检索结果-南通市图书馆

Granular titanite from the Roter Kamm crater in Namibia:Product of regional metamorphism,not meteorite impact

Geoscience Frontiers 2022年第3期13卷 156-163页

作者： Aaron j.Cavosie christopher j.Spencer Noreen Evans Kai Rankenburg Robert j.Thomas Paul H.Macey Space Science and Technology Centre and The Institute for Geoscience Research School of Earth and Planetary ScienceCurtin UniversityPerthWA 6102Australia Dept.of Geological Sciences and Geological Engineering Queen’s UniversityOntarioCanada john de Laeter Centre Curtin UniversityPerthWA 6102Australia Council for Geoscience BellvilleWestern CapeSouth Africa

Accessory minerals with so-called granular texture have risen in importance as geochronological tools for U-Pb dating of meteorite impact events. Grain-scale recrystallization, typically triggered by a combination of high-strain deformation and post-impact heating, can create a polycrystalline microstructure consisting of neoblasts that expel radiogenic Pb, which are thus ideal for isotopic dating. While granular domains in zircon and monazite from shocked rocks have been demonstrated to preserve impact ages,few U-Pb dating studies have been conducted on granular microstructures in titanite(CaTiSiO;). Here we report the occurrence of granular-textured titanite from ~2020 Ma granite basement rock exposed in the rim of the 4–5 Ma Roter Kamm impact structure in Namibia. Orientation mapping reveals two microstructurally distinct titanite populations: one consisting of strained/deformed grains, and the other consisting of grains that comprise aggregates of strain-free neoblasts. In situ U-Pb geochronology on 37 grains shows that most grains from both titanite populations yield indistinguishable U-Pb dates of ca.1025 Ma, consistent with the observed microstructures forming during the Mesoproterozoic Namaqua Orogeny. Only four grains preserved older age domains, recording ca. 1875 Ma Paleoproterozoic metamorphism. Two significant observations emerge:(1) none of the analyzed titanite grains yield the 2020 Ma igneous crystallization age previously established from zircon in the same sample, and(2) no age-resetting was detected that could be attributed to the 4 to 5 Ma Roter Kamm impact *** the similarity of the neoblastic microstructure to minerals from other sites with an established impact provenance, the granular texture and near-complete Pb-loss in titanite from Roter Kamm granite instead records a Paleo-to Mesoproterozoic polymetamorphic history, rather than Miocene age shockrelated processes. These results highlight the critical importance of grain-scale cont

关键词： Namibia Roter Kamm Titanite EBSD Geochronology

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

IgG and fibrinogen driven nanoparticle aggregation

引用

Nano Research 2015年第8期8卷 2733-2743页

作者： Risto Cukalevski Silvia A. Ferreira christopher j. Dunning Tord Berggard Tommy Cedervall Department of Biochemistry and Structural Biology Centre for Molecular Protein Science Chemical Centre Lund University PO Box 124 SE-22100 Lund Sweden Centre for Biological Engineering University of Minho Campus Gualtar 4710-057 Braga Portugal Neuronal Survival Unit Department of Experimental Medical Science Wallenberg Neuroscience Center Lund University BMC B 11 22184 Lund Sweden Alligator Bioscience AB Lund Sweden

A thorough understanding of how proteins induce nanoparticle （NP） aggregation is crucial when designing in vitro and in vivo assays and interpreting experimental results. This knowledge is also crucial when developing nano-applications and formulation for drug delivery systems. In this study, we found that extraction of immunoglobulin G （IgG） from cow serum results in lower polystyrene NPs aggregation. Moreover, addition of isolated IgG or fibrinogen to fetal cow serum enhanced this aggregation, thus demonstrating that these factors are major drivers of NP aggregation in serum. Counter-intuitively, NP aggregation was inversely dependent on protein concentration; i.e., low protein concentrations induced large aggregates, whereas high protein concentrations induced small aggregates. Protein-induced NP aggregation and aggregate size were monitored by absorbance at 400 nm and dynamic light scattering, respectively. Here, we propose a mechanism behind the protein concentration dependent aggregation; this mechanism involves the effects of multiple protein interactions on the NP surface, surface area limitations, aggregation kinetics, and the influence of other serum proteins.

关键词： nanoparticles(NPs) protein coron aggregation immunoglobulin

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Hypothesized summative anal physiology score correlates but poorly predicts incontinence severity

引用

World journal of Gastroenterology 2017年第31期23卷 5732-5738页

作者： christopher j Young Assad Zahid Cherry E Koh jane M Young Department of Colorectal Surgery University of Sydney RPAH Medical Centre Discipline of Surgery University of Sydney Surgical Outcome Research Centre(SOu RCe) Royal Prince Alfred HospitalUniversity of Sydney School of Public health University of Sydney

To explore the relationship between such a construct and an existing continence score. METHODSA retrospective study of incontinent patients who underwent anal physiology (AP) was performed. AP results and Cleveland Clinic Continence Scores (CCCS) were extracted. An anal physiology score (APS) was developed using maximum resting pressures (MRP), anal canal length (ACL), internal and external sphincter defects and pudendal terminal motor latency. Univariate associations between each variable, APS and CCCS were assessed. Multiple regression analyses were performed. RESULTSOf 508 (419 women) patients, 311 had both APS and CCCS measured. Average MRP was 51 mmHg (SD 23.2 mmHg) for men and 39 mmHg (19.2 mmHg) for women. Functional ACL was 1.7 cm for men and 0.7 cm for women. Univariate analyses demonstrated significant associations between CCCS and MRP (P = 0.0002), ACL (P = 0.0006) and pudendal neuropathy (P le regression showed that the variables most useful in predicting CCCS were external sphincter defect, pudendal neuropathy and previous pelvic surgery, but only improving the scores predictive ability to 12.5%. CONCLUSIONThis study shows that the ability of AP tests to predict continence scores improves when considered collectively, but that a constructed summation model before and after multiple regression is poor at predicting the variability in continence scores.

关键词： Incontinence Anal physiology Anal canal Anal ultrasound Manometry Electromyography

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Impact of exome sequencing in inflammatory bowel disease

引用

World journal of Gastroenterology 2013年第40期19卷 6721-6729页

作者： christopher j.cardin.le judith R Kelsen Robert N Baldassano Hakon Hakonarson Center for Applied Genomics Children’s Hospital of PhiladelphiaAbramson Research Center Suite 1216PhiladelphiaPA 19104United States Division of Gastroenterology Hepatologyand NutritionDepartment of PediatricsChildren’s Hospital of PhiladelphiaPerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPA 19104United States

Approaches to understanding the genetic contribution to inflammatory bowel disease(IBD)have continuously evolved from family-and population-based epidemiology,to linkage analysis,and most recently,to genome-wide association studies(GWAS).The next stage in this evolution seems to be the sequencing of the exome,that is,the regions of the human genome which encode *** GWAS approach has been very fruitful in identifying at least 163 loci as being associated with IBD,and now,exome sequencing promises to take our genetic understanding to the next *** this review we will discuss the possible contributions that can be made by an exome sequencing approach both at the individual patient level to aid with disease diagnosis and future therapies,as well as in advancing knowledge of the pathogenesis of IBD.

关键词： Sequencing Exome Genetics Inflammatory bowel disease

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Zircon age depth-profiling sheds light on the early Caledonian evolution of the Seve Nappe Complex in west-central j?mtland

引用

Geoscience Frontiers 2022年第2期13卷 460-470页

作者： Katarzyna Walczak christopher j.Barnes jaroslaw Majka David G.Gee Iwona Klonowska AGH University of Science and Technology Faculty of GeologyGeophysics and Environmental Protectional.Mickiewicza 3030-059 KrakówPoland Uppsala University Department of Earth SciencesVillavagen 16752-36 UppsalaSweden

The Scandinavian Caledonides comprise nappe stacks of far-travelled allochthons that record closure of the Iapetus Ocean and subsequent continental collision of Baltica and *** Seve Nappe Complex(SNC)of the Scandinavian Caledonides includes relics of the outermost Baltoscandian passive margin that were subducted to mantle *** earliest of the deep subduction events has been dated to ca.500-480 *** of this event has been reported from the northern exposures of the *** south in the central and southern segments of the SNC,(ultra)high-pressure rocks have yielded younger ages in the range of ca.470-440 *** study provides the first record of the early Caledonian event in the southern *** evidence has been obtained by depth profiling of zircon grains that were extracted from the Tv?r?klumparna microdiamond-bearing *** zircon grains preserve eclogite facies overgrowths that crystallized at 482.6±3.8 Ma.A second,chemically-distinct zircon overgrowth records granulite facies metamorphism at 439.3±3.6 Ma,which corroborates previous geochronological evidence for granulite facies metamorphism at this *** on these results,we propose that the entire outer margin of Baltica was subducted in the late Cambrian to early Ordovician,but the record of this event may be almost entirely eradicated in the vast majority of lithologies by pervasive late Ordovician to early Silurian metamorphism.

关键词： Caledonian Orogeny Seve Nappe Complex Zircon geochronology Depth profiling HP/UHP metamorphism Double dunking

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Complications of button battery ingestion or insertion in children:a systematic review and pooled analysis of individual patient-level data

引用

World journal of Pediatrics 2024年第10期20卷 1017-1028页

作者： christopher Tran Carlos Nunez Guy D.Eslick Ruth Barker Elizabeth j.Elliott Sydney Medical School Faculty of Medicine and HealthThe University of SydneySydneyNSWAustralia The Australian Paediatric Surveillance Unit Level 2Kids ResearchThe Sydney Children’s Hospital Network(Westmead)Locked Bag 4001WestmeadNSW2145Australia Queensland Children’s Hospital BrisbaneQLDAustralia Queensland Injury Surveillance Unit Jamieson Trauma InstituteRoyal Brisbane and Women’s HospitalHerstonQLDAustralia

Background Button battery(BB)exposures are common in children and can have devastating *** reviewed current evidence on the complications associated with BB exposure and identified predictors of outcomes using individual patient-level *** sources We carried out a systematic review and pooled analysis by searching MEDLINE,Embase,and Scopus up to May 19,*** studies describe complications following BB exposures in children(agedle range(IQR)1.00–3.00]years and 399(90.9%)exposures were *** the 380 cases reporting sex,162(42.6%)were ***(192,48.1%)and respiratory difficulties(138,34.6%)were common presenting features for ingestions,while symptomatology was site-specific for *** complications included oesophageal mucosal damage alone(105,26.3%)and tracheooesophageal fistula(93,23.3%)for ingestions,and nasal septal perforation(22,55.0%)and mucosal damage alone(13,32.5%)for *** perforation occurred in 2.5%of ingestion cases,including perforation of Meckel's diverticulum,peritonitis,and jejunocolic *** complications were common among children who ***(≤2 years),battery exposure duration(>6 hours),and battery diameter(≥20 mm)were associated with common and severe complications of *** BB injuries are time-critical,with severe sequelae predominantly affecting young *** is *** work through regulation and safer battery design are required to eliminate this problem.

关键词： Child Electric power supplies Digestive systems Fatal outcome Foreign bodies

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Phalloplasty following penectomy for penile cancer

引用

Asian journal of Urology 2022年第4期9卷 460-466页

作者： Wai Gin lee A.Nim christopher David j.Ralph University College London Hospital LondonUnited Kingdom St Peter’s Andrology LondonUnited Kingdom

Objective:Penile reconstruction or phalloplasty following penectomy can be offered where the functional penile length is inadequate for a man to void while standing or to have sexual *** is usually staged due to the complex surgical techniques *** narrative review describes the technical concepts and summarises the contemporary outcomes following phalloplasty in this challenging ***:A retrospective review of the English literature was performed between january 1946 till November *** data were synthesised and complemented by the expert opinion of the authors with 20 years of experience in this *** flaps are ideally designed with an integrated urethra or alternatively,a further free flap urethroplasty can be ***-plasty is further complicated following penectomy by scarring from the previous surgery and the potential loss of structures that would normally be present at the recipient ***:There are limited published data with a total of 19 men recorded in the *** the radial artery forearm free flap and anterolateral thigh flap have been described in this cohort of *** outcomes including standing micturition,sensation in the neo-phallus,and the ability to orgasm are *** quality of life and satisfaction was also good despite the high risk for long-term complications of the neophallus and donor ***:Phalloplasty following penectomy requires microsurgical transfer of a free flap or a pedicled flap to reconstruct a *** erectile device is inserted at a later stage to facilitate sexual intercourse,if *** scarring from penectomy and the potential loss of vasculature that would normally be present at the recipient site may further complicate *** and functional outcomes are acceptable based on the limited published experience to date.

关键词： Humans Male Myocutaneous flap or transplantation Penis or surgery Phalloplasty Reconstructive surgical procedures Retrospective study Surgical flap Thigh or surgery Treatment outcome Urethra or surgery

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Analysis of coal pillar stability(ACPS): A new generation of pillar design software

引用

International journal of Mining Science and Technology 2019年第1期29卷 87-91页

作者： christopher Mark Zach Agioutantis Technical Support Mine Safety and Health Administration Department of Mining Engineering University of Kentucky

Thirty years ago, the analysis of longwall pillar stability(ALPS) inaugurated a new era in coal pillar *** was the first empirical pillar design technique to consider the abutment loads that arise from full extraction, and the first to be calibrated using an extensive database of longwall mining case *** was followed by the analysis of retreat mining stability(ARMPS) and the analysis of multiple seam stability(AMSS). These methods incorporated other innovations, including the coal mine roof rating(CMRR), the Mark-Bieniawski pillar strength formula, and the pressure arch loading model. They also built upon ever larger case history databases and employed more sophisticated statistical ***, these empirical methods are used in nearly every underground coal mine in the US. However,the piecemeal manner in which these methods have evolved resulted in some weaknesses. For example,in certain situations, it may not be obvious which program is the best to use. Other times the results from the different programs are not entirely consistent with each other. The programs have also not been updated for several years, and some changes were necessary to keep pace with new developments in mining practice. The analysis of coal pillar stability(ACPS) now integrates all three of the older software packages into a single pillar design framework. ACPS also incorporates the latest research findings in the field of pillar design, including an expanded multiple seam case history data base and a new method to evaluate room and pillar panels containing multiple rows of pillars left in place during pillar *** also includes updated guidance and warnings for users and features upgraded help files and graphics.

关键词： Pillar design Ground control Stability Empirical methods

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Identifying the dominant transport mechanism in single nanoscale pores and 3D nanoporous media

引用

Fundamental Research 2023年第3期3卷 409-421页

作者： Ying Yin Zhiguo Qu Masa Prodanovic christopher j.Landry MOE Key Laboratory of Thermo-Fluid Science and Engineering School of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an 710049China Hildebrand Department of Petroleum and Geosystems Engineering The University of Texas at AustinAustinTX 78712USA

Gas transport mechanisms can be categorized into viscous flow and mass diffusion,both of which may coexist in a porous media with multiscale pore *** determine the dominant transport mechanism and its contribution to gas transport capacity,the gas viscous flow and mass diffusion processes are analyzed in single nanoscale pores via a theoretical method,and are simulated in 3D nanoporous media via pore-scale lattice Boltzmann *** apparent permeability from the viscous flow and apparent diffusivity from the mass diffusion are estimated.A dimensionless parameter,i.e.,the diffusion-flow ratio,is proposed to evaluate the dominant transport mechanism,which is a function of the apparent permeability,apparent diffusivity,bulk dynamic viscosity,and working *** results show that the apparent permeability increases by approximately two orders of magnitude when the average Knudsen number(Kn_(avg))of the nanoporous media or Knudsen number(Kn)of single nanoscale pores increases from 0.1 to *** the same conditions,the increment in the apparent diffusivity is only approximately one order of *** Kn10,the apparent diffusivity has an upper bound(i.e.,Knudsen diffusivity).The dominant transport mechanism in single nanoscale pores is the viscous flow for 0.01less than *** nanoporous media,the dominant transport relies heavily on Kn_(avg) and the structural *** nanoporous media with the pore throat diameter of 3 nm,Kn_(avg)=0.2 is the critical point,above which the mass diffusion is dominant;otherwise,the viscous flow is *** Kn_(avg) increases to 3.4,the mass diffusion is overwhelming,with the maximum diffusion-flow ratio reaching ~4.

关键词： Porous media Viscous flow Mass diffusion Apparent permeability Apparent diffusivity Lattice Boltzmann method

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Predicting single-phase solid solutions in as-sputtered high entropy alloys:High-throughput screening with machine-learning model

引用

journal of Materials Science & Technology 2023年第7期138卷 70-79页

作者： ji-Chang Ren junjun Zhou christopher j.Butch Zhigang Ding Shuang Li Yonghao Zhao Wei Liu Nano and Heterogeneous Materials Center School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing 210094China Department of Biomedical Engineering Nanjing UniversityNanjing 210023China

Searching for single-phase solid solutions(SPSSs)in high-entropy alloys(HEAs)is a prerequisite for the intentional design and manipulation of microstructures of alloys in vast composition ***,to date,reported SPSS HEAs are still rare due to the lack of reliable guiding principles for the synthesis of new SPSS ***,we demonstrate an ensemble machine-learning method capable of discovering SPSS HEAs by directly predicting quinary phase diagrams based only on atomic composition.A total of 2198 experimental structure data are extracted from as-sputtered quinary HEAs in the literature and used to train a random forest classifier(termed AS-RF)utilizing bagging,achieving a prediction accuracy of 94.6%compared with experimental *** AS-RF model is then utilized to predict 224 quinary phase diagrams including∼32,000 SPSS HEAs in Cr-Co-Fe-Ni-Mn-Cu-Al composition *** extrapolation capability of the AS-RF model is then validated by performing first-principle calculations using density functional theory as a benchmark for the predicted phase transition of newly predicted ***,interpretation of the AS-RF model weighting of the input parameters also sheds light on the driving forces behind HEA formation in sputtered systems with the main contributors being:valance electron concentration,work function,atomic radius difference and elementary symmetries.

关键词： High entropy alloys Phase structures Machine learning Density functional theory

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：