全文获取类型
收费全文 | 5792篇 |
免费 | 296篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 77篇 |
儿科学 | 228篇 |
妇产科学 | 175篇 |
基础医学 | 679篇 |
口腔科学 | 127篇 |
临床医学 | 392篇 |
内科学 | 1123篇 |
皮肤病学 | 137篇 |
神经病学 | 325篇 |
特种医学 | 108篇 |
外科学 | 1027篇 |
综合类 | 184篇 |
一般理论 | 3篇 |
预防医学 | 493篇 |
眼科学 | 179篇 |
药学 | 527篇 |
中国医学 | 34篇 |
肿瘤学 | 291篇 |
出版年
2023年 | 58篇 |
2022年 | 101篇 |
2021年 | 253篇 |
2020年 | 161篇 |
2019年 | 190篇 |
2018年 | 231篇 |
2017年 | 148篇 |
2016年 | 186篇 |
2015年 | 198篇 |
2014年 | 228篇 |
2013年 | 302篇 |
2012年 | 478篇 |
2011年 | 456篇 |
2010年 | 261篇 |
2009年 | 189篇 |
2008年 | 289篇 |
2007年 | 276篇 |
2006年 | 260篇 |
2005年 | 263篇 |
2004年 | 219篇 |
2003年 | 208篇 |
2002年 | 200篇 |
2001年 | 82篇 |
2000年 | 73篇 |
1999年 | 70篇 |
1998年 | 40篇 |
1997年 | 26篇 |
1996年 | 18篇 |
1995年 | 25篇 |
1994年 | 19篇 |
1993年 | 24篇 |
1992年 | 48篇 |
1991年 | 40篇 |
1990年 | 34篇 |
1989年 | 37篇 |
1988年 | 40篇 |
1987年 | 25篇 |
1986年 | 28篇 |
1985年 | 29篇 |
1984年 | 36篇 |
1983年 | 25篇 |
1982年 | 16篇 |
1981年 | 22篇 |
1980年 | 26篇 |
1979年 | 9篇 |
1977年 | 16篇 |
1976年 | 19篇 |
1972年 | 10篇 |
1966年 | 10篇 |
1931年 | 8篇 |
排序方式: 共有6109条查询结果,搜索用时 390 毫秒
71.
Neeraj Mahindroo Zabeer Ahmed Asha Bhagat Kasturi Lal Bedi Ravi Kant Khajuria Vijay Kumar Kapoor Kanaya Lal Dhar 《Medicinal chemistry research》2005,14(6):347-368
The series of vasicine (1) analogues, an alkaloid from Adhatoda vasica Nees., were synthesized with changes in A, B or C rings. Compounds 13-19 were evaluated for in vitro bronchodilatory activity using isolated guinea pig tracheal chain. Compounds 3-8 were also synthesized in good yields using microwave-mediated synthesis under solvent free conditions. Compounds 5 and 8 with seven-member C ring were more active than etofylline and caused 100% relaxation of both the histamine and acetycholine
pre-contracted guinea pig tracheal chain. The structure-activity relationship studies showed that the quinazoline and oxo
functionalities were essential for activity. The compounds without C ring and instead having aliphatic and phenyl substitutions
in B ring showed relaxation against histamine pre-contracted tracheal chain only, 2-methyl substituted analogues, 12 and 13, being most active with 100% relaxation effect. 相似文献
72.
Dhanalakshmi Angappan Jitendra K. Sahu Prahbhjot Malhi Pratibha Singhi 《European journal of paediatric neurology》2019,23(1):136-142
West syndrome is a distinct, infantile onset, epileptic encephalopathy, associated with poor neurodevelopmental outcome. The present study was designed as a randomized, open-label, pilot study to evaluate the safety, feasibility, and effectiveness of oral zonisamide therapy in comparison with adrenocorticotropic hormone therapy in infants with West syndrome. Thirty infants with West syndrome were randomized to receive treatment with either synthetic, intramuscular adrenocorticotropic hormone (30–60 IU) or oral zonisamide (4–25 mg/kg/day). The study participants had a long treatment lag and preponderance of male sex (90%). The primary effectiveness outcome measure was the cessation of epileptic spasms at 2 weeks of initiation of therapy and persistent till 6 weeks as per West Delphi consensus statement recommendations. Comparison of efficacies of zonisamide versus adrenocorticotropic hormone was as following: the cessation of epileptic spasms (27% vs. 40%, p = 0.70), resolution of hypsarrhythmia at 14 days (20% vs. 33%, p = 0.68) and resolution of hypsarrhythmia at 6 weeks (36% vs. 71%, p = 0.14). Overall, the study observed a poor efficacy of both adrenocorticotropic hormone and zonisamide therapy, which is probably due to long treatment lag and a high proportion of structural aetiology. However, oral zonisamide appeared to be safe and tolerable in the study. 相似文献
73.
74.
Sachin Malik Suroor A. Khan Priya Ahuja Satish K. Arya Shikha Sahu Kapendra Sahu 《Medicinal chemistry research》2013,22(12):5633-5653
Malaria is the leading infectious disease found in humans, affecting third-world countries. Worldwide, more than two billion people are at risk of malaria, with about 500 million clinical cases of malaria each year and one million deaths. In this focused review, an effort has been made to summarize the reactions of singlet oxygen with organic substrates, their stereoselectivity, stereospecificity and utilization in generating dioxetanes and endoperoxides. The study of production and reactivity indications of this exceptional molecule has emerged as a rich and diverse area in the synthesis of antimalarials like artemisinin and its semisynthetic derivatives, structurally simple 1,2,4-trioxanes, sesquiterpene isonitriles, synthetic cyclic, and other acyclic peroxides. Artermisinin, a mainstay in antimalarial drug therapy, meets the dual challenge posed by drug-resistant parasites and rapid advancement of lethal malarial threat. The cardinal mechanism of peroxidation and ring closure in its production are induced by singlet oxygen and acid. Moreover, its complex structure restricts the complete chemical synthesis of artemisinin. Consequently, the limited availability coupled with increasing demand for artemisinin has paved the way for the preparation of synthetic alternatives of artemisinin and its derivatives. Likewise, past evidence of the structure–activity relationship indicate the importance of singlet oxygen in antimalarial drug synthesis. It is anticipated that this compendium on the chemistry of singlet oxygen will be of use to organic/medicinal chemists and pharmacologists working on antimalarial drug development. 相似文献
75.
A.K. Bartella A.-K. Sander M. Kamal J. Steegmann A. Kloss-Brandstätter J. Teichmann F. Hölzle B. Lethaus 《The British journal of oral & maxillofacial surgery》2018,56(4):322-326
Despite improvements in the management of patients in critical care, about 3% patients who have an operation with curative intent for oral squamous cell carcinoma (SCC) do not survive their stay in hospital. Our aim was to assess the risk factors for postoperative death that were independent of the stage of the cancer, or the age and sex of the patients. We screened 4760 consecutive inpatients at a maxillofacial tertiary care centre from 2011 to 2016, and 34 of them had died within the first three months after operation. We matched them with a further 34 patients with the same TNM stage, age, and sex. General personal and clinical data and preoperative laboratory values were screened, and we applied a Charlson Comorbidity Score (for anaesthetic risk) for each group. Patients’ mean (SD) age was 66 (12) years old. There was no significant difference in sex (p = 1), age (p = 0.718), or TNM classification. Those who died after operation had significantly more renal (p = 0.027) and gastrointestinal (p = 0.006) diseases, but cardiac diseases (p = 0.468) and diabetes mellitus (p = 1) were not significant risk factors in themselves. Patients who died postoperatively had significantly worse risk scores (p = 0.001) overall. The most common causes of death were septic shock (n = 10) and acute cardiac (n = 9) or respiratory failure (n = 7). Our findings suggested that general diseases were not intrinsically a contraindication for operation with curative intent. The Charlson Comorbidity Score helped to detect potentially fatal courses and could be useful in the preoperative assessment of patients whose general health is not good. 相似文献
76.
77.
Kamel Sadat M.D. Hari Prakash Diddi M.B.B.S. Berthold Klas B.S. Ayman Haj Asaad M.D. Elif İjlal Çekirdekçi M.D. Aylin Sungur M.D. Selvin Sudhakar M.D. Matthew Cain M.D. Arshad Kamal M.D. Navin C. Nanda M.D. 《Echocardiography (Mount Kisco, N.Y.)》2013,30(10):1227-1231
Hypertrophic cardiomyopathy (HCM) is the most common genetically transmitted cardiomyopathy. In patients resistant to medical management, myectomy is the surgical procedure of choice to reduce the symptoms of left ventricular outflow obstruction. Two‐dimensional transesophageal echocardiography (2DTEE) has become part of the operative procedure by decreasing the incidence of postoperative complications. However, because of the three‐dimensional geometry of left ventricular outflow tract, it is unable to comprehensively assess the location and severity of the obstruction and to provide accurate guidance during myectomy. In this study, 10 patients with HCM underwent live/real time three‐dimensional transesophageal echocardiography (3DTEE) intra‐operatively to measure the volume of the resected septum. This volume correlated well with the volume of the resected septal muscle directly obtained using a graduating cylinder containing water (r = 0.9, P < 0.000). 3DTEE may be potentially used as an adjunct to guide the surgeon in performing an adequate myectomy with a lower incidence of residual obstruction and complications such as an iatrogenic ventricular septal defect. 相似文献
78.
Sheikh Rayees Rohit Sharma Gurdarshan Singh Ishtiyaq Ahmad Najar Amarinder Singh Dastagir Basheer Ahamad Subash Chander Sharma Manoj Kumar Tikoo Vijay Kumar Gupta Payare Lal Sangwan Surjeet Singh Surinder Koul Rakesh Kamal Johri 《Environmental toxicology and pharmacology》2013,35(2):347-359
An efflux pump inhibitor, SK-20 (5-(3,4-methylenedioxyphenyle)-4 ethyl-2E,4E-pentadienoic acid piperidide), was assessed for its toxicity at three different pharmacological profiles: acute, sub-acute and general pharmacology with pharmacokinetics. In acute study, the SK-20 was found safe up to a dose of 2000 mg/kg (b.wt.); and at sub-acute, dosages of 50 and 100 mg/kg (b.wt.) were found to be safe. However, dosages of 200 mg or above per kg (b.wt.) showed some morphological alterations in cellular architecture of both liver and kidneys in both sexes, viz., mild vascular congestion along with sporadic hemorrhages and infiltration into renal and hepatic parenchyma by mononucleate cell. General pharmacological studies did not result into any alterations in analgesic, convulsions, rectal temperatures and in the rhythm or the rate of the intestinal motility or the secretion of the bile. While the respiratory and the cardiac rate remained normal, the only parameter to show was the blood pressure, which at all the doses tested, showed a tendency toward reduction. Characteristically, the SK-20 at all doses influenced pentobarbital-induced hypnosis positively and negatively to spontaneous motor activity in a dose dependent manner. Pharmacokinetics of SK-20 revealed it to have retention time at 10.2 min and half life 2.47 h. 相似文献
79.
80.
Priyadarshi Soumyaranjan Sahu Jyotsna Seepana Sudarsini Padela Abani Kanta Sahu Swarna Subbarayudu Ankur Barua 《Revista do Instituto de Medicina Tropical de S?o Paulo》2014,56(3):253-258
Neurocysticercosis (NCC) is one of the major causes of childhood seizures
in developing countries including India and Latin America. In this study neurological
pediatric cases presenting with afebrile seizures were screened for anti-Cysticercus
antibodies (IgG) in their sera in order to estimate the possible burden of
cysticercal etiology. The study included a total of 61 pediatric afebrile seizure
subjects (aged one to 15 years old); there was a male predominance. All the sera were
tested using a pre-evaluated commercially procured IgG-ELISA kit (UB-Magiwell
Cysticercosis Kit ™). Anti-Cysticercus antibody in serum was positive in 23 of 61 (37.7%)
cases. The majority of cases with a positive ELISA test presented with generalized
seizure (52.17%), followed by complex partial seizure (26.08%), and simple partial
seizure (21.73%). Headaches were the major complaint (73.91%). Other presentations
were vomiting (47.82%), pallor (34.78%), altered sensorium (26.08%), and muscle
weakness (13.04%). There was one hemiparesis case diagnosed to be NCC. In this study
one child without any significant findings on imaging was also found to be positive
by serology. There was a statistically significant association found between the
cases with multiple lesions on the brain and the ELISA-positivity (p
= 0.017). Overall positivity of the ELISA showed a potential cysticercal etiology.
Hence, neurocysticercosis should be suspected in every child presenting with afebrile
seizure especially with a radio-imaging supportive diagnosis in tropical developing
countries or areas endemic for taeniasis/cysticercosis. 相似文献