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131.
We describe a new approach to in vitro DNA recombination termed the Separate-Mixing method in this study. The reaction process
of this method consists of two stages: at the first stage the reaction was implemented in two parallel teams, which generated
random recombination by template-switching of growing poly-nucleotides from primers in the presence of unidirectional single-stranded
DNA fragments used as templates, and then both teams were mixed together for further extension and recombination of DNA sequences
at the second stage. Due to this particular strategy, the reaction process was also accompanied by two other processes of
DNA shuffling and StEP simultaneously. Two AdoMet synthetase genes, sam2 from Saccharomyces cerevisiae and metK from Escherichia coli, which have only 56% homology on the DNA level, were used for recombination with the Separate-Mixing method. DNA recombination
was available after a single round of reaction. When 10 randomly selected recombinants were sequenced, an unshuffled parental
clone was not found, nor was unexpected insertion, deletion, or rearrangement detected. An evolved gene, sam’, was obtained after screening and selection, which could obviously increase the accumulation of AdoMet in S. cerevisiae.
Published in Russian in Molekulyarnaya Biologiya, 2006, Vol. 40, No. 3, pp. 546–553.
This article was submitted by the authors in English. 相似文献
132.
KN Dancause XJ Cao F Veru S Xu H Long C Yu DP Laplante CD Walker S King 《American journal of physical anthropology》2012,149(2):307-311
Stress during the prenatal and early postnatal periods (perinatal stress, PS) is known to impact offspring cognitive, behavioral, and physical development, but effects on skeletal growth are not clear. Our objective was to analyze effects of variable, mild, daily PS exposure on adult offspring long bone length. Twelve pregnant rat dams were randomly assigned to receive variable stress from gestational days 14–21 (Prenatal group), postpartum days 2–9 (Postnatal), both periods (Pre–Post), or no stress (Control). Differences in adult offspring tibia and femur length were analyzed among treatment groups. Mean tibia length differed among groups for males (P = 0.016) and females (P = 0.009), and differences for femur length approached significance for males (P = 0.051). Long bone length was shorter among PS‐exposed offspring, especially those exposed to postnatal stress (Postnatal and Pre–Post groups). Results persisted when controlling for nose–tail length. These differences might reflect early stunting that is maintained in adulthood, or delayed growth among PS‐exposed offspring. This study suggests that PS results in shorter long bones in adulthood, independently of effects on overall body size. Stunting and growth retardation are major global health burdens. Our study adds to a growing body of evidence suggesting that PS is a risk factor for poor linear growth. Am J Phys Anthropol 149:307–311, 2012. © 2012 Wiley Periodicals, Inc. 相似文献
133.
134.
A bursal pentapeptide (BPP-I), a novel bursal-derived peptide, exhibits antiproliferation of tumor cell and immunomodulator activity 总被引:1,自引:0,他引:1
Feng XL Liu QT Cao RB Zhou B Wang FQ Deng WL Qiu YF Zhang Y Ishag H Ma ZY Zheng QS Chen PY 《Amino acids》2012,42(6):2215-2222
The bursa of Fabricius (BF) is the central humoral immune organ unique to birds. Here, we isolated a novel bursal pentapeptide I (BPP-I), LGPGP, from BF. BPP-I could play inhibition effect on MCF-7 but not on CEF or Vero cell proliferation in vitro, and enhance antitumor factor p53 protein expression. Also, BPP-I stimulated antibody production in a dose-dependent manner in hybridoma cell. Furthermore, BPP-I could induce various immune responses in mice immunization experiments, including increase antibody production and cytokines IL-4 and IFN-γ level, and induce T-cell immunophenotyping. These results suggest that BPP-I is a potential immunomodulator of antitumor and immunity. The study could provide some novel insights on the probable candidate reagent for the antitumor and immune improvement. 相似文献
135.
Xiu L. Feng Qing T. Liu Rui B. Cao Bin Zhou De Y. Li Yuan P. Zhang Ke Liu Xiao D. Liu Jian C. Wei Ya F. Qiu Xin F. Li Zhi Y. Ma Pu Y. Chen 《Amino acids》2012,43(6):2443-2456
Bursa of Fabricius is the acknowledged vital humoral immune system for B cell differentiation and antibody production. To study the molecular mechanism underlying the effect of bursal-derived BP5, we used gene microarray to analyze the genomic expression profiling of BP5-treated hybridoma cells. BP5 exhibited an immunomodulatory effect on antibody production in hybridoma cells and induced alterations in the gene expression profiles related to the immune-related biological processes, such as T cell activation and proliferation, B cell activation, B cell-mediated immunity, and cytokines cytokine production involved in immune response. In addition, 26 biological pathways associated with immunomodulatory functions were regulated in BP5-treated hybridoma cells, in which p53 signal pathway played an important role in antitumor. Among these regulated genes, 12 differentially expressed genes were verified by qRT-PCR. The activation of p53 activity by BP5 was further confirmed by p53 luciferase reporter assay and p53 expression. Our data revealed that bursal-derived BP5 could regulate various immune-related cellular processes, including antitumor factor p53 signal pathway, perhaps partially accounting for the reported immunomodulatory roles and novel antiproliferation on tumor cells functions of bursal-derived bioactive factor BP5. 相似文献
136.
Zhang XY Liang J Chen da C Xiu MH He J Cheng W Wu Z Yang FD Haile CN Sun H Lu L Kosten TA Kosten TR 《PloS one》2012,7(2):e30937
The high prevalence of smoking in schizophrenia of European background may be related to smoking's reducing clinical symptoms and medication side effects. Because smoking prevalence and its associations with clinical phenotypes are less well characterized in Chinese than European patients with schizophrenia, we assessed these smoking behaviors using clinician-administered questionnaires and the Fagerstrom Test for Nicotine Dependence (FTND) in 776 Chinese male schizophrenia and 560 control subjects. Patients also were rated on the Positive and Negative Symptom Scale (PANSS), the Simpson and Angus Extrapyramidal Symptom Rating Scale (SAES), and the Abnormal Involuntary Movement Scale (AIMS). We found that the schizophrenia patients had a higher lifetime incidence of smoking (79% vs 63%), were more likely to be heavy smokers (61% vs 31%), and had lower smoking cessation rates (4% vs 9%) (all p<0.0001) than controls. Among the schizophrenia patients smoking prevalence increased with age, with the largest difference from controls in the age cohort of 55-75 years: 75% vs 46% (p<0.0001). Among the schizophrenia smokers 73% started to smoke before the onset of their illness by an average of 7.6 years. The patients with schizophrenia who were current smokers scored significantly lower on the PANSS negative symptom subscore (p<0.005), and on the SAES symptom scale (p<0.04; Bonferroni corrected p>0.05) than the non-smoking patients. These results suggest that Chinese males with schizophrenia smoke more frequently than the general population. Further, smokers with schizophrenia may display fewer negative symptoms and possibly less parkinsonism than non-smokers with schizophrenia. 相似文献
137.
Schizophrenic patients have higher smoking rates than the general population. Studies show that smoking may be a form of self-medication in an attempt to alleviate cognitive deficits in schizophrenic patients of European background. This study examined the relationships between smoking and cognitive deficits in Chinese schizophrenic patients, which have previously received little systemic study. We recruited 580 male chronic patients meeting DSM-IV criteria for schizophrenia and 175 male control subjects who were matched on age and education. The subjects completed a detailed cigarette smoking questionnaire, the Fagerstrom Test for Nicotine Dependence (FTND), and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Patients also were rated on the Positive and Negative Symptom Scale (PANSS), the Simpson and Angus Extrapyramidal Symptom Rating Scale (SAES), and the Abnormal Involuntary Movement Scale (AIMS). All five RBANS subscales except for the Visuospatial/Constructional index showed significantly lower cognitive performance for schizophrenics than normal controls. The schizophrenic smokers scored lower than the schizophrenic non-smokers on the RBANS total score and the Visuospatial/Constructional and Immediate Memory indices. Similarly, the control smokers scored lower than the control non-smokers on the RBANS total score and the Immediate Memory index . Also, the schizophrenic smokers consistently performed the poorest on the cognitive domains of the RBANS. Among the schizophrenic patients, smokers displayed significantly fewer negative symptoms than non-smokers. Using multivariate regression analysis the following variables were independently associated with the RBANS total score: years of education, PANSS negative symptom score, age at schizophrenia onset, and number of hospitalizations. Our results show that smoking is associated with significant cognitive impairment in both schizophrenic patients and normal controls, but the smokers with schizophrenia had a reduced level of negative symptoms, suggesting that the benefits of smoking for those with schizophrenia may be limited to certain aspects of a given clinical phenotype. 相似文献
138.
Jia XQ Cheng HQ Qian X Bian CX Shi ZM Zhang JP Jiang BH Feng ZQ 《Cell biochemistry and biophysics》2012,62(1):237-244
microRNA-199a (miR-199a) is a highly conserved miRNA, always deregulated in numerous human tumors. The results of microarray
analysis indicated that miR-199a was frequently downregulated in hepatocellular carcinoma (HCC). The expression levels of
miR-199a in 11 pairs of matched HCC neoplastic and adjacent non-neoplastic tissues, 5 HCC cell lines and liver cell line L02
were examined by quantitative real-time PCR analysis. We found miR-199a was significantly down-regulated in HCC tissues when
compared with pair-matched adjacent non-tumor tissues. We also found the expression level of miR-199a was also substantially
decreased in several human HCC cell lines including SMMC-7721, BEL-7402, BEL-7701, MHCC97H, and HepG2. To investigate the
role of miR-199a in tumorigenesis, we developed a lentiviral vector for the expression of pre-miR-199a (Lenti-miR-199a). Lenti-miR-199a
inhibited HCC cell proliferation in vitro and in vivo. Compared to parental cells or cells transfected with a control vector,
the overexpression of microRNA-199a in the HCC cell lines HepG2 stably was showed to reduce cell proliferation in vitro and
in vivo. Luciferase reporter assay revealed the regulation of miR-199a on 3’-UTR of HIF-1α. Further investigation confirmed
that miR-199a significantly reduced the endogenous protein level of HIF-1α in hypoxia. MiR-199a inhibits cell proliferation
in vitro and in vivo partly through down-regulation of HIF-1α in human HCC. Thus, these studies provide an important new insight
into the pathogenesis of human HCC and it may open a new perspective for the development of effective gene therapy for human
HCC. 相似文献
139.
X Chen F Xiu CN Horvath D Damjanovic N Thanthrige-Don M Jeyanathan Z Xing 《PloS one》2012,7(7):e41666
Tuberculosis (TB) vaccine-induced airway luminal T cells (ALT) have recently been shown to be critical to host defense against pulmonary TB. However, the mechanisms that maintain memory ALT remain poorly understood. In particular, whether respiratory mucosal exposure to environmental agents such as endotoxin may regulate the size of vaccine-induced ALT population is still unclear. Using a murine model of respiratory genetic TB vaccination and respiratory LPS exposure, we have addressed this issue in the current study. We have found that single or repeated LPS exposure increases the number of antigen-specific ALT which are capable of robust secondary responses to pulmonary mycobacterial challenge. To investigate the potential mechanisms by which LPS exposure modulates the ALT population, we have examined the role of ALT proliferation and peripheral T cell recruitment. We have found that LPS exposure-increased ALT is not dependent on increased ALT proliferation as respiratory LPS exposure does not significantly increase the rate of proliferation of ALT. But rather, we find it to be dependent upon the recruitment of peripheral T cells into the airway lumen as blockade of peripheral T cell supplies markedly reduces the initially increased ALT. Thus, our data suggest that environmental exposure to airborne agents such as endotoxin has a profound modulatory effect on TB vaccine-elicited T cells within the respiratory tract. Our study provides a new, M.tb antigen-independent mechanism by which the respiratory mucosal anti-TB memory T cells may be maintained. 相似文献
140.