全文获取类型
收费全文 | 1780篇 |
免费 | 87篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 227篇 |
妇产科学 | 11篇 |
基础医学 | 103篇 |
口腔科学 | 41篇 |
临床医学 | 79篇 |
内科学 | 39篇 |
皮肤病学 | 75篇 |
神经病学 | 364篇 |
特种医学 | 44篇 |
外科学 | 163篇 |
综合类 | 218篇 |
预防医学 | 88篇 |
眼科学 | 46篇 |
药学 | 161篇 |
2篇 | |
中国医学 | 182篇 |
肿瘤学 | 18篇 |
出版年
2023年 | 15篇 |
2022年 | 40篇 |
2021年 | 50篇 |
2020年 | 57篇 |
2019年 | 47篇 |
2018年 | 48篇 |
2017年 | 57篇 |
2016年 | 61篇 |
2015年 | 49篇 |
2014年 | 164篇 |
2013年 | 116篇 |
2012年 | 109篇 |
2011年 | 130篇 |
2010年 | 85篇 |
2009年 | 59篇 |
2008年 | 50篇 |
2007年 | 69篇 |
2006年 | 54篇 |
2005年 | 40篇 |
2004年 | 51篇 |
2003年 | 32篇 |
2002年 | 30篇 |
2001年 | 44篇 |
2000年 | 25篇 |
1999年 | 26篇 |
1998年 | 29篇 |
1997年 | 17篇 |
1996年 | 25篇 |
1995年 | 19篇 |
1994年 | 17篇 |
1993年 | 37篇 |
1992年 | 17篇 |
1991年 | 11篇 |
1990年 | 19篇 |
1989年 | 17篇 |
1988年 | 17篇 |
1987年 | 16篇 |
1986年 | 12篇 |
1985年 | 13篇 |
1984年 | 13篇 |
1983年 | 5篇 |
1982年 | 10篇 |
1981年 | 9篇 |
1980年 | 10篇 |
1979年 | 8篇 |
1978年 | 10篇 |
1977年 | 12篇 |
1976年 | 6篇 |
1975年 | 7篇 |
1972年 | 6篇 |
排序方式: 共有1887条查询结果,搜索用时 15 毫秒
1.
目的 运用CT区分脾脏血管性病变与淋巴瘤。方法 回顾性分析20例经手术、穿刺病理学检查证实的脾脏病变的发病年龄、性别、脾脏指数、病变大小、数目、有无液化、钙化、强化幅度、强化方式等特征,并进行统计学分析。结果 20例脾脏病变中,11例血管性病变(6例海绵状血管瘤,3例窦岸细胞血管瘤,2例硬化性血管瘤样结节性转化),9例淋巴瘤;两组间发病年龄、病变大小、数目、有无液化、钙化等差异无统计学意义;两组间脾脏指数、动脉期强化幅度差异具有统计学意义(P<0.05)。5例海绵状血管瘤呈不均匀性强化,1例呈渐进性填充式强化,2例窦岸细胞血管瘤呈“雀斑征”,1例硬化性血管瘤样结节性转化呈“辐轮征”;9例淋巴瘤实质部分均呈均匀、轻中度强化。结论 脾脏血管性病变与淋巴瘤CT表现不同,CT有助于明确诊断。 相似文献
2.
《Clinical neurophysiology》2020,131(5):1087-1098
ObjectiveFunctional connectivity networks (FCNs) based on interictal electroencephalography (EEG) can identify pathological brain networks associated with epilepsy. FCNs are altered by interictal epileptiform discharges (IEDs), but it is unknown whether this is due to the morphology of the IED or the underlying pathological activity. Therefore, we characterized the impact of IEDs on the FCN through simulations and EEG analysis.MethodsWe introduced simulated IEDs to sleep EEG recordings of eight healthy controls and analyzed the effect of IED amplitude and rate on the FCN. We then generated FCNs based on epochs with and without IEDs and compared them to the analogous FCNs from eight subjects with infantile spasms (IS), based on 1340 visually marked IEDs. Differences in network structure and strength were assessed.ResultsIEDs in IS subjects caused increased connectivity strength but no change in network structure. In controls, simulated IEDs with physiological amplitudes and rates did not alter network strength or structure.ConclusionsIncreases in connectivity strength in IS subjects are not artifacts caused by the interictal spike waveform and may be related to the underlying pathophysiology of IS.SignificanceDynamic changes in EEG-based FCNs during IEDs may be valuable for identification of pathological networks associated with epilepsy. 相似文献
3.
Fas/FasL在各阶段婴幼儿血管瘤中的表达及意义 总被引:15,自引:0,他引:15
目的 检测Fas/FasL在各阶段婴幼儿血管瘤组织中的表达,探讨Fas/FasL在婴幼儿血管瘤细胞凋亡中的作用。方法 应用EnVision法免疫组化染色和RT-PCR检测Fas/FasL蛋白及mRNA在各阶段血管瘤组织中的表达。结果 ①增生早期和增生中期,部分血管瘤细胞表达Fas;增生晚期,阳性细胞明显增多,Fas mRNA表达最强;消退早期,仍有少量微血管内皮细胞表达Fas,之后Fas表达迅速减弱。②最早期细胞团中没有FasL(+)细胞;增生中期,血管瘤组织中出现少量FasL(+)细胞;增生晚期FasL(+)细胞显著增多,FasL mRNA表达最强;消退早期之后,FasL(+)细胞迅速减少以至消失。结论 Fas/FasL与婴幼儿血管瘤演变过程有密切联系,Fas/FasL介导的血管瘤细胞凋亡可能是婴幼儿血管瘤自行消退的重要原因。 相似文献
4.
Nephrotic syndrome in a mother and her infant: relationship with cytomegalovirus infection 总被引:1,自引:0,他引:1
Marisa Giani Alberto Edefonti Beatrice Damiani Giuseppina Marra Daniela Colombo Giovanni Banfi Emilio Rivolta Erich H. Strøm Michael Mihatsch 《Pediatric nephrology (Berlin, Germany)》1996,10(1):73-75
This case report describes infantile nephrotic syndrome (NS) in a baby girl with a clinically severe cytomegalovirus (CMV) infection. Culture of the baby's urine was positive for CMV and IgM anti-CMV antibodies were detected. After an unsuccessful course of corticosteroids, gancyclovir treatment was started and a remission of cutaneous, pulmonary, and renal symptoms was achieved. As the mother also developed NS at the end of pregnancy, a common etiology could be postulated, although there were no signs of recent CMV infection in the mother, only anti-CMV IgG. The relationship between CMV infection and glomerular disease is still unclear: NS may represent another manifestation of CMV disease. 相似文献
5.
Various neocortical areas from four females aged 16–24 years with Rett syndrome (RS) were investigated and compared with
brains of therapy-resistant partial epilepsy (TRPE) patients (18–25 years), infantile autism (IA), and control brains (24
and 58 years). The cytoarchitecture of area 10 (frontal), area 21 (temporal), area 4 (primary motor cortex), and area 17 (primary
visual cortex) was studied by the combined Klüver-Barrera (luxol fast blue and cresyl violet) standard procedure. Autofluorescence
of lipofuscin, immunofluorescence of synaptic vesicle proteins [synaptophysin (p38)] and lectin-stained (Wisteria floribunda agglutinin) perineuronal nets (PNs) were studied in the cortices using dual-channel confocal laser scanning microscopy. The
brains of RS females show various types of morphological/cytoarchitectonical abnormalities of single pyramidal neurons in
layers II–III, and V–VII of different cortical areas. The abnormalities include mild losses of pyramidal neurons, more pronounced
in layers II and III than in layers V and VII, and more evident in frontal and temporal areas than in the visual cortex. Microdysgenesis,
including abnormalities due to neuronal migration disorders, was not found in RS, in contrast to the observations in TRPE
patients, strongly indicating that RS is not a neuronal migration disorder. Lipofuscin distribution was normal but amounts
were lower in RS cases than in control and TRPE brains. PNs were less expressed in cortices of the IA case, but were clearly
overexpressed in the motor cortex of RS. Quantitative analysis of p38 showed a decrease in the area occupied by p38 immunoreactivity
by 20–40% in RS compared with controls. It is concluded that RS could best be explained by a postnatal synaptogenic developmental
deficiency; the basic defect, however, is still completely unknown.
Received: 26 February 1996 / Revised, accepted: 11 July 1996 相似文献
6.
Tracy A. Glauser 《Epilepsia》2004,45(S5):23-26
Summary: As patients with catastrophic epilepsies move from childhood to adulthood, evolving and innovative therapeutic regimens are often required. However, the goal of providing the best quality of life while minimizing both seizures and side effects remains the same. Clinicians can develop appropriate care plans by being aware of patients' changing needs. Clinical symptoms of the catastrophic epilepsies may change over time; by understanding the natural history of a patient's condition, clinicians can help ease the transition from childhood to adulthood. Additionally, as children with catastrophic epilepsies become adults, medical issues (e.g., medication side effects, tolerance, and dependence) and nonmedical issues (e.g., guardian/caretaker issue, group home applications, and respite care options) must be considered when developing strategies for patient care. Regular assessment of patients, the development of emergency plans, and maintenance of consistency in the delivery of care are also important issues to consider. Finally, a multidisciplinary care plan that incorporates resources from health-care practitioners, social service professionals, and community agencies can be valuable in optimizing treatment for patients with catastrophic epilepsies. 相似文献
7.
M. F. Gagnadoux J. L. Bacri M. Broyer R. Habib 《Pediatric nephrology (Berlin, Germany)》1989,3(1):50-55
Over a 15-year period we observed seven children (four girls, three boys) who presented within the first months of life with severe renal failure and acidosis, associated with hypertension in five patients and polyuria in four. In addition, one patient had a severe cholestatic liver disease. In two families, a similarly affected sibling had died previously. Four patients were referred with the clinical diagnosis of polycystic kidney disease because of moderate enlargement of kidneys, but renal imaging (intravenous pyelography and ultrasonography) did not confirm this diagnosis. A renal biopsy, performed in all patients, showed similar features characterized by a diffuse chronic tubulo-interstitial nephritis (TIN) and particularly by the presence of microcystic dilatation of proximal tubules and Bowman's space. Liver pathology was normal in two patients, including one with hepatomegaly. However, in the patient with cholestasis there was inflammatory portal fibrosis with mild duct proliferation. Progression of the renal disease was extremely rapid and all patients reached end-stage renal failure (ESRF) before the age of 2 years (11–22 months). Two children had successful renal transplants. Although this chronic TIN shares some features with nephronophthisis, we suggest that it represents a distinct entity both on clinical and morphological grounds. The specific clinical features of this disease are its early onset and rapid progression to ESRF. Pathologically, it differs from nephronophthisis by the absence of medullary cysts and thickened tubular basement membranes and by the presence of cortical microcysts. 相似文献
8.
Dr. S. J. Vinnicombe B.Sc. M.R.C.P. F.R.C.R. C. M. Hall F.R.C.R. 《Skeletal radiology》1994,23(5):337-341
Two cases of infantile fibrosarcoma are described. This rare childhood malignancy of mesodermal origin usually affects the
lower limbs, as it did in both of our cases. Previously, the only treatment option available involved some form of radical
and often mutilating surgery. More recently, combination chemotherapy has given good results, with the effect that various
imaging modalities have become important in assessing both the initial extent of disease and the response to treatment. Computed
tomography has the advantage of demonstrating the amount of osseous involvement, but at the expense of a considerable dose
of ionizing radiation. On the other hand, magnetic resonance imaging, with its multiplanar capacity, gives superior demonstration
of breaching of tissue planes, which has important implications for planning of surgery. However, as in other soft tissue
tumours, changes in signal characteristics with treatment have proved less specific than was originally anticipated. 相似文献
9.
Anthony M. Norcia Russell D. Hamer Arthur Jampolsky Deborah Orel-Bixler 《Vision research》1995,35(23-24)
Monocular oscillatory-motion visual evoked potentials (VEPs) were measured in prospective and retrospective groups of infantile esotropia patients who had been aligned surgically at different ages. A nasalward-temporal response bias that is present prior to surgery was reduced below pre-surgery levels in the prospective group. Patients in the retrospective group who had been aligned before 2 yr of age showed lower levels of response asymmetry than those who were aligned after age 2. The data imply that binocular motion processing mechanisms in infantile esotropia patients are capable of some degree of recovery, and that this plasticity is restricted to a critical period of visual development. 相似文献
10.
婴幼儿血管瘤病理结构变化与临床演变过程的联系 总被引:1,自引:0,他引:1
目的探讨婴幼儿血管瘤患者临床演变过程和病理结构变化的内在联系。方法选取52例婴幼儿血管瘤标本,年龄2个月至11岁。采用HE染色观察各阶段血管瘤的病理特点,使用图像分析系统分析血管瘤组织中的细胞总数量、微血管总数量和总面积。结果按患儿出生后时间:1~6个月,血管瘤中细胞增殖速度快、排列紧密,微血管数量迅速增加;7~12个月,血管瘤中细胞数量迅速减少,微血管数量减少,但总面积继续扩大;1~3岁,大部分血管瘤组织呈微血管团样,微血管面积最大;3~5岁,微血管数量和总面积均迅速减少;5岁之后,大部分血管瘤消退完成,被纤维脂肪组织代替。结论婴幼儿血管瘤患者临床演变过程和病理结构变化有密切联系,病理结构变化主导临床演变过程。 相似文献