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141.
142.
Lucia Novakova Kristina Kovacovicova Thanh Quang Dang-Nguyen Martin Sodek Michal Skultety Martin Anger 《PloS one》2016,11(2)
Proper assembly of the spindle apparatus is crucially important for faithful chromosome segregation during anaphase. Thanks to the effort over the last decades, we have very detailed information about many events leading to spindle assembly and chromosome segregation, however we still do not understand certain aspects, including, for example, spindle length control. When tight regulation of spindle size is lost, chromosome segregation errors emerge. Currently, there are several hypotheses trying to explain the molecular mechanism of spindle length control. The number of kinetochores, activity of molecular rulers, intracellular gradients, cell size, limiting spindle components, and the balance of the spindle forces seem to contribute to spindle size regulation, however some of these mechanisms are likely specific to a particular cell type. In search for a general regulatory mechanism, in our study we focused on the role of cell size and nuclear to cytoplasmic ratio in this process. To this end, we used relatively large cells isolated from 2-cell mouse embryos. Our results showed that the spindle size upper limit is not reached in these cells and suggest that accurate control of spindle length requires balanced ratio between nuclear and cytoplasmic volumes. 相似文献
143.
Purification and characterization of mRNA from soybean seeds. Identification of glycinin and beta-conglycinin precursors 总被引:15,自引:0,他引:15
Poly(A)-rich RNA was isolated from developing soybean seeds (Glycine max (L.) Merr.) and fractionated on linear log sucrose gradients. Two major fractions sedimenting at 18 S and 20 S were separated and then purified by further sucrose gradient fractionation. Both fractions were active as messengers when added to a rabbit reticulocyte lysate protein synthesis system. The 18 S fraction caused proteins migrating primarily to the 60,000-dalton region of a sodium dodecyl sulfate gel to be produced, while translation of the 20 S fraction preferentially directed the synthesis of polypeptides similar in size to the alpha and alpha' subunits of beta-conglycinin. Evidence that many of the 60,000-dalton polypeptides were related to glycinin and the high molecular weight 20 S translation products were related to beta-conglycinin was obtained by immunoprecipitation using monospecific antibodies against glycinin and beta-conglycinin, respectively. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the immunoprecipitated products revealed that the glycinin precursor region contained at least three different size components and that the family of glycinin precursors had larger apparent molecular weight (58,000-63,000) than the disulfide-linked complexes between acidic and basic glycinin subunits (57,000). Unlike the disulfide-linked glycinin complexes which were cleaved by disulfide reduction, glycinin precursors were insensitive to reducing agents. The alpha and alpha' subunits synthesized in vitro also had slightly larger apparent molecular weights than purified alpha and alpha' standards. 相似文献
144.
In vitro flowers have been obtained by culturing thin epidermal cell layers of a partial somatic intergeneric hybrid. The phenotype of these flowers differs from that of flowers formed on seed-grown plants (in situ flowers) and from that of flowers of either parental line. In addition, modifications in the phenotype were observed when cultures were sustained for more than four months. Dimorphic leaves present in juvenile and adult stages of mother plants of Nicotiana plumbaginifolia and the somatic hybrid were formed on different ends of the thin epidermal cell layers. No anomalies were observed during microsporogenesis and in the meiotic and mitotic figures of the somatic hybrid, which resembled those of Nicotiana plumbaginifolia. 相似文献
145.
In this work, we studied the chronesthesia of 1,25-dihydroxyvitamin D 3 (1,25(OH) 2 D 3 ), cobalt (II) chloride and of the complex [CoCl 2 (1,25(OH) 2 D 3 ) 4 ]. The study was carried out in spring and autumn on AP and ?-GT activities in brain and kidney of rats during the rodents' active period. In rat brain, in both seasons, 1,25(OH) 2 D 3 enhanced AP activity by 59 % in spring and 21 % in autumn and ?-GT by 39 and 35 % respectively. Cobalt (II) stimulated AP activity by 34 and 29 % respectively. The complex was mainly active on ?-GT activity (70 and 36 %) showing a synergic effect on ?-GT activity in June. In rat kidney, during spring, the induction of AP activity for 1,25(OH) 2 D 3 , cobalt (II) chloride and their complex was, respectively 21, 18 and 12 %. The ?-GT activity was not modified during this period, whereas in autumn, it was inhibited by -33, -50 and -28 %. The AP activity in autumn was not altered. We conclude that the effects on the two enzymatic markers of the three compounds 1,25(OH) 2 D 3 , cobalt (II) chloride and [CoCl 2 (1,25(OH) 2 D 3 ) 4 ] are quite different in Spring and Autumn, and this is explained on the basis of chronesthesia. 相似文献
146.
Different types of morphogenesis in thin cell layers of Nicotiana tabacum cv. Samsun were studied in relation to changes in the external H+ concentration during cluture. Different initial pHs of the medium, ranging from 3.83 to 6.35, were tested under unbuffered and MES-buffered conditions, in combination with various amounts of indolyl-3-butyric acid and kinetin. The explants were sequentially transferred from MES-free media to MES-supplemented media, as well as reciprocally, to determine possible periods during the morphogenic process that showed a particular sensitivity to the external pH. Starting from pH 3.83, 36 m M MES induced the formation of limited callus and of vegetative and floral shoots as flowers in the control. MES at 50 m M inhibited rhizogenesis and either prevented morphogenesis or induced vegetative buds or flowers, depending on the initial pH. The 4th day of culture was a determining period in the induction of roots and flowers. Rhizogenesis, but not floral or vegetative organogenesis, was related to the theoretical intracellular concentration of indolyl-3-butyric acid. H+ transport might be involved in the regulation of morphogenesis. 相似文献
147.
Sachiyo Sanada-Morimura Shinji Sakumoto Reiko Ohtsu Akira Otuka Shou-Horng Huang Dinh Van Thanh Masaya Matsumura 《Applied Entomology and Zoology》2011,46(1):65-73
The small brown planthopper, Laodelphax striatellus, is one of the most serious pest insects of rice plants. A large migration of the insects from overseas was reported in western
parts of Japan in June 2008. Insecticide resistance to imidacloprid, fipronil and BPMC was compared among local populations
in these western regions after migration. The insecticides were applied to the insects using a topical application method.
In some populations, the resistance status coincided with that of the immigrant insects just after migration, i.e., resistance
to imidacloprid but susceptibility to fipronil. In other populations, resistance was observed not only against imidacloprid
but also fipronil. It is likely that the status of the latter populations resulted from intercrossing between domestic populations
of the insects and migrants. Insecticide resistance was also assessed in other areas of northern and eastern parts of Japan.
In general, these populations showed relatively low resistance, although resistance to fipronil was high in the eastern part
of Japan where the density of domestic populations has recently increased. Insecticide susceptibilities were also assessed
in several sites in Taiwan and the northern parts of Vietnam. Although susceptibilities differed among these sites or countries,
they have recently seen a decline for all three insecticides. 相似文献
148.
Wolstencroft EC Simic G thi Man N Holt I Lam le T Buckland PR Morris GE 《Journal of molecular histology》2007,38(4):333-340
Five subtypes of dopamine receptor exist in two subfamilies: two D1-like (D1 and D5) and three D2-like (D2, D3 and D4). We produced novel monoclonal antibodies against all three D2-like receptors and used them to localize receptors in Ntera-2 (NT-2) cells, the human neuronal precursor cell line. Most
of the immunostaining for all three receptors colocalized with mannose-6-phosphate receptor, a marker for late endosomes formed
by internalization of the plasma membrane. This result was obtained with antibodies against three different epitopes on the
D3 receptor, to rule out the possibility of cross-reaction with another protein, and controls without primary antibody or in
the presence of competitor antigen were completely negative. In rat cerebral cortex and hippocampus, some of the dopamine
receptor staining was found in similar structures in neuronal cell cytoplasm. Only some of the neurons were positive for dopamine
receptors and the pattern was consistent with previously-reported patterns of innervation by dopamine-producing neurons. Endosomal
dopamine receptors may provide a useful method for identifying cell bodies of dopamine-responsive neurons to complement methods
that detect only active receptors in the neuronal cell membrane. 相似文献
149.
Chandran Ramakrishna Adrianna Ferraioli Aleth Calle Thanh K. Nguyen Harry Openshaw Patric S. Lundberg Patrick Lomonte Edouard M. Cantin 《PLoS pathogens》2015,11(3)
The establishment of latent infections in sensory neurons is a remarkably effective immune evasion strategy that accounts for the widespread dissemination of life long Herpes Simplex Virus type 1 (HSV1) infections in humans. Periodic reactivation of latent virus results in asymptomatic shedding and transmission of HSV1 or recurrent disease that is usually mild but can be severe. An in-depth understanding of the mechanisms regulating the maintenance of latency and reactivation are essential for developing new approaches to block reactivation. However, the lack of a reliable mouse model that supports efficient in vivo reactivation (IVR) resulting in production of infectious HSV1 and/or disease has hampered progress. Since HSV1 reactivation is enhanced in immunosuppressed hosts, we exploited the antiviral and immunomodulatory activities of IVIG (intravenous immunoglobulins) to promote survival of latently infected immunodeficient Rag mice. Latently infected Rag mice derived by high dose (HD), but not low dose (LD), HSV1 inoculation exhibited spontaneous reactivation. Following hyperthermia stress (HS), the majority of HD inoculated mice developed HSV1 encephalitis (HSE) rapidly and synchronously, whereas for LD inoculated mice reactivated HSV1 persisted only transiently in trigeminal ganglia (Tg). T cells, but not B cells, were required to suppress spontaneous reactivation in HD inoculated latently infected mice. Transfer of HSV1 memory but not OVA specific or naïve T cells prior to HS blocked IVR, revealing the utility of this powerful Rag latency model for studying immune mechanisms involved in control of reactivation. Crossing Rag mice to various knockout strains and infecting them with wild type or mutant HSV1 strains is expected to provide novel insights into the role of specific cellular and viral genes in reactivation, thereby facilitating identification of new targets with the potential to block reactivation. 相似文献
150.
The Vietnam Initiative on Zoonotic Infections (VIZIONS): A Strategic Approach to Studying Emerging Zoonotic Infectious Diseases 总被引:1,自引:0,他引:1
Maia A. Rabaa Ngo Tri Tue Tran My Phuc Juan Carrique-Mas Karen Saylors Matthew Cotten Juliet E. Bryant Ho Dang Trung Nghia Nguyen Van Cuong Hong Anh Pham Alessandra Berto Voong Vinh Phat Tran Thi Ngoc Dung Long Hoang Bao Ngo Thi Hoa Heiman Wertheim Behzad Nadjm Corina Monagin H. Rogier van Doorn Motiur Rahman My Phan Vu Tra James I. Campbell Maciej F. Boni Pham Thi Thanh Tam Lia van der Hoek Peter Simmonds Andrew Rambaut Tran Khanh Toan Nguyen Van Vinh Chau Tran Tinh Hien Nathan Wolfe Jeremy J. Farrar Guy Thwaites Paul Kellam Mark E. J. Woolhouse Stephen Baker 《EcoHealth》2015,12(4):726-735