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Stem cell therapy for the treatment of Leydig cell dysfunction in primary hypogonadism

World Journal of Stem cells 2016年第10期8卷 306-315页

作者： taylor c peak Nora M Haney William Wang Kenneth J DeLay Wayne J Hellstrom Department of Urology School of MedicineTulane University

The production of testosterone occurs within the Leydig cells of the testes. When production fails at this level from either congenital, acquired, or systemic disorders,the result is primary hypogonadism. While numerous testosterone formulations have been developed, none are yet fully capable of replicating the physiological patterns of testosterone secretion. Multiple stem cell therapies to restore androgenic function of the testes are under investigation. Leydig cells derived from bone marrow, adipose tissue, umbilical cord, and the testes have shown promise for future therapy for primary hypogonadism. In particular, the discovery and utilization of a group of progenitor stem cells within the testes, known as stem Leydig cells(SLcs), has led not only to a better understanding of testicular development, but of treatment as well. When combining this with an understanding of the mechanisms that lead to Leydig cell dysfunction, researchers and physicians will be able to develop stem cell therapies that target the specific step in the steroidogenic process that is deficient. The current preclinical studies highlight the complex nature of regenerating this steroidogenic process and the problems remain unresolved. In summary, there appears to be two current directions for stem cell therapy in male primary hypogonadism. The first method involves differentiating adult Leydig cells from stem cells of various origins from bone marrow, adipose, or embryonic sources. The second method involves isolating, identifying, and transplanting stem Leydig cells into testicular tissue. Theoretically, in-vivo re-activation of SLcs in men with primary hypogonadism due to age would be another alternative method to treat hypogonadism while eliminating the need for transplantation.

关键词： Stem cell therapy Leydig cells Primary hypogonadism Stem Leydig cells Testosterone Bone marrow-derived stem cells Adipose-derived mesenchymal stem cells

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Revealing interfacial charge redistribution of homologous Ru-RuS_(2) heterostructure toward robust hydrogen oxidation reaction

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Journal of Energy chemistry 2024年第7期94卷 332-339页

作者： Yi Liu Lianrui cheng Shuqing Zhou Yuting Yang chenggong Niu Tayirjan taylor Isimjan Bao Wang Xiulin Yang Guangxi Key Laboratory of Low carbon Energy Materials School of Chemistry and Pharmaceutical SciencesGuangxi Normal UniversityGuilin 541004GuangxiChina State Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China Saudi Arabia Basic Industries corporation(SABIc)at King Abdullah University of Science and Technology(KAUST) Thuwal 23955-6900Saudi Arabia

Precisely tailoring the surface electronic structures of electrocatalysts for optimal hydrogen binding energy and hydroxide binding energy is vital to improve the sluggish kinetics of hydrogen oxidation reac-tion(HOR).Herein,we employ a partial desulfurization strategy to construct a homologous Ru-RuS_(2) heterostructure anchored on hollow mesoporous carbon nanospheres(Ru-RuS_(2)@c).The disparate work functions of the heterostructure contribute to the spontaneous formation of a unique built-in electric field,accelerating charge transfer and boosting conductivity of ***,Ru-RuS_(2)@c exhibits robust HOR electrocatalytic activity,achieving an exchange current density and mass activity as high as 3.56 mA cm^(-2) and 2.13 mAμg_(Ru)^(-1),*** those of state-of-the-art Pt/c and most contemporary Ru-based HOR ***,Ru-RuS_(2)@c can tolerate 1000 ppm of cO that lacks in Pt/*** analysis reveals that the directional electron transfer across Ru-RuS_(2) heterointerface induces local charge redistribution in interfacial region,which optimizes and balances the adsorption energies of H and OH species,as well as lowers the energy barrier for water formation,thereby promoting theHoR performance.

关键词： Heterostructure Hollow spherical structure Hydrogen oxidation reaction charge redistribution Density functional calculation

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Attenuated retinoic acid signaling is among the early responses in mouse uterus approaching embryo attachment

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生殖与发育医学(英文) 2024年第1期08卷 61-65页

作者： Diao Honglu Xiao Shuo Zhou Tong Martin taylor E. Watford Wendy T. Ye Xiaoqin Department of Infectious Diseases Department of Physiology and Pharmacology college of Veterinary Medicine 3. University of Georgia 4. Athens 5. GA 30602 6. USA Department of Physiology and cell Biology University of Nevada 9. Reno School of Medicine 10. Reno 11. NV 89557

The uterus is transiently receptive for embryo implantation. It remains to be understood why the uterus does not reject a semi-allogeneic embryo (to the biological mother) or an allogeneic embryo (to a surrogate) for implantation. To gain insights, we examined uterine early response genes approaching embryo attachment on day 3 post coitum (D3) at 22 hours when blue dye reaction, an indication of embryo attachment, had not manifested in mice. c57BL/6 pseudo-pregnant (control) and pregnant mouse uteri were collected on D3 at 22 hours for microarray analysis. The self-assembling-manifold (SAM) algorithm identified 21,858 unique probesets. Principal component analysis indicated a clear separation between the pseudo-pregnant and pregnant groups. There were 106 upregulated and five downregulated protein-coding genes in the pregnant uterus with fold change (fc) >1.5 andq value cant GO biological process (GOBP) terms (P ciated with immune responses, with a dominant natural killer (NK) cell activation signature. Among the top eight upregulated protein-coding genes,cyp26a1 inactivates retinoic acid (RA) whileLrat promotes vitamin A storage, both of which are expected to attenuate RA bioavailability;Atp6v0d2 andGjb2 play roles in ion transport and transmembrane transport;Gzmb,Gzmc, andIl2rb are involved in immune responses; andTdo2 is important for kynurenine pathway. Most of these genes or their related pathways have functions in immune regulations. RA signaling has been implicated in immune tolerance and immune homeostasis, and uterine NK cells have been implicated in immunotolerance at the maternal-fetal interface in the placenta. The mechanisms of immune responses approaching embryo attachment remain to be elucidated. The coordinated effects of the early response genes may hold the keys to the question of why the uterus does not reject an implanting embryo

关键词： Embryo attachment Pseudo-pregnant uterus Pregnant uterus Natural killer cell activation signature Retinoic acid bioavailability Transmembrane transport and ion transport

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构筑富含磷空位缺陷的磷化钯催化剂实现高效和抗cO毒化的碱性氢氧化反应

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chinese Journal of catalysis 2024年第1期56卷 176-187页

作者：杨玉婷石路岩梁沁睿刘奕董家新 Tayirjan taylor Isimjan 王宝杨秀林广西师范大学化学与药学学院广西低碳能源材料重点实验室中国广西桂林541004 中山大学环境科学与工程学院中国广东广州510275 中国科学院过程工程研究所生化工程国家重点实验室中国北京100190 阿卜杜拉国王科技大学的沙特阿拉伯基础工业公司图瓦勒沙特阿拉伯

碱性阴离子交换膜燃料电池(AEMFcs)可以直接将氢的化学能转化为电能,被认为是新兴绿色氢经济的基石技术.但其阳极氢氧化反应(HOR)动力学缓慢,严重依赖于Pt基催化剂.由于Pt基催化剂极易被cO毒化、动力学过程复杂以及价格昂贵,极大限制了... 详细信息

碱性阴离子交换膜燃料电池(AEMFcs)可以直接将氢的化学能转化为电能,被认为是新兴绿色氢经济的基石技术.但其阳极氢氧化反应(HOR)动力学缓慢,严重依赖于Pt基催化剂.由于Pt基催化剂极易被cO毒化、动力学过程复杂以及价格昂贵,极大限制了其商业化应用.因此,亟需开发高效、稳定和抗cO毒化能力强的新型HOR催化剂.Pd具有与Pt相似的氢键结合能,并且比Pt储量丰富,有望成为实现HOR的候选催化剂.然而,Pd的本征催化活性和Pt相比仍有很大差距.近年来,磷化钯因具有功能多样性和高催化活性被广泛关注.此外,缺陷工程可以有效调控催化剂的表面结构,改善中间体的吸附强度,提高催化剂的催化活性.因此,构建富含缺陷的磷化钯催化剂有望提高其HOR的性能.然而,该方向研究较少,反应机理尚不清楚.因此,阐明空位缺陷对于提高磷化钯催化剂HOR性能的作用机制,对促进AEMFcs电催化反应具有重要意义.本文通过溶胶-凝胶法以及低温磷化策略合成了一种碗状半球结构的富含磷空位Pd3P@c(V_(p)-Pd_(3)P@c)催化剂,并用于碱性HOR.在磷化过程中,通过调整Pd前驱体和磷源比例以及煅烧温度,在碳碗状半球载体上合成具有不同晶相组成(Pd/Pd_(3)P@c,Pd_(3.20)P_(12)@c,Pd_(3)P@c,和Pd_(5)P_(2)@c)的Pd_(x)P_(y)@c催化剂.扫描电镜和透射电镜证实了催化剂为碗状半球形貌.利用电子顺磁共振波谱研究了Pd_(x)P_(y)@c催化剂的磷空位浓度,结果表明,Pd/P比例为1:3时,在350℃下煅烧得到的Vp-Pd_(3)P@c具有最高的磷空位浓度.X射线光电子能谱证实了磷空位促进了d-p轨道杂化,增强了Pd和磷之间的电子相互作用.电化学测试结果表明,Vp-Pd_(3)P@c具有最高的HOR性能,Vp-Pd_(3)P@c在50 mV的质量活性为1.66 mAμg_(Pd)^(–1),交换电流密度为3.2 mA cm^(–2),优于Pd3P(0.45 mAμg_(Pd)^(-1),1.78 mA cm^(–2))和商业Pt/c(0.3 mAμg_(Pd)^(-1),2.29 mA cm^(–2)).同时,该催化剂在50 mV的电位下能稳定运行20 h.此外,即使在cO浓度高达1000 ppm时,Vp-Pd_(3)P@c催化剂仍表现出较好的HOR活性.紫外光电子能谱证实了Vp-Pd_(3)P@c中的Pd原子呈现缺电子状态,这不利于Pd 4d轨道对cO 2π^(*)轨道的电子反馈,降低了Pd和cO的键合强度,进而减弱了Pd对cO分子的吸附,从而增强了其抗cO中毒的能力.密度泛函理论计算结果表明,相较于磷空位浓度较少的Pd_(3)P@c催化剂,富含磷空位缺陷的Vp-Pd_(3)P@c催化剂能够优化和平衡反应中间体(Hads和OHads)的吸附强度,使速率决定步骤从H_(2)O^(*)的解吸转换到H_(2)O的形成,促进了Volmer反应(Hads+OHads→H_(2)O+2^(*)sites)的进行,进而提升了催化活性.系统实验和表征结果表明,Vp-Pd_(3)P@c较好的HOR性能可归因于以下3个因素:(1)空心碗状结构大大地增加了固-液-气三相接触点,加速了HOR的传质过程;(2)磷空位产生的局部反应活性和有利的电子结构优化了Hads和OHads的吸附强度,极大地促进了Volmer步骤;(3)丰富的磷空位打破了原有的周期性晶体结构,形成了新的电子结构,有效地抑制了电子从Pd 4d轨道到cO 2π^(*)轨道的反馈,提高了Vp-Pd_(3)P@c对cO的耐受能力.综上,本文通过缺陷工程策略调控了Vp-Pd_(3)P@c中活性位点与HOR关键中间体的相互作用,明确了空位缺陷浓度与HOR活性之间的构效关系.并从碱性HOR反应机理,cO分子与金属催化剂的轨道相互作用以及结构设计三个方面总结了高效和稳定的HOR催化剂的设计原则.目前,由于界面环境的复杂性和缺乏原位技术,催化剂表面上痕量中间体的光谱信息难以获得,未来可在开发原位技术监测HOR过程中间体和催化剂的组分变化方面做出更多的努力,以促进AEMFcs的商业化应用.

关键词：氢氧化反应 cO耐受性磷空位 V_(p)-Pd_(3)P@c 碗状半球

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Thermoluminescence characterization of natural and synthetic irradiated ce-monazites

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Journal of Rare Earths 2024年第4期42卷 643-650页

作者： V.correcher c.Boronat J.Garcia-Guinea J.F.Benavente T.Rivera-Montalvo cIEMAT Av.Complutense 4028040MadridSpain MNcN-cSIc J.Gutierrez Abascal 228006MadridSpain Instituto Politécnico Nacional CICATA-IPNAv.Legaria 694Mexico City11500Mexico

The thermoluminescence(TL)emission of synthetic and natural ce-monazites was characterized here to determine the potential application in the identification of microscopic defects from a qualitative point of view trying to link each TL peak to a chemical-physical *** kinetic parameters that lead the luminescence processes were calculated by means of variable heating rate and computing glow curve deconvolution methods and allow identifying three groups of components at~90,130 and 290℃(for the mineral sample)and~90,170,220,270 and 320℃(for the synthetic cePO_(4):Nd_(0.20),La_(0.25)).The main differences appreciated in these complex TL curves are mainly due to(i)the content of impurities(natural sample contains lanthanides as well as U 0.60%and Th 5.22%)and(ii)the degree of crystallinity of the samples which is directly related to the type of impurities(synthetic monazite relies only on Nd and La).The behavior of the dose response in the range of 1-8 Gy is similar for both samples;the TL intensity increases linearly as the dose increases without changes in the position of the maxima,denoting first-order kinetic luminescence *** peak could be mostly associated with structural defects(i.e.,phase transitions),chemical reactions(i.e.,ce3+?ce4+redox reaction,dehydration or dehydroxylation processes)or intrinsic defects(i.e.,Frenkel defects,ODcs or NBOHcs).

关键词： Thermoluminescence Kineticparameters Phosphate ce-monazite Defects Rare earths

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Impact of carbon-based nutrient enhancement on biofiltration performance for drinking water treatment

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Journal of Environmental Sciences 2019年第8期31卷 124-131页

作者： Yu Zhao Liz taylor-Edmonds Robert c.Andrews Department of civil and Mineral Engineering University of Toronto

Incorporation of a carbon-based nutrient enhancementstrategy for drinking water biofiltration is an attractive option, especially for source waters which contain recalcitrant organics. This study compared biofilters that were operated in parallel and individually enhanced with amino acids(including alanine, phenylalanine, and tryptophan), inulin, and sucrose to increase biomass concentration and promote biodegradation of dissolved organic carbon(DOc) in the source water, including disinfection by-product(DBP) precursors. Biomass activity was characterized by measuring adenosine tri-phosphate(ATP), dissolved oxygen(DO) consumption, and through the use of laccase and esterase enzyme assays. Performance was evaluated in terms of headloss,turbidity, p H, DOc, UV254, and DBP formation potential(DBP FP). The introduction of carbonbased nutrients significantly increased biomass activity, where ATP values peaked at 976 ng/g of filter media, 853 ng/g, and 513 ng/g for amino acids, inulin, and sucrose-spiked biofilters,respectively, while a non-spiked control only reached 104 ng/g. DO utilization by the enhanced biofilters was significantly higher than the control, with a strong correlation between ATP and DO uptake observed for all filters(R^2> 0.74). Laccase and esterase enzyme activities of enhanced biofilters were also elevated(p > 0.05), suggesting greater biodegradation potential. Operational parameters such as headloss development and turbidity control were not impaired by carbon supplementation strategies or an increase in biomass concentration and activity. However, the enhancement strategy did not provide improvement in terms of source water carbon removal(DOc and UV254) or DBP FP when treated filters were compared to a control.

关键词： Biological filtration carbon enhancement Biomass Disinfection by-products Dissolved organic carbon

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Inter-signal interaction and uncertain information in anuran multimodal signals

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current Zoology 2011年第2期57卷 153-161页

作者： Ryan c. taylor Barrett A. KLEIN Michael J. RYAN Department of Biological Sciences Salisbury University Salisbury MD 21801 USA Section of Integrative Biology University of Texas at Austin Austin TX 78712 USA Smithsonian Tropical Research Institute P.O. Box 0843-03092 Balboa Ancon Republic of Panama

Disentangling the influence of multiple signal components on receivers and elucidating general processes influencing complex signal evolution are difficult tasks. In this study we test mate preferences of female squirrel treefrogs Hyla squirella and female tungara frogs Physalaemus pustulosus for similar combinations of acoustic and visual components of their multimodal courtship signals. In a two-choice playback experiment with squirrel treefrogs, the visual stimulus of a male model significantly increased the attractivness of a relatively unattractive slow call rate. A previous study demonstrated that faster call rates are more attractive to female squirrel treefrogs, and all else being equal, models of male frogs with large body stripes are more attractive. In a similar experiment with female tungara frogs, the visual stimulus of a robotic frog failed to increase the attractiveness of a relatively unattractive call. Females also showed no preference for the distinct stripe on the robot that males commonly bear on their throat. Thus, features of conspicuous signal components such as body stripes are not universally important and signal function is likely to differ even among species with similar ecologies and communication systems. Finally, we discuss the putative information content of anuran signals and suggest that the categorization of redundant versus multiple messages may not be sufficient as a general explanation for the evolution of multimodal signaling. Instead of relying on untested assumptions concerning the information content of signals, we discuss the value of initially collecting comparative empirical data sets related to receiver responses.

关键词： Inter-signal interaction Multimodal signaling Signal detection Signal weighting Squirrel treefrog Hyla squirella Tfingara frog Physalaemus pustulosus Vocal sac

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Modeling glacio-hydrological processes in the Himalayas:A review and future perspectives

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Geography and Sustainability 2024年第2期5卷 179-192页

作者： Lei Wang Hu Liu Ranjeet Bhlon Deliang chen Junshui Long Tenzing c.Sherpa State Key Laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China University of chinese Academy of Sciences Beijing 100049China Regional climate Group Department of Earth SciencesUniversity of GothenburgGothenburgS-40530(Box 460)Sweden International centre for Integrated Mountain Development Lalitpur 44700Nepal

The Himalayas and their surrounding areas boast vast glaciers rivaling those in polar regions,supplying vital meltwater to the Indus,Ganges,and Brahmaputra rivers,supporting over a billion downstream inhabitants for drinking,power,and *** changing runoff patterns due to accelerated glacial melt,understanding and projecting glacio-hydrological processes in these basins is *** review assesses the evolution,applications,and key challenges in diverse glacio-hydrology models across the Himalayas,varying in complexities like ablation algorithms,glacier dynamics,ice avalanches,and *** findings indicate higher glacial melt contributions to annual runoff in the Indus compared to the Ganges and Brahmaputra,with anticipated peak melting in the latter basins—having less glacier cover—before the mid-21st century,contrasting with the delayed peak expected in the Indus Basin due to its larger glacier *** modeling studies still have large uncertainties in the simulated runoff components in the Himalayan basins;and the projections of future glacier melt peak time vary at different Himalaya sub-basins under different coupled Model Intercomparison Project(cMIP)*** also find that the lack of reliable meteorological forcing data(particularly the precipitation errors)is a major source of uncertainty for glacio-hydrological modeling in the Himalayan ***,permafrost degradation compounds these challenges,complicating assessments of future freshwater *** measures include establishing comprehensive in situ observations,innovating remote-sensing technologies(especially for permafrost ice monitoring),and advancing glacio-hydrology models to integrate glacier,snow,and permafrost *** endeavors are crucial for informed policymaking and sustainable resource management in this pivotal,glacier-dependent ecosystem.

关键词： Glacio-hydrology Modeling Himalayas Glacier,snow,and permafrost Sustainable development

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Immunogenetic phenotypes in inflammatory bowel disease

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World Journal of Gastroenterology 2006年第23期12卷 3645-3650页

作者： Maria c Dubinsky Kent taylor Stephan R Targan Jerome I Rotter Departments of Pediatrics Medicine and Medical Genetics InstituteCedars-Sinai Medical CenterLos Angeles CAUnited States

The currently accepted etiopathogenic hypothesis suggests that the chronic intestinal inflammation and related systemic manifestations characteristic of inflammatory bowel disease （IBD） are due to an overly aggressive or pathologic immune response to resident luminal bacterial constituents. Predisposing factors are genetic dysregulation of mucosal immune responses and/ or barrier function, with onset triggered by environmental stimuli. These factors and their interactions may also be important determinants of disease phenotype and disease progression. The emergence of immunogenetic phenotypes lends support to the proposed hypothesis that susceptibility genes regulate distinct immune processes, driven by luminal antigens, expressed as specific immune phenotypes which in turn influence clinical phenotypes in IBD patient.

关键词： Inflammatory bowel disease Immunereactivity Disease phenotype

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Heterotrophic ammonium removal characteristics of an aerobic heterotrophic nitrifying-denitrifying bacterium, Providencia rettgeri YL

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Journal of Environmental Sciences 2009年第10期21卷 1336-1341页

作者： taylor Shauna M School of Environmental Science and Engineering Shanghai Jiao Tong University

Bacterium Providencia rettgeri YL was found to exhibit an unusual ability to heterotrophically nitrify and aerobically denitrify various concentrations of ammonium （NH4^＋-N）. In order to further understand its removal ability, several experiments were conducted to identify the growth and ammonium removal response at different carbon to nitrogen （c/N） mass ratios, shaking speeds, temperatures, ammonium concentrations and to qualitatively verify the production of nitrogen gas using gas chromatography techniques. Results showed that under optimum conditions （c/N 10, 30℃, 120 r/min）, YL can significantly remove low and high concentrations of ammonium within 12 to 48 h of growth, respectively. The nitrification products hydroxylamine （NHzOH）, nitrite （NO2^-） and nitrate （NO3^-） as well as the denitrification product, nitrogen gas （N2）, were detected under completely aerobic conditions.

关键词： Providencia rettgeri YL heterotrophic ammonium removal aerobic denitrification

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