Sensitive detection of H2S based on Ce doped ZnCo2O4 hollow microspheres at low working temperature.

In order to develop a highly efficient H2S gas sensor at low working temperature, in this work, a kind of novel Ce-doped ZnCo2O4 hollow microspheres (Ce/ZnCo2O4 HMSs) were successfully synthesized using a template-free one-pot method, showing a sensitive response toward H2S. The microstructure and morphology of the material were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The gas-sensing performance of the composite was investigated, showing that the ZnCo2O4 doped with 6 mol% Ce had the highest response to 20 ppm H2S at a low operating temperature of 160 °C with a response value of 67.42, which was about 2 times higher than that of original ZnCo2O4. The prepared Ce/ZnCo2O4 HMS sensor in response to H2S exhibited a linear range of 0.1-200 ppm with a low detection limit of 0.1 ppm under the conditions of ambient humidity of 45% and ambient temperature of 20 °C. Meanwhile, it also possessed good selectivity, repeatability and reproducibility. The response value of the sensor decreased by 5.32% after 7 months of continuous monitoring of H2S in an atmospheric environment of a pig farm, indicating that the sensor had a long-term stability and continuous service life with important application prospects.

Synthesis and evaluation for anti-HCoV-OC43 activity of novel aloperine derivatives with different core structures / 药学学报

In this study, we designed and synthesized 12 novel aloperine derivatives with different core structures. Among them, compound 3 with a ten-membered ring core was obtained through a special ring expansion reaction after γ-H Huffman elimination of quaternary ammonium salt, and the structure was verified by X-single crystal diffraction. Furthermore, their antiviral activity against human β-coronavirus HCoV-OC43 was evaluated by CCK-8 assay. Quaternary ammonium salt 2a and 3 had a good inhibitory effect against HCoV-OC43, and 2a had the highest anti-HCoV-OC43 activity with an EC50 values of 3.77 μmol·L-1 and a SI value of over 53.1. Schrӧdinger molecular docking results showed that both 2a and 3 might display their anti-HCoV-OC43 activity by directly acting on host TMPRSS2 and SR-B1. The results expanded the structural types of endocyclic aloperine and the function against coronavirus, and provided useful scientific data for the development of pharmaceutical applications of these compounds.

Traditional Chinese medicine syndrome differentiation of coronavirus disease 2019 patients / 第二军医大学学报

Objective To explore the rule of traditional Chinese medicine (TCM) syndrome differentiation of coronavirus disease 2019 (COVID-19) patients. Methods The symptoms of 756 cases with COVID-19 in Guanggu Branch of Maternity and Child Healthcare Hospital of Hubei Province were collected by cross sectional survey. The incidence rates of the symptoms were recorded by frequency method at different courses of the disease: prodromal stage (onset), middle stage (7-30 days), and later stage (>30 days). The common symptoms (incidence rate>5.0%) were analyzed by systematic clustering. With expert experience, the rule of TCM syndrome differentiation of COVID-19 patients was summarized. Results Fever (52.25%, 395 cases), cough (43.25%, 327 cases), asthenia (27.25%, 206 cases), chest distress (26.72%, 202 cases), asthma (17.59%, 133 cases) and expectoration (5.03%, 38 cases) were the most common symptoms in the prodromal stage (756 cases) of the disease, which were clustered into one category except expectoration, indicating the pathogenesis of both lung and body surface suppressed by dampness. In the middle stage (383 cases), the 19 common symptoms including greasy fur (64.49%, 247 cases), yellow fur (43.86%, 168 cases), thick fur (40.21%, 154 cases), cough (34.73%, 133 cases), red tongue (32.38%, 124 cases), poor stool (25.85%, 99 cases), asthma (25.33%, 97 cases), asthenia (25.07%, 96 cases), poor appetite (23.76%, 91 cases), bitterness of mouth (14.36%, 55 cases), dry fur (12.01%, 46 cases), purple tongue (12.01%, 46 cases), perspiration (11.49%, 44 cases), constipation (10.18%, 39 cases), white phlegm (8.62%, 33 cases), insomnia (7.31%, 28 cases), nausea (7.05%, 27 cases), diarrhea (6.79%, 26 cases) and yellow phlegm (6.27%, 24 cases), were clustered into three groups, indicating the pathogenesis of damp-heat accumulation, obstruction of lung and spleen by dampness, and dryness due to dampness-heat. In the later stage (373 cases), the 13 common symptoms including greasy fur (50.94%, 190 cases), asthenia (39.41%, 147 cases), cough (37.80%, 141 cases), red tongue (33.78%, 126 cases), asthma (32.17%, 120 cases), perspiration (23.86%, 89 cases), dry mouth (22.79%, 85 cases), poor appetite (20.11%, 75 cases), poor stool (19.30%, 72 cases), bitterness of mouth (15.01%, 56 cases), white phlegm (10.72%, 40 cases), palpitation (8.31%, 31 cases) and little fur (8.04%, 30 cases), were clustered into two groups, indicating the pathogenesis of deficiency of Qi and Yin with residual dampness, and deficiency of lung Qi and spleen Qi with residual dampness. Conclusion The TCM syndromes of COVID-19 patients in different stages have its own typical characteristics, with a regular change from exterior to interior, from dampness to dampness-heat and from excess to deficiency..

[Wavelength Variable Selection Method in Near Infrared Spectroscopy Based on Discrete Firefly Algorithm].

Taking into consideration of the large size of near-infrared spectral data, the spectral data has to be compressed to reduce the computational complexity of the established spectral calibration model and improve accuracy and robustness of the model. Near Infrared Spectroscopy wavelength variable selection method based on discrete firefly algorithm is presented. First, the Monte Carlo method was used to exclude outliers, and Kennard-Stone method was chosen for the selection of calibration set and prediction set. General firefly algorithm was discretized, by improving the attractiveness of adaptive formula, increasing traction weights in mobile formula and so on. In order to adapt to the effects of discretization and optimize algorithm, elitist strategy was added in the discrete firefly algorithm, to accelerate the convergence rate. The optimum value of the DFA algorithm parameters was found in the experiment. With wavelength variables selection based on discrete firefly algorithm, succinic acid concentration of the fermentation broth partial least squares NIR calibration model was built, which was compared with genetic algorithm method. The results showed that the correlation coefficient of calibration set (R2c) of PLS calibration model based on discrete wavelengths firefly algorithm is 0.986, RMSEC of which is 0.409. Correlation coefficient of prediction set (R2p) is 0.969 while RMSEP is 0.458. It is superior to full spectrum modeling and calibration model using genetic algorithm method. DFA shows superiority of the near-infrared spectral data filtering.

Molecular cloning, characterization and expression of the energy homeostasis-associated gene in piglet.

The energy homeostasis-associated (Enho) gene encodes a secreted protein, adropin, which regulates the expression of hepatic lipogenic genes and adipose tissue peroxisome proliferator-activated receptor γ, a major regulator of lipogenesis. In the present study, the porcine (Sus scrofa) homologue of the Enho gene, which was named pEnho, was amplified by reverse transcriptase polymerase chain reaction (RT-PCR) using oligonucleotide primers derived from in silico sequences. The gene sequence was submitted into the GenBank of NCBI, and the access number is GQ414763. The pEnho encodes a protein of 76 amino acids which shows 75% similarity to Homo sapiens adropin. The expression profile of pEnho in tissues (liver, muscle, anterior jejunum, posterior jejunum, and ileum) was determined by quantitative real-time RT-PCR. pEnho was localized on porcine chromosome 10 and no introns were found. In conclusion, pEnho was cloned and analysed with the aim of increasing knowledge about glucose and lipid metabolism in piglets and helping to promote the health and growth of piglets through adropin regulation.

Monosodium L-Glutamate and Dietary Fat Differently Modify the Composition of the Intestinal Microbiota in Growing Pigs.

BACKGROUND: The Chinese have been undergone rapid transition to a high-fat diet-consuming lifestyle, while monosodium L-glutamate (MSG) is widely used as a daily food additive. It has been reported that fat alters the composition of intestinal microbiota. However, little information is available on the effects of oral MSG on intestinal microbiota, and no study was done focusing on the interaction effect of fat and MSG with respect to intestinal microbiota. The present study thus aimed to determine the effects of MSG and/or fat on intestinal microbiota, and also to identify possible interactions between these two nutrients. METHODS: Four iso-nitrogenous and iso-caloric diets were provided to growing pigs. The microbiota from jejunum, ileum, cecum, and colon were analyzed. RESULTS: Our results show that both MSG and fat clearly increased the intestinal microbiota diversity. MSG and fat modified the composition of intestinal microbiota, particularly in the colon. Both MSG and fat promoted the colonization of microbes related to energy extraction in gastrointestinal tract via different ways. MSG promoted the colonization of Faecalibacterium prausnitzii and Roseburia, while fat increased the percentage of Prevotella in colon and other intestinal segments. CONCLUSION: Our results will help to understand how individual or combined dietary changes modify the microbiota composition to prevent obesity.

Expression, purification, and antibacterial activity of bovine lactoferrampin-lactoferricin in Pichia pastoris.

Bovine lactoferrampin (LFA) and bovine lactoferricin (LFC) are two antimicrobial peptides located in the N(1) domain of bovine lactoferrin. The bactericidal activity of the fused peptide LFA-LFC is stronger than that of either LFA or LFC. The high cost of peptide production from either native digestion or chemical synthesis limits the clinical application of antimicrobial peptides. The expression of recombinant peptides in yeast may be an effective alternative. In the current study, the expression, purification, and antibacterial activity of LFA-LFC using the Pichia pastoris expression system are reported. The linearized expression vector pPICZaA-LFA-LFC was transformed into P. pastoris KM71 by electroporation, and positive colonies harboring the target genes were screened out and used for fermentation. The recombinant LFA-LFC peptide was purified via two-step column chromatography and identified by tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The results indicate that P. pastoris is a suitable system for secreting LFA-LFC. The fermentation supernate and the purified LFA-LFC show high antimicrobial activities. The current study is the first to report on the expression and purification of LFA-LFC in P. pastoris and may have potential practical applications in microbial peptide production.

Tryptophan metabolism in animals: important roles in nutrition and health.

L-Tryptophan is a nutritionally essential amino acid for monogastric animals and preweaning ruminants because it cannot be synthesized in the body. Besides serving as a building block for proteins, tryptophan is a critical nutrient for the functions of nervous and immune systems. Over the past decades, much attention has been directed to study the role of tryptophan as a limiting amino acid in mammalian and avian nutrition. However, emerging evidence from recent studies shows that tryptophan and its metabolites (e.g., serotonin (5-hydroxytryptamine, 5-HT) and melatonin)) can regulate feed intake, reproduction, immunity, neurological function, and anti-stress responses. Additionally, tryptophan may modulate gene expression and nutrient metabolism to impact whole-body homeostasis in organisms. Thus, adequate intake of this amino acid from the diet is crucial for growth, development, and health of animals and humans.

Laser Doppler flowmeter study on regional cerebral blood flow in early stage after standard superficial temporal artery-middle cerebral artery bypass surgery for moyamoya disease / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Standard superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery is an effective treatment for moyamoya disease, but recent evidence suggests that postoperative cerebral hyperperfusion can occur. In this study, the trendline of changes in regional cerebral blood flow (rCBF) after surgery were continually monitored near the site of anastomosis in order to investigate both the efficacy of the procedure for improving rCBF and the possible risk of hyperperfusion.</p><p><b>METHODS</b>Standard STA-MCA bypass surgery was performed on 13 patients. rCBF was measured continually using laser Doppler flowmetry (LDF) until the 5th day after the operation with the LDF probe implanted adjacent to the area of the anastomosis. The trendline of rCBF changes postoperatively was recorded for the analysis performed using SPSS 13.0.</p><p><b>RESULTS</b>The baseline LDF value of cortical rCBF was (84.68 + or - 14.39) perfusion unit (PU), which was linear relative to absolute perfusion volume before anastomosis and (88.90 + or - 11.26) PU immediately after anastomosis (P > 0.05). The value changed significantly from before to after anastomosis (P < 0.05); it was (417.72 + or - 21.35) PU on the 1st day after surgery, and (358.99 + or - 18.01) PU, (323.46 + or - 17.38) PU, (261.60 + or - 16.38) PU and (375.72 + or - 18.45) PU on the following 4 days, respectively. The rCBF decreased gradually from the 2nd day until the 4th postoperative day, but still was at a high level (P < 0.05). However, on the 5th postoperative day the rCBF increased again to the second highest level, which was significantly different compared with the baseline value (P < 0.05), but not significantly different compared with the values on the other 4 days (P > 0.05).</p><p><b>CONCLUSIONS</b>STA-MCA anastomosis improves the cerebral blood supply significantly in the early stage after surgery, however, the risk of symptomatic hyperperfusion may exist, which may possibly occur on the 1st day and 5th day after surgery. A LDF is useful for postoperative monitoring for both the efficacy of bypass and possible risk of neurologic deterioration or bleeding from hyperperfusion.</p>

Purification and properties of alkaline phosphatase from porcine kidney / 医学研究生学报

Objective: For preparing the reference material of alkaline phosphatase(ALP), the purification and properties of ALP from porcine kidney were studied. Methods: The ALP purification procedure included isolation microvillus of porcine kidney cortices by solubilization the membrance-binding enzymes with 1-butanol, precipitation with ammonium sulfate, chromatography on DEAE-Sephacel,ConA-Sepharose,Sephadex G-200 and a immuno-affinity column of anti-GGT antibodies. Results: The purified enzyme had a specific activity of 402 kU/g protein at 37℃and was almost free of contaminating enzymes. The apparent Michaelis constants was 1.35 mmol/L, and the optimum pH was 10.40. Conclusion: The kinetic properties of the preparation were very close to those of the enzyme present in the human serum, The product was suitable as enzyme preparation for producing the enzyme reference material.

Study on purification and properties of lactate dehydrogenase from human erythrocyte / 临床检验杂志

Objective To preparing the reference material(RM) of lactate dehydrogenase(LD),we purification of LD from human erythrocyte(RBC)and studied its properties.Methods Using a modified procedure which including complete hemolysis of the RBC,hydroxyapatite treatment,(NH4)2 SO 4 Precipitation,CM- Sephadex C 50,Sephadex G100 and 5'- AMP- Sepharose 4B affinity chromatography.Results The purified LD has a sepecific activity of 163.0 kU/g protein.It is almost free of contaminating enzymes.Two corresponding bands were observed on both PAG plates stained for either protein or LD activity after electrophresis had been done.The apparent Michaelis constants were of 1.000 and 0.179 mmol/L for L-lactate and NAD and of 0.119 mmol/L 0.062 mmol/L for pyruvate and NADH respectively.Conclusion The final purified LD was found to be very similar to that in human serum in catalytic properties.It is intended to be a fundament to prepare a RM for the measurement of LD.