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951.
952.
Hsu EC Lin YC Hung CS Huang CJ Lee MY Yang SC Ting LP 《Journal of biomedical science》2007,14(6):731-744
Summary Protein-tyrosine phosphatase PTPN3 is a membrane-associated non-receptor protein-tyrosine phosphatase. PTPN3 contains a N-terminal
FERM domain, a middle PDZ domain, and a C-terminal phosphatase domain. Upon co-expression of PTPN3, the level of human hepatitis
B viral (HBV) RNAs, 3.5 kb, 2.4/2.1 kb, and 0.7 kb transcribed from a replicating HBV expression plasmid is significantly
reduced in human hepatoma HuH-7 cells. When the expression of endogenous PTPN3 protein is diminished by specific small interfering
RNA, the expression of HBV genes is enhanced, indicating that the endogenous PTPN3 indeed plays a suppressive role on HBV
gene expression. PTPN3 can interact with HBV core protein. The interaction is mediated via the PDZ domain of PTPN3 and the
carboxyl-terminal last four amino acids of core. Either deletion of PDZ domain of PTPN3 or substitution of PDZ ligand in core
has no effect on PTPN3-mediated suppression. These results clearly show that the interaction of PTPN3 with core is not required
for PTPN3 suppressive effect. Mutation of 359serine and 835serine of 14-3-3β binding sites to alanine, which slightly reduces the interaction with 14-3-3β, does not influence the PTPN3
effect. In contrast, mutation of the invariant 842cysteine residue in phosphatase domain to serine, which makes the phosphatase activity inactive, does not change its subcellular
localization and interaction with core or 14-3-3β, but completely abolishes PTPN3-mediated suppression. Furthermore, deletion
of FERM domain does not affect the phosphatase activity or interaction with 14-3-3β, but changes the subcellular localization
from cytoskeleton-membrane interface to cytoplasm and nucleus, abolishes binding to core, and diminishes the PTPN3 effect
on HBV gene expression. Taken together, these results demonstrate that the phosphatase activity and FERM domain of PTPN3 are
essential for its suppression of HBV gene expression.
En-Chi Hsu, Yen-Cheng Lin have equal contributions to this work. 相似文献
953.
Dengue viruses are mosquito-borne flaviviruses and may cause the life-threatening dengue hemorrhagic fever and dengue shock
syndrome. Its envelope protein is responsible mainly for the virus attachment and entry to host cells. To identify the human
cellular proteins interacting with the envelope protein of dengue virus serotype 2 inside host cells, we have performed a
screening with the yeast-two-hybrid-based “Functional Yeast Array”. Interestingly, the small ubiquitin-like modifier-1 conjugating
enzyme 9 protein, modulating cellular processes such as those regulating signal transduction and cell growth, was one of the
candidates interacting with the dengue virus envelope protein. With co-precipitation assay, we have demonstrated that it indeed
could interact directly with the Ubc9 protein. Site-directed mutagenesis has demonstrated that Ubc9 might interact with the
E protein via amino acid residues K51 and K241. Furthermore, immunofluorescence microscopy has shown that the DV2E-EGFP proteins
tended to progress toward the nuclear membrane and co-localized with Flag-Ubc9 proteins around the nuclear membrane in the
cytoplasmic side, and DV2E-EGFP also shifted the distribution of Flag-Ubc9 from evenly in the nucleus toward concentrating
around the nuclear membrane in the nucleic side. In addition, over-expression of Ubc9 could reduce the plaque formation of
the dengue virus in mammalian cells. This is the first report that DV envelope proteins can interact with the protein of sumoylation
system and Ubc9 may involve in the host defense system to prevent virus propagation. 相似文献
954.
Jørgensen JB Johansen A Hegseth MN Zou J Robertsen B Collet B Secombes CJ 《Fish & shellfish immunology》2007,23(6):1294-1303
A transgenic cell line for the detection of salmon interferons (IFNs) has been established. It is based on a CHSE-214 cell line containing a reporter construct expressing firefly luciferase under the control of the rainbow trout promoter for the IFN-induced Mx1 gene. This cell line, named CHSE-Mx10, showed IFN-induced luciferase expression after more than 80 passages, confirming the stability of this cell line. Interestingly, the Mx promoter was shown to respond to both salmon IFN-alpha/beta and trout IFN-gamma in a dose-dependent manner, while there was no response to TNF-alpha and IL-1beta. IFN-alpha/beta activity could be measured at a range of 9-150 U/ml, and IFN-gamma showed activity between 10 and 100 ng/ml. The reproducibility of both responses was good. The CHSE-Mx10 reporter system constitutes a versatile tool to study the induction and regulation of IFN signaling in teleost fish. A preliminary study presented herein suggests that both infectious pancreas necrosis virus (IPNV) and salmon pancreas disease virus (SPDV) may block activation of the Mx promoter in CHSE-Mx10 stimulated with IFN-alpha/beta. 相似文献
955.
A CpG oligodeoxynucleotide inducing anti-coxsackie B3 virus activity in human peripheral blood mononuclear cells 总被引:2,自引:0,他引:2
Cong Z Wan M Wu X Wang L Hu X Yang F Bao M Zhang X Chen J Wang L Yu Y 《FEMS immunology and medical microbiology》2007,51(1):26-34
Coxsackie B3 virus (CVB3) is the most significant pathogen causing myocarditis in humans, and antiviral therapy would be most effective in the early stages of the disease. Here we provide evidence that BW001, a C-type CpG oligodeoxynucleotide, induces anti-CVB3 activity in human peripheral blood mononuclear cells (PBMCs). In parallel, we have demonstrated that BW001 induces human PBMCs to express mRNAs of multiple types of interferon (IFN), including IFN-alpha, IFN-beta, IFN-omega and IFN-gamma, and to express mRNAs of at least 11 subtypes of IFN-alpha. The induced IFNs may contribute to the anti-CVB3 activity. The results suggest that BW001 could be developed into a medication with the potential to treat CVB3 infectious diseases by inducing natural mixed IFNs. 相似文献
956.
JAIME POLOP GLADYS CALDER
N MARÍA ROSA FEUILLADE JORGE GARCÍA DELIA ENRIA MARTA SABATTINI 《Austral ecology》2007,32(3):245-253
Abstract Argentine haemorrhagic fever (AHF) is caused by Junin (JUN) virus, which is hosted by the drylands vesper mouse (Calomys musculinus). In this work we monitored population abundance of C. musculinus and rodent assemblages for 3 years in and outside the AHF endemic zones (northern Buenos Aires, southern Córdoba and Santa Fe Provinces, Argentina). The study area was divided into endemic and nonendemic zones. In the endemic zone epidemic sites were recognized, characterized by recent emergence and maintenance of AHF cases, and also historical sites, characterized by decreased incidence or disappearance of AHF human cases. In the nonendemic zone AHF has never been recognized. Although differences were statistically significant only during some periods, population abundance of C. musculinus was usually lower in the nonendemic sites. The pattern and magnitude of seasonal fluctuations in C. musculinus populations were also distinct in the nonendemic sites as compared to endemic sites. The relative abundance of C. musculinus in rodent assemblage was lower in nonendemic sites than in the endemic sites. The lower population densities and dampened seasonal dynamics may be at least partly responsible for the absence of AHF cases in the nonendemic zone. It is suggested that the balance between intra and interspecific interactions might be the cause of the pattern of incidence and prevalence of pathogens in the host species. 相似文献
957.
Shepherd DN Mangwende T Martin DP Bezuidenhout M Kloppers FJ Carolissen CH Monjane AL Rybicki EP Thomson JA 《Plant biotechnology journal》2007,5(6):759-767
In this article, we report transgene-derived resistance in maize to the severe pathogen maize streak virus (MSV). The mutated MSV replication-associated protein gene that was used to transform maize showed stable expression to the fourth generation. Transgenic T2 and T3 plants displayed a significant delay in symptom development, a decrease in symptom severity and higher survival rates than non-transgenic plants after MSV challenge, as did a transgenic hybrid made by crossing T2 Hi-II with the widely grown, commercial, highly MSV-susceptible, white maize genotype WM3. To the best of our knowledge, this is the first maize to be developed with transgenic MSV resistance and the first all-African-produced genetically modified crop plant. 相似文献
958.
《Journal of molecular biology》2022,434(6):167277
Establishment of the interferon (IFN)-mediated antiviral state provides a crucial initial line of defense against viral infection. Numerous genes that contribute to this antiviral state remain to be identified. Using a loss-of-function strategy, we screened an original library of 1156 siRNAs targeting 386 individual curated human genes in stimulated microglial cells infected with Zika virus (ZIKV), an emerging RNA virus that belongs to the flavivirus genus. The screen recovered twenty-one potential host proteins that modulate ZIKV replication in an IFN-dependent manner, including the previously known IFITM3 and LY6E. Further characterization contributed to delineate the spectrum of action of these genes towards other pathogenic RNA viruses, including Hepatitis C virus and SARS-CoV-2. Our data revealed that APOL3 acts as a proviral factor for ZIKV and several other related and unrelated RNA viruses. In addition, we showed that MTA2, a chromatin remodeling factor, possesses potent flavivirus-specific antiviral functions induced by IFN. Our work identified previously unrecognized genes that modulate the replication of RNA viruses in an IFN-dependent manner, opening new perspectives to target weakness points in the life cycle of these viruses. 相似文献
959.
Initial gene vector dosing for studying symptomatology of amyotrophic lateral sclerosis in non‐human primates 下载免费PDF全文
960.