Microindentation of Bi57In26Sn17 Lead-Free Alloy

There is great need to understand the mechanical properties of lead-free alloys—an alternative of lead-based alloys—to address the environmental problems associated with the use of lead-based materials in microelectronics. In this work, the microstructures of Bi57In26Sn17 lead-free alloy were examined using Optical Microscopy and Energy Dispersive X-ray Spectroscopy analysis. The micro-indentation technique was used to study the mechanical properties of Bi57In26Sn17 lead-free alloy. The experimental results of the hardness and contact modulus were presented and discussed. Local creep during the indentation was observed from the load-displacement curves. The Vickers hardness (HV) increases with the decrease of the indentation depth, suggesting that the alloy exhibits indentation size effect

Bis[2-(2-hydroxy-3-meth­oxy­phen­yl)benzimidazolium] tetrachlorido­cuprate(II) methanol disolvate

In the title compound, (C14H13N2O2)2[CuCl4]·2CH4O, the geometry of the CuC14 2− ions (Cu site symmetry 2) is inter­mediate between tetra­hedral and square-planar. The dihedral angle between the benzimidazole and benzene ring systems is 8.74(14)°. A network of N—H⋯O, N—H⋯Cl and O—H⋯Cl hydrogen bonds helps to consoldiate the structure. Aromatic π–π stacking inter­actions involving the benzimidazole ring system, with a centroid–centroid distance of 3.785 (3) Å, also occur

Research progress on the mechanism of anti-aging evaluation system for Lactic acid bacteria

Lactic acid bacteria (LAB) is the general name of a class of bacteria that can ferment sugars to produce acid and gas. Lactobacillus has rich species diversity and geographical distribution, including at least 18 genera and more than 200 species. It is widely used in food, animal husbandry, medicine, and other fields. In recent years, due to LAB’s excellent antioxidant and anti-aging properties, the research and development of corresponding functional products have become hot spots in various fields. Focusing on the excellent characteristics of antioxidation and anti-aging of LAB, this paper summarizes the evaluation system and analysis of effective active substances that can be used for screening anti-aging in order to provide the theoretical basis for screening functional LAB

Mechanism of METTL14-mediated ERα m6A regulation of endometrial cancer metastasis

Background and purpose: Aberrant N6-methyladenosine (m6A) modification caused by dysregulation of methyltransferase-like factor 14 (METTL14) plays an important role in the progression of various cancers, and it is unclear whether it is involved in the endometrial cancer (EC) progression. This study aimed to investigate the role of aberrant m6A modification caused by dysregulation of METTL14 in EC invasion and metastasis. Methods: Ninety-six EC patients who underwent curative surgery in Qinghai Provincial People’s Hospital from 2017 to 2021 were enrolled. RNA (70 pairs) or proteins (10 pairs) were isolated from frozen tissues for real-time fluorescence quantitative polymerase chain reaction (RTFQ-PCR) or immunoblot analysis to assess METTL14 expression in EC. The expression of METTL14 and its correlation with clinicopathological features of EC were assessed. The biological effects of METTL14 in EC were determined in vitro and in vivo. Methylated RNA immunoprecipitation sequencing (MeRIP-seq) combined with RNA sequencing (RNA-seq), and following m6A dot blot, MeRIP-RTFQ-PCR, RIP-RTFQ-PCR or dual luciferase reporter assays were employed to screen and validate the candidate targets of METTL14. Results: The mRNA expression and protein levels of METTL14 were significantly downregulated in EC compared with matched adjacent tissues. Compared with the METTL14 high expression group, the METTL14 low expression group had a significant increase in International Federation of Gynecology and Obstetrics (FIGO) stage, infiltration depth, lymphovascular invasion, lymph node metastasis and the number of cases of tumor metastasis (P<0.05). Functionally, METTL14 inhibited the proliferation and invasive capacity of EC cells in vitro and in vivo. Mechanistically, METTL14-mediated demethylation of m6A resulted in post-transcriptional repression of estrogen receptor alpha (ERα). Furthermore, compared with METTL14, ERα induced oncogenic behavior of tumors. Conclusion: METTL14 attenuates ERα expression in EC cells in a m6A-dependent manner, thereby inhibiting tumor metastasis and invasion

Characterization of Shiga toxin-producing Escherichia coli isolated from healthy pigs in China

BACKGROUND: Shiga toxin-producing Escherichia coli (STEC) is recognized as an important human diarrheal pathogen. Swine plays an important role as a carrier of this pathogen. In this study we determined the prevalence and characteristics of STEC from healthy swine collected between May 2011 and August 2012 from 3 cities/provinces in China. RESULTS: A total of 1003 samples, including 326 fecal, 351 small intestinal contents and 326 colon contents samples, was analyzed. Two hundred and fifty five samples were stx-positive by PCR and 93 STEC isolates were recovered from 62 stx-positive samples. Twelve O serogroups and 19 O:H serotypes including 6 serotypes (O100:H20/[H20], O143:H38/[H38], O87:H10, O172:H30/[H30], O159:H16, O9:H30/[H30]) rarely found in swine and ruminants were identified. All 93 STEC isolates harbored stx(2) only, all of which were stx(2e) subtype including 1 isolate being a new variant of stx(2e). 53.76%, 15.05% and 2.15% STEC isolates carried astA, hlyA and ehxA respectively. Four STEC isolates harbored the high-pathogenicity island. Of the 15 adherence-associated genes tested, 13 (eae, efa1, iha, lpfA(O113), lpfA(O157/OI-154), lpfA(O157/OI-141), toxB, saa, F4, F5, F6, F17 or F41) were all absent while 2 (paa and F18) were present in 7 and 4 STEC isolates respectively. The majority of the isolates were resistant to tetracycline (79.57%), nalidixic acid (78.49%), trimethoprim-sulfamethoxazole (73.12%) and kanamycin (55.91%). The STEC isolates were divided into 63 pulsed-field gel electrophoresis patterns and 21 sequence types (STs). Isolates of the same STs generally showed the same or similar drug resistance patterns. A higher proportion of STEC isolates from Chongqing showed multidrug resistance with one ST (ST3628) resistant to 14 antimicrobials. CONCLUSIONS: Our results indicate that swine is a significant reservoir of STEC strains in China. Based on comparison by serotypes and sequence types with human strains and presence of virulence genes, the swine STEC may have a low potential to cause human disease

Impact of early enteral nutrition on ventilator associated pneumonia in intubated severe trauma patients: A propensity score-matched study

BackgroundEarly enteral nutrition (EN) is recommended for critically ill patients. However, the impact of early EN on intubated severe trauma patients remains unclear.MethodsSeverely traumatized adult patients who received invasive mechanical ventilation (MV) for more than 48 h during intensive care unit (ICU) stay at our institution between 2017 and 2022 were retrospectively included. Early EN was defined as EN initiation ≤48 h from ICU admission and late EN >48 h. Propensity score matching (PSM) analysis was used to compare outcomes between the groups. The primary endpoint was the incidence of ventilator-associated pneumonia (VAP). Multivariable logistic regression analysis was performed to identify independent predictors of delayed EN.ResultsFor final analysis, 337 intubated severe trauma patients were available, including 204 (60.5%) in the early EN group and 133 (39.5%) in the late EN group. After PSM, early EN patients had a lower incidence of VAP (12.9 vs. 25.8%, p = 0.026) and a shorter length of hospital stay (21 vs. 24 days, p = 0.015) compared to late EN patients. There was no demonstrable difference in mortality between the two groups. Abdominal trauma, massive blood transfusion, and serum albumin were identified as independent risk factors for delayed EN.ConclusionEarly EN decreased the VAP rate and reduced the length of hospital stay in invasively ventilated patients with severe trauma. Abdominal injury, massive blood transfusion and low albumin were associated with delayed EN

Acetylation Targets the M2 Isoform of Pyruvate Kinase for Degradation through Chaperone-Mediated Autophagy and Promotes Tumor Growth

Most tumor cells take up more glucose than normal cells but metabolize glucose via glycolysis even in the presence of normal levels of oxygen, a phenomenon known as the Warburg effect. Tumor cells commonly express the embryonic M2 isoform of pyruvate kinase (PKM2) that may contribute to the metabolism shift from oxidative phosphorylation to aerobic glycolysis and tumorigenesis. Here we show that PKM2 is acetylated on lysine 305 and that this acetylation is stimulated by high glucose concentration. PKM2 K305 acetylation decreases PKM2 enzyme activity and promotes its lysosomal-dependent degradation via chaperone-mediated autophagy (CMA). Acetylation increases PKM2 interaction with HSC70, a chaperone for CMA, and association with lysosomes. Ectopic expression of an acetylation mimetic K305Q mutant accumulates glycolytic intermediates and promotes cell proliferation and tumor growth. These results reveal an acetylation regulation of pyruvate kinase and the link between lysine acetylation and CMA

A Novel Escherichia coli O157:H7 Clone Causing a Major Hemolytic Uremic Syndrome Outbreak in China

An Escherichia coli O157:H7 outbreak in China in 1999 caused 177 deaths due to hemolytic uremic syndrome. Sixteen outbreak associated isolates were found to belong to a new clone, sequence type 96 (ST96), based on multilocus sequence typing of 15 housekeeping genes. Whole genome sequencing of an outbreak isolate, Xuzhou21, showed that the isolate is phylogenetically closely related to the Japan 1996 outbreak isolate Sakai, both of which share the most recent common ancestor with the US outbreak isolate EDL933. The levels of IL-6 and IL-8 of peripheral blood mononuclear cells induced by Xuzhou21 and Sakai were significantly higher than that induced by EDL933. Xuzhou21 also induced a significantly higher level of IL-8 than Sakai while both induced similar levels of IL-6. The expression level of Shiga toxin 2 in Xuzhou21 induced by mitomycin C was 68.6 times of that under non-inducing conditions, twice of that induced in Sakai (32.7 times) and 15 times higher than that induced in EDL933 (4.5 times). Our study shows that ST96 is a novel clone and provided significant new insights into the evolution of virulence of E. coli O157:H7