首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   15227篇
  免费   895篇
  国内免费   56篇
耳鼻咽喉   176篇
儿科学   389篇
妇产科学   293篇
基础医学   2016篇
口腔科学   364篇
临床医学   1396篇
内科学   3564篇
皮肤病学   201篇
神经病学   1402篇
特种医学   559篇
外国民族医学   1篇
外科学   2335篇
综合类   138篇
一般理论   4篇
预防医学   1091篇
眼科学   252篇
药学   899篇
中国医学   35篇
肿瘤学   1063篇
  2023年   124篇
  2022年   259篇
  2021年   526篇
  2020年   287篇
  2019年   423篇
  2018年   479篇
  2017年   338篇
  2016年   345篇
  2015年   393篇
  2014年   555篇
  2013年   743篇
  2012年   1168篇
  2011年   1105篇
  2010年   678篇
  2009年   511篇
  2008年   876篇
  2007年   887篇
  2006年   757篇
  2005年   783篇
  2004年   695篇
  2003年   609篇
  2002年   632篇
  2001年   240篇
  2000年   223篇
  1999年   225篇
  1998年   125篇
  1997年   107篇
  1996年   88篇
  1995年   92篇
  1994年   78篇
  1993年   60篇
  1992年   110篇
  1991年   79篇
  1990年   101篇
  1989年   99篇
  1988年   89篇
  1987年   82篇
  1986年   96篇
  1985年   79篇
  1984年   69篇
  1983年   83篇
  1982年   58篇
  1981年   45篇
  1980年   46篇
  1979年   53篇
  1977年   43篇
  1975年   46篇
  1974年   49篇
  1973年   51篇
  1972年   49篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
Many of the unsatisfactory results in cosmetic surgery are due not to the technique employed itself but to the virtual changes that our work has imposed in other areas. These changes are especially evident in the face, due to the small dimensions of its organs. The surgeon should do a thorough evaluation of the area to be treated prior to the surgery and make her/him notice not only the usual existing asymmetries, but also the modifications which probably will be noticed in the neighboring parts after surgery, to avoid later problems. The surgeon will discover then the many irregularities a patient may have, which have not been noticed by the patient before. These, if not detected in time, are weapons that may act as a boomerang against the surgeon later.  相似文献   
93.
94.
95.
Zusammenfassung Bei einem 47 jährigen Patienten entwickelten sich am rechten Bein mehrere rasch wachsende Tumoren von distal nach proximal. Histologisch und elektronenmikroskopisch zeigten die Tumorzellen morphologische Besonderheiten, die für ihre histiocytäre Provenienz sprechen. Auffallend war die große Anzahl polymorpher cytoplasmatischer Membranstrukturen und großer Vacuolen, die massenhaft kleine Vesikel enthielten. Diese Strukturen werden als transformierte multivesiculäre Körper gedeutet; ihre Entstehung vollzieht sich im Rahmen einer bizarr übersteigerten Membranaktivierung einer malignen Zellrasse. Bemerkenswert ist die rasche und völlige Remission durch Radiotherapie.
Multivesicular vacuolization in malignant histiocytoma of the skin
Summary A 47-year-old patient developed several rapidly growing tumours in his right leg. Histologic and electron microscopic examination revealed morphological characteristics suggesting the histiocytic origin of the tumour cells. An important finding was the striking number of pleomorphic membraneous inclusions and large vacuoles containing numerous small vesicles. These cytoplasmic inclusions are interpreted as transformed multivesicular bodies. Their formation may be an expression of an increased and bizarre membraneous activity of a malignant cell race. Radiotherapy resulted in a remarkably rapid and complete remission.


Auszugsweise vorgetragen beim 4th European Meeting on Electron Microscopy Applied on Cutaneous Pathology, Heidelberg, 6. und 7. Mai 1977: Multivesicular Vacuolization in Malignant Histiocytoma.  相似文献   
96.
Seizures and civilian head injuries   总被引:4,自引:3,他引:1  
Although several studies have reported on the risk of "early seizures" (seizures occurring within 7 days following a head injury), the reported proportions of patients experiencing these seizures vary from 1.4 to 15%. This wide divergence may be due to problems with methodology such as case selection and definitions of head injury and early seizures. In a series of 702 patients admitted with a head injury to Cook County Hospital (CCH), Chicago, Illinois, 29 (4.1%) had early seizures. This proportion is twice as high as one previously reported in a comparable series. This may reflect an actual difference between the two series or a case selection bias serving to elevate the proportion of patients with early seizures at CCH.  相似文献   
97.
Summary The chemoattractants, N-formyl-L-methio-nyl-L-leucyl-L-phenylalanine (fMet-Leu-Phe), complement C5a and platelet-activating factor (PAF), induce ß-glucuronidase release and aggregation and an increase in cytosolic Ca2+ [Ca2+]i in human neutrophils. We studied the roles of cAMP and cGMP in neutrophil avtivation, using their cell-permeant analogues, N6,2-O-dibutyryl adenosine 3:5-cyclic monophosphate (Bt2cAMP) and N2 ,2-O-dibutyryl guanosine 3:5-cyclic monophosphate (Bt2cGMP) and the NO-containing compounds, sodium nitroprusside (SNP), 3-morpholino-sydnonimine (SIN-1) and its prodrug, molsidomine (SIN-10). Bt2cAMP, Bt2cGMP, SIN-1 and SIN-10 but not SNP inhibited exocytosis induced by fMet-Leu-Phe. Superoxide dismutase potentiated the inhibitory effect of SIN-1. Bt2cGMP and SNP potentiated C5a-induced ß-glucuronidase release, Bt2cAMP, KCN, SIN-1 and SIN-10 being ineffective. KCN partially reversed the stimulatory effect of SNP, and in the presence of superoxide dismutase, SIN-1 potentiated C5a-induced exocytosis. PAF-induced ß-glucuronidase release was not affected by Bt2cAMP, Bt2cGMP, SNP and SIN-1. Bt2cGMP was more effective than Bt2cAMP to inhibit aggregation and the increase in [Ca2+]i induced by fet-Leu-Phe at submaximally effective concentrations. C5a-induced rises in [Ca2+]i were not affected by Bt2cAMP and Bt2cGMP. Bt2cAMP but not Bt2cGMP inhibited the effect of PAF at submaximally effective concentrations on [Ca2+]i. Our data suggest (I) that Bt2cGMP and Bt2cAMP differentially modulate neutrophil activation, that (II) NO-containing compounds partially mimick the effects of Bt2cGMP on exocytosis and that (III) cGMP plays an inhibitory role in fMet-Leu-Phe- and a stimulatory role in C5a-induced ß-glucuronidase release. Send offprint requests to R. Seifert at the above address  相似文献   
98.
The role of cavitation during shock wave exposure was poorly understood until now. Cavitational activity produces severe damage to nearby surfaces due to multiple high-speed liquid jets resulting from bubble collapse. These jet impacts can be made visible by microscopy. For investigating the presence of cavitational processes by shock waves outside and even inside of targets, we have performed the following experiments. Natural gallstones and artificial targets were examined microscopically with regard to the effects of shock pulses. Scanning electron and light microscopical investigations revealed regularly typical and uniform microjet impacts within the fissures and split lines. Since these experiments are the continuation of high-speed films of 10,000 frames/s of shock wave actions on targets, it is most likely that the shock wave produces at first split lines through the stone. Then liquid occupies these cracks. But the following shock waves create within these liquid-filled fissures cavitation and, therefore, cause the disintegration of the targets. It now becomes understandable why biliary lithotripsy is less effective than renal lithotripsy: bile fluid is a high-viscous liquid and, therefore, hinders the disintegration of stones more than low-viscous urine. Intervals between the application of shock waves in biliary lithotripsy, therefore, should improve the treatment results.  相似文献   
99.
G Seifert  I Langrock  K Donath 《HNO》1976,24(12):415-426
Pleomorphic adenomas of the salivary glands show, despite their pleomorphism, certain histological characteristics. These are based onthe differentiation of the epithelial cell and the amount and nature of the stroma. A systematic histological analysis of 310 pleomorphic adenomas of the parotid gland resulted in the following findings and classification. 1. The most frequent epithelial cell forms were salivary duct and myoepithelial cells (75-90%) seen as epidermoid cell groups (75%). Rarer forms of differentiation were striated duct cells (5%), keratinised squamous epithelium (2,5%), oncocytes (1%), basal cells (1%), and sebaceous gland cells or goblet cells (less than 1%). 2. A myxomatous stroma represented the prototype of stromal differentiation (80%). A chondroid stroma was found in 10% of cases examined and a mixed mucochondroid stroma in 3%. Further differentiation included hyaline stroma (25%) and fibrous stroma (15%) especially in the older tumour or after irradiation. Rarely was a fascicular (0,5%) or osseous (1%) stromal change found. 3. Four subgroups of pleomorphic adenoma can be classified from consideration of the epithelial and stromal changes. Subgroup 1 (30,5%) is the classical pleomorphic adenoma with a stroma content of 30-50%; subgroup 2 (55%) has a stroma content of 80%; subgroup 3 (9%) has a poor stroma content of 20-30% or less and an epitaelial differentiation similar to subgroup 1; and subgroup 4 has also a poor stroma content (6%) with a relatively monomorphic epithelial structure. 4. Recurrences (13,5%) were seen more in stroma-rich pleomorphic adenomas than in stroma-poor tumours. 5. On the basis of cytological differentiation, pleomorphic adenomas develop from indifferent tissue adjacent to salivary intercalated or striated ducts.  相似文献   
100.
Zusammenfassung Anhand der anamnestischen Daten von 50 Patienten mit chronischer posttraumatischer Osteomyelitis wird eine Punktebewertung zur Beurteilung des Schweregrades der Erkrankung entwickelt, die neben der Gesamtdauer der Erkrankung den prozentualen Anteil der stationären Behandlung sowie die Anzahl der chirurgischen Eingriffe berücksichtigt. Zur Objektivierung des klinischen Verlaufes wird eine zweite Skala (München-Murnau-Skala) vorgestellt, welche die äußeren Wundverhältnisse, die röntgenologischen Befunde sowie die Blutkörperchensenkungsgeschwindigkeit erfaßt. Anhand einer Autovaccinetherapie bei 18 Patienten wird die Objektivierung des Therapieerfolges mit Hilfe dieser Skala gezeigt.
Scoring system for evaluation of severity and progress of chronic posttraumatic osteomyelitis
Summary From the anamnestic data of 50 patients suffering from chronic posttraumatic osteomyelitis a severity scoring system was developed, based on the duration of the disease, the time of hospitalization and the number of surgical interventions. The clinical course of 18 patients, undergoing an auto-vaccination treatment, was registered by another scoring system (Munich-Murnau-Scale) regarding wound morphology, bone radiology and erythrocyte sedimentation rate.
  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号