全文获取类型
收费全文 | 11781篇 |
免费 | 654篇 |
国内免费 | 282篇 |
专业分类
耳鼻咽喉 | 270篇 |
儿科学 | 662篇 |
妇产科学 | 1646篇 |
基础医学 | 1669篇 |
口腔科学 | 249篇 |
临床医学 | 1292篇 |
内科学 | 1019篇 |
皮肤病学 | 34篇 |
神经病学 | 390篇 |
特种医学 | 741篇 |
外科学 | 1943篇 |
综合类 | 1353篇 |
现状与发展 | 1篇 |
预防医学 | 605篇 |
眼科学 | 28篇 |
药学 | 571篇 |
2篇 | |
中国医学 | 159篇 |
肿瘤学 | 83篇 |
出版年
2024年 | 10篇 |
2023年 | 122篇 |
2022年 | 213篇 |
2021年 | 293篇 |
2020年 | 367篇 |
2019年 | 321篇 |
2018年 | 360篇 |
2017年 | 370篇 |
2016年 | 362篇 |
2015年 | 357篇 |
2014年 | 731篇 |
2013年 | 1006篇 |
2012年 | 591篇 |
2011年 | 636篇 |
2010年 | 615篇 |
2009年 | 637篇 |
2008年 | 598篇 |
2007年 | 562篇 |
2006年 | 560篇 |
2005年 | 487篇 |
2004年 | 438篇 |
2003年 | 354篇 |
2002年 | 305篇 |
2001年 | 257篇 |
2000年 | 233篇 |
1999年 | 207篇 |
1998年 | 166篇 |
1997年 | 172篇 |
1996年 | 131篇 |
1995年 | 150篇 |
1994年 | 132篇 |
1993年 | 97篇 |
1992年 | 68篇 |
1991年 | 90篇 |
1990年 | 71篇 |
1989年 | 75篇 |
1988年 | 67篇 |
1987年 | 62篇 |
1986年 | 47篇 |
1985年 | 59篇 |
1984年 | 66篇 |
1983年 | 36篇 |
1982年 | 58篇 |
1981年 | 43篇 |
1980年 | 28篇 |
1979年 | 26篇 |
1978年 | 27篇 |
1977年 | 12篇 |
1976年 | 9篇 |
1975年 | 12篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
91.
目的 探究依达拉奉联合瑞舒伐他汀治疗心源性脑梗死的疗效及对血清趋化因子12(CXCL12)、泛素C末端水解酶L1(UCH-L1)、人类软骨糖蛋白-39(HC-gp39)水平的影响。方法 选取2020年3月—2022年4月达州市中心医院收治的90例心源性脑梗死患者作为研究对象,随机分为对照组和观察组,各45例。对照组给予瑞舒伐他汀治疗,观察组给予依达拉奉联合瑞舒伐他汀治疗。比较两组疗效、CXCL12、UCH-L1、HC-gp39、血液流变学指标、血脂水平及美国国立卫生研究院脑卒中量表(NIHSS)评分。结果 观察组总有效率高于对照组(P <0.05)。观察组治疗前后血清CXCL12、UCH-L1、HC-gp39水平的差值高于对照组(P <0.05)。观察组治疗前后全血低切黏度、全血高切黏度及纤维蛋白原水平的差值高于对照组(P <0.05)。观察组治疗前后TC、TG、LDL-C水平的差值高于对照组(P <0.05)。观察组治疗前后NIHSS评分的差值高于对照组(P <0.05)。结论 依达拉奉联合瑞舒伐他汀治疗心源性心肌梗死可有效提高患者临床疗效,改善血液流变学指标、血脂、神经功能及炎症反应。 相似文献
92.
《The Knee》2022
BackgroundPatellofemoral joint cartilage defects are difficult to treat due to their unique thickness and topography.PurposeTo report the postoperative outcomes of patients age 21 and younger treated with particulated juvenile allograft cartilage (PJAC) for full-thickness cartilaginous defects of the patellofemoral joint. The primary aim was to report surgical outcomes and complication rates, as well as return to sport activity. A secondary aim was to provide objective scores of defect restoration by magnetic resonance imaging (MRI) assessment.MethodsA retrospective review of all PJAC cases conducted between 2012 and 2019 at a single tertiary care urban musculoskeletal institution was conducted. Patients 21 years old or younger with minimum clinical follow up of 1 year and postoperative MRI at a minimum of 6 months were included. Cartilage restoration by MRI was independently assessed using the International Cartilage Repair Society’s (ICRS) standardized system.ResultsThirty four patients, 36 knees, were included, with mean age 16.1 ± 3.1 years old. Return to sport rate among patients who participated in a sport preoperatively was 100%. On independent MRI assessment, two thirds of defects achieved an overall grade of normal or nearly normal, while 28 patients (78%) had majority defect fill. Primary graft failure occurred in two cases and one patient experienced a surgical complication.ConclusionRestoration of patellofemoral chondral defects in young patients with particulated juvenile allograft results in satisfactory short-term outcomes and postoperative MRI appearance, along with high rates of return to sport and low rate of complications and graft failure.What is known about the subject: Patellofemoral joint cartilage defects are difficult to treat due to their unique thickness and topography. Several cartilage restoration techniques are available, but these rarely achieve the same mechanical properties as native hyaline cartilage. PJAC is a cell-based technique that has demonstrated promise since its introduction in 2007.What this study adds to existing knowledge: This series of patients adds the largest single cohort of pediatric and adolescent patients who receive PJAC for defects of the patellofemoral joint. Surgeons treating patients in this age group should be aware of every technique, and their respective outcomes. 相似文献
93.
目的:探讨保留甲状软骨膜对全喉切除手术进程和病人术后恢复情况的影响。方法:在甲状软骨膜下游离甲状软骨并切断其上角。不结扎和切断舌骨下肌群和喉上动脉。保留之甲状软骨膜用以加强修复咽壁黏膜。结果:本组病例较经典全喉切除术手术时间缩短30min以上。手术中出血在100ml以下。患者术后第2d下床活动,第4d开始进食流质。手术创口均一期愈合。结论:全喉切除术中保留甲状软骨膜可有效地简化手术步骤,减少创伤和出血。利用甲状软骨膜加强咽壁黏膜缝合口,进一步减少了咽漏的发生. 相似文献
94.
1519例胎儿心电图的临床价值和相关因素分析 总被引:1,自引:0,他引:1
目的对1519例胎儿全部实行常规胎儿心电图(FECG)监测工作,探讨胎儿心电图应用情况,并对异常FECG结合临床,进行临床原因分析.方法采用随机湘样方法,应用杭州产FECG-D型胎儿心电图分析仪进行监测.结果发现采用横导联方式进行监测检出率为53.5%:在孕22w进行监测检出率为45.8%;异常FECG检出率为7.64%.结论对1519例FECG的监测发现采用横导联方式并在孕22w~26w期间进行监测检出率最高、波形效果好.并对监测发现的导致FECG异常改变的临床原因与胎儿宫内窘迫的关系进行浅要分析. 相似文献
95.
Tiniakos D Anagnostou V Stavrakis S Karandrea D Agapitos E Kittas C 《Anatomy and embryology》2004,209(1):41-47
We aimed to define, for the first time, the ontogeny of intrarenal innervation and to assess the distribution and nature of parenchymal nerves in the human fetal kidney. Our material consisted of routinely-processed renal tissue sections from 17 human fetuses, six of 20–24 gestational weeks (gw) and 11 of 25–40 gw, and three adults. We used immunohistochemistry with antibodies to the pan-neural markers neuron-specific enolase (NSE), neurofilaments (NF), PGP9.5, S100, and the adrenergic marker tyrosine hydroxylase (TH). NSE-, NF-, S100-, and PGP9.5-positive nerves, associated with arterial and venous vasculature, were identified in the renal cortex from 20 gw onwards, and their density appeared to increase with gestation, reaching adult levels at 28 gw. Most of the intrarenal nerves were TH-positive. Nerve fibers extended from the corticomedullary region to the outer cortex, reaching the renal capsule in the 3rd trimester. In detail, NSE-, NF-, S100-, PGP9.5-, and TH-immunoreactive fibers were observed in close apposition to the renal artery and its branches, occasionally reaching the afferent and efferent arteriole (3rd trimester). Nerve fibers were detected in close apposition to the juxtaglomerular apparatus in the 2nd and 3rd trimesters. In the renal medulla, NSE-, PGP9.5-, S100-, and TH-positive nerve fibers were detected close to tubular cells as early as 20 gw. However, their density gradually decreased during the 3rd trimester, and they were not observed in the medulla of the adult kidney. In conclusion, the human fetal kidney appears richly innervated during the 2nd and 3rd trimesters. There is a progressive increase in the density of parenchymal nerve fibers towards term from the corticomedullary region to the cortex. Most intrarenal nerves are adrenergic and have a predominant perivascular distribution, implying that renal innervation plays an important functional role during intrauterine life. 相似文献
96.
Summary The development of immunoreactive atrial natriuretic peptide (ANP) was studied in fetal hearts of spontaneously hypertensive (SHR) and compared to normotensive Wistar-Kyoto (WKY) rats. While SHR fetal hearts were noticeably less developed than those of WKY at 10 and 11 days gestation, both strains showed ANP immunoreactive cells in some but not all primitive heart tubes. At 12 days additional ANP immunoreactive cells appeared in formative trabeculae of the ventricle and atrium. ANP cells were also observed in the myogenic layer of the truncus and bulbus arteriosus and their derivatives from 11 through 16 days, but not at 18 days. In both strains, there were more ANP cells in the left ventricle than in right beginning at day 13. There were no obvious strain differences in the developmental pattern and timing of ANP producing cells. However, on the day of birth, staining was reduced in hearts from some WKY newborn pups compared with hearts from SHR newborns and ventricular staining was reduced in both strains when compared to fetal hearts. These observations indicate that ANP is one of the earliest peptide hormones produced and that the predisposition to genetic hypertension does not appear to influence the development of ANP. 相似文献
97.
目的:观测3~10月胎儿心脏重量及各表面结构的相关数值,探讨各结构随胎龄变化的规律和趋势。方法:取非正常分娩的、无心血管畸形的死亡胎儿心脏42例,甲醛固定后,按月龄分成8组,托盘天平称重后,测量表面各结构。结果:胎儿心脏重量为(6.31±5.53)g,其长径、宽径、前后径、周径、前室间沟径、后室间沟径、左缘径分别为(2.95±0.93)cm(、2.20±0.72)cm、(1.78±0.63)cm(、6.74±2.09)cm、(2.32±0.86)cm(、1.93±0.58)cm、(3.66±1.42)cm。结论:胎儿心脏外形各结构测量值随胎龄的增加而增大,且增大的速度不同。了解其正常数值对胎儿先天性心脏病的诊治有参考意义。 相似文献
98.
T. K. Huffaker B. D. Boss A. S. Morgan N. T. Neff R. E. Strecker M. S. Spence R. Miao 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1989,77(2):329-336
Summary A suspension of cells from embryonic day 21 fetal pig ventral mesencephalon was transplanted into the striatum of 20 immunosuppressed rats with 6-hydroxydopamine-induced lesions of the nigrostriatal dopamine pathway. Of these rats, 15 showed reduction of amphetamine-induced ipsilateral rotation by 9 weeks and complete reversal of rotation by 14–17 weeks. Animals maintained stable reversal of rotations (contralateral direction) until cessation of Cyclosporin A (CyA) treatment at 15–20 weeks. Within 4–9 weeks after CyA removal, these rats showed exclusively ipsilateral rotations during behavioral testing which were comparable to pre-transplant levels, suggesting that the grafts were rejected upon cessation of CyA treatment. Rats were sacrificed and tyrosine hydroxylase (TH) immunohistochemistry was performed at several time points, both on and off CyA, to examine a possible correlation between the degree of rotational behavior and the number of TH- positive surviving grafted cells. Staining showed large numbers (230–12,329) of TH-positive surviving cells in animals displaying a high degree of rotational correction (1.6 to -9.6 net ipsilateral rotations/min) after cessation of CyA treatment. Two control groups, those transplanted with nonneuronal cells from the pig ventral mesencephalon (n=5) and those receiving only daily CyA injections (n=4) showed no significant reduction of net ipsilateral rotations throughout the experiment. No TH-positive surviving cells were seen in the one non-neuronal transplant analyzed. This data demonstrates long-term retention of xenografted tissue with immunosuppression and its concomitant restoration of normal motor behavior in the rat model of Parkinson's disease. 相似文献
99.
Type IX collagen (CIX), a cartilage-specific glycoprotein, constitutes ≤ 10% of cartilage collagen. To ascertain whether CIX can induce arthritis as shown for type II and XI collagen (CII and CXI), outbred rats were sensitized with bovine, chick and human CIX; inbred rats, mice, and guinea pigs were sensitized with bovine CIX. Mice and guinea pigs proved resistant to arthritis, as did rats sensitized with CIX/Freund's incomplete adjuvant (FIA). Arthritis was seen in rats when 100 μg of Mycobacterium tuberculosis (Mtb) were added to FIA, but seldom with smaller doses of Mtb, suggesting the arthritis was adjuvant-induced. High levels of antibodies to rat CIX, containing complement-fixing subclasses, were detected in rat sera in addition to DTH and lymphocyte proliferation responses to rat CIX. Given the potential for CIX-induced disease, CIX-sensitized rats were injected intraperitoneally with lipopolysaccharide (LPS) to stimulate proinflammatory cytokine release, and intra-articularly with rat CIX to stimulate arthritis. LPS stimulation was ineffective; however, intra-articularly injected CIX produced transient synovitis. When rats with stable adjuvant arthritis were sensitized with CIX/FIA, significant increases in paw volume were measured compared with controls given CI/FIA. Immunohistochemical studies of actively and passively sensitized rats revealed deposits of CIX antibody, but not C3, at the joint margins where proteoglycan staining was weak. Together, these findings suggest that autoimmunity to CIX, in contrast to CII and CXI, is not directly pathogenic but may contribute to joint injury provided arthritis is initiated by an independent disease process. 相似文献
100.
The instability of membrane markers expressed by human monocytes and macrophages in culture 总被引:2,自引:0,他引:2
Surface markers were tested on freshly isolated human monocytes and following their in vitro maturation to macrophages. The markers tested were HLA-DR antigens, receptors for the Fc of IgG and complement as well as membrane markers defined by monoclonal antibodies. The results revealed a dynamic expression of some of the markers on monocytes which was influenced by several variables. The expression of the markers was modulated by the presence of different sera, by treatment with lymphokines and interferon and following the in vitro maturation of monocytes to macrophages. The most unstable marker was found to be the HLA-DR, which was modulated by all these variables. The 63D3 was affected by different sera and culture supernatant, as well as following the maturation of monocytes to macrophages, but not by lymphokines and interferon. One of the markers, the Mac 120, was found to be relatively stable and did not change significantly following the maturation of monocytes to macrophages. The Fc and complement receptors were also stable in their expression under these conditions, but were probably partially blocked in the presence of human serum. These results indicated that at least some of the heterogeneity related to the monocyte population was probably not due to the occurrence of stable subsets of cells, but rather to reversible changes in marker expression. 相似文献