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We elucidate here the underlying reasons for the yield point elongation (YPE) phenomenon in medium-Mn steel. The cold-rolled Fe-0.2C-11Mn-2Al steel was subjected to controlled annealing temperature and soaking time such that YPE of different lengths was obtained. It was observed that the ultra-fine grained or globular microstructure is not the critical factor responsible for YPE. YPE is a consequence of close competition between the work hardening (via martensitic transformation) and softening (by stress relaxation and transfer) induced by the TRIP effect. The ferrite grains with γ fiber have the potential to have high dislocation storage ability, with consequent increase in dislocation density and work hardening exponent, leading to decrease of YPE.

Background: Zymomonas mobilis is a natural ethanologen being developed and deployed as an industrial biofuel producer. To date, eight Z. mobilis strains have been completely sequenced and found to contain 2-8 native plasmids. However, systematic verification of predicted Z. mobilis plasmid genes and their contribution to cell fitness has not been hitherto addressed. Moreover, the precise number and identities of plasmids in Z. mobilis model strain ZM4 have been unclear. The lack of functional information about plasmid genes in ZM4 impedes ongoing studies for this model biofuel-producing strain. Results: In this study, we determined the complete chromosome and plasmid sequences of ZM4 and its engineered xylose-utilizing derivatives 2032 and 8b. Compared to previously published and revised ZM4 chromosome sequences, the ZM4 chromosome sequence reported here contains 65 nucleotide sequence variations as well as a 2400-bp insertion. Four plasmids were identified in all three strains, with 150 plasmid genes predicted in strain ZM4 and 2032, and 153 plasmid genes predicted in strain 8b due to the insertion of heterologous DNA for expanded substrate utilization. Plasmid genes were then annotated using Blast2GO, InterProScan, and systems biology data analyses, and most genes were found to have apparent orthologs in other organisms or identifiable conserved domains. To verify plasmid gene prediction, RNA-Seq was used to map transcripts and also compare relative gene expression under various growth conditions, including anaerobic and aerobic conditions, or growth in different concentrations of biomass hydrolysates. Overall, plasmid genes were more responsive to varying hydrolysate concentrations than to oxygen availability. Additionally, our results indicated that although all plasmids were present in low copy number (about 1-2 per cell), the copy number of some plasmids varied under specific growth conditions or due to heterologous gene insertion. Conclusions: The complete genome of ZM4 and two xylose-utilizing derivatives is reported in this study, with an emphasis on identifying and characterizing plasmid genes. Plasmid gene annotation, validation, expression levels at growth conditions of interest, and contribution to host fitness are reported for the first time. © 2018 The Author(s).

Previous studies have demonstrated that the CXCL12 G801A polymorphism is closely correlated with tumor susceptibility. In addition, the CXCL12/CXCR4 pathway is closely related to proliferation, metastasis, and invasion of glioma. However, the genetic effects of the CXCL12 G801A polymorphism on glioma risk in Chinese populations remain unknown. In this study, we investigated the potential associations between the CXCL12 G801A polymorphism with glioma susceptibility and its clinicopathological characteristics. Frequencies of CXCL12 G801A polymorphic variants between glioma patients (N = 750) and healthy controls (N = 750) were assessed using restriction length fragment polymorphism analysis. The association among the CXCL12 G801A polymorphism, glioma grade (WHO classification), and histological type was also evaluated. Our results showed that patients with glioma had significantly higher frequency of the CXCL12-3' A/A genotypes (P = 0.039) as compared with healthy controls. When stratified by the glioma histology, high-grade glioma patients had significantly higher frequency of the CXCL12-3' A/A genotypes (P = 0.019) as compared with low-grade glioma patients. When stratified by the WHO grade, significantly higher frequency of the CXCL12-3' A/A genotype was observed in stage IV glioma patients (P = 0.037). We conclude that the CXCL12 G801A polymorphism is a risk factor that increases susceptibility to gliomas in a subset of the general Han Chinese population.

There are significant differences on the biological characteristics of bone marrow mesenchymal stem cells (BMMSCs), immunological response, and antigen-presenting functions between patients with psoriasis and normal subjects, but there are no significant differences in aborted fetuses. We examined the differences in BMMSCs between aborted fetuses and patients with psoriasis in this study. Bone marrow from normal subjects, aborted fetuses, and patients with psoriasis were obtained using a MidiMACS machine. Density gradient centrifugation method was used to isolate the bone marrow mononuclear cells of patients with psoriasis and aborted fetus and the cells were cultivated. Bone marrow CD34(+) cells from normal subjects were isolated. MTT colorimetric detection was used to test the proliferation activity of bone marrow CD34(+) cells. The purity of bone marrow CD34(+) cells and BMMSCs was determined by flow cytometry. The BMMSC culture supernatant fluid of patients with psoriasis and aborted fetuses showed no statistically significant difference with bone marrow CD34(+) cell proliferation in normal subjects (P0.05).