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151.
152.
Takuya Kobayakawa Nami Ohashi Yuki Hirota Kohei Takahashi Yuko Yamada Tetsuo Narumi Kazuhisa Yoshimura Shuzo Matsushita Shigeyoshi Harada Hirokazu Tamamura 《Bioorganic & medicinal chemistry》2018,26(21):5664-5671
CD4 mimics such as YIR-821 and its derivatives are small molecules which inhibit the interaction between the Phe43 cavity of HIV-1 gp120 with host CD4, an interaction that is involved in the entry of HIV to cells. Known CD4 mimics generally possess three structural features, an aromatic ring, an oxalamide linker and a piperidine moiety. We have shown previously that introduction of a cyclohexyl group and a guanidine group into the piperidine moiety and a fluorine atom at the meta-position of the aromatic ring leads to a significant increase in the anti-HIV activity. In the current study, the effects of conformational flexibility were investigated by introduction of an indole-type group in the junction between the oxalamide linker and the aromatic moiety or by replacement of the oxalamide linker with a glycine linker. This led to the development of compounds with high anti-HIV activity, showing the importance of the junction region for the expression of high anti-HIV activity. The present data are expected to be useful in the future design of novel CD4 mimic molecules. 相似文献
153.
Populations of forms intermediate between Carabus (Ohomopterus) insulicola and Carabus (Ohomopterus) arrowianus occur at the boundaries between the two species in the Kiso Valley, Nagano Prefecture, central Honshu, Japan. Morphological and mitochondrial DNA analyses revealed that these populations are derived from a hybrid swarm established as a result of secondary contact between the two species. A similar hybrid swarm has been reported in the Ina Valley, an adjacent river basin separated by the Kiso Mountain Range, where the two species are distributed parapatrically. The hybrid swarm individuals in the two valleys show parallelism in the morphological evolution of the male genitalia upon secondary contact and subsequent formation of hybrid swarms between the two Carabus species. 相似文献
154.
Emi Takeda Kohei Kunimoto Yoshito Kawai Misumi Kataoka Kazuhiko Ishikawa Takashi Nakamura 《Extremophiles : life under extreme conditions》2016,20(5):733-745
O-Phosphoserine sulfhydrylase (OPSS) synthesizes cysteine from O-phospho-l-serine (OPS) and sulfide. We have determined the three-dimensional structures of OPSS from hyperthermophilic archaeon Aeropyrum pernix K1 (ApOPSS) in complex with aminoacrylate intermediate (AA) formed from pyridoxal 5′-phosphate with OPS or in complex with cysteine and compared them with that of ApOPSS. We found an orientational change of F225 at the active-site entrance and constructed an F225A mutant to examine its activities and AA stability and clarify the role of F225 in ApOPSS. The OPS and O-acetyl-l-serine (OAS) sulfhydrylase activities of the F225A mutant decreased by 4.2- and 15-fold compared to those of the wild-type (wt) ApOPSS, respectively. The ability of OPS and OAS to form AA also decreased by 12- and 27-fold, respectively. AA was less stable in the F225A mutant than in the wt ApOPSS. Simulated docking showed that leaving groups, such as phosphate and acetate, were oriented to the inside of the active site in the F225A mutant, whereas they were oriented to the entrance in the wt ApOPSS. These results suggest that F225 in ApOPSS plays important roles in maintaining the hydrophobic environment of AA from solvent water and in controlling the orientation of leaving groups. 相似文献
155.
Obata M Hirohara S Sharyo K Alitomo H Kajiwara K Ogata S Tanihara M Ohtsuki C Yano S 《Biochimica et biophysica acta》2007,1770(8):1204-1211
156.
Kazuhiko Mochida Tomoko Kondo Takahiro Matsubara Shinji Adachi and Kohei Yamauchi 《Development, growth & differentiation》1999,41(5):619-627
Sperm that have acquired potential for motility are kept immotile in seminal plasma in the teleost, Nile tilapia. In order to investigate the mechanism of immobilization, several experiments were performed using a previously characterized monoclonal antibody (TAT-30) against a molecular weight (Mr) = 120,000 protein that is secreted by Sertoli cells and epithelial cells of the sperm duct, and is also bound to the head of the spermatozoon. First, we assessed sperm motility in the seminal plasma protein fraction (SPP), and demonstrated that the sperm motility is inhibited by SPP in a concentration-dependent manner. Furthermore, sperm motility was recovered if SPP was pretreated with TAT-30, suggesting that the TAT-30 antigen is one of the components of the sperm immobilizing factor. Calibration by gel filtration followed by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting with TAT-30 demonstrated that the sperm immobilizing factor was more than Mr = 1,000,000 in seminal plasma, suggesting that it is a homopolymer of the Mr = 120,000-TAT-30 positive protein. Additionally, lectin blot analysis showed that the TAT-30 antigen was reactive with Lens culinarin agglutinin (LCA) and Conavalia ensiformis agglutinin (ConA), indicating that it is a glycoprotein. Immunohistochemical studies showed that the TAT-30 antigen was localized specifically on the heads of spermatozoa and on the apical surface, lysosomes and rough endoplasmic reticulum of Sertoli cells. 相似文献
157.
Chromosomal localization of three human genes encoding bone morphogenetic protein receptors 总被引:7,自引:0,他引:7
Anna-Karin Åström Donald Jin Takeshi Imamura Eva Röijer Bradley Rosenzweig Kohei Miyazono Peter ten Dijke Göran Stenman 《Mammalian genome》1999,10(3):299-302
Bone morphogenetic proteins (BMPs) are members of the TGF-β superfamily that play a pivotal role in bone formation during
embryogenesis and fracture repair. BMP signaling occurs via hetero-oligomeric serine/threonine kinase complexes of BMP type
I (BMPR-IA or BMPR-IB) and type II receptors (BMPR-II). BMPR-IA and IB are closely related receptors, with sequence differences
conserved between different species, suggesting that they serve distinct functions. Here we report the cDNA cloning of human
BMPR1B and the chromosomal localization of all three BMPR genes. Using somatic cell hybrid and FISH analyses, the BMPR1A,
BMPR1B, and BMPR2 genes were assigned to 10q23, 4q22-24, and 2q33-34, respectively. A processed BMPR1A pseudogene was mapped
to 6q23.
Received: 17 February 1997 / Accepted: 15 October 1998 相似文献
158.
Yoshikazu Watanabe Kohei Hayashida Daisuke Saito Toshihiro Takahashi Junichi Sakai Eriko Nakata Takashi Kanda Takashi Iwai Shigeto Hirayama Hideaki Fujii Tomio Yamakawa Hiroshi Nagase 《Bioorganic & medicinal chemistry letters》2017,27(15):3495-3498
We designed and synthesized novel δ opioid receptor (DOR) agonists 3a–i with an azatricyclodecane skeleton, which was a novel structural class of DOR agonists. Among them, 3b exhibited high values of binding affinity and potent agonistic activity for the DOR that were approximately equivalent to those of 2 which bore an oxazatricyclodecane skeleton. In vitro assays using the blood-brain barrier (BBB) permeability test kit supported the idea that 3b achieved an excellent BBB permeability by converting an oxygen atom of 2 to a carbon atom (methylene group) in the core skeleton. As a result, 3b showed potent antinociceptive effects. 相似文献
159.
Astrocytes with previous chronic exposure to amyloid β‐peptide fragment 1–40 suppress excitatory synaptic transmission 下载免费PDF全文
Hiroyuki Kawano Kohei Oyabu Hideaki Yamamoto Kei Eto Yuna Adaniya Kaori Kubota Takuya Watanabe Ayumi Hirano‐Iwata Junichi Nabekura Shutaro Katsurabayashi Katsunori Iwasaki 《Journal of neurochemistry》2017,143(6):624-634
160.
Cephalopods are able to control their arms sophisticatedly and use them for various behaviors, such as camouflage, startling predators and hunting prey. Here, we report a previously undescribed arm-flapping behavior of the pharaoh cuttlefish, Sepia pharaonis, observed in captivity. S. pharaonis raised the first pair of arms and wrinkled the parts near the distal end, where the skin color was darkened. Additionally, S. pharaonis spread the second and third pairs of arms and bent them as if they were jointed, and flapped the distal ends. S. pharaonis showed this behavior in two different situations: after being introduced into a large space, and during hunting. We discuss the putative functions of this behavior, including possible mimicry of a hermit crab, considering the situations in which the behavior was observed. 相似文献