Effect of Deformation on the Corrosion Behavior of Friction Stir Welded Joints of 2024 Aluminum Alloy.

Friction stir welding (FSW) of aluminum alloys is an advanced manufacturing technology to realize lightweight bodywork. However, most studies only focus on the mechanical properties and corrosion behaviors of the welded joints. The effect of deformation on the corrosion behavior of FSWed joints is unclear. In this work, the plastic deformation behavior was characterized using uniaxial tensile tests. The effect of deformation on the corrosion behavior of a 2024 aluminum alloy nugget was studied by using a Tafel polarization curve, electrochemical impedance spectroscopy, exfoliation corrosion test, scanning electron microscopy and energy dispersive spectrometer, and transmission electron microscopy. The results show that the corrosion resistance of FSWed joints with different deformation degrees can be ranked as: 0% > 7% > 10% > 4%, and an "inflection point" appears at 7%. The corrosion potential and current density at 7% are near the values at 0%, and the 7% sample shows less corrosion rate than all other deformation samples. Only pitting and bubbling occur in the sample in 96 h. With an increase in plastic deformation, the dislocations and dislocation rings increase, there is an increase in the surrounding winding precipitates. The impurity phase is cleaved by dislocations; a reduction in the size of the impurity phase with low chemical activity can be observed, resulting in an increase in corrosion resistance. However, the transgranular and intergranular cracks appear on the 10% deformation sample. They almost always develop along the grain boundaries after initiation, making them more susceptible to corrosion.

LncRNA SND1-IT1 facilitates TGF-ß1-induced epithelial-to-mesenchymal transition via miR-124/COL4A1 axis in gastric cancer.

The transformation of tumor cells from an epithelial to a mesenchymal-like phenotype, designated as epithelial-to-mesenchymal transition (EMT), represents a key hallmark of human cancer metastasis, including gastric cancer (GC). However, a large set of non-coding RNAs have been studied for their functions that initiate or inhibit this phenotypic switch in GC cells by regulating oncogenes or tumor suppressors. In this paper, we aimed to identify lncRNA SND1-IT1, miR-124, and COL4A1 gene in the context of GC with a specific focus on their effects on transforming growth factor ß1 (TGF-ß1)-induced EMT. The study included 52 paired samples of lesion tissues and adjacent lesion-free tissues surgically resected from patients diagnosed with GC. HGC-27 cells were stimulated with exogenous TGF-ß1 (2 ng/mL). Expression of lncRNA SND1-IT1, miR-124, and COL4A1 was determined by RT-qPCR. CCK-8 assays, Transwell assays, immunoblotting analysis of EMT-specific markers, and tumor invasion markers were performed to evaluate cell viability, migration, and invasion of cultured HGC-27 cells. Luciferase activity assay was employed to examine miR-124 binding with lncRNA SND1-IT1 and COL4A1, respectively. LncRNA SND1-IT1 was upregulated in GC tissues and cells. TGF-ß1-stimulated EMT and regulated lncRNA SND1-IT1, miR-124, and COL4A1 expressions in HGC-27 cells. LncRNA SND1-IT1 knockdown tempered HGC-27 cell viability, migration and invasion. LncRNA SND1-IT1 participated in TGF-ß1-stimulated EMT in GC by sponging miR-124. MiR-124 attenuated TGF-ß1-stimulated EMT in GC by targeting COL4A1. These results primarily demonstrated TGF-ß1 can regulate cancer cell migration, invasion and stimulate EMT through the SND1-IT1/miR-124/COL4A1 axis in GC.

Preference for daily versus on-demand pre-exposure prophylaxis for HIV and correlates among men who have sex with men: the China Real-world Oral PrEP Demonstration study.

INTRODUCTION: This study explores the preference for daily versus on-demand pre-exposure prophylaxis (PrEP) among men who have sex with men (MSM) in developing countries when both regimens are available. METHODS: From 11 December 2018 to 19 October 2019, we recruited MSM for an open-label real-world PrEP demonstration study in four major cities in China. Subjects selected their preferred PrEP (oral tenofovir/emtricitabine) regimen (daily vs. on-demand) at recruitment and underwent on-site screening before initiation of PrEP. We used logistic regression to assess preference for daily PrEP and correlates. RESULTS: Of 1933 recruited MSM, the median age was 29 years, 7.6% was currently married to or living with a female; the median number of male sexual partners was four and 6.1% had used post-exposure prophylaxis (PEP) in the previous six months. HIV infection risk was subjectively determined as very high (>75%) in 7.0% of subjects, high (50% to 75%) in 13.3%, moderate (25% to 49%) in 31.5% and low or none (0% to 24%) in 48.1%. On average, participants preferred on-demand PrEP over daily PrEP (1104 (57.1%) versus 829 (42.9%)) at recruitment. In multivariable analysis, currently being married to or living with a female was associated with 14.6 percentage points lower preference for daily PrEP (marginal effect = -0.146 [95% CI: -0.230, -0.062], p = 0.001); whereas the number of male sexual partners (marginal effect = 0.003 [95% CI: 0.000, 0.005], p = 0.034) and a subjective assessment of being very high risk of HIV infection (vs. low and no risk, marginal effect size = 0.105 [95% CI: 0.012, 0.198], p = 0.027) were associated with increased preference for daily versus on-demand PrEP. Among the 1933 potential participants, 721 (37.3%) did not attend the subsequent on-site screening. Lower-income, lower education level, lower subjective expected risk of HIV infection risk and younger age positively correlated with the absence of on-site screening. CONCLUSIONS: MSM in China prefer both daily and on-demand PrEP when both regimens are provided free. Social structural factors and subjective risk of HIV infection have significant impacts on PrEP preference and use. The upcoming national PrEP guideline should consider incorporating both regimens and the correlates to help implement PrEP in China.

Dexamethasone can attenuate the pulmonary inflammatory response via regulation of the lncH19/miR-324-3p cascade.

OBJECTIVE: To investigate lncRNAs and their roles in regulating the pulmonary inflammatory response under dexamethasone (Dex) treatment. METHODS: IL-1ß (10 ng/mL) and LPS (1 µg/mL) was used to construct inflammatory cell models with A549 cells; IL-1ß performed better against LPS. Different concentrations of Dex were used to attenuate the inflammation induced by IL-1ß, and its effect was assessed via RT-PCR to detect inflammatory cytokine-related mRNA levels, including those of IKß-α, IKKß, IL-6, IL-8, and TNF-α. Furthermore, ELISA was used to detect the levels of the inflammatory cytokines TNF-α, IL-6, and IL-8. RT-PCR was used to quantify the levels of lncRNAs, including lncMALAT1, lncHotair, lncH19, and lncNeat1. LncH19 was most closely associated with the inflammatory response, which was induced by IL-1ß and attenuated by Dex. Among the lncRNAs, the level of lncH19 showed the highest increase following treatment with 1 and 10 µM Dex. Therefore, lncH19 was selected for further functional studies. LncH19 expression was inhibited by shRNA transduced with lentivirus. Cell assays for cell proliferation and apoptosis as well as RT-PCR, western blot, and ELISA for inflammatory genes were conducted to confirm the functions of lncH19. The predicted target miRNAs of lncH19 were hsa-miR-346, hsa-miR-324-3p, hsa-miR-18a-3p, hsa-miR-18b-5p, hsa-miR-146b-3p, hsa-miR-19b-3p, and hsa-miR-19a-3p. Following estimation via RT-PCR, hsa-miR-346, hsa-miR-18a-3p, and hsa-miR-324-3p showed consistent patterns in A549 NC and A549 shlncH19. An miRNA inhibitor was transfected into A549 NC and A549 shlncH19 cells, and the expression levels were determined via RT-PCR. hsa-miR-324-3p was inhibited the most compared with hsa-miR-346 and hsa-miR-18a-3p and was subjected to further functional studies. RT-PCR, ELISA, and western blotting for inflammatory gene detection were conducted to validate the functions of the target hsa-miR-324-3p. RESULTS: Treatment with 1 and 10 µM Dex could effectively attenuate the inflammatory response. During this process, lncH19 expression significantly increased (P < 0.05). Therefore, treatment with 1 µM Dex was used for further study. Under IL-1ß treatment with or without Dex, lncH19 inhibition led to an increase in cell proliferation; a decrease in cell apoptosis; an increase in the protein levels of inflammatory genes; phosphorylation of P65, ICAM-1, and VCAM-1; and increase inflammatory cytokines. Prediction of the targets of lncH19 and validation via RT-PCR revealed that miR-346, miR-18a-3p, and miR-324-3p negatively correlate with lncH19. Additionally, Dex increased the lncH19 expression but reduced that of the miRNAs. Among the miRNAs, miR-324-3p was the most markedly downregulated miRNA following treatment of miRNA inhibitors. The MTS assay and cell apoptosis assay showed that the miR-324-3p inhibitor inhibited cell proliferation and induced cell apoptosis, thereby significantly attenuating the inflammatory response, which reversed the effect of lncH19 in regulating cell proliferation and the secretion of inflammatory cytokines (P < 0.05). Therefore, lncH19 might regulate miR-324-3p in pulmonary inflammatory response under Dex treatment. CONCLUSION: Dex can attenuate the pulmonary inflammatory response by regulating the lncH19/miR-324-3p cascade.

Long noncoding RNA atlas of the inflammation caused by asthma in mice.

There is little evidence regarding the roles of long noncoding RNAs (lncRNAs) in inflammation caused by asthma. In this study, we successfully generated an asthma mouse model that was induced by ovalbumin (OVA). The effects of dexamethasone (Dex) treatment on lung tissue were investigated using pathological and biochemical methods, including Diff-Quik staining, enzyme-linked immunosorbent assay (ELISA), hematoxylin-eosin (H&E) staining, and western blotting (WB). The inflammation was effectively relieved with Dex treatment. High-throughput sequencing revealed that a total of 1490 lncRNAs were detected in lung tissue samples. Differential expression analysis revealed that the Dex group had 20 upregulated and 15 downregulated lncRNAs compared with those in the Model group. Moreover, nine differentially expressed and inflammation-related lncRNAs were verified by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). Furthermore, the regulation networks of these nine lncRNAs, their potential binding microRNA (miRNAs), and the putative target genes showed that these lncRNAs play important roles in the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway. We further identified the expression levels of three potential binding miRNAs by qRT-PCR. The results of this study contribute to a better understanding of the functions of lncRNAs in inflammation caused by asthma.

[Distribution of podophyllotoxin-loaded nanostructured lipid carriers after topical application on cervical mucosa in Tibet minipigs].

OBJECTIVE: To assess the distribution and systemic toxicity of podophyllotoxin-loaded nanostructured lipid carriers (POD-NLC) after topical application on the cervical mucosa in Tibet minipigs. METHODS: Twelve Tibet mini-pigs were randomized into test group and control group to receive topical application of 0.5% POD-NLC and 0.5% POD tincture, respectively, on the cervical mucosa. Cervical mucosal irritation, targeted distribution and systemic absorption of POD were observed at different time points within 24 h after the drug application. RESULTS: No local inflammation reaction was observed in the test group, while serious local irritations (swelling, blisters, blood blisters, erosion and ulceration) occurred in the control group. The fluorescence intensity of POD in the mucosal tissue reached the peak level at 4 h after drug application in the control group, while the POD fluorescence intensity increased slowly and reached the peak level at 16 h in the test group. The peak blood POD concentration occurred at 6 h after POD-NLC application in the test group (14.28∓0.33 ng/mL), as compared to 4 h in the control group (42.46∓0.32 ng/mL). At all the time points within 24 h, blood POD concentration remained significantly lower in the test group than in the control group (P<0.05), and the area under curve of blood POD concentration in the control group was 1.38-fold greater than that in the test group. CONCLUSION: POD-NLC allows sustained release of POD and achieves a higher POD concentration in the mucosal tissue without causing local irritation or obvious systemic toxicity in Tibet minipigs.

Subcutaneous Panniculitis-Like T-Cell Lymphoma in Children: A Review of the Literature.

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a type of skin lymphoma. Pleomorphic T-cells infiltrate the subcutaneous tissue and mimic lobular panniculitis. We report a case occurring in a 12-year-old Chinese boy who presented with multiple indolent erythematous subcutaneous nodules on both extremities without systemic symptoms. He had a protracted course of multiple erythematous subcutaneous nodules for 1 year and underwent biopsy of lesional skin for histology and T-cell receptor (TCR) gene analysis. Histopathology showed infiltration of medium to large atypical pleomorphic cells involving the subcutis with characteristic rimming of fat spaces. TCR gene rearrangement shows monoclonal rearrangements of the TCR ß and γ chains. Immunophenotypic studies showed that CD3, CD4, and CD8 were strongly and diffusely positive in lesional cells and that CD56 was focally positive. In contrast, these cells were negative for CD20, CD30, and CD68. The combined morphology, characteristic histologic features, and positive T-CR gene rearrangement supported a diagnosis of SPTCL. He is being treated with combination chemotherapy of cyclophosphamide, doxorubicin, vincristine, and prednisolone.

[The dynamic change of serum CK, CK-MB and myocardium histomorphology after exhausted exercise in rats].

OBJECTIVE: To study the dynamic changes of serum CK, CK-MB and myocardium histomorphology in different time periods after single bout and repeated exhausted exercise in rats. METHODS: The animal models of myocardial injury were established by exhausted swimming. Creatine kinase (CK), creatine kinase mass (CK-MB) activities in serum were measured immediately at 3, 6, 12, 24, 48 and 96 hours after exhausted exercise, and the dynamic changes of myocardial histopathology were examined. RESULTS: The CK, CK-MB activities were significantly increased immediately at 3, 6, 12 hours and peaked at 6 hours after single bout of exhausted exercise, meantime the degree of inflammatory cell infiltrate and strong acidophil staining were gradually increased in myocardium of rat, and the myocardial injury was most severe at 12 hours. After 1-week consecutive daily exhausted swimming, CK, CK-MB in serum were obviously increased immediately at, 3, 6, 12, 48 and 96 hours postexercise and peaked immediately and at 96 hours respectively postexercise. There were different degrees of myocardial injury in different time of recovery phase, and was most severe at 48 hours postexercise. CONCLUSION: The myocardial injury was induced by excessive exercise and/or exhausted exercise, and the resulting delayed-onset myocardial injury was further certified.

[Protective effect of puerarin on stress-induced gastric mucosal injury in rats].

OBJECTIVE: To study the protective effect of puerarin on stress-induced gastric mucosal injury in rats. METHOD: The model of gastric ulcer was established by restraint plus water-immersion stress in rats. Gastric motility was monitored by the method of "Gas Balloon". Gastric mucosal blood flow was recorded by laser-Doppler flowmetry. Colorimetric method was used to determine the content of NO and ET in gastric mucosal tissue. Meantime the pathologic changes of gastric mucosal was examined. RESULT: Puerarin could significantly attenuated gastric mucosal damage induced by water-immersion stress, inhibited gastric motility, specially decreased the index of gastric motility and percentage of gastric contraction time and numbers of violent contraction. The gastric mucosal blood flow and NO level in gastric mucosal were enhanced, while ET level was reduced by puerarin. The degree of tissue damage in gastric mucosal was also significantly attenuated after administration fo puerarin. CONCLUSION: Puerarin exerts a significant protective effect on water-immersion stress-induced gastric mucosal damage by relaxing the vessels, increasing NO level in gastric mucosal, increasing regional gastric mucosal blood flow and inhibiting gastric motility.