检索结果-南通市图书馆

The functional significance of dentin sialoprotein-phosphophoryn and dentin sialoprotein

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Oral Science 2018年第4期10卷 197-202页

作者： helena Ritchie Department of Cariology Restorative Sciences and EndodonticsUniversity of Michigan School of Dentistry

Phosphophoryn (PP) and dentin sialoprotein (DSP) are the most dominant non-collagenous proteins in dentin. PP is an extremely acidic protein that can function as a mineral nucleator for dentin mineralization. DSP was first identified in 1981, yet its functional significance is still controversial. Historically, these two proteins were considered to be independently synthesized and secreted by dental pulp cells into the developing dentin matrix. However, with the identification of the DSP coding sequence in 1994, followed2 years later by the finding that the PP coding sequence was located immediately downstream from the DSP sequence, it became immediately clear that DSP and PP proteins were derived from a single DSP-PP (i.e., dentin sialophosphoprotein, DSPP) *** DSPP cDNA became available, tremendous progress has been made in studying DSP-PP mRNA distribution and DSP generation from the DSP-PP precursor protein at specific cleavage sites by protease tolloid-related-1 (TLR1) or bone morphogenetic protein 1 (BMP1). The functions of DSP-PP and DSP were investigated via DSP-PP knockout (KO) and DSP knockin in DSP-PP KO mice. In addition, a number of in vitro studies aimed to elucidate DSPP and DSP function in dental pulp cells.

关键词： DSP The functional significance of dentin sialoprotein-phosphophoryn and dentin sialoprotein

effect of ceria surface facet on stability and reactivity of isolated platinum atoms

在线全文

学校读者我要写书评

暂无评论

Nano Research 2022年第7期15卷 5922-5932页

作者： Bochuan Song Shuxin Si Asiye Soleymani Yan Xin helena e.Hagelin-Weaver Department of Chemical engineering University of FloridaGainesville 32611USA National High Magnetic Field Laboratory Florida State UniversityTallahassee 32310USA

Well-defined surface structures and uniformity are key factors in exploring structure–activity relationships in heterogeneous catalysts.A modified atomic layer deposition method and three well-defined CeO_(2) nanoshapes,octahedra with(111)surfaces,cubes exposing(100)facets,and rods with(100)and(110)surface facet terminations,were utilized to synthesize ultra-low loading Pt/CeO_(2) catalysts and allow investigations on the influence of ceria surface facet on isolated Pt species under reducing conditions.A mild reduction temperature(150℃)reduces the initial platinum ions present on the surfaces of the ceria support but preserves the isolated Pt atoms on all ceria surface *** contrast,a reduction temperature of 350°C,reveals very different interactions between the initial single Pt atoms and the various ceria surface facets,leading to dissimilar and nonuniform Pt ensembles on the three ceria *** isolate facet dependent Pt–CeO_(2) interactions and avoid variations between Pt species,the Pt1/CeO_(2) catalysts after reduction at 150°C were subjected to CO oxidation *** isolated Pt atoms on the CeO_(2) octahedra and cubes are less active in the CO oxidation reaction,compared with Pt on CeO_(2) *** the case of Pt on the CeO_(2) octahedra this is due to strongly bound CO blocking active sites together with a stable CeO_(2)(111)surface limiting the oxygen supply from the *** the CeO_(2) cubes,some Pt is not available for reaction and CO is bound strongly on the available Pt *** addition,the Pt catalysts supported on the CeO_(2) cubes are not stable with time on *** isolated Pt atoms on the CeO_(2) rods are considerably more active under these conditions and this is due to a weaker Pt–CO bond strength and more facile reverse oxygen spillover from the defect-rich(110)surfaces of the rods due to the lower energy of oxygen vacancy formation on this CeO_(2) *** Pt supported on the CeO_(2) rods is also remarkably stable with t

关键词： single atom catalyst CeO_(2)shapes facet effects Pt1/CeO_(2) diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)

Finland is following the trend--sperm quality in Finnish men

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2013年第2期15卷 162-164,I0004页

作者： helena e Virtanen Sergey Sadov Matti Vierula Jorma Toppari Departments of Physiology and Paediatrics University of Turku Turku FI-20520 Finland

Finnish men have had a reputation for good semen quality. This was based on semen studies comparing Finnish men with other europeans. However, those studies also showed that sperm concentrations of young men from the general population were only two-thirds of those of fertile men. Longitudinal follow-up of semen quality in young Finnish men showed a sig- nificant decline during 1998-2006, suggesting that Finland is following the global trend of impaired male reproductive health.

关键词：

Physiology of gangliosides and the role of antiganglioside antibodies in human diseases

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Cellular & Molecular Immunology 2020年第4期17卷 313-322页

作者： Gianni Cutillo Anna-helena Saariaho Seppo Meri Translational Immunology Research Program and the Department of Bacteriology and Immunology University of HelsinkiHelsinkiFinland Humanitas University MilanRozzanoItaly Helsinki University Hospital Laboratory(HUSLAB) HelsinkiFinland

Gangliosides are structurally and functionally polymorphic sialic acid containing glycosphingolipids that are widely distributed in the human *** play important roles in protecting us against immune attacks,yet they can become targets for autoimmunity and act as receptors for microbes,like the influenza viruses,and toxins,such as the cholera *** expression patterns of gangliosides vary in different tissues,during different life periods,as well as in different *** against gangliosides(AGA)can target immune attack e.g.,against neuronal cells and neutralize their complement inhibitory *** are important especially in acquired demyelinating immune-mediated neuropathies,like Guillain–Barrésyndrome(GBS)and its variant,the Miller–Fisher syndrome(MFS).They can emerge in response to different microbial agents and immunological ***,they can be involved in a variety of *** addition,antibodies against GM3 were found in the sera of patients vaccinated with Pandemrix®,who developed secondary narcolepsy,strongly supporting the autoimmune etiology of the disease.

关键词： ganglioside Guillain-Barre syndrome complement narcolepsy sialic acid

Concordance of the point-of-care circulating cathodic antigen test for the diagnosis of intestinal schistosomiasis in a low endemicity area

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Infectious Diseases of Poverty 2019年第3期8卷 99-100页

作者： Sergei Rodrigo magalhaes de Sousa Isabelle helena Lima Dias Alvaro Luan Santana Fonseca Bianca Rodrigues Contente Joyce Favacho Cardoso Nogueira Tatyellen Natasha da Costa Oliveira Stefan Michael Geiger Martin Johannes enk Programa de Pos-Graduacao Strictu Sensu em Biologia Parasitaria na Amazonia da Universidade do estado do Para Tv.Perebebui2623-MarcoBelemPA 66087Brazil Laboratorio de Parasitoses Intestinais Esquistossomose e Malacologia(LPIEM)Secgao de ParasitologiaInstituto Evandro Chagas/SVS/MSAnanindeuaParaBrazil

Background:The Kato-Katz technique is recommended worldwide for the diagnosis of intestinal schistosomiasis,detecting parasite eggs in feces of infected ***,new tests have been developed in order to facilitate diagnosis,*** detection of specific antigens secreted by schistosomes,such as the circulating cathodic antigen(CCA).The aim of this study was to evaluate the performance of the point-of-care circulating cathodic antigen test(POC-CCA)compared to the Kato-Katz technique in a low prevalence area in the Amazon Region,located in the municipality of Primavera,State of Para,***:Positivity rates of the POC-CCA test and the Kato-Katz technique were *** sensitivity,specificity,accuracy and kappa coefficient were determined by comparing both *** reference standard was established using 16 Kato-Katz slides,12 of the first fecal sample,two of the second and two of the third *** study also included the concordance between POC-CCA results and different numbers and combinations of Kato-Katz ***:The prevalence of schistosomiasis according to the reference standard or POC-CCA test reached a rate of 9.4%or 23.9%,respectively,among a total of 372 *** positivity rates by the Kato-Katz technique increased from 2.4 to 9.4%,according to the increase in the number of slides examined and fecal samples colleaed.A sensitivity of 55.6%,specificity 76.9%,accuracy 76%and k coefficient of 0.06 was observed by comparing one slide of the first sample and *** 6 slides from three different samples,two slides of each,with POC-CCA resulted in a sensitivity of 583%,specificity 78.4%,accuracy 77%and k coefficient of ***,the comparison of 16 slides from three different samples with POC-CCA revealed a sensitivity of 65.7%,specificity 80.4%,accuracy 79%,and k coefficient of ***:The immunochromatographic test has the potential to be an important tool to combat schistosomiasis because of its practi

关键词： Schistosoma mansoni Kato-Katz POC-CCA Accuracy Diagnosis Low prevalence area

Urban Park Soil and Vegetation: effects of Natural and Anthropogenic Factors

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pedosphere 2015年第3期25卷 392-404页

作者： Pariente SARAH helena Michaela ZHeVeLeV Atar OZ Laboratory of Geomorphology and Soil Department of Geography and EnvironmentBar-Ilan University

Various soil surface components, such as trees, shrubs and biological crusts, and human recreational activities, e.g., barbecues and trampling by visitors, may divide the area of the urban park into smaller fragments/mieroenvironments, differentiated by their microenvironmental conditions, which may differ in soil and vegetation characteristics. The spatial changes in the soil and vegetation characteristics and their causes were investigated in an urban park located south of Tel Aviv-Jaffa, Israel. The area of the park is 0.5 km^2, including groves, a lake, lawns, and rest areas. Soil was sampled in nine microenvironments, of which seven were within the park： under Ceratonia siliqua trees （CsU）, under Ficus sycomorus trees （FLU）, rest area between tables under F. sycomorus （FIB）, rest area under tables under F. sycomorus （FIT）, open area with bare soil （OaS）, open area with biological crust cover （OaC）, and open area covered by herbaceous vegetation （OaV）. Two more microenvironments, planar and sloping open areas （CoP and CoS, respectively） in the vicinity of the park, were used as the controls. electrical conductivity, concentrations of soluble ions （Mg^2＋, Ca^2＋, Na^＋, K^＋ and HCO3）, pH, contents of organic carbon, calcium carbonate and moisture, and grain size distribution were determined. In addition, herbaceous vegetation cover, number and diversity of herbaceous vegetation species were measured. It was found that soil properties and herbaceous vegetation characteristics varied within the park. Soil organic carbon, electrical conductivity, soluble salts, penetration depth, and vegetation characteristics were affected by human activities, mainly in the rest area between the tables. In contrast, the above characteristics were affected by natural factors mainly in the rest of the microenvironments, which were subjected to low levels of anthropogenic intervention. The heterogeneous structure of the park, as represented by the various microenvironments, offered new

关键词： anthropogenic activity herbaceous vegetation microenvironment soil properties species diversity

Ultraviolet light exposure and its penetrance through the eye in a porcine model

在线全文

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(english edition) 2023年第2期16卷 172-177页

作者： Hideki Fukuoka helena e.Gali Jennifer J.Bu Ruti Sella Natalie A.Afshari Shiley eye Institute Viterbi Family Department of OphthalmologyUniversity of California San DiegoLa JollaCA 92093USA

AIM:To determine the amount of ultraviolet(UV)light irradiance that various layers of the eye receive as sunlight passes through the eye,and to investigate the protective benefits of UV light-blocking contact ***:Twenty-four porcine eyes were prepared in one of three ways:isolated cornea,cornea and lens together,or whole eye *** light irradiance was measured with a UV-A/B light meter before and after the eye preparations were placed over the meter to measure UV light penetration in each eye *** the whole eye preparation,a hole was placed in the fovea to measure light as it passed through the ***,UVprotective contact lenses were placed over the structures,and UV light penetrance was *** of UV light exposure were taken outdoors at various locations and ***:Cornea absorbed 63.56%of UV light that reached the *** and lens absorbed 99.34%of UV *** eye absorbed 99.77%of UV *** UV-protective contact lenses were placed,absorption was 98.90%,99.55%,and 99.87%,*** light exposure was dependent on directionality and time of day,and was greatest in areas of high albedo that reflect significant amounts of light,such as a ***:Cornea absorbs the majority of UV light that reaches the eye in this ***-protective contact lenses reduce UV exposure to the *** with high albedo expose the eye to higher levels of UV light.

关键词： ultraviolet light penetrance contact lens cornea lens

Siderophore-Producing Rhizobacteria as a Promising Tool for empowering Plants to Cope with Iron Limitation in Saline Soils:A Review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pedosphere 2019年第4期29卷 409-420页

作者： Maria J.FeRReIRA helena SILVA Angela CUNHA Biology Department and Centre for environmental and Marine Studies(CeSAM) University of Aveiro Campus de Santigo

Iron(Fe) bioavailability to plants is reduced in saline soils;however, the exact mechanisms underlying this effect are not yet completely understood. Siderophore-expressing rhizobacteria may represent a promising alternative to chemical fertilizers by simultaneously tackling salt-stress effects and Fe limitation in saline soils. In addition to draught, plants growing in arid soils face two other major challenges: high salinity and Fe deficiency. Salinity attenuates growth, affects plant physiology, and causes nutrient imbalance,which is, in fact, one of the major consequences of saline stress. Iron is a micronutrient essential for plant development, and it is required by several metalloenzymes involved in photosynthesis and respiration. Iron deficiency is associated with chlorosis and low crop productivity. The role of microbial siderophores in Fe supply to plants and the effect of plant growth-promoting rhizobacteria(PGPR) on the mitigation of saline stress in crop culture are well documented. However, the dual effect of siderophore-producing PGPR, both on salt stress and Fe limitation, is still poorly explored. This review provides a critical overview of the combined effects of Fe limitation and soil salinization as challenges to modern agriculture and intends to summarize some indirect evidence that argues in favour of siderophore-producing PGPR as biofertilization agents in salinized soils. Recent developments and future perspectives on the use of PGPR are discussed as clues to sustainable agricultural practices in the context of present and future climate change scenarios.

关键词： aridity bioavailability biofertilizer Fe deficiency high salinity plant growth-promoting rhizobacteria(PGPR) saline stress soil salinization

Glutamine and glutamate supplementation raise milk glutamine concentrations in lactating gilts

在线全文

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2012年第1期3卷 25-31页

作者： helena emilia CCC Manso Helio C Manso Filho Luiz e de Carvalho Marianne Kutschenko eduardo T Nogueira Malcolm Watford Department of Animal Sciences Rural Federal University of PernambucoRecifePE52171-900Brazil Departament of Animal Sciences Federal University of CearáFortalezaCE60020-181Brazil Ajinomoto do Brazil S oPauloSP04015-001Brazil Department of Nutritional Sciences Rutgers UniversityNew BrunswickNJ08901USA.

Glutamine is the most abundant amino acid in milk, and lactation is associated with increased glutamine utilization both for milk synthesis and as a fuel for the enlarged small intestine. A number of recent studies have indicated that lactation is accompanied by a mild catabolic state in which skeletal muscle proteins are degraded to provide amino acids that are used to synthesize additional glutamine. In this study we tested the hypothesis that supplemental L-glutamine or the commercially available glutamine supplement Aminogut （2.5% by weight mixed into daily feed） provided to gilts from 30 days prior to parturition until 21 days post-parturition would prevent a decrease in skeletal muscle glutamine while increasing the glutamine content of the milk. Muscle glutamine content decreased （P 〈 0.05） in control animals during lactation but this was prevented by supplementation with either L-glutamine or Aminogut. In this study, neither lactation nor supplementation had any effect on plasma glutamine or glutamate content. Free glutamine, and the total glutamine plus glutamate concentrations in milk from the control and the Aminogut group rose （P 〈 0.05） during the first 7 days of lactation, with milk concentrations in the L-glutamine supplemented group showing a similar trend （P = 0.053）. Milk glutamate remained constant between day 7 and 21 of lactation in the control and L-glutamine supplemented groups, but by day 21 of lactation the free glutamine, glutamate, and glutamine plus glutamate concentrations in milk from Aminogut-treated gilts were higher than those of control gilts. Thus dietary glutamine supplementation can alleviate the fall in intramuscular glutamine content during lactation in gilts, and may alleviate some of the catabolic effects of lactation. Furthermore, the increased milk glutamine content in the supplemented gilts may provide optimum nutrition for piglet development.

关键词： glutamate glutamine lactation milk pig skeletal muscle