全文获取类型
收费全文 | 314篇 |
免费 | 13篇 |
出版年
2024年 | 1篇 |
2023年 | 8篇 |
2022年 | 10篇 |
2021年 | 22篇 |
2020年 | 8篇 |
2019年 | 13篇 |
2018年 | 12篇 |
2017年 | 19篇 |
2016年 | 12篇 |
2015年 | 19篇 |
2014年 | 24篇 |
2013年 | 29篇 |
2012年 | 18篇 |
2011年 | 20篇 |
2010年 | 17篇 |
2009年 | 9篇 |
2008年 | 19篇 |
2007年 | 10篇 |
2006年 | 9篇 |
2005年 | 14篇 |
2004年 | 3篇 |
2003年 | 1篇 |
2002年 | 4篇 |
2001年 | 3篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1981年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有327条查询结果,搜索用时 15 毫秒
211.
The genus Nanovirus consists of plant viruses that predominantly infect legumes leading to devastating crop losses. Nanoviruses are transmitted by various aphid species. The transmission occurs in a circulative nonpropagative manner. It was long suspected that a virus-encoded helper factor would be needed for successful transmission by aphids. Recently, a helper factor was identified as the nanovirus-encoded nuclear shuttle protein (NSP). The mode of action of NSP is currently unknown in contrast to helper factors from other plant viruses that, for example, facilitate binding of virus particles to receptors within the aphids' stylets. In this review, we are summarizing the current knowledge about nanovirus–aphid vector interactions. 相似文献
212.
213.
Shankargouda Patil Heba Ashi Jagadish Hosmani Abdulrahman Yahya Almalki Yaser Ali Alhazmi Shazia Mushtaq Sameena Parveen Hosam Ali Baeshen Saranya Varadarajan A. Thirumal Raj Vikrant R. Patil Nishant Vyas 《Saudi Journal of Biological Sciences》2021,28(8):4553-4559
BackgroundTinospora cordifolia (Thunb.) Miers (Giloy) has been applied successfully as an anti-inflammatory, anti-diabetic, and even as an anti-cancer agent. Yet, to date, the application of Giloy has not been explored concerning oral cancer.ObjectivesTo assess the effect of T cordifolia (Thunb.) Miers (Giloy) extract (TcE) on an oral cancer cell line.MethodsAW13516 (oral cancer cell line) cells were treated with the prepared aqueous extract of TcE for 24 h at various concentrations ranging between 5 μg/ml and 100 μg/ml and compared with control (cells without treatment). Thee effect of the extracts on apoptosis was assessed by through Annexin V flow cytometry assay and Luminometry based assessment of Caspase 8, 9 and caspase 3/7 activity. RNA was isolated from treated cells and gene expression of selected metastatic genes (MMP1, MMP10, and CXCL8); epithelial-mesenchymal stem cell genes (TWIST1, SNAIL, ZEB1, Oct4) and stemness related genses (Nanog, Sox2) were analyzed by using a quantitative real-time PCR system. The experiments were performed in triplicates.ResultsAqueous extract of TcE was found to induce apoptosis inducer in AW13516 cells in a concentration-dependent manner and was potent even at a low concentration of 5 μg/ml. The apoptosis induction was confirmed with the caspase activity assay. Treatment of the cells with the extract for 24 h exhibited a significant decrease in the expression of EMT genes in a dose-dependent manner without an effect on the metastatic genes.ConclusionAqueous extract of TcE induces apoptosis-mediated cell death in the oral cancer cell line AW13516 while attenuating its potential for epithelial mesenchymal transition. 相似文献
214.
Hydrogenophaga sp. strain PBC is an effective degrader of 4-aminobenzenesulfonate isolated from textile wastewater. Here we present the assembly and annotation of its genome, which may provide further insights into its metabolic potential. This is the first announcement of the draft genome sequence of a strain from the genus Hydrogenophaga. 相似文献
215.
Oliver J. Sabot Alex Mwita Justin M. Cohen Yahya Ipuge Megumi Gordon David Bishop Moses Odhiambo Lorrayne Ward Catherine Goodman 《PloS one》2009,4(9)
Background
WHO estimates that only 3% of fever patients use recommended artemisinin-based combination therapies (ACTs), partly reflecting their high prices in the retail sector from where many patients seek treatment. To overcome this challenge, a global ACT subsidy has been proposed. We tested this proposal through a pilot program in rural Tanzania.Methods/Principal Findings
Three districts were assigned to serve either as a control or to receive the subsidy plus a package of supporting interventions. From October 2007, ACTs were sold at a 90% subsidy through the normal private supply chain to intervention district drug shops. Data were collected at baseline and during intervention using interviews with drug shop customers, retail audits, mystery shoppers, and audits of public and NGO facilities.The proportion of consumers in the intervention districts purchasing ACTs rose from 1% at baseline to 44.2% one year later (p<0.001), and was significantly higher among consumers purchasing for children under 5 than for adults (p = 0.005). No change in ACT usage was observed in the control district. Consumers paid a mean price of $0.58 for ACTs, which did not differ significantly from the price paid for sulphadoxine-pyrimethamine, the most common alternative. Drug shops in population centers were significantly more likely to stock ACTs than those in more remote areas (p<0.001).Conclusions
A subsidy introduced at the top of the private sector supply chain can significantly increase usage of ACTs and reduce their retail price to the level of common monotherapies. Additional interventions may be needed to ensure access to ACTs in remote areas and for poorer individuals who appear to seek treatment at drug shops less frequently.Trial Registration
Controlled-Trials.com ISRCTN39125414. 相似文献216.
TRPC channels are a subset of the transient receptor potential (TRP) proteins widely expressed in mammalian cells. They are thought to be primarily involved in determining calcium or sodium entry and have broad-ranging functions that include regulation of cell proliferation, motility and contraction. The channels do not respond to a single stimulator but rather are activated or modulated by a multiplicity of factors, potentially existing as integrators at the plasma membrane. This review considers the sensitivity of TRPCs to lipid factors, with focus on sensitivities to diacylglycerols, lysophospholipids, arachidonic acid and its metabolites, sphingosine-1-phosphate (S1P), cholesterol and derivatives, and other lipid factors such as gangliosides. Promiscuous and selective lipid-sensing are apparent. In many cases the lipids stimulate channel function or increase insertion of channels in the membrane. Both direct and indirect (receptor-dependent) lipid effects are evident. Although information is limited, the lipid profiles are consistent with TRPCs having close working relationships with phospholipase C and A2 enzymes. We need much more information about lipid-sensing by TRPCs if we are to fully appreciate its significance, but the available data suggest that lipid-sensing is a key, but not exclusive, aspect of TRPC biology. 相似文献
217.
Intratumoral Delivery of Paclitaxel in Solid Tumor from Biodegradable Hyaluronan Nanoparticle Formulations 总被引:1,自引:0,他引:1
Abeer M. Al-Ghananeem Ahmad H. Malkawi Yahya M. Muammer Justin M. Balko Esther P. Black Walid Mourad Edward Romond 《AAPS PharmSciTech》2009,10(2):410-417
In the current study, novel paclitaxel-loaded cross-linked hyaluronan nanoparticles were engineered for the local delivery
of paclitaxel as a prototype drug for cancer therapy. The nanoparticles were prepared using a desolvation method with polymer
cross-linking. In vitro cytotoxicity studies demonstrated that less than 75% of the MDA-MB-231 and ZR-75-1 breast cancer cells were viable after
2-day exposure to paclitaxel-loaded hyaluronan nanoparticles or free paclitaxel, regardless of the dose. These results suggest
that hyaluronan nanoparticles maintain the pharmacological activity of paclitaxel and efficiently deliver it to the cells.
Furthermore, in vivo administration of the drug-loaded nanoparticles via direct intratumoral injection to 7,12-dimethylbenz[a]anthracene (DMBA)-induced
mammary tumor in female rats was studied. The paclitaxel-loaded nanoparticles treated group showed effective inhibition of
tumor growth in all treated rats. Interestingly, there was one case of complete remission of tumor nodule and two cases of
persistent reduction of tumor size that was observed on subsequent days. In the case of free paclitaxel-treated group, the
mean tumor volume increased almost linearly (R
2 = 0.93) with time to a size that was 4.9-fold larger than the baseline volume at 57 days post-drug administration. Intratumoral
administration of paclitaxel-loaded hyaluronan nanoparticles could be a promising treatment modality for solid mammary tumors. 相似文献
218.
Enzymatic synthesis of palm-based ascorbyl esters 总被引:2,自引:0,他引:2
Hamidah Burham Raizatul Ainaa Gafoor Abdul Rasheed Noorullhamezon Md. Noor Suzaini Badruddin Hamidah Sidek 《Journal of Molecular Catalysis .B, Enzymatic》2009,58(1-4):153-157
The synthesis of palm-based ascorbyl esters through transesterification of ascorbic acid and palm oil in tert-amyl alcohol catalyzed by immobilized lipase is described. Highest conversion (70–75%) was determined after 16 h reaction at 40 °C using lipase (Novozyme 435 from Candida antartica) with an ascorbic acid to palm oil mole ratio of 1:8. The purified product was further characterized by 13C NMR and GC–MS and the mixture of ascorbyl monoesters obtained were identified as ascorbyl monooleate (61%), ascorbyl monopalmitate (30%) and ascorbyl monostearate (9%). The antioxidant activity of palm-based ascorbyl esters was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) test. The results showed that pure palm-based ascorbyl esters have an antioxidant activity with an IC50 value of 0.1 mg/mL. 相似文献
219.
Diana Martínez-Redondo Ana Marcuello José A. Casajús Ignacio Ara Yahya Dahmani Julio Montoya Eduardo Ruiz-Pesini Manuel J. López-Pérez Carmen Díez-Sánchez 《Mitochondrion》2010,10(2):102-107
Mitochondrial background has been demonstrated to influence maximal oxygen uptake (VO2max, in mL kg?1 min?1), but this genetic influence can be compensated for by regular exercise. A positive correlation among electron transport chain (ETC) coupling, ATP and reactive oxygen species (ROS) production has been established, and mitochondrial variants have been reported to show differences in their ETC performance. In this study, we examined in detail the VO2max differences found among mitochondrial haplogroups. We recruited 81 healthy male Spanish Caucasian individuals and determined their mitochondrial haplogroup. Their VO2max was determined using incremental cycling exercise (ICE). VO2max was lower in J than in non-J haplogroup individuals (P = 0.04). The H haplogroup was responsible for this difference (VO2max; J vs. H; P = 0.008) and this group also had significantly higher mitochondrial oxidative damage (mtOD) than the J haplogroup (P = 0.04). In agreement with these results, VO2max and mtOD were positively correlated (P = 0.01). Given that ROS production is the major contributor to mtOD and consumes four times more oxygen per electron than the ETC, our results strongly suggest that ROS production is responsible for the higher VO2max found in the H variant. These findings not only contribute to a better understanding of the mechanisms underneath VO2max, but also help to explain some reported associations between mitochondrial haplogroups and mtOD with longevity, sperm motility, premature aging and susceptibility to different pathologies. 相似文献
220.
Paul E. Simonsen Erling M. Pedersen Rwehumbiza T. Rwegoshora Mwelecele N. Malecela Yahya A. Derua Stephen M. Magesa 《PLoS neglected tropical diseases》2010,4(6)