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911.
Koichiro Abe Kimi Araki Maya Tanigawa Kei Semba Takashi Ando Masahiro Sato Daisuke Sakai Akihiko Hiyama Joji Mochida Ken‐Ichi Yamamura 《Genesis (New York, N.Y. : 2000)》2012,50(10):758-765
Sickle tail (Skt) was originally identified by gene trap mutagenesis in mice, and the trapped gene is highly expressed in the notochord, intervertebral discs (IVD), and mesonephros. Here, we report the generation of Sktcre mice expressing Cre recombinase in the IVD due to target insertion of the cre gene into the Skt locus by recombinase‐mediated cassette exchange. Crossing a conditional lacZ Reporter (R26R), Cre expression from the Sktcre allele specifically activates β‐galactosidase expression in the whole notochord from E9.5 onwards. In E15.5 Sktcre;R26R embryos, reporter activity was detected in the nucleus pulposus and in a portion of the annulus fibrosus, resulting in expansion of Cre‐expressing cells in the adult IVD. Reporter activity was also seen in the Sktcre;R26R mesonephros at E15.5. These results suggest that Sktcre mice are useful for exploring the fate specification of notochordal cells and creating models for IVD‐related skeletal diseases. genesis 50:758–765, 2012. © 2012 Wiley Periodicals, Inc. 相似文献
912.
During over a decade of study on aspartic protease inhibitors and water-soluble prodrugs, in 2003, we discovered that the presence of an O-acyl instead of N-acyl residue within the peptide backbone significantly changed the secondary structure of the native peptide. In addition, the target peptide was subsequently generated by an O-N intramolecular acyl migration reaction. These findings led to the development of a novel method, called "O-acyl isopeptide method," for the synthesis of peptides containing difficult sequence. Further application of the method to Alzheimer's Abeta1-42 revealed that the O-acyl isopeptide of Abeta1-42 could be effectively synthesized and stored without spontaneous self-assembly. Intact monomer Abeta1-42 could then be obtained from the isopeptide under physiological experimental conditions. We named the O-acyl isopeptide as "Click Peptide," because of its "quick and easy one-way conversion" to the parent Abeta1- 42. Application of the click peptide has provided a new basis for the investigation of the biological functions of Abeta1-42 by inducible activation of its self-assembly. The O-acyl isopeptide method has further evolved as a general method for peptides synthesis with our recent developments of "O-acyl isodipeptide units" and "racemization-free segment condensation methodology." Isodipeptide units have enabled routine use of the O-acyl isopeptide method by avoiding the often difficult esterification reaction on resin. "Racemizationfree segment condensation methodology" has been achieved by employing N-segments possessing a C-terminal urethaneprotected O-acyl Ser/Thr residues. The synthesis of long peptides/proteins by racemization-free segment condensation has thus become possible at Ser/Thr residues instead of Cterminal Gly/Pro residues. As the O-acyl isopeptide method becomes more widely utilized, we have composed this review to facilitate its application for the production of peptides and proteins. 相似文献
913.
Oyamada H Ogawa Y Shibata N Okawa Y Suzuki S Kobayashi H 《Archives of microbiology》2008,189(5):483-490
We investigated the structural and immunochemical characteristics of cell wall mannan obtained from Candida sojae JCM 1644, which is a new yeast species isolated from defatted soybean flakes. The results of a slide-agglutination test and
of an enzyme-linked immunosorbent assay using anti-factor sera to the pathogenic Candida species indicated that the cells and the C. sojae mannan were cross-reactive to the specific anti-factor sera against Candida albicans serotype A (FAb 6) and Candida guilliermondii (FAb 9). Two-dimensional homonuclear Hartmann–Hahn analysis indicated that the mannan consisted of various linked oligomannosyl
side chains containing α-1,2-, α-1,3-, α-1,6- and β-1,2-linked mannose residues. However, although the determinants of antigenic
factors 6 and 9 could be not found in this mannan, branched side chains, Manβ1-2Manα1-3[Manα1-6]Manα1-(2Manα1-)n2Man and a
linear α-1,6-linked polymannosyl backbone, which are cross-reacted by FAbs 6 and 9, respectively, were identified. The mannan
was subjected to acetolysis in order to determine the polymerization length of the α-1,2-linked oligomannosyl residue in the
side chains. The result of 1H-nuclear magnetic resonance analysis of the released oligosaccharides showed that the remarkable regularity in the length
of α-1,2-linked oligomannosyl side chains, which were previously found in mannans of other Candida species, is not observed in this mannan. 相似文献
914.
E6AP ubiquitin ligase mediates ubiquitylation and degradation of hepatitis C virus core protein 下载免费PDF全文
Shirakura M Murakami K Ichimura T Suzuki R Shimoji T Fukuda K Abe K Sato S Fukasawa M Yamakawa Y Nishijima M Moriishi K Matsuura Y Wakita T Suzuki T Howley PM Miyamura T Shoji I 《Journal of virology》2007,81(3):1174-1185
Hepatitis C virus (HCV) core protein is a major component of viral nucleocapsid and a multifunctional protein involved in viral pathogenesis and hepatocarcinogenesis. We previously showed that the HCV core protein is degraded through the ubiquitin-proteasome pathway. However, the molecular machinery for core ubiquitylation is unknown. Using tandem affinity purification, we identified the ubiquitin ligase E6AP as an HCV core-binding protein. E6AP was found to bind to the core protein in vitro and in vivo and promote its degradation in hepatic and nonhepatic cells. Knockdown of endogenous E6AP by RNA interference increased the HCV core protein level. In vitro and in vivo ubiquitylation assays showed that E6AP promotes ubiquitylation of the core protein. Exogenous expression of E6AP decreased intracellular core protein levels and supernatant HCV infectivity titers in the HCV JFH1-infected Huh-7 cells. Furthermore, knockdown of endogenous E6AP by RNA interference increased intracellular core protein levels and supernatant HCV infectivity titers in the HCV JFH1-infected cells. Taken together, our results provide evidence that E6AP mediates ubiquitylation and degradation of HCV core protein. We propose that the E6AP-mediated ubiquitin-proteasome pathway may affect the production of HCV particles through controlling the amounts of viral nucleocapsid protein. 相似文献
915.
Usefulness and limitation of measurement of insulin-like growth factor binding protein-3 (IGFBP-3) for diagnosis of growth hormone deficiency. 总被引:5,自引:0,他引:5
Y Hasegawa T Hasegawa T Aso S Kotoh Y Tsuchiya O Nose Y Ohyama K Araki T Tanaka S Saisyo 《Endocrinologia japonica》1992,39(6):585-591
To analyze the utility of insulin-like growth factor binding protein-3 (IGFBP-3) radioimmunoassay for diagnosis of growth hormone deficiency (GHD) we measured IGFBP-3 in sera from normal children, short children and patients with GHD. The sensitivity (true positive ratio) of IGFBP-3 for complete GHD (cGHD) was 93%, while the specificity (true negative ratio) for normal short children (NS) was 88%. In contrast, the sensitivity of IGFBP-3 for partial GHD (pGHD) was only 43%. The poor discrimination between patients with pGHD and NS may be the result of their relatively similar GH level, as compared to cGHD, or due to the limitations of GH stimulation tests. The specificity of IGFBP-3 for NS was excellent in children of all ages: less than 10 years old (87%) and older than 10 (88%). However, sensitivity for GHD was good for children less than 10 years old (84%) but poor for children older than 10 (64%). IGFBP-3 may be less sensitive for diagnosing GHD in older children because IGFBP-3 levels may also increase during puberty due to mechanisms independent of the GH-IGF-I axis. 相似文献
916.
917.
Chromosomal diagnosis in each individual blastomere of 5- to 10-cell bovine embryos derived from in vitro fertilization 总被引:4,自引:0,他引:4
Yoshizawa M Konno H Zhu S Kageyama S Fukui E Muramatsu S Kim S Araki Y 《Theriogenology》1999,51(7):1239-1250
Chromosomal normality and sex were diagnosed in each blastomere of bovine embryos derived from in vitro fertilization (IVF). Bovine embryos developing to the 5- to 10-cell stage were separated into individual blastomeres with 0.5% protease. After treatment with 100 ng/mL vinblastine sulfate for 8 to 10 h, they were prepared for chromosome samples. In total, 33 bovine embryos and 185 blastomeres were examined. Chromosomal normality was analyzed in 43.8% (81/185) of the blastomeres and 60.6% (20/33) of the embryos; while chromosomal anomalies were found in 16 (80%, 16/20) of the embryos, 5 haploid embryos and 11 mosaic (n/2n) embryos. Mosaicism characteristic of the opposite sex in X-and Y-chromosomes was found in 2 haploid embryos, and that of a Y-chromosome and of XX chromosomes in 1 n/2n embryo. Various sex-chromosome compositions were also observed in the other 10 chromosomal mosaic n/2n embryos. 相似文献
918.
Nobue Kitanaka Junichi Kitanaka Tomohiro Tatsuta Koh-ichi Tanaka Kaname Watabe Nobuyoshi Nishiyama Yoshio Morita Motohiko Takemura 《Neurochemical research》2010,35(5):749-760
A variety of drug treatment regimens have been proposed to model the dysphoric state observed during methamphetamine (METH)
withdrawal in rats, but little has been established in experiments using mice. In male ICR mice, a fixed-dose injection regimen
of METH (1.0 or 2.5 mg/kg, i.p., twice daily for 10 consecutive days) induced a significant decrease in the time spent in
open arms in an elevated plus maze after 5 days of drug abstinence. Under an escalating-dose injection regimen (0.2–2.0 mg/kg,
i.p., 3 times daily for 4 days, total: 15 mg/kg/animal) or continuous subcutaneous administration with osmotic mini-pumps
(15 or 76 mg/kg of METH for 2 weeks), no significant behavioral change was observed after 5 days of drug abstinence, compared
with control animals. Reduced gains in body weight were observed during repeated treatment with METH in the fixed-dose injection
and mini-pump treatment regimens, but not the escalating-dose injection regimen. HPLC analysis revealed significant decreases
in the level of cerebral 3-methoxy-4-hydroxyphenylglycol, a norepinephrine metabolite, and norepinephrine turnover, which
may be attributed to the expression of anxiety-related behavior in the elevated plus maze. These observations suggest that
the mice treated with a fixed-dose of METH may model the anxiety-related behavior observed in the dysphoric state induced
by METH withdrawal in humans. 相似文献
919.
K Fujimoto N Araki K S Ogawa S Kondo T Kitaoka K Ogawa 《The journal of histochemistry and cytochemistry》1989,37(2):249-256
Calmodulin (CaM) has been implicated as a multifunctional regulator of Ca2+ in the cytoplasm of cells. We have recently introduced biologically active colloidal gold-labeled CaM as a marker for identifying potential CaM binding sites (unoccupied by endogenous CaM at the time of fixation) by electron microscopy and have stained frozen thin sections of rat cardiac muscle with this conjugate. In the presence of Ca2+, gold particles indicating CaM binding sites were found localized on the sarcoplasmic reticulum, mitochondria, and gap junctions. Control tissue sections treated with EGTA or exposed to excess amounts of unlabeled native CaM before staining showed no binding. We believe that cytochemistry of potential CaM binding sites revealed by staining with labeled exogenous CaM is useful in correlating known biochemical reactions of CaM with particular cell activities. 相似文献
920.
Inhibition of the Breakdown of Xyloglucans in Azuki Bean Epicotyls by Concanavalin A 总被引:1,自引:0,他引:1
Indole-3-acetic acid at 10 µM caused a 30% decrease inthe weight-average molecular mass of xyloglucans extracted with24% KOH from the cell walls of epicotyl segments of azuki bean(Vigna angularis Ohwi et Ohashi cv. Takara). Concanavalin A(Con A) at 2 g liter1 completely inhibited the IAA-inducedchange in the molecular mass of the xyloglucans. Con A alsosuppressed the autolysis of pectin-depleted cell walls, as wellas the breakdown of xyloglucans by a protein fraction that hadbeen extracted with 1 M NaCl from the cell walls of azuki beanepicotyls. These results indicate that Con A is a potent inhibitorof the breakdown of xyloglucans both in vivo and in vitro. Mostof the activity responsible for the decrease in staining byiodine and the increase in reducing power of solution of xyloglucansin the protein fraction from cell walls bound to a column ofCon A-Sepharose and was eluted by the specific hapten, methyl 相似文献