Search

Layered crystal Bi2O2Te has recently been found to have high electron mobility and excellent thermoelectric properties for technical applications; however, its other properties are not well studied yet. In this work, the electronic, elastic and optical properties of Bi2O2Te are systematically studied using the density functional method. The results indicate that Bi2O2Te is a narrow band gap semiconductor. The gap is formed by the Te 5p orbital at the top of the valence band and the Bi 6p orbital at the bottom of the conduction band. There are both ionic and covalent interactions within the Bi–O layers, and these layers are linked by the ionic Bi–Te bonds forming the crystal. Bi2O2Te is mechanically stable but anisotropic. It is easy to fracture along the c axis under shear stress. Its shear modulus is far smaller than its bulk modulus, so shape deformation is easier to occur than pure volume change. Its melting point is predicted to be 1284.0 K based on an empirical formula. The calculated refractive index at zero frequency reveals that Bi2O2Te is a negative uniaxial crystal with a birefringence of 0.51, making it a potential tuning material for optical application. The characteristics and origins of other optical properties are also discussed. [ABSTRACT FROM AUTHOR]

Introduction: Salivary adenoid cystic carcinoma (SACC) is a frequent type of salivary gland cancer which is characterized by slow growth but high incidence of distant metastasis. We aimed to identify therapeutic targets which are associated with metastasis of SACC.Material and Methods: Total RNA was isolated from a low metastatic SACC cell line (ACC-2) and a highly metastatic SACC cell line (ACC-M), which was screened from ACC-2 by combination of in vivo selection and cloning in vitro. Then the total RNA was subjected to microarray analysis. Differentially expressed genes (DEGs) were screened from ACC-M compared with ACC-2, followed by Gene Ontology function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Function annotation for DEGs also was performed. A protein-protein interaction network (PPI) was constructed for DEGs.Results: A total of 1128 DEGs were identified from ACC-M cells compared with ACC-2 cells. Both up- and down-regulated DEGs were enriched in different functions in biological process (BP), cellular component (CC) and molecular function (MF). Additionally, down-regulated DEGs were mainly enriched in "Apoptosis" and "Cytokine-cytokine receptor interaction" pathways which involved IFN-α1, NTRK1 and TGF-β1. In the PPI network, PIK3CA, PTPN11 and PIK3R1 had a number of nodes greater than 10.Conclusions: Transforming growth factor β1 might play a pivotal role during lung metastasis of SACC and be selected as a candidate target for treatment of metastatic SACC. IFNA1, NTRK1 and PIK3CA were also associated with tumor metastasis. [ABSTRACT FROM AUTHOR]

Polo‑like kinase 2 (PLK2) is a serine/threonine protein kinase, which has vital roles during mitosis and the centrosome cycle. In acute myeloblastic leukemia and hepatocarcinogenesis, PLK2 acts as a tumor suppressor; however, the function of PLK2 in gastric cancer remains to be elucidated. In the present study, PLK2 was overexpressed in gastric cancer tissues and three types of gastric cancer cells, SGC‑7901, MKN‑45 and BGC‑823. Transfection of SGC‑7901 gastric cancer cells with small interfering (si)RNA against PLK2 exerted no effect on the ratio of cells at different stages of the cell cycle compared with that of the untransfected and control siRNA‑transfected cells. In addition, silencing of PLK2 significantly enhanced the growth of SGC‑7901 cells through inhibiting apoptosis. Furthermore, apoptosis‑associated genes Bax and caspase 3 were found to be downregulated at the protein level. In conclusion, these results suggested that PLK2 may act as a tumor suppressor in gastric cancer, therefore indicating its therapeutic potential.

Objective: To investigate the difference in the responsiveness of intracellular free Ca2+ concentration ([Ca2+]i) to progesterone in the spermatozoa of normal fertile men and patients with unexplained infertility., Methods: Nine normal fertile men and 10 patients with unexplained infertility were selected in this study. After swim-up separation of the motile fraction and 2-hour in vitro capacitation, the spermatozoa were loaded with the fluorescent calcium indicator Fluo-3/AM (8.85 micromol/L) for 40 minutes away from the light, and then the sperm suspension was mixed with equal amount of 20% gelatin to immobilize the spermatozoa. The basal intracellular free [Ca2+]i and that induced by 10 micromol/L progesterone in the individual sperm were assessed by laser scanning confocal microscopy., Results: The infertile patients had a significantly lower basal level of [Ca2+]i in the capacitated sperm than the fertile men (P < 0.01). The sperm from the normal controls responded to progesterone by exhibiting a rapid but transient rise in [Ca2+]i, with the peak level significantly higher than the basal level (P < 0.05), while those from the infertile patients by showing a slight increase, with no significant difference between the peak and basal levels (P > 0.05). Both the peak of the progesterone-induced [Ca2+]i and its increase amplitude expressed as the difference between the peak and basal levels were significantly higher in the normal fertile group than in the infertile patients (P < 0.01)., Conclusion: The responsiveness of [Ca2+]i to progesterone is reduced in the spermatozoa of patients with unexplained infertility, which suggests a functional defect in the non-genomic sperm membrane progesterone receptor responsible for calcium influx.

Objective: To investigate the protocol of the construction of HERG gene mutations, an A561V mutation which was detected in a Chinese congenital long QT syndrome (LQTS) family had been constructed and expressed in vitro., Methods: The A561V cloning vector PGEM-HERG-A561V was constructed by quick site-directed mutagenesis PCR. The A561V expressive vector pcDNA3-HERG-A561V was constructed by restriction enzymes. pRK5-GFP was cotransfected with pcDNA3-HERG-A561V or wild type pcDNA3-HERG into HEK293 cells by Superfect transfection reagent. The protein was measured by immunofluorescence., Results: Direct sequence analyses revealed a C to T transition at position 1682. The A561V mutation was correctly combined to eukaryotic expressive vector pcDNA3 and expressed in HEK293 cells. The protein of mutation was expressed in cytoplasm and cellular membrane while the wild type gene was expressed only on cellular membrane., Conclusion: The protocol can be used successfully to construct and express HERG A561V mutation and it forms the basement of the further study on functions of mutation.

Objective: To screen for siRNAs that inhibit the expression of p42(MAPK) in HeLa cell line., Methods: Three p42(MAPK) siRNAs and one random siRNA were synthesized using Silencer siRNA Construction Kit, and labeled with Cy-3 for measurement of transfection effect. SiRNAs were transfected into HeLa cells by Lipofectamin 2000. The expression of p42(MAPK) was analyzed by Western blot. The biological effect of siRNAs on HeLa cell growth was monitored by MTT and flow cytometry., Results: Two siRNAs (siRNA-2 and siRNA-3) among three tested were identified to be able to downregulate the p42(MAPK) expression. A concurrent growth retardation of HeLa cell line was observed in comparison with the control., Conclusion: Inhibition of p42(MAPK) expression with siRNA technique can inhibit the proliferation of HeLa cells.

Objective: To study the effect of 20( R)-ginsenoside Rg3 on the expressions of angiogenesis factors proteins (VEGF,bFGF, MMP-2) in human lung adenocarcinoma cell line A549 and HUVEC304 cell., Method: The cell lines of A549 and HUVEC304 were cultured with 20(R)- Rg3. The gray scale and positive rate of VEGF, bFGF, MMP-2 were detected by immunohistochemistry. The differential expressions of genes were studied by DNA microarray., Result: The positive rate of VEGF protein in A549 cell decreased significantly as compared with the control group ( P = 0.03). The gray scales of VEGF, Flt, KDT proteins in both A549 cell lines and HUVEC 304 cell lines decreased ( P = 0.05). Gray scale of MMP-2 also decreased in A549 cell lines. The result of differential expressions of genes of A549 cell lines showed that 14 genes were down-regulated and 10 genes were up-regulated., Conclusion: The Chinese materia medica of 20( R)-Rg3 can inhibit the expression of angiogenesis factors proteins via several target genes in both tumour cell and vascular endothelial cell.

Objective: To observe the effects of NGF, estrogens and minoxidil on the growth of human hair follicle in vitro., Methods: In a model of human hair follicle in vitro, the follicle was separately treated with the NGF, estrogens and minoxidil. The growth of the hair follicle was measured in length with an eyepiece micrometer. The effects of the NGF, estrogens and minoxidil were evaluated by measuring the rates of incorporation of 3H-TdR of DNA synthesis., Results: The growth of the human hair follicle was showing significantly faster in the 100 ng/ml NGF and 125 micrograms/ml minoxidil groups, compared with the control (P < 0.05), but the growth was significantly inhibited in the 0.5 microgram/ml 17 beta-E2 group (P < 0.05). There was no difference shown for the growth of the hair follicle in the group mixed with 100 ng/ml NGF and 0.5 microgram/ml 17 beta-E2 (P > 0.05). The rates of incorporation of 3H-TdR in the groups were shown that the results just correlated with the results of the above-mentioned method., Conclusions: The 100 ng/ml NGF and 125 micrograms/ml minoxidil could increase the growth of human hair follicle while the 0.5 microgram/ml 17 beta-E2 could inhibit it. The 100 ng/ml NGF could neutralized the effect of the 0.5 microgram/ml 17 beta-E2.