全文获取类型
收费全文 | 4392篇 |
免费 | 499篇 |
国内免费 | 97篇 |
专业分类
耳鼻咽喉 | 67篇 |
儿科学 | 99篇 |
妇产科学 | 41篇 |
基础医学 | 290篇 |
口腔科学 | 29篇 |
临床医学 | 756篇 |
内科学 | 396篇 |
皮肤病学 | 31篇 |
神经病学 | 629篇 |
特种医学 | 61篇 |
外科学 | 365篇 |
综合类 | 624篇 |
现状与发展 | 1篇 |
预防医学 | 352篇 |
眼科学 | 57篇 |
药学 | 535篇 |
13篇 | |
中国医学 | 432篇 |
肿瘤学 | 210篇 |
出版年
2024年 | 40篇 |
2023年 | 129篇 |
2022年 | 196篇 |
2021年 | 277篇 |
2020年 | 282篇 |
2019年 | 253篇 |
2018年 | 259篇 |
2017年 | 227篇 |
2016年 | 196篇 |
2015年 | 172篇 |
2014年 | 276篇 |
2013年 | 306篇 |
2012年 | 260篇 |
2011年 | 268篇 |
2010年 | 216篇 |
2009年 | 197篇 |
2008年 | 207篇 |
2007年 | 190篇 |
2006年 | 189篇 |
2005年 | 148篇 |
2004年 | 105篇 |
2003年 | 83篇 |
2002年 | 90篇 |
2001年 | 73篇 |
2000年 | 59篇 |
1999年 | 37篇 |
1998年 | 35篇 |
1997年 | 26篇 |
1996年 | 28篇 |
1995年 | 27篇 |
1994年 | 21篇 |
1993年 | 27篇 |
1992年 | 13篇 |
1991年 | 16篇 |
1990年 | 6篇 |
1989年 | 14篇 |
1988年 | 7篇 |
1987年 | 7篇 |
1986年 | 5篇 |
1985年 | 8篇 |
1984年 | 3篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 6篇 |
1979年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有4988条查询结果,搜索用时 15 毫秒
991.
Manfred Gerlach Wieland Gsell Johannes Kornhuber Kurt Jellinger Verena Krieger Felix Pantucek Reinhard Vock Peter Riederer 《Brain research》1996,741(1-2)
Functional models of the circuitry of the basal ganglia have recently been proposed to account for the vast spectrum of motor disorders associated with the loss of anatomical or neurochemical integrity within the basal ganglia. On the basis of these hypothetical models, hypokinetic disorders such as Parkinson's disease, are thought to be associated with excessive tonic and phasic inhibition of the output from the basal ganglia to the thalamus. In the present study we have attempted to determine the validity of the proposed model by measuring neurochemical markers of inhibitory and excitatory neurotransmission in post mortem human brain tissue. We have determined the concentrations of the excitatory neurotransmitters aspartate/glutamate and of the inhibitory neurotransmitter GABA in 18 relevant regions of the thalamocortical circuits of the basal ganglia of patients who had manifested Parkinsonian symptoms, and compared them with controls of individuals who had died without any history of neurological or psychiatric disorders and had no neuropathological abnormalities. Additionally, the receptor subtype for the excitatory amino acidN-methyl-d-aspartate (NMDA) was studied in the same brain tissue in which neurotransmitter concentrations had been analysed as neurochemical markers of post-synaptic excitatory neurotransmission. In patients who had manifested Parkinsonian symptoms, glutamate and aspartate levels were found to be unchanged in all examined brain regions. In contrast, the binding of [3H]MK-801, which identifies the NMDA receptor, was reduced in the head (−42%) and body (-38%) of the caudate nucleus. In Parkinsonian patients, GABA levels were diminished by 36% in the centromedial thalamus, compared to control values. These results do not confirm the changes in neurotransmitter concentrations predicted according to the model, although we cannot rule out that the predicted changes might have been observed if the Parkinsonian group had been further subdivided into groups diagnosed on the basis of the patients' clinical picture (akinetic-rigid, tremor-dominant, equivalent type) and compared with the control group. 相似文献
992.
This report examines the comorbidity among three key symptoms associated with suicidal intent, namely hopelessness, depression and unusual thinking. A total of 97 out-patients with suicidal thoughts were assessed using the Beck Hopelessness Scale, the anxious depression and unusual thinking factor scales of the Derogatis Symptom Checkhst-90, and the Beck Scale for Suicide Ideation. It was found that, in considering the interaction between key presenting symptoms, the combination of hopelessness and unusual thinking (which consisted of symptoms such as ‘trouble concentrating’ and ‘mind going blank’) was the strongest predictor of the seriousness of current suicidal inclinations. 相似文献
993.
34例女性生殖器畸形病人术前心身特点及相关性研究 总被引:10,自引:2,他引:8
使用症状自评量表(SCL-90)、艾森克人格问卷(EPQ)、医学应对调查表(MCMQ)、社会支持调查表(PSSS)对女性生殖器畸形患者作心身特点及相关因素研究。结果显示:①患者心身状况明显差于正常女性群体;②患者的人格特征与正常女性存在差异;③应对方式“面对”与患者心身症状呈负相关,但无统计学显著性;“屈服”与患者心身症状呈正相关,且与总分、抑郁、焦虑、恐怖、偏执、其它有高度相关;④社会支持对改善此类病人的心身症状的作用不大。 相似文献
994.
Shin-Ichi Morishita Masamichi Shoji Yasuhiro Oguni Yasuharu Hirai Chishio Sugimoto Chihiro Ito 《Phytotherapy research : PTR》1993,7(2):179-184
Traditional medicines, such as Gosya-jinki-gan (Niu-Che-Shen-Qi-Wan) extract preparation (KJE), “Kyushin” (KY–2) and “Reiousan” (R–03) were studied to determine their effects on sexual and learning behaviour in mice subjected to chronic “hanging stress”. Drugs were given orally once a day for 14 days, and sexual (licking, mounting and intromission) and learning (memory retrieval and memory extinction) behaviour were observed. KJE and R–03 protected mice against the stress-induced decrease of licking, mounting and intromission behaviour, and increases of acceleration of memory loss and failure of memory retrieval. KY–2 protected mice against stress-induced decrease of licking and intromission behaviour, and increases of acceleration of memory loss and failure to retrieve memory. These results suggest that these drugs have protective effects against chronically exhausted states. 相似文献
995.
E. OMENAAS P. BAKKE G. E. EIDE S. ELSAYED A. GULSVIK 《Clinical and experimental allergy》1995,25(8):682-689
Background: The importance of total serum IgE level on lung function impairment has not been established in a general population. Objective: The aim of this cross-sectional community study was to examine the relationship between total serum IgE and level of lung function in adults, and whether this relationship differed by sex, age, smoking habits or by respiratory symptom and disease status. Methods: A stratified random sample of 18–73 year old adults from the general population were invited to spirometry and serum analyses of total and specific IgE. Of 1512 subjects invited, 82% met and performed complete examinations. Results: Increasing level of total serum IgE was related to reduced lung function (P<0.01) given as sex, age, and height standardized residuals of one second forced expiratory volume (SFEV1). Subjects with total serum IgE in the highest vs the lowest tertile had a mean SFEV1 of -0.58 vs -0.28, corresponding to age and height adjusted FEV1 differences of 120 and 150mL in women and men, respectively. The relationship between IgE and lung function impairment did not differ significantly by sex, age or smoking habits. In subjects with obstructive’lung disease increasing level of total serum IgE was more negatively associated with lung function level than in subjects with respiratory symptoms alone. No relationship was observed in a symptomatic subjects. This was confirmed in a multiple linear regression analysis adjusting for sex, age, smoking habits and lifetime smoking consumption showing that SFEV1 was predicted by an interaction between total serum IgE level and symptom and disease status (P < 0.01). This interaction remained after excluding subjects (n= 105) having specific IgE antibodies. Conclusion: Increasing total serum IgE level was associated with progressively lower lung function in a general adult population after taking other predictors of impaired Spiro metric lung function into account, though dependent on the subjects’respiratory symptom and disease status. Variation in prevalences of respiratory symptoms and obstructive lung disease in previous examined populations may thus explain conflicting observations of the association between total IgE and airflow impairment. 相似文献
996.
目的探讨足剂量雾化吸入布地奈德对急性喘息性支气管炎患儿临床症状的影响。方法选择2017年10月至2019年3月我院收治的60例急性喘息性支气管炎患儿,随机分为观察组和对照组各30例。两组均进行常规对症治疗,基于此,对照组雾化吸入低剂量布地奈德,观察组雾化吸入足剂量布地奈德。比较两组患儿治疗后临床症状改善情况、肺功能指标及不良反应情况。结果治疗后,观察组的咳嗽缓解时间、咳嗽消失时间、肺部哮鸣音消失时间、气促缓解时间均短于对照组(P<0.05);两组的FVC、FEV1及PEF均上升,且观察组的FVC、FEV1及PEF高于对照组(P均<0.05)。两组的不良反应发生率比较无统计学差异(P>0.05)。结论足剂量雾化吸入布地奈德治疗急性喘息性支气管炎的效果确切,可快速改善患儿的临床症状,增强其肺功能,且安全性高,值得推广应用。 相似文献
997.
Joseph Yusin Vivian Wang Susanne M. Henning Jieping Yang Chi-Hong Tseng Gail Thames Irina Arnold David Heber Ru-Po Lee Laura Sanavio Yajing Pan Tianyu Qin Zhaoping Li 《Nutrients》2021,13(4)
Patients exposed to pollutants are more likely to suffer from allergic rhinitis and may benefit from antioxidant treatment. Our study determined if patients diagnosed with grass-induced allergic rhinitis could benefit from broccoli sprout extract (BSE) supplementation. In total, 47 patients were confirmed with grass-induced allergic rhinitis and randomized to one of four groups: group 1 (nasal steroid spray + BSE), group 2 (nasal steroid spray + placebo tablet), group 3 (saline nasal spray + BSE) and group 4 (saline nasal spray + placebo tablet). Peak Nasal Inspiratory Flow (PNIF), Total Nasal Symptoms Scores (TNSS) and nasal mucus cytokine levels were analyzed in samples collected before and after the 3-week intervention. Comparing before and after the intervention, PNIF improved significantly when comparing Groups 1 and 2, vs. placebo, at various time points (p ≤ 0.05 at 5, 15, 60 and 240 min) following nasal challenge, while TNSS was only statistically significant at 5 (p = 0.03), 15 (p = 0.057) and 30 (p = 0.05) minutes. There were no statistically significant differences in various cytokine markers before and after the intervention. Combining nasal corticosteroid with BSE led to the most significant improvement in objective measures. 相似文献
998.
M. Paleker Y. A Tembo M-A. Davies H. Mahomed D. Pienaar S. A. Madhi K. McCarthy 《Public Health Action》2021,11(2):58
Asymptomatic COVID-19 may contribute significantly to the pandemic trajectory based on global biological, epidemiological and modelling evidence. A retrospective analysis was done to determine the proportion of asymptomatic COVID-19 in the workplace during the lockdown period from 27 March to 31 May 2020. We found that nearly 45% of cases were asymptomatic at the time of the first test. This high proportion of asymptomatic COVID-19 cases has implications for interventions, such as enforcing quarantine of all close contacts of COVID-19 cases regardless of symptoms. 相似文献
999.
Chi-Hsien Chen Perng-Jy Tsai Ya-Fen Wang Chih-Hong Pan Po-Chen Hung Jiune-Jye Ho Diahn-Warng Perng Benoit Nemery Yue Leon Guo 《Scandinavian journal of work, environment & health》2021,47(1):62
Objectives:Fiberglass-reinforced plastics (FRP) manufacturing has been related to cases of severe airway obstruction and elevated risk of respiratory mortality. But the specific job content risk is not clear. This study evaluated the respiratory health effects of the FRP lamination process.Methods:A questionnaire was used to evaluate respiratory symptoms of workers in two yacht-building plants. Pre-shift (07:30–08:30 hours) and post-shift (17:00–18:00 hours) lung function was measured, while post-shift induced sputum was collected on the first day of the week. The participants were grouped into FRP laminators and non-laminators. Linear and logistic regression was used to investigate the effects of the lamination process on lung function.Results:Laminators had a higher prevalence of chronic cough, lower pre-shift forced expiratory volume in first second (FEV1) and FEV1/force vital capacity (FVC) (-3.3% and -1.5%), lower post-shift FVC and FEV1 (-3.6% and -4.9%), and larger post-shift reduction of FVC (-2.1%) compared to non-laminators. The laminators also had higher risk of early obstructive and overall (obstructive plus restrictive) lung function impairment, and post-shift reduction of FVC >10% [odds ratio (OR) 5.98, 4.98, and 3.87, respectively). They also had higher percentages of neutrophils and lymphocytes in the induced sputum.Conclusion:Laminators should undergo regular check-ups of respiratory symptoms and lung function. Further toxicologic studies are warranted to identify the specific causal agent in the FRP lamination process. 相似文献
1000.
Beyond symptomatic relief for chemotherapy‐induced peripheral neuropathy: Targeting the source 下载免费PDF全文
Jiacheng Ma PhD Annemieke Kavelaars PhD Patrick M. Dougherty PhD Cobi J. Heijnen PhD 《Cancer》2018,124(11):2289-2298
Chemotherapy‐induced peripheral neuropathy (CIPN) is a serious adverse side effect of many chemotherapeutic agents, affecting >60% of patients with cancer. Moreover, CIPN persists long into survivorship in approximately 20% to 30% of these patients. To the authors' knowledge, no drugs have been approved to date by the US Food and Drug Administration to effectively manage chemotherapy‐induced neuropathic pain. The majority of the drugs tested for the management of CIPN aim at symptom relief, including pain and paresthesia, yet are not very efficacious. The authors propose that there is a need to acquire a more thorough understanding of the etiology of CIPN so that effective, mechanism‐based, disease‐modifying interventions can be developed. It is important to note that such interventions should not interfere with the antitumor effects of chemotherapy. Mitochondria are rod‐shaped cellular organelles that represent the powerhouses of the cell, in that they convert oxygen and nutrients into the cellular energy “currency” adenosine triphosphate. In addition, mitochondria regulate cell death. Neuronal mitochondrial dysfunction and the associated nitro‐oxidative stress represent crucial final common pathways of CIPN. Herein, the authors discuss the potential to prevent or reverse CIPN by protecting mitochondria and/or inhibiting nitro‐oxidative stress with novel potential drugs, including the mitochondrial protectant pifithrin‐μ, histone deacetylase 6 inhibitors, metformin, antioxidants, peroxynitrite decomposition catalysts, and anti‐inflammatory mediators including interleukin 10. This review hopefully will contribute toward bridging the gap between preclinical research and the development of realistic novel therapeutic strategies to prevent or reverse the devastating neurotoxic effects of chemotherapy on the (peripheral) nervous system. Cancer 2018;124:2289‐98 . © 2018 American Cancer Society. 相似文献