全文获取类型
收费全文 | 8452篇 |
免费 | 609篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 214篇 |
儿科学 | 263篇 |
妇产科学 | 221篇 |
基础医学 | 997篇 |
口腔科学 | 211篇 |
临床医学 | 727篇 |
内科学 | 1839篇 |
皮肤病学 | 158篇 |
神经病学 | 405篇 |
特种医学 | 291篇 |
外国民族医学 | 1篇 |
外科学 | 1313篇 |
综合类 | 187篇 |
一般理论 | 20篇 |
预防医学 | 632篇 |
眼科学 | 202篇 |
药学 | 802篇 |
1篇 | |
中国医学 | 64篇 |
肿瘤学 | 553篇 |
出版年
2023年 | 85篇 |
2022年 | 241篇 |
2021年 | 374篇 |
2020年 | 234篇 |
2019年 | 336篇 |
2018年 | 366篇 |
2017年 | 260篇 |
2016年 | 288篇 |
2015年 | 310篇 |
2014年 | 405篇 |
2013年 | 519篇 |
2012年 | 694篇 |
2011年 | 718篇 |
2010年 | 383篇 |
2009年 | 292篇 |
2008年 | 462篇 |
2007年 | 418篇 |
2006年 | 408篇 |
2005年 | 334篇 |
2004年 | 293篇 |
2003年 | 300篇 |
2002年 | 232篇 |
2001年 | 138篇 |
2000年 | 124篇 |
1999年 | 102篇 |
1998年 | 52篇 |
1997年 | 36篇 |
1996年 | 33篇 |
1995年 | 31篇 |
1994年 | 33篇 |
1993年 | 25篇 |
1992年 | 50篇 |
1991年 | 42篇 |
1990年 | 54篇 |
1989年 | 37篇 |
1988年 | 31篇 |
1987年 | 28篇 |
1986年 | 28篇 |
1985年 | 30篇 |
1984年 | 22篇 |
1983年 | 24篇 |
1982年 | 22篇 |
1979年 | 19篇 |
1978年 | 22篇 |
1977年 | 16篇 |
1976年 | 19篇 |
1975年 | 15篇 |
1974年 | 14篇 |
1973年 | 17篇 |
1972年 | 11篇 |
排序方式: 共有9101条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Mosaad A M Abou-Seif Mohammad M El-Naggar Mohammad El-Far Mohsen Ramadan Nivin Salah 《Clinical chemistry and laboratory medicine》2003,41(7):926-933
The formation of superoxide partially accounts for the well-known oxygen enhancement of radiation-induced biochemical changes and cell damage. Radioprotective effects of copper (II), manganese (IV) or vanadium (IV) complexes, of superoxide dismutase-mimetic activity, on body weight, survival rate and some biochemical parameters in pre-treated irradiated, untreated irradiated and treated non-irradiated female albino rats have been studied 24 h after whole body gamma-irradiation at a dose level of 6 Gy. Survival time, body weight, red blood cell (RBC) and white blood cell (WBC) counts, hemoglobin (Hb) concentration, percentage of hematocrit (Hct%), reduced glutathione (GSH), serum total protein, albumin, globulin (G), blood urea, creatinine and cholesterol were estimated, as well as the activities of blood superoxide dismutase (SOD), glutamate-oxaloacetic (GOT) and glutamate-pyruvic (GPT) transaminases, and alkaline phosphatase were assessed. A significant decline was shown in body weight, survival rate, the mean values of RBC and WBC counts, Hb and Hct percentages, and GSH concentration, as well as blood SOD activity, in whole body gamma-irradiated rats compared with the control non-irradiated rat group. The mean activity values of alkaline phosphatase, GOT and GPT, as well as the average values of blood urea, creatinine, total cholesterol, total protein and globulin were significantly elevated, while the average values of albumin and the albumin/globulin ratio were decreased in gamma-irradiated rats compared with the corresponding values of the normal control rat group. Pretreatment of rats with either manganese or vanadium complexes resulted in a significant increase in survival rate and body weight over that of the non-treated irradiated rat group. Pretreatment of rats with copper (II), manganese (IV) or vanadium (IV) complexes caused a significant increase in RBC and WBC counts, Hb concentration, HCt (%), GSH content and SOD activity in blood when compared to the irradiated rat group without treatment. The administration of copper (II), manganese (IV) or vanadium (IV) complexes prior to irradiation exposure resulted in a significant decrease in GOT and GPT activities in addition to blood urea, creatinine, cholesterol, globulin and total protein contents, while each complex exhibited a significant increase in plasma alkaline phosphatase, albumin, and the albumin/globulin ratio compared to the untreated irradiated rat group. Administration of vanadium (IV), manganese (IV) or copper (II) complexes in non-irradiated rats caused a significant increase in SOD activity without changing other biochemical parameters compared with the corresponding values of the normal control rat group. We conclude that these metallo-elements, particularly manganese (IV) and vanadium (IV) complexes of 2-methylaminopyridine, have radiation protection and radiation recovery. Furthermore, these metal complexes offer a new approach to overcome the pathological effects of ionizing radiation and suggest their use as a physiological approach to preventing or perhaps predominantly facilitating recovery from radiation injury. 相似文献
6.
15 Years in surgical management of pulmonary hydatidosis. 总被引:1,自引:0,他引:1
Raafat I Shalabi Adel K Ayed Morsi Amin 《Annals of thoracic and cardiovascular surgery》2002,8(3):131-134
OBJECTIVES: Echinococcosis remains an endemic surgical problem in countries where sheep and cattle raising is carried out, particularly in many Mediterranean countries. This study aims to evaluate the management of different presentations of pulmonary hydatidosis and their outcome over 15 years. DESIGN: Retrospective study.Setting: Thoracic surgical department, Chest Diseases Hospital, Kuwait. PATIENTS: Sixty patients operated upon for hydatid disease were evaluated pre- and post- operatively; 35 males, 25 females with a mean age of 28.4 years. Most patients were investigated by laboratory, serological and radiological studies. Different surgical techniques were used to remove the hydatid cyst from the lung. RESULTS: The most common presenting symptoms were cough (41 patients), and 12 patients were asymptomatic. Chest X-ray showed a rounded shadow in 42 patients; 19 cases were of vigorous size >10 cm. Thoracotomy was done in 57 patients; two chest wall cases were managed by minimal skin incision and enucleation, one hydatid cyst of the heart was approached through a median sternotomy. The mean hospital stay was 9 days. Postoperative complications occurred in 9 patients; prolonged air leak in 4 patients, pleural effusion in 3, pneumothorax, and wound infection in one patient each. One patient (65 years old) died on the 6th post-operative day most probably from pulmonary embolism. In a follow-up period of 2-15 years, 4 recurrences have been noted. CONCLUSION: Surgical excision of pulmonary hydatidosis with maximum preservation of the lung parenchyma is the main stay of treatment. 相似文献
7.
Cough and paradoxical vocal fold motion 总被引:8,自引:0,他引:8
Kenneth W. Altman MD PhD C. Blake Simpson MD Milan R. Amin MD Mona Abaza MD Ron Balkissoon MD Roy R. Casiano MD 《Otolaryngology--head and neck surgery》2002,127(6):501-511
OBJECTIVES: The differential diagnosis and treatment of patients with chronic cough, paradoxical vocal fold motion, and disordered breathing can be a challenge to most practicing otolaryngologists. Tracheobronchial (ie, asthma, bronchitis, and tracheal stenosis), laryngeal (ie, vocal fold paralysis and neoplasms), and rhinologic (ie, allergies and rhinosinusitis) etiologies are commonly diagnosed and treated effectively. However, occasionally one is faced with patients who are refractory to medical treatment and have no obvious rhinologic, laryngeal or pulmonary cause. STUDY DESIGN AND SETTING: We conducted a review of the literature. METHODS: We present a thorough review of the current medical literature exploring the complex neurologic mechanisms involved in the production of cough and the relationship between gastroesophageal reflux disease, vagal neurapathy, and paradoxical vocal fold motion. RESULTS: The diagnosis and successful treatment of chronic cough can be complex. It requires a thorough understanding of the neurologic mechanisms behind cough excitation and suppression. Successful treatment strategies include aggressive management of the patient's reactive airway disease, gastroesophageal reflux disease, and, in select cases, paradoxical vocal fold motion. This may involve a well-coordinated effort among pulmonologists, otolaryngologists, gastroenterologists, and speech pathologists. CONCLUSION: Gastroesophageal reflux disease, vagal neuropathy, and paradoxical vocal fold motion are additional causes of chronic cough and disordered breathing that need to be considered, in the absence of obvious laryngotracheal and/or rhinologic pathology. A high index of suspicion is essential in making the diagnosis and formulating an effective multidisciplinary treatment plan for these patients. 相似文献
8.
9.
10.
Ziprasidone (Geodone), a novel atypical antipsychotic agent, is recently approved for the treatment of schizophrenia. It undergoes extensive metabolism in preclinical species and humans after oral administration, and only a very small amount of administered dose is excreted as unchanged drug. In vitro studies using human liver microsomes have shown that the oxidative metabolism of ziprasidone is mediated primarily by CYP3A4. However, coadministration of ziprasidone with ketoconazole, a CYP3A4 inhibitor, showed only a modest increase in its exposure. Therefore, in vitro metabolism of ziprasidone was investigated in hepatic cytosolic fractions to further understand its clearance mechanisms in preclinical species and humans. The major metabolite from incubation of ziprasidone in cytosolic fractions of rat, dog, and human was characterized by liquid chromatography-tandem mass spectrometry and found to be the product of reductive cleavage. Derivatization and hydrogen/deuterium exchange were used to deduce that the addition of two hydrogen atoms had occurred at the benzisothiazole moiety. Further studies to determine the enzyme involved in the formation of this metabolite are currently in progress. The identification of this novel metabolite in cytosol has clarified the clearance mechanism of ziprasidone in humans and preclinical species. 相似文献