全文获取类型
收费全文 | 679篇 |
免费 | 53篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 36篇 |
妇产科学 | 13篇 |
基础医学 | 91篇 |
口腔科学 | 9篇 |
临床医学 | 73篇 |
内科学 | 141篇 |
皮肤病学 | 25篇 |
神经病学 | 38篇 |
特种医学 | 96篇 |
外科学 | 43篇 |
综合类 | 16篇 |
预防医学 | 72篇 |
眼科学 | 6篇 |
药学 | 61篇 |
肿瘤学 | 31篇 |
出版年
2021年 | 7篇 |
2019年 | 13篇 |
2018年 | 9篇 |
2017年 | 4篇 |
2016年 | 14篇 |
2015年 | 17篇 |
2014年 | 18篇 |
2013年 | 24篇 |
2012年 | 21篇 |
2011年 | 24篇 |
2010年 | 26篇 |
2009年 | 22篇 |
2008年 | 22篇 |
2007年 | 40篇 |
2006年 | 23篇 |
2005年 | 25篇 |
2004年 | 16篇 |
2003年 | 21篇 |
2002年 | 13篇 |
2001年 | 19篇 |
2000年 | 20篇 |
1999年 | 21篇 |
1998年 | 16篇 |
1997年 | 23篇 |
1996年 | 16篇 |
1995年 | 18篇 |
1994年 | 13篇 |
1993年 | 14篇 |
1992年 | 7篇 |
1991年 | 10篇 |
1990年 | 11篇 |
1989年 | 22篇 |
1988年 | 19篇 |
1987年 | 14篇 |
1986年 | 26篇 |
1985年 | 13篇 |
1984年 | 5篇 |
1983年 | 7篇 |
1982年 | 10篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1979年 | 4篇 |
1977年 | 11篇 |
1976年 | 9篇 |
1975年 | 4篇 |
1972年 | 4篇 |
1971年 | 5篇 |
1970年 | 5篇 |
1969年 | 6篇 |
1966年 | 6篇 |
排序方式: 共有754条查询结果,搜索用时 15 毫秒
1.
JN Blau 《Cephalalgia : an international journal of headache》1993,13(4):293-295
Although nausea and vomiting are diagnostic migraine symptoms, most patients can take tablets by mouth and a few say they can eat some food. This study was conducted to determine the proportion who could eat or drink, what was consumable and with what effect. One-hundred-and-nine migraineurs were asked what they could eat or drink at the beginning or height of their attacks; 59 could not take any food by mouth, but 50 could eat during the headache phase of their migraine attacks. Four ate normally, 5 took smaller amounts of their normal dietary intake, and 3 took lighter meals. Dry, carbohydrate foods were consumable by the remaining 38: a few had specific cravings, most stated the precise variety which, when eaten, reduced nausea, headache, other symptoms or length of attacks. Patients should therefore be encouraged to eat what they can tolerate, with their tablets taken as early as possible after the onset of attacks. Simultaneous nausea, tolerance or even craving for specific foods occur in other conditions, particularly high altitude headaches which share other features of migraine attacks. The observations in this paper support the notion that migraine is a central neuronal metabolic disturbance. 相似文献
2.
We performed a longitudinal analysis of serum interleukin-2 (IL-2) and soluble IL-2 (sIL-2R) concentrations in 60 patients with relapsing-remitting (R-R) multiple sclerosis (MS) as well as in 33 age- and sex-matched normal controls. Overall, we found that serum IL-2 levels remained low (less than 10 U/ml) and did not change appreciably over time; however, marked fluctuations in sIL-2R levels were observed in both the patient and control groups. Using patients as their own controls, we calculated an interrelapse (disease stable) mean sIL-2R concentration as a baseline for comparison with relapse values; sIL-2R levels greater than the 90th percentile of the Student's t distribution of stable values were defined as "peaks." There were a total of 27 sIL-2R peaks, eight (30%) of which correlated with clinical relapses but were potentially predictive of only 18% (8/45) of all the recorded clinical relapses. There was no difference in disease severity (Expanded Disability Status Scale) score between peak-correlated and noncorrelated relapses. Our data suggest that despite reports of elevated levels of IL-2 and sIL-2R in MS, neither may be a useful marker for predicting clinical disease activity in R-R MS. 相似文献
3.
Immunoglobulin M antibody capture enzyme-linked immunosorbent assay for diagnosis of St. Louis encephalitis 总被引:2,自引:8,他引:2 下载免费PDF全文
T P Monath R R Nystrom R E Bailey C H Calisher D J Muth 《Journal of clinical microbiology》1984,20(4):784-790
Sera from patients with St. Louis encephalitis were tested with an immunoglobulin M (IgM) antibody capture enzyme immunoassay (MAC ELISA). The assay used five reagents: antihuman IgM, test serum, sucrose-acetone-extracted mouse brain antigen, broadly cross-reactive flavivirus monoclonal antibody conjugated to alkaline phosphatase, and substrate (p-nitrophenyl phosphate). MAC ELISA endpoint titers correlated (r = 0.893) with the absorbance value of a 1:100 dilution of patient serum. Significant (fourfold or greater) changes in the endpoint titers between paired sera corresponded to a critical ratio (ratio of absorbance values at the 1:100 dilution) of greater than or equal to 1.3. IgM antibodies were detected in 71% of patients bled at 0 to 3 days after the onset of illness, in 99% bled at 4 to 21 days, and in 91% bled at 22 to 67 days. Thereafter, the IgM seropositivity rate declined; however, 29% of sera were still positive at 115 to 251 days after the onset of illness. MAC ELISA titers were significantly correlated with hemagglutination inhibition (r = 0.258) and neutralization (r = 0.711) titers. Because IgM antibodies appeared early and waned rapidly, a diagnosis was made on the basis of a decrease in titer more often by MAC ELISA than by hemagglutination inhibition, complement fixation, or neutralization tests. IgM antibodies generally showed a high degree of specificity; heterologous cross-reactions were, however, present in 4 of 14 sera examined. The MAC ELISA is useful for the rapid, early diagnosis of St. Louis encephalitis. 相似文献
4.
OBJECTIVES: To determine the spectrum of N and G genotypes of respiratory syncytial virus (RSV) causing respiratory tract infection and whether particular genotypes are associated with severity of infection. PATIENTS AND METHODS: Nasopharyngeal aspirates (NPAs) were obtained from 114 infants with acute respiratory tract infection due to RSV over two seasons. Viral mRNA was extracted from NPAs or cultured virus, reverse transcribed, and the cDNA amplified by the polymerase chain reaction using primers directed to parts of the N and G gene respectively. Amplicons were separately digested with four different restriction endonucleases for each gene. The fragments were separated by agarose gel, electrophoresis, and the electrophoretic patterns used to assign the various genotypes. Disease severity was assessed as very mild (upper respiratory tract signs only), mild (coryza and signs of lower respiratory tract infection), moderate (requiring nasogastric or intravenous fluids), and severe (requiring oxygen or ventilation). RESULTS: Five of the six known N genotypes were detected, but NP4 and NP2 were found most frequently. There was no association between N genotype and disease severity. Six G (SHL) genotypes were detected. Significantly (p = 0.04) more of the infants infected with the SHL2 genotype had severe or moderate disease. CONCLUSIONS: During the seasonal peaks of RSV respiratory tract infection at least 10 different RSV genotypes cocirculated. While there is no association between N genotypes and disease severity, infection with the SHL2 G genotype appears to result in moderate to severe disease. 相似文献
5.
6.
During a 20-month period, fractures of the clivus occurring after craniocerebral trauma were diagnosed with computed tomography (CT) in 11 patients. Five patients had longitudinally oriented fractures; these were fatal in four patients due to either vertebral-basilar artery occlusion, brain stem trauma, or both. Six other patients had transversely oriented fractures that extended through the carotid canal and petrous temporal bone. While less frequently contributing directly to mortality, transverse fractures were also associated with cerebrospinal fluid leaks (two patients) and a cavernous sinus-carotid fistula (one patient). They were not as frequently associated with Horner syndrome or cranial nerve deficits as suggested in the current literature. This retrospective evaluation reveals two distinct injury patterns that demonstrate a difference in related morbidity and mortality. 相似文献
7.
8.
9.
Dr. C. M. Muth 《Notfall & Rettungsmedizin》2005,8(3):223-233
Aspiration is defined as the inhalation of oropharyngeal or gastric contents into the respiratory tract. Several pulmonary syndromes may occur after aspiration, depending on the amount and nature of the aspirated material, the frequency of aspiration, and the host’s response to the aspirated material. The so-called Mendelson’s syndrome is a chemical injury leading to pneumonitis and caused by the inhalation of sterile but acidic gastric content. Aspiration pneumonia in contrast is caused by the inhalation of oropharyngeal secretions that are colonized by pathogenic bacteria. Other aspiration syndromes include airway obstruction, exogenous lipoid pneumonia, and near drowning. Pulmonary aspiration is an important cause of serious illness and even death; however, the major pulmonary aspiration syndromes are frequently misdiagnosed and poorly treated. 相似文献
10.
Stacey Rolak Arjang Djamali Didier A. Mandelbrot Brenda L. Muth Margaret R. Jorgenson Weixiong Zhong Patricia Liu Brad C. Astor Sandesh Parajuli 《Transplantation proceedings》2021,53(5):1462-1469
Delayed graft function (DGF) after kidney transplantation is associated with an increased risk of graft failure. We studied the histologic findings among adult kidney transplant recipients transplanted between January 2000 and June 2015 who had DGF and had a kidney biopsy within 14 days of transplant. Death censored graft failure (DCGF) and death at 1 and 3 years after transplant were examined. A total of 269 transplant recipients fulfilled our selection criteria, of which 152 (56.51%) had acute tubular necrosis (ATN), 44 (16.4%) had acute rejection (AR), mainly T-cell mediated rejection (n = 31), 35 (13%) had ATN with AR (mainly T-cell mediated rejection, n = 26), and 38 (14.1%) had other pathology. Compared with those with ATN alone, kidney transplant recipients with AR alone had a significantly higher risk of DCGF at 1 year post transplant (adjusted hazard ratio = 3.70; 95% confidence interval 1.5-9.5; P = .006). Those with AR alone had an increased risk of DCGF at 3 years post transplant (hazard ratio = 3.10; 95% confidence interval 1.3-8.5; P = .01) in crude analyses. There was no association between DGF etiology and mortality. Early renal biopsy can be used to distinguish AR, which has protocolized treatments, from other etiologies. This could potentially alter allograft survival within 1 year of transplant complicated by DGF. 相似文献