全文获取类型
收费全文 | 1527篇 |
免费 | 69篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 72篇 |
妇产科学 | 39篇 |
基础医学 | 166篇 |
口腔科学 | 48篇 |
临床医学 | 78篇 |
内科学 | 296篇 |
皮肤病学 | 18篇 |
神经病学 | 113篇 |
特种医学 | 47篇 |
外科学 | 300篇 |
综合类 | 50篇 |
预防医学 | 52篇 |
眼科学 | 24篇 |
药学 | 144篇 |
中国医学 | 10篇 |
肿瘤学 | 128篇 |
出版年
2024年 | 6篇 |
2023年 | 17篇 |
2022年 | 12篇 |
2021年 | 50篇 |
2020年 | 26篇 |
2019年 | 43篇 |
2018年 | 45篇 |
2017年 | 29篇 |
2016年 | 32篇 |
2015年 | 41篇 |
2014年 | 57篇 |
2013年 | 73篇 |
2012年 | 93篇 |
2011年 | 118篇 |
2010年 | 54篇 |
2009年 | 43篇 |
2008年 | 77篇 |
2007年 | 93篇 |
2006年 | 67篇 |
2005年 | 68篇 |
2004年 | 54篇 |
2003年 | 38篇 |
2002年 | 64篇 |
2001年 | 40篇 |
2000年 | 30篇 |
1999年 | 24篇 |
1998年 | 15篇 |
1997年 | 10篇 |
1996年 | 6篇 |
1995年 | 12篇 |
1992年 | 16篇 |
1991年 | 14篇 |
1990年 | 12篇 |
1989年 | 17篇 |
1988年 | 15篇 |
1987年 | 23篇 |
1986年 | 17篇 |
1985年 | 16篇 |
1984年 | 7篇 |
1983年 | 8篇 |
1981年 | 7篇 |
1980年 | 7篇 |
1979年 | 14篇 |
1978年 | 10篇 |
1977年 | 7篇 |
1976年 | 8篇 |
1974年 | 8篇 |
1973年 | 9篇 |
1970年 | 5篇 |
1968年 | 12篇 |
排序方式: 共有1601条查询结果,搜索用时 31 毫秒
51.
Garg N Zivadinov R Ramanathan M Vasiliu I Locke J Watts K Lema J Rajeswary J Munschauer FE Ambrus J Weinstock-Guttman B 《Journal of neuroimmunology》2007,187(1-2):159-165
BACKGROUND: Autoreactive antibodies (ARAB) occur more frequently in patients with multiple sclerosis (MS) than in general population and the presence of these antibodies often causes uncertainty regarding the disease course, response to therapy and the diagnosis of MS. METHODS: Retrospective analyses of the ARAB, clinical and MRI data of a consecutive patient cohort of MS and clinically isolated syndrome (CIS) patients were conducted. The patients were evaluated for an extensive panel that included various subtypes of antiphospholipid antibody (APLA) including anti-phosphatidylethanolamine (APE), anti-phosphatidylserine (APS), anti-beta-2-glycoprotein-1 (ABGP), anti-cardiolipin (ACA), and several other ARAB such as antinuclear antibody (ANA), anti-neutrophilic cytoplasmic antibodies (ANCA), anti-thyroid peroxidase antibodies (ATA), anti-SS-A, and anti-SS-B antibodies. Quantitative MRI analysis was performed in a subgroup of MS patients measuring T2-lesion volume (LV), T1 black hole LV and brain parenchymal fraction (BPF). RESULTS: A total of 137 patients (mean age 44.7, 84% female) with either MS (n=111; age: mean 46.5+/-S.D. 10.3 years; disease duration: mean 13.0+/-S.D. 10.4 years; EDSS: mean 3.2+/-S.D. 1.9) or CIS (n=26; age: mean 37.7+/-S.D. 7.8 years; disease duration: mean 1.3+/-S.D. 1.1 years; EDSS: mean 1.0+/-S.D. 0.7) were enrolled. Among MS patients, 82 were RRMS, 26 SPMS, and 3 had PPMS. Seventy-seven (69%) of MS patients showed presence of one or more ARAB. The proportion of MS patients with APLA was 55% (61 patients); IgM subtype was most frequent. Co-occurrence of ACA and APE was more frequent in SPMS as compared to RRMS (15.4% vs. 1.2%, p=0.012). The proportion of CIS patients with ARAB was 75% with IgM subtype being the most frequent. However, the ARAB in majority of CIS patients (9 out of 14, 64%) were transient on repeated testing. In a subgroup of 62 MS patients, quantitative MRI analysis showed significantly higher T2-LV in patients with positive APLA (15.1 ml for APLA positive vs. 6.75 ml for APLA negative) after correcting for the disease duration (p=0.048). The patients with ATA also had significantly higher T2-LV after correction for disease duration (19.0 ml vs.8.5, p=0.044). CONCLUSIONS: ARAB were present in more than two thirds of MS and CIS patients although most of APLA in CIS were transient. The presence of APLA in MS patients was associated with higher T2-LV. 相似文献
52.
Santos R Weinstock-Guttman B Tamaño-Blanco M Badgett D Zivadinov R Justinger T Munschauer F Ramanathan M 《Journal of neuroimmunology》2006,176(1-2):125-133
The objective of this study was to evaluate multiple interferon (IFN) specific mRNA biomarkers in multiple sclerosis (MS) patients with anti-IFN-beta neutralizing antibodies (NAB) using a pharmacodynamic study design. Thirty patients were enrolled. Blood samples were drawn at pre-treatment, 4-, 8-h time points following the intramuscular dose of IFN-beta-1a. Total RNA was obtained from peripheral blood cells, processed to cDNA and analyzed using quantitative real-time polymerase chain reaction. Pre-treatment serum samples were analyzed for anti-IFN-beta binding and neutralizing antibodies: 22 patients were NAB negative; equal numbers of the eight remaining patients were either NAB positive or had borderline NAB status. The results showed that early assessment (at 4 h after IFN-beta injection) of mRNAs for Stat-1, MxA, MxB and TRAIL was more sensitive than the later measurements. Furthermore, the NAB positive patients had strongly attenuated gene expression responses on all the mRNAs. Patients with borderline NAB had average responses that appear to be lower than NAB negative patients on several genes, notably Stat-1, TRAIL and beta2 microglobulin. 相似文献
53.
Effect of Warm Ischemia Time During Laparoscopic Partial Nephrectomy on Early Postoperative Glomerular Filtration Rate 总被引:1,自引:0,他引:1
54.
Pritam Chanda Lara Sucheston Aidong Zhang Murali Ramanathan 《European journal of human genetics : EJHG》2009,17(10):1274-1286
We developed an information-theoretic metric called the Interaction Index for prioritizing genetic variations and environmental variables for follow-up in detailed sequencing studies. The Interaction Index was found to be effective for prioritizing the genetic and environmental variables involved in GEI for a diverse range of simulated data sets. The metric was also evaluated for a 103-SNP Crohn''s disease dataset and a simulated data set containing 9187 SNPs and multiple covariates that was modeled on a rheumatoid arthritis data set. Our results demonstrate that the Interaction Index algorithm is effective and efficient for prioritizing interacting variables for a diverse range of epidemiologic data sets containing complex combinations of direct effects, multiple GGI and GEI. 相似文献
55.
Mt D. Dbrssy Chockalingam Ramanathan Danesh Ashouri Vajari Yixin Tong Thomas Schlaepfer Volker A. Coenen 《The European journal of neuroscience》2021,53(1):89-113
Deep brain stimulation (DBS) in psychiatric illnesses has been clinically tested over the past 20 years. The clinical application of DBS to the superolateral branch of the medial forebrain bundle in treatment‐resistant depressed patients—one of several targets under investigation—has shown to be promising in a number of uncontrolled open label trials. However, there are remain numerous questions that need to be investigated to understand and optimize the clinical use of DBS in depression, including, for example, the relationship between the symptoms, the biological substrates/projections and the stimulation itself. In the context of precision and customized medicine, the current paper focuses on clinical and experimental research of medial forebrain bundle DBS in depression or in animal models of depression, demonstrating how clinical and scientific progress can work in tandem to test the therapeutic value and investigate the mechanisms of this experimental treatment. As one of the hypotheses is that depression engenders changes in the reward and motivational networks, the review looks at how stimulation of the medial forebrain bundle impacts the dopaminergic system. 相似文献
56.
The objective of this study was to determine the major comorbidities in patients with spastic quadriplegic (SQ) cerebral palsy (CP) and their possible clinical associations. Medical records of patients with SQ CP from a pediatric neurology practice over a 14-year period were retrospectively and systematically reviewed. Variables examined included demographics, prenatal, perinatal, and postnatal risk factors. Comorbidities documented included those involving hearing, vision, feeding status, and epilepsy. Binomial logistic regression analyses were applied to identify clinical associations of the comorbidities. Ninety-two children were included in this study of whom 39 were born preterm. Mean age of presentation was 2 months (SD 3.5) and males comprised 60% of the group. A total of 57% had a Gross Motor Function Classification Score (GMFCS) of Level IV or V. The four documented comorbidities occurred at a high frequency: 66 out of 83 children (80%) had a visual impairment with 13 (21%) having a substantial impairment; 37 out of 86 children (40%) had a hearing deficit; 43 out of 92 children (47%) had epilepsy; and 29 (33%) required assisted feeding. A GMFCS Level of IV or V and documented microcephaly was associated with the need for assisted feeding (odds ratio [OR] 8.1; 95% confidence interval [CI] 2.1-29.8, p=0.002 and OR 4.9, 95% CI 1.7-14.8, p=0.004 respectively). Epilepsy was associated with the occurrence of neonatal encephalopathy (OR 2.3, 95% CI 1.0-55; p=0.05), microcephaly (OR 4.9, 95% CI 1.6-14.8; p=0.004), periventricular leukomalacia (OR 7.4, 95% CI 1.6-35.0; p=0.012), and perinatal asphyxia (OR 3.6, 95% CI 1.5-8.9; p=0.005). There is a high frequency of comorbidity in the setting of SQ CP which can impact on quality of life and burdens of care. Few clinical associations of this burden appear, thus necessitating systematic programmatic follow-up of these children to facilitate early identification and intervention. 相似文献
57.
Shekeeb S. Mohammad FRACP Victor S.C. Fung PhD Padraic Grattan‐Smith FRACP Deepak Gill FRACP Sekhar Pillai FRACP Sudarshini Ramanathan FRACP Fabienne Brilot PhD Russell C. Dale PhD 《Movement disorders》2014,29(12):1539-1542
Accurate recognition of movement disorder phenomenology may differentiate children with anti‐N‐methyl D‐aspartate receptor (NMDAR) encephalitis, autoimmune basal ganglia encephalitis (BGE), and Sydenham's chorea (SC). Three neurologists blinded to the diagnoses recorded dominant and associated movement disorders seen on videos of 31 patients with anti‐NMDAR encephalitis (n = 10), BGE (n = 12), and SC (n = 9). Stereotypy was only seen in anti‐NMDAR encephalitis (8/10) and not in BGE and SC (P < 0.001). Perseveration was only seen in anti‐NMDAR encephalitis (5/10) and not in BGE and SC (P < 0.001). Akinesia was more commonly seen in BGE (5/12) than in anti‐NMDAR encephalitis (1/10, P = 0.097). Tremor was more commonly seen in BGE (5/12) than in anti‐NMDAR encephalitis (1/10, P = 0.097). Chorea was seen in all groups: anti‐NMDAR encephalitis (4/10), BGE (3/12), and SC (9/9). Likewise, dystonia was seen in all groups: anti‐NMDAR encephalitis (6/10), BGE (7/12), and SC (2/9). Stereotypies or perseveration are suggestive of anti‐NMDAR encephalitis, whereas their absence and the presence of akinesia and tremor is more suggestive of BGE. Chorea and dystonia are least discriminating. © 2014 International Parkinson and Movement Disorder Society 相似文献
58.
Zivadinov R Ramanathan M Dolic K Marr K Karmon Y Siddiqui AH Benedict RH Weinstock-Guttman B 《Expert Review of Neurotherapeutics》2011,11(9):1277-1294
Chronic cerebrospinal venous insufficiency (CCSVI) was recently described in multiple sclerosis patients. CCSVI is characterized by impaired brain venous drainage due to outflow obstruction in the extracranial venous system, mostly related to anomalies in the internal jugular and azygos veins. The current CCSVI diagnosis is based on Doppler sonography of extracranial and transcranial venous hemodynamics criteria. To date, prevalence estimates of CCSVI, provided by different groups using various imaging methods of assessment, vary widely from none to 100%. There is an urgent need to define and validate the spectrum of cranial/extracranial venous anomalies and to establish reliable, diagnostic gold-standard test(s). The potential usefulness of endovascular treatment for CCSVI in multiple sclerosis patients is still unknown. 相似文献
59.
J Ramanathan B M Sibai R Pillai J J Angel 《American journal of obstetrics and gynecology》1988,158(1):40-46
The purpose of the study was to evaluate the neuromuscular transmission defect in preeclamptic women receiving intravenous magnesium sulfate and to study the correlation of the degree of defect with serum magnesium and calcium levels. The study population included: group 1, 14 preeclamptic women receiving magnesium sulfate and undergoing induction of labor; group 2, six preeclamptic women studied in the postpartum period while receiving magnesium sulfate; and group 3, 10 normotensive women undergoing induction of labor. The neuromuscular transmission studies were performed with standard techniques before and during the administration of magnesium sulfate. During magnesium sulfate therapy patients in groups 1 and 2 showed abnormal responses characterized by an initial low-amplitude muscle action potential followed by a progressive increase in the amplitudes of the successive responses. There was significant correlation between the degree of the neuromuscular transmission defect and serum magnesium levels, serum calcium levels, and the magnesium/calcium ratio in groups 1 and 2. All studies were normal in group 3. The findings confirm the occurrence of abnormal neuromuscular transmission in preeclamptic women receiving magnesium sulfate, and the intensity of the defect correlates significantly with increased serum magnesium levels and decreased serum calcium levels. 相似文献
60.
We describe four obese, chronically hypertensive women presenting with antepartum pulmonary edema in whom invasive hemodynamic monitoring showed elevated wedge pressure, normal to high cardiac index, and normal systemic vascular resistance. Echocardiography revealed large chambers, thick walls, and increased left ventricular mass with normal systolic but abnormal diastolic function. These findings are indicative of intrinsic volume overload occurring in the presence of impaired left ventricular relaxation, a combination resulting in high filling pressures and pulmonary congestion. Diuretic therapy is indicated in this subset of patients, who could not be recognized by the usual clinical parameters such as history and physical examination, chest x-ray, and arterial blood gas. 相似文献