全文获取类型
收费全文 | 2034篇 |
免费 | 96篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 33篇 |
儿科学 | 70篇 |
妇产科学 | 43篇 |
基础医学 | 210篇 |
口腔科学 | 25篇 |
临床医学 | 199篇 |
内科学 | 425篇 |
皮肤病学 | 26篇 |
神经病学 | 110篇 |
特种医学 | 33篇 |
外国民族医学 | 2篇 |
外科学 | 368篇 |
综合类 | 45篇 |
预防医学 | 107篇 |
眼科学 | 172篇 |
药学 | 109篇 |
中国医学 | 11篇 |
肿瘤学 | 149篇 |
出版年
2023年 | 12篇 |
2022年 | 47篇 |
2021年 | 83篇 |
2020年 | 43篇 |
2019年 | 60篇 |
2018年 | 68篇 |
2017年 | 53篇 |
2016年 | 62篇 |
2015年 | 71篇 |
2014年 | 84篇 |
2013年 | 144篇 |
2012年 | 194篇 |
2011年 | 161篇 |
2010年 | 81篇 |
2009年 | 76篇 |
2008年 | 128篇 |
2007年 | 149篇 |
2006年 | 139篇 |
2005年 | 116篇 |
2004年 | 104篇 |
2003年 | 68篇 |
2002年 | 53篇 |
2001年 | 13篇 |
2000年 | 12篇 |
1999年 | 18篇 |
1998年 | 11篇 |
1997年 | 8篇 |
1996年 | 12篇 |
1995年 | 7篇 |
1992年 | 6篇 |
1991年 | 8篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 6篇 |
1983年 | 3篇 |
1980年 | 2篇 |
1979年 | 5篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1971年 | 2篇 |
1968年 | 3篇 |
1967年 | 3篇 |
1965年 | 1篇 |
1962年 | 1篇 |
1955年 | 1篇 |
1924年 | 1篇 |
排序方式: 共有2137条查询结果,搜索用时 484 毫秒
71.
Sedat Batmaz Semra Ulusoy Kaymak Arif Haldun Soygur Elvan Ozalp Mehmet Hakan Turkcapar 《Comprehensive psychiatry》2013
Background
There is very limited data about the cognitive structure of bipolar depression when compared to unipolar depression. The aim of the study was to look into the differences between unipolar and bipolar depressed patients regarding their cognitive structure in view of Beck's cognitive theory.Methods
In this study, 70 bipolar patients during a depressive episode, 189 unipolar depressed patients and 120 healthy subjects were recruited. The participants were interviewed by using a structured clinical diagnostic scale. To evaluate the cognitive structure differences, the Automatic Thoughts Questionnaire (ATQ) and the Dysfunctional Attitude Scale (DAS) were used.Results
We found that on the mean ATQ total score, the unipolar depressed patients scored significantly higher (92.9 ± 22.7) than both the bipolar depressed patients (73.2 ± 24.7) and the healthy subjects (47.1 ± 19.6), even after controlling for all confounding factors, e.g. gender, marital status, depressive symptom severity (F = 157.872, p < 0.001). The bipolar depressed patients also scored significantly higher on the mean ATQ total score than the healthy controls. On the mean DAS total score, and on the mean score of its subscale of need for approval, the bipolar depressed patients scored (152.8 ± 21.2 and 48.2 ± 7.4, respectively) significantly higher than both the unipolar depressed patients (160.9 ± 29.0 and 51.9 ± 9.7, respectively) and the healthy subjects (127.9 ± 32.8 and 40.2 ± 12.2, respectively), even after controlling for any confounding factor (F = 45.803 [p < 0.001] and F = 43.206 [p < 0.001], respectively). On the mean score of the perfectionistic attitude subscale of the DAS, the depressed groups scored significantly higher than the healthy subjects, but they did not seem to separate from each other (F = 41.599, p < 0.001).Conclusions
These results may help enhance the understanding of the potentially unique psychotherapeutic targets and the underlying cognitive theory of bipolar depression. 相似文献72.
Shin-ichi Tokushige Tomohiro Sonoo Risa Maekawa Yuichiro Shirota Ritsuko Hanajima Yasuo Terao Hideyuki Matsumoto Mohammad Arif Hossain Norio Sakai Yasushi Shiio 《Brain & development》2013
This report describes a 60-year-old female patient with Krabbe disease who presented with slowly progressive gait disturbance due to mild spastic paraplegia. Brain magnetic resonance imaging showed high-intensity lesions along the upper parts of the bilateral pyramidal tracts in fluid-attenuated inversion recovery images. Central motor conduction time was prolonged both in the upper and the lower extremities, while central sensory conduction time was normal. The reduced lymphocyte galactocerebrosidase (GALC) activity and two novel mutations in the GALC gene, p.G496S and p.G569S, proved the diagnosis of Krabbe disease. Our findings show that adult-onset Krabbe disease is characterized by isolated pyramidal tract impairment in the central nervous system, both neurophysiologically and radiologically. 相似文献
73.
Tayyaba Anwar Humaira Nadeem Sadia Sarwar Humaira Naureen Safia Ahmed ArifUllah Khan Muazzam Arif 《Drug development research》2020,81(7):893-903
A series of new isoxazolone ( 3a – d ) and pyrazolone ( 4a – d ) derivatives were synthesized and assessed for their antioxidant and analgesic activity. Among synthesized compounds, 3b and 4b having nitro (NO2) group show high analgesic activity at a dose of 6 mg/kg. Analgesic activity was further proceeded to explore the contribution of opioidergic mechanisms in the mediation of analgesic effects. Animals were administered with naloxone, a nonselective opioid inverse agonist, at the dose of 0.5 mg/kg. The results obtained suggested that the analgesic effects of the synthesized compounds were not reversed by naloxone, specifying that the compounds 3b and 4b do not follow the opioidergic pathway in order to relieve pain in animal models. Further, the binding interactions of compounds 3b and 4b were analyzed by docking them against nonopioid receptors COX-1 (3N8X) and COX-2 (3LN1). The results demonstrate the analgesic potential of isoxazolone and pyrazolone derivatives, especially compounds 3b and 4b can be considered promising lead molecules for further investigation and development into potent analgesic drugs. In addition, the antioxidant potential of compounds was also found to be related to better analgesic activity, thus providing an insight into the role of oxidative stress in the mediation of analgesia. 相似文献
74.
Emel Karakılıç Şule Baran Hatice Öğütçü Atilla Akdemir Arif Baran 《Archiv der Pharmazie》2020,353(3):1900267
An efficient and versatile synthesis method has been postulated for hydroxymethylated rac - and meso-cyclohexanoid derivatives. The synthesis of these stereoisomers was achieved easily with traditional methods using hexahydroisobenzofuran 6 , prepared from commercially available cis-hydrophthalic anhydride. The study, involving diastereoselective epoxidation and cis-hydroxylation, was conducted to obtain epoxy-, cis-, and trans-diol-furans 7, 8 , and 9 . After sulfamic acid-catalyzed ring-opening reaction of the epoxide and furan rings, rac- and meso-tetraacetates 14, 15 , and 16 were afforded. Hydrolysis of acetate groups with ammonia in absolute methanol yielded the desired tetrols rac -17 , meso -18 , and meso -19 . All structures, after purification by chromatographic methods and elucidation by spectral techniques, were screened against α- and β-glucosidases. Compounds 7, 8, 10, 17, 18 , and 19 were also evaluated for their antibacterial and antifungal activity against some selected synthesized compounds with varying degrees of inhibitory effects on the growth of different pathogenic microorganisms by the well-diffusion method. In addition, Saccharomyces cerevisiae α-glucosidase molecular modeling studies were performed for all rac- and meso-compounds 7, 8, 10, 17, 18 , and 19 . 相似文献
75.
Synthesis of primaquine glyco‐conjugates as potential tissue schizontocidal antimalarial agents 下载免费PDF全文
Chandra S. Azad Mridula Saxena Arif J. Siddiqui Jyoti Bhardwaj Sunil K. Puri Guru P. Dutta Nitya Anand Anil K. Saxena 《Chemical biology & drug design》2017,90(2):254-261
Primaquine ( PQ ) is the only drug used to prevent relapse of malaria due to P. vivax and P. ovale, by eradicating the dormant liver form of the parasite (hypnozoites). The side‐effects associated with PQ limits is uses in treatment of malaria. To overcome the premature oxidative deamination and to increase the life span of drug in the biological system, the novel glyco‐conjugates of PQ were synthesized by coupling of primaquine with hexoses in phosphate buffer. The saccharide part of the hybrid molecules thought to direct the drug to the liver, where hypnozoites resides. All the synthesized compounds were fully characterized and evaluated for their radical curative activities. The three compounds viz glucoside ( 15a ), galactoside ( 15b ) and mannoside ( 15c ) with high activity were tested for their activity in rhesus monkeys where the most active compound 15b showed twofold activity (100% radical curative activity at 1.92 mmol/kg) than the standard drug PQ diphosphate (3.861 mmol/kg). It is proposed that results from these studies may be advantageous to develop a new potent tissue schizonticide antimalarial compound. 相似文献
76.
77.
MK-801, a noncompetitive N-methyl-d-aspartate (NMDA) receptor antagonist, produces neurotoxicity in adult rodent brain, and causes schizophrenia-like psychosis and cognitive dysfunction. Since neuropeptides and neuropeptide-degrading enzymes play important roles in cognitive function, we examined whether or not MK-801-induced schizophrenia-like psychosis is co-related with the changes of these enzymes in rat brain regions. In the present study, we investigated the effect of systemic treatment with MK-801 (0.5mg/kg) on neuropeptide-degrading enzymes, prolyl oligopeptidase (POP) and thimet oligopeptidase (EP 24.15), and glial marker proteins GFAP and CD11b in rat brain regions. The levels of POP and EP 24.15 activities increased significantly three days after treatment with MK-801 in the posterior cingulate/retrosplenial cortices (PC/RSC). Since atypical neuroleptic clozapine but not typical neuroleptic haloperidol prevents the MK-801-induced schizophrenia-like symptoms, we further examined the pretreated effects of the neuroleptics. Clozapine, but not haloperidol, significantly attenuated MK-801-induced changes in the levels of the neuropeptide-degrading enzymes. Immunohistochemical studies on GFAP and CD11b showed the increase in the PC/RSC of MK-801-treated rat brain and the pretreatment with clozapine suppressed these changes. Double immunostain experiments of EP 24.15 and GFAP antibodies demonstrated some co-localization of the neuropeptidase with astrocytes. The present findings suggest that change of neuropeptidases in the brain is in part correlated with changes of glial cells, and may play an important role in the control of schizophrenia-like psychotic disorders. 相似文献
78.
Hoyer J Dreweke A Becker C Göhring I Thiel CT Peippo MM Rauch R Hofbeck M Trautmann U Zweier C Zenker M Hüffmeier U Kraus C Ekici AB Rüschendorf F Nürnberg P Reis A Rauch A 《Journal of medical genetics》2007,44(10):629-636
Background
Using array techniques, it was recently shown that about 10% of patients with mental retardation of unknown origin harbour cryptic chromosomal aneusomies. However, data analysis is currently not standardised and little is known about its sensitivity and specificity.Methods
We have developed an electronic data analysis tool for gene‐mapping SNP arrays, a software tool that we call Copy Number Variation Finder (CNVF). Using CNVF, we analysed 104 unselected patients with mental retardation of unknown origin with a genechip mapping 100K SNP array and established an optimised set of analysis parameters.Results
We detected deletions as small as 20 kb when covered by at least three single‐nucleotide polymorphisms (SNPs) and duplications as small as 150 kb when covered by at least six SNPs, with only one false‐positive signal in six patients. In 9.1% of patients, we detected apparently disease‐causing or de novo aberrations ranging in size from 0.4 to 14 Mb. Morphological anomalies in patients with de novo aberrations were equal to that of unselected patients when measured with de Vries score.Conclusion
Our standardised CNVF data analysis tool is easy to use and has high sensitivity and specificity. As some genomic regions are covered more densely than others, the genome‐wide resolution of the 100K array is about 400–500 kb for deletions and 900–1000 kb for duplications. The detection rate of about 10% of de novo aberrations is independent of selection of patients for particular features. The incidental finding in two patients of heterozygosity for the 250 kb recurrent deletion at the NPH1 locus, associated with autosomal recessive juvenile nephronophthisis, which was inherited from a healthy parent, highlights the fact that inherited aberrations might be disease‐related even though not causal for mental retardation. 相似文献79.
Uz E Bavbek N Turgut FH Kanbay M Kaya A Akcay A 《Journal of the National Medical Association》2007,99(9):1066-1067
Drug-induced lupus erythematosus (DILE) is a syndrome that shares symptoms and laboratory characteristics with idiopathic systemic lupus erythematosus. Recognition of DILE is important because it usually reverts within a few weeks after stopping the offending drug. Antibiotics are uncommonly associated with DILE, and cefuroxime has never been incriminated as a cause. We present herein the first case of DILE induced by cefuroxime. Although this is the first report of cefuroxime-induced DILE, we should be aware of this occurrence. 相似文献
80.
Susan M. Tarlo Ahmed A. Arif George L. Delclos Paul Henneberger Jenil Patel 《Annals of epidemiology》2018,28(6):392-400