全文获取类型
收费全文 | 41909篇 |
免费 | 2361篇 |
国内免费 | 104篇 |
专业分类
耳鼻咽喉 | 511篇 |
儿科学 | 1390篇 |
妇产科学 | 1027篇 |
基础医学 | 5682篇 |
口腔科学 | 1032篇 |
临床医学 | 3956篇 |
内科学 | 7632篇 |
皮肤病学 | 878篇 |
神经病学 | 4219篇 |
特种医学 | 1318篇 |
外国民族医学 | 1篇 |
外科学 | 5598篇 |
综合类 | 164篇 |
一般理论 | 23篇 |
预防医学 | 4198篇 |
眼科学 | 844篇 |
药学 | 2857篇 |
中国医学 | 108篇 |
肿瘤学 | 2936篇 |
出版年
2023年 | 331篇 |
2022年 | 414篇 |
2021年 | 793篇 |
2020年 | 625篇 |
2019年 | 769篇 |
2018年 | 1132篇 |
2017年 | 957篇 |
2016年 | 1093篇 |
2015年 | 1154篇 |
2014年 | 1321篇 |
2013年 | 1963篇 |
2012年 | 2737篇 |
2011年 | 2879篇 |
2010年 | 1553篇 |
2009年 | 1278篇 |
2008年 | 2058篇 |
2007年 | 2282篇 |
2006年 | 2098篇 |
2005年 | 2120篇 |
2004年 | 2021篇 |
2003年 | 1910篇 |
2002年 | 1781篇 |
2001年 | 752篇 |
2000年 | 740篇 |
1999年 | 694篇 |
1998年 | 358篇 |
1997年 | 302篇 |
1996年 | 258篇 |
1995年 | 241篇 |
1993年 | 179篇 |
1992年 | 402篇 |
1991年 | 380篇 |
1990年 | 403篇 |
1989年 | 359篇 |
1988年 | 351篇 |
1987年 | 329篇 |
1986年 | 353篇 |
1985年 | 354篇 |
1984年 | 284篇 |
1983年 | 247篇 |
1982年 | 174篇 |
1979年 | 278篇 |
1978年 | 185篇 |
1975年 | 173篇 |
1974年 | 222篇 |
1973年 | 211篇 |
1972年 | 227篇 |
1971年 | 184篇 |
1969年 | 209篇 |
1968年 | 179篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
a. lobrano k. blanchard t.l. abell a. minocha w. boone j. wyatt-ashmead † j. fratkin † c. subramony † a. wee jr ‡ g. di nardo § g. barbara § v. stanghellini § & r. de giorgio § 《Neurogastroenterology and motility》2006,18(2):162-167
BACKGROUND AND AIM: Severe dysautonomia may be secondary to viral infections, resulting in impaired autoimmune, cardiovascular, urinary and digestive dysfunction. Herein, we present a case of a 31-year-old white female patient who had severe gastroparesis related to autonomic failure following an episode of acute gastroenteritis. This seems to be the first report providing thorough assessment of the enteric and autonomic nervous system by analysis of full-thickness small intestinal biopsies, cardiovagal testing and autopsy. HOSPITAL COURSE: This patient affected by a severe gastroparesis was treated with antiemetics, prokinetics, analgesics and gastric electrical stimulation to control symptoms. Nutritional support was made using jejunal feeding tube and, in the final stage of disease, with total parenteral nutrition. Autonomic studies revealed minimal heart rate variability and a disordered Valsalva manoeuvre although the enteric nervous system and the smooth muscle layer showed a normal appearance. Hospital courses were complicated by episodes of bacteraemia and fungemia. Serum antiphospholipid antibodies were noted but despite anticoagulation, she developed a pulmonary embolism and shortly thereafter the patient died. Autopsy revealed acute haemorrhagic Candida pneumonia with left main pulmonary artery thrombus. Sympathetic chain analysis revealed decreased myelinated axons with vacuolar degeneration and patchy inflammation consistent with Guillain-Barre syndrome. The evaluation of the enteric nervous system in the stomach and small bowel revealed no evidence of enteric neuropathy or myopathy. CONCLUSION: A Guillain-Barre-like disease with gastroparesis following acute gastroenteritis is supported by physiological and autonomic studies with histological findings. 相似文献
22.
23.
Peter Chiba Barbara Tell Walter Jger Elisabeth Richter Manuela Hitzlera Gerhard Ecker 《Archiv der Pharmazie》1997,330(11):343-347
A series of 5-hydroxy and 5-benzyloxy analogs of the antiarrhythmic and multidrug resistance (MDR) modulating drug propafenone was synthesized and the MDR-modulating activity of the compounds was evaluated using a daunomycin efflux assay system. The key step of the synthesis is the selective reduction of the double bond in 1 without cleavage of the benzyl group thus leading to the phenol 3 . Alkylation with epichlorohydrine followed by nucleophilic epoxide ring opening gave the benzylated target compounds 5a–d . Subsequent cleavage of the benzyl group gave the 5-hydroxy analogs 6a–d . Structure activity relationship studies showed, that the 5-hydroxy derivates 6a–d fit the log P/log potency correlation line previously established for a series of propafenone analogs. In contrast, all four 5-benzyloxy analogs 5a–d showed almost identical EC50 values, independent of their log P value. 相似文献
24.
r. s. choung n. j. talley j. peterson m. camilleri d. burton w. s. harmsen † & a. r. zinsmeister † 《Neurogastroenterology and motility》2007,19(3):180-187
Itopride, a dopamine D2 antagonist and acetylcholinesterase inhibitor, significantly improved symptoms in patients with functional dyspepsia in one phase II randomized trial. However, the mechanisms by which itopride may improve symptoms are unknown. We aimed to compare the effects of two doses of itopride and placebo on gastric volumes, gastric emptying, small bowel transit and satiation in female and male healthy volunteers. Randomized, double-blind, placebo-controlled study evaluated gastric function before and after 7 days of itopride 100 mg (n = 16) or 200 mg (n = 15) or placebo (n = 15) t.i.d. Validated methods were used to study gastric accommodation (single photon emission computed tomography), gastric emptying and orocecal transit and satiation postnutrient challenge. The three arms were comparable with regard to age, gender and body mass index. There were no statistically significant effects of itopride on gastric emptying, orocecal transit, fasting gastric volume, maximum tolerated volume or aggregate symptom score with nutrient drink challenge. Postprandial (PP) change in gastric volume differed in the three groups (P = 0.019): 625[+/-28 (SEM)], 555(+/-26) and 512(+/-33) in placebo, itopride 100 and 200 mg groups, respectively. In healthy subjects, itopride reduced total PP gastric volume without accelerating gastric emptying or significantly altering gastric motor and sensory function in healthy individuals. 相似文献
25.
Cyclodextrin formulation of dorzolamide and its distribution in the eye after topical administration. 总被引:2,自引:0,他引:2
Hakon H Sigurdsson Einar Stefánsson Elínborg Gudmundsdóttir Thór Eysteinsson Margrét Thorsteinsdóttir Thorsteinn Loftsson 《Journal of controlled release》2005,102(1):255-262
Due to limited aqueous solubility of dorzolamide at physiologic pH, the pH of Trusopt eye drops (cont. 2% dorzolamide) has to be kept at about 5.65, and to increase the topical bioavailability of the drug from Trusopt the contact time of the drug with the eye surface is increased by increasing the viscosity of the eye drops to 100 cps. This low pH and high viscosity can lead to local irritation. In this study, dorzolamide hydrochloride was formulated as 2% and 4% low viscosity solutions (viscosity 3 to 5 cps) containing randomly methylated beta-cyclodextrin at pH 7.45. These formulations were evaluated in rabbits. The animals were sacrificed at various time points after topical administration of the drug and the dorzolamide concentration determined in the different parts of the eye. Trusopt was used as a reference standard. The topical availability of dorzolamide from the cyclodextrin-containing eye drops appeared to be comparable to that from Trusopt and the drug reached retina and optic nerve to give measurable concentrations for at least 8 h after administration of the eye drops. 相似文献
26.
Henrik J. O. Bengtsson M.D. Albert E. A. Broomé M.D. Ph.D. Ulf Rimér M.D. 《World journal of surgery》1986,10(3):510-514
The use of a vascularized jejunal patch for the reconstruction of bile duct injuries is presented. The method has been used in 1 patient with a common bile duct stricture and in 1 patient with a noncircumferential bile duct defect. The procedure has the advantages of technical simplicity, primary mucosal coverage, lasting elasticity, and minimal risk for stricture formation.
Resumen Se presenta el uso de un parche vascularizado de yeyuno para la reconstrucción de lesiones del canal colédoco. Se reseca un segmento móvil del yeyuno lo suficientemente amplio para cubrir el defecto, asegurándose de que existe buena irrigación para el segmento, visualizando los vasos por transiluminación con luz ordinaria. La continuidad del intestino es restablecida mediante anastomosis término-terminal. Se utiliza la parte mesentérica del segmento intestinal, el cual es ascendido por vía retrocólica. Se sutura mucosa con mucosa con una sola capa de puntos separados de ácido poliglicólico 5-0. Se coloca un tubo-en-T para drenaje, el cual es retirado a las 6 semanas. El método ha sido utilizado en un caso de estenosis del colédoco y en un caso con un defecto circunferencial del mismo canal biliar. El procedimiento tiene la ventaja de la simplicidad técnica, la cobertura primaria de la mucosa, la elasticidad permanente y un mínimo riesgo de que se produzca estenosis.
Résumé L'emploi d'un patch jéjunal bien vascularisé pour traiter les blessures de la voie biliaire fait l'objet de l'article. La méthode a été utilisée pour un cas de sténose de la voie biliaire principale et un cas de plaie n'intéressant pas la totalité de la circonférence du canal biliaire. Elle a pour avantages sa simplicité technique et le fait qu'elle assure une couverture muqueuse, sa persistante élasticité et le fait qu'elle présente un risque réduit de sténose.相似文献
27.
28.
Drug-resistance in Streptococcus pneumoniae isolates among Spanish middle aged and older adults with community-acquired pneumonia 总被引:1,自引:0,他引:1
Angel Vila-Corcoles Ferran Bejarano-Romero Elisabeth Salsench Olga Ochoa-Gondar Cinta de Diego Frederic Gomez-Bertomeu Xavier Raga-Luria Xavier Cliville-Guasch Victoria Arija 《BMC infectious diseases》2009,9(1):36
Background
Pneumococcal diseases remain a major cause of morbidity and mortality worldwide. Updated data on drug-resistance from different populations may be important to recognize changes in disease patterns. This study assessed current levels of penicilin resistance among Streptococcus Pneumoniae causing pneumonia in Spanish middle age and older adults. 相似文献29.
Age determines memory for face identity and expression 总被引:1,自引:1,他引:0
Egemen SAVASKAN Sandra Elisabeth MÜLLER reas BÖHRINGER Christine PHILIPPSEN Franz MÜLLER-SPAHN Hartmut SCHÄCHINGER 《Psychogeriatrics》2007,7(2):49-57
Background: The recognition of facial expressions is an important component of emotion processing which contributes to interactional behavior. One of the factors highly associated with potential decline of ability in behavioral tasks is age. Methods: We have investigated age‐related changes in facial identity and expression memory of healthy subjects in three age groups: young adults (20–40 years), elderly adults (60–80 years) and, for the first time in the literature, very old adults (over 80 years of age). Using a picture test, photographs of faces with happy or angry expressions were presented to study participants during the encoding task, and the memory for identity and emotional facial expression was investigated in a subsequent recognition task showing emotionally neutral faces. Half of the faces presented in the recognition task were initially shown in the encoding task. Results: Age interacted with the memory process: the ability to recognize both facial identity and emotional expression declined with advanced age. Happy facial expressions were better recognized in all age groups. Although there was a continuous overall decrease in recognition of both happy and angry expressions with advanced age, the effect favoring happy facial expressions was stable also in very old adults. Other factors such as gender or educational level did not affect the memory process for facial expressions. Conclusions: Our findings suggest that age is a significant determinant of memory for facial identity and emotional expression, and that, similar to younger adults, the recognition process of the elderly favors happy emotional facial expressions. 相似文献
30.
Functional dyspepsia (FD) is a highly prevalent gastrointestinal disorder and has a complex pathophysiology. Impaired fundic relaxation in response to a meal is present in 40% of patients with FD. This review focuses on impaired gastric accommodation of the stomach as a pathophysiological mechanism and the possible therapeutic targets that can be derived from the current knowledge of the neuroregulation of the accommodation reflex. First the different means of gastric accommodation assessment are described and the relationship between symptoms and impaired gastric accommodation. The different therapeutic options are subsequently discussed in view of their molecular target, based on the different receptor subtypes involved in the accommodation reflex. Although impaired gastric accommodation is highly prevalent in dyspeptic patients and basic knowledge about the accommodation reflex enables to develop pathophysiologically targeted therapies, it is unlikely that therapies aimed at dysaccommodation of the stomach will lead to symptom relief in all dyspeptic patients. A major challenge is the development of methods that readily identify impaired accommodation in clinical practice. 相似文献