Intrinsic Correlation between Hardness and Elasticity in Polycrystalline Materials and Bulk Metallic Glasses

Though extensively studied, hardness, defined as the resistance of a material to deformation, still remains a challenging issue for a formal theoretical description due to its inherent mechanical complexity. The widely applied Teter's empirical correlation between hardness and shear modulus has been considered to be not always valid for a large variety of materials. Here, inspired by the classical work on Pugh's modulus ratio, we develop a theoretical model which establishes a robust correlation between hardness and elasticity for a wide class of materials, including bulk metallic glasses, with results in very good agreement with experiment. The simplified form of our model also provides an unambiguous theoretical evidence for Teter's empirical correlation.Comment: 10 pages, 4 figures and 3 table

An experimental study on reshaping C110 deformed casing with spinning casing swage

Casing deformation affects the implementation of stimulation and development measures of oilfields directly; however, the reshaping force and torque usually are determined by experience when the deformed casing is repaired with the spinning reshaping technology; if the repairing force or torque is too large, it will result in the damage of casing and cement sheath as well as sticking accident. So, the collapse experiments were performed on the YAW-200 pressure testing machine by using one production casing which is often used in the oilfield and then the reshaping test of deformed casing (C110) was performed in turn by using two spinning casing swages of which the diameter is 126 mm and 129 mm respectively. The continuous rotator and thrust bearing were used to provide the torque and reshaping force respectively in the repairing process. The reshaping force and torque required to reshape the deformed casing, the deformation law and the springback value of deformed casing were obtained. Test results show that the diameter differential between the two spinning casing swages is reasonable. Furthermore, in order to ensure the safety and reliability of the implementation of post-production technologies, the mechanical properties of deformed casing before and after reshaping were tested. It was found that all the mechanical parameters of the deformed casing after reshaping reduced, which resulted in the decrease of the strength of the reshaped casing. These research achievements would provide important experimental data in optimizing the structure and construction parameters of spinning casing swages

Klebsiella grimontii, a New Species Acquired Carbapenem Resistance

Klebsiella grimontii is a newly identified species closely related to Klebsiella oxytoca, but carbapenem resistance was not identified in the species before. We found a carbapenem-resistant K. oxytoca-like clinical strain, WCHKG020121. The strain was subjected to whole genome sequencing using Illumina HiSeq X10. The precise species identification was established based on average nucleotide identity (ANI) and in silico DNA–DNA hybridization (isDDH) between strain WCHKG020121 and type strains of Klebsiella species. Antimicrobial resistance genes were identified from the genome sequence. The sequence of the blaKPC-2-carrying plasmid was completed using PCR and Sanger sequencing. Conjugation experiments were performed to obtain the plasmid carrying blaKPC-2. All K. grimontii genomes were retrieved from GenBank and were analyzed for antimicrobial resistance genes. Strain WCHKG020121 was resistant to imipenem and meropenem (MIC for both, 32 μg/ml) but was susceptible to colistin (1 μg/ml). Strain WCHKG020121 was initially identified as K. oxytoca using Vitek II but it actually belongs to K. grimontii as it had a 98.81% ANI and 83.4% isDDH value with K. grimontii type strain. Strain WCHKG020121 had blaKPC-2; by contrast, none of other K. grimontii genomes carry any known carbapenemase genes. blaKPC-2 was carried by a 95,734-bp plasmid, designated pKPC2_020121, which contained two different FII(Y) replicons. pKPC2_020121 was closest (93% coverage, 99% identity) to blaKPC-2-carrying plasmids from Enterobacter hormaechei recovered in 2014 at the same hospital. pKPC2_020121 was not self-transmissible, which could be explained by the absence of a conjugation essential gene, traY. In conclusion, we reported the first K. grimontii strain that produced the KPC carbapenemase. Carbapenem resistant K. grimontii may represent a new threat

CRC Therapy Identifies Indian Hedgehog Signaling in Mouse Endometrial Epithelial Cells and Inhibition of Ihh-KLF9 as a Novel Strategy for Treating IUA

Intrauterine adhesion (IUA) causes menstrual disturbance and infertility. There is no effective treatment available for moderate to severe IUA cases. Stem cell-based therapy has been investigated for treating IUA but is limited in clinical applications due to issues including the precise induction of differentiation, tumorigenesis, and unclear molecular mechanisms. In our recent study, we isolated and expanded the long-term cultures of conditional reprogrammed (CR) mouse endometrial epithelial cells. Treating IUA mice with these CR cells (CRCs) restored the morphology and structure of the endometrium and significantly improved the pregnancy rate. In this study, our data with high-throughput sequencing, CRISPR knockout Ihh−/−CRCs, and transplantation identified for the first time that the Indian hedgehog (Ihh) gene plays a critical role in the regulation of endometrial epithelial cell proliferation. We also found that aberrant activated Ihh-krüppel-like factor 9 (KLF9) signaling contributes to the inhibition of normal progesterone receptor (PR) function in IUA mice. Thus, we hypothesized that inhibition of the Ihh-KLF9 pathway may be a novel strategy to treat IUA. Our data demonstrated that treatment with the hedgehog signaling inhibitor Vismodegib restored the morphology, structure, and microenvironment of the endometrium, and greatly improved the pregnancy rate in IUA mice. This study suggests a promising application of hedgehog inhibitors as a targeted drug in the IUA clinic

The chicken pan-genome reveals gene content variation and a promoter region deletion in IGF2BP1 affecting body size

Domestication and breeding have reshaped the genomic architecture of chicken, but the retention and loss of genomic elements during these evolutionary processes remain unclear. We present the first chicken pan-genome constructed using 664 individuals, which identified an additional ∼66.5 Mb sequences that are absent from the reference genome (GRCg6a). The constructed pan-genome encoded 20,491 predicated protein-coding genes, of which higher expression level are observed in conserved genes relative to dispensable genes. Presence/absence variation (PAV) analyses demonstrated that gene PAV in chicken was shaped by selection, genetic drift, and hybridization. PAV-based GWAS identified numerous candidate mutations related to growth, carcass composition, meat quality, or physiological traits. Among them, a deletion in the promoter region of IGF2BP1 affecting chicken body size is reported, which is supported by functional studies and extra samples. This is the first time to report the causal variant of chicken body size QTL located at chromosome 27 which was repeatedly reported. Therefore, the chicken pan-genome is a useful resource for biological discovery and breeding. It improves our understanding of chicken genome diversity and provides materials to unveil the evolution history of chicken domestication.Funding provided by: National Natural Science Foundation of ChinaCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100001809Award Number: 31902144Funding provided by: Program for Innovation Research Team of the Ministry of Education*Crossref Funder Registry ID: Award Number: IRT16R23Funding provided by: The Scientific Studio of Zhongyuan Scholars*Crossref Funder Registry ID: Award Number: 30601985Funding provided by: Program for Innovation Research Team of the Ministry of EducationCrossref Funder Registry ID: Award Number: IRT16R23Funding provided by: The Scientific Studio of Zhongyuan ScholarsCrossref Funder Registry ID: Award Number: 3060198