Improving Wear Resistance and Corrosive Resistance of Cemented Carbide for Mud Pulser Rotor by Deep Cryogenic Treatment.

Cemented carbide used in the rotor of a mud pulser is subjected to the scouring action of solid particles and corrosive mud media for a long time, which causes abrasive wear and electrochemical corrosion. To improve the wear and corrosive resistance of cemented carbide, samples with different cobalt content (WC-5Co, WC-8Co, and WC-10Co) receive deep cryogenic treatment (DCT) at -196 °C for 2.5 h. An optical metalloscope (OM) and X-ray diffractometer (XRD) are used to observe the phase changes of cemented carbides, and the XRD is also used to observe the change in residual stress on the cemented carbide's surface. A scanning electron microscope (SEM) is used to characterize the wear and electrochemical corrosion surface microstructure of cemented carbides (untreated and DCT). The results show that the DCT promotes the precipitation of the η phase, and the diffraction peak of ε-Co tends to intensify. Compared with the untreated, the wear rates of WC-5Co, WC-8Co, and WC-10Co can be reduced by 14.71%, 37.25%, and 41.01% by DCT, respectively. The wear form of the cemented carbides is mainly the extrusion deformation of Co and WC shedding. The precipitation of the η phase and the increase in WC residual compressive stress by DCT are the main reasons for the improvement of wear resistance. The electrochemical corrosion characteristic is the dissolution of the Co phase. DCT causes the corrosion potential of cemented carbide to shift forward and the corrosion current density to decrease. The enhancement of the corrosion resistance of cemented carbide caused by DCT is due to the Co phase transition, η phase precipitation, and the increase in the compressive stress of cemented carbide.

Characterization of novel loci controlling seed oil content in Brassica napus by marker metabolite-based multi-omics analysis.

BACKGROUND: Seed oil content is an important agronomic trait of Brassica napus (B. napus), and metabolites are considered as the bridge between genotype and phenotype for physical traits. RESULTS: Using a widely targeted metabolomics analysis in a natural population of 388 B. napus inbred lines, we quantify 2172 metabolites in mature seeds by liquid chromatography mass spectrometry, in which 131 marker metabolites are identified to be correlated with seed oil content. These metabolites are then selected for further metabolite genome-wide association study and metabolite transcriptome-wide association study. Combined with weighted correlation network analysis, we construct a triple relationship network, which includes 21,000 edges and 4384 nodes among metabolites, metabolite quantitative trait loci, genes, and co-expression modules. We validate the function of BnaA03.TT4, BnaC02.TT4, and BnaC05.UK, three candidate genes predicted by multi-omics analysis, which show significant impacts on seed oil content through regulating flavonoid metabolism in B. napus. CONCLUSIONS: This study demonstrates the advantage of utilizing marker metabolites integrated with multi-omics analysis to dissect the genetic basis of agronomic traits in crops.

Vitamin C deficiency induces hypoglycemia and cognitive disorder through S-nitrosylation-mediated activation of glycogen synthase kinase 3ß.

Vitamin C (VC, l-ascorbic acid) is an essential nutrient that plays a key role in metabolism and functions as a potent antioxidant in regulating the S-nitrosylation and denitrosylation of target proteins. The precise function of VC deprivation in glucose homeostasis is still unknown. In the absence of L-gulono-1,4-lactone oxidoreductase, an essential enzyme for the last step of VC synthesis, VC deprivation resulted in persistent hypoglycemia and subsequent impairment of cognitive functions in female but not male mouse pups. The cognitive disorders caused by VC deprivation were largely reversed when these female pups were given glucose. VC deprivation-induced S-nitrosylation of glycogen synthase kinase 3ß (GSK3ß) at Cys14, which activated GSK3ß and inactivated glycogen synthase to decrease glycogen synthesis and storage under the feeding condition, while VC deprivation inactivated glycogen phosphorylase to decrease glycogenolysis under the fasting condition, ultimately leading to hypoglycemia and cognitive disorders. Treatment with Nω-Nitro-l-arginine methyl ester (l-NAME), a specific inhibitor of nitric oxide synthase, on the other hand, effectively prevented S-nitrosylation and activation of GSK3ß in female pups in response to the VC deprivation and reversed hypoglycemia and cognitive disorders. Overall, this research identifies S-nitrosylation of GSK3ß and subsequent GSK3ß activation as a previously unknown mechanism controlling glucose homeostasis in female pups in response to VC deprivation, implying that VC supplementation in the prevention of hypoglycemia and cognitive disorders should be considered in the certain groups of people, particularly young females.

Moringa oleifera leaf extracts protect BMSC osteogenic induction following peroxidative damage by activating the PI3K/Akt/Foxo1 pathway.

OBJECTIVE: We aimed to investigate the therapeutic effects of Moringa oleifera leaf extracts on osteogenic induction of rat bone marrow mesenchymal stem cells (BMSCs) following peroxidative damage and to explore the underlying mechanisms. METHODS: Conditioned medium was used to induce osteogenic differentiation of BMSCs, which were treated with H2O2, Moringa oleifera leaf extracts-containing serum, or the phosphatidyl inositol-3 kinase (PI3K) inhibitor wortmannin, alone or in combination. Cell viability was measured using the MTT assay. Cell cycle was assayed using flow cytometry. Expression levels of Akt, phosphorylated (p)Akt, Foxo1, and cleaved caspase-3 were analyzed using western blot analysis. The mRNA levels of osteogenesis-associated genes, including alkaline phosphatase (ALP), collagen І, osteopontin (OPN), and Runx2, were detected using qRT-PCR. Reactive oxygen species (ROS) and malondialdehyde (MDA) levels, as well as superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), and ALP activity were detected using commercially available kits. Osteogenic differentiation capability was determined using alizarin red staining. RESULTS: During osteogenic induction of rat BMSCs, H2O2 reduced cell viability and proliferation, inhibited osteogenesis, increased ROS and MDA levels, and decreased SOD and GSH-PX activity. H2O2 significantly reduced pAkt and Foxo1 expression, and increased cleaved caspase-3 levels in BMSCs. Additional treatments with Moringa oleifera leaf extracts partially reversed the H2O2-induced changes. Wortmannin partially attenuated the effects of Moringa oleifera leaf extracts on protein expression of Foxo1, pAkt, and cleaved caspase-3, as well as mRNA levels of osteogenesis-associated genes. CONCLUSION: Moringa oleifera leaf extracts ameliorate peroxidative damage and enhance osteogenic induction of rat BMSCs by activating the PI3K/Akt/Foxo1 pathway.

COVID-19: Antiviral Agents, Antibody Development and Traditional Chinese Medicine.

The World Health Organization (WHO) has declared coronavirus disease 2019 (COVID-19) is the first pandemic caused by coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Currently, there is no effective anti-SARS-CoV-2 drug approved worldwide for treatment of patients with COVID-19. Therapeutic options in response to the COVID-19 outbreak are urgently needed. To facilitate the better and faster development of therapeutic COVID-19 drugs, we present an overview of the global promising therapeutic drugs, including repurposing existing antiviral agents, network-based pharmacology research, antibody development and traditional Chinese medicine. Among all these drugs, we focus on the most promising drugs (such as favipiravir, tocilizumab, SARS-CoV-2 convalescent plasma, hydroxychloroquine, Lianhua Qingwen, interferon beta-1a, remdesivir, etc.) that have or will enter the final stage of human testing-phase III-IV clinical trials.

Thioredoxin mitigates H2 O2 -induced inhibition of myogenic differentiation of rat bone marrow mesenchymal stem cells by enhancing AKT activation.

Thioredoxin (Trx) is a hydrogen acceptor of ribonucleotide reductase and a regulator of some enzymes and receptors. It has been previously shown that significantly elevated levels of Trx expression are associated with the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs), but it is not clear how Trx regulates the effects of hydrogen peroxide (H2 O2 ) on myogenic differentiation of BMSCs. Here, we report that rat BMSCs treated with a high dose (150 µm) of H2 O2 exhibited a significant reduction in viability, cell cycling, and superoxide dismutase and glutathione peroxidase levels, and an increase in reactive oxygen species and malondialdehyde levels, which was accompanied by reductions in protein kinase B activation and forkhead Box O1, myogenic differentiation 1 and myogenin expression during myogenic differentiation. Furthermore, treatment with recombinant human Trx significantly mitigated the effects of H2 O2 on the myogenic differentiation of BMSCs, and this was abrogated by cotreatment with wortmannin [a specific phosphatidylinositol 3-kinase inhibitor]. In summary, our results suggest that treatment with recombinant human Trx mitigates H2 O2 -induced oxidative stress and may promote myogenic differentiation of rat BMSCs by enhancing phosphatidylinositol 3-kinase/protein kinase B/forkhead Box O1 signaling.

[Mechanism of different processed products of Codonopsis pilosula on spleen deficiency rats based on 1H-NMR metabonomics].

Based on1 H-NMR metabonomics,the effects of Codonopsis pilosula,rice-fried C. pilosula and honey-fried C. pilosula on spleen-asthenia rats were compared,and the mechanism was discussed in this study. The rat model of spleen deficiency was established by weight-bearing swimming and fasting every other day. The effects of different processed products of C. pilosula on the body weight and swimming time of rats were observed. At the end of administration,the gastrocnemius muscle of the right leg of rats was collected and detected by1 H-NMR,and the mechanism of different processed products of C. pilosula in improving spleen deficiency was preliminarily investigated by multivariate statistical analysis. The results showed that C. pilosula,honey-fried C. pilosula and rice-fried C. pilosula could significantly prolong the swimming time( P<0. 05). There was no significant difference in the body weight of rats with spleen deficiency. The results of metabonomics showed that honey-processed C. pilosula could significantly decrease levels of leucine,isoleucine,alanine,acetate,glutamate,succinate,anserine,dimethylamine,dimethylglycine,creatine,phosphorylcholine,glycerophosphorylcholine,taurine,inosine,fumate,hypoxanthine and lactate,but increase levels of glucose,glycine,compared with model group. Therefore,honey-fried C. pilosula has the best efficacy on spleen deficiency syndrome in rats by regulating glycometabolism,amino acid metabolism,lipid metabolism and nucleotide metabolism.

Radix Tetrastigma hemsleyani flavone exhibits antitumor activity in colorectal cancer via Wnt/ß-catenin signaling pathway.

BACKGROUND: Radix Tetrastigma hemsleyani flavone (RTHF) is extracted from a traditional Chinese medicinal herb T. hemsleyani, which is conventionally used as a folk medicine for its anti-inflammation activity and antiviral activity. In this study, the effects of RTHF on inhibiting malignant biological properties in colorectal cancer (CRC) were evaluated by conducting both in vitro and in vivo experiments, and the underlying mechanism was investigated. MATERIALS AND METHODS: Cell Counting Kit-8, colony formation, and flow cytometry assays were performed to evaluate the proliferation of RTHF-treated colon tumor cells. Migration and invasion capacities were also tested by cell wound scratch assay and Transwell invasion assay. Moreover, the antitumor effects of RTHF on azoxymethane/dextran sulfate sodium-induced colitis-related CRC were investigated in C57BL/6 mice. In addition, Western blot and/or quantitative reverse transcription polymerase chain reaction analysis were used to evaluate the expressions of Lgr5, Cyclin D1, c-Myc, and E-cadherin. RESULTS: These experiments showed that RTHF could decrease the cell growth kinetics and clone-forming capacity. RTHF could also dose dependently induce cell cycle arrest at G0/G1 phase and inhibit epithelial-mesenchymal transition process. Furthermore, downregulation of ß-catenin activation and downstream protein expression were detected in CRC cells after being treated with RTHF. RTHF daily gavage suppressed the number and size of CRC in mice and inhibited Lgr5 and Cyclin D1 expressions in tumor tissue. CONCLUSION: In conclusion, RTHF treatment inhibits colorectal tumor growth, decreases Wnt/ß-catenin pathway activity, and downregulates target genes' expression.

Effects of ω-3 Fatty Acids on Toll-like Receptor 4 and Nuclear Factor κB p56 in the Pancreas of Rats With Severe Acute Pancreatitis.

OBJECTIVES: The aims of this study were to determine the effects of ω-3 fatty acids (ω-3FAs) on the Toll-like receptor 4 (TLR4)/nuclear factor κB p56 (NF-κBp56) signaling pathway in the pancreas of rats with severe acute pancreatitis (SAP). METHODS: Sixty-four Sprague-Dawley rats were randomly divided into 4 groups: the control, SAP-saline, SAP-soybean oil, and SAP-ω-FA groups. Severe acute pancreatitis was induced by the retrograde infusion of sodium taurocholate into the pancreatic duct. The expression of TLR4 and NF-κBp56 in the pancreas was evaluated by immunohistochemistry and Western blot analysis. The levels of the proinflammatory cytokines interleukin 6 and tumor necrosis factor α in the pancreas were measured by enzyme-linked immunosorbent assays. RESULTS: Toll-like receptor 4, NF-κBp56, and inflammatory cytokine expression in the pancreas was increased significantly in the SAP group compared with that in the control group (P < 0.05), but was significantly decreased in the ω-3FA group compared with that in the soybean oil group at 24 and 48 hours (P < 0.05). CONCLUSIONS: Our results suggest that during the initial stage of SAP ω-3FAs could efficiently lower the inflammatory response by activating the TLR4/NF-κBp56 signaling pathway.

Upregulation of arginase activity contributes to intracellular ROS production induced by high glucose in H9c2 cells.

Arginase is upregulated in some tissues under diabetes states. Arginase can compete with nitroxide synthase (NOS) for the common substrate L-arginine and thus increases oxidative stress by NOS uncoupling. We want to analyze whether arginase is upregulated and contribute to oxidative stress in H9c2 cells during high glucose treatment. H9c2 cells were cultured in normal or high glucose DMEM. Arginase activity increased in parallel with increased cell death and oxidative stress. Arginase inhibitor N ω-hydroxy-nor-l-arginine (nor-NOHA) and NOS inhibitor N ω-nitro-l-arginine methyl ester (L-NAME) could reverse these effects. Despite of upregulated NOS activity, NO production was impaired which could be preserved by nor-NOHA, suggesting a decreased substrate availability of NOS due to increased arginase activity. L-arginine supplementation decreased superoxide production while it could not protect cells from death. Upregulated arginase activity in H9c2 treated with high glucose can cause NOS uncoupling and subsequently reactive oxygen species augmentation and cell death. These findings suggest that arginase will be a novel therapeutic target for treatment of diabetic cardiomyopathy.

[Treating irritable bowel syndrome by wuling capsule combined pinaverium bromide: a clinical research].

OBJECTIVE: To evaluate the efficacy and safety of wuling Capsule combined with Pinaverium Bromide in treatment of irritable bowel syndrome (IBS). METHODS: Sixty-four IBS patients were randomized into two groups, the treatment group and the control group, 32 in each group. Patients in the treatment group took wuling Capsule (0. 33 g/capsule, 3 times per day) and Pinaverium Bromide (50 mg/tablet, one tablet each time, 3 times per day) , while those in the control group only took Pinaverium Bromide (50 mg/tablet, one tablet each time, 3 times per day). The therapeutic course for all was 6 weeks. IBS symptom score questionnaire, IBS-Quality of Life (IBS-QOL) , Self-Rating Depression Scale (SDS) , and Self-Rating Anxiety Scale (SAS) were assessed before and after treatment. Adverse reactions were also observed. RESULTS: The improvement of abdominal pain, stool frequency, and stool properties, as well as changing rates of integrals were significantly higher in the treatment group than in the control group (P <0. 05). The improvement of dysphoria, body image, concerns for health, and dietary restriction of IBS-QOL, as well as changing rates of integrals were significantly higher in the treatment group than in the control group (P <0. 05). The improvement of SDS and SAS, as well as changing rates of integrals were significantly higher in the treatment group than in the control group (P <0. 05). No severe adverse reaction occurred in either group. CONCLUSION: Combination therapy of wuling Capsule and Pinaverium Bromide could improve abdominal pain and defecation, attenuate depression and anxiety of IBS patients with higher safety.

[Efficacy of Shugan Yiyang Capsules combined with sertraline on premature ejaculation].

OBJECTIVE: To observe the clinical effect of Shugan Yiyang Capsules combined with sertraline in the treatment of premature ejaculation (PE). METHODS: We randomly assigned 192 PE patients to receive sertraline hydrochloride 50 mg qd (control group, n = 96) or sertraline hydrochloride 50 mg qd plus Shugan Yiyang Capsules at the dose of 4 capsules tid ( combination therapy group, n = 96) , both for 6 weeks. We compared the intravaginal ejaculatory latency time (IELT) and Chinese Index of Premature Ejaculation ( CIPE) scores between the two groups of patients before and after medication and at 6 weeks after drug withdrawal. RESULTS: Compared with the baseline, the IELT was significantly increased after 6 weeks of medication in the combination therapy group ([1.41 ± 0.53] vs [6.69 ± 3.56] min, P < 0.05) and the control group ([1.43 ± 0.48] vs [5.37 ± 2.91] min, P < 0.05), and so was the CIPE score in the former (9. 80 ± 2.06 vs 21.62 ± 4.76, P < 0.05) and the latter group ([9.41 ± 1.97] vs [20.85 ± 4.83] , P < 0.05). In comparison with the pre-medication indexes, the IELT ([3.77 ± 1.63] min) and CIPE score (16.92 ± 3.37) of the combined therapy group were remarkably improved at 6 weeks after drug withdrawal (P < 0.05), but not those of the control ([1.19 ± 1.34] min and 10.59 ± 2.38, P > 0.05). CONCLUSION: Shugan Yiyang Capsules combined with sertraline have a definite and lasting effect on premature ejaculation.

N-arylated-lactam-type iminosugars as new immunosuppressive agents: discovery, optimization, and biological evaluation.

We have previously described the discovery of N-alkylated iminosugars that showed immunosuppressive activity both in vitro and in vivo. Herein, we report the synthesis and biological evaluation of N-arylated lactam-type iminosugar derivatives. The synthesis started from simple monosaccharides and featured a Buchwald-Hartwig coupling reaction to construct the key N-aryl connection, thereby providing a highly diverse compound library. Structure-activity relationship studies, guided by a mouse-spleen-proliferation assay, led to the identification of 'hit' compound 12 f. Subsequently, the systematic modification of compound 12 f afforded compounds 21 h, 21 k, 21 n, 21 t, and 21 x with improved activities (IC50 =12-30 µM) and low Jurkat cytotoxicities (IC50 >100 µM). These new compounds also inhibited the secretion of IFN-γ and IL-4, which are hallmark cytokines of Th1 and Th2 cells, respectively. This work demonstrated that the N-arylated iminosugar structure represents a new scaffold with immunosuppressive activity.

Increase in viral yield in eggs and MDCK cells of reassortant H5N1 vaccine candidate viruses caused by insertion of 38 amino acids into the NA stalk.

BACKGROUND: The H5N1 subtype of highly pathogenic avian influenza viruses has spread to over 63 countries in Asia, Europe, and Africa and has become endemic in poultry. Since 2004, vaccination against H5N1 influenza has become common in domestic poultry operations in China. Most influenza vaccines have been produced in embryonated chicken eggs. High yield is the essential feature of a good vaccine candidate virus. OBJECTIVE: Therefore, the large-scale manufacture of such a vaccine requires that the viral yield of H5N1 reassortant vaccine viruses in eggs and MDCK cells be increased. METHODS: We generated two sets of reassortant H5N1 viruses based on backbone viruses A/Chicken/F/98 (H9N2) and A/Puerto Rico/8/34 (H1N1) using reverse genetics. The HAs and NAs of the reassortants were derived from the three epidemic H5N1 strains found in China. We compared the replication properties of these recombinant H5N1 viruses in embryonated chicken eggs and MDCK cells after inserting either 20 or 38 amino acids into their NA stalks. RESULTS: In this study, we demonstrated that inserting 38 amino acids into the NA stalks can significantly increase the viral yield of H5N1 reassortant viruses in both embryonated chicken eggs and MDCK cells, while inserting only 20 amino acids into the same NA stalks does not. Hemagglutinin inhibition testing and protection assays indicated that recombinant H5N1 viruses with 38 aa inserted into their NA stalks had the same antigenicity as the viruses with wt-NA. CONCLUSION: These results suggest that the generation of an H5N1 recombinant vaccine seed by the insertion of 38 aa into the NA stalk may be a suitable and more economical strategy for the increase in viral yield in both eggs and MDCK cells for the purposes of vaccine production.