Measurement of Creep Stress Exponent of TC17 Titanium Alloy by Nanoindentation Method at Room Temperature.

The creep stress exponent is commonly employed to characterize the deformation mechanism during the steady-state creep stage, serving as an indicator of creep behavior. The creep phenomenon of high melting point metallic materials is not obvious at room temperature. However, the nanoindentation method proves suitable for investigating the creep properties of metallic materials under such conditions. Consequently, this paper places emphasis on measuring the creep stress exponent of TC17 titanium alloy at room temperature using the load preservation stage of the nanoindentation method with a constant loading rate. In order to investigate the effects of loading rate and maximum load on the experimental results, different loading rates were applied to the diamond Berkovich indenter to reach different maximum loads. The indenter was held under the maximum load for a duration of 360 s, and the relationship between the indentation strain rate and indentation stress during the holding process was used to obtain the creep stress exponent of the material at room temperature. The findings indicate that within the loading rate range of 1.25 to 15 mN/s and maximum load range of 50 to 300 mN, the influence on the experimental results is insignificant. Ultimately, the distribution range of the creep stress exponent for TC17 titanium alloy at room temperature was measured to be 8.524-8.687.

Forensic entomology application in China: Four case reports.

We present four cases that use entomological data to estimate postmortem interval (PMI). In the first case, the body was found in an outdoor environment at 26 °C and was at the fresh stage. However, the PMImin estimated using maggots collected from the corpse was more than 68 h. This was certainly an incorrect estimation because the degree of the body decomposition was light, and it may have been caused by flies invading the corpse before death occurred. In the second case, a corpse of an adult male was found in a semi-closed room, and the body was highly decomposed and mummified. In this case, we used Dermestes maculatus DeGeer (Coleoptera: Dermestidae) to successfully estimate the PMI. The third case involved a female body discovered in her room after she committed suicide by consuming excessive clozapine and alcohol. The PMImin estimated through entomological data did not match the time of death that the other evidence indicated. Thus, we speculated that clozapine and alcohol may have influenced the development of fly larvae. The fourth case occurred in the winter. The murderer killed the victim and burned and dumped the corpse. However, the burned body still attracted necrophagous insects and we successfully calculated the PMImin by using insect evidence.

[Analysis of linkage disequilibrium and linkage for 12 short tandem repeat loci on chromosome X].

OBJECTIVE: To analyze linkage disequilibrium of 12 short tandem repeat loci on chromosome X (X-STR) among an ethnic Han population from Guilin, Guangxi, and to study the genetic linkage and haplotype distributions of such loci in 2 linkage groups. METHODS: 12 X-STR loci including DXS8378, DXS10159, DXS10162, DXS10164, DXS981, DXS6789, DXS7424, DXS101, DXS7133, GATA165B12, GATA31E08 and DXS7423 were genotyped using an AGCU X12 STR PCR Amplification kit. A total of 119 pedigrees were analyzed for linkage and linkage disequilibrium. RESULTS: Two mutations were found at DXS7424, and 1 mutation was found at DXS10164. A total of 93 haplotypes of DXS10159-DXS10162-DXS10164 were constructed for 261 unrelated males and females, in addition with 167 haplotypes of DXS6789-DXS7424-DXS101-DXS7133. The values of recombination fraction between DXS10159 and DXS10162, DXS10162 and DXS10164, DXS6789 and DXS7424, and DXS7424 and DXS101 were 0.0269, 0.0236, 0.0505 and 0.0438, respectively. CONCLUSION: Linkage disequilibrium of X-STR does not only depend on physical and genetic distances. There was incomplete linkage relationship between loci on DXS10159-DXS1016-DXS10164 and DXS6789-DXS7424-DXS101 linkage groups.

[Association of ABCG2 gene C421A polymorphism and susceptibility of primary gout in Han Chinese males].

OBJECTIVE: To assess the association between a C421A single nucleotide polymorphism (SNP) in exon 5 of ATP-binding cassette, sub-family G (WHITE), member 2 (ABCG2) gene and susceptibility of primary gout in Han Chinese males. METHODS: For 200 male patients with primary gout and 235 controls, the genotype of C421A locus was analyzed by PCR and direct sequencing. Blood glucose, uric acid, total cholesterol, triglycerides, creatinine and urea nitrogen was measured by an automatic biochemical analyzer. RESULTS: Compared with the controls, there was a higher frequency for AA genotype and A allele of the rs2231142 SNP in gout patients (22.5% vs. 8.5% by genotype; 44.9% vs. 32.3% by allele). The association with gout reached significance (chi-square =15.91, P< 0.001, crude OR=3.02, 95% CI:1.36-4.90 and OR (adjusted by age)=1.80, 95% CI: 1.32-2.45 by dominant mode; chi-square=6.82, P=0.009, OR=1.67, 95% CI: 1.54-2.27 by recessive mode). Blood glucose, uric acid, triglycerides, creatinine and urea nitrogen levels in gout patients were significantly higher than those of controls (P< 0.001). CONCLUSION: The C421A SNP, in particular AA phenotype, may be associated with susceptibility of primary gout in Han Chinese males.