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91.
92.
目的 探讨牙齿不同部位之间、易患龋牙与非易患龋牙之间牙釉质表面氟浓度有无差异。方法 收集上海、北京和深圳3个地区儿童的下颌乳中切牙45颗,并利用微样酸蚀法分析乳牙釉质表面氟元素的分布。结果 氟浓度从釉质表面到内部有由高到低的变化趋势,牙磨耗是牙齿丧失氟的重要元素,未发现釉质表层氟浓度与龋蚀指数(CSI)、龋补牙数(dft)有相关性(P>0.05)。结论 乳牙釉质表面氟浓度与患龋状况无明显相关性。 相似文献
93.
Percutaneous transcatheter occlusion of coronary artery fistulas using detachable balloons 总被引:1,自引:0,他引:1
Three pediatric patients underwent successful transcatheter coronary artery fistula occlusion using the Debrun system. This
latex balloon system offers several advantages over other occlusion systems. First, the balloon delivery and release is controlled.
Second, “test occlusions” can be performed that allow simultaneous balloon inflation, coronary cineangiography, and electrocardiographic
monitoring. Third, because the balloons are flow-directed, they are easily positioned in properly chosen locations. Finally,
the balloons can be constructed to suit the size of the fistula. In this study, two patients received only one balloon; in
the other patient two balloons were placed in the same fistula. All fistulas drained into either the right atrium or ventricle
and were successfully occluded. After a follow-up period of up to 3 years, no local or systemic reactions to the balloons
were recognized. We conclude that detachable balloon occlusion of coronary artery fistulas is a safe, effective alternative
to surgical ligation in selected pediatric patients. 相似文献
94.
Neuropathological findings in two siblings with familial erythrophagocytic lymphohistiocytosis (FEL) are reported. Case 1 showed the typical neuropathological findings of FEL with lymphohistiocytic infiltration of the leptomeninges and perivascular spaces. A characteristic erythrophagocytosis was detected in inguinal lymph nodes, lung and bone marrow. Case 2 revealed calcification and necrotic lesions in the brain. In the necrotic areas, parenchymal calcification, vascular medial calcification, and occlusion of many vessels due to subendothelial fibrosis were detected. The areas of necrosis correlated with the distribution of occluded vessels. These changes were most prominent in putamen, internal capsule, thalamus and dentate nucleus. Hypercytokinemia is suspected to be the underlying mechanism for the clinical and laboratory findings in patients with FEL, although the relationship to the vascular pathology is unclear. 相似文献
95.
功能性矫治器是正畸临床中常用的一种矫治器,作者从口腔正畸学理论基础出发,探讨了功能性矫治器在正畸矫治作用中存在的伦理道德问题,主要有(1)不能正确的诊断、制定周密的矫治计划。(2)操作不规范、不细致、缺乏敬业精神。(3)态度简单,粗曝,缺乏与患者良好的交流。并提出解决方法(1)刻苦学习专业知识,不断提高诊疗水平及个人修养。(2)建立高度的道德责任感,以严谨的作风,规范的操作为病人服务。(3)尊重、善待青少年,建立良好的医患关系。 相似文献
96.
Gérard Brunel Edmond Benqué Frédéric Elharar Catherine Sansac Jean François Duffort Pierre Barthet Eric Baysse Neal Miller 《Clinical oral implants research》1998,9(5):303-312
The aim of the present study was to evaluate the combined application of different bioabsorbable materials for healing of residual peri‐implant defects after placement of non‐submerged implants into fresh extraction sockets. Second and third mandibular premolars were extracted from 10 Beagle dogs, the coronal part of the distal sockets were surgically enlarged and this was followed by immediate placement of specially designed hollow‐screw non‐submerged dental implants. For each animal, the coronal peri‐implant defects were further treated with one of the 4 following procedures: 1) no treatment, control site: 2) grafting with porous hydroxyapatite (HA); 3) collagen membrane tightly secured around the implant and over the defect and 4) grafting with HA covered with a collagen membrane. After 16 weeks of healing, specimens were removed from the mandibule and prepared for a histomorphometric evaluation. The bone-to-implant contact length (BIC) was measured and compared amongst the different treatment modalities. In the defect area, the irregular bone regeneration was similar between all the treatment procedures ( P >0.10). In the sites covered with a collagen membrane alone, the total BIC (47%) was greater than in control sites (28.7%. P <0.05) or sites grafted with HA (22.2%, P <0.02). Total BIC in sites treated with the HA‐membrane combination (43%) was only significantly different from sites treated with HA ( P <0.10). It is concluded that the use of bioabsorbable materials results in a limited increase of osseointegration when used in conjunction with immediate placement of non-submerged implants, although the principle of the one stage surgical approach can be maintained. 相似文献
97.
A 5-year retrospective analysis of employer-provided dental care for Finnish male industrial workers
Jari Ahlberg Risto Tuominen Heikki Murtomaa 《Community dentistry and oral epidemiology》1997,25(6):419-422
Abstract The treatment-mix, treatment time, and dental status of 268 male industrial workers entitled to employer-provided dental care were studied. The data were collected from treatment records of the covered workers over the 5-year period 1989-93. Treatment time was based on clinical treatment time recorded per patient visit, and the treatment procedure codes were reclassified into a treatment-mix according to American Dental Association categories, with a modification combining endodontics and restorative treatment. The mean number of check-ups followed by prescribed treatment (treatment courses) during the 5 years was 3.7 among those who had entered the in-house dental care program prior to the monitored period (old attenders). Their treatment time was stable, 57–63 min per year, while the first-year mean treatment time (170 min) of those who had entered the program during the study period (new attenders) was significantly higher (P<0.01) than the 5-year mean of the old attenders (61 min). Over the first 2 years, the treatment-mix of the new attenders showed a rise in diagnostic and preventive procedures from one-third to about one-half of all procedures, as it was for the old attenders. The new attenders' mean number of carious teeth (2.7), registered at the initial check-up visit, paralleled the mean recently demonstrated in the similar non-covered population. It was significantly higher than the 5-year mean of the old attenders (0.5) (P<0.001), but declined to the same level after the first year of treatment. It was concluded that the studied program seemed to contribute to a stabilization of treatment-mix, and to the establishment of a shorter annual treatment time within the first 2 years of treatment. 相似文献
98.
目的 研究电化学人工龋的电化学腐蚀机制。方法 采用循环伏安法研究牙片电极在K2SO4溶液中的氧化还原反应;以失重法并结合SPSS统计软件统计分析,评价牙片在KCl和K2SO4介质中恒电位腐蚀情况,并现场监测电解液氢离子浓度的变化情况。结果 在0.0-2.5V电位范围内,牙片电极与石墨电极具有波形类似的循环伏安曲线;在KCl和K2SO4介质中牙片的腐蚀速度无显著差异;2.0V恒电位腐蚀牙片8h后,阳极池本体溶液pH值由7.0平均下降到3.87,阴极池则由7.0平均升高到10.65。结论 在外电场作用下,牙片的阳极腐蚀与介质无关;水的阳极氧化引起阳极区氢离子浓度升高,致使牙齿发生酸溶是电化学人工龋形成的主要决定因素。 相似文献
99.
Abstract – This study describes the early microbial colomization of teeth by the use of light-and transmission electron microscopy. Six dental students carried a total of 60 test pieces of unerupted enamel and root surface in intraoral acrylic appliances for 4, 8, 12, 24 and 48 h, during which periods oral hygiene was abandoned. Pronounced variations were recorded in structure and thickness of the pellicle across the individual surfaces of both dental tissues. Bacterial single-cell colonization increased the electron density of the adjoining pellicle. Micro-colonies of bacteria were observed in relation to enamel surface irregularities such as perikymata, while the distribution on root surfaces appeared incidental. Root surfaces were generally colonized by thicker deposits than homologous enamel surfaces although the structural composition of the microbiota was similar. Gram-positive bacteria with thick cell walls appeared in coccoid or rod-shaped configurations depending on the age of the bacterial deposit. These bacteria were further characterized by selective invasion between collagen fibers. After 48 h the complexity of the microbiota was increased by the establishment of new bacterial species in the superficial layer. It is concluded that the pattern and composition of the early microbiota on teeth is more complex and variable than hitherto assumed. 相似文献
100.
Splints made of wire and composite: an investigation of lateral tooth mobility in vivo 总被引:1,自引:0,他引:1
Abstract In 103 posttraumatic splints, lateral tooth mobility was measured with Periotest immediately before and after the routine splint removal. The splints were made of composite resin and an 0.017×0.025″ orthodontic steel wire. 481 teeth were measured. A statistic evaluation revealed that the immobilisation effect did not exceed normal tooth firmness. Fixation to one neighbouring tooth had less effect than fixation to two. Adjacent tooth gaps reduced the effect. Splint extensions had no influence. With the use of the Periotest device, more than 50% of all teeth with a true mobility of 20 Periotest-units or more were detectable as mobile in spite of the fixed splint. 相似文献