全文获取类型
收费全文 | 23605篇 |
免费 | 2115篇 |
国内免费 | 58篇 |
专业分类
耳鼻咽喉 | 224篇 |
儿科学 | 677篇 |
妇产科学 | 583篇 |
基础医学 | 2767篇 |
口腔科学 | 431篇 |
临床医学 | 2426篇 |
内科学 | 4830篇 |
皮肤病学 | 406篇 |
神经病学 | 2184篇 |
特种医学 | 964篇 |
外国民族医学 | 3篇 |
外科学 | 3449篇 |
综合类 | 533篇 |
一般理论 | 43篇 |
预防医学 | 2520篇 |
眼科学 | 323篇 |
药学 | 1573篇 |
中国医学 | 31篇 |
肿瘤学 | 1811篇 |
出版年
2022年 | 145篇 |
2021年 | 358篇 |
2020年 | 204篇 |
2019年 | 404篇 |
2018年 | 513篇 |
2017年 | 354篇 |
2016年 | 325篇 |
2015年 | 423篇 |
2014年 | 575篇 |
2013年 | 864篇 |
2012年 | 1170篇 |
2011年 | 1195篇 |
2010年 | 779篇 |
2009年 | 695篇 |
2008年 | 1118篇 |
2007年 | 1213篇 |
2006年 | 1210篇 |
2005年 | 1195篇 |
2004年 | 1077篇 |
2003年 | 995篇 |
2002年 | 920篇 |
2001年 | 611篇 |
2000年 | 638篇 |
1999年 | 586篇 |
1998年 | 336篇 |
1997年 | 259篇 |
1996年 | 271篇 |
1995年 | 268篇 |
1994年 | 219篇 |
1993年 | 205篇 |
1992年 | 433篇 |
1991年 | 422篇 |
1990年 | 363篇 |
1989年 | 389篇 |
1988年 | 372篇 |
1987年 | 336篇 |
1986年 | 303篇 |
1985年 | 332篇 |
1984年 | 264篇 |
1983年 | 221篇 |
1982年 | 177篇 |
1981年 | 155篇 |
1979年 | 245篇 |
1978年 | 179篇 |
1977年 | 149篇 |
1974年 | 150篇 |
1973年 | 190篇 |
1972年 | 186篇 |
1971年 | 158篇 |
1969年 | 147篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
J C McIntosh J W Simecka S E Ross J K Davis E J Miller G H Cassell 《Infection and immunity》1992,60(7):2936-2942
Chronic infections play a significant role in the morbidity and mortality of patients with chronic airflow limitation. By stimulating airway inflammation, persistent infection has the potential to cause airway fibrosis. However, in patient this condition is most typically found in lungs damaged by other factors, such as smoking, abnormal secretions, or barotrauma. We report the characterization of Mycoplasma pulmonis infection-induced lung fibrosis in two immunocompetent rat strains with no preexisting lung disease. The fibrosis was predominantly in the airways, as demonstrated by the findings for infected animals of increased airway inflammation, airway fibrosis, and airway wall thickness, which correlated with the collagen content of the lungs. Also, the physiological alterations were the opposite of those found in interstitial fibrosis, with a positive correlation between lung compliance and collagen content. The airway fibrosis was noted earlier and to a greater extent in Lewis rats than in Fisher rats, and this result apparently was related to regulation of the inflammatory response. Airway wall thickness, airway inflammation, and airway fibrosis are commonly reported in tissue specimens from patients with chronic airway diseases and have been shown to correlate with airflow limitation in patients with chronic obstructive pulmonary disease. Thus, this model may be useful in furthering our understanding of the role of chronic infection and airway inflammation in airflow obstruction. 相似文献
92.
DOWN-REGULATION OF C-MYC ONCOGENE DURING NGF-INDUCED DIFFERENTIATION OF NEUROBLASTOMA CELL LINES 总被引:1,自引:0,他引:1
DOWN-REGULATIONOFC-MYCONCOGENEDURINGNGF-INDUCEDDIFFERENTIATIONOFNEUROBLASTOMACELLLINESChenJie(陈杰),LiuTonghua(刘彤华)andAlonzoHRo... 相似文献
93.
R. Kristeva-Feige H. Walter B. Lütkenhöner S. Hampson B. Ross U. Knorr H. Steinmetz D. Cheyne 《The European journal of neuroscience》1994,6(4):632-639
Movement-related neuromagnetic fields from eight healthy human subjects were investigated in a Bereitschaftspotential paradigm. The three conditions studied were right-sided mouth, index finger and foot movement. The neuromagnetic field patterns corresponding to the motor field and the movement-evoked field I were analysed using a moving dipole model. For both components a somatotopic organization was found: the estimated dipole locations for the mouth were more lateral and those for the foot more medial than the estimated dipole positions for the index finger movement. With regard to possible clinical applications, e.g. non-invasive mapping of the sensorimotor cortex and studies of plasticity of the motor function, the present results suggest that the investigation of movement-evoked field I for the index finger condition is most likely to yield further results. 相似文献
94.
A S Mark P Blake S W Atlas M Ross D Brown M Kolsky 《AJNR. American journal of neuroradiology》1992,13(5):1463-1470
PURPOSE: To describe a radiographic finding--enhancement of the cisternal portion of the third cranial nerve on postcontrast MR--and to correlate it with patients' clinical symptoms and ultimate diagnosis. MATERIALS AND METHODS: Thirteen consecutive patients with enhancement of the cisternal portion of the third cranial nerve on postcontrast MR were retrospectively identified; 50 control patients referred for pituitary microadenomas were also retrospectively reviewed. FINDINGS: The enhancement was bilateral in six patients and unilateral in seven patients. Four of the six patients with bilateral enhancement had unilateral oculomotor nerve palsies; none had bilateral third cranial nerve palsy. Five of the seven patients with unilateral enhancement had ipsilateral third nerve palsies. Of the nine patients with third nerve palsies, the pupil was involved in four patients. Follow-up studies were available in six patients, four of whom had third nerve palsy. Resolution of the enhancement correlated with resolution of the symptoms in two patients. The patients' underlying diagnoses were lymphoma (four), leukemia (one), viral meningitis (one), neurofibromatosis (two), inflammatory polyneuropathy-HIV related (one), ophthalmoplegic migraine (one), Tolosa-Hunt syndrome (one), coccidioidomycosis (one), and diabetes (one). No enhancement was seen in any of the controls. CONCLUSION: Enhancement of the cisternal segment of the third cranial nerve is always abnormal, revealing an underlying inflammatory or neoplastic process. However, it is not always associated with clinically apparent oculomotor nerve dysfunction. 相似文献
95.
96.
97.
Harry Pantazopoulos Nicholas Lange Ross J Baldessarini Sabina Berretta 《Neuropsychopharmacology》2007,61(5):640-652
BACKGROUND: Growing evidence indicates that the entorhinal cortex (ECx) might be affected in schizophrenia (SZ) and bipolar disorder (BD). To test whether distinct interneuronal subpopulations might be altered, numbers of parvalbumin-immunoreactive (PVB-IR) neurons were measured in the ECx of BD and SZ subjects. These neurons play a pivotal role within ECx intrinsic circuits. METHODS: Numbers, numerical density, and soma size of PVB-IR neurons were measured in the ECx of normal control (n = 16), BD (n = 10), and SZ (n = 10) subjects. The volume of the ECx was measured in Nissl-stained sections. RESULTS: In BD, decreases of total numbers (p = .02) and numerical densities (p = .01) of PVB-IR neurons were detected in the ECx. Within distinct subregions, reductions were detected in the superficial layers of the lateral (p = .02), intermediate (p = .04), and caudal (p = .01) ECx. In SZ, total numbers and numerical densities were not altered. A reduction of soma size was present in the intermediate ECx (p = .01). Volume was unaffected in either disorder. CONCLUSIONS: In BD, a decrease of PVB-IR neurons may alter intrinsic inhibitory networks within the superficial layers of the ECx. The likely consequence is a disruption of integration and transfer of information from the cerebral cortex to the hippocampus. 相似文献
98.
Oluseun A Sowemimo Steven M Yood John Courtney Jessie Moore Miriam Huang Rebecca Ross Ursula McMillian Peter Ojo Randolph B Reinhold 《Surgery for obesity and related diseases》2007,3(1):73-7; discussion 77
BACKGROUND: To study the mortality among morbidly obese patients qualifying for bariatric surgery. Mortality from bariatric surgery for morbid obesity has been widely reported; however, little is known about the mortality in morbidly obese patients who defer surgery. METHODS: Consecutive patients evaluated for bariatric surgery with an initial encounter between 1997 and 2004 were identified. The Social Security Death Index and office records were used to identify mortality through 2006. We conducted telephone interviews to determine whether the 305 patients who did not undergo bariatric surgery at our institution had undergone the surgery elsewhere. Using Cox proportional hazards models, we compared the mortality in patients undergoing surgery with that of those who did not. To evaluate bias resulting from missing data, we conducted analyses assuming that all patients with missing data had (1) undergone surgery and (2) not undergone surgery. RESULTS: A total of 908 patients underwent bariatric surgery (880 patients at our institution and 28 patients elsewhere). A total of 112 patients did not undergo surgery. Data regarding surgery on 165 patients could not be obtained. The mortality in those patients who did not undergo surgery was 14.3% compared with 2.9% for those who did undergo surgery. Adjusting for age, gender, and body mass index, patients who had undergone surgery had an 82% reduction in mortality (hazard ratio 0.18, 95% confidence interval 0.09-0.35, P <.0001). Sensitivity analysis, assuming that all patients with missing data received surgery resulted in an 85% mortality reduction (P <.001) and assuming that patients did not receive surgery resulted in a 50% mortality reduction (P = .04). CONCLUSIONS: Mortality among morbidly obese patients without surgery was 14.3% during the study period. Surgical intervention offered a 50%-85% mortality reduction benefit. 相似文献
99.
Anna B Blazej Z Jacqueline G Andrew CJ Jeffrey R Andrzej S 《Expert review of dermatology》2007,2(4):451-469
Melanoma consists 4-5 % of all skin cancers, but it contributes to 71-80 % of skin cancers deaths. UV light affects cell and tissue homeostasis due to its damaging effects on DNA integrity and modification of expression of a plethora of genes. DNA repair systems protect cells from UV-induced lesions. Several animal models of melanoma have been developed (Xiphophorus, Opossum Monodelphis domestica, mouse models and human skin engrafts into other animals). This review discusses possible links between UV and genes significantly related to melanoma but does not discuss melanoma genetics. These include oncogenes, tumor suppressor genes, genes related to melanocyte-keratinocyte and melanocyte-matrix interaction, growth factors and their receptors, CRH, ACTH, α-MSH, glucocorticoids, ID1, NF-kappaB and vitamin D3. 相似文献
100.