全文获取类型
收费全文 | 209篇 |
免费 | 14篇 |
出版年
2022年 | 4篇 |
2021年 | 8篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 5篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 12篇 |
2014年 | 12篇 |
2013年 | 18篇 |
2012年 | 15篇 |
2011年 | 15篇 |
2010年 | 14篇 |
2009年 | 8篇 |
2008年 | 9篇 |
2007年 | 11篇 |
2006年 | 12篇 |
2005年 | 9篇 |
2004年 | 12篇 |
2003年 | 5篇 |
2002年 | 8篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有223条查询结果,搜索用时 15 毫秒
61.
Tetsu Ando Mizue Koike Masaaki Uchiyama Hiroshi Kuroko 《Bioscience, biotechnology, and biochemistry》2013,77(10):2691-2694
Each of fifty-one conjugated dienes (alcohols, acetates and aldehydes) with a C12, C14 or C16 straight chain was applied to a rubber cap in a sticky-type trap as a single-component lure. Some diene compounds were mixed with their functional derivatives or structurally related monoenes to make two-component lures. In field trials conducted from 1984 to 1986, the new attraction of male moths of nineteen species was observed. These species were classified into nine families as follow: Gracillariidae, Yponomeutidae, Oecophoridae, Cosmopterigidae, Tortricidae (Olethreuti- nae and Tortricinae), Pyralidae, Pterophoridae, Drepanidae and Geometridae. This result indicates that the conjugated dienes are one of the main groups of lepidopterous sex pheromones. Some interesting information concerned with the taxonomy of the attracted moths and with the characteristics of the chemical structures of their attractants was obtained. 相似文献
62.
Mahipal A Terai M Berd D Chervoneva I Patel K Mastrangelo MJ Sato T 《Cancer immunology, immunotherapy : CII》2011,60(7):1039-1045
Objectives
Interleukin-10 (IL-10) downregulates T-cell-mediated immune responses. We studied the association between IL-10 production by freshly isolated melanoma cell suspensions in vitro and overall survival in patients undergoing adjuvant treatment with a vaccine prepared from the same autologous melanoma cells modified with a hapten, dinitrophenyl (DNP). 相似文献63.
Yanagi K Ashizaki M Yagi H Sakurai K Lee YH Goto Y 《The Journal of biological chemistry》2011,286(27):23959-23966
Although amyloid fibrils deposit with various proteins, the comprehensive mechanism by which they form remains unclear. We studied the formation of fibrils of human islet amyloid polypeptide associated with type II diabetes in the presence of various concentrations of 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) under acidic and neutral pH conditions using CD, amyloid-specific thioflavin T fluorescence, fluorescence imaging with thioflavin T, and atomic force microscopy. At low pH, the formation of fibrils was promoted by HFIP with an optimum at 5% (v/v). At neutral pH in the absence of HFIP, significant amounts of amorphous aggregates formed in addition to the fibrils. The addition of HFIP suppressed the formation of amorphous aggregates, leading to a predominance of fibrils with an optimum effect at 25% (v/v). Under both conditions, higher concentrations of HFIP dissolved the fibrils and stabilized the α-helical structure. The results indicate that fibrils and amorphous aggregates are different types of precipitates formed by exclusion from water-HFIP mixtures. The exclusion occurs through the combined effects of hydrophobic interactions and electrostatic interactions, both of which are strengthened by low concentrations of HFIP, and a subtle balance between the two types of interactions determines whether the fibrils or amorphous aggregates dominate. We suggest a general view of how the structure of precipitates varies dramatically from single crystals to amyloid fibrils and amorphous aggregates. 相似文献
64.
Resumen La presente revisión tuvo como objetivo la resolución del complejoBauhinia macranthera. Por medio de un estudio de morfología comparada que incluyó polen, se reconocen aBauhinia bartlettii, B. macranthera yB. ramosissima; se restableceB. retifolia y se propone aB. ramosissima var. uniflora, como nueva combinación.
The purpose of this study was the resolution of theBauhinia macranthera complex using comparative morphology, including pollen.Bauhinia bartlettii, B. macranthera B. ramosissima, andB. retifolia are recognized, andB. ramosissima var. uniflora is proposed as a new combination.
相似文献
65.
Izuki Endo Miwa Kobatake Natsuko Tanikawa Tatsuro Nakaji Mizue Ohashi Naoki Makita 《Annals of botany》2021,128(1):59
Background and AimsCondensed tannin (CT) is an important compound in plant biological structural defence and for tolerance of herbivory and environmental stress. However, little is known of the role and location of CT within the fine roots of woody plants. To understand the role of CT in fine roots across diverse species of woody dicot, we evaluated the localization of CT that accumulated in root tissue, and examined its relationships with the stele and cortex tissue in cross-sections of roots in 20 tree species forming different microbial symbiotic groups (ectomycorrhiza and arbuscular mycorrhiza).MethodsIn a cool-temperate forest in Japan, cross-sections of sampled roots in different branching order classes, namely, first order, second to third order, fourth order, and higher than fourth order (higher order), were measured in terms of the length-based ratios of stele diameter and cortex thickness to root diameter. All root samples were then stained with ρ-dimethylaminocinnamaldehyde solution and we determined the ratio of localized CT accumulation area to the root cross-section area (CT ratio).Key ResultsStele ratio tended to increase with increasing root order, whereas cortex ratio either remained unchanged or decreased with increasing order in all species. The CT ratio was significantly positively correlated to the stele ratio and negatively correlated to the cortex ratio in second- to fourth-order roots across species during the shift from primary to secondary root growth. Ectomycorrhiza-associated species mostly had a higher stele ratio and lower cortex ratio than arbuscular mycorrhiza-associated species across root orders. Compared with arbuscular mycorrhiza species, there was greater accumulation of CT in response to changes in the root order of ectomycorrhiza species.ConclusionsDifferent development patterns of the stele, cortex and CT accumulation along the transition from root tip to secondary roots could be distinguished between different mycorrhizal associations. The CT in tissues in different mycorrhizal associations could help with root protection in specific branching orders during shifts in stele and cortex development before and during cork layer formation. 相似文献
66.
Michael Chu Harini Sampath David Y. Cahana Christoph A. Kahl Romel Somwar Anda Cornea Charles T. Roberts Jr. Oleg Varlamov 《Molecular biology of the cell》2014,25(25):4096-4105
The spatiotemporal dynamics of triglyceride (TG) storage in unilocular adipocytes are not well understood. Here we applied ex vivo technology to study trafficking and metabolism of fluorescent fatty acids in adipose tissue explants. Live imaging revealed multiple cytoplasmic nodules surrounding the large central lipid droplet (cLD) of unilocular adipocytes. Each cytoplasmic nodule harbors a series of closely associated cellular organelles, including micro–lipid droplets (mLDs), mitochondria, and the endoplasmic reticulum. Exogenously added free fatty acids are rapidly adsorbed by mLDs and concurrently get esterified to TG. This process is greatly accelerated by insulin. mLDs transfer their content to the cLD, serving as intermediates that mediate packaging of newly synthesized TG in the large interior of a unilocular adipocyte. This study reveals novel cell biological features that may contribute to the mechanism of adipocyte hypertrophy. 相似文献
67.
The termite soldier is unique because of its defensive task in a colony. In Nasutitermitinae (family Termitidae), soldiers use in their defense frontal glands, which contain various chemical substances. To isolate the gene products related to the chemical defense, we compared the sodium dodecyl sulfate-polyacrylamide gel electrophoresis protein profiles of soldier heads with those of workers of the nasute termite Nasutitermes takasagoensis. We identified a 26-kDa soldier-specific protein (Ntsp1) that exists most abundantly in the dorsal head including the frontal gland. We determined the N-terminal amino acid sequence of Ntsp1, and then cloned the Ntsp1 cDNA by rapid amplification of the cDNA ends-polymerase chain reaction (RACE-PCR). A putative signal peptide was detected upstream of the N-terminus and the Ntsp1 protein showed sequence homologies with known insect secretory carrier proteins, which bind to hydrophobic ligands such as juvenile hormone, suggesting that Ntsp1 belongs to this class of proteins. Northern blot analysis confirmed that the expression level of Ntsp1 was high only in the soldier head. In addition, the localization of Ntsp1 expression was limited in epithelial cells of the frontal gland reservoir, suggesting that this protein binds to some terpenoid(s) preserved in the frontal gland reservoir. 相似文献
68.
S Yano H Ohi M Ashizaki M Obata Y Mikata R Tanaka T Nishioka I Kinoshita Y Sugai I Okura S Ogura JA Czaplewska M Gottschaldt US Schubert T Funabiki K Morimoto M Nakai 《Chemistry & biodiversity》2012,9(9):1903-1915
Four platinum(II) and palladium(II) complexes with sugar-conjugated bipyridine-type triazole ligands, [Pt(II) Cl(2) (AcGlc-pyta)] (3), [Pd(II) Cl(2) (AcGlc-pyta)] (4), [Pt(II) Cl(2) (Glc-pyta)] (5), and [Pd(II) Cl(2) (Glc-pyta)] (6), were prepared and characterized by mass spectrometry, elemental analysis, (1) H- and (13) C-NMR, IR as well as UV/VIS spectroscopy, where AcGlc-pyta and Glc-pyta denote 2-[4-(pyridin-2-yl)-1H-1,2,3-triazol-1-yl]ethyl 2,3,4,6-tetra-O-acetyl-β-D-glucopyranoside (1) and 2-[4-(pyridin-2-yl)-1H-1,2,3-triazol-1-yl]ethyl β-D-glucopyranoside (2), respectively. The solid-state structure of complex 6 was determined by single-crystal X-ray-diffraction analysis. These complexes exhibited in vitro cytotoxicity against human cervix tumor cells (HeLa) though weaker than that of cisplatin. 相似文献
69.
Identification of a New Borrelia Species among Small Mammals in Areas of Northern Spain Where Lyme Disease Is Endemic 下载免费PDF全文
Horacio Gil Marta Barral Raquel Escudero Ana L. García-Pérez Pedro Anda 《Applied microbiology》2005,71(3):1336-1345
The role of small mammals as reservoir hosts for Borrelia burgdorferi was investigated in several areas where Lyme disease is endemic in northern Spain. A low rate of infestation by Ixodes ricinus nymphs was found in the small mammal populations studied that correlated with the near-absence of B. burgdorferi sensu lato in 184 animals tested and with the lack of transmission of B. burgdorferi sensu lato to I. ricinus larvae that fed on them. In contrast, questing ticks collected at the same time and in the same areas were found to carry a highly variable B. burgdorferi sensu lato repertoire (B. burgdorferi sensu stricto, Borrelia garinii, Borrelia valaisiana, and Borrelia afzelii). Interestingly, the only isolate obtained from small mammals (R57, isolated from a bank vole) grouped by phylogenetic analyses with other Borrelia species but in a separate clade from the Lyme disease and relapsing fever organisms, suggesting that it is a new species. This new agent was widely distributed among small mammals, with infection rates of 8.5 to 12% by PCR. Moreover, a high seroprevalence to B. burgdorferi sensu lato was found in the animal sera, suggesting cross-reactivity between B. burgdorferi sensu lato and R57. Although small mammals do not seem to play an important role as reservoirs for B. burgdorferi sensu lato in the study area, they seem to be implicated in the maintenance of spirochetes similar to R57. 相似文献
70.
A role for macrophage migration inhibitory factor in the neonatal respiratory distress syndrome 总被引:1,自引:0,他引:1
Kevill KA Bhandari V Kettunen M Leng L Fan J Mizue Y Dzuira JD Reyes-Mugica M McDonald CL Baugh JA O'Connor CL Aghai ZH Donnelly SC Bazzy-Asaad A Bucala RJ 《Journal of immunology (Baltimore, Md. : 1950)》2008,180(1):601-608
Using a mouse model of neonatal respiratory distress syndrome (RDS), we demonstrate a central role for macrophage migration inhibitory factor (MIF) in lung maturation at the developmental stage when human neonates are most susceptible to RDS. We prematurely delivered mouse pups at embryonic day 18, during the early saccular stage of pulmonary development. Only 8% of the prematurely delivered pups genetically deficient in MIF survived 8 h vs 75% of wild-type controls (p<0.001). This phenotype was corrected when pups of all genotypes were bred from dams heterozygote for MIF deficiency. Local production of MIF in the lung increased at embryonic day 18, continued until full-term at embryonic day 19.5, and decreased in adulthood, thus coinciding with this developmental window. The lungs of pups genetically deficient in MIF were less mature upon histological evaluation, and demonstrated lower levels of vascular endothelial growth factor and corticosterone--two factors that promote fetal lung maturation. In vitro studies support a role for MIF in surfactant production by pulmonary epithelial cells. In a cohort of human neonates with RDS, higher intrapulmonary MIF levels were associated with a lower likelihood of developing bronchopulmonary dysplasia, a sequelae of RDS (p<0.03). This study demonstrates for the first time a role for MIF in lung maturation, and supports a protective role for MIF in newborn lung disease. 相似文献