全文获取类型
收费全文 | 48732篇 |
免费 | 4037篇 |
国内免费 | 3102篇 |
专业分类
耳鼻咽喉 | 421篇 |
儿科学 | 770篇 |
妇产科学 | 653篇 |
基础医学 | 6361篇 |
口腔科学 | 780篇 |
临床医学 | 6343篇 |
内科学 | 7795篇 |
皮肤病学 | 538篇 |
神经病学 | 2902篇 |
特种医学 | 1454篇 |
外国民族医学 | 17篇 |
外科学 | 5715篇 |
综合类 | 6918篇 |
现状与发展 | 5篇 |
一般理论 | 7篇 |
预防医学 | 3135篇 |
眼科学 | 1280篇 |
药学 | 4832篇 |
31篇 | |
中国医学 | 2021篇 |
肿瘤学 | 3893篇 |
出版年
2024年 | 153篇 |
2023年 | 705篇 |
2022年 | 1754篇 |
2021年 | 2236篇 |
2020年 | 1637篇 |
2019年 | 1584篇 |
2018年 | 1642篇 |
2017年 | 1417篇 |
2016年 | 1317篇 |
2015年 | 1953篇 |
2014年 | 2427篇 |
2013年 | 2196篇 |
2012年 | 3319篇 |
2011年 | 3758篇 |
2010年 | 2211篇 |
2009年 | 1748篇 |
2008年 | 2429篇 |
2007年 | 2448篇 |
2006年 | 2320篇 |
2005年 | 2349篇 |
2004年 | 1616篇 |
2003年 | 1561篇 |
2002年 | 1338篇 |
2001年 | 1176篇 |
2000年 | 1186篇 |
1999年 | 1285篇 |
1998年 | 674篇 |
1997年 | 725篇 |
1996年 | 536篇 |
1995年 | 500篇 |
1994年 | 430篇 |
1993年 | 323篇 |
1992年 | 470篇 |
1991年 | 507篇 |
1990年 | 471篇 |
1989年 | 418篇 |
1988年 | 382篇 |
1987年 | 327篇 |
1986年 | 314篇 |
1985年 | 289篇 |
1984年 | 172篇 |
1983年 | 155篇 |
1982年 | 94篇 |
1981年 | 98篇 |
1979年 | 102篇 |
1974年 | 89篇 |
1973年 | 95篇 |
1972年 | 87篇 |
1970年 | 75篇 |
1969年 | 77篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
腰椎节段形态对峡部、小关节应力及小关节接触力影响的有限元分析 总被引:1,自引:0,他引:1
目的:探讨腰椎形态结构变化对峡部裂性滑脱及小关节退变的作用和意义。方法:采用改良的“非种子区域分割方法”及非平行“最佳切割平面”等一系列新型计算机辅助设计(CAD)方法精确建立包括椎间盘高度、腰椎小关节角、椎间盘前凸角改变的L4~L5活动节段有限元模型;在2700N轴向压缩载荷条件下,分别对各有限元模型的峡部、小关节应力、小关节接触力以及椎间盘负载进行测试。结果:压缩载荷下,腰椎活动节段峡部、小关节等效应力及小关节接触力随椎间盘高度的减小而减小,随小关节角的增大而增加,随椎间盘前凸角的增加而减小。结论:椎间盘高度、腰椎小关节角、椎间盘前凸角等形态结构变化对腰椎节段有限元模型的峡部、小关节应力及小关节接触力有明显的影响。提示腰椎峡部应力性骨折及小关节退变的发生与椎间盘高度、腰椎小关节角、椎间盘前凸角等解剖形态因素有关。 相似文献
42.
S D Phinney A B Tang C R Waggoner R G Tezanos-Pinto P A Davis 《The American journal of clinical nutrition》1991,53(6):1404-1410
Serum lipoproteins, body composition, and adipose cholesterol contents of six obese women were studied during and after major weight loss by very-low-calorie diets (VLCDs). Subjects started at 168 +/- 11% of ideal body weight, lost 30.3 +/- 3.7 kg in 5-7 mo, followed by 2+ mo in weight maintenance. Serum cholesterol fell from a prediet (baseline) value of 5.49 +/- 0.32 to 3.62 +/- 0.31 mmol/L (P less than 0.01) after 1-2 mo of VLCDs (nadir), after which it rose to 5.95 +/- 0.36 mmol/L (peak, P less than 0.01 compared with nadir and baseline) as weight loss continued. With weight maintenance, serum cholesterol fell to 4.92 +/- 0.34 mmol/L (P less than 0.05 compared with peak). Adipose cholesterol content did not change in peripheral (arm and leg) biopsy sites but rose significantly in abdominal adipose tissue with weight loss. We conclude that major weight loss was associated with a late rise in serum cholesterol, possibly from mobilization of adipose cholesterol stores, which resolved when weight loss ceased. 相似文献
43.
44.
A. Sh. Oganisyan A. S. Noravyan I. A. Dzhagatspanyan I. M. Nazaryan A. G. Akopyan 《Pharmaceutical Chemistry Journal》2007,41(11):588-590
New methods for the synthesis of 4-substituted 6,7-dihydro-7,7-dimethyl-5-oxo-9H-pyrano-[4′,3′: 4,5]-thieno[3,2-e]imidazo[1,2-a]pyrimidines
and their hydrochlorides are developed. The anticonvulsant and tranquilizer properties of newly synthesized compounds have
been studied.
__________
Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 41, No. 11, pp. 22–24, November, 2007. 相似文献
45.
A ten-year experience with 106610 diagnostic esophagogastroduodenoscopies provided evidence of a 0.03% rate of relevant complications and 2.38% mortality. Out of 39 patients with endoscopy-related complications 5 were operated on: 4 had esophageal perforations, 1 had hemorrhage following biopsy of the ulcer. Out of 7384 therapeutic and operative endoscopies none were associated with lethal outcome. Surgery was avoided either. Complications developed in 45 patients (0.036%): in 44 patients hemorrhages occurred after electroexcision of the polyps. 相似文献
46.
灯盏花素注射液对大鼠脑缺血-再灌注脑损害的凋亡抑制作用 总被引:9,自引:0,他引:9
目的:研究灯盏花素(Bre)对大鼠脑缺血-再灌注引起脑损伤的保护作用。方法:实验选用40只雄性Wistar大鼠,大鼠被随机分成5组:假手术组、对照组、硫酸镁(Mg-SO4)治疗组、灯盏花素治疗和组。自大鼠颈总动脉插入尼龙线栓栓塞大脑中动脉,造成大脑缺血,拔出线栓实现再灌注。脑缺血10min后给予75mg/kg和50mg/kgBre及30mg/kgMgSO4,分别于脑缺血1h,再灌注2h,5h和23h分别进行神经病学评分,并于脑缺血1h,再灌注23h时测定脑梗死面积,用TUNEL法和免疫组化法分别检测脑组织凋亡细胞和Caspase-3阳性细胞的变化。结果:灯盏花素降低脑缺血-再灌注大鼠神经病学评分,缩小脑梗死面积,降低脑组织凋亡细胞和Caspase-3阳性细胞数量,其作用强于硫酸镁。结论:灯盏花素通过抑制细胞凋亡可显著保护大脑缺血-再灌注引起的脑损伤,其作用优于单用硫酸镁。 相似文献
47.
Fengxiu Ouyang Binyan Wang Lester M. Arguelles Xiping Xu Jianhua Yang Zhiping Li Liuliu Wang Xue Liu Genfu Tang Houxun Xing Craig Langman Xiaobin Wang 《Archives of osteoporosis》2007,2(1-2):29-43
Summary We prospectively examined bone growth patterns in 894 children aged 6–17 years at the baseline visit, with a 6-year follow-up.
Results show bone “tracking” over a six-year interval and sexual dimorphism of bone attained levels and timing of peak bone
growth. Our findings underscore childhood and adolescence as critical periods for building bone and developing gender differences.
Introduction Bone growth patterns were prospectively examined in 894 Chinese children (496 males), aged 6–17 yrs, from a population-based
twin cohort. Whole-body bone area (BA), bone mineral content (BMC), and bone mineral density (BMD) were measured by DEXA at
baseline and a 6-yr follow-up.
Methods Graphic smoothing plots and generalized estimating equations were used to model bone attained levels, growth, and “tracking”.
Results Attained levels of BMC and BA increased curvilinearly with age. Male attained levels were higher than females after age ∼15 yr,
but BMD was lower between 13–17 yrs (Tanner stage I to IV). In both genders, peak BMC and BMD growth lagged ∼2 yrs behind
peak BA growth, which lagged 2 yrs behind peak height growth. Peak bone growth occurred 1–3 yrs later in males. Over the 6-yr
follow-up, all bone measurements “tracked”, but “shifting” across ranks also occurred, and baseline tertile ranking influenced
bone growth. Females with early menarche had higher attained levels than females with late menarche at age 12–13 yrs.
Conclusion Our findings confirm and expand previous studies on peak bone growth conducted in Caucasian cohorts, particularly sexually
dimorphic and maturational effects. The significant “tracking” of bone measurements in this 6-yr follow-up study underscores
the importance that osteoporosis prevention should begin in childhood and adolescence.
Fengxiu Ouyang and Binyan Wang contributed equally to this article.
Source(s) of support: This study is supported in part by grant R01 HD049059, R01 HL0864619 and R01 AR045651 from the National
Institute of Health and by the Food Allergy Project. 相似文献
48.
49.
L. Whittaker A. A. Faraj D. Tang 《European journal of orthopaedic surgery & traumatology : orthopedie traumatologie》2007,17(5):479-481
Chronic, recurrent, multifocal osteomyelitis (CRMO) is an obscure disease of bone, occurring in children. It appears to be an inflammatory condition with no obvious microbiological cause. Current treatments of antibiotics and anti-inflammatory medication appear to have limited success. This case report looks at two separate cases of CRMO where partial resection of the affected bone—the clavicle—leads to complete resolution of symptoms and regrowth of the excised bone. 相似文献
50.