超厚壁无缝钢管纵向缺陷超声波检测探讨

介绍了超厚壁无缝钢管的接触法和水浸法检测方法,分析了超厚壁无缝钢管的声束覆盖区域。分析认为:当钢管的厚径比大于0.26,无论纯横波法还是变型横波法均无法探测钢管内壁缺陷,所以采用“小角度折射纵波+折射纯横波”检测超厚壁钢管纵向缺陷;采用双探头的探伤,实际上对钢管截面的内圆(r~0.5R)部分实施的是纵波检测,而对外圆(0.5R~R)部分实施的是横波+纵波检测。

Noncoding RNAs in cancer and cancer stem cells

In recent years, it has become increasingly apparent that noncoding RNAs(ncRNA) are of crucial importance for human cancer. The functional relevance of ncRNAs is particularly evident for microRNAs(miRNAs) and long noncoding RNAs(lncRNAs). miRNAs are endogenously expressed small RNA sequences that act as post-transcriptional regulators of gene expression and have been extensively studied for their roles in cancers, whereas lncRNAs are emerging as important players in the cancer paradigm in recent years. These noncoding genes are often aberrantly expressed in a variety of human cancers. However, the biological functions of most ncRNAs remain largely unknown. Recently, evidence has begun to accumulate describing how ncRNAs are dysregulated in cancer and cancer stem cells, a subset of cancer cells harboring self-renewal and differentiation capacities. These studies provide insight into the functional roles that ncRNAs play in tumor initiation, progression, and resistance to therapies, and they suggest ncRNAs as attractive therapeutic targets and potentially useful diagnostic tools.

水合肼还原制备纳米铜粉的工艺优化

通过液相还原法水合肼还原制备纳米铜粉,考察了反应温度、抗氧化剂添加量、PVP添加量、反应时间、体系pH值、铜盐浓度、还原剂的浓度等因素对铜颗粒的粒径与形貌的影响。通过对上述影响因素优化,从而得到粒径小、分散性好、空气中抗氧化的纳米铜粉。

Lipid Production by <i>Rhodotorula glutinis</i>from Pulp and Paper Wastewater for Biodiesel Production

This study investigated the potential of oleaginous yeast Rhodotorula glutinis utilizing pulp and paper wastewater effluents as cultivation media for the sustainable production of microbial lipids as biodiesel feedstock. R. glutinis is oleaginous yeast, which has the ability to produce significant quantities of intercellular lipids in the form of triacylglycerols. Yeast lipids are a promising potential feedstock for biodiesel production due to similar fatty acid composition to plant oils. The effect of various carbon sources on biomass production, lipid accumulation, substrate utilization, and fatty acid composition using R. glutinis in the pulp and paper wastewater media was studied. The pulp and paper wastewater was supplemented with glucose, xylose, and glycerol as carbon sources under nitrogen-limited conditions. The maximum lipid productions of 1.3 - 2.9 g&bull;L–1, which corresponded to the intracellular lipid contents of 8% - 15% cell dry weight (CDW), were obtained under various carbon substrates. A kinetic study of the batch fermentation was performed in a 3 L aerobic batch fermenter to describe the cell growth, lipid accumulation, and substrate utilization process, and the kinetic parameter was estimated. The fatty acid profile of oleaginous yeast was rich in palmitic, oleic, and linoleic acids and comparable to vegetable oils. Thus, the results of this study indicated that pulp and paper wastewater could be used to produce lipids as biodiesel feedstock.

NaCl-KCl-Na2WO4熔融体系的电导率研究

针对NaCl-KCl-Na2WO4熔融体系,采用交流电极法对熔盐体系的电导率进行研究。结果表明:在1173~1203K之间,NaCl-KCl-Na2WO4熔盐体系的电导率随着Na2WO4含量先逐渐减小再逐渐增大,在10%Na2WO4时电导率最小。在1218~1233K之间,NaCl-KCl-Na2WO4熔盐体系的电导率随着钨酸钠含量的增加而逐渐增大。NaCl-KCl-Na2WO4(0%~15%)熔盐体系的电导率与温度之间呈线性关系。NaCl-KCl-10%Na2WO4熔盐体系受到温度的影响最大。

Utilization of Soluble Starch by Oleaginous Red Yeast Rhodotorula glutinis

Starch containing wastewaters from the food and feed industry have been identified as potential cheap carbon sources for the production of microbial lipids. Due to its high potential lipid content the oleaginous yeast Rhodotorula glutinis is often used for fermentations in this field. Moreover it is investigated in the context of microbial carotenoid production, which also requires a cheap source of carbon. Thus, the ability of R. glutinis (ATCC 15125TM) to degrade and utilize soluble starch for the production of lipids has been assessed in this study. While glucose and fructose were readily consumed from the medium, starch was only slightly reduced in one treatment. The yield of fatty acid methyl esters (FAME) was graduated corresponding to the initial sugar contents, with the highest FAME yield (1.5 g·L-1) at the highest initial sugar content. In the treatment that contained starch as single carbon source, no FAME production was realized. Accordingly, if starchy wastewaters should be used for microbial cultivation with R. glutinis, an enzymatic or chemical pretreatment for starch hydrolysis should be applied, to increase the availability of this carbon source.

Stimuli-responsive photoluminescent copper(Ⅰ) halides for scintillation, anticounterfeiting, and light-emitting diode applications

Highly sensitive stimuli-responsive luminescent materials are crucial for appli-cations in optical sensing,security,and anticounterfeiting.Here,we report two zero-dimensional(0D)copper(I)halides,(TEP)_(2)Cu_(2)Br_(4),(TEP)_(2)Cu_(4)Br_(6),and 1D(TEP)_(3)Ag_(6)Br_(9),which are comprised of isolated[Cu_(2)Br_(4)]^(2-),[Cu_(4)Br_(6)]^(2-),and[Ag_(6)Br_(9)]3-polyanions,respectively,separated by TEP^(+)(tetraethylphosphonium[TEP])cations.(TEP)_(2)Cu_(2)Br_(4) and(TEP)_(2)Cu_(4)Br_(6) demonstrate greenish-white and orange-red emissions,respectively,with near unity photoluminescence quantum yields,while(TEP)_(3)Ag_(6)Br_(9) is a poor light emitter.Optical spectroscopy mea-surements and density-functional theory calculations reveal that photoemissions of these compounds originate from self-trapped excitons due to the excited-state distor-tions in the copper(I)halide units.Crystals of Cu(I)halides are radioluminescence active at room temperature under both X-andγ-rays exposure.The light yields up to 15,800 ph/MeV under 662 keVγ-rays of ^(137)Cs suggesting their potential for scintillation applications.Remarkably,(TEP)_(2)Cu_(2)Br_(4) and(TEP)_(2)Cu_(4)Br_(6) are inter-convertible through chemical stimuli or reverse crystallization.In addition,both compounds demonstrate luminescence on-off switching upon thermal stimuli.The sensitivity of(TEP)_(2)Cu_(2)Br_(4) and(TEP)_(2)Cu_(4)Br_(6) to the chemical and thermal stimuli coupled with their ultrabright emission allows their consideration for applications such as solid-state lighting,sensing,information storage,and anticounterfeiting.

A review of selective laser melting of aluminum alloys: Processing,microstructure, property and developing trends

Selective laser melting(SLM) is an attractive rapid prototyping technology for the fabrication of metallic components with complex structure and high performance. Aluminum alloy, one of the most pervasive structural materials, is well known for high specific strength and good corrosion resistance. But the poor laser formability of aluminum alloy restricts its application. There are problems such as limited processable materials, immature process conditions and metallurgical defects on SLM processing aluminum alloys. Some efforts have been made to solve the above problems. This paper discusses the current research status both related to the scientific understanding and technology applications. The paper begins with a brief introduction of basic concepts of aluminum alloys and technology characterization of laser selective melting. In addition, solidification theory of SLM process and formation mechanism of metallurgical defects are discussed. Then, the current research status of microstructure, properties and heat treatment of SLM processing aluminum alloys is systematically reviewed respectively. Lastly, a future outlook is given at the end of this review paper.

Mantle-derived Xenoliths and the Token of a Modern Back-Arc Geotherm Beneath Eastern China

Xenoliths of garnet and spinel-garnet 1herzolite from Mingxi, Eastern China have been studied in terms of comprehensive methods of mineralogy, petrology, fabrics, mierostructures and infrared spectrum. The temperature and pressure equilibration of the xenolith have been calculated using the TEMPEST program with the two-pyroxene geothermometer of Bertrand and Mercier (1985) combined with the geobarometer of Nickel and Green (1985). The temperature and pressure of xenoliths range from^1300 K at 1. 9 GPa (60 km) to ~1500 K at 2. 6 GPa (80 km). The geotherm inferred from xenolith is excellently consistent with the measured surface heat flow (70 mW/m2) in Mingxi. A character of geothermal curve and conductive type suggest that these xenoliths are from the lithosphere, not from the asthenosphere. The geotherm and mierostructures and preferred orientations of minerals in the xenolith are consistent with tecon-ic thinning of the lithosphere in the present-day extensional back-arc environment.

Reciprocal effects of alpha-synuclein aggregation and lysosomal homeostasis in synucleinopathy models

Background Lysosomal dysfunction has been implicated in a number of neurodegenerative diseases such as Parkinson’s disease(PD).Various molecular,clinical and genetic studies have highlighted a central role of lysosomal pathways and proteins in the pathogenesis of PD.Within PD pathology the synaptic protein alpha-synuclein(αSyn)converts from a soluble monomer to oligomeric structures and insoluble amyloid fibrils.The aim of this study was to unravel the effect ofαSyn aggregates on lysosomal turnover,particularly focusing on lysosomal homeostasis and cathepsins.Since these enzymes have been shown to be directly involved in the lysosomal degradation ofαSyn,impairment of their enzymatic capacity has extensive consequences.Methods We used patient-derived induced pluripotent stem cells and a transgenic mouse model of PD to examine the effect of intracellularαSyn conformers on cell homeostasis and lysosomal function in dopaminergic(DA)neurons by biochemical analyses.Results We found impaired lysosomal trafficking of cathepsins in patient-derived DA neurons and mouse models withαSyn aggregation,resulting in reduced proteolytic activity of cathepsins in the lysosome.Using a farnesyltransferase inhibitor,which boosts hydrolase transport via activation of the SNARE protein ykt6,we enhanced the maturation and proteolytic activity of cathepsins and thereby decreasedαSyn protein levels.Conclusions Our findings demonstrate a strong interplay betweenαSyn aggregation pathways and function of lysosomal cathepsins.It appears thatαSyn directly interferes with the enzymatic function of cathepsins,which might lead to a vicious cycle of impairedαSyn degradation.

DNA damage and metabolic mechanisms of cancer drug resistance

Cancer drug resistance is one of the main barriers to overcome to ensure durable treatment responses.While many pivotal advances have been made in first combination therapies,then targeted therapies,and now broadening out to immunomodulatory drugs or metabolic targeting compounds,drug resistance is still ultimately universally fatal.In this brief review,we will discuss different strategies that have been used to fight drug resistance from synthetic lethality to tumor microenvironment modulation,focusing on the DNA damage response and tumor metabolism both within tumor cells and their surrounding microenvironment.In this way,with a better understanding of both targetable mutations in combination with the metabolism,smarter drugs may be designed to combat cancer drug resistance.

Tumor microenvironment signaling and therapeutics in cancer progression

Tumor development and metastasis are facilitated by the complex interactions between cancer cells and theirmicroenvironment,which comprises stromal cells and extracellular matrix(ECM)components,among other factors.Stromal cells can adopt new phenotypes to promote tumor cell invasion.Adeep understanding of the signaling pathways involved in cell-to-cell and cell-to-ECM interactions is needed to design effective intervention strategies that might interrupt these interactions.In this review,we describe the tumor microenvironment(TME)components and associated therapeutics.We discuss the clinical advances in the prevalent and newly discovered signaling pathways in the TME,the immune checkpoints and immunosuppressive chemokines,and currently used inhibitors targeting these pathways.These include both intrinsic and non-autonomous tumor cell signaling pathways in the TME:protein kinase C(PKC)signaling,Notch,and transforming growth factor(TGF-β)signaling,Endoplasmic Reticulum(ER)stress response,lactate signaling,Metabolic reprogramming,cyclic GMP–AMP synthase(cGAS)–stimulator of interferon genes(STING)and Siglec signaling pathways.We also discuss the recent advances in Programmed Cell Death Protein 1(PD-1),Cytotoxic T-Lymphocyte Associated Protein 4(CTLA4),T-cell immunoglobulin mucin-3(TIM-3)and Lymphocyte Activating Gene 3(LAG3)immune checkpoint inhibitors along with the C-C chemokine receptor 4(CCR4)-C-C class chemokines 22(CCL22)/and 17(CCL17),C-C chemokine receptor type 2(CCR2)-chemokine(C-Cmotif)ligand 2(CCL2),C-C chemokine receptor type 5(CCR5)-chemokine(C-C motif)ligand 3(CCL3)chemokine signaling axis in the TME.In addition,this review provides a holistic understanding of the TME as we discuss the three-dimensional and microfluidic models of the TME,which are believed to recapitulate the original characteristics of the patient tumor and hence may be used as a platform to study new mechanisms and screen for various anti-cancer therapies.We further discuss the systemic influences of gut microbiota in TME reprogramming and treatment response.Overall,this review provides a comprehensive analysis of the diverse and most critical signaling pathways in the TME,highlighting the associated newest and critical preclinical and clinical studies along with their underlying biology.We highlight the importance of the most recent technologies of microfluidics and lab-on-chip models for TME research and also present an overview of extrinsic factors,such as the inhabitant human microbiome,which have the potential to modulate TME biology and drug responses.

Reentrant equilibrium disordering in nanoparticle-polymer mixtures

A large body of experimental work has established that athermal colloid/polymer mixtures undergo a sequence of transitions from a disordered fluid state to a colloidal crystal to a second disordered phase with increasing polymer concentration.These transitions are driven by polymer-mediated interparticle attraction,which is a function of both the polymer density and size.It has been posited that the disordered state at high polymer density is a consequence of strong interparticle attractions that kinetically inhibit the formation of the colloidal crystal,i.e.,the formation of a non-equilibrium gel phase interferes with crystallization.Here we use molecular dynamics simulations and density functional theory on polymers and nanoparticles(NPs)of comparable size and show that the crystal-disordered phase coexistence at high polymer density for sufficiently long chains corresponds to an equilibrium thermodynamic phase transition.While the crystal is,indeed,stabilized at intermediate polymer density by polymer-induced intercolloid attractions,it is destabilized at higher densities because long chains lose significant configurational entropy when they are forced to occupy all of the crystal voids.Our results are in quantitative agreement with existing experimental data and show that,at least in the nanoparticle limit of sufficiently small colloidal particles,the crystal phase only has a modest range of thermodynamic stability.

隐源性卒中的心电监测策略：2015年卒中诊断和监测专题组的报告

卒中是一个重要的全球性公共卫生问题。2010年全世界总共发生3300万例卒中，其中1690万为首发卒中。卒中是仅次于心脏病的第二大全球人口死亡原因，占全部死亡的10％以上。卒中是一类异质性疾病，其病因可以是血管破裂（出血性）或血管闭塞（缺血性）。缺血性卒中约占全部卒中的85％，可根据发病机制进行分类。