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491.
This study examined the effect of including one of two growth factors (100 ng/ml IGF-1 or 20 ng/ml EGF) in combination with one of two antioxidants (50 microM cysteamine or 50 microM beta-mercaptoethanol) in maturation, fertilization and subsequent development of buffalo oocytes. The oocytes were recovered by in vivo ovum pick-up technique from six Murrah buffalo heifers twice a week over a period of 16 weeks. Immediately after ovum pick-up oocytes recovered from six donors were allocated randomly to five different maturation treatments. The control treatment was the basic maturation medium (MM; TCM-199 supplemented with 10% FBS, 10 IU/ml LH, 0.5 microg/ml FSH, 1 microg/ml estradiol-17beta and 50 microg/ml gentamicin). The other four treatments consisted of the control maturation medium (MM) plus one combination of a growth factor and an antioxidant viz. IGF-1+cysteamine; IGF-1+beta-ME; EGF+cysteamine or EGF+beta-ME. The total number of oocytes assigned to each maturation treatment ranged from 31 to 66. After maturation in different maturation medium, media used for in vitro fertilization and subsequent development of embryo was same for all groups. Data were analysed using Chi-square test. The maturation rate observed for the growth factor plus antioxidant treatments was similar to that for the control (90.4%). The highest cleavage rate recorded in the IGF-1+cysteamine treatment (71.9%) which was significantly higher (P<0.05) than the IGF-1+beta-ME (45.2%) and EGF+beta-ME (46.4%) treatments, but not significantly differ from the control (63.8%) and EGF+cysteamine treatment (60.7%). The proportion of cleaved oocytes those developed to blastocyst stage was significantly higher in the IGF-1+cysteamine treatment (52.2%; P<0.05) than in the control (23.3%), the EGF+cysteamine (13.5%) or the EGF+beta-ME (7.7%) treatments, but did not differ significantly from the IGF-1+beta-ME (28.6%) treatment. Following non-surgical transfer of 15 embryos to 14 synchronized recipients, four became pregnant and only one recipient sustained the pregnancy as long as 4.5 months when spontaneous abortion occurred. It was concluded that supplementing the maturation medium with IGF-1+cysteamine improved the production of buffalo embryos significantly in vitro culture. 相似文献
492.
Hatem A. Azim Jr Sandeep Singhal Michail Ignatiadis Christine Desmedt Debora Fumagalli Isabelle Veys Denis Larsimont Martine Piccart Stefan Michiels Christos Sotiriou 《PloS one》2013,8(4)
Introduction
SPARC is an important regulator of the extracellular matrix and has been suggested to improve delivery of albumin-bound cytotoxics. However, little is known regarding its role in breast cancer (BC).Methods
We conducted a pooled analysis of publically available datasets, in which BC patients who received no systemic therapy or received neoadjuvant chemotherapy were eligible. Patients were assigned to molecular subtypes using PAM-50. We computed a SPARC module (SPARC7), composed of genes with an absolute correlation with SPARC >0.7. In the systemically untreated cohort, we evaluated 1) expression of SPARC/SPARC7 according to breast cancer subtype, 2) association between SPARC/SPARC7 and biological processes related to proliferation, immune and stroma, and 3) association between SPARC/SPARC7 and relapse-free survival in a Cox model in all patients and in the different molecular subtypes adjusted for tumor size, nodal status, histological grade, and age. In the neoadjuvant cohort, we evaluated the association between SPARC and pCR in a logistic regression model, adjusted for the same clinicopathologic factors.Results
948 (10 datasets), and 791 (8 datasets) patients were included in the systemically untreated and neoadjuvant cohorts, respectively. High SPARC expression was associated with small tumor size, low histological grade and luminal-A tumors (all p<0.0001). There was a positive correlation between SPARC and stroma-related modules but negative correlation with proliferation modules. High SPARC expression was associated with poor prognosis in patients with basal and HER2+ breast cancer even after adjusting for clinicopathologic parameters. In the neoadjuvant cohort, a subgroup analysis suggested that high SPARC is associated with low rates of pCR in the HER2 subtype. Same results were observed on replacing SPARC by SPARC7.Conclusion
This analysis suggests a potential role of SPARC in determining prognosis and response to primary chemotherapy in early BC. This information could guide further development of albumin-bound cytotoxics in BC. 相似文献493.
Sonia Singhal 《Evolution; international journal of organic evolution》2020,74(1):207-209
For bacteria growing in colonies, spatial structure can allow maintenance of costly traits such as the production of antibiotics. Using spatially structured environments, Westhoff et al. examined the benefits of streptomycin production for the bacterium Streptomyces griseus in competition with a streptomycin-susceptible strain. Streptomyces griseus outcompeted susceptible competitors, but the benefit of its antibiotic decreased as competitor resistance to streptomycin increased. Spatial structure also increased the ability of S. griseus to invade susceptible competitor populations from low starting densities. These results demonstrate that spatially structured environments can both provide and amplify benefits of antibiotics to antibiotic-producing bacteria on a microbial scale. 相似文献
494.
Sharad S. Singhal David Horne Jyotsana Singhal Sanjay Awasthi Ravi Salgia 《生物化学与生物物理学报:癌评论》2021,1875(2):188512
Aberrations in RLIP, p53, and PKCα represent essentially the entire spectrum of all human neoplasms. Elevated PKCα expression, failure of the cell cycle checkpoint (p53 dysfunction), and abnormal glutathione (GSH) metabolism are fundamental hallmarks of carcinogenesis and drug/radiation resistance. However, a lack of investigations into the interactions between these important regulatory nodes has fundamentally limited our understanding of carcinogenesis and the development of effective interventions for cancer prevention and therapy. Loss of p53, perhaps the most powerful tumor suppressor gene, predisposes rodents to spontaneous cancer and humans to familial, as well as acquired, cancers. Until recently, no genetic manipulation of any oncogene had been reported to abrogate spontaneous carcinogenesis in p53?/? rodent models. However, the overexpression of RLIP, a GSH-electrophile conjugate (GS-E) transporter, has been found to enhance cancer cell proliferation and confer drug/radiation resistance, whereas its depletion causes tumor regression, suggesting its importance in cancer and drug/radiation resistance. Indeed, RLIP is an essential effector of p53 that is necessary for broad cancer-promoting epigenetic remodeling. Interestingly, through a haploinsufficiency mechanism, the partial depletion of RLIP in p53?/? mice provides complete protection from neoplasia. Furthermore, RLIP?/? mice exhibit altered p53 and PKCα function, marked deficiency in clathrin-dependent endocytosis (CDE), and almost total resistance to chemical carcinogenesis. Based on these findings, in this review, we present a novel and radical hypothesis that expands our understanding of the highly significant cross-talk between p53, PKCα, and GSH signaling by RLIP in multiple tumor models. 相似文献
495.
Studies on boondi, a deep fried batter based legume snack food popular in the Indian sub-continent were conducted to reduce oil content. Effects of varying the water levels in the batter on the shape of the resulting boondi were noted. The effects of incorporating carboxymethyl cellulose (CMC) and hydro-xypropylmethyl cellulose (HPMC) in the bengal gram flour on the water levels so as to get appropriate batter viscosity for getting round shaped boondi were also recorded. The addition of 2% CMC and 1% HPMC (based on weight of bengal gram flour) in the dough decreased oil content in the fried boondi by 26.2% and 22.7% respectively as compared to the control. 相似文献
496.
497.
Hidden persistent malware in guest virtual machine instances are among the most common internal threats in cloud computing, affecting the security of both cloud customers and providers. With the growing sophistication of modern malware, traditional methods are becoming increasingly ineffective for tackling cloud security problems. Moreover, given the pay-per-use model of clouds, consumption of resources by these malwares and malicious services can cause huge losses to both the cloud provider and customer. Thus, it is important to develop mechanisms that can limit the scale of malicious attacks in order to minimize their resources consumption. Trust management is a fundamental technique for assessing and increasing the reliability and security of cloud services. Unfortunately, majority of existing mechanisms for trust management in clouds have limitations that prevent them from being fully effective. In this paper, we propose a novel limited-trust capacity model to mitigate the threats of internal malicious software and services in cloud computing using concepts from flow networks to reduce the scale of malicious software or services. Our limited-trust capacity model can be utilized in the following two ways: (1) to manage the trust relationship among the guest services and to evaluate the threats of unknown malicious services, and (2) to minimize risk associated with renting cloud services and limiting the resource drain caused by malicious guest services. Finally, experimental results show that our limited-trust capacity model can effectively restrict the scale of malicious services and significantly mitigate the threats of internal attacks. 相似文献
498.
499.
Specific inhibition of DNA polymerase beta by its 14 kDa domain: role of single- and double-stranded DNA binding and 5'-phosphate recognition. 总被引:2,自引:1,他引:1 下载免费PDF全文
I Husain B S Morton W A Beard R K Singhal R Prasad S H Wilson J M Besterman 《Nucleic acids research》1995,23(9):1597-1603
DNA polymerase beta (beta-polymerase) has been implicated in short-patch DNA synthesis in the DNA repair pathway known as base excision repair. The native 39 kDa enzyme is organized into four structurally and functionally distinct domains. In an effort to examine this enzyme as a potential therapeutic target, we analyzed the effect of various beta-polymerase domains on the activity of the enzyme in vitro. We show that the 14 kDa N-terminal segment of beta-polymerase, which binds to both single- and double-stranded DNA, but lacks DNA polymerase activity, inhibits beta-polymerase activity in vitro. Most importantly, the 8, 27 and 31 kDa domains of beta-polymerase do not inhibit beta-polymerase activity, demonstrating that the inhibition by the 14 kDa domain is specific. The inhibition of beta-polymerase activity in vitro is abolished by increasing the concentrations of both of the substrates (template-primer and deoxynucleoside triphosphate). In contrast, an in vitro base excision repair assay is inhibited in a domain specific manner by the 14 kDa domain even in the presence of saturating substrates. The inhibition of beta-polymerase activity by the 14 kDa domain appears specific to beta-polymerase as this domain does not inhibit either mammalian DNA polymerase alpha or Escherichia coli polymerase I (Klenow fragment). These data suggest that the 14 kDa domain could be used as a potential inhibitor of intracellular beta-polymerase and that it may provide a means for sensitizing cells to therapeutically relevant DNA damaging agents. 相似文献
500.
Ashok Kumar Singhal Pritish Kumar Chowdhury Ram Prakash Sharma Jogendra Nath Baruah Werner Herz 《Phytochemistry》1982,21(2):462-463
Cynaropicrin and 11,13-dihydrodesacylcynaropicrin were isolated from Tricholepis glaberrima. 相似文献