Porcine uterus contains a population of mesenchymal stem cells

The uterus has a remarkable ability of cycling remodeling throughout the reproductive life of the female. Recent findings in the human and mouse indicate that adult stem/progenitor cells may play a prominent role in the maintenance of uterine endometrial and myometrial homeostasis. We aimed to characterize the prospective stem/progenitor cells in the porcine uterus and establish a new model for uterine stem cell research. In this study, we demonstrated that cells isolated from porcine uterus have capacity for in vitro differentiation into adipogenic and osteogenic lineages and express the mesenchymal stem cell (MSC) markers CD29, CD44, CD144, CD105, and CD140b as revealed by RT-PCR. Moreover, we showed that some cells isolated from the porcine uterus when cultured at low density produce large clones with an efficiency of 0.035%. Simultaneously, they were negative for hematopoietic stem cell markers such as CD34 and CD45. Low expression of nestin, which is specific for neural stem cells and various progenitor cells, was also detected. We conclude that the porcine uterus contains a small population of undifferentiated cells with MSC-like properties similar to human and mouse uteri.     

Potential of Telomerase in Age-Related Macular Degeneration—Involvement of Senescence,DNA Damage Response and Autophagy and a Key Role of PGC-1α

Age-related macular degeneration (AMD), the main cause of vision loss in the elderly, is associated with oxidation in the retina cells promoting telomere attrition. Activation of telomerase was reported to improve macular functions in AMD patients. The catalytic subunit of human telomerase (hTERT) may directly interact with proteins important for senescence, DNA damage response, and autophagy, which are impaired in AMD. hTERT interaction with mTORC1 (mTOR (mechanistic target of rapamycin) complex 1) and PINK1 (PTEN-induced kinase 1) activates macroautophagy and mitophagy, respectively, and removes cellular debris accumulated over AMD progression. Ectopic expression of telomerase in retinal pigment epithelium (RPE) cells lengthened telomeres, reduced senescence, and extended their lifespan. These effects provide evidence for the potential of telomerase in AMD therapy. Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) may be involved in AMD pathogenesis through decreasing oxidative stress and senescence, regulation of vascular endothelial growth factor (VEGF), and improving autophagy. PGC-1α and TERT form an inhibitory positive feedback loop. In conclusion, telomerase activation and its ectopic expression in RPE cells, as well as controlled clinical trials on the effects of telomerase activation in AMD patients, are justified and should be assisted by PGC-1α modulators to increase the therapeutic potential of telomerase in AMD.     

Experimental investigation of the effect of fuel nozzle geometry on the stability of a swirling non-premixed methane flame

An experimental investigation on the stability of a swirling non-premixed methane flame is reported in this paper. Methane gas is supplied through a central nozzle, and combustion (co-flow) air is supplied through an annulus surrounding the nozzle. Two main parameters were varied independently, which are the nozzle geometry and swirl strength; however the exit velocity of the central (fuel nozzle) jet and co-airflow were also varied to provide a wide range of test conditions. Two nozzles were tested: a contracted circular (referred to hereafter as CCN) and a rectangular (referred to hereafter as RN), which have similar equivalent diameter, D_e (defined as the diameter of a round slot having the same exit area as the nozzle geometry). The contracted circular nozzle has a diameter of 4.82 mm, and the rectangular nozzle has a diameter of 4.71 with an aspect ratio of 2:1. The swirl strength of the co-flow was varied by changing the vanes’ angle. The main results obtained from this study show that the rectangular nozzle exhibits higher entrainment and jet spreading rates compared with its CCN counterpart. In addition, the results revealed that increasing the swirl strength creates a flow recirculation zone which is larger with the RN compared with that of the corresponding CCN. These flow features associated with the RN lead to an enhanced mixing which consequently promotes better flame stability compared with its CCN counterpart.     

Supercritical water gasification of biomass for hydrogen production

Hydrogen from waste biomass is considered to be a clean gaseous fuel and efficient for heat and power generation due to its high energy content. Supercritical water gasification is found promising in hydrogen production by avoiding biomass drying and allowing maximum conversion. Waste biomass contains cellulose, hemicellulose and lignin; hence it is essential to understand their degradation mechanisms to engineer hydrogen production in high-pressure systems. Process conditions higher than 374 °C and 22.1 MPa are required for biomass conversion to gases. Reaction temperature, pressure, feed concentration, residence time and catalyst have prominent roles in gasification. This review focuses on the degradation routes of biomass model compounds such as cellulose and lignin at near and supercritical conditions. Some homogenous and heterogeneous catalysts leading to water–gas shift, methanation and other sub-reactions during supercritical water gasification are highlighted. The parametric impacts along with some reactor configurations for maximum hydrogen production and technical challenges encountered during hydrothermal gasification processes are also discussed.     

Kynurenine Pathway of Tryptophan Metabolism in Migraine and Functional Gastrointestinal Disorders

Migraine, the leading cause of disability in the population aged below 50, is associated with functional gastrointestinal (GI) disorders (FGIDs) such as functional nausea, cyclic vomiting syndrome, and irritable bowel syndrome (IBS). Conversely, changes in intestinal GI transit may cause diarrhea or constipation and are a component of the autonomic symptoms associated with pre- and post-dorsal phases of migraine attack. These mutual relationships provoke a question on a common trigger in migraine and FGIDs. The kynurenine (l-kyn) pathway (KP) is the major route for l-tryptophan (l-Trp) metabolism and transforms l-Trp into several neuroactive compounds. Changes in KP were reported in both migraine and FGIDs. Migraine was largely untreatable, but several drugs approved lately by the FDA, including monoclonal antibodies for calcitonin gene-related peptide (CGRP) and its receptor, create a hope for a breakthrough in migraine treatment. Derivatives of l-kyn were efficient in pain relief with a mechanism including CGRP inhibition. KP products are important ligands to the aryl hydrocarbon receptor (AhR), whose activation is implicated in the pathogenesis of GI and migraine. Toll-like receptors (TLRs) may play a role in migraine and IBS pathogeneses, and KP metabolites detected downstream of TLR activation may be an IBS marker. The TLR4 signaling was observed in initiating and maintaining migraine-like behavior through myeloid differentiation primary response gene 88 (MyD88) in the mouse. The aim of this review is to justify the view that KP modulation may provide common triggers for migraine and FGIDs with the involvement of TLR, AhR, and MyD88 activation.     

Surface morphology of steel and titanium induced by ion beam bombardment – Comprehensive analysis

It is well known that ion bombardment of solid surface modifies its physical and chemical properties, among others, surface morphology. In this paper we try to concentrate on four aspects of ion beam induced surface morphology, i.e.: (a) surface topography, (b) surface roughness, (c) rate of profile shape variability, and (d) surface morphology arrangement. Surface topographies (in micro- and nanometre range) were observed by means of scanning electron and near-field microscopes. High quality profilograph and atomic force microscope were utilised to measure surface roughness parameters. To do that, surface profiles must be well known. To detect any profile shape alteration during ion beam bombardment we used fractal analysis, and especially fractal dimension D that can give information about rate of profile shape variability. Surface morphology arrangement, i.e. a question whether it is random or determined, was studied with the use of frequency plots resulting from harmonic analysis of profiles.We studied surface topographies, selected roughness parameters, fractal dimensions and frequency plots relating to stainless steel and polycrystalline 99.5% titanium bombarded with perpendicular low energy (800 eV) broad argon ion beam as well as neutralized narrow argon or krypton ion beam (up to 6 keV).     

电弧炉粉尘等温还原的动力学研究

为使还原条件与实际电弧炉生产相接近,在等温条件下对电弧炉粉尘球团的还原过程动力学进行了研究。电弧炉粉尘与还原剂碳和粘接剂石灰均匀混合后制粒,经干燥后将球闭置于恒定温度的加热炉中,利用电子称定时对球团重量进行检测。金属还原率的计算中,考虑了球团的失重、铅和锌在高温下挥发。经研究,电弧炉粉尘的还原分为二个阶段,还原初期由化学反应控制而还原后期由扩散控制,并建立了每一阶段的还原动力学方程,确定了有关的动力学参数表观活化能和频率因子。     

电弧炉粉尘球团直接还原的热传导模型

对电弧炉炼钢粉尘加上还原剂碳混合制粒成的球团还原过程的热传导行为进行了研究,根据实验推导了球团导热模型的结构参数,并试图建立热传导模型。