全文获取类型
收费全文 | 1104篇 |
免费 | 71篇 |
国内免费 | 2篇 |
出版年
2024年 | 3篇 |
2023年 | 13篇 |
2022年 | 26篇 |
2021年 | 54篇 |
2020年 | 44篇 |
2019年 | 41篇 |
2018年 | 42篇 |
2017年 | 38篇 |
2016年 | 41篇 |
2015年 | 63篇 |
2014年 | 81篇 |
2013年 | 93篇 |
2012年 | 102篇 |
2011年 | 79篇 |
2010年 | 57篇 |
2009年 | 34篇 |
2008年 | 57篇 |
2007年 | 62篇 |
2006年 | 42篇 |
2005年 | 30篇 |
2004年 | 42篇 |
2003年 | 45篇 |
2002年 | 33篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1985年 | 4篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 4篇 |
1980年 | 6篇 |
1978年 | 1篇 |
1976年 | 3篇 |
1967年 | 2篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有1177条查询结果,搜索用时 15 毫秒
51.
Esmail Nourmohammadi Hoda Khoshdel-sarkarizi Reza Nedaeinia Hamid Reza Sadeghnia Leila Hasanzadeh Majid Darroudi Reza Kazemi oskuee 《Journal of cellular physiology》2019,234(4):4987-4996
Cerium oxide nanoparticles are associated with anticancer effects. While protecting normal cells, these nanoparticles exert their anticancer effects via oxidative stress and apoptosis in the cancer cells. In this study, the anticancer properties of nanoceria on fibrosarcoma cell line are evaluated. Cerium oxide nanoparticles were synthesized by the coprecipitation method and their anticancer effects on mouse fibrosarcoma tumor cells (WEHI164) were investigated. Viability assay was evaluated by MTT, and the DC-FDA assay performed for the detection of reactive oxygen species. For apoptosis assay, the annexin V/PI test was done as well as measuring the mRNA and protein expression levels of Bax and Bcl2 by real-time PCR and western blot method, respectively. Characterization of nanoceria reveals that synthesized nanoceria has cubic floruit structure with a size of about 30 nm. Toxicity assessment results show that nanoceria increases ROS levels and induced apoptosis in a dose-dependent manner in cancer cells (WEHI164), whereas low levels of toxicity were observed in normal cells (L929), even at the concentrations above 250 µg/ml in MTT assay. Real-time PCR and western blot assays showed that nanoceria could significantly increase the Bax expression in cancer cells. The results showed that nanoceria could act as a potential therapeutic agent for the treatment of fibrosarcoma. 相似文献
52.
Leila Gholami Mohsen Tafaghodi Bita Abbasi Majid Daroudi Reza Kazemi Oskuee 《Journal of cellular physiology》2019,234(2):1547-1559
Theranostic nanoparticles (NPs) are promising for opening new windows toward personalized disease management. Using a single particle capable of both diagnosis and drug delivery, is the major benefit of such particles. In the present study, chitosan NPs were used as a dual action carrier for doxorubicin (DOX; chemotherapeutic agent) and superparamagnetic iron oxide nanoparticles (SPIONs; imaging agent). SPIONs and DOX were loaded at different concentrations within poly-l -arginine-chitosan-triphosphate matrix (ACSD) using the ionic gelation method. NPs’ size were in the range of 184.33 ± 4.4 nm. Drug release analysis of DOX loaded NPs (NP-DOX) showed burst release at pH 5.5 (as in tumor environment) and slow release at pH 7.4 (physiological condition), demonstrating pH-sensitive drug release profile. NP-DOX internalization was confirmed by flowcytometry and fluorescent microscopy. Uptake process results were corroborated by accumulation of drug in the intracellular space. Iron content was evaluated by inductively coupled plasma and prussian blue staining. In vitro magnetic resonance imaging (MRI) showed a decline in T 2 relaxation times by increasing iron concentration. MRI analysis also confirmed uptake of NPs at the optimum concentration in C6 glioma cells. In conclusion, ACSD NPs could be utilized as a promising theranostic formulation for both diagnosis and treatment of glioblastoma. 相似文献
53.
Davoudi Pahnekolayi Mahboubeh Tehranifar Ali Samiei Leila Shoor Mahmoud 《Plant Cell, Tissue and Organ Culture》2019,137(2):265-274
Plant Cell, Tissue and Organ Culture (PCTOC) - Tissue culture and micrografting techniques are known as effective procedures to produce healthy rose rootstocks and high quality scions. In order to... 相似文献
54.
Leila Roufegarinejad Ryszard Amarowicz 《Journal of biomolecular structure & dynamics》2019,37(11):2766-2775
In the present study, the interaction of Pyrogallol (PG) with human serum albumin (HSA) was investigated by UV, fluorescence, Circular dichroism (CD), and molecular docking methods. The results of fluorescence experiments showed that the quenching of intrinsic fluorescence of HSA by PG was due to a static quenching. The calculated binding constants (K) for PG-HSA at different temperatures were in the order of 104?M ?1, and the corresponding numbers of binding sites, n were approximately equal to unity. The thermodynamic parameters, ΔH and ΔS were calculated to be negative, which indicated that the interaction of PG with HSA was driven mainly by van der Waals forces and hydrogen bonds. The negative value was obtained for ΔG showed that the reaction was spontaneous. In addition, the effect of PG on the secondary structure of HSA was analyzed by performing UV–vis, synchronous fluorescence, and CD experiments. The results indicated that PG induced conformational changes in the structure of HSA. According to Förster no-radiation energy transfer theory, the binding distance of HSA to PG was calculated to be 1.93?nm. The results of molecular docking calculations clarified the binding mode and the binding sites which were in good agreement with the results of experiments.
Communicated by Ramaswamy H. Sarma 相似文献
55.
Sara Jafarzadeh Majid Ahmadi Sanam Dolati Leili Aghebati-Maleki Shadi Eghbal-Fard Amin Kamrani Behboud Behrad Leila Roshangar Farhad Jadidi-Niaragh Bahman Yousefi Mahdi Mehdipour Laya Farzadi Mehdi Yousefi 《Journal of cellular biochemistry》2019,120(4):5424-5434
Exhausted T cells and regulatory T (Treg) cells have been recently proposed to be new risk factors for recurrent miscarriage (RM). Intravenous immunoglobulin G (IVIG) treatment reported to modulate various immune cells. In this study, the effects of IVIG on the frequency and function of exhausted T cells, exhausted Tregs, and Treg cells, as well as pregnancy outcome in women with unexplained RM (URM), were investigated. Ninety-four pregnant women with RM were enrolled. At the time of positive pregnancy, blood samples were drawn. Forty-four patients with URM were included as IVIG receiving treated group and received 400 mg/kg of IVIG and the rest fifty patients were considered as a control group and received no IVIG administration. IVIG was given intravenously every 4 weeks during 32 weeks of gestation. Blood samples of patients were collected after the latest administration. Exhausted T cells, exhausted Tregs, and Treg cells were evaluated pre- and posttreatment in both groups. IVIG induced a significant decrease in the frequency of exhausted Tregs population and function as well as a significant increase in Treg cells population, however, IVIG failed to affect population and the function of exhausted T cells. Pregnancy outcome was successful in IVIG treated women (86.3%) and were significantly different (P = 0.0006) in compared with the untreated URM subjects (42%). Therefore, employing of IVIG increases Treg cells and diminishes exhausted Tregs responses in RM patients with cellular immune anomalies throughout the pregnancy. Immunemodulatory effects of IVIG are probably associated with successful pregnancy outcome. 相似文献
56.
Shirin Kouhpayeh Zahra Hejazi Maryam Boshtam Mina Mirian Ilnaz Rahimmanesh Leila Darzi Abbas Rezaei Laleh Shariati Hossein Khanahmad 《Journal of cellular biochemistry》2019,120(9):16264-16272
One of the most important molecules for multiple sclerosis pathogenesis is α4 integrin, which is responsible for autoreactive leukocytes migration into the brain. The monoclonal antibody, natalizumab, was introduced to market for blocking the extravasation of autoreactive leukocytes via inhibition of α4 integrin. However, the disadvantages of antibodies provided a suitable background for other agents to be replaced with antibodies. Considering the profound advantages of aptamers over antibodies, aptamer isolation against α4 integrin was intended in the current study. The α4 integrin-specific aptamers were selected using cell-systematic evolution of ligands by exponential enrichment (SELEX) method with human embryonic kidney (HEK)-293T overexpressing α4 integrin and HEK-293T as target and control cells, respectively. Evaluation of selected aptamer was performed through flow cytometric analysis. The selected clones were then sequenced and analyzed for any possible secondary structure and affinity. The results of this study led to isolation of 13 different single-stranded DNA clones in 11 rounds of selection which were categorized to three clusters based on common structural motifs and the equilibrium dissociation constant (K d) of the most stable structure was calculated. The evaluation of SELEX progress showed growth in aptamer affinity with increasing of the number of cycles. Taken together, the findings of this study demonstrated the isolation of α4-specific single-stranded DNA aptamers with suitable affinity for ligand, which can further be replaced with natalizumab. 相似文献
57.
58.
Hadi Nedaei Nasrollah Rezaei-Ghaleh Karin Giller Stefan Becker Leila Karami Ali Akbar Moosavi-Movahedi Christian Griesinger Ali Akbar Saboury 《The Journal of biological chemistry》2022,298(3)
Alzheimer''s disease is characterized by the presence of extraneuronal amyloid plaques composed of amyloid-beta (Aβ) fibrillar aggregates in the brains of patients. In mouse models, it has previously been shown that atorvastatin (Ator), a cholesterol-lowering drug, has some reducing effect on the production of cerebral Aβ. A meta-analysis on humans showed moderate effects in the short term but no improvement in the Alzheimer''s Disease Assessment Scale—Cognitive Subscale behavioral test. Here, we explore a potential direct effect of Ator on Aβ42 aggregation. Using NMR-based monomer consumption assays and CD spectroscopy, we observed a promoting effect of Ator in its original form (Ator-calcium) on Aβ42 aggregation, as expected because of the presence of calcium ions. The effect was reversed when applying a CaCO3-based calcium ion scavenging method, which was validated by the aforementioned methods as well as thioflavin-T fluorescence assays and transmission electron microscopy. We found that the aggregation was inhibited significantly when the concentration of calcium-free Ator exceeded that of Aβ by at least a factor of 2. The 1H–15N heteronuclear single quantum correlation and saturation-transfer difference NMR data suggest that calcium-free Ator exerts its effect through interaction with the 16KLVF19 binding site on the Aβ peptide via its aromatic rings as well as hydroxyl and methyl groups. On the other hand, molecular dynamics simulations confirmed that the increasing concentration of Ator is necessary for the inhibition of the conformational transition of Aβ from an α-helix-dominant to a β-sheet-dominant structure. 相似文献
59.
Dodykhudoeva LR 《Collegium antropologicum》2004,28(Z1):147-159
The paper presents a study on the West Pamir communities (Badakhshan, Tajikistan) based on language data of the Pamir languages of East-Iranian origin. At present, the ethnic groups of the West Pamir: Shughni, Rushani, Bartangi, Roshorvi, Khufi, Ishkashimi and Wakhi are communities of the Ismaili Shia Islam faith. The underlying concept of the paper is that ethnic and cultural key-concepts take place in the origin of the traditional beliefs and rituals and can be reliably reconstructed from the vocabulary of a particular community. Pamir languages vocabulary of the Pamir ethnic communities that uses East and West Iranian culturally significant terms may serve as a basis for understanding the genesis of Pamir Ismailism, its particular way of absorbing external cultures, and its present specific form. The purely linguistic criteria, like temporal dimension (linguistic chronology), and geographic dispersion and mobility, are believed to be critical for linking etymology to broader socio-cultural development context of the Pamir communities socio-historical and cultural life. Contemporary social and linguistic dynamics in the relations between nation, religion and language in Tajikistan needs systematic research, and reasonable interpretation. 相似文献
60.
High-level genotypic variation and antibiotic sensitivity among Escherichia coli O157 strains isolated from two Scottish beef cattle farms 总被引:2,自引:0,他引:2
Vali L Wisely KA Pearce MC Turner EJ Knight HI Smith AW Amyes SG 《Applied and environmental microbiology》2004,70(10):5947-5954
Escherichia coli O157:H7 is a human pathogen that is carried and transmitted by cattle. Scotland is known to have one of the highest rates of E. coli O157 human infections in the world. Two hundred ninety-three isolates were obtained from naturally infected cattle and the environment on two farms in the Scottish Highlands. The isolates were typed by pulsed-field gel electrophoresis (PFGE) with XbaI restriction endonuclease enzyme, and 19 different variations in patterns were found. There was considerable genomic diversity within the E. coli O157 population on the two farms. The PFGE pattern of one of the observed subtypes matched exactly with that of a strain obtained from a Scottish patient with hemolytic-uremic syndrome. To examine the stability of an individual E. coli O157 strain, continuous subculturing of a strain was performed 110 times. No variation from the original PFGE pattern was observed. We found three indistinguishable subtypes of E. coli O157 on both study farms, suggesting common sources of infection. We also examined the antibiotic resistance of the isolated strains. Phenotypic studies demonstrated resistance of the strains to sulfamethoxazole (100%), chloramphenicol (3.07%), and at a lower rate, other antibiotics, indicating the preservation of antibiotic sensitivity in a rapidly changing population of E. coli O157. 相似文献