全文获取类型
收费全文 | 8329篇 |
免费 | 338篇 |
国内免费 | 147篇 |
专业分类
耳鼻咽喉 | 52篇 |
儿科学 | 151篇 |
妇产科学 | 35篇 |
基础医学 | 942篇 |
口腔科学 | 73篇 |
临床医学 | 896篇 |
内科学 | 1134篇 |
皮肤病学 | 53篇 |
神经病学 | 1015篇 |
特种医学 | 399篇 |
外科学 | 1331篇 |
综合类 | 1026篇 |
预防医学 | 329篇 |
眼科学 | 137篇 |
药学 | 527篇 |
3篇 | |
中国医学 | 335篇 |
肿瘤学 | 376篇 |
出版年
2023年 | 131篇 |
2022年 | 224篇 |
2021年 | 257篇 |
2020年 | 253篇 |
2019年 | 220篇 |
2018年 | 212篇 |
2017年 | 213篇 |
2016年 | 194篇 |
2015年 | 191篇 |
2014年 | 487篇 |
2013年 | 525篇 |
2012年 | 455篇 |
2011年 | 518篇 |
2010年 | 372篇 |
2009年 | 419篇 |
2008年 | 417篇 |
2007年 | 430篇 |
2006年 | 359篇 |
2005年 | 318篇 |
2004年 | 320篇 |
2003年 | 263篇 |
2002年 | 189篇 |
2001年 | 182篇 |
2000年 | 161篇 |
1999年 | 136篇 |
1998年 | 105篇 |
1997年 | 135篇 |
1996年 | 114篇 |
1995年 | 87篇 |
1994年 | 77篇 |
1993年 | 65篇 |
1992年 | 78篇 |
1991年 | 51篇 |
1990年 | 57篇 |
1989年 | 47篇 |
1988年 | 42篇 |
1987年 | 52篇 |
1986年 | 54篇 |
1985年 | 49篇 |
1984年 | 50篇 |
1983年 | 16篇 |
1982年 | 32篇 |
1981年 | 29篇 |
1980年 | 28篇 |
1979年 | 24篇 |
1978年 | 20篇 |
1977年 | 22篇 |
1975年 | 19篇 |
1973年 | 27篇 |
1972年 | 22篇 |
排序方式: 共有8814条查询结果,搜索用时 0 毫秒
11.
T. Erhan Cosan Baki Adapinar Hamdi Cakli M. Kezban Gurbuz 《European archives of oto-rhino-laryngology》2006,263(4):327-330
The case of a child injured by a knitting needle penetrating transorbitally and intracranially, resulting in carotid cavernous fistula and pontine injury, is reported. After receiving medical and endovascular treatment, the only remaining abnormal neurological manifestation was right peripheral facial nerve palsy. The clinical sequences of events and the demonstration of a pontine lesion leading to peripheral facial palsy are presented. Facial nuclear injury with a penetrating trauma is an extremely rare condition. It is important to identify the anatomical regions injured in penetrating traumas. The lesions must be identified by computerized tomography, magnetic resonance imaging, clinical and laboratory investigation. 相似文献
12.
K. H. Vogelberg M. Mühl M. Köhler 《Journal of molecular medicine (Berlin, Germany)》1987,65(15):713-718
Summary Seventy-five diabetic and 40 nondiabetic subjects who where suffering from peripheral vascular disease were studied in order to determine whether the degree of the severity of their disease can be better calculated by Doppler ultrasound examinations of the peak velocity than by the systolic pressure of the peripheral bloodstream. In 46 examinations of normal controls the mean value of the peak velocity was 13.3±3.3 cm/s with a standard deviation of 15.4%±13.2% on one day and 16.1%±15.9% on different days. Considering patients with or without diabetes mellitus the velocity was significantly decreased in correlation to an increasing degree of severity of the vascular disease (P<0.001); however, the decrease was lower in diabetic than in nondiabetic subjects (6.9±2.8 vs 4.6±6.2,P<0.05). The systolic pressure hardly decreased, but remained higher in all stages of peripheral vascular disease of diabetics than in the nondiabetic subject (P<0.05 toP<0.005). There was a significant decrease of the systolic pressure only in diabetic subjects with the most advanced degree of the disease, i.e. stage IV (P<0.05).It is concluded from this study that Doppler ultrasound measurements of the peak velocity of the peripheral bloodstream are a useful parameter to calculate the degree of severity of the peripheral vascular disease. In addition, it is concluded than peak velocity is an even better prognostic indicator of peripheral vascular disease than is measurement of the systolic blood pressure at the feet.
Abkürzungen AVK periphere arterielle Verschlußkrankheit - USDI Ultraschall-Doppler-Index - MSBG maximale Blutströmungsgeschwindigkeit - HFV Herzfrequenzvariation 相似文献
Abkürzungen AVK periphere arterielle Verschlußkrankheit - USDI Ultraschall-Doppler-Index - MSBG maximale Blutströmungsgeschwindigkeit - HFV Herzfrequenzvariation 相似文献
13.
Elizabeth P. Eustis-Turf Joyce A. Benjamins Maurice J. Lefford 《Journal of neuroimmunology》1986,10(4):313-330
Sera from 43 leprosy patients were tested for antibodies that bound to normal human nerve. Thirty-eight percent showed positive staining as demonstrated by indirect immunofluorescence. Only 1 out of 30 control sera tested displayed similar staining. Western blots of myelin and neural intermediate filament (IF) proteins were tested with patient sera. Two of the anti-neural antibody (ANeAb)-positive leprosy sera bound to the P0 protein of PNS myelin. All 17 ANeAb-positive leprosy sera displayed 2 or more bands in the molecular weight range of Mr 45 000-55 000, when tested against IF proteins. One explanation for these findings is that leprosy patients produce antibodies to intermediate filament (IF) proteins released subsequent to the bacterial invasion of the peripheral nerves. The importance of these autoantibodies in the pathogenesis of leprosy is discussed. 相似文献
14.
外消旋聚乳酸复合神经生长因子缓释导管促周围神经再生的形态学研究 总被引:6,自引:2,他引:4
目的 建立外消旋聚乳酸复合神经生长因子(poly-D,L-lactic acid/nerve growth factor,PDLLA/NGF)可吸收性缓释导管桥接修复大鼠坐骨神经缺损的动物模型,观察复合导管对大鼠坐骨神经缺损再生的促进作用。方法利用溶剂挥发法制备PDLLA单纯导管和PDLLA/NGF缓释导管,每根缓释导管含NGF450U。SD大鼠40只随机分成4组,每组10只,切除中段坐骨神经10mm之后分别行自体神经移植(A组)、单纯导管桥接(B组)、单纯导管加一次性给药(C组)、PDLLA/NGF缓释导管桥接(D组)修复坐骨神经,除A组外,均保留10mm缺损。术后3个月观察神经再生情况,比较各组光镜、电镜及图像分析等指标。结果术后3个月导管与周围组织粘连松,并开始降解,但外形仍保持完整。再生神经均顺利通过导管腔,组织学观察A组和D组内神经纤维数目多,大小均匀,成熟良好;B组和C组纤维结缔组织多,神经纤维细小,髓鞘薄。图像分析显示除神经纤维计数D组高于A组外,A组和D组在纤维直径、轴突直径和髓鞘厚度方面差异均无统计学意义(P〉0.05),并明显优于B组和C组(P〈0.05)。结论 PDLLA/NGF缓释导管能够有效促进大鼠坐骨神经缺损再生,组织学观察指标接近自体神经移植。 相似文献
15.
Francisco J. Romero Juan Segura-Aguilar Elena Monsalve Carlos Hermenegildo Eberhard Nies Francisco J. Puertas Joaquí n Rom 《Neurotoxicology and teratology》1990,12(6):603-605
The present work tries to establish the antioxidant capacity of the peripheral nervous tissue of the rat, in terms of the enzymatic activities present in this tissue that either prevent the formation of activated species as the semiquinone radical (DT-diaphorase), protect against activated oxygen species (superoxide dismutase, glutathione peroxidase), conjugate natural toxic products or xenobiotics (glutathione S-transferases, especially the activity conjugating 4-hydroxy-nonenal), or complete the glutathione system metabolism (glutathione disulfide reductase, γ-glutamyl transpeptidase). All the activities studied are lower in this tissue than they are in liver, except for γ-glutamyl transpeptidase. The relevance of the results obtained and its possible relationship with different neuropathies is discussed. It is concluded that the peripheral nervous tissue is by far less protected than the liver against oxidative damage. 相似文献
16.
Emmanuel Ellie Anne Vital Andreas Steck Jean-Michel Boiron Claude Vital Jean Julien 《Journal of neurology》1996,243(1):34-43
We studied 33 patients presenting with a peripheral neuropathy associated with non-malignant anti-myelin-associated glycoprotein (MAG) IgM monoclonal gammopathy (MG) in an attempt to delineate their clinical, immunological, electrophysiological and pathological characteristics; we also reviewed our experience concerning long-term follow-up and therapy. Peripheral neuropathy associated with non-malignant anti-MAG IgM MG was observed mostly in males (sex ratio 7.2), and mean age at onset was 67 years (range 46–81). A predominantly sensory pattern was noted in more than 80% of cases, although some patients were affected by a predominantly motor peripheral neuropathy. Although disease progression was slow in most cases, 45% of patients suffered severe disability, and in 2 cases, the patient's death appeared to stem directly from the neuropathy. The electrophysiological findings were indicative of a demyelinating process in 90% of cases, and electron microscopic examination of nerve biopsy specimens demonstrated widening of the myelin lamellae in more than 95% of cases. Most of our patients showed a disappointing response to steroids and chemotherapy or plasma exchanges. Intravenous immune globulin, evaluated in 17 patients, had a transient, mostly subjective effect in 35% and led to a clear-cut improvement in 24% of cases. We did not observe any correlation between the severity of the clinical picture and the anti-sulphoglucuronyl paragloboside antibody titre; in individual cases, clinical improvement occurred without lowering of IgM levels. Although the severity and the rate of progression may greatly vary from patient to patient, the combination of clinical, electrophysiological and pathological features delineates a characteristic pattern in peripheral neuropathy associated with non-malignant anti-MAG IgM MG. 相似文献
17.
将大鼠的腓总神经切断后,进行如下4组实验:A.原位3mm间隙动脉套桥接,B.原位断端外膜缝合,C远侧断端旋转180°3mm间隙动脉套桥接,D远侧端旋转180°外膜缝合。术后12周的电生理学,组织学评价显示,B组神经再生效果最佳,A、C两组接近B组,而D组较差。 相似文献
18.
G. Van Goethem J.-J. Martin A. Lfgren I. Dehaene P. Tack M. Van Zandycke D. Ververken C. Ceuterick C. Van Broeckhoven 《European journal of neurology》1997,4(5):476-484
We studied 14 patients from three unrelated Belgian pedigrees with a familial mitochondrial disorder and multiple deletions of mitochondrial DNA (mtDNA). In one family with an oculopharyngeal presentation there is a clear autosomal dominant inheritance. Progressive external ophthalmoplegia (PEO), “ragged red fibres” (RRF) and multiple deletions of mtDNA are common to all three families. Therefore a diagnosis of autosomal dominant progressive ophthalmoplegia with multiple deletions of mtDNA (adPEO) was made in one family at least. Our data confirm the previous observations that adPEO is a systemic disorder rather than a pure myopathy. In our pedigrees frequently associated features include axonal peripheral neuropathy, dysphagia, psychiatric illness, and sudden death. Mild ataxia, pes cavus and mitral valve prolapse with associated mitral insufficiency also occur. In some cases onset is atypical with neuropathy, adolescent onset myopathy or psychiatric illness. In such cases the common features of PEO and muscle weakness always complete the clinical phenotype later during the course of the disease. Biochemical studies on mitochondrial fractions prepared from one patient's muscle, revealed no abnormalities of respiratory chain enzyme activities. 相似文献
19.
Rolf Gronas B. Eng Peter G. Kalman MD Daryl S. Kucey MD Graham A. Wright PhD 《Journal of magnetic resonance imaging : JMRI》1997,7(4):637-643
Flow-independent angiography (FIA), an approach that isolates arterial blood using MR relaxation characteristics rather than flow effects, was evaluated for application in peripheral vascular disease (PVD). First, pilot studies were conducted in which FIA coronal projection images were obtained from controls and symptomatic patients with PVD to assess clinical utility. All control images corresponded to the expected leg arterial anatomy with little interference from deep veins (one of five) and muscle (zero of five). Superficial venous signal was less well suppressed in comparison to deep veins (four of five). Images of symptomatic patients were less consistent with difficulty suppressing muscle and deep venous signal in some cases and edema when present. We then compared T2 values for muscle (T2m, tibialis anterior), arterial blood (femoral and popliteal arteries), and venous blood (femoral, popliteal, and saphenous veins) in controls (n = 8) and symptomatic patients with intermittent claudication (n = 5) or ischemic rest pain (n = 7). Changes in T2 measurements of various tissues accounted for poorer contrast in symptomatic patients. Patients with ischemic rest pain had significantly higher T2m compared with controls (T2m = 39.3 ± 2.1 (1 standard error of the mean [SEM]) versus 30.9 ± .4, P < .01). For all measurements, other than saphenous vein, variances were greater in symptomatic patients. To realize the inherent advantages of FIA for this clinical application, additional work on suppression of signals from muscle, veins, and edema is required. One promising approach involves shifting from projection images to three-dimensional acquisitions for improved tissue suppression. 相似文献
20.
目的 :评价平板式全数字心血管造影机在周围血管及非血管介入中的应用价值。方法 :对平板探测器(FPDD)X线成像与影像增强器 电视 (IITV)X线成像在动态范围、成像均匀性、对比度线性、对比分辨率等图像质量指标的检测及比较。随机选择上述两机型在周围血管及非血管介入诊疗病例图像资料各 6 0例 ,由三名高年资医师对其图像质量进行综合评价 ,记录评价结果 ,并进行比较。结果 :FPDD成像在动态范围、成像均匀性、对比度线性、对比分辨率等图像质量指标均优于IITV成像 ;在人体各部位周围血管及非血管介入诊疗中的图像综合评价结果也优于IITV成像。结论 :平板式全数字化心血管造影机不仅适用于心血管介入 ,同时能满足全身各部位周围血管及非血管介入诊疗的需要。 相似文献