全文获取类型
收费全文 | 1513篇 |
免费 | 62篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 74篇 |
妇产科学 | 23篇 |
基础医学 | 262篇 |
口腔科学 | 32篇 |
临床医学 | 93篇 |
内科学 | 294篇 |
皮肤病学 | 52篇 |
神经病学 | 133篇 |
特种医学 | 71篇 |
外科学 | 170篇 |
综合类 | 24篇 |
预防医学 | 53篇 |
眼科学 | 125篇 |
药学 | 64篇 |
中国医学 | 2篇 |
肿瘤学 | 90篇 |
出版年
2023年 | 14篇 |
2022年 | 43篇 |
2021年 | 66篇 |
2020年 | 45篇 |
2019年 | 43篇 |
2018年 | 60篇 |
2017年 | 31篇 |
2016年 | 29篇 |
2015年 | 42篇 |
2014年 | 52篇 |
2013年 | 70篇 |
2012年 | 98篇 |
2011年 | 102篇 |
2010年 | 64篇 |
2009年 | 58篇 |
2008年 | 85篇 |
2007年 | 85篇 |
2006年 | 81篇 |
2005年 | 43篇 |
2004年 | 52篇 |
2003年 | 56篇 |
2002年 | 25篇 |
2001年 | 26篇 |
2000年 | 41篇 |
1999年 | 32篇 |
1998年 | 11篇 |
1997年 | 6篇 |
1996年 | 7篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 7篇 |
1992年 | 14篇 |
1991年 | 18篇 |
1990年 | 12篇 |
1989年 | 14篇 |
1988年 | 14篇 |
1987年 | 23篇 |
1986年 | 12篇 |
1985年 | 10篇 |
1983年 | 5篇 |
1982年 | 4篇 |
1980年 | 3篇 |
1979年 | 8篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 8篇 |
1972年 | 12篇 |
1971年 | 12篇 |
1970年 | 5篇 |
1969年 | 4篇 |
排序方式: 共有1577条查询结果,搜索用时 15 毫秒
91.
92.
Guajardo JR Schleifer KW Daines MO Ruddy RM Aronow BJ Wills-Karp M Hershey GK 《The Journal of allergy and clinical immunology》2005,115(2):243-251
BACKGROUND: Asthma is the most common chronic disease of childhood and has a strong genetic component. OBJECTIVE: To identify gene expression signatures that reflect asthma-related processes and to determine whether these genes were similar or distinct between stable asthma and acute exacerbations in childhood, we profiled gene expression patterns in nasal respiratory epithelial cells. METHODS: Children who had stable asthma (asthma-S; n = 10) and children experiencing an asthma exacerbation (asthma-E; n = 10) were recruited along with nonatopic children without asthma (n = 10). RNA was prepared from nasal respiratory epithelial cells isolated from each child, initially analyzed as pooled samples from the 3 groups, and further validated by using microarrays and RT-PCR with individual patient samples. RESULTS: Distinct gene clusters were identifiable in individual and pooled asthma-S and asthma-E samples. Asthma-E samples demonstrated the strongest and most reproducible signatures, with 314 genes of 34,886 measured as present on the chip demonstrating induction or repression of greater than 2-fold with P < .05 in each of 4 individual samples. Asthma-S-regulated genes encompassed genes that overlapped with those of asthma-E but were fewer (166) and less consistent with respect to their behavior across the asthma-E patient samples. CONCLUSION: Exacerbated asthma status is readily distinguished based on the occurrence of strong gene expression signatures in nasal epithelial samples. Stable asthma status also exhibits differential signatures. The results suggest that there are independent gene expression signatures reflective of cells and genes poised or committed to activation by an asthma attack. 相似文献
93.
Mitochondrially targeted vitamin E and vitamin E mitigate ethanol-mediated effects on cerebellar granule cell antioxidant defense systems 总被引:2,自引:0,他引:2
Siler-Marsiglio KI Pan Q Paiva M Madorsky I Khurana NC Heaton MB 《Brain research》2005,1052(2):202-211
Ethanol (EtOH) disrupts the structure and function of the developing nervous system, sometimes leading to birth defects associated with fetal alcohol syndrome (FAS). Animal FAS models indicate that cellular membrane peroxidation, intracellular oxidant accumulation, and suppression of endogenous antioxidant enzymes contribute to the toxic effects of EtOH. Mitochondrially targeted vitamin E (MitoVit E), a chemically engineered form of vitamin E (VE) designed to accumulate in the mitochondria, has been shown to inhibit intracellular oxidant accumulation and cell death more effectively than VE. In previous investigations, we have shown that, in vivo, VE reduces neuronal death in the developing cerebellum of EtOH-exposed animals, and, in vitro, VE prevents apoptotic and necrotic death of EtOH-exposed cerebellar granule cells (CGCs). The present investigation shows that, in a FAS CGC model, 1 nM MitoVit E renders significant neuroprotection against EtOH concentrations as high as 1600 mg/dL. The present study also demonstrates that, in this same model, MitoVit E mitigates EtOH-induced accumulation of intracellular oxidants and counteracts suppression of glutathione peroxidase/glutathione reductase (GSH-Px/GSSG-R) functions, protein expression of gamma-glutamylcysteine synthetase (gamma-GCS), and total cellular glutathione (GSH) levels. In the presence and absence of EtOH, VE amplifies the protein expression levels of gamma-GCS, an enzyme that performs the rate-limiting step for GSH synthesis, and total GSH levels. These results suggest that MitoVit E and VE ameliorate EtOH toxicity through non-oxidant mechanisms-modulations of endogenous cellular proteins-and antioxidant means. 相似文献
94.
A 19-year-old male presented with linear raised lesions over extensive areas of his body that followed Blaschko's lines. The lesions were asymptomatic with ridged borders. Histopathology confirmed a diagnosis of porokeratosis. He was given topical tretinoin and topical flourouracil for local application on specified areas. The cosmetic acceptability and the safety profile of tretinoin were found to be better than those of flourouracil. However, both the agents were equally efficacious. A rare case of extensive porokeratosis with comparative evaluation of two treatment modalities is hereby presented. 相似文献
95.
Enhancing encoding of a motor memory in the primary motor cortex by cortical stimulation 总被引:3,自引:0,他引:3
Motor training results in encoding of motor memories, a form of use-dependent plasticity. Here we tested the hypothesis that transcranial magnetic stimulation (TMS) synchronously applied to a motor cortex engaged in a motor training task could enhance this plastic process. Healthy volunteers were studied in four sessions: training consisting of performance of directionally specific voluntary thumb movements (Train alone), training with TMS delivered during the execution of the training movement in a strictly temporal relationship to the motor cortex contralateral (Train+TMS synchronous(contra)) and ipsilateral (Train+TMS synchronous(ipsi)) to the training hand, and training with TMS delivered asynchronous to the training movement to the motor cortex contralateral to the training hand (Train+TMS asynchronous(contra)). Train alone, Train+TMS synchronous(contra), and Train+TMS asynchronous(contra) but not Train+TMS synchronous(ipsi) elicited a clear motor memory. The longevity of the encoded memory was significantly enhanced by Train+TMS synchronous(contra) when compared with Train alone and Train+TMS asynchronous(contra). Therefore use-dependent encoding of a motor memory can be enhanced by synchronous Hebbian stimulation of the motor cortex that drives the training task and reduced by stimulation of the homologous ipsilateral motor cortex, a result relevant for studies of cognitive and physical rehabilitation. 相似文献
96.
Mental health status of runaway adolescents 总被引:1,自引:0,他引:1
There are 47.22 million homeless and runaway adolescents roaming on the streets of our country (Voluntary Health Association
of India — VHAI) of which one lakh are in Delhi. Very little is known about them, their needs or their experiences.Objective: (1) To assess the psychological problems amongst the runaway adolescent boys. (2) To determine possible risk factors.Methods: This study was cross-sectional in design and done at a child observation home for boys in Delhi. All runaway boys aged 10
to 16 years of age were included in the study. The study was conducted from 15th June to 15th July 2001. A comprehensive schedule consisting of five parts, viz identification data, hopelessness scale for children by
Kazdin, Beck depression inventory, Psychological survey questionnaire and RUTTER-B2 scale were used to assess various mental
health problems.Results: 20.7% of children were found to have high hopelessness and 8% of children had depression. 2% of children revealed that they
had attempted suicide at any point of time in life. Among children with high hopelessness, 3.2% had ever attempted suicide.
8.3% of the depressed children gave history of suicidal attempts. 38% of children gave history of physical abuse, 14.6% of
sexual abuse and a large number reported substance abuse. 69.33% were found to have behavioral problems (i.e. scored above
the recommended cut off score of 9). 81% of children had antisocial behavior, 7.8% were neurotic and 10.5% remained undifferentiated.Conclusion: Runaway adolescents suffer from a wide array of mental health problems and there is a need for a broad based psychosocial
intervention programme. 相似文献
97.
Postoperative rhabdomyolysis following laparoscopic gastric bypass in the morbidly obese 总被引:4,自引:0,他引:4
Khurana RN Baudendistel TE Morgan EF Rabkin RA Elkin RB Aalami OO 《Archives of surgery (Chicago, Ill. : 1960)》2004,139(1):73-76
HYPOTHESIS: Laparoscopic approaches for weight reduction in the morbidly obese have become common with more than 50,000 bariatric surgical procedures being performed in 2001. The objective of this article is to raise awareness among surgeons of a new complication of rhabdomyolysis from this frequent procedure. DESIGN: Case series extracted from surgical database from January 2, 2001, through December 31, 2002. PATIENTS AND METHODS: We identified 5 cases of postoperative rhabdomyolysis in morbidly obese patients who underwent laparoscopic duodenal switch procedures with parietal gastrectomy. The cause, pathogenesis, and clinical features are reviewed and discussed. RESULTS: Postoperative rhabdomyolysis developed in 5 of 353 morbidly obese patients who underwent consecutive laparoscopic duodenal switch procedures, an incidence of 1.4%. All 5 patients were male, had a mean peak serum creatine kinase level of 19 680 U/L, and reported muscle pain in either the buttock, hip, or shoulder regions during the early postoperative period. CONCLUSIONS: We hypothesized that morbidly obese patients develop critical surface and deep tissue pressures during bariatric surgery, increasing their risk for tissue injury and rhabdomyolysis. Unexplained elevations in the serum creatinine level or reports of buttock, hip, or shoulder pain in the postoperative period should raise the possibility of rhabdomyolysis and prompt clinical investigation. We recommend routine preoperative and postoperative measurements of the serum creatine kinase and serum creatinine levels to aid detection. Surgeons need to keep a low index of suspicion because early diagnosis and treatment are the cornerstones of successful management of rhabdomyolysis. 相似文献
98.
A pilot study of dendroaspis natriuretic peptide in aneurysmal subarachnoid hemorrhage 总被引:1,自引:0,他引:1
Khurana VG Wijdicks EF Heublein DM McClelland RL Meyer FB Piepgras DG Burnett JC 《Neurosurgery》2004,55(1):69-75; discussion 75-6
OBJECTIVE: Hypovolemia after aneurysmal subarachnoid hemorrhage (SAH) may be mediated by natriuretic peptides and can further impair cerebral perfusion in dysautoregulated and vasospastic arterial territories. Dendroaspis natriuretic peptide (DNP), derived from the venom of Dendroaspis augusticeps, the Green Mamba snake, has recently been discovered in human plasma and atrial myocardium. There is no information regarding the presence or putative role of this peptide in patients with aneurysmal SAH. METHODS: A sensitive and specific DNP radioimmunoassay was performed on venous blood samples obtained on post-SAH Days 1, 3, and 7 from 10 consecutive SAH patients (cases) and randomly from 9 healthy volunteers (controls). Clinical and laboratory data, including daily serum sodium concentration and fluid balance, were collected prospectively up to 7 days after the ictus. RESULTS: Increase in plasma DNP levels occurred in five (63%) of eight patients who had DNP levels measured on Days 1 and 3 (mean increase, 29%). An increase in DNP level was significantly associated with development of a negative fluid balance (P = 0.003) and hyponatremia (P = 0.008). Three (75%) of the four patients who developed cerebral vasospasm during this study experienced an increase in DNP levels from Days 1 to 3. CONCLUSION: The present study is the first to find a significant association between elevated levels of DNP, a new member of the natriuretic peptide family, and the development of diuresis and natriuresis in patients with aneurysmal SAH. Our findings warrant further investigation by means of a large-scale, prospective, case-control study. 相似文献
99.
Gamna Gandy bodies are usually seen in spleen in cases of chronic venous congestion. We present a case of CML showing gamna gandy bodies. These may have occurred as a part of evolving portal hypertension which maybe due to antileukemic therapy or CML per se or due to a combination of both factors. 相似文献
100.