polysaccharides was evaluated based on the tumor inhibition rate, immune organ index and function, and serum cytokine levels. Research indicated that Shengfupian polysaccharides(80 251 Da) was composed of arabinose, galactose, glucose, and fructose with molar ratio of 0.004∶0.018∶0.913∶0.065. It was smooth and lumpy under the scanning electron microscope. In the concentration range of 25-200 µg·mL~(-1), Shengfupian polysaccharides exhibited little or no toxicity to RAW264.7 cells and could inhibit the polarization of cells to the M1 type and reduce the content of NO and IL-6 in the cell supernatant. It could suppress the phagocytosis of cells at the concentration of 25 µg·mL~(-1), while enhancing the phagocytosis of RAW264.7 cells within the concentration range of 100-200 µg·mL~(-1). The 200 mg·kg~(-1) Shengfupian polysaccharides could alleviate the spleen injury caused by cyclophosphamide, increase the levels of IL-1ß and IL-6, and decrease the level of TNF-α in the serum of mice. In conclusion, Shengfupian polysaccharides has anti-inflammatory effect and weak immunomodulatory effect, which may the material basis of Aconm Lateralis Radix Praeparaia for dispelling cold and relieving pain.

[Research progress on structure, structure-activity relationship, and biological activity of Aconiti Lateralis Radix Praeparata polysaccharides].

Aconiti Lateralis Radix Praeparata polysaccharides(AP) are a class of bioactive macromolecules extracted from the herbs of Aconiti Lateralis Radix Praeparata and its various processed products. Since the AP was first separated in 1986, its pharmacological effects include immune regulation, anti-tumor, anti-depression, organ protection, hypoglycemia, and anti-inflammatory had been found. In recent years, with the development of polysaccharide extraction, separation, and structure identification technologies, more than 20 kinds of AP have been separated from Aconiti Lateralis Radix Praeparata and its processed products, and they have ob-vious differences in relative molecular weight, monosaccharide composition, glycosidic bond, structural characteristics, and biological activities. In particular, AP may be dissolved, degraded, or allosteric under the complex processing environment of fermentation, soaking, cooking, etc., leading to the diversified structure of AP, which provides a possibility for further understanding of the structure-activity relationship of AP. Therefore, this study systematically reviewed the research progress on the structure and structure-activity relationship of AP, summarized the biological activity and potential action mechanism of AP, and discussed the technical challenges in the development and application of AP, so as to promote the quality control and further development and utilization of AP.

The type of previous abortion modifies the association between air pollution and the risk of preterm birth.

BACKGROUND: Air pollution and previous abortion have been reported to be related to preterm birth (PTB). But rare study examined the effect of air pollution on PTB risk among mothers with previous abortion. OBJECTIVE: To estimate the effect of air pollution on PTB and the potential effect modification of previous abortion on such an association in rural part of Henan province (China). METHOD: Based on National Free Preconception Health Examination Project (NFPHEP), information from the medical records of 57,337 mothers with previous abortion were obtained. An inverse distance-weighted model was used to estimate exposure levels of air pollutants. The effect of air pollution on the risk of PTB was estimated with a multiple logistic regression model. Stratified and interaction analyses were undertaken to explore the potential effect modification of previous abortion on this association. RESULTS: The risk of PTB was positively associated with exposure to levels of nitrogen dioxide (NO2; OR: 1.03; 95%CI: 1.02-1.04)], and sulfur dioxide (SO2; 1.04; 1.02-1.07), and negatively associated with ozone (O3) exposure (0.97; 0.97-0.98) during the entire pregnancy. Besides, we observed a positive effect of carbon monoxide (CO) exposure during the third trimester of pregnancy on PTB (1.14; 1.01-1.29). The type of previous abortion could modify the effect of air pollution on the PTB risk (P-interaction < 0.05). Compared with mothers with previous induced abortion, mothers with previous spontaneous abortion carried a higher risk of PTB induced by NO2, CO, and O3. CONCLUSIONS: The risk of PTB was positively associated with levels of NO2, SO2 and CO, and negatively associated with the O3 level. The types of previous abortion could modify the effect of air pollution on PTB. Mothers who had an abortion previously, especially spontaneous abortion, should avoid exposure to air pollution to improve their pregnancy outcome.

Erythropoietin and iron for anemia in HIV-infected patients undergoing maintenance hemodialysis in China: a cross-sectional study.

BACKGROUND: Anemia is a common complication of chronic kidney disease (CKD) and HIV infection. The number of people living with HIV on hemodialysis (HD) is increasing. However, there is no data about anemia and related therapies in this kind of patients in China. We aim to assess the difference in hemoglobin (Hgb) and treatments like erythropoietin and iron between HIV-HD patients and HD patients in Chengdu, China. METHODS: This cross-sectional study was conducted with data collection from January 2020 to June 2020. Thirty-four HIV-infected HD patients and thirty-five non-HIV-infected HD patients were included. Age, gender, dialysis vintage, single-pool (sp) Kt/V, Hgb, the dose of erythropoietin, ferritin, use of iron preparations, and serum albumin were collected in all patients. Time since HIV diagnosis, counts of CD4 + T cells, HIV RNA, and antiretroviral therapy for HIV infection were collected in HIV-infected patients. T-test, Mann-Whitney U test, and chi-square statistics were applied in SPSS. RESULTS: The Hgb of HIV-HD and HD groups were 105.70 (95.93-112.08) g/L and 112.00 (93.00-126.00) g/L respectively (P = 0.064). There was a statistically significant higher erythropoietin dosage used in the HIV-HD population (222.55 ± 115.47 U/kg/week) compared to the HIV-negative HD group (161.86 ± 110.31 U/kg/week) (P = 0.029). 16/34 (47.06%) HIV-HD patients and 5/35 (14.29%) HD patients were treated with iron preparations (P = 0.003). The ferritin levels were 316.50 (117.38-589.75) ng/ml and 272.70 (205.00-434.00) ng/ml in HIV-HD and HD groups respectively. CONCLUSIONS: A higher erythropoietin dosage and a higher probability of iron preparations may be required to maintain Hgb in HIV-HD patients compared with HD patients.

The developmental toxicity and transcriptome analyses of zebrafish (Danio rerio) embryos exposed to carbon nanoparticles.

Long-term and short-term exposure to carbon nanoparticles (CNPs) can affect fetal development and subsequent adverse outcomes including preterm delivery, intrauterine growth restriction, low birth weight, increased health risk linked to cardiovascular, respiratory and nervous systems in adulthood. The adverse developmental outcomes of CNPs were well known, but the underlying mechanisms remain unresolved. In this study, zebrafish embryos were treated with CNPs of 50,100,200 µg/mL and the toxic effects were observed. Using the RNA-seq analysis approach, we examined the effects of CNPs (200 µg/mL) on gene expression in zebrafish embryos exposed from 4 to 96 h-post-fertilization (hpf). We observed that CNPs-treated embryos exhibited increased malformations and decreased hatching. A total of 236 differentially expressed genes were detected by transcriptome analyses, which were associated with phototransduction, amino acid metabolism, steroid and steroid hormone biosynthesis. Transcriptome results were verified by real-time fluorescence quantitative PCR (RT-qPCR). Our results indicated that CNPs exposure was most likely to lead to differential gene changes in steroid and hormone biosynthesis pathways, thus inducing developmental toxicity such as delayed incubation of zebrafish embryos, increased malformation rate and multiple malformation phenotypes.

Increasing acid rain frequency promotes the microbial community dissimilarities of forest soil rather than agricultural soil in southern China.

Soil microbial community drives the terrestrial carbon (C) cycling by C sources metabolism (i.e., organic C decomposition), however, the microbial response to changing acid rain frequency remains less studied, thus hampering global warming projection. Here, we manipulated a simulated experiment to decipher the impact of acid rain frequency (0, 30%, and 100%) on microbial community and C sources metabolism in the agricultural and forest soils of southern China, based on the phospholipid fatty acids (PLFAs) analysis and BIOLOG method, respectively. We found that changing acid rain frequency did not affect the microbial biomass and community structure of agricultural soil during the whole experiment period, while the 30% and 100% acid rain frequencies significantly decreased the microbial biomass, and altered the microbial community structure of forest soil at the early stage. However, changing acid rain frequency did not influence the microbial C sources metabolism in the agricultural soil, but 30% acid rain frequency significantly reduced the microbial utilization of carboxylic acids in the forest soil. Moreover, increasing acid rain frequency promoted the microbial community dissimilarities of forest soil. The microbial community structure and C sources utilization of agricultural soil were significantly related to soil available phosphorus content, while that of forest soil correlated with the soil available potassium content and temperature. Changes in soil environmental condition, soil acidification parameters and soil nutrients explained most of the variance of microbial community and C sources utilization (81% and 57%, respectively) in the forest soil, whereas great uncertainties of microbial community and C sources utilization existed in the agricultural soil with the explanatory proportion being 20% and 10%, respectively. Our findings suggest that the microbial community of forest soil is more sensitive to changing acid rain frequency than that of agricultural soil in a short term. These results support the prediction of microbes-driven C cycling dynamics in specific soil ecosystems in the context of changing acid rain frequency.

[Main spicy components, mechanism and masking technology for spicy flavor of Chinese medicine: a review].

Many Chinese medicinal materials, vegetable oils and extracts, and even Chinese patent medicines are spicy, which influences the medication compliance of patients, especially children. Different from the sour, sweet, bitter, salty, and umami tastes, it is a painful sensation formed when the spicy substances stimulate the nerve endings. At the moment, there are a few studies on the spicy components and mechanism and masking technology for the spicy flavor of Chinese medicine in the pharmaceutical industry, and the findings in food science are usually taken as a reference, which fail to guide the masking of the spicy flavor in Chinese medicine preparations. According to literature research, the exterior-releasing medicine, dampness-resolving medicine, and interior-warming medicine are spicy, especially some vegetable oils and extracts. Taking Zingiberis Rhizoma and prescriptions containing this medicinal as an example, the spicy components in Chinese medicine and the structure-activity characteristics were analyzed to reveal the mechanism for the spicy flavor: spicy components activate the transient receptor potential vanilloid subfamily member 1(TRPV1). The advantages and disadvantages of separation, neutralization with sugar, and inclusion for the masking of the spicy flavor were summarized and the applicability in Chinese medicine was analyzed. Moreover, the future development direction was put forward. This study is expected to promote the development of spicy masking technology for Chinese medicine prescriptions for children.

[Comparison of odor and quality of Galli Gigerii Endothelium Corneum derived from domestic chickens and broilers].

Galli Gigerii Endothelium Corneum(GGEC) is commonly used for the clinical treatment of indigestion, vomiting, diarrhea, and infantile malnutrition with accumulation. In recent decades, omnivorous domestic chickens, the original source of GGEC, has been replaced by broilers, which may lead to significant changes in the quality of the yielding GGEC. Through subjective and objective sensory evaluation, biological evaluation, and chemical analysis, this study compared the odor and quality between GGEC derived from domestic chickens and that from broilers. The odor intensity between them was compared by odor profile analysis and it was found that the fishy odor of GGEC derived from domestic chickens was significantly weaker than that of GGEC from broilers. Headspace-solid phase microextraction-gas chromatography-triple quadrupole tandem mass spectrometry(HS-SPME/GC-QQQ-MS/MS) suggested that the overall odor-causing chemicals were consistent with the fishy odor-causing chemicals. According to the odor activity va-lue and the orthogonal partial least squares discriminant analysis(OPLS-DA) result, dimethyl trisulfide, 2-methoxy-3-isobutylpyrazine, and 2-methylisoborneol were responsible for the fishy odor(OAV≥1) and the content of fishy odor-causing chemicals in GGEC derived from broilers was 1.12-2.13 folds that in GGEC from domestic chickens. The average pepsin potency in GGEC derived from broilers was 15.679 U·mg~(-1), and the corresponding figure for the medicinal from domestic chickens was 26.529 U·mg~(-1). The results of pre-column derivatization reverse-phase high-performance liquid chromatography(RP-HPLC) assay showed that the content of total amino acids and digestion-promoting amino acids in domestic chickens-derived GGEC was 1.12 times and 1.15 times that in GGEC from broilers, and the bitter amino acid content was 1.21 times folds that of the latter. In conclusion, GGEC derived from domestic chickens had weaker fishy odor, stronger enzyme activity, higher content of digestion-promoting amino acids, and stronger bitter taste than GGEC from broilers. This study lays a scientific basis for studying the quality variation of GGEC and provides a method for identifying high-quality GGEC. Therefore, it is of great significance for the development and cultivation of GGEC as both food and medicine and breeding of corresponding varieties.

Stimulating the Reversibility of Sb2 S3 Anode for High-Performance Potassium-Ion Batteries.

Conversion-alloy sulfide materials for potassium-ion batteries (KIBs) have attracted considerable attention because of their high capacities and suitable working potentials. However, the sluggish kinetics and sulfur loss result in their rapid capacity degeneration as well as inferior rate capability. Herein, a strategy that uses the confinement and catalyzed effect of Nb2 O5 layers to restrict the sulfur species and facilitate them to form sulfides reversibly is proposed. Taking Sb2 S3 anode as an example, Sb2 S3 and Nb2 O5 are dispersed in the core and shell layers of carbon nanofibers (C NFs), respectively, constructing core@shell structure Sb2 S3 -C@Nb2 O5 -C NFs. Benefiting from the bi-functional Nb2 O5 layers, the electrochemical reversibility of Sb2 S3 is stimulated. As a result, the Sb2 S3 -C@Nb2 O5 -C NFs electrode delivers the rapidest K-ion diffusion coefficient, longest cycling stability, and most excellent rate capability among the controlled electrodes (347.5 mAh g-1 is kept at 0.1 A g-1 after 100 cycles, and a negligible capacity degradation (0.03% per cycle) at 2.0 A g-1 for 2200 cycles is delivered). The enhanced K-ion storage properties are also found in SnS2 -C@Nb2 O5 -C NFs electrode. Encouraged by the stimulated reversibility of Sb2 S3 and SnS2 anodes, other sulfides with high electrochemical performance also could be developed for KIBs.

Seasonality regulates the effects of acid rain on microbial community in a subtropical agricultural soil of Southern China.

Acid rain alters soil carbon (C) cycling by influencing the soil microbial community structure and functions. However, the response of soil microbial communities to acid rain with time and underlying mechanisms are still poorly understood. Herein, we conducted a one-year intact soil core experiment to investigate the temporal changes of soil microbial community composition and C sources metabolism under acid rain (pH 5.0, pH 4.0, and pH 3.0) in an agricultural soil of southern China. We found that pH 3.0 acid rain increased the total, bacterial, gram-positive bacterial, and actinomycetal PLFAs at the early stage, but this effect diminished with time. Conversely, the gram-negative bacterial PLFAs contents were reduced under pH 3.0 acid rain at the later stage. Interestingly, pH 5.0 acid rain increased the total, bacterial, gram-positive bacterial, and actinomycetal PLFAs contents at the later stage. In addition, pH 3.0 and pH 5.0 acid rain treatments accordingly altered the soil microbial community structure at the early and later stage. However, acid rain did not change the microbial C sources utilization pattern. The principal response curve analysis revealed that the seasonal variation exerted a greater effect on the overall variance of soil microbial community structure than the acidity of acid rain. Our results demonstrate the asynchronous response of soil microbial community structure and function, which implies that the microbial functional redundancy may exist in the subtropical agricultural soil under acid rain.