全文获取类型
收费全文 | 5356篇 |
免费 | 269篇 |
国内免费 | 109篇 |
专业分类
耳鼻咽喉 | 75篇 |
儿科学 | 55篇 |
妇产科学 | 37篇 |
基础医学 | 711篇 |
口腔科学 | 462篇 |
临床医学 | 426篇 |
内科学 | 195篇 |
皮肤病学 | 51篇 |
神经病学 | 68篇 |
特种医学 | 535篇 |
外科学 | 1072篇 |
综合类 | 592篇 |
预防医学 | 187篇 |
眼科学 | 46篇 |
药学 | 477篇 |
1篇 | |
中国医学 | 295篇 |
肿瘤学 | 449篇 |
出版年
2024年 | 14篇 |
2023年 | 79篇 |
2022年 | 153篇 |
2021年 | 189篇 |
2020年 | 163篇 |
2019年 | 137篇 |
2018年 | 182篇 |
2017年 | 160篇 |
2016年 | 199篇 |
2015年 | 216篇 |
2014年 | 326篇 |
2013年 | 339篇 |
2012年 | 296篇 |
2011年 | 335篇 |
2010年 | 265篇 |
2009年 | 247篇 |
2008年 | 261篇 |
2007年 | 261篇 |
2006年 | 212篇 |
2005年 | 227篇 |
2004年 | 178篇 |
2003年 | 154篇 |
2002年 | 127篇 |
2001年 | 116篇 |
2000年 | 92篇 |
1999年 | 103篇 |
1998年 | 66篇 |
1997年 | 64篇 |
1996年 | 63篇 |
1995年 | 62篇 |
1994年 | 51篇 |
1993年 | 41篇 |
1992年 | 40篇 |
1991年 | 32篇 |
1990年 | 31篇 |
1989年 | 22篇 |
1988年 | 29篇 |
1987年 | 19篇 |
1986年 | 22篇 |
1985年 | 23篇 |
1984年 | 25篇 |
1983年 | 10篇 |
1982年 | 22篇 |
1981年 | 18篇 |
1980年 | 11篇 |
1979年 | 17篇 |
1978年 | 10篇 |
1977年 | 3篇 |
1976年 | 11篇 |
1975年 | 4篇 |
排序方式: 共有5734条查询结果,搜索用时 15 毫秒
11.
目的 通过临床与实验研究选择合适的皮片游离移植手术包扎材料.方法 实验分别以软质聚氨酯泡沫塑料、层叠干纱布、松散干沙团和干棉花团为测试包扎材料.分别在测试包扎材料上加压,记录血浆袋所受到的压力和包扎材料厚度压缩比例的变化;临床常规方法片皮移植,以软质聚氨酯泡沫塑料块加压包扎皮片.结果 软质聚氨酯泡沫塑料当外加压力使其压缩至原厚度的90%~34%时,可使皮片受到25 cmH2O~54.4 cmH2O的压力;此压力范围足以使皮片与创面密切接触,保证皮片成活,又避免过大的压力影响皮片血供重建.以软质聚氨酯泡沫塑料为包扎材料植皮,皮片成活率明显提高.结论 软质聚氨酯泡沫塑料是一种良好的植皮包装材料. 相似文献
12.
Dr. med. Dr. med. dent. Christof Holberg Katja Schwenzer Ingrid Rudzki-Janson 《Journal of orofacial orthopedics》2005,66(2):110-121
Abstract
Background and Aim:
The prediction of soft tissue esthetics is important for achieving an optimal esthetic outcome in orthodontic treatment planning. Applicable procedures have so far been restricted to two-dimensional profile predictions that have not proven to be very reliable. The goal of this investigation was therefore to develop a novel finite element-based procedure that allows a three-dimensional, easily visualized, quantitative analysis and prediction of soft tissue behavior for the clinician. The procedure to be developed should be easy to handle and not entail any additional radiation exposure for the patient.
Material and Methods:
Using a three-dimensional scanner, the facial surfaces of 20 probands were digitalized and individual FEM models were generated.
Results:
After reduction of data redundancy via several conversion steps, a patient-specific simulation model was prepared consisting of 20,000 to 40,000 individual elements to which specific physical properties could be assigned. The average time required for generating a virtual model was 50 minutes. Problems occurring during model generation were rare (mainly shadowing phenomena and movement artifacts).
Conclusion:
The procedure outlined herein makes the reliable generation of patient-specific simulation models possible for facial soft tissue prediction in orthodontics. 相似文献
13.
面颊部扩张皮瓣的设计和转移 总被引:7,自引:0,他引:7
目的探讨利用扩张皮瓣修复面颊不同部位皮肤缺损的扩张皮瓣设计。方法269例面颊部血管瘤、瘢痕、色素痣患者,依不同的皮肤缺损位置,在邻近部位放置大小适度的1~3个50~400ml容积的扩张器,扩张充分后采用推进皮瓣法、旋转推进皮瓣法和易位皮瓣法修复。结果269例中共形成305个扩张皮瓣,利用推进皮瓣121个,旋转推进皮瓣145个,易位皮瓣39个;共出现并发症52例,分别为扩张皮瓣远端血运障碍、血肿形成、感染、注水壶渗漏、扩张器外露、睑外翻和包囊挛缩,这些并发症基本未影响最终的手术效果,术后面颊部形态正常。结论我们提出的扩张皮瓣的设计和转移原则,对于面颊部的皮肤缺损组织扩张术治疗有非常重要的参考价值。 相似文献
14.
Abstract
Fifty moderate to severe hallux valgus deformities were corrected with a distal soft tissue realignment and proximal crescentic
metatarsal osteotomy. With an average follow-up of 5.6 years, 40 feet (80%) were pain free and 42 (84%) caused no functional
limitation. The average hallux valgus angle improved from 38.2° preoperatively to 12.4° at follow-up. The average intermetatarsal
angle improved from 15.4° to 6.8°. The arch of motion of the first metatarsophalangeal joint was 75° preoperatively and 62°
at follow-up. According to the AOFAS scoring system, 29 results (58%) were excellent, 14 (28%) good, 2 (4%) fair and 5 (10%)
poor. The 5 poor results were attributed to recurrence of hallux valgus (2 cases), stiffness (1), hallux varus (1) and malunion
of the osteotomy in dorsiflexion (1). The incidences of hallux varus and malunion in dorsiflexion were 8% and 14%, respectively.
This technique is valuable in correction of moderate to severe hallux valgus deformities. 相似文献
15.
梗阻性脑积水侧脑室及室周脑组织生物力学响应的有限元分析 总被引:1,自引:0,他引:1
目的运用有限元方法对梗阻性脑积水进行计算机模拟,研究分析侧脑室及室周脑组织的生物力学响应及其所产生的病理生理影响。方法依据正常国人颅脑MRI轴位T2加权图像获取解剖信息,在有限元软件ANSYS中生成包含侧脑室前、后角和体部的半侧脑层面的二维有限元模型。模拟脑组织为固、液两相物质组成的线性多孔弹性材料,设定生物力学特性参数及边界条件和初始条件,施加载荷,运用有限元软件ABAQUS进行计算求解,以云图形式输出结果。结果有限元模型动态模拟了梗阻性脑积水侧脑室各部的扩张过程,直观显示出各个时间步室周脑组织内的应力类型及分布、各部的应变和位移。结论膨胀性应力集中引起角部脑水肿;梗阻性脑积水早期侧脑室角部形态变化最明显;体部附近脑组织结构容易受压移位。这些生物力学响应是室内压增高的结果,也与侧脑室的解剖形态密切相关。 相似文献
16.
Solitary fibrous tumors (SFT) have recently been established to be of mesenchymal origin. Although there are numerous reports
of SFTs arising from the pleura, reports of the tumor arising from extrapleural sites are comparatively rare [Fletcher CDM,
Unni K, Mertens F (eds) World Health Organization classification of tumors, pathology & genetics, tumors of soft tissue and bone. IARC Press, Lyon, pp 86–901, 2002]. We report a case of SFT arising in the inguinal region. 相似文献
17.
自1999年1月-2005年3月,应用胫前肌瓣修复胫骨骨髓炎合并软组织缺损13例,同时辅以中药治疗,获得较满意的效果,现报告如下。1临床资料本组13例,男9例,女4例;年龄1867岁,平均32岁。致伤原因:车祸伤6例,挤压伤4例,烧伤1例,坠落伤2例。胫骨上1/3段1例,中1/3段2例,下1/3段5例,中下2/3段5例。病程12d30个月,外露骨有干燥、硬化、发白、变黑,周围有肉芽、瘢痕组织、脓性分泌物等。外露骨纵形长0·68·0cm,皮肤缺损面积最大为4cm×10cm。2治疗方法2·1手术方法在硬膜外麻醉下,股部上止血带,术区常规消毒。首先切除溃疡及外露胫骨周围瘢痕,清除髓腔内分泌物及 相似文献
18.
颌面部爆炸伤软组织缺损早期修复的实验研究 总被引:16,自引:4,他引:12
将犬随机分为A(即时)组、B(72h)组,采用KTY-04型雷管置于犬面颊部引爆致伤,造成软组织洞穿性缺损。A组伤后即刻清创、隐动脉皮瓣立即移植修复皮肤缺损;B组伤后即刻清创,72h后二次清创,同时切取隐动脉皮瓣,吻合血管修复皮肤缺损,颊粘膜缺损两组均行局部拉拢缝合。术后观察1~6个月,A组5例均失败;B组15例,成功12例,游离皮瓣成活率为80%。实验结果表明口腔颌面部爆炸伤软组织缺损经早期清创,72h后扩创,用吻合血管游离皮瓣修复是可行的。 相似文献
19.
A. P. Dei Tos Paola Dal Cin 《Virchows Archiv : an international journal of pathology》1997,431(2):83-94
Soft tissue tumours represent a heterogeneous group of mesenchymal lesions, and their classification is the subject of continuous
debate. Chromosome analysis, molecular cytogenetics and molecular assays may become increasingly useful in diagnosis, and
this review summarises advances in the cytogenetic characterisation and classification of soft tissue tumours. Among the group
of fibrous lesions, superficial fibromatosis exhibits trisomy 8. This genomic change is also observed in desmoid fibromatosis
in association with trisomy 20. Trisomy 11 is the most frequently observed chromosomal aberration in congenital fibrosarcoma.
Dermatofibrosarcoma protuberans and giant cell fibroblastoma share a translocation t(17;22), which supports the concept of
the existence of a common differentiation pathway. Adipose tissue tumours is the group in which integration of genetics and
pathology has been most fruitful. Ordinary lipomas cytogenetically show an abnormal karyotype in about half the cases. Genomic
changes of the 11q13 region are observed in hibernoma. Lipoblastoma exhibits a specific 8q rearrangement in 8q11-q13. Loss
of material from the region 16q13-qter and 13q deletions are observed in spindle cell/pleomorphic lipomas. The well-differentiated
liposarcoma/atypical lipoma group is characterised karyotypically by the presence of one extra ring and/or extra giant chromosome
marker. Myxoid and round cell liposarcoma share the same characteristic chromosome change: t(12;16)(q13;p11) in most cases.
In the group of smooth muscle lesions most data are derived from uterine leiomyomas, which can be subclassified cytogenetically
into seven different types. Half of all leiomyomas are chromosomally normal; the other half have one of six possible consistent
chromosome changes. Alveolar rhabdomyosarcoma is characterised cytogenetically by two variant translocations t(2;13)(q35;q14)
and t(1;13)(p36;q14). Among tenosynovial tumours, the localised type of giant cell tumour of tendon sheath exhibits two different
karyotypic changes. One involves 1p11 in a translocation with chromosome 2 or with another chromosome. A second type involves
16q24. Synovial sarcoma is characterised cytogenetically by a translocation occurring between chromosome 18 and presumably
two adjacent loci on the X chromosome. In neural tumours, abnormalities of chromosome 22 have been reported in benign schwannomas
and perineuriomas. Malignant peripheral nerve sheath tumours exist in two main forms: sporadic and associated with the NF-1
syndrome. Karyotypes are very complex, but chromosomes 17q and 22q are very often involved. Clear cell sarcoma is characterised
cytogenetically and molecularly by a translocation t(12;22)(q13;q12). The Ewing’s sarcoma/peripheral neuroectodermal tumour
category shows a central karyotypic anomaly represented by the translocation t(11;22). The two variants t(21;22) and t(7;22)
are found in some cases. Among cartilaginous lesion, the most frequently described anomaly is the t(9;22)(q22;q12) in extraskeletal
myxoid chondrosarcoma. Intra-abdominal desmoplastic small round cell tumour is characterised by a t(11;22)(p13;q12).
Received: 5 February 1997 / Accepted: 24 February 1997 相似文献
20.
We describe the enhancement patterns of myoepithelioma in two patients with a soft palate mass. In the first case, helical CT revealed a faintly enhancing mass. Histologically, the tumor was composed of plasmacytoid cells in a background of rich myxoid stroma. Immunostaining for CD34 showed scanty blood vessels. In the second case, helical CT revealed an intensely enhancing mass. Histologically, the mass was a cellular tumor with fibrous stroma. Immunostaining for CD34 also showed frequent blood vessels. 相似文献