Transcriptome and carotenoid profiling of different varieties of Coffea arabica provides insights into fruit color formation

The processability and ultimate quality of coffee(Coffea arabica)are determined by the composition of the matured fruits.The basis of genetic variation in coffee fruit quality could be explained by studying color formation during fruit maturation.Transcriptome profiling was conducted on matured fruits of four C.arabica varieties(orange colored fruits(ORF);purple colored fruits(PF);red colored fruits(RF)and yellow colored fruits(YF))to identify key color-regulating genes,biosynthesis pathways and transcription factors implicated in fruit color formation.A total of 39,938 genes were identified in the transcriptomes of the four C.arabica varieties.In all,2745,781 and 1224 differentially expressed genes(DEGs)were detected in YF_vs_PF,YF_vs_RF and YF_vs_ORF,respectively,with 1732 DEGs conserved among the three pairwise groups.Functional annotation of the DEGs led to the detection of 28 and 82 key genes involved in the biosynthesis of carotenoids and anthocyanins,respectively.Key transcription factors bHLH,MYB,NAC,MADS,and WRKY implicated in fruit color regulation were detected.The high expression levels of gene-LOC113688784(PSY),gene-LOC113730013(b-CHY),gene-LOC113728842(CCD7),gene-LOC113689681(NCED)and gene-LOC113729473(ABA2)in YF may have accounted for the yellow coloration.The differential expression of several anthocyanin and carotenoid-specific genes in the fruits substantially account for the purple(PF),red(RF),and orange(ORF)colorations.This study provides important insights into fruit color formation and variations in C.arabica and will help to develop coffee varieties with specific color and quality traits.

Magnesium nickel hydride monocrystalline nanoparticles for reversible hydrogen storage

Although Mg-based hydrides are extensively considered as a prospective material for solid-state hydrogen storage and clean energy carriers,their high operating temperature and slow kinetics are the main challenges for practical application.Here,a Mg-Ni based hydride,Mg_(2)NiH_(4) nanoparticles(~100 nm),with dual modification strategies of nanosizing and alloying is successfully prepared via a gas-solid preparation process.It is demonstrated that Mg_(2)NiH_(4) nanoparticles form a unique chain-like structure by oriented stacking and exhibit impressive hydrogen storage performance:it starts to release H2 at~170℃ and completes below 230℃ with a saturated capacity of 3.32 wt%and desorbs 3.14 wt% H_(2) within 1800 s at 200℃.The systematic characterizations of Mg_(2)NiH_(4) nanoparticles at different states reveal the dehydrogenation behavior and demonstrate the excellent structural and hydrogen storage stabilities during the de/hydrogenated process.This research is believed to provide new insights for optimizing the kinetic performance of metal hydrides and novel perspectives for designing highly active and stable hydrogen storage alloys.

利用SNP芯片信息评估新疆近交牛基因组纯合度

新疆近交牛是经45年近亲繁育形成的近交群体,但由于繁育记录缺失,其原始亲本品种未知。为了明确新疆近交牛的遗传背景,并探索利用基因组信息评价牛群近交水平的可行性,本研究利用该群体及荷斯坦牛、新疆褐牛和哈萨克牛等16个国内外牛品种的SNP芯片数据,应用主成分分析和Admixture方法对塔城地区新疆近交牛的群体结构进行分析;通过进一步计算新疆近交牛、荷斯坦牛、新疆褐牛和哈萨克牛的群体遗传学参数以及基因组近交指标评估各群体近交程度;结合新疆近交牛的体型分类和基因组近交指标信息,探讨了个体近交程度与体型表现的关系;最后,基于对新疆近交牛和哈萨克牛高频长纯合片段区域的筛选,鉴定了新疆近交牛基因组特征区域。研究结果显示,新疆近交牛的遗传背景与哈萨克牛基本一致,近交牛基因组纯合程度明显高于其他群体,且基因纯合率越高的近交牛其体型越小,在一定程度上呈现了近交衰退对体型的影响。本研究还鉴定到与新疆近交牛基因组特征区域相关的6个基本生物学通路以及与重要经济性状相关的32个数量基因座(quantitative trait loci,QTL)。本研究结果为新疆近交牛这一特殊遗传资源的育种规划及未来该群体的开发利用提供了科学依据。

糖尿病合并视网膜脱离术后高眼压的处理及危险因素探讨

目的:观察糖尿病合并孔源性视网膜脱离患者行玻璃体切割术后短期内眼压的波动情况并探讨可能的危险因素及有效的治疗方法。方法:连续收集100例糖尿病合并高度近视及孔源性视网膜脱离的患者并分为两组:试验组和对照组,试验组患者术后使用妥布霉素地塞米松滴眼液。分别监测术眼玻璃体切割术术前及术后的眼压情况,神经纤维层厚度(RNFL)和视盘参数,同时记录对侧眼术前的情况。实验数据采用Graphpad 7.0进行分析。结果:所有的糖尿病患者中有42眼在玻璃体切割术后1wk内出现眼压升高,其中试验组31眼,而对照组11眼。术后5d-1wk及1mo时两组间差异有显著统计学意义。随后,39眼经过治疗后眼压下降,3眼接受了青光眼滤过手术。与眼压升高前的视盘各参数相比,眼压升高后,平均及下方RNFL厚度变薄,盘沿面积变小,同时视杯容积和垂直杯盘比增加。眼压升高患者对侧眼的RNFL厚度相比于从未出现高压眼的患者明显变薄。结论:玻璃体切割术术后连续使用激素类药物是糖尿病合并视网膜脱离患者术后眼压升高的危险因素,并且可疑青光眼患者使用激素后眼压更易升高。

TRAF6基因沉默对人视网膜母细胞瘤细胞增殖、凋亡和侵袭的影响

目的:探讨体外沉默肿瘤坏死因子受体相关因子6(TRAF6)基因对人视网膜母细胞瘤Y79细胞增殖、凋亡和侵袭的影响。方法:靶向TRAF6基因的小干扰RNA(TRAF6 siRNA)转染Y79细胞,采用qRT-PCR和Western blot法检测转染效果,MTT比色法及细胞克隆实验测定沉默TRAF6对Y79细胞增殖的影响,流式细胞术检测细胞凋亡及细胞周期,Transwell小室检测细胞迁移和侵袭能力。结果:Y79细胞经TRAF6沉默后,TRAF6 mRNA和蛋白表达水平与对照组相比均明显降低,细胞存活率、克隆形成率均明显低于对照组细胞,细胞凋亡率明显高于对照组,同时细胞周期发生明显变化,G0/G1期细胞数目增多,S和G2/M期细胞数目减少,且侵袭细胞数目、迁移细胞数目相比对照组明显减少。结论:沉默TRAF6后能显著抑制视网膜母细胞瘤Y79细胞的生长,促进肿瘤细胞的凋亡,同时抑制其侵袭和迁移能力,TRAF6可能是视网膜母细胞瘤治疗的新靶点。

刺五加根皮乙醇提取物和短梗五加根皮乙醇提取物对小鼠的镇静催眠作用及其机制

目的:对比刺五加根皮乙醇提取物(SENR)和短梗五加根皮乙醇提取物(SESR)的镇静催眠作用及其作用机制,探讨短梗五加根皮替代刺五加根皮的可行性。方法:根据测定指标的不同,选择雄性昆明小鼠360只,每120只随机分为空白对照组,地西泮组(DZP,3 mg·kg^-1,灌胃给药),不同剂量(4、8、16、32和64 mg·kg^-1)SENR组和不同剂量(4、8、16、32和64 mg·kg^-1)SESR组,每组10只,连续给药5 d,记录各组小鼠自主活动次数;利用亚催眠剂量(28 mg·kg^-1)戊巴比妥钠诱导睡眠实验记录小鼠睡眠发生率,利用催眠剂量(48 mg·kg^-1)戊巴比妥钠诱导睡眠实验记录小鼠睡眠潜伏期和睡眠时间,筛选出SENR和SESR的亚催眠剂量和催眠剂量。根据模型药[5-羟色氨酸(5-HTP)和氟马西尼(FLU)]的不同,雄性ICR小鼠180只,每60只随机分为空白对照组、模型对照组、SENR组、SESR组、SENR+模型药组和SESR+模型药组,每组10只,连续给药5 d,采用戊巴比妥钠诱导睡眠实验记录各组小鼠的睡眠发生率、睡眠潜伏期和睡眠时间,采用ELISA法测定小鼠脑组织中5-羟色胺(5-HT)和γ-氨基丁酸(GABA)水平。结果:与空白对照组比较,DZP组、不同剂量(8、16、32和64 mg·kg^-1)SENR组和不同剂量(8、16、32和64 mg·kg^-1)SESR组小鼠自主活动次数明显减少(P<0.05或P<0.01),睡眠发生率增加,睡眠潜伏期缩短且睡眠时间延长(P<0.05或P<0.01);依据实验结果,选择SENR和SESR的亚催眠剂量为4 mg·kg^-1,催眠剂量为32 mg·kg^-1。5-HTP模型实验,与空白对照组、SENR(4 mg·kg^-1)组和SESR(4 mg·kg^-1)组比较,SENR+5-HTP组和SESR+5-HTP组小鼠睡眠发生率增加,睡眠潜伏期缩短(P<0.01),睡眠时间延长(P<0.01),脑组织中5-HT水平升高(P<0.01);FLU模型实验,与空白对照组比较,SENR(32 mg·kg^-1)组和SESR(32 mg·kg^-1)组小鼠睡眠潜伏期缩短(P<0.01),睡眠时间延长(P<0.01);与SENR(32 mg·kg^-1)组和SESR(32 mg·kg^-1)组比较,SENR+FLU组和SESR+FLU组小鼠睡眠潜伏期延长(P<0.01),睡眠时间缩短(P<0.01),脑组织中GABA水平降低(P<0.05)。结论:SENR和SESR均具有镇静催眠作用,其作用机制与上调脑组织中5-HT和GABA水平有关;在镇静催眠方面,短梗五加根皮可作为刺五加根皮的替代品。

OCTA评价无糖尿病视网膜病变患者黄斑区微循环特征的Meta分析

目的:采用Meta分析的方法,对光学相干断层扫描血管成像技术(OCTA)测量无糖尿病视网膜病变(NDR)的患者黄斑区的血流密度(VD)及浅层中心凹无血管区(FAZ)面积进行系统评价,探讨糖尿病早期视网膜的微循环特征。方法:在PubMed、Embase、Web of Science、Cochrane Library数据库中全面检索发表于2011-01-01/2021-01-05之间关于OCTA分析NDR患者黄斑区不同区域血流密度的研究。比较NDR组与正常对照组(同期年龄、性别与NDR组患者相匹配的健康人群)在浅层旁中心凹血流密度(spafVD)、浅层中心凹周围血流密度(spefVD)、深层旁中心凹血流密度(dpafVD)、深层中心凹周围血流密度(dpefVD)、浅层FAZ面积、最佳矫正视力(BCVA)。结果:研究纳入文献13篇,共1227眼(正常对照组558眼,NDR组669眼)。Meta分析结果显示:与正常对照组相比,NDR组spafVD(MD=-1.90,95%CI:-2.43~-1.37,P<0.00001)、spefVD(MD=-1.29,95%CI:-2.14~-0.44,P=0.003)、dpafVD(MD=-2.18,95%CI:-2.69~-1.67,P<0.00001)、dpefVD(MD=-2.37,95%CI:-3.27~-1.46,P<0.00001)显著降低,其中dpefVD降低更明显;浅层FAZ面积(MD=0.04,95%CI:0.03~0.06,P<0.00001)增大;两组BCVA比较无差异(MD=0.00,95%CI:-0.01~0.02,P=0.44)。结论:黄斑区深层中心凹周围区毛细血管损伤是糖尿病患者视网膜微循环障碍的最早期表现,也是糖尿病视网膜病变临床随访的关键指标。

降眼压药物对青光眼患者眼表影响的研究进展

青光眼是一种累及视网膜神经节细胞的慢性视神经病变,以视乳头萎缩、视野缺损及视力下降为共同特征的疾病。由于青光眼是一种慢性疾病,长期滴用局部降眼压药物往往会合并眼表疾病,从而降低药物依从性,最终影响治疗效果。目前局部降眼压药物主要有前列腺素类衍生物、β-肾上腺素能受体阻滞剂、α-肾上腺素能受体激动剂、局部碳酸酐酶抑制剂、拟胆碱能类药物。本文就以上5种降眼压药物对青光眼患者眼表影响和相关机制做一综述,并为青光眼患者的眼表保护提供预防性措施。

Unfolding analysis of LaBr3:Ce gamma spectrum with a detector response matrix constructing algorithm based on energy resolution calibration

With respect to the gamma spectrum, the energy resolution improves with increase in energy. The counts of full energy peak change with energy, and this approximately complies with the Gaussian distribution. This study mainly examines a method to deconvolve the LaBr_3:Ce gamma spectrum with a detector response matrix constructing algorithm based on energy resolution calibration.In the algorithm, the full width at half maximum(FWHM)of full energy peak was calculated by the cubic spline interpolation algorithm and calibrated by a square root of a quadratic function that changes with the energy. Additionally, the detector response matrix was constructed to deconvolve the gamma spectrum. Furthermore, an improved SNIP algorithm was proposed to eliminate the background. In the experiment, several independent peaks of ^(152)Eu,^(137)Cs, and ^(60)Co sources were detected by a LaBr_3:Ce scintillator that were selected to calibrate the energy resolution. The Boosted Gold algorithm was applied to deconvolve the gamma spectrum. The results showed that the peak position difference between the experiment and the deconvolution was within ± 2 channels and the relative error of peak area was approximately within 0.96–6.74%. Finally, a ^(133) Ba spectrum was deconvolved to verify the efficiency and accuracy of the algorithm in unfolding the overlapped peaks.

Optimal Energy-Efficient Transmission for Hybrid Spectrum Sharing in Cooperative Cognitive Radio Networks

In order to improve the energy efficiency(EE)in cognitive radio(CR),this paper investigates the joint design of cooperative spectrum sensing time and the power control optimization problem for the secondary user systems to achieve the maximum energy efficiency in a cognitive network based on hybrid spectrum sharing,meanwhile considering the maximum transmit power,user quality of service(QoS)requirements,interference limitations,and primary user protection.The optimization of energy efficient sensing time and power allocation is formulated as a non-convex optimization problem.The Dinkelbach’s method is adopted to solve this problem and to transform the non-convex optimization problem in fractional form into an equivalent optimization problem in the form of subtraction.Then,an iterative power allocation algorithm is proposed to solve the optimization problem.The simulation results show the effectiveness of the proposed algorithms for energy-efficient resource allocation in the cognitive network.

239Pu alpha spectrum analysis based on PIPS detector response function and variations with vacuum and distance

Effect factors of the absorption of the source,air,entrance window,and dead layer of a detector must be considered in the measurement of monoenergetic alpha particles,along with statistical noise and other factors that collectively cause the alpha spectrum to exhibit a well-known low-energy tail.Therefore,the estabUshment of an alpha spectrum detector response function from the perspective of a signaling system must consider the various factors mentioned above.The detector response function is the convolution of an alphaparticle pulse function,two exponential functions,and a Gaussian function,followed by calculation of the parameters of the detector response function using the weighted leastsquares fitting method as proposed in this paper.In our experiment,^(239)Pu alpha spectra were measured by a highresolution,passivated implanted planar silicon(PIPS)detector at 10 levels of vacuum and 10 source-detector distances.The spectrum-fitting results were excellent as evaluated by reduced Chi-square(x^2) and correlation coefficients.Finally,the variation of parameters with vacuum level and source-detector distance was studied.Results demonstrate that σ,τ_1,and τ_2 exhibit no obvious trend of variation with vacuum in the range 2000-20,000 mTorr,and at a confidence level of 95%,the values of τ_1 and τ_2 decline in a similar fashion with source-detector distance by the power exponential function,while the value of a declines linearly.

Determination of Gamma point source efficiency based on a backpropagation neural network

Efficiency is an important factor in quantitative and qualitative analysis of radionuclides, and the gamma point source efficiency is related to the radial angle,detection distance, and gamma-ray energy. In this work, on the basis of a back-propagation(BP) neural network model,a method to determine the gamma point source efficiency is developed and validated. The efficiency of the point sources ^(137)Cs and ^(60)Co at discrete radial angles, detection distances, and gamma-ray energies is measured, and the BP neural network prediction model is constructed using MATLAB. The gamma point source efficiencies at different radial angles, detection distances, and gamma-ray energies are predicted quickly and accurately using this nonlinear prediction model. The results show that the maximum error between the predicted and experimental values is 3.732% at 661.661 keV, 11π/24, and 35 cm, and those under other conditions are less than 3%. The gamma point source efficiencies obtained using the BP neural network model are in good agreement with experimental data.

A New Arg54Gly Transthyretin Gene Mutation Associated with Vitreous Amyloidosis in Chinese

Purpose:To analyse the hereditary features of a Chinese pedigree with familial vitreous amyloidosis in Liaoning Province,China,and to investigate the correlation between the clinical appearance of the disease and transthyretin(TTR)gene mutation,including the locus and type of TTR gene mutation.Methods:Five patients (10 eyes) from one Chinese family were diagnosed with vitreous amyloidosis between July 1996 and April 2009.Family members were followed up subsequently,and peripheral venous blood was obtained from 13 subjects (including 2 patients,and 11 controls without clinical signs of disease).DNA samples were extracted and 4 exons of the TTR gene were amplified by polymerase chain reaction (PCR).The gene fragments were subjected to sequencing analysis.The results were analyzed with DNAMAN Windows 5.2.2.0 and Chromas sequence chart analysis software,TTR gene exons were compared between affected patients and normal controls.Results:Family pedigree analysis revealed that patients were distributed in three generations.Male and female subjects had equal prevalence,and only one parent of affected patients had signs of disease.TTR gene exon sequencing showed that the sequence of patients was identical to that of normal individuals.No TTR gene mutations were noted in 10 unaffected family members.However,a TTR Gly-54 point mutation in the 2nd exon was detected in two patients and 1 unaffected family member (one of the patients' daughters).Vitreous samples in 4 cases (7 eyes) showed positive Congo red staining,suggesting that these family members suffered from familial vitreous amyloidosis.Conclusion:This pedigree affected with familial vitreous amyloidosis was characterized by autosomal dominant inheritance;.a TTR Gly-54 point mutation in the 2nd exon is presumed to be the cause.This Gly-54 point mutation of the TTR gene is a novel mutation in vitreous amyloidosis.

Unfolding neutron spectra from water-pumping-injection multilayered concentric sphere neutron spectrometer using self-adaptive differential evolution algorithm

A self-adaptive differential evolution neutron spectrum unfolding algorithm(SDENUA)is established in this study to unfold the neutron spectra obtained from a water-pumping-injection multilayered concentric sphere neutron spectrometer(WMNS).Specifically,the neutron fluence bounds are estimated to accelerate the algorithm convergence,and the minimum error between the optimal solution and input neutron counts with relative uncertainties is limited to 10^(-6)to avoid unnecessary calculations.Furthermore,the crossover probability and scaling factor are self-adaptively controlled.FLUKA Monte Carlo is used to simulate the readings of the WMNS under(1)a spectrum of Cf-252 and(2)its spectrum after being moderated,(3)a spectrum used for boron neutron capture therapy,and(4)a reactor spectrum.Subsequently,the measured neutron counts are unfolded using the SDENUA.The uncertainties of the measured neutron count and the response matrix are considered in the SDENUA,which does not require complex parameter tuning or an a priori default spectrum.The results indicate that the solutions of the SDENUA agree better with the IAEA spectra than those of MAXED and GRAVEL in UMG 3.1,and the errors of the final results calculated using the SDENUA are less than 12%.The established SDENUA can be used to unfold spectra from the WMNS.

Identification of differentially expressed genes in ulcerative colitis and verification in a colitis mouse model by bioinformatics analyses

BACKGROUND Ulcerative colitis(UC)is an inflammatory bowel disease that is difficult to diagnose and treat.To date,the degree of inflammation in patients with UC has mainly been determined by measuring the levels of nonspecific indicators,such as C-reactive protein and the erythrocyte sedimentation rate,but these indicators have an unsatisfactory specificity.In this study,we performed bioinformatics analysis using data from the National Center for Biotechnology Information-Gene Expression Omnibus(NCBI-GEO)databases and verified the selected core genes in a mouse model of dextran sulfate sodium(DSS)-induced colitis.AIM To identify UC-related differentially expressed genes(DEGs)using a bioinformatics analysis and verify them in vivo and to identify novel biomarkers and the underlying mechanisms of UC.METHODS Two microarray datasets from the NCBI-GEO database were used,and DEGs between patients with UC and healthy controls were analyzed using GEO2R and Venn diagrams.We annotated these genes based on their functions and signaling pathways,and then protein-protein interactions(PPIs)were identified using the Search Tool for the Retrieval of Interacting Genes.The data were further analyzed with Cytoscape software and the Molecular Complex Detection(MCODE)app.The core genes were selected and a Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis was performed.Finally,colitis model mice were established by administering DSS,and the top three core genes were verified in colitis mice using real-time polymerase chain reaction(PCR).RESULTS One hundred and seventy-seven DEGs,118 upregulated and 59 downregulated,were initially identified from the GEO2R analysis and predominantly participated in inflammation-related pathways.Seven clusters with close interactions in UC formed:Seventeen core genes were upregulated[C-X-C motif chemokine ligand 13(CXCL13),C-X-C motif chemokine receptor 2(CXCR2),CXCL9,CXCL5,C-C motif chemokine ligand 18,interleukin 1 beta,matrix metallopeptidase 9,CXCL3,formyl peptide receptor 1,complement component 3,CXCL8,CXCL1,CXCL10,CXCL2,CXCL6,CXCL11 and hydroxycarboxylic acid receptor 3]and one was downregulated[neuropeptide Y receptor Y1(NYP1R)]in the top cluster according to the PPI and MCODE analyses.These genes were substantially enriched in the cytokinecytokine receptor interaction and chemokine signaling pathways.The top three core genes(CXCL13,NYP1R,and CXCR2)were selected and verified in a mouse model of colitis using real-time PCR Increased expression was observed compared with the control mice,but only CXCR2 expression was significantly different.CONCLUSION Core DEGs identified in UC are related to inflammation and immunity inflammation,indicating that these reactions are core features of the pathogenesis of UC.CXCR2 may reflect the degree of inflammation in patients with UC.

Effects of lipid-lowering agents on diabetic retinopathy: a Meta-analysis and systematic review

AIM：To clarify this controversy and to provide evidence for application of lipid lowering agents in treatment of diabetic retinopathy（DR）.METHODS：We searched the databases of Pub Med,Embase and Cochrane Library Central Register of Controlled Trials（CENTRAL）and abstracts from main annual meetings up to January 1,2017.Google scholar and Clinical Trials.gov were also searched for unpublished relevant studies.We included randomized controlled trials（RCTs）that studied lipid-lowering agents in type 1 or type 2 diabetes in this Meta-analysis.The primary endpoint was the progression of DR,and the secondary endpoints included vision loss,development of diabetic macular edema（DME）and aggravation of hard exudates.The pooled odds ratios（OR）with corresponding 95%confidence intervals（95%CIs）were calculated.RESULTS：After systemic and manual literature search by two independent investigators,we included 8 RCTs from 7 published articles with 13 454 participants in this Meta-analysis.The results revealed that lipid-lowering drugs were associated with reduced risk in DR progression[OR=0.77（95%CI：0.62,0.96）,P=0.02].Lipid-lowering agents might have protective effect on DME compared to placebo,although the difference was not statistically significant[OR=0.60（95%CI：0.34,1.08）,P=0.09].However,no significant differences in the worsening of vision acuity[OR=0.96（95%CI：0.81,1.14）,P=0.64]and hard exudates[OR=0.50（95%CI：0.15,1.74）,P=0.28]were found between the lipidlowering drugs and the placebo groups.CONCLUSION：In DR patients,lipid-lowering agents show a protective effect on DR progression and might be associated with reduced risk in the development of DME.However,lipid-lowering agents have no effects on vision loss and hard exudates aggravation.Further clinical trials in larger scale are required to confirm the conclusion of this study and thus justify the use of intensive control lipids with anti-lipid agents at the early stages of DR.

Evolution and analysis of gas sorption-induced coal fracture strain data

Although coal swelling/shrinking during coal seam gas extraction has been studied for decades,its impacts on the evolution of permeability are still not well understood.This has long been recognized,but no satisfactory solutions have been found.In previous studies,it is normally assumed that the matrix swelling/shrinking strain can be split between the fracture and the bulk coal and that the splitting coefficient remains unchanged during gas sorption.In this study,we defined the fracture strain as a function of permeability change ratio and back-calculated the fracture strains at different states.In the equilibrium state,the gas pressure is steady within the coal;in the non-equilibrium state,the gas pressure changes with time.For equilibrium states,the back-calculated fracture strains are extremely large and may be physically impossible in some case.For non-equilibrium states,two experiments were conducted:one for a natural coal sample and the other for a reconstructed one.For the fractured coal,the evolution of permeability is primarily controlled by the transition of coal fracture strain or permeability from local matrix swelling effect to global effect.For the reconstituted coal,the evolution of pore strain or permeability is primarily controlled by the global effect.

Unusual tunability of multiferroicity in GdMn_2O_5 by electric field poling far above multiferroic ordering point

The multiferroicity in the RMn_2O_5 family remains unclear, and less attention has been paid to its dependence on high-temperature(high-T) polarized configuration. Moreover, no consensus on the high-T space group symmetry has been reached so far. In view of this consideration, one may argue that the multiferroicity of RMn_2O_5 in the low-T range depends on the poling sequence starting far above the multiferroic ordering temperature. In this work, we investigate in detail the variation of magnetically induced electric polarization in GdMn_2O_5 and its dependence on electric field poling routine in the high-T range. It is revealed that the multiferroicity does exhibit qualitatively different behaviors if the high-T poling routine changes, indicating the close correlation with the possible high-T polarized state. These emergent phenomena may be qualitatively explained by the co-existence of two low-T polarization components, a scenario that was proposed earlier.One is the component associated with the Mn^(3+)–Mn^(4+)–Mn^(3+) exchange striction that seems to be tightly clamped by the high-T polarized state, and the other is the component associated with the Gd Mn^(3+)–Mn^(4+)–Mn^(3+) exchange striction that is free of the clamping. The present findings may offer a different scheme for the electric control of the multiferroicity in RMn_2O_5.

Long Term Perinatal Deltamethrin Exposure Alters Electrophysiological Properties of Embryonic Ventricular Cardiomyocyte

Increased use of pyrethroids and the exposure to pyrethroids for pregnant women and children have raised the concerns over the potential effect of pyrethroids on developmental cardiotoxicity and other abnormalities.The purpose of this study was to investigate whether long tenn peri natal deltamethrin exposure altered embryonic cardiac electrophysiology in mice.Pregnant mice were administered with 0 or 3 mg/kg of deltamethrin by gavage daily from gestational day(gd)10.5 to gd 17.5.Whole cell patch-clamp technique was used in electrophysiological study,and real time RT-PCR was applied to analyze the molecular changes for the electrophysiological properties.Deltamethrin exposure resulted in increased mortality of pregnant mice and decreased viability of embryos.Moreover,deltamethrin slowed the maximum depolarization velocity(Vmax),prolonged the action potential duration(APD)and depolarized the maximuin diastolic potential(MDP)of embryonic cardiomyocytes.Additionally,perinatal deltamethrin exposure decreased the mRNA expression of Na^+channel regulatory subunit Navpl,inward rectifier K^+channel subunit Kir2.1,and delayed rectifier K^+channel subunit MERG while the L-type Ca^2+channel subunit,Cavl.2 expression was increased.On the contraiy,deltamethrin administration did not significantly alter the regulation ofβ-adrenergic or muscarinic receptor on embryonic cardiomyocytes.In conclusion,deltamethrin exposure at perinatal stage significantly alters mRNA expression of embryonic cardiac ion channels and therefore influences embryonic cardiac electrophysiological properties.This highlights the need to understand the persistent effects of pyrethroid exposure on cardiac function during embryonic development due to potential for cardiac arrhythmogenicity.

Facet-dependent catalytic activity of two-dimensional Ti_(3)C_(2)T_(x) MXene on hydrogen storage performance of MgH_(2)

Two-dimensional Ti_(3)C_(2)T_(x) MXenes exposing different active facets are introduced into MgH_(2), and their catalytic effects are systematically investigated in depth through experimental and theoretical approaches. Excluding factors such as interlayer space, surface functional groups and experimental contingency, the exposed facets is considered to be the dominant factor for catalytic activity of Ti_(3)C_(2)T_(x) towards MgH_(2).More exposed edge facets of Ti_(3)C_(2)T_(x) displays higher catalytic activity than that with more exposed basal facets, which also leads to different rate-controlling steps of MgH_(2) in the de/hydrogenation process. The low work function, strong hydrogen affinity and high content of in situ metallic Ti for the edge facet contribute the high catalytic activity. This work will give insights into the structural design of two-dimensional Ti_(3)C_(2)T_(x) MXene used for enhancing the catalytic activity in various fields.