全文获取类型
收费全文 | 18260篇 |
免费 | 964篇 |
国内免费 | 366篇 |
专业分类
耳鼻咽喉 | 631篇 |
儿科学 | 733篇 |
妇产科学 | 525篇 |
基础医学 | 2515篇 |
口腔科学 | 782篇 |
临床医学 | 2161篇 |
内科学 | 1563篇 |
皮肤病学 | 103篇 |
神经病学 | 1778篇 |
特种医学 | 590篇 |
外国民族医学 | 2篇 |
外科学 | 2268篇 |
综合类 | 2452篇 |
预防医学 | 1460篇 |
眼科学 | 455篇 |
药学 | 963篇 |
10篇 | |
中国医学 | 281篇 |
肿瘤学 | 318篇 |
出版年
2024年 | 27篇 |
2023年 | 199篇 |
2022年 | 449篇 |
2021年 | 587篇 |
2020年 | 535篇 |
2019年 | 438篇 |
2018年 | 426篇 |
2017年 | 480篇 |
2016年 | 536篇 |
2015年 | 594篇 |
2014年 | 1123篇 |
2013年 | 1225篇 |
2012年 | 1101篇 |
2011年 | 1271篇 |
2010年 | 1021篇 |
2009年 | 967篇 |
2008年 | 925篇 |
2007年 | 899篇 |
2006年 | 912篇 |
2005年 | 881篇 |
2004年 | 648篇 |
2003年 | 545篇 |
2002年 | 409篇 |
2001年 | 343篇 |
2000年 | 322篇 |
1999年 | 268篇 |
1998年 | 274篇 |
1997年 | 219篇 |
1996年 | 214篇 |
1995年 | 206篇 |
1994年 | 185篇 |
1993年 | 142篇 |
1992年 | 138篇 |
1991年 | 124篇 |
1990年 | 112篇 |
1989年 | 114篇 |
1988年 | 99篇 |
1987年 | 83篇 |
1986年 | 69篇 |
1985年 | 89篇 |
1984年 | 68篇 |
1983年 | 47篇 |
1982年 | 52篇 |
1981年 | 34篇 |
1980年 | 41篇 |
1979年 | 37篇 |
1978年 | 26篇 |
1977年 | 19篇 |
1976年 | 21篇 |
1973年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
E. Croce M. Golia M. Azzola R. Russo L. Crozzoli S. Olmi C. Pompa M. Borzio 《Surgical endoscopy》1996,10(11):1064-1068
Background: Thirty-three patients were candidates for laparoscopic choledochotomy. The indications for this operation are described.
Methods: The procedure was completed 32 times (97%). We had 29 successful common bile duct (CBD) clearances, three negative explorations,
and one failed clearance which needed to be converted to laparotomy. All the completed procedures ended with primary closure
of the main duct. Median duration of surgery was 180 min (range 100–300), including three associated laparoscopic procedures.
Results: There were three postoperative complications (9.4%), none major. Average postoperative hospital stay was 7.1 days (range
4–14). In May–June 1995 we controlled 31 out of the 32 consecutive patients (one patient was lost to follow-up) who had a
successful laparoscopic choledochotomy from October 1991 to December 1994. Median follow-up was 22 months (range 5–44). Besides
clinical control, 23 patients also had ultrasound (US) controls and 24 had blood tests. Eleven had intravenous cholangiotomography.
Two patients died 11 and 22 months after the operation for unrelated causes and without biliary symptoms. Two patients had
umbilical hernias. One had a small residual asymptomatic stone, which was removed endoscopically. None had signs of postoperative
CBD stricture. At US, CBD was ≤7 mm in 15 patients, 8–10 mm in four patients, and 10–12 mm in three patients. The last group
had preoperative CBD dilation, too. We could compare preoperative and postoperative CBD diameters in 22 patients: 11 had no
change; in nine it decreased; and two had a slight increase (8–10 mm).
Conclusions: We conclude that laparoscopic choledochotomy with primary closure is a very good operation: It has a high success rate and
low morbidity. Mortality is nil so far. Medium-term results are very positive: We had no CBD stricture and only one case of
asymptomatic residual stone, which could have been avoided. Our results suggest that intraductal biliary drainage is useless,
and its specific complications are well known.
Received: 20 October 1995/Accepted: 28 February 1996 相似文献
22.
Hitoshi Taguchi Koh Yamada Hideo Matsumoto Akira Kato Toshihiro Imanishi Koh Shingu 《Journal of anesthesia》1997,11(3):173-178
Purpose Several case reports indicate critical respiratory complications in relation to the double-lumen endobronchial tube (DLT).
A prospective survey for the airway problems in using the DLT is presented.
Methods One hundred adult patients undergoing thoracotomy for lung cancer were investigated. Tube malposition and airway obstruction
were searched using a fiber-optic scope. The endobronchial cuff was positioned just below the trachcal carina while the trachea
was intubated with a DLT (Rüsch). The distances of displacement, from the tracheal carina to the bronchial cuff, were measured
during anesthesia using an epidural catheter, which had marks every 5 mm. The distances for correcting the tube position were
measured at both the bronchial cuff and the level of the teethPaO2,PaCO2 andSPO2 were also measured.
Results Malposition (displacement over 5 mm from the correct position) was found in 42 patients, and 40 of them were in a withdrawal
direction, occurring at the postural change and during one-lung ventilation, especially during manipulation of the lung hilum.
Correcting distances at the level of the teeth were 15.3–3-times longer than those at the bronchial cuff. Airway deformities
and gradual withdrawal of the bronchial cuff were found in association with surgical manipulation. Obstruction occurred at
the tips of the tracheal tube in four patients and the bronchial tube in six patients, and at the tip of both in two patients.
Hypoxemia (PaO2<60 mmHg) occurred in four patients and hypercapnea (PaCO2>60 mm Hg) in two patients.
Conclusion Most of the DLT obstructions were associated with withdrawal malposition. Great attention to DLT displacement and airway deformity
is advised. 相似文献
23.
As part of a detailed study of limb defects and associated patterns of congenital malformations, cases with lower limb deficiencies were analysed separately. We identified a total of 130 cases with deficiencies of the lower limbs without defects of the upper limbs. This gives an incidence of 1.07/10,000 livebirths, or 1/9,337 for this group of limb defects. Most common were femur deficiencies and deficiencies of the foot. A preponderance of males was found in the group of transverse defects of the leg (fibula/tibia deficiencies) and central axis deficiencies, while females had significantly more often longitudinal tibia defects and preaxial ray defects. © 1993 Wiley-Liss, Inc. 相似文献
24.
Central nervous system (CNS) progenitor cells transiently proliferate in the embryonic neural tube and give rise to neurons and glial cells. A characteristic feature of the CNS progenitor cells is expression of the intermediate filament nestin and it was previously shown that the rat nestin second intron functions as an enhancer, directing gene expression to CNS progenitor cells. In this report we characterize the nestin enhancer in further detail. Cloning and sequence analysis of the rat and human nestin second introns revealed local domains of high sequence similarity in the 3' portion of the introns. Transgenic mice were generated with the most conserved 714 bp in the 3' portion of the intron, or with the complete, 1852 bp, human second intron, coupled to the reporter gene lacZ. The two constructs gave a very similar nestin-like expression pattern, indicating that the important control elements reside in the 714 bp element. Expression was observed starting in embryonic day (E)7.5 neural plate, and at E10.5 CNS progenitor cells throughout the neural tube expressed lacZ. At E12.5, lacZ expression was more restricted and confined to proliferating regions in the neural tube. An interesting difference, compared to the rat nestin second intron, was that the human intron at E10.5 mediated lacZ expression also in early migrating neural crest cells, which is a site of endogenous nestin expression. In conclusion, these data show that a relatively short, evolutionarily conserved region is sufficient to control gene expression in CNS progenitor cells, but that the same region differs between rodents and primates in its capacity to control expression in neural crest cells. 相似文献
25.
NAVIN C. NANDA M.D. SAYED MOHAMMED ABD-EL RAHMAN M.D. GAJENDRA KHATRI M.D. GOPAL AGRAWAL M.D. ADEL A. EL-SAYED M.D. HASSAN A. SHEHATA HASSANIAN M.D. MOHAMMAD KAMRAN M.D. JAMES KIRKLIN M.D. DAVID C. McGIFFIN M.D. WILLIAM L. HOLMAN M.D. ALBERT D. PACIFICO M.D. 《Echocardiography (Mount Kisco, N.Y.)》1995,12(6):619-628
In the present study, we compared three-dimensionally (3-D) reconstructed images with multiplane two-dimensional (2-D) transesophageal echocardiographic (TEE) images in 17 patients with various cardiac masses and defects. To overcome the problem of making measurements from 3-D reconstructed images, we carefully "dissected" the 3-D dataset using paraplane and anyplane 2-D sections, which were then used to obtain the maximum sizes of the cardiac masses and defects. Of the 15 vegetations and 9 abscesses detected by 3-D TEE in 7 patients, only 8 (53%) vegetations and 4 (44%) abscesses were detected by multiplane 2-D TEE (P < 0.02). Also, the exact anatomical location, shape, geometry, and extent of various cardiac masses and defects were more clearly delineated by 3-D than 2-D TEE. The maximum dimensions of cardiac masses and defects were larger by 3-D than by 2-D TEE in 17 (89%) of the 19 lesions available for comparison (P < 0.002). In addition, 3-D TEE correlated more closely than 2-D TEE when compared to surgical measurements in three patients in whom they were available. Thus, it would appear that in several instances, the exact size of the cardiac lesion could only be assessed by analysis of the 3-D volumetric dataset. Out preliminary study has demonstrated the superiority of transesophageal 3-D reconstruction over multiplane 2-D TEE in both qualitative and quantitative assessment of various cardiac mass lesions and pathological defects. 相似文献
26.
The best anastomotic agent to join nerve ends is controversial. This paper describes a controlled trial between a collagen tube wrap and a tissue glue to anastomose the rat facial nerve. There was no difference in the results using photographic, histological and electrophysiological techniques. 相似文献
27.
28.
手部创伤性骨关节缺损的处理 总被引:4,自引:0,他引:4
治疗手部骨关节缺损常采用植骨内固定、关节融合、关节成形及关节置换等方法.为总结经验,对1989年以来101例手部创伤性骨与关节缺损进行分析。单纯掌、指骨缺损39例,行直接短缩对位,克氏针内固定6例,1例发主骨不连;对33例缺损较大者用自体骨块植入克氏针交叉内固定,部分病例同时植人RBX或异体骨粒,10例发生延迟愈合,余全部正常愈合。骨与关节部分或完全缺损62例,采用关节成形术46例,其中以肋软骨移植效果最好,骨膜移植次之,筋膜衬垫或硅胶膜植入法较差;行关节融合术11例.均达顺利融合;采用自体关节置换5例,均成活,术后关节活动度均>70°。我们认为:自体骨块植入克氏针交叉内固定,必要时植入RBX骨粒.是治疗手部创伤性骨缺损的有效方法。关节缺损应按关节的重要性,分别采用关节融合术、关节成形术或关节置换术。 相似文献
29.
M. M. Ali S. Jayabalan M. Machnicki G. S. Sohal 《International journal of developmental neuroscience》2003,21(4):199-208
Virtually all cell types in the inner ear develop from the cells of the otic vesicle. The otic vesicle is formed by the invagination of non-neural ectodermal cells known as the otic placode. We investigated whether a recently described cell population, originating from the ventral part of the hindbrain neural tube known as the ventrally emigrating neural tube (VENT) cells, also contributes cells to the otic vesicle. The ventral hindbrain neural tube cells were labeled with the fluorescent vital dye DiI or replication-deficient retroviruses containing the LacZ gene in chick embryos on embryonic day 2, after the emigration of neural crest from this region. One day later, the labeled cells were detected only in the hindbrain neural tube. Shortly thereafter, the labeled cells began to appear in the eighth (vestibulocochlear) cranial nerve and otic vesicle. From embryonic day 3.5-5, the labeled cells were detected in the major derivatives of the otic vesicle, i.e. the endolymphatic duct, semicircular canals, utricle, saccule, cochlea, and vestibulocochlear ganglion. That the emigrated cells originated from the ventral part of the hindbrain neural tube was confirmed by focal application of DiI impregnated filter paper and with quail chimeras. It is concluded that, in addition to the otic placode cells, the otic vesicle also contains the ventrally emigrating neural tube cells, and that both cell populations contribute to the structures and cell types in the inner ear. It is well known that inductive signals from the hindbrain are required for the morphogenesis of the inner ear. The migration of the hindbrain neural tube cells into the otic vesicle raises the possibility that the inductive effect of the hindbrain might be mediated, at least in part, by the ventrally emigrating neural tube cells and that, therefore, a mechanism exists that involves cells rather than diffusible molecules only. 相似文献
30.
室间隔缺损的介入封堵治疗 总被引:2,自引:0,他引:2
对介入封堵治疗室间隔缺损的应用情况以及适应症、并发症等作一综述. 相似文献