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Geochemistry and Sm-Nd systematics of the 1.67 Ga Buanji Group of southwestern Tanzania: Paleo-weathering, provenance and paleo-tectonic setting implications

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Geoscience Frontiers 2017年第5期8卷 1025-1037页

作者： charles h.Kasanzu Makenya A.h.Maboko Shukrani Manya Department of Geology University of Dar es Salaam P.O. Box 35052 Dar es Salaam Tanzania

We present major and trace and Nd-isotopic data of the^1.67 Ga Buanji Group of southwestern Tanzania in order to constrain the nature of their protolith and the intensity of chemical weathering in the source terranes and make inferences on the nature of climatic conditions during the late Paleoproterozoic in the region. Major and trace element contents of the shales from three stratigraphic formations are comparable to those of the post-Archaean Australian Shale(PAAS) and the average Proterozoic Shale(PS). They are characterized by enrichments in LREE relative to hREE((La/Yb)_(CN)=9.07-13.2;(Gd/Yb)cN = 1.51-1.85) and negative Eu anomalies(Eu/Eu~* = 0.61-0.81); features which are comparable to those of PAAS and PS, indicating upper continental sources. Provenance proxy ratios,together with abundances of Cr, Ni, Co and V that increase up-stratigraphy suggest a decreasing input of felsic detritus up-stratigraphy. Chemical Indices of Alteration(CIA) for the lower, middle and upper Buanji formations are 81. 76 and 79, respectively. These indices largely indicate intermediate(ca. 60-80)to extreme(>80) weathering intensities of the precursor rocks. These observations may suggest the prevalence of warm, humid climates during the late Paleoproterozoic in the *** lower Buanji Formation yielded a depleted mantle Nd model age(T_(DM)) of 、2100 Ma which indicates an Eburnean parentage. T_(DM) ages of 2486-2155 Ma and 2535-2379 Ma obtained from middle and upper Buanji formations, respectively, suggest a progressive increase of sedimentary input from the Tanzania Craton up-stratigraphy. The Eburnean T_(DM) ages of the lower Buanji rocks are attributed to their derivation through denudation of a decaying topographic high composed predominantly of rocks that were generated during the Palaeoproterozoic Ubendian orogenesis, possibly in the realm of Columbian Supercontinent assembly. Overlapping T_(DM) ages between the middle and upper Buanji formations suggest multiple sources i

关键词： Buanji Group Shales Source weathering conditions Provenance

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Afforestation,restoration and regeneration——Not all trees are created equal

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Journal of Forestry Research 2014年第1期25卷 3-20页

作者： Shaneka S.Lawson charles h.Michler USDA Forest Service Northern Research StationHardwood Tree Improvement and Regeneration Center (HTIRC)Purdue UniversityDepartment of Forestry and Natural Resources

Undulations in weather patterns have caused climate shifts of increased frequency and duration around the world. The need for additional research and model data on this pressing problem has resulted in a plethora of research groups examining a particular tree species or biome for negative effects of climate change. This review aims to （1） collect and merge recent research data on regeneration within old- and new-growth forests, （2） highlight and expand upon selected topics for additional discussion, and （3） report how shade tolerance, drought toler- ance, and inherent plasticity affect tree growth and development. Al- though shade and drought tolerance have been well studied by a number of research groups, this review reveals that in-depth analysis of a single or a few species in a given area will not generate the data required to implement a successful regeneration plan. Studies using historical accounts of previous species composition, information regarding site sea- sonality, species competition, and individual responses to drought and shade are needed to （1） develop best management plans and （2） ensure future modeling experiments are focused on a greater variety of species using more innovative methods to evaluate climate change effects.

关键词： Climate change shade tolerance drought tolerance canopy gaps invasive species

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New methods of safety evaluation for rock/soil mass surrounding tunnel under earthquake

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Journal of Central South University 2014年第7期21卷 2935-2943页

作者：程选生 DOWDING charles h 田瑞瑞 School of Civil Engineering Lanzhou University of Technology Department of Civil and Environmental Engineering Northwestern University Key Laboratory of Urban Security and Disaster Engineering of Education Ministry Beijing University of Technology

The objective of this work is to obtain the seismic safety coefficient and fracture surface and proceed with the seismic safety evaluation for the rock mass or soil mass surrounding a tunnel,and the limitation of evaluating seismic stability is considered using the pseudo-static strength *** using the finite element software ANSYS and the strength reduction method,new methods of seismic safety evaluation for the rock mass or soil mass surrounding a tunnel are put forward,such as the dynamic finite element static shear strength reduction method and dynamic finite element shear strength reduction *** order to prove the feasibility of the proposed methods,the results of numerical examples are compared with that of the pseudo-static strength reduction *** results show that 1) the two methods are both feasible,and the plastic zone first appears near the bottom corners; 2) the safety factor of new method Ⅱ is smaller than that of new method I but generally,and the difference is very ***,in order to ensure the safety of the structure,two new methods are proposed to evaluate the seismic stability of the rock mass or soil mass surrounding a tunnel.A theoretical basis is provided for the seismic stability of the rock mass or soil mass and the lining surrounding a tunnel and also provided for the engineering application.

关键词： tunnel rock or soil mass surrounding tunnel earthquake stability safety evaluation

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Isotretinoin for the treatment of nonobstructive azoospermia: a pilot study

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Asian Journal of Andrology 2021年第5期23卷 537-540页

作者： John K Amory charles h Muller Thomas J Walsh Department of Medicine University of WashingtonSeattleWA 98195USA Department of Urology University of WashingtonSeattleWA 98195USA

The treatment of men with infertility from azoospermia is *** some men with severe oligozoospermia improve sperm output during treatment with isotretinoin,we treated nine men with azoospermia with isotretinoin to determine if azoospermic men would also respond to isotretinoin *** of these men who had a previous negative testicular sperm extraction(TESE)was found to have an area of sperm production on a postisotretinoin testicular *** man achieved a pregnancy and a live birth of a healthy,term daughter after in vitro fertilization coupled with intracytoplasmic sperm injection(IVF/ICSI).A second subject had a positive TESE after treatment as *** study of isotretinoin therapy in men with azoospermia undergoing testicular sperm harvesting procedures is warranted.

关键词： treatment injection pregnancy

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Phase-field modeling of void evolution and swelling in materials under irradiation

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Science China(Physics,Mechanics & Astronomy) 2011年第5期54卷 856-865页

作者： hENAGER charles h Jr KhALEEL Mohammad Pacific Northwest National Laboratory Richland WA 99352 USA

Void swelling is an important phenomenon observed in both nuclear fuels and cladding materials in operating nuclear reactors. In this work we develop a phase-field model to simulate void evolution and void volume change in irradiated materials. Important material processes, including the generation of defects such as vacancies and self-interstitials, their diffusion and annihilation, and void nucleation and evolution, have been taken into account in this model. The thermodynamic and kinetic properties, such as chemical free energy, interfacial energy, vacancy mobility, and annihilation rate of vacancies and interstitials, are expressed as a function of temperature and/or defect concentrations in a general manner. The model allows for parametric studies of critical void nucleus size, void growth kinetics, and void volume fraction evolutions. Our simulations demonstrated that void swelling displays a quasi-bell shape distribution with temperature often observed in experiments.

关键词： radiation void swelling vacancies interstitials phase-field model

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Cross-specific amplification of microsatellite DNA markers in Shorea platyclados

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Journal of Forestry Research 2016年第1期27卷 27-32页

作者： Asif J.Muhammad charles h.Cannon Wickneswari Ratnam Department of Biological Sciences Texas Tech University Faculty of Science and Technology School of Environmental and Natural Resource SciencesUniversiti Kebangsaan Malaysia

In the megadiverse forests of Southeast Asia, hundreds of timber species are economically important but the population genetics of only a few taxa are known. Cross-specific amplification of microsatellite loci among closely related taxa could enhance our ability to study and manage previously unstudied species. We successfully utilized STMS markers in Shorea platyclados, originally developed for Shorea curtisii. The six primer pairs we tried successfully produced PCR products of expected sizes. The number of alleles observed ranged from 10 to 14 and an average of 12 alleles were detected per locus. A high expected and observed heterozygosity was observed and it ranges from 0.718 to 0.827 among all populations across all six loci tested. Microsatellite DNA markers are highly polymorphic, co-dominant, reproducible, and amenable to high throughput genetic analyses. Overall, the cross- specific amplification of microsatellite loci appears to be complicated by numerous factors. While the approach may be effective for local management and conservation ofpoorly known species, the results must be carefully interpreted.

关键词： Genetic marker systems Populationgenetics SSR Selective logging Tropical timber Capillary electrophoresis

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The dynamics of adult neurogenesis in human hippocampus

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Neural Regeneration Research 2016年第12期11卷 1869-1883页

作者： Amadi O.Ihunwo Lackson h.Tembo charles Dzamalala School of Anatomical Sciences Faculty of Health SciencesUniversity of the Witwatersrand

The phenomenon of adult neurogenesis is now an accepted occurrence in mammals and also in *** least two discrete places house stem cells for generation of neurons in adult brain. These are olfactory system and the hippocampus. In animals, newly generated neurons have been directly or indirectly demonstrated to generate a significant amount of new neurons to have a functional role. however, the data in humans on the extent of this process is still scanty and such as difficult to comprehend its functional role in humans. This paper explores the available data on as extent of adult hippocampal neurogenesis in humans and makes comparison to animal data.

关键词： adult neurogenesis neuron neuronal stem cell proliferation differentiation neuronal turn-over hippocampus human neurogenesis

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Comparative chemical sensor for detection of chromium(Ⅵ) in aqueous solution

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Optoelectronics Letters 2025年第1期21卷 21-27页

作者： Sura h.AL-REKABI A.A.ALWAhIB Electrical Technique Department Al Suwayrah Technical Institute Middle Technical University Laser and Optoelectronics Department University of Technology-Iraq

A process for purifying aqueous solutions containing heavy and toxic metals such as chromium（Cr） has been investigated. One of the extremely harmful pollutants in rivers and seawater is the heavy metal ions due to their direct impacts on human, animals and plants are hexavalent Cr（Ⅵ）. Consequently, highly sensitive sensor to detect Cr is essential. Surface plasmon resonance（SPR） technique has attracted huge research interest in detecting heavy metals specifically. In this study, three types of prism-based SPR sensor, gold（Au）/silver（Ag）, Au/polyaniline（PANI） and Au/titanium dioxide（TiO2） nanostructured films, are investigated as potential sensing material to detect the presence of Cr（Ⅵ） ions in water. The base Au layer with thickness of 48.3 nm is deposited on a glass slide for all sensors. For Au/Ag, Au/PANI nanofibers and Au/TiO2sensor films, the Cr（Ⅵ） concentration is varied from 1 ppm to 15 ppm with sensitivity of 0.270 °ppm-1, 0.082 °ppm-1and 0.039 °ppm-1, respectively. Based on these results, the Au/PANI nanofibers are the most sensitive to Cr（Ⅵ） among the tested sensing materials.

关键词： Titanium dioxide

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Post-transcriptional regulation of vascular endothelial growth factor: Implications for tumor angiogenesis

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World Journal of Gastroenterology 2006年第31期12卷 4937-4942页

作者： Peter S Yoo Abby L Mulkeen charles h Cha Gastrointestinal Surgery and Surgical OncologyYale School of Medicine New HavenConnecticutUnited States

Vascular endothelial growth factor （VEGF） is a potent secreted mitogen critical for physiologic and tumor angiogenesis. Regulation of VEGF occurs at several levels, including transcription, mRNA stabilization, translation, and differential cellular localization of various isoforms. Recent advances in our understanding of post-transcriptional regulation of VEGF include identification of the stabilizing mRNA binding protein, huR, and the discovery of internal ribosomal entry sites in the 5＇UTR of the VEGF mRNA. Monoclonal anti-VEGF antibody was recently approved for use in humans, but suffers from the need for high systemic doses. RNA interference （RNAi） technology is being used in vitro and in animal models with promising results. here, we review the literature on post-transcriptional regulation of VEGF and describe recent progress in targeting these mechanisms for therapeutic benefit.

关键词： Vascular endothelial growth factor Vascular endothelial growth hormone Post-transcriptional regulation mRNA stability huR ELAVl Internal ribosomal entry IRES siRNA RNAi Bevacizumab

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A segmental defect adaptation of the mouse closed femur fracture model for the analysis of severely impaired bone healing

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Animal Models and Experimental Medicine 2020年第2期3卷 130-139页

作者： Amandeep Kaur Subburaman Mohan charles h.Rundle Musculoskeletal Disease Center Research Service(151)Jerry L.Pettis Memorial Veterans Administration Medical CenterLoma LindaCAUSA Department of Medicine Loma Linda UniversityLoma LindaCAUSA Department of Orthopedic Surgery Loma Linda UniversityLoma LindaCAUSA

Objective: To better characterize nonunion endochondral bone healing and evaluate novel therapeutic approaches for critical size defect healing in clinically challenging bone repair, a segmental defect model of bone injury was adapted from the threepoint bending closed fracture technique in the murine ***: The mouse femur was surgically stabilized with an intramedullary threaded rod with plastic spacers and the defect adjusted to different sizes. healing of the different defects was analyzed by radiology and histology to 8 weeks postsurgery. To determine whether this model was effective for evaluating the benefits of molecular therapy, BMP-2 was applied to the defect and healing then ***: Intramedullary spacers were effective in maintaining the defect. Callus bone formation was initiated but was arrested at defect sizes of 2.5 mm and above, with no more progress in callus bone development evident to 8 weeks healing. Cartilage development in a critical size defect attenuated very early in healing without bone development, in contrast to the closed femur fracture healing, where callus cartilage was replaced by bone. BMP-2 therapy promoted osteogenesis of the resident cells of the defect, but there was no further callus development to indicate that healing to pre-surgery bone structure was ***: This segmental defect adaptation of the closed femur fracture model of murine bone repair severely impairs callus development and bone healing, reflecting a challenging bone injury. It is adjustable and can be compared to the closed fracture model to ascertain healing deficiencies and the efficacy of therapeutic approaches.

关键词： bone fractures bone morphogenetic protein 2 intramedullary fracture fixation ununited fractures

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