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Exosomes have been documented to function in human diseases, yet their transfer of microRNA (miRNA) in preeclampsia (PE) has seldom been reported. This study intends to discuss the role of miR-133b derived from exosomes in human umbilical cord mesenchymal stem cells (hUC-MSCs) in trophoblast cell development in PE. Placentas from PE patients and normal pregnant women were collected. The hUC-MSCs and their exosomes were obtained and identified. Trophoblast cell HPT-8 and HTR8-S/Vneo were obtained and co-cultured with hUC-MSCs-derived exosomes that had been transfected with different miR-133b plasmids. MiR-133b and glucocorticoid-regulated kinase 1 (SGK1) expression in placental tissues and HPT-8 and HTR8-S/Vneo cells was determined. HTR8-S/Vneo and HPT-8 cell proliferation, cell cycle distribution, apoptosis rate, migration and invasion were detected. MiR-133b was down-regulated and SGK1 was up-regulated in placental tissues of PE patients. MiR-133b expression was inversely related to SGK1 expression in HTR8-S/Vneo and HPT-8 cells co-cultured with hUC-MSC-derived exosomes. Exosomes promoted HTR8-S/Vneo and HPT-8 cell proliferation, migration and invasion abilities, cell cycle entry and inhibited apoptosis. Elevated exosome-derived miR-133b from hUC-MSCs boosted HTR8-S/Vneo and HPT-8 cell proliferation, cell cycle progression, migration and invasion and limited cell apoptosis. MiR-133b targeted SGK1. Collectively, we demonstrate that miR-133b is down-regulated and SGK1 is up-regulated in PE, and miR-133b derived from exosomes in hUM-MSCs facilitates trophoblast cell proliferation, migration and invasion in PE via constraining SGK1. [ABSTRACT FROM AUTHOR]

An experimental investigation on the joining process of 6061 aluminum alloy and carbon fiber reinforced thermoplastics composite (CFRTP) has been carried out with swing laser. The application of the swing laser is beneficial to obtain a larger bonding area. The effects of scanning speed are investigated on the interface formation and fracture load of the hybrid joint. In addition, the formation mechanism of the interface and the fracture mode of the hybrid joint are further elucidated. The results indicate that maximum failure load is obtained with appropriate process parameters (scanning speed: 20 mm/s, laser power: 2000 W), whereas the interface morphology under this process parameter demonstrates that the structurally sound connection between CFRTP and aluminum alloy is realized by the mechanical interlocking effect. At a higher scanning speed, the gaps in the interface caused by insufficient heat input per unit length result in a lower failure load, while at a lower scanning speed, the bubbles and gaps at the interface are observed as a result of resin decomposition and trapped pyrolysis gases in the interface, ultimately reducing the failure load of the joint. Moreover, the fracture mode of the hybrid joint is a mixed failure. [ABSTRACT FROM AUTHOR]

Immunomodulation by mesenchymal stem cells (MSCs) is potentially important for maintaining peripheral tolerance. Preeclampsia may be due to maternal immune rejection of the genetically foreign fetus. This study aimed to investigate the biological function of human umbilical cord–derived mesenchymal stem cells (HU-MSCs) for the treatment of angiotensin receptor agonistic autoantibody (AT1-AA)-induced hypertension during pregnancy. HU-MSCs were isolated, cultured, and labeled in vitro. AT1-AA and HU-MSCs were administered to pregnant rats. Green fluorescent protein (GFP)–positive HU-MSCs infused in vivo were identified by immunofluorescence. Systolic blood pressure (SBP) was evaluated. The effects of HU-MSCs on fetal weight, kidney burden, and spiral artery remodeling, as well as on the expression of tumor necrosis factor α (TNF-α), interleukin 10 (IL-10), and heme oxygenase 1 (HO-1), were investigated. The SBP levels in the HU-MSC-treated pregnant hypertension rats decreased by gestational day 19. The reduction in fetal weight was largely ameliorated after HU-MSC treatment. Lesion burden in the kidney was attenuated and spiral artery remodeling was improved in HU-MSC-treated pregnant hypertension rats. However, green fluorescent protein (GFP)–labeled cells were sparingly observed in the kidney and placenta. Intravenous infusion of HU-MSCs into AT1-AA-induced rats significantly downregulated serum TNF-α levels and upregulated IL-10 levels, concomitant with increased placenta and mesometrial triangle (MT) HO-1 expression. Taken together, intravenous infusion of HU-MSCs ameliorates AT1-AA-induced pregnancy hypertension, intrauterine growth retardation, kidney impairment, and spiral artery remodeling impairment. Moreover, the potential benefits of HU-MSCs may be attributable to both an interference with the pathogenic immune response and a paracrine cytoprotective action. [ABSTRACT FROM PUBLISHER]

We reported a green and simple Cu-catalyzed method for the efficient synthesis of 2-chloro-7-cyclopentyl-N,N-dimethyl-7H-pyrrolo[2,3-d]pyrimidine-6-carboxamide as the key intermediate in the synthetic approaches to pyrrolo[2,3-d]pyrimidine derivatives from 5-bromo-2,4-dichloropyrimidine through two routes in four steps and five steps, respectively. This method provided green and economical approaches toward numerous pyrrolo[2,3-d]pyrimidine derivatives. [ABSTRACT FROM PUBLISHER]

The present investigation aims to contrast the effect of the commonly used thermal frequency on welding process suitability, weld profile, weld macrostructure, and weld hardness on AA6061 aluminum alloy double pulsed gas metal arc welding. Material manufacturing processes and welding parameters with thermal frequencies of 2, 3, and 4 Hz are described in detail. Three defect-free welds were successfully formed at these thermal frequencies. The results indicate the following: (1) thermal frequency has no effect on welding process suitability when the welding parameters are self-matching; and (2) at increased thermal frequency, weld ripple distance reduces, maximum penetration depth decreases, grain size of the fusion zone decreases, and fusion zone hardness increases. [ABSTRACT FROM PUBLISHER]

In the paper, basing on the structure of Nekrasov matrices, the authors first obtain several practical criteria for judgingH-matrices, then provide some criteria for identifying that a given matrix is not anH-matrix. The effectiveness of the proposed results is illustrated by numerical examples. [ABSTRACT FROM PUBLISHER]

A new welding method, which uses a Gaussian current waveform with a smooth curve and concentrated energy input, was applied for welding of aluminum alloys of various thickness. Current peak modulation and base modulation models are proposed in the article. Five welding experiments were carried out using ER4043 1.2 mm aluminum wire, the results showing that the welding process was found to be stable, and that current and voltage waveforms were regular with no broken arcs or short circuits. Moreover, the arc voice sound was soft with low splatter. Weld seam surfaces were bright with regular scaly stripes and proper weld height and penetration. [ABSTRACT FROM AUTHOR]