Search

The ultra-low thermal expansion coefficient α makes the Fe-Ni Invar alloys useful in various applications. Their low strength and low Curie temperature Tc are, however, limiting factors. Interestingly, some Fe-based bulk metallic glasses (BMGs), with inherent high strength, exhibit the clear Invar effect. In particular, the (Fe71.2B24Y4.8)96Nb4 BMG has the lowest α among Fe-based BMGs, but it unfortunately also has the lowest Tc. In this work, silicon was added into this alloy with the aim to elevate Tc while maintaining a low α. It was found that when silicon partially substituted boron, Tc did not increase significantly but α did, which is not ideal. On the other hand, when silicon partially substituted yttrium and niobium and especially niobium, Tc increased significantly while α did not, which is close to the ideal scenario. When 3% of niobium was substituted by silicon, Tc reached the maximum value of 296 °C while α remained a low value of 7.4 × 10−6/°C. Comparing to the Fe-Ni Invar alloy, although this BMG has an inferior α, it has much higher Tc (+115 °C) and strength (∼9 times), presenting a potential for application as a new Invar material with moderate (low) thermal expansion, high operating temperature, and high strength. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Thymus is an immune organ in which pathological changes may cause autoimmune diseases, including myasthenia gravis (MG). Recent studies have focused on Toll-like receptor 4 (TLR4) signaling as the cause of such changes. In our previous study, an imbalance of T helper 17 (Th17) cells and T regulatory (Treg) cells was found in MG thymoma. These results suggest the involvement of TLR4 in the pathogenesis of thymoma MG via an alteration of the Th17/Treg balance. Here, we aimed to assess whether the TLR4-MyD88-NF-κB pathway is upregulated in MG thymoma and its relationship with Th17/Treg cells. PATIENTS AND METHODS: We collect thymoma samples from 54 patients with or without MG, detecting the expression level of TLR4, MyD88, and NF-κB in thymoma tissues. Next, we established an in vitro experiment of coculturing thymoma cells with CD4+ T cells and detected the differentiation of Th17 cells and Treg cells and their marker protein, retinoid-related orphan receptor gamma t (ROR't) and forkhead transcription factor 3 (Foxp3). RESULTS: We found TLR4, MyD88, and NF-κB expressed more in MG thymoma compared with simple thymoma. After the transwell coculturing, we observed an imbalance of Th17/Treg cells after TLR4 stimulation. CONCLUSIONS: TLR4 is stimulated in thymoma, causing an increase of Th17 cells and a decrease of Treg cells, namely an imbalance of Th17/Treg cells, resulting in MG. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The aim of this study was to explore the association between TP53 gene polymorphisms (rs8068934 A>G and rs218698 C>T) and chronic lymphocytic leukemia (CLL). PATIENTS AND METHODS: CLL patients who received treatment in our hospital were enrolled in this study as the disease group. Meanwhile, healthy subjects were taken as the control group. Peripheral blood samples were collected to detect TP53 gene polymorphisms at rs8068934 and rs218698, and the haplotype analysis was performed. The expression of TP53 was detected via reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Furthermore, the survival conditions were analyzed. RESULTS: The allele distribution at rs8068934 (p=0.046) and rs218698 (p=0.028) of TP53 gene was different between control group and disease group. A allele frequency at rs8068934 and T allele frequency at rs218698 were significantly higher in disease group (p<0.05). The genotype distribution at rs218698 of TP53 gene in disease group was also different from that in control group (p=0.038). The results demonstrated that CC genotype frequency in disease group was significantly lower than that in control group (p<0.05). Besides, the distribution of dominant model at rs8068934 (p=0.042) and recessive model at rs218698 (p=0.033) in disease group exhibited remarkable differences from control group, in which AA+AG frequency (dominant model) at rs8068934 and CC+CT frequency (recessive model) at rs218698 in disease group were significantly higher. Meanwhile, the distribution of AT (p=0.029) and GC (p=0.007) haplotypes at rs8068934 and rs218698 in disease group was evidently different from that in control group. The results indicated that disease group showed significantly higher frequency of AT haplotype and lower frequency of GC haplotype (p<0.05). Moreover, TP53 gene polymorphisms at rs8068934 were significantly associated with the levels of white blood cells (WBC) (p=0.000) and platelets (PLT) (p=0.035). Patients with GG genotype had significantly higher level of WBC, while those with AG genotype showed significantly lower level of PLT (p<0.05). TP53 gene polymorphisms at rs218698 were associated with the level of red blood cells (RBC) (p=0.000). Patients with CT genotype had a remarkably lower level of RBC (p<0.05). There were significant correlations of TP53 gene polymorphisms at rs8068934 (p=0.000) and rs218698 (p=0.000) with the expression of TP53. The expression of TP53 was lower in people with AA genotype at rs8068934 but higher in people with TT genotype at rs218698 (p<0.05). Furthermore, TP53 gene polymorphisms at rs8068934 (p=0.000) and rs218698 (p=0.000) were markedly associated with patients' survival. CONCLUSIONS: TP53 polymorphisms are significantly correlated with the occurrence and progression of CLL. [ABSTRACT FROM AUTHOR]

OBJECTIVE: In this study, the regulatory mechanism of miR-22-3p/AKT3 in the development of Wilms' tumor (WT) was investigated. PATIENTS AND METHODS: Twenty-seven pairs of surgical tumor specimens and adjacent normal tissues were obtained from Jining No. 1 People's Hospital. The expression level of miR-22-3p in WT tissues and cell lines was measured by quantitative RT-PCR. MTT and transwell assays were performed to analyze cell proliferation and invasion in WT. The relationship between miR-22-3p and AKT3 was verified by a Dual-Luciferase assay. The protein expression of AKT3 was evaluated by Western blotting analysis. RESULTS: MiR-22-3p was downregulated and AKT3 was upregulated in WT. Functionally, overexpression of miR-22-3p inhibited cell proliferation and invasion in WT. Moreover, miR-22-3p directly targets AKT3. The knockdown of AKT3 suppressed cell proliferation and invasion in WT. In addition, upregulation of AKT3 restored the tumor suppressive effect of miR-22-3p in WT. CONCLUSIONS: MiR-22-3p inhibits the proliferation and invasion of WT cells by downregulating AKT3, indicating that miR-22-3p may be developed as a new biomarker for the diagnosis of WT. [ABSTRACT FROM AUTHOR]

The increasing consumer demand for less processed and more natural food products - while improving those products' quality, safety, and shelf-life - has raised the necessity of chemical preservative replacement. Biopreservation refers to extended storage life and enhanced safety of foods using the natural microflora and (or) their antibacterial products. Chitinolytic enzymes are of biotechnological interest, since their substrate, chitin, is a major structural component of the cell wall of fungi, which are the main cause of the spoilage of food and raw plant material. Among the several organisms, many bacteria produce chitinolytic enzymes, however, this behaviour is not general. The chitinase activity of the lactic acid bacteria is scarcely known and studied. The aim of the present study was to select Lactobacillus strains that have genes encoding chitinase, furthermore, to detect expressed enzymes and to characterise their chitinase activity. Taking into consideration the importance of chitin-bindig proteins (CBPs) in the chitinase activity, CBPs were also examined. Five Lactobacillus strains out of 43 strains from 12 different species were selected by their chitinase coding gene. The presence of the chitinase and chitin-biding protein production were confirmed, however, no chitinolytic activity has been identified. [ABSTRACT FROM AUTHOR]

OBJECTIVE: This meta-analysis aims to clarify the effect of IL-17 polymorphisms on the susceptibility to GCa in the Chinese population. MATERIALS AND METHODS: Relevant pieces of literature were searched in PubMed, Web of School, VIP, and CNKI using the key words as "IL-17, gastric/stomach cancer" or "IL-17 polymorphisms, gastric/stomach cancer susceptibility". The odds ratio (OR) and 95% confidence interval (CI) in the selected studies were calculated using RevMan5.3 and STATA12.0. RESULTS: A total of 12 investigations reporting mutations in IL-17A rs2275913 and IL-17F rs763780 were enrolled. There were 11 studies reporting rs2275913 G>A, involving 3299 cases of GCa patients and 3339 cases of healthy controls. The random-effects model was performed since the heterogeneity test results of the recessive genetic model (GG&GA vs. AA) and the allelic model (G vs. A) of IL-17A rs2275913 G>A were I2>66%/p=0.001. Meanwhile, the dominant genetic model (GG vs. GA&AA) and the super-dominant genetic model (GA vs. GG&AA) of IL-17A rs2275913 G>A were I2< 50%/p>0.05, and the fixed-effects model was used. The meta-analysis showed that IL-17A rs2275913 G>A was positively correlated with GCa susceptibility under four genetic models (p<0.05). Five studies reporting IL-17F rs763780 T>C were enrolled, including 2535 cases of GCa patients and 2402 cases of healthy controls. The heterogeneity test showed that, except for the super-dominant genetic model, the p-value was <0.00001 in the dominant, recessive, and allelic models, and their I2 values were 87%, 88%, and 93%, respectively. Hence, a random-effects model was selected. IL-17F rs763780 T>C was positively correlated with GCa susceptibility under the super-dominant genetic model (p=0.003), rather than the other three models (p>0.05). CONCLUSIONS: IL-17A rs2275913 G>A polymorphism contributes to susceptibility to GCa in the dominant, recessive, allelic, and super-dominant models. Meanwhile, IL-17F rs763780 T>C polymorphism is positively correlated with GCa susceptibility in the super-dominant model. [ABSTRACT FROM AUTHOR]

OBJECTIVE: By establishing osteoporosis (OP) model in rats, the specific regulatory effect of simvastatin on promoting the differentiation of mesenchymal stem cells (MSCs) into osteoblasts through the bone morphogenetic protein 2 (BMP-2)/Smads signaling pathway was investigated. MATERIALS AND METHODS: A total of 45 Sprague-Dawley rats were selected to establish the OP model by performing ovariectomy. The rats were divided into OP model group (OP group, n=15), 10-7 mmol/L simvastatin treatment group (SIM group, n=15), and normal control group (Control group, n=15). After the experimental period, the enzyme-linked immunosorbent assay (ELISA) was applied to observe the serum levels of tumor necrosis factor-alpha (TNF-a), interleukin-6 (IL-6), and IL-1. Reverse Transcription-Polymerase Chain Reaction (RT-PCR) was adopted to detect the contents of the differentiation-associated genes [runt-related transcription factor 2 (RUNX2) and Osterix (Osx)]. Later, the bone marrow MSCs (BMSCs) were selected and divided into Control group, 10-7 mol/L simvastatin group (SIM group), and osteoinduction medium group (OM group). Cell morphology in each group was observed. The Cell Counting Kit-8 (CCK-8) was performed to determine the proliferation activity of BMSCs. ELISA was performed to measure the level of alkaline phosphatase (ALP). RT-PCR was conducted to examine the levels of key differentiation-associated gene RUNX2 and those in BMP-2/Smads pathway. Moreover, the Western blotting was adopted to analyze the expressions of RUNX2 and genes in BMP-2/Smads pathway. RESULTS: The serum levels of TNF-a, IL-6, and IL-1 in OP group were remarkably higher than those in the Control group, and their levels in the SIM group were close to those in the Control group. The elevated messenger ribonucleic acid (mRNA) levels of the key differentiation-associated factors RUNX2, osteoprotegerin (OPG), osteopontin (OPN), and Osx were observed in the SIM group. In vitro cell culture revealed that the cells were in a favorable growth status in the SIM group and OM group, mostly manifesting in fusiform or spindle shape, and proliferated rapidly. In addition, the ALP level notably increased in the two groups compared with that in the Control group (p<0.05). Both SIM group and OM group had evidently higher mRNA expression levels of RUNX2, OPG, OPN, and Osx than those in the Control group (p<0.05), consistent with the expression trends of the genes in BMP-2/Smads pathway. The Western blotting indicated that the expression levels of RUNX2 and genes in BMP-2/Smads pathway in the SIM group were significantly higher than those in the Control group. CONCLUSIONS: Simvastatin can promote the differentiation of MSCs into osteoblasts in the OP rat model through the BMP-2/Smads signaling pathway. [ABSTRACT FROM AUTHOR]

Photocatalytic degradation of chlorophenols (CPs) has been attracting an increasing attention lately. In the paper, TiO2/H3PW12O40/Ag composite film was prepared by sol-gel method with programmed heating hydrothermal technology and spin coating technique to treat CPs. Direct photolysis of five CPs was performed according to the pseudo-first-order kinetics model, in which the photolysis rate of PCP was faster than that of the others under the simulated solar light. The results of mineralization indicated that the aromatic ring in PCP was difficult to be broken down via direct photolysis. By TiO2/H3 PW12O40 /Ag composite film, photocatalytic degradation efficiency elevated due to the enhancement of the quantum efficiency and visible-light absorption in comparison with direct photolysis as well as other reaction systems (TiO2 /H3 PW12 O40 film and TiO2 film), and the mineralization of PCP increased to 75.70%. The initial degradation rate (r0) was in the following order as PCP (0.158 mg·L-1·min-1) > 4-CP (0.144 mg·L-1·min- 1) > 2,4-DCP (0.014 mg·L-1·min-1) > 2,4,6-TCP (0.047 mg·L-1·min-1) > 2-CP (0.038 mg·L-1·min-1), confirming TiO2/H3PW12O40/Ag composite film as new catalyst to be more effective at removing for CPs. [ABSTRACT FROM AUTHOR]

The deformation of [0001]-oriented ZnO nanorods with hexagonal cross sections under uniaxial tensile loading is analyzed through molecular statistical thermodynamics (MST) simulations. The focus is on the size dependence of mechanical behavior in ZnO nanorods with diameters ranging from 1.95 to 17.5 nm. An irreversible phase transformation from the wurtzite (P63mc space group) structure to a tetragonal structure (P42/mnm space group) occurs during the tensile loading process. Young’s modulus before the transformation demonstrates a size dependence consistent with what is observed in experiments. A stronger size dependence of response is seen after the transformation and is attributed to the polycrystalline nature of the transformed structure. A comparison of the MST and molecular dynamics (MD) methods shows that MST is 60 times faster than MD and yields results consistent with the results of MD. [ABSTRACT FROM AUTHOR]

Magnetization and neutron diffraction measurements on polycrystalline BaCu[O.sub.2+x] revealed a combination of magnetic behaviors. The [Cu.sub.6] ring clusters and [Cu.sub.18] sphere clusters in this compound had ferromagnetic ground states with large spins 3 and 9, respectively. The [Cu.sub.6] rings ordered antiferromagnetically below the Neel temperature [T.sub.N] = 15 ± 0.5 kelvin, whereas the [Cu.sub.18] spheres remained paramagnetic down to 2 kelvin. The ordered moment below [T.sub.N] was 0.89(5) Bohr magnetons per Cu in the [Cu.sub.6] rings, demonstrating that quantum fluctuation effects are small in these atomic clusters. The [Cu.sub.18] clusters are predicted to exhibit ferromagnetic intercluster order below about 1 kelvin., The strong antiferromagnetic (AF) coupling between the Cu spins in the Cu[O.sub.2] planes of the undoped parent compounds of the high transition temperature cuprate superconductors (1) results from an indirect [...]