全文获取类型
收费全文 | 2727篇 |
免费 | 127篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 79篇 |
儿科学 | 181篇 |
妇产科学 | 169篇 |
基础医学 | 178篇 |
口腔科学 | 161篇 |
临床医学 | 184篇 |
内科学 | 477篇 |
皮肤病学 | 58篇 |
神经病学 | 256篇 |
特种医学 | 89篇 |
外科学 | 741篇 |
综合类 | 25篇 |
一般理论 | 1篇 |
预防医学 | 46篇 |
眼科学 | 63篇 |
药学 | 81篇 |
肿瘤学 | 89篇 |
出版年
2024年 | 2篇 |
2023年 | 27篇 |
2022年 | 50篇 |
2021年 | 108篇 |
2020年 | 78篇 |
2019年 | 89篇 |
2018年 | 106篇 |
2017年 | 97篇 |
2016年 | 126篇 |
2015年 | 146篇 |
2014年 | 142篇 |
2013年 | 169篇 |
2012年 | 230篇 |
2011年 | 225篇 |
2010年 | 121篇 |
2009年 | 109篇 |
2008年 | 169篇 |
2007年 | 186篇 |
2006年 | 167篇 |
2005年 | 132篇 |
2004年 | 99篇 |
2003年 | 66篇 |
2002年 | 83篇 |
2001年 | 25篇 |
2000年 | 31篇 |
1999年 | 20篇 |
1998年 | 8篇 |
1997年 | 10篇 |
1996年 | 6篇 |
1995年 | 14篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1992年 | 8篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 2篇 |
排序方式: 共有2878条查询结果,搜索用时 187 毫秒
941.
Akgul Akpinarli Dicle Guc Omer Kalayci Emre Yigitbas Alev Ozon 《The Journal of asthma》2002,39(2):159-165
Both atopy and asthma are claimed to be associated with a Th-2 cytokine pattern. We sought to determine the contribution of atopy and asthma to the observed Th-2/Th-1 imbalance in these conditions. Of 60 children aged 6-16 years that were included in the study, 13 were nonatopic nonasthmatic, 15 atopic nonasthmatic, 14 nonatopic asthmatic, and 18 atopic asthmatic. Atopic children had positive skin prick tests to grass pollens only. All children were studied after an asymptomatic and drug-free period of at least three months. Total IgE was measured in serum. Peripheral blood mononuclear cells were cultured and stimulated in vitro with phytohemagglutinin and interferongamma (IFN-gamma) and interleukin-4 (IL-4) measured in the supernatants. Total IgE was significantly higher in atopic asthmatics compared to nonatopic asthmatics (p = 0.004), and nonatopic nonasthmatics (p = 0.001), but was not different from atopic nonasthmatics (p >0.05). On the other hand, IL-4 was significantly elevated in atopic asthmatics and in nonatopic asthmatics compared to nonatopic nonasthmatics (p = 0.037 and p = 0.009, respectively). Although atopic asthmatics had lower IFN-gamma values than nonatopic asthmatics, the difference did not reach statistical significance. No correlation was detected between any two parameters. Our results suggest that both atopy and asthma contribute to the increased levels of IL-4 and that, whereas nonatopic asthma is associated with increases in both IL-4 and IFN-gamma release by mononuclear cells, only atopic asthma is characterized by a Th-2 type cytokine dominance. 相似文献
942.
Mathias P. G. Bostrom Joseph M. Lane Wayne S. Berberian Albert A. E. Missri Emre Tomin Andrew Weiland Stephen B. Doty David Glaser Vicki M. Rosen 《Journal of orthopaedic research》1995,13(3):357-367
Recently, it has become increasingly evident that fracture healing involves a complex interaction of many local and systemic regulatory factors. The roles of some of these growth factors have been described; however, little is understood about the presence of the bone morphogenetic proteins in fracture repair, despite the fact that they are the most potent osteoinductive proteins known. This study defines and characterizes the physiologic presence, localization, and chronology of the bone morphogenetic proteins in fracture healing with an established rat fracture healing model. With use of a recently developed monoclonal antibody against bone morphogenetic proteins 2 and 4 developed with standard avidin-biotin complex/immunoperoxidase protocols, frozen undecalcified fracture calluses were analyzed semiquantitatively for the percentage of various types of fracture cells staining positively. During the early stages of fracture healing, only a minimum number of primitive cells stained positively in the fracture callus. As the process of endochondral ossification proceeded, the presence of bone morphogenetic proteins 2 and 4 increased dramatically, especially in the primitive mesenchymal and chondrocytic cells. While the cartilaginous component of the callus matured with a concomitant decrease in the number of primitive cells, there was a concomitant decrease in both the intensity and the number of positively staining cells. As osteoblasts started to lay down woven bone on the chondroid matrix, these osteoblastic cells exhibited strong positive staining. The intensity of this staining decreased, however, as lamellar bone replaced the primitive woven bone. A similar observation was noted for the areas of the callus undergoing intramembranous ossification. Initially, within several days after the fracture, periosteal cells and osteoblasts exhibited intense staining for bone morphogenetic proteins 2 and 4. As the woven bone was replaced with mature lamellar bone, this staining decreased. These data, and the awareness of the strong osteoinductive capacities of bone morphogenetic protein, suggest that bone morphogenetic proteins 2 and 4 are important regulators of cell differentiation during fracture repair. 相似文献
943.
Effects of the novel competitiveN-methyl-d-aspartate (NMDA)-receptor antagonist SDZ EAA 494 were investigated on memory and attention in humans. SDZ EAA 494 was administered either as single doses at a dose range of 1–50 mg, or as multiple doses over the course of 1 week at doses of 25 mg once or twice daily. Selected cognitive functions were assessed at baseline, 2 and 4 h after single dose administration, and at baseline, 2, 4 and 8 h on days 1 and 7 of multiple dose administration. The assessments included simple and complex reaction time tests to assess attention, and verbal, non-verbal and spatial memory tests with immediate and late recall. Verbal and non-verbal memory test performance was significantly impaired at a dose level of 50 mg after single administration, and of 25 mg twice daily after multiple administration, without concomitant significant impairment of reaction time. Spatial memory test performance was not significantly affected. The maximum effect occurred 2 h postmedication and was more pronounced after repeated administration. These results suggest that the inhibition of NMDA-receptors in humans may impair memory processes. 相似文献
944.
Emre Akkus 《Current Sexual Health Reports》2005,2(1):17-20
Penile fracture (PF) is an uncommon injury defined as the rupture of the tunica albuginea and corpus cavernosum of the penis,
usually resulting from direct blunt trauma to the erect penis during sexual intercourse or masturbation. PF is one of the
few urologic emergencies. This article reviews the status, contemporary management, and the controversies of the diagnostic
approaches and therapeutic modalities of penile fractures. It is usually diagnosed only clinically with the history of the
patient, inspection, and physical examination. However, additional imaging procedures such as cavernosography, ultrasonography,
magnetic resonance imaging, and retrograde ureterography may also be indicated whenever the diagnosis or the extent of the
severity and location of the rupture is not clear, and/or when an accompanying urethral injury is suspected. Although the
diagnosis of PF is usually easily recognized, optimal therapy remains controversial. The most widely accepted approach for
the treatment of PF is early surgical treatment, but some investigators still advocate nonoperative conservative management. 相似文献
945.
Murat Emre 《Journal of neurology》1992,239(4):228-230
Summary Palatal myoclonus is thought to occur after damage to certain brain-stem structures, and with a delay following the causative lesion. A case of palatal myoclonus, probably of epileptic nature, is described. 相似文献
946.
Richard J. Caselli Anthony J. Windebank Ronald C. Petersen Takashi Komori Joseph E. Parisi Haruo Okazaki Emre Kokmen Rita Iverson Robert P. Dinapoli Neill R. Graff-Radford Steven D. Stein 《Annals of neurology》1993,33(2):200-207
Articulatory and language impairment heralded rapidly progressive motor neuron disease in 7 patients aged 54 to 77 years. One patient had a family history of a similar disorder. Severe nonfluent aphasia developed in all 7 patients and 4 were anarthric within a year. Other cognitive domains were impaired, yet 2 patients lived alone until 1 month before their deaths. Four died within 2 years. Abnormalities were found on electromyography, computed tomography, magnetic resonance imaging, single-photon emission computed tomography, and electroencephalography. Neuropathological examination in 3 patients showed bilateral hemispheric atrophy with neuronal loss and gliosis predominantly of superficial cortical layers. Pigmented and hypoglossal nuclei were relatively preserved. At all spinal levels there was degeneration of corticospinal tracts and loss of anterior horn cells with gliosis. Rapidly progressive aphasic dementia and motor neuron disease are a distinctive clinical entity whose nosology is poorly understood. 相似文献
947.
Mete Iseri Emre Ustundag Berna Yayla Ahmet Kaur 《Otolaryngology--head and neck surgery》2006,135(1):36-39
OBJECTIVE: This study was undertaken to evaluate the use of the Medpor (Porex Surgical, College Park, GA) implant in laryngeal reconstruction and to discuss potential indications of this material in head and neck surgeries. METHOD: Twelve rabbits were used in this particular study. Laryngoplasties were performed by extracting 5 x 10-mm thyroid cartilage and replacing it with Medpor implant. Animals were sacrificed in the 1st, 2nd, and 4th weeks and 2, 6, and 9 months after implantation. The degree of fibrous capsule formation, histiocytic reaction, foreign body giant cell reaction, lymphocytic and neutrophilic reactions, vocal fold changes, and hyaline cartilage formation in the implant bed were evaluated. RESULTS: Fibrous capsule was formed around the implant in 2 weeks. Four weeks after the implantation cellular reaction in the implant bed decreased significantly. Foreign body giant cell reaction was detected only the first 2 weeks after the implantation. CONCLUSION: According to the results of this study, the Medpor implant can be safely used in laryngeal reconstruction. 相似文献
948.
I. Rozanes B. Acunaş A. Emre A. Alper I. Sayi Ö. Minareci K. Acarli H. Hazar O. Ariogul 《European radiology》1995,5(3):259-263
The purpose of this study was to assess the usefulness of a new staging scheme for alveolar echinoccocosis un of the liver. A total of 28 patients with hepatic alveolar echinococcosis underwent CT examinations and were staged according to the proposed staging scheme (stage 1: lesion measuring less than 3 cm in diameter; stage 2: lesion greater than 3 cm, confined to less than three hepatic segments; stage 3 a: lesion with invasion of more than three hepatic segments; stage 3 b: invasion of liver hilum or suprahepatic vena cava; stage 4: invasion of surrounding organs and/or distant metastasis). Of the patients 16 underwent laparotomy, and results of the radiologic staging were correlated with surgical data. The CT findings correlated well with surgical findings. Patients were followed-up for a period of 6 months to 7 years. We concluded that the proposed staging scheme seemed to be useful for the therapeutic planning of patients with alveolar echinococcosis of the liver.
Correspondence to: I. Rozanes 相似文献
949.
An approximation technique is developed for the steady-state solution of the time-varying matrix Riccati equation. We show how the Newton-type algorithm of Kleinman, developed for computing the steady solution to the algebraic Riccati equation for time-invariant systems, can be extended for time-varying linear systems. The time-varying case is considerably more involved than the time-invariant one. Consider a linear time-varying system x (t) = F (t) x (t) + G (t) u (t). If ( F , G ) is uniformly completely controllable, we show how one can construct a recursive sequence of matrix functions (using linear techniques) which converge to the steady-state solution of the associated time-varying matrix Riccati equation (a non-linear object). At each successive state, the next approximation is in terms of the steady-state solution to a linear Lyapunov differential equation (which is the extension of the algebraic Lyapunov equations used by Kleinman) for which an explicit expression exists. This provides an approximation technique for obtaining infinite-time, linear-quadratic, optimal controllers and steady-state Kalman—Bucy filters for time-varying systems using purely linear techniques. Thus, we provide new types of suboptimal stabilizing feedback laws for linear time-varying systems. 相似文献
950.
Mehmet Kürk?ü I Attila Oz Fatih K?ksal M Emre Benlidayi Aylin Güne?li 《Journal of oral and maxillofacial surgery》2005,63(11):1593-1598
PURPOSE: The purposes of the study presented are to identify the microbial content of the collected bone debris and to determine the antibacterial efficiency of chlorhexidine mouth rinse in reducing the microbial content of the collected bone debris. PATIENTS AND METHODS: Twenty-five patients who had asymptomatic fully impacted mandibular third molars bilaterally underwent surgical removal for prophylactic and orthodontic considerations. Immediately before surgery all patients rinsed with 10 mL of their assigned solution (chlorhexidine or sterile saline) for 2 minutes. Before surgical removal of the teeth, bone debris was collected with a stringent aspiration protocol from the ramus by bone filter. The microbial content of the bone debris was assessed and the bacterial levels between the 2 groups were compared statistically. RESULTS: All samples from both groups (chlorhexidine or sterile saline) yielded viable microorganisms. There was no significant difference between the mean/median colony-forming units (CFU)/g values of both group samples, for aerobes (Streptococcus salivarius) and anaerobes (Bacteroides, Peptococcus, Peptostreptococcus, and Veillonella species). With regard to total microorganisms, the mean CFU/g derived from the chlorhexidine group samples were 1.5 x 10(8) CFU/g per bone sample compared with 1.5 x 10(9) CFU/g for the sterile saline control group (P < .05). CONCLUSION: Although chlorhexidine rinsing immediately before surgery reduced the levels of total microorganisms when compared with stringent aspiration protocol alone, it has not been found effective on aerobic Streptococcus salivarius and, importantly, on anaerobes. The reduced bacterial levels may still carry high infectious risk and may lead to failure in autogenous grafting procedures in oral surgery. 相似文献