全文获取类型
收费全文 | 8006篇 |
免费 | 514篇 |
国内免费 | 50篇 |
专业分类
耳鼻咽喉 | 120篇 |
儿科学 | 171篇 |
妇产科学 | 127篇 |
基础医学 | 971篇 |
口腔科学 | 270篇 |
临床医学 | 679篇 |
内科学 | 1685篇 |
皮肤病学 | 165篇 |
神经病学 | 516篇 |
特种医学 | 315篇 |
外国民族医学 | 2篇 |
外科学 | 1252篇 |
综合类 | 136篇 |
一般理论 | 5篇 |
预防医学 | 548篇 |
眼科学 | 362篇 |
药学 | 731篇 |
中国医学 | 73篇 |
肿瘤学 | 442篇 |
出版年
2024年 | 9篇 |
2023年 | 100篇 |
2022年 | 203篇 |
2021年 | 378篇 |
2020年 | 249篇 |
2019年 | 315篇 |
2018年 | 403篇 |
2017年 | 270篇 |
2016年 | 329篇 |
2015年 | 319篇 |
2014年 | 469篇 |
2013年 | 571篇 |
2012年 | 800篇 |
2011年 | 793篇 |
2010年 | 461篇 |
2009年 | 324篇 |
2008年 | 513篇 |
2007年 | 474篇 |
2006年 | 363篇 |
2005年 | 297篇 |
2004年 | 224篇 |
2003年 | 232篇 |
2002年 | 176篇 |
2001年 | 34篇 |
2000年 | 24篇 |
1999年 | 34篇 |
1998年 | 24篇 |
1997年 | 13篇 |
1996年 | 17篇 |
1995年 | 13篇 |
1994年 | 12篇 |
1993年 | 12篇 |
1992年 | 4篇 |
1991年 | 9篇 |
1990年 | 4篇 |
1989年 | 11篇 |
1988年 | 11篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1982年 | 8篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1978年 | 7篇 |
1977年 | 5篇 |
1976年 | 8篇 |
1975年 | 9篇 |
1974年 | 6篇 |
排序方式: 共有8570条查询结果,搜索用时 15 毫秒
91.
Nafise Tabasi Mahmoud Mahmoudi Maryam Rastin Hamid Reza Sadeghnia Mojtaba HosseinPour Mashhadi Shahrzad Zamani Taghizade Rabe 《Food and Agricultural Immunology》2015,26(1):138-156
Renal cell carcinoma (RCC) is the most common renal malignancy in adults and exhibits highly intrinsic and acquired resistance to standard therapeutic strategies. We sought to determine the anti-cancer activity of hydroalcoholic extract of Nigella sativa seeds (NSE) and thymoquinone (TQ). Human renal cell carcinoma (ACHN) and fibroblast L929 cell lines were treated with NSE and TQ, and cytotoxicity was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium (MTT) assay. Cell death pattern was determined by annexin V and propidium iodine (PI)-staining methods. Exposure to NSE, TQ and cisplatin significantly inhibited the growth of ACHN cells and showed significant increase of early apoptotic cells. Normal cells were more resistant to NSE and TQ-induced effects. The present study demonstrates that N. sativa and TQ exert anti-proliferative and pro-apoptotic effects on ACHN cells in a concentration and time-dependent manner, which suggests their potential to be used as a new therapeutic strategy for renal cancers. 相似文献
92.
María Elena Contreras Campos Nora Rodríguez‐Cervantes Sandra Reza‐López Marina Ávila‐Esparza Dora Virginia Chávez‐Corral Margarita Levario‐Carrillo 《Maternal & child nutrition》2015,11(2):164-172
Teenage pregnancy has been associated with adverse effects for the mother and the newborn (NB). In order to compare body composition (BC) between adolescents (Ad) and mature women (MW) during pregnancy and to determine the difference in birthweight and perinatal morbidity, pregnant Ad (n = 40) and MW (n = 227) were studied. BC changes between the second and third trimesters were determined by multifrequency bioelectrical impedance analysis, and birthweight and NB morbidity were evaluated. During the second and third trimesters of the pregnancy, fat mass was lower in the Ad group [16 kg (13–19)] than in the MW group [22 kg (17–27)] (P < 0.01; median and quartiles 1–3). Fat‐free mass increased by 3.09 kg (2.29–4.20) and 2.20 kg (1.0–3.59) (P ≤ 0.01), and total body water increased by 2.77 L (0.84–4.49) vs. 2.04 L (0.55–3.89) (P = 0.36), in the Ad and MW groups, respectively (median and quartiles 1–3). Birthweight was not significantly different between NBs of Ad (3223 ± 399 g) and NBs of MW (3312 ± 427 g, P = 0.22). The youngest Ad (<18 year old, n = 8) had NB with lower birthweight than MW (3031 ± 503 g, P = 0.06). NBs of Ad mothers showed a non‐significant trend towards a higher rate of morbidity relative to the NBs of MW. In conclusion, the BC of Ad differs from that of MW during pregnancy. In addition, the NB infants of Ad mothers tended to have a lower birthweight than those from MW, a result that suggests that the Ad should be in strict prenatal control. 相似文献
93.
Radiologic resolution of malignant infantile osteopetrosis skeletal changes following hematopoietic stem cell transplantation 下载免费PDF全文
94.
Purpose
The evidence has suggested that resveratrol has anti-inflammatory effect; however, the results are inconsistent and inconclusive. The aim of this study was to assess the effect of resveratrol supplementation on the levels of inflammatory markers through a systematic review and meta-analysis of available randomized controlled trials (RCTs).Methods
A search strategy was completed using Medline, ISI Web of Science, Directory of Open Access Journal, SID, ProQuest, Cochrane Library, Scopus, and EMBASE up to May 2017, to identify placebo-controlled RCTs that assessed resveratrol effects on circulating (serum and plasma) inflammatory markers (interleukin [IL]-6, tumor necrosis factor–α [TNF-α], and high-sensitivity C-reactive protein [hs-CRP]) among adult participants aged 17 years and older in 17 RCTs with a total of 736 subjects. The evaluation of study quality was performed using the Jadad scale. Weighted mean difference (WMD) was calculated for evaluating the changes in the inflammatory markers using fixed-effects or random-effects models. We performed subgroup and sensitivity analyses to evaluate the heterogeneity of the studies.Findings
Seventeen RCTs, including 736 subjects, fulfilled the eligibility criteria and were selected for analyses. The results of meta-analysis found significant reductions in the level of TNF-α (WMD, –0.44; 95% CI, –0.71 to –0.164; P?=?0.002; Q statistic?=?21.60; I2?=?49.1%; P?=?0.02) and hs-CRP (WMD, –0.27; 95% CI, –0.5 to –0.02; P?=?0.033; Q statistic?=?26.95; I2?=?51.8%; P?=?0.013) after supplementation with resveratrol. Resveratrol supplementation had no significant effect on the level of IL-6 (WMD, –0.16; 95% CI, –0.53 to 0.20; P?=?0.38; Q statistic?=?36.0; I2?=?72.3%; P?=?0.001). Statistically significant heterogeneity was observed for the type of sample in IL-6 and study duration in inflammatory markers IL-6, TNF-α, and hs-CRP.Implications
Available evidence from RCTs suggests that resveratrol supplementation significantly reduced TNF-α and hs-CRP levels. Significant improvement in inflammatory markers support resveratrol as an adjunct to pharmacologic management of metabolic diseases. 相似文献95.
Hamed?AghajaniEmail author Mohammad?Reza?Marvie Mohadjer Ehsan?Bari Katie?M.?Ohno Anoushirvan?Shirvany Mohamad?Reza?Asef 《Proceedings of the National Academy of Sciences, India. Section B.》2018,88(4):1463-1469
Fungal diversity in the Hyrcanian forests can greatly vary due to diverse ecological conditions. The scope of the present research was to investigate the diversity of wood decay fungi at three sites in the northern forests of Iran. Fruiting bodies of fungi were collected in three plots dominated by Quercus castaneifolia C.A.M. (oak) and Carpinus betulus L. (hornbeam) in the Hyrcanian Forest. As many as 19 and 13 taxa were found on hornbeam and oak, respectively. The identification of these fungi revealed Fomes fomentarius (L.) Fr. and Ganoderma lucidum (Curtis) P. Karst. as highly abundant on hornbeam and oak, respectively. Highest fungal abundance was observed at an altitude range of 1150-1200 meters above sea level. Diversity of macro-fungi was determined and the mean Shannon diversity index was found to be 2.52 and 1.94 for hornbeam and oak, respectively, and mean equitability was calculated as 0.84 and 0.73 for hornbeam and oak, respectively. There were no significant differences in the Shannon Diversity Index or equitability. Overall, current work showed that most of the identified fungi were classified as white rot fungi. 相似文献
96.
Ata Farajzadeh Saman Maroufizadeh Hamid Reza Rostami Amir Hassan Kohan 《Disability and rehabilitation》2018,40(3):367-372
Purpose: To investigate the psychometric properties of the Persian version of Caregiver Burden Scale (CBS) in caregivers of patients with spinal cord injury.Methods: This is a cross-sectional study. After a forward–backward translation, the CBS was administered to 110 caregivers of patients with spinal cord injury (men?=?60, women?=?50). Factor structure was evaluated by confirmatory factor analysis. The Internal consistency and test–retest reliability of the CBS were examined using Cronbach’s α and the intraclass correlation coefficient, respectively. Construct validity was assessed by examining the relationship among CBS and the World Health Organization Quality of Life, and the Beck Depression Inventory.Results: The results of confirmatory factor analysis provided support for a five-factor model of CBS. All subscales of CBS revealed acceptable internal consistency (0.698–0.755), except for environment subscale (0.559). The CBS showed adequate test–retest reliability for its subscales (0.745–0.900). All subscales of CBS significantly correlated with both Beck Depression Inventory and World Health Organization Quality of Life, confirming construct validity.Conclusions: The Persian version of the CBS is a valid and reliable measure for assessing burden of care in caregivers of patients with spinal cord injury.
- Implications for Rehabilitation
Spinal cord injury leads to depression, high levels of stress and diminished quality of life due to the high physical, emotional, and social burdens in caregivers.
Persian version of the Caregiver Burden Scale is a valid and reliable tool for assessing burden in Iranian caregivers of patients with spinal cord injury.
97.
98.
Mohammad YAKHCHALI Reza MALEKZADEH-VIAYEH Abbas IMANI-BARAN Karim MARDANI 《Iranian Journal of Parasitology》2015,10(1):46-55
Background:
The trematodes of the genus Fasciola (the liver flukes) are among the well-known instances of food-borne parasites worldwide. Differentiation of Fasciola species is important because of their different transmission and epidemiological characteristics. The current study was undertaken to discriminate Fasciola species in the domestic ruminants of Urmia city, Iran.Methods:
Adult flukes were isolated from the naturally infected livers of the slaughtered water buffaloes and sheep. The flukes were initially identified based on morphological and morphometric parameters. A 618-bp-long fragment of the 28SrRNA gene of Fasciola was amplified by polymerase chain reaction (PCR). The amplified fragment was digested by DraII or AvaII enzymes for a restriction fragment length polymorphism (RFLP) analysis and sequenced for the phylogenetic tree construction.Results:
Based on the morphometric examination, the flukes belonged to F. hepatica, F. gigantica and an intermediate Fasciola form. The PCR-RFLP analysis was able to differentiate F. hepatica from F. gigantica. While the phylogenetic reconstruction justified, to some extent, the morphological diagnosis, it failed to segregate F. hepatica from F. gigantica identified in this and the previous studies.Conclusion:
To resolve fully the problem of taxonomy and evolution in Fasciola species, employing a broad range of molecular and morphological approaches is necessary. This is crucial for epidemiological surveys and successful clinical management of their infection. 相似文献99.
Mohsen Tabasi Mohammad Reza Asadi Karam Mehri Habibi Mir Saeed Yekaninejad Saeid Bouzari 《Osong Public Health and Research Perspectives》2015,6(4):261-268
Objectives
Urinary tract infection caused by uropathogenic Escherichia coli (UPEC) strains is one of the most important infections in the world. UPEC encode widespread virulence factors closely related with pathogenesis of the bacteria. The purpose of this study was to evaluate the presence of different phenotypic virulence markers in UPEC isolates and determine their correlation with antibiotic resistance pattern.Methods
UPEC isolates from patients with different clinical symptoms of UTI were collected and screened for biofilm and hemolysin production, mannose resistant, and mannose sensitive hemagglutination (MRHA and MSHA, respectively). In addition, antimicrobial resistance pattern and ESBL-producing isolates were recorded.Results
Of the 156 UPEC isolates, biofilm and hemolysin formation was seen in 133 (85.3%) and 53 (34%) isolates, respectively. Moreover, 98 (62.8%) and 58 (37.2%) isolates showed the presence of Types 1 fimbriae (MSHA) and P fimbriae (MRHA), respectively. Our results also showed a relationship between biofilm formation in UPEC isolated from acute cystitis patients and recurrent UTI cases. Occurrence of UTI was dramatically correlated with the patients'' profiles. We observed that the difference in antimicrobial susceptibilities of the biofilm and nonbiofilm former isolates was statistically significant. The UPEC isolates showed the highest resistance to ampicillin, tetracycline, amoxicillin, and cotrimoxazole. Moreover, 26.9% of isolates were ESBL producers.Conclusion
This study indicated that there is a relationship between the phenotypic virulence traits of the UPEC isolates, patients'' profiles, and antibiotic resistance. Detection of the phenotypic virulence factors could help to improve understanding of pathogenesis of UPEC isolates and better medical intervention. 相似文献100.
Reza Heidari Akram Jamshidzadeh Nahid Keshavarz Negar Azarpira 《Scientia pharmaceutica》2015,83(1):143-158
Methimazole is the most widely prescribed antithyroid medication in humans. However, hepatotoxicity is a deleterious adverse effect associated with methimazole administration. No specific protective agent has been developed against this complication yet. This study was designed to investigate the role of taurine as a hepatoprotective agent against methimazole-induced liver injury in mice. Different reactive metabolites were proposed to be responsible for methimazole hepatotoxicity. Hence, methimazole-induced liver injury was investigated in intact and/or enzyme-induced animals in the current investigation. Animals were treated with methimazole (200 mg/kg, by gavage), and hepatic injury induced by this drug was investigated in intact and/or enzyme-induced groups. Markers such as lipid peroxidation, hepatic glutathione content, alanine aminotransferase (ALT) and alkaline phosphatase (ALP) in plasma, and histopathological changes in the liver of animals were monitored after drug administration. Methimazole caused liver injury as revealed by increased plasma ALT. Furthermore, a significant amount of lipid peroxidation was detected in the drug-treated animals, and hepatic glutathione reservoirs were depleted. Methimazole-induced hepatotoxicity was more severe in enzyme-induced mice. The above-mentioned alterations in hepatotoxicity markers were endorsed by significant histopathological changes in the liver. Taurine administration (1 g/kg, i.p.) effectively alleviated methimazole-induced liver injury in both intact and/or enzyme-induced animals. 相似文献