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An experimental investigation was conducted on the single-tooth pulsating bending fatigue of 38SiMnMo alloy steel at a frequency range of 140–150 Hz. Using both up–down test method and S–N curve extension method, statistical data in terms of curves and endurance limits were analysed. The testing and analytical results indicated that the ‘platform’ of fatigue curves exists and the S–N curve cannot be extended to the cyclic basic number Nb in order to obtain the endurance limit. Furthermore, on the basis of the life distribution optimization, the three-parameter Weibull distribution was used for statistical data analysis. The statistical analysis showed that the bending endurance limit of 38SiMnMo alloy steel gears estimated at 99 per cent reliability and 95 per cent confidence was 284 MPa, which was located at the slightly low part of the mean line in the chart range illustrated in the standards ISO6336 and GB3480. The results demonstrated that the method described in this article was valuable. [ABSTRACT FROM AUTHOR]

The Pb(Zr1-xTix)O3 multilayered films consisting of Pb(Zr0.8Ti0.2)O3 and Pb(Zr0.2Ti0.8)O3 layers were deposited on LaNiO3(110)/Pt/Ti/SiO2/Si substrates by rf magnetron sputtering. All films comprise five periodicities, the layer thicknesses of rhombohedral (dR) and tetragonal (dT) phases in one periodicity are varied. The LaNiO3 buffer layer leads to the (101)/(110) orientation of the films. The electrical properties of the films were investigated as a function of dR/dT. The films with dR/dT=1:2 possess enhanced dielectric and ferroelectric properties. The mechanism of the enhanced electrical properties was discussed, and it was found that the strain is also an important factor to affect electrical properties. [ABSTRACT FROM AUTHOR]

Objectives: To identify the Y-chromosomal genetic types for the soldier's remains from Huaihai Campaign, and to offer a clue for search of their paternal relatives., Methods: DNA of the remains were extracted by the ancient DNA extraction method. Yfiler kit was used for the multiplex amplification of 17 Y-STR loci. The haplogroups of the samples were speculated. Detailed genotyping of the selected Y-SNP was performed based on the latest Y-chromosome phylogenetic tree. Haplotype-sharing analysis was done based on the data of Y-SNP and Y-STR, the closest modern individual information to the genetic relationship of remains was gained., Results: A total of 8 Y-STR haplotypes were observed on 17 Y-STR loci of 8 male individuals. Furthermore, 6 Y-SNP haplogroups were identified, which were O2a1-M95+, O1a1-P203+, O3*-M122+/M234-, D1-M15+, C3*-ST and R1a1-M17+., Conclusions: Identification of Y-chromosomal genetic types for the soldier's remains from Huaihai Campaign shows a reference value on inferring the geographical origins of old materials., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Editorial Department of Journal of Forensic Medicine)

Objective: To investigate the effect of zinc ion on the expression of osteoblastic proteins., Methods: Mice osteoblasts MC3T3-E1 cells were subcultured. Inflammatory environment model was established by tumor necrosis factor α(TNF-α)at a concentration of 10 mg/L. According to different concentration of Zn(2+), the cells were divided into TNF-α group, control group, group A(TNF-α+10(-4) mol/L Zn(2+)), group B(TNF-α+10(-5) mol/L Zn(2+)), group C(TNF-α+10(-6) mol/L Zn(2+)). After 24, 48, and 72 h of culture, cell counting kit-8(CCK-8)assay was used to analyze the proliferation of the cells. ALP activity was examined. Bone morphogenetic protein-2(BMP-2), Runt-related transcription factor 2(RUNX2), Osterix and receptor activator of NF-κB ligand(RANKL)protein levels were determined by Western blotting after 72 h of culture., Results: The cells grew by adherence after 24 h. After 72 h, the cells grew dense, and the cells showed long spindle shape or irregular shape. The proliferation of osteoblasts in TNF-α group, group B and group C became lower than that in the control group(P<0.05), and was not significantly different between group A and the control group(P >0.05). ALP activity examination demonstrated that the groups cultured for 72 h revealed the highest ALP activity and the most prominent differentation compared with 24 h and 48 h groups. ALP activity was significantly decreased in TNF-α group, group B and group C compared with control group(P<0.05), but was not significantly different between group A and control group(P>0.05). The protein levels of BMP-2, RUNX2 and Osterix were significantly decreased in TNF-α group, group B and group C compared with control group(P<0.05), while showed no significant difference between group A and the control group. Protein level of RANKL was significantly increased in TNF-α group, grope B and group C compared with control group(P<0.05), while showed no significant difference between group A and control group., Conclusions: The concentration of 10(-4) mol/L Zn(2+) can significantly increase the expression of osteoblastic proteins such as ALP, BMP-2, RUNX2, Osterix and decrease the expression of RANKL in mice osteoblasts in TNF-α inflammatory environment.

The NS3 and NC protein genes encoded by RNA3 of RStV, the NCP and NSvc4 protein genes encoded by RNA4 were subcloned into the E. coli expression vector pGEX3X to express four groups of fusion protein under IPTG induction. These fusion proteins were used to immunize rabbits to raise antisera. The antisera against the E. coli-expressed proteins were available for probing the presence of the viral gene products in both rice plant and insect hosts. The expected gene products can be probed only in diseased rice plant with NCP antiserum and the corresponding products detected in both plant and RStV particle preparation with NC antiserum. The viral gene products probed by NS3 and NSvc4 antisera were different from the expected ones in size.

In a cell line (NB4) derived from a patient with acute promyelocytic leukemia, all-trans-retinoic acid (ATRA) and interferon (IFN) induce the expression of a novel gene we call RIG-G (for retinoic acid-induced gene G). This gene codes for a 58-kDa protein containing 490 amino acids with several potential sites for post-translational modification. In untreated NB4 cells, the expression of RIG-G is undetectable. ATRA treatment induces the transcriptional expression of RIG-G relatively late (12-24 hr) in a protein synthesis-dependent manner, whereas IFN-alpha induces its expression early (30 min to 3 hr). Database search has revealed a high-level homology between RIG-G and several IFN-stimulated genes in human (ISG54K, ISG56K, and IFN-inducible and retinoic acid-inducible 58K gene) and some other species, defining a well conserved gene family. The gene is composed of two exons and has been mapped by fluorescence in situ hybridization to chromosome 10q24, where two other human IFN-stimulated gene members are localized. A synergistic induction of RIG-G expression in NB4 cells by combined treatment with ATRA and IFNs suggests that a collaboration exists between their respective signaling pathways.

We have previously found that 5,6-EET (epoxyeicosatrienoic acid)(50 nM) significantly dilates the vascular bed(42%) of the isolated, constantly perfused rabbit lung, which has been constricted with U46619(5-8 pM). We studied the role of EDRF-NO and prostaglandins in the 5,6-EET-induced vascular relaxation. Dilation to 5,6-EET was evident only when the pulmonary vascular tone was increased. L-NNA (N omega-nitro-L-arginine, 10(-4) M), an inhibitor of NO synthase(NOS); U46619(5-10 pM), a thromboxane mimetic; and L-NNA + INDO(indomethacin, 10(-5) M), a cyclooxygenase inhibitor, all increased the pressure of pulmonary artery(PPa) from baseline, to a peak range of 28-38mmHg(32.75 [symbol: see text] 2.2), whereas INDO alone increased Ppa only by 10mmHg. L-NNA + INDO,L-NNA alone, and INDO + U46619 attenuated the 5,6-EET relaxing effect by 100%, 88% and 64.5%, respectively. In the presence of L-NNA and 5,6-EET, SNAP(S-nitroso-N-acetyl-D,L-penicillamine, 10(-6) M), a NO donor, reduced Ppa by 75%. We conclude that the mechanism of vasodilation to 5,6-EET in the rabbit pulmonary circulation is via both EDRF-NO and PG pathways and that the vasodilation is largely EDRF-NO dependent.

The long civilization of China traces its origin to the development of agriculture. Early records and archaeological findings demonstrate the success of plant and animal breeding in contributing to human livelihood and the national economy. Teaching and research in modern genetics began in China in the 1920s with individuals who received advanced training in the West. Over the following 30 years, notable contributions to genetics, both basic and applied, were made by Chinese scientists in universities and research institutions. Unfortunately, these activities were brought to a virtual standstill first by the official advocacy of Lysenkoism, followed by ten years of Cultural Revolution. Schools were closed and scientific research was interrupted. Not until 1978 did the universities begin to enroll new students and scientific research, including genetics, again receive endorsement. Since then, Chinese scientists have resumed contacts with colleagues in other countries and publication of their research findings in national and international journals. The material summarized in this article covers a long time span and a broad spectrum of scientific subjects and events. Representative examples of Chinese contributions to various areas of genetics are cited to depict the history, current status, and prospects for the development of genetics in China. After many ups and downs and despite limitations in material resources, the study of genetics in China seems to be on a sound footing, with a relatively complete system in place for training workers in this discipline.

A simple method for the identification of mutational sites in human mitochondrial DNA (mtDNA) was described. It was based on the human Cambridge sequence as a relative standard sequence and a single base pair substitution in mtDNA as a unique mutational form. The partial mutational sites can be determined using this method which was characterized by combining the restriction mapping with the analysis for the table of human mtDNA potential mutational sites with rapidity and simplicity. In the meanwhile, six mtDNA mutational sites found in Chinese population were identified by means of this method.

Human mitochondrial DNA (mtDNA) restriction endonuclease fragment patterns were analyzed using placenta DNA isolated from 273 individuals representing four different nationalities, the Han, the Uygur, the Kazakh and the Hui populations. Thirty-eight fragment patterns (morphs) were observed with the enzyme ApaI, BamHI, EcoRI, HindIII, HinfI, HhaI, HapII, KpnI, Mbol, PstI, PvuII, SacI, ScaL and XhoI. Fourteen new morphs, including some only existing in individual racial and national populations were observed, which indicates that there is a significant difference in the distribution of mtDNA morphs among various national and racial populations. By comparison with the mtDNA sequences in primate species, some mtDNA ancestral morphs were found to be retained in Oriental population today. This result provided indirect evidence that Asia may be one of the human original sources. Genetic distances among four national populations computed and employed in construction of an average linkage tree suggested that the Uygur and the Kazakh populations combined to form a branch at first, then the Han and the Hui came together to form another one, and at last, these two branches converged into a stem. Again, it was found that the internal variation within the Uygur and the Kazakh populations was greater than that within the Han and the Hui populations. These results showed a relationship among the four different national populations in China based on the molecular level.

Using techniques of polyacrylamide slab electrophoresis and agarose electrophoresis, we have detected genetic variation at 6 loci which coding for enzymes in 4 local samples from natural population of Drosophila virilis. We found 50% of the loci detected are polymorphic, depending on the criterion of polymorphism used. An individual is heterozygotes on the average at 27.13% of its loci. The amount of genetic variation fluctuates widely from locus to locus. At Est-alpha, Est-beta, Amy, most of the individuals are heterozygotes. At the other extreme , Mdh, aGpdh, Acph, few individuals are heterozygotes. For Mdh, we have measured the thermostability at 53 degrees C. No more genetic variation was found. We have measured the amount of genetic differentiation between different local populations. The result showed that there is no relationship between geographical distance and genetic distance. The results are discussed in the light of the continuing controversy over selection and natural theories of genetic variation. We think that both selection and stochastic processes must operate simultaneously in most systems.