全文获取类型
收费全文 | 334046篇 |
免费 | 28858篇 |
国内免费 | 21650篇 |
专业分类
耳鼻咽喉 | 3046篇 |
儿科学 | 3442篇 |
妇产科学 | 4942篇 |
基础医学 | 40829篇 |
口腔科学 | 5574篇 |
临床医学 | 46368篇 |
内科学 | 50640篇 |
皮肤病学 | 3137篇 |
神经病学 | 18995篇 |
特种医学 | 12127篇 |
外国民族医学 | 213篇 |
外科学 | 34196篇 |
综合类 | 50305篇 |
现状与发展 | 76篇 |
一般理论 | 20篇 |
预防医学 | 19852篇 |
眼科学 | 9771篇 |
药学 | 33195篇 |
425篇 | |
中国医学 | 17905篇 |
肿瘤学 | 29496篇 |
出版年
2025年 | 94篇 |
2024年 | 4375篇 |
2023年 | 6769篇 |
2022年 | 13517篇 |
2021年 | 16708篇 |
2020年 | 13067篇 |
2019年 | 11635篇 |
2018年 | 11495篇 |
2017年 | 10067篇 |
2016年 | 9511篇 |
2015年 | 14428篇 |
2014年 | 17864篇 |
2013年 | 15370篇 |
2012年 | 22872篇 |
2011年 | 25804篇 |
2010年 | 15901篇 |
2009年 | 12248篇 |
2008年 | 17012篇 |
2007年 | 17018篇 |
2006年 | 17048篇 |
2005年 | 16773篇 |
2004年 | 10661篇 |
2003年 | 9755篇 |
2002年 | 8439篇 |
2001年 | 7464篇 |
2000年 | 8271篇 |
1999年 | 9007篇 |
1998年 | 5474篇 |
1997年 | 5499篇 |
1996年 | 4338篇 |
1995年 | 3925篇 |
1994年 | 3213篇 |
1993年 | 2097篇 |
1992年 | 2827篇 |
1991年 | 2415篇 |
1990年 | 2118篇 |
1989年 | 1861篇 |
1988年 | 1563篇 |
1987年 | 1353篇 |
1986年 | 1107篇 |
1985年 | 912篇 |
1984年 | 527篇 |
1983年 | 373篇 |
1982年 | 242篇 |
1981年 | 238篇 |
1980年 | 190篇 |
1979年 | 221篇 |
1977年 | 89篇 |
1974年 | 102篇 |
1973年 | 83篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
11例10—14岁骨性Ⅲ类错He患者的疗效观察 总被引:2,自引:2,他引:2
目的 观察联合应用前方牵引和上颌快速扩弓治疗10-14岁骨性安氏Ⅲ类错He患者的临床效果。方法 以11例10-14岁骨性Ⅲ类错He患者为观察组,32例替牙早期骨性Ⅲ类错He患者为对照组,两组均采用联合应用前方牵引和上颌快速扩弓装置治疗,平均治疗时间6个月,治疗前后均拍摄头影侧位片,并采用一种新的头颅参照系统,对结果进行分析比较,评价治疗效果。结果 两组患者均发生上颌骨前移,下颌骨向下后旋转,向前生长受限,观察组前牙覆盖增加5.3mm,骨性变化占51%,牙性变化占49%;其中,9例患者前牙达到正常覆He、覆盖关系,磨牙中性关系,2例患者前牙达到浅覆He,浅覆盖关系,后牙中性偏近中关系。结论 联合应用前方牵引和上颌快速扩弓治疗10-14岁轻中度骨性反He患者有较好疗效,可减轻畸形程度,避免手术治疗,最大程度地改善患者的软硬组织关系。 相似文献
122.
上颌半口义齿金属基托的计算机辅助设计 总被引:5,自引:0,他引:5
目的 :在自行重建无牙颌三维数据模型的基础上设计上颌半口义齿金属基托数字模型。方法 :采用数控铣床及新型层析数据采集系统 ,通过对标准无牙颌模型的层切 ,二维轮廓数据获取及计算 ,重建无牙颌模型 ,在此数据基础上 ,通过SURFACER软件 ,设计上颌半口义齿金属基托。结果 :获得无牙颌三维数据及上颌金属基托的数据文件。结论 :通过新型层析系统可以实现对无牙颌三维建模 ;在此基础上设计的三维数字基托可为进一步激光立体成形制作奠定基础。 相似文献
123.
目的:了解类骨质羟基磷灰石(OHA)的生物相容性,初步探讨其作为骨替代材料的可行性。方法:12只新西兰白兔随机分为4组,在双侧股骨内侧髁形成9mm×4mm×5mm大小的缺损,分别植入OHA和对照材料,术后2、4、8、12周取标本,进行大体标本、X线、组织学切片、扫描电镜观察及成骨面积的定量分析。结果:实验组成骨细胞易于粘附、生长、增殖,骨小梁形成钙化早,新骨面积百分比高于对照组,差异有统计学意义。结论:类骨质羟基磷灰石是一种良好的骨替代材料,具有广阔的应用前景。 相似文献
124.
Bleaching tetracycline-stained teeth is the most challenging form of tooth lightening. This article reports on 44 subjects who bleached their tetracycline-stained teeth for 6 months using trays with reservoirs overnight in a half-mouth designed study and 2 of 3 different concentrations of carbamide peroxide (10%, 15% or 20%). The subjects were followed for 5 years. The area evaluated was the middle third of the teeth. More than 55% of tooth lightening occurred within 1 month; after 5 years, more than 65% of the maximum tooth whitening remained for all 3 gel concentrations. Tooth whitening can be accomplished with any of the 3 concentrations used. 相似文献
125.
Chiao-Kang Chao Long-Chang Chang Shyun-Yen Liu Jaang-Jiun Wang 《Journal of oral and maxillofacial surgery》2002,60(10):1131-1134
PURPOSE: This report evaluates the wound healing process of buccal fat pad (BFP) grafted on a defect of the buccal mucosa for oral submucous fibrosis (OSF). PATIENTS AND METHODS: Sixteen patients with limitation of mouth opening under the diagnosis of OSF were surgically treated by cutting the fibrotic bands on the buccal mucosa (10 bilateral and 6 unilateral). The defects created were then covered by a BFP graft. The bulging BFP was trimmed postoperatively on a weekly basis until it was fully epithelialized. The specimens were stained and examined microscopically. RESULTS: Inflammatory cell infiltrate, blood vessel congestion, and fibrinous exudates covering the BFP were obvious by week 2. At week 3, blood vessel congestion and fat cell number decreased markedly. Evidence of stratified squamous epithelium with parakeratosis was seen in the margin of the BFP graft. At week 4, the number of fat cells decreased significantly and the original BFP was almost completely replaced by granulation tissue. The original BFP was fully covered by stratified squamous epithelium by week 5. CONCLUSIONS: The BFP graft has been widely used for covering exposed defects created by fibrotic band excision for the improvement of mouth opening limitation. The healing process was documented microscopically by weekly observation. 相似文献
126.
Mineral loss in early caries cannot be measured without invasive procedures. To quantify mineral loss without sectioning the tooth, one must determine the optical scattering of the enamel. Using enamel white-spot lesions, we hypothesize that the optical scattering power (Sp) of the demineralized enamel would provide a quantitative estimate of mineral loss. Enamel slabs were demineralized to produce artificial white spots. The data were acquired by means of a Charge-Coupled Device (CCD) camera and image-processing software. For the purpose of comparison, mineral loss (deltaZ) of the demineralized samples was determined by the use of a microhardness approach after the samples were sectioned. The scattering power correlated well with deltaZ (r2 = 0.82). In contrast, simple reflectance of the demineralized samples correlated poorly with deltaZ (r2 = 0.22). The validity of using scattering power to measure demineralization has been confirmed by a three-dimensional Monte Carlo Simulation. 相似文献
127.
为探索评价复合树脂磨耗的最佳方法,本研究采用直接临床评价法和间接模型比较法,对以4种复合树脂修复的93例磨牙面洞修复体进行了3年的评估。结果表明,直接法对修复体早期磨耗的评估不敏感,但对修复体其它方面的评价目前仍为首选;间接法评估修复体的磨耗更准确、敏感,量化的磨耗值便于统计学分析;直接法与间接法相结合可更客观,更全面地评价复合树脂修复体的临床效果。 相似文献
128.
干燥综合征患者唾液pH值、电解质测定的诊断意义初步探讨 总被引:1,自引:0,他引:1
目的:探讨唾液生化指标测定对初步诊断干燥综合征的临床价值。方法:分为干燥综合征病变组和正常对照组,吐取法采集混合唾液,测定唾液pH值、Na 、K 浓度,计算Na /K ,Na 、K 单位时间分泌总量。t检验统计分析。结果:干燥综合征病变组唾液Na 、K 浓度、Na /K 明显高于正常对照组,与正常对照组相比,病变组K 单位时间分泌总量明显下降,pH值显著降低。Na 浓度、Na /K 敏感性、特异性均较高,pH值特异性较高,K 单位时间分泌总量敏感性、特异性一般。结论:唾液检查是一种简便、准确、无创的检查手段,干燥综合征患者唾液pH值、电解质具有特征性,其综合评定对初步筛选干燥综合征有一定临床价值。 相似文献
129.
Multiple odontogenic keratocysts (OKCs) are principle features of nevoid basal cell carcinoma syndrome (NBCCS; Gorlin-Goltz syndrome). NBCCS is a genetic disorder transmitted by an autosomal dominant gene with variable expressivity, which is important to recognize when a patient has multiple OKCs. The cysts of the jaws are among the most common findings. Another feature is a certain appearance of the face, such as: large calvaria, high-arched eyebrows, broad nasal root, and mild hypertelorism. Before-therapy diagnosis is, therefore, as important as after-therapy diagnosis. Genetic counseling and examination may also be indicated. The purpose of this paper was to present a family case report of nevoid basal cell carcinoma syndrome with multiple odontogenic keratocysts. The features identified by these combined clinical, imaging, and histologic findings are described, along with a brief mention of the family history and a review of the literature. 相似文献
130.
口腔颌面部恶性肿瘤病人可溶性白介素2受体的检测 总被引:3,自引:0,他引:3
本试验采用ELLSA法检测了60例口腔颌面部恶性肿瘤病人,21例口腔颌面部良性肿瘤病人,30例正常人的sIL-2R水平。结果:恶性肿瘤病人sIL-ZR水平较良性肿瘤病人较正常人水平明显升高(P<0.001),良性肿瘤病人与正常人间无差异(P>0.05),且sIL-2R水平与病理分级及临床分期有关。sIL-2R作为监视机体免疫状态的一种指标可帮助诊断分析、病情监测及预后评估。 相似文献