检索结果-南通市图书馆

The Sediment and Hydrographic characteristics of Three Horseshoe crab Nursery Beaches in Hong Kong

Journal of Ocean University of Qingdao 2003年第1期2卷 35-43页

作者： helen m.c. chiu Brian morton Environmental Resources management (ERm)-Hong Kong Ltd Swire Institute of Marine Science and Department of Ecology and Biodiversity 979 King's Road Taikoo Place Island East Hong Kong University of Hong

Horseshoe crab juveniles have been recorded from sand and sandy-mud nursery beaches at Pak Nai (western New Territories), San Tau and Shui Hau (Lantau Island), Hong Kong. In order to provide a better understanding of these beaches and to identify those plausible factors which have made them preferred by spawning horseshoe crabs, environmental parameters, including temperature, salinity, pH and dissolved oxygen content of the water, and particle size distribution and organic matter content of the sediments at the three sites, were determined and compared. The hydrographic and sediment data obtained for the three study sites have revealed some common environmental features. The three nursery beaches are relatively remote, and far (in Hong Kong terms) from urbanized and densely populated areas. The beaches are generally well sheltered from strong wave action and inundated regularly by estuarine waters. Horseshoe crab adults tend to select these beaches for spawning as their protected features ensures the laid eggs are less likely to be washed out of the sand, and hatched juveniles can feed on the meiofauna and grow. Sediments of the three beaches largely comprise medium-sized sand particles and are moderately sorted, suggesting medium porosity and good water permeability. Such a sand type, with the generally high oxygen levels in incursing waters, may help create a well-oxygenated m.c.o-environment for the normal development of horseshoe crab eggs, larvae and juveniles. Lantau Island beaches at San Tau and Shui Hau are relatively free from organic pollution, as reflected in generally high dissolved oxygen level, and low BOD 5 and ammonia nitrogen values. Pak Nai is, however, more polluted.

关键词： sediment hydrography horseshoe crab nursery beaches Hong Kong

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

Relationship between left-behind status and cognitive function in older chinese adults: a prospective 3-year cohort study

引用

General Psychiatry 2023年第3期36卷 148-157页

作者： Hong-Guang Zhang Fang Fan Bao-Liang Zhong helen Fung-Kum.c.iu Department of Psychiatry Affiliated Wuhan Mental Health CenterTongji Medical College of Huazhong Universityof Science&TechnologyWuhanHubeiChina Department of Psychiatry Wuhan Mental Health CenterWuhanHubeiChina Department of clinical Psychology Wuhan Hospital for PsychotherapyWuhanHubeiChina Department of Psychiatry The Chinese University of Hong KongHong KongChina

Background Due to the inaccuracy of the traditional geographical distance-based definition of left-behind status,data on the negative effect of left-behind status on cognitive function among older adults are *** This study examined the cross-sectional and longitudinal associations of left-behind status with cognitive function in older chinese *** left-behind status definition was based on the frequency of face-to-face parent-child *** Data from a nationally representative sample of 8682 older adults(60+years)in 2015(5658 left behind and 3024 non-left behind),of which 6933 completed the follow-up in 2018,were obtained from the china Health and Retirement Longitudinal ***-behind older adults werebroadlydefined as those aged 60+years who had living adult children and saw their children less than once per *** cognitive function was assessed with a composite cognitive test with higher total scores indicating better cognitive *** Left-behind older adults had significantly lower cognitive test scores than non-left-behind older adults in both 2015(11.1(6.0)vs 13.2(5.9),t=15.863,pmographic factors,lifestyle factors,chronic medical conditions and the baseline cognitive test score(in the longitudinal analysis only),on average,the cognitive test score of left-behind older adults was 0.628 lower than their non-left-behind counterparts in 2015(t=5.689,pce in cognitive test scores attenuated to 0.322 but remained significant in 2018(t=2.733,p=0.006).conclusions Left-behind older chinese adults have a higher risk of poor cognitive function and cognitive decline than their non-left-behind *** efforts targeting left-behind older adults,such as encouraging adult children to visit their parents more regularly,are warranted to maintain or delay the progression of cognitive decline.

关键词： function cognitive maintain

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

Progress in neutron activation analysis for uranium

引用

Science china chemistry 1996年第2期39卷 219-224页

作者：杜鸿善李贵群董桂芝李俊兰 K.H.chiu c.m.Wai china Institute of Atom.c.Energy Beijing 102413 China Department of chemistry University of Idaho USA

A new type of extractant, sym-dibenzo-16-crown-5-oxyhydroxam.c.acid (HL) is introduced. The extractions of UO22+, Na+, K+, Sr2+, Ba2+ and Br- were studied with HL in chloroform. The results obtained show that UO22+ can be quantitatively extracted at pH values above 5, whereas the extractions of K+, Na+, Sr2+, Ba2+ and Br- are negligible in the pH range of 2 - 7. The dependence of the distribution ratio of U(VI) on both the concentration of the HL and pH are linear, and they have the same slope of 2. This suggests that U(VI) appears to form a 1:2 complex with ligand. Uranium(VI) can be selectively separated and concentrated from interfering elements such as Na, K, Sr and Br by solvent extraction with HL under specific conditions. The recovery of uranium is nearly 100% and the radionudear purity of uranium is greater than 99.99%. Therefore, neutron activation analysis has greatly improved the sensitivity and accuracy for the detection of trace uranium from seawater.

关键词： uranium preconcentration neutron activation analysis.

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

Biodegradable stent or balloon dilatation for benign oesophageal stricture: Pilot randomised controlled trial

引用

World Journal of Gastroenterology 2014年第48期20卷 18199-18206页

作者： Anjan Dhar helen close Yirupaiahgari K Viswanath colin J Rees helen c Hancock A Deepak Dwarakanath Rebecca H maier Douglas Wilson James m mason Department of Gastroenterology County Durhamand Darlington NHS Foundation Trust Co. Durham DL14 6ADUnited Kingdom Durham.c.inical Trials Unit School of Medicine Pharmacy and Health Durham University Queen’s Campus Wolfson Research Institute University Boulevard Stockton-on-Tees TS17 6BH United Kingdom Department of Surgery James Cook University Hospital Marton Road Middlesbrough TS4 3BW United Kingdom Department of Gastroenterology South Tyneside Hospitals NHS Foundation Trust Harton Lane South Shields NE34 0PL United Kingdom Department of Gastroenterology University Hospitals of North Tees Hardwick Stockton on Tees TS19 8PE United Kingdom

AIm: To undertake a randomised pilot study comparing biodegradable stents and endoscopic dilatation in patients with strictures.

关键词： Benign oesophageal stricture Biodegradable stent Endoscopic balloon dilatation Pilot study Randomised controlled trial Dysphagia

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

Dysregulation of RNA modification systems in clinical populations with neurocognitive disorders

引用

Neural Regeneration Research 2024年第6期19卷 1256-1261页

作者： helen m.Knight merve DemirbugenÖz Adriana PerezGrovas-Saltijeral Division of cells Organisms and Molecular GeneticsSchool of Life SciencesUniversity of NottinghamNottinghamUK Department of Pharm.c.utical Toxicology Faculty of PharmacyAnkara UniversityAnkaraTurkey

The study of modified RNA known as epitranscriptom.c. has become increasingly relevant in our understanding of disease-modifying *** of N6 adenosine(m^(6)A)and c5 cytosine(m^(5)c)bases occur on mRNAs,tRNA,mt-tRNA,and rRNA species as well as non-coding *** emerging knowledge of RNA binding proteins that act as writer,reader,and eraser effector proteins,comes a new understanding of physiological processes controlled by these *** processes when spatiotemporally disrupted within cellular nanodomains in highly specialized tissues such as the brain,give rise to different forms of *** this review,we discuss accumulating evidence that changes in the m^(6)A and m^(5)c methylation systems contribute to neurocognitive *** studies first identified mutations within FmR1 to cause intellectual disability Fragile X syndromes several years before FmR1 was identified as an m^(6)A RNA reader ***,familial mutations within the m^(6)A writer gene mETTL5,m^(5)c writer genes NSUN2,NSUN3,NSUN5,and NSUN6,as well as THOc2 and THOc6 that form a protein complex with the m^(5)c reader protein ALYREF,were recognized to cause intellectual development ***,differences in expression of the m^(5)c writer and reader effector proteins,NSUN6,NSUN7,and ALYREF in brain tissue are indicated in individuals with Alzheimer's disease,individuals with a high neuropathological load or have suffered traumatic brain ***,an abundance of m^(6)A reader and anti-reader proteins are reported to change across brain regions in Lewy bodies diseases,Alzheimer's disease,and individuals with high cognitive reserve.m^(6)A-modified RNAs are also reported significantly more abundant in dementia with Lewy bodies brain tissue but significantly reduced in Parkinson's disease tissue,whilst modified RNAs are misplaced within diseased cells,particularly where synapses are *** parahippocampal brain tissue,m^(6)A modification is enri

关键词： 5-methylcytosine methylation Alzheimer's disease cognitive diseases epitranscriptom.c. intellectual disability Lewy body diseases N6 adenosine RNA modification

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

Short-term effect of physical activity on sleep health:A population-based study using accelerometry

引用

Journal of Sport and Health Science 2022年第5期11卷 630-638页

作者： Andrea Wendt Inácio crochemore m.da Silva helen Goncalves Ana menezes Fernando Barros Fernando c.Wehrmeister Post-graduate Program in Epidemiology Federal University of PelotasPelotas 96020-220Brazil

Background:Regular physical activity(PA) is an important behavior in improving sleep ***,the short-term effects of PA on sleep are still *** study aimed to verify the effect of different intensities of PA practiced in different periods of the day on the subsequent sleep night in a population-based cohort of young ***::Prospective analyses were conducted for PA performed during the day and its effect on the following sleep night using data from the22-year follow-up of the 1993 Pelotas Birth cohort in Brazil(mean age of participants-22.6 years).Wrist-worn accelerometry was usedto measure both PA and sleep *** intensity,we analyzed the sleep effect of light PA(LPA),moderate PA,and vigorous PA,stratified by *** variables were sleep time window(STW;the difference between sleep onset and sleep end),total sleep time(TST;the sum of minutes classified as sleep in STW),and sleep percent(SP;SP=(TST/STW);expressed in percentage).We performed generalized estimating equations using Stata ***::The means of STW,TST,and SP were 443.6 min/day,371.1 min/day,and 84%,*** spent in moderate PA and vigorous PA in the morning and afternoon was not associated with sleep *** men,10 min/day of morning LPA increased TST by2.56 min/*** women,10 min/day of morning LPA increased SP by 0.15 percentage *** LPA also increased SP by 0.09 percentage points for *** PA seems to have an inverse effect on sleep variables for any intensity and both ***::The effect of PA on sleep health is intrinsically related to the period of the day in which it is *** effect magnitude is different between *** better sleep health,it is preferable that PA be performed during the day.

关键词： Accelerometer Exercise Physical activity Population-based study Sleep health

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

Neuropathic pain-like symptoms and pre-surgery radiographic severity contribute to patient satisfaction 4.8 years post-total joint replacement

引用

World Journal of Orthopedics 2017年第10期8卷 761-769页

作者： Sophie c Warner helen Richardson Wendy Jenkins Thomas Kurien m.c.ael Doherty Ana m Valdes Academ.c.Rheumatology University of NottinghamClinical Sciences BuildingNottingham City Hospital Department of cardiovascular Sciences University of Leicester and National Institute for Health Res-earchLeicester Cardiovascular Biomedical Research Unit Arthritis Research UK Pain centre Academ.c.Division of Trauma and Orthopaedics Queens Medical Centre

AIm To investigate a comprehensive range of factors that contribute to long-term patient satisfaction post-total joint replacement(TJR) in people who had undergone knee or hip replacement for *** Participants(n = 1151) were recruited from Nottinghamshire post-total hip or knee replacement. Questionnaire assessment included medication use, the pain-DETEcT questionnaire(PDQ) to assess neuropathic pain-like symptoms(NP) and TJR satisfaction measured on average 4.8 years post-TJR. Individual factors were tested for an association with post-TJR satisfaction, before incorporating all factors into a full model. Data reduction was carried out using LASSO and receiveroperator characteristic(ROc) curve analysis was used to quantify the contribution of variables to post-TJR *** After data reduction, the best fitting model for post-TJR satisfaction included various measures of pain, history of revision surgery, smoking, pre-surgical X-ray severity, WOm.c.function scores and various comorbidities. ROc analysis of this model gave AUc = 0.83(95%cI: 0.80-0.85). PDQ scores were found to capture m.c. of the variation in post-TJR satisfaction outcomes: AUc = 0.79(0.75-0.82). Pre-surgical radiographic severity was associated with higher post-TJR satisfaction: OR_(satisfied) = 2.06(95%cI: 1.15-3.69), P = *** These results highlight the importance of pre-surgical radiographic severity, post-TJR function, analgesic medication use and NP in terms of post-TJR satisfaction. The PDQ appears to be a useful tool in capturing factors that contribute to post-TJR satisfaction.

关键词： Osteoarthritis Patient satisfaction Total joint arthroplasty Neuropathic pain Surgery outcomes

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

Three New cucurbitacins from Hemsleya lijiangensis

引用

chinese chem.c.l Letters 2003年第4期14卷 389-392页

作者： ming Hua chiu Juan GAO State Key Laboratory of Phytochemistry and Plant Resource in West china Kunming Institute of BotanyChinese Academy of SciencesKunming 650204

Three new cucurbitacins were isolated from the BuOH extract of the rhizomes of Hemsleya lijiangensis. Their structures were elucidated as 23, 24 -dihydro cucurbitacin F-16, 25-diacetate(1), 23, 24-dihydro cucurbitacin F-16, 25-diacetate-2-O-β-D glucopyranoside (2), 23, 24-dihydro-cucurbitacin F-16-acetate(3), respectively; by spectral analyses.

关键词： Hemsleya lijiangensis cucurbitaceae Hemslecins D, E, F.

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

Unsupervised learning on scientific ocean drilling datasets from the South china Sea

引用

Frontiers of Earth Science 2019年第1期13卷 180-190页

作者： Kevin c.TSE Hon-chim.c.IU man-Yin TSANG Yiliang LI Edmund Y.LAm Department of Earth Sciences The University of Hong KongPokfulamHong KongChina Department of Geography and centre for Geo-computation Studies Hong Kong Baptist UniversityKowloon TongHong KongChina Department of Earth Sciences University of TorontoTorontoON M5S 2M8Canada Department of Electrical and Electronic Engineering The University of Hong KongPokfulamHong KongChina

Unsupervised learning methods were applied to explore data patterns in multivariate geophysical datasets collected from ocean floor sediment core samples coming from scientific ocean drilling in the South china *** to studies on similar datasets,but using supervised learning methods which are designed to make predictions based on sample training data,unsupervised learning methods require no a priori information and focus only on the input *** this study,popular unsupervised learning methods including K-means,self-organizing maps,hierarchical clustering and random forest were coupled with different distance metrics to form exploratory data *** resulting data clusters were externally validated with lithologic units and geologic time scales assigned to the datasets by conventional methods. compact and connected data clusters displayed varying degrees of correspondence with existing classification by lithologic units and geologic time scales.K-means and self-organizing maps were observed to perform better with lithologic units while random forest corresponded best with geologic time *** study sets a pioneering example of how unsupervised m.c.ine learning methods can be used as an automatic processing tool for the increasingly high volume of scientific ocean drilling data.

关键词： m.c.ine learning unsupervised learning ODP IODP clustering

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

Record of Early Tonian mafic magmatism in the central Espinhaco(Brazil):New insights for break-up of the Neoproterozoic landmass ancestor of Sao Francisco-congo paleocontinent

引用

Geoscience Frontiers 2020年第6期11卷 2323-2337页

作者： helen F.moreira AndréDanderfer Alice F.O.costa Samuel m.Bersan cristiano c.Lana Gláucia N.Queiroga Post Graduate Program of Department of Geology Mine SchoolFederal University of Ouro PretoBrazil Department of Geology Mine SchoolFederal University of Ouro PretoBrazil

Petrological characterization,U-Pb geochronology,Lu-Hf analyses and major and trace element data from mafic intrusions in the central Espinhaco(central portion of the Brazilian shield)are used here to investigate the geological significance of the Early Neoproterozoic magmatism in the context of the Sao Francisco-congo *** mafic bodies are represented by medium to coarse-grained metagabbros with plagioclase,amphibole and *** U-Pb isotopic data from two samples yielded weighted mean 206pb/238U ages of 895±3.4 ma(mSWD=1.7)and 896±2.4 ma(mSWD=0.64),regarded as the best estimates for the crystallization age of these mafic *** and trace element data(including REEs)show that the gabbros originated from a subalkaline tholeiitic magma,typical of intraplate *** rocks are slightly enriched in LREEs and LILEs and depleted in *** new isotope and geochem.c.l data,along with regional knowledge,indicate that these metagabbros mark the beginning of an important Tonian-age extensional tectonic event of the landmass of which the Sao Francisco-congo paleocontinent was part(Rodinia supercontinent or central African block?).We furthermore suggest that these rocks belong to a prominent suite of Tonian-age mafic rocks that mark a diachronic breakup attempt of this landmass which may have occurred from south to north along the Espinhaco mountain range.

关键词： mafic rocks Espinhaco basin Sao Francisco-congo paleocontinent Tonian rifting U–Pb 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

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：