全文获取类型
收费全文 | 3107篇 |
免费 | 168篇 |
国内免费 | 86篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 84篇 |
妇产科学 | 14篇 |
基础医学 | 437篇 |
口腔科学 | 66篇 |
临床医学 | 274篇 |
内科学 | 754篇 |
皮肤病学 | 41篇 |
神经病学 | 290篇 |
特种医学 | 364篇 |
外科学 | 427篇 |
综合类 | 37篇 |
预防医学 | 156篇 |
眼科学 | 51篇 |
药学 | 172篇 |
肿瘤学 | 173篇 |
出版年
2023年 | 17篇 |
2021年 | 42篇 |
2020年 | 46篇 |
2019年 | 38篇 |
2018年 | 53篇 |
2017年 | 31篇 |
2016年 | 43篇 |
2015年 | 51篇 |
2014年 | 65篇 |
2013年 | 95篇 |
2012年 | 138篇 |
2011年 | 130篇 |
2010年 | 97篇 |
2009年 | 114篇 |
2008年 | 139篇 |
2007年 | 161篇 |
2006年 | 96篇 |
2005年 | 138篇 |
2004年 | 111篇 |
2003年 | 142篇 |
2002年 | 117篇 |
2001年 | 81篇 |
2000年 | 53篇 |
1999年 | 54篇 |
1998年 | 85篇 |
1997年 | 102篇 |
1996年 | 83篇 |
1995年 | 85篇 |
1994年 | 47篇 |
1993年 | 52篇 |
1992年 | 36篇 |
1991年 | 52篇 |
1990年 | 35篇 |
1989年 | 59篇 |
1988年 | 54篇 |
1987年 | 38篇 |
1986年 | 46篇 |
1985年 | 64篇 |
1984年 | 33篇 |
1983年 | 30篇 |
1982年 | 49篇 |
1981年 | 42篇 |
1980年 | 42篇 |
1979年 | 22篇 |
1978年 | 14篇 |
1977年 | 30篇 |
1976年 | 29篇 |
1975年 | 19篇 |
1974年 | 19篇 |
1970年 | 15篇 |
排序方式: 共有3361条查询结果,搜索用时 15 毫秒
1.
Stephen H. Olsen Linglei Ma Bertram Schnitzer Douglas R. Fullen 《Journal of cutaneous pathology》2009,36(3):302-307
Background: Clusterin is a ubiquitous 80 kDa heterodimeric glycoprotein previously shown to be expressed on tumor cells of systemic and, to a lesser extent, primary cutaneous anaplastic large cell lymphoma (PC-ALCL). Lymphomatoid papulosis (LyP), an important differential diagnosis of ALCL, has been studied for clusterin expression in only a small number of cases. The aim of this study was to compare clusterin immunostaining patterns in LyP and other cutaneous histologic simulants with those of PC-ALCL.
Methods: Formalin-fixed, paraffin-embedded sections of PC-ALCL (6), LyP (20), mycosis fungoides with large cell transformation (MF-LCT, 12), pityriasis lichenoides et varioliformis acuta (PLEVA, 12), arthropod bite reaction (ABR, 12) and lymphomatoid reactions (LR, 9) were immunostained for clusterin and evaluated for staining pattern and distribution. All diagnoses were made with clinicopathologic correlation.
Results: Characteristic dot-like Golgi staining was identified in 10/20 LyP (50%), 4/6 PC-ALCL (67%) and 9/12 MF-LCT (75%). Two of 12 PLEVA (17%), 1 of 12 ABR (8%) and 2 of 8 LR (25%) had lymphocytes (< 25%) with diffuse cytoplasmic staining. Dermal dendritic cells stained strongly for clusterin. High background staining occurred in some cases.
Conclusion: Clusterin immunostaining does not reliably distinguish between LyP, PC-ALCL or MF-LCT, but could distinguish LyP from its reactive histologic simulants. 相似文献
Methods: Formalin-fixed, paraffin-embedded sections of PC-ALCL (6), LyP (20), mycosis fungoides with large cell transformation (MF-LCT, 12), pityriasis lichenoides et varioliformis acuta (PLEVA, 12), arthropod bite reaction (ABR, 12) and lymphomatoid reactions (LR, 9) were immunostained for clusterin and evaluated for staining pattern and distribution. All diagnoses were made with clinicopathologic correlation.
Results: Characteristic dot-like Golgi staining was identified in 10/20 LyP (50%), 4/6 PC-ALCL (67%) and 9/12 MF-LCT (75%). Two of 12 PLEVA (17%), 1 of 12 ABR (8%) and 2 of 8 LR (25%) had lymphocytes (< 25%) with diffuse cytoplasmic staining. Dermal dendritic cells stained strongly for clusterin. High background staining occurred in some cases.
Conclusion: Clusterin immunostaining does not reliably distinguish between LyP, PC-ALCL or MF-LCT, but could distinguish LyP from its reactive histologic simulants. 相似文献
2.
Coronary artery bypass grafts: visualization with MR imaging 总被引:1,自引:0,他引:1
3.
The course of schizophrenia: Some remarks on a yet unsolved problem of retrospective data collection
Wolfram an der Heiden Bertram Krumm 《European archives of psychiatry and clinical neuroscience》1991,240(4-5):303-306
Summary The retrospective assessment of symptoms and syndromes is a basic measure in research of the longitudinal course of schizophrenia. In spite of its importance there have been few studies evaluating the standard of quality of instruments for retrospective data collection. Combining retrospectively and cross-sectionally collected data on schizophrenic symptomatology in a cohort study over a period of 5 years revealed a significant underestimation of symptoms when assessed in retrospect. The need for studies on the validity of instruments for the retrospective assessment of symptoms is stressed. 相似文献
4.
5.
6.
D. Chemla P. Démolis M. Thyrault D. Annane Y. Lecarpentier and JF Giudicelli 《Fundamental & clinical pharmacology》1996,10(4):393-399
Summary— The influence of local resistance and cardiac performance on peripheral blood acceleration was investigated in 14 healthy male volunteers. Steady and pulsatile flow was studied in the brachial and in the common carotid arteries, ie, two territories that exhibit marked differences in resistive characteristics. Instantaneous blood velocity (V), mean blood velocity (Vm ) and artery diameter (D) were evaluated at rest by an ultrasonic range-gated pulsed Doppler flowmeter using a double transducer probe, thus allowing the calculation of mean blood flow (Q). Mean local resistance (R) was obtained by dividing the mean arterial pressure by Q. The peak value of the local acceleration of the blood was obtained by computer-assisted calculation of the first derivative of instantaneous blood velocity (Gmax = +dV/dtmax ). Peak aortic blood acceleration (GAo) was simultaneously measured from the suprasternal notch using a pulsed Doppler velocity meter. In the brachial and the common carotid arteries, Gmax was of a similar magnitude (551 ±30 and 555 ± 44 cm/s2 , respectively) despite major differences in the respective D, Vm , Q and R values. In neither artery was there a relationship between Gmax and either resting Q or R. At the brachial artery level, Gmax was positively related to GAo ( r = 0.79, P = 0.0008). At the common carotid artery level, there was a weak, although non significant relationship between Gmax and GAo ( P = 0.08). Our results indicate that the local acceleration of peripheral blood flow in the brachial artery is related rather to upstream central impulse than to downstream hemodynamics, and suggest some regional differences in the hemodynamic determinants of the local acceleration of peripheral blood flow. 相似文献
7.
8.
In a prospective, randomized, double-blind study, 49 patients underwent lumbar myelography using iotrol (24 patients) or metrizamide (25 patients). The diagnostic imaging adequacy of iotrol was comparable with that of metrizamide. After iotrol myelography, adverse reactions were fewer, less severe, and of shorter duration than were those following metrizamide myelography. Thirteen of 24 patients (54%) receiving iotrol reported some adverse reactions compared with 24 of 25 patients (96%) receiving metrizamide. Five moderate and one severe adverse reaction occurred in the group receiving iotrol. Fourteen moderate and eight severe adverse reactions occurred in the group receiving metrizamide. Thirty-eight patients underwent electroencephalography both before and after myelography (19 iotrol and 19 metrizamide). None of the EEGs obtained after iotrol myelography changed from baseline, while seven of the EEGs obtained after metrizamide myelography showed changes from baseline. Iotrol was judged superior to metrizamide as a contrast medium in this patient population. 相似文献
9.
10.
P. Bertram K. -H. Treutner G. Winkeltau H. -J. Booß G. Staatz Prof. Dr. V. Schumpelick 《Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie》1993,378(4):249-254
Zusammenfassung Die Pneumatosis cystoides intestinii (PCI), das Auftreten submuköser oder subseröser, gasgefüllter Zysten in der Wand des Gastrointestinaltrakts, tritt als seltene Erkrankung ohne eindeutige Geschlechtspräferenz vorwiegend in der 3. bis 5. Lebensdekade auf. Atiopathogenetisch werden unterschiedliche Faktoren diskutiert, am wahrscheinlichsten ist eine bakterielle Ursache (Clostridium perfringens) in Verbindung mit einer minimalen Unterbrechung der Mukosaintegrität. Eine pathognomonische Symptomatik gibt es nicht, das klinische Bild reicht von asymptomatischen Zufallsbefunden bis zur Hämatochezie. Die Diagnose wird durch den Nachweis der Gaseinschlüsse mittels Abdomenübersichtsaufnahme und Kolonkontrasteinlauf gestellt. Als Behandlungsmethoden für symptomatische Patienten stehen Sauerstofftherapie, Antibiotikagabe (Metronidazol) und in schweren Fällen die Resektion des betroffenen Darmabschnitts zur Verfügung.
Pneumatosis cystoides intestinalis (PCI), a condition involving submucosal or subserosal gas-containing cysts of the wall of the gastrointestinal tract, is a rare entity. It is mostly diagnosed between the third and fifth decades of life without a clear sexual predominance. Different aetiopathogenetic factors are under discussion, the most probable being a bacteriologic cause (Clostridium perfringens) in combination with minimal leaks in mucosal barrier. There are no pathognomonic symptoms; the clinical picture ranges from incidental findings to haematochezia. Diagnosis is based on plain abdominal film and X-ray following barium enema. Methods of treatment in symptomatic cases are oxygen and antibiotic (metronidazole) therapies and, in severe cases, resection of the diseased part of the intestine.相似文献