全文获取类型
收费全文 | 8006篇 |
免费 | 514篇 |
国内免费 | 50篇 |
专业分类
耳鼻咽喉 | 120篇 |
儿科学 | 171篇 |
妇产科学 | 127篇 |
基础医学 | 971篇 |
口腔科学 | 270篇 |
临床医学 | 679篇 |
内科学 | 1685篇 |
皮肤病学 | 165篇 |
神经病学 | 516篇 |
特种医学 | 315篇 |
外国民族医学 | 2篇 |
外科学 | 1252篇 |
综合类 | 136篇 |
一般理论 | 5篇 |
预防医学 | 548篇 |
眼科学 | 362篇 |
药学 | 731篇 |
中国医学 | 73篇 |
肿瘤学 | 442篇 |
出版年
2024年 | 9篇 |
2023年 | 100篇 |
2022年 | 203篇 |
2021年 | 378篇 |
2020年 | 249篇 |
2019年 | 315篇 |
2018年 | 403篇 |
2017年 | 270篇 |
2016年 | 329篇 |
2015年 | 319篇 |
2014年 | 469篇 |
2013年 | 571篇 |
2012年 | 800篇 |
2011年 | 793篇 |
2010年 | 461篇 |
2009年 | 324篇 |
2008年 | 513篇 |
2007年 | 474篇 |
2006年 | 363篇 |
2005年 | 297篇 |
2004年 | 224篇 |
2003年 | 232篇 |
2002年 | 176篇 |
2001年 | 34篇 |
2000年 | 24篇 |
1999年 | 34篇 |
1998年 | 24篇 |
1997年 | 13篇 |
1996年 | 17篇 |
1995年 | 13篇 |
1994年 | 12篇 |
1993年 | 12篇 |
1992年 | 4篇 |
1991年 | 9篇 |
1990年 | 4篇 |
1989年 | 11篇 |
1988年 | 11篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1982年 | 8篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1978年 | 7篇 |
1977年 | 5篇 |
1976年 | 8篇 |
1975年 | 9篇 |
1974年 | 6篇 |
排序方式: 共有8570条查询结果,搜索用时 15 毫秒
31.
Endometrial receptivity and implantation are important topics in reproductive sciences. No evidence was found to support sperm involvement in endometrial receptivity and its associated factors. This study aimed to explore the effect of the normal human spermatozoa–endometrium cell interaction in regulating genes in the endometrial receptivity pathway. Semen samples were collected from a healthy and fertile man; then, they were incubated with endometrial cells for 24 hr and considered as the sperm group. A group was cultured without spermatozoa and considered as a control group. About 24 hr later, cells were collected from the bottom of the culture dish. The expressions of the VEGF, FGF2, HBEGF, LIFR, EGF, LIF, MUC1, HOXA10, CSF and PGR genes were evaluated in the two groups. Statistical analysis was performed using an independent sample test. Compared with the control group, in the sperm group, the mRNA levels of PGR (p = .0451), VEGF (p = .0101), HBEGF (p = .0163), EFG (p = .0339), FGF2 (p = .012), LIF (p = .0324), LIFR (p = .0321) and HOXA10 (p = .0098) were significantly upregulated. The results showed that there is a need for the interaction between spermatozoa and endometrium for implantation and can be used for preparing uterine in in vitro fertilisation cycles. 相似文献
32.
33.
Hamed Nikoupour MD Peyman Arasteh MD MPH Alireza Shamsaeefar MD Fardin Ghanbari MD Arash Boorboor MD Ali Mosa Jafar Almayali MD Mojtaba Shafiekhani PharmD Ph.D Pirouz Samidoust MD Reza Shahriarirad MD Alireza Shojazadeh MD Keivan Ranjbar MD Mohammad Hasan Darabi MD Sina Tangestanipour MD Seyed Morteza Hosseini MD Leila Zahiri MD Saman Nikeghbalian MD 《JPEN. Journal of parenteral and enteral nutrition》2022,46(4):946-957
34.
Aileen Azari-Yaam Mohammad Reza Abdolsalehi Mohammad Vasei Moeinadin Safavi Mehrzad Mehdizadeh 《Head and neck pathology》2021,15(1):352
Rosai–Dorfman disease (RDD) is a rare and self-limiting disease process that presents most commonly in young patients as massive, painless, cervical lymphadenopathy. Extranodal involvement may also occur. Histopathologic evaluation is the main diagnostic modality. We report an unusual presentation of RDD with cervical lymphadenopathy and an incidentally discovered sinonasal mass, clinically worrisome for malignancy. We emphasize that a high index of clinical suspicion is critical for accurate diagnosis of RDD. Clinicians and pathologists should consider RDD in a differential diagnosis of cervical lymphadenopathy, especially in young patients. 相似文献
35.
36.
Ghanbari Jahromi Mohadeseh Goudarzi Reza Amini Saeed Anbari Zohreh Amiresmaili Mohammadreza 《Zeitschrift fur Gesundheitswissenschaften》2021,29(3):625-631
Journal of Public Health - Iranian New Year, with long consecutive holidays, although it is celebrated and enjoyed, might influence the quality of services provided by hospitals. The present study... 相似文献
37.
Arezo Nahavandi Ahmad Reza Dehpour Ali Reza Mani Homayoun Homayounfar Ali Abdoli 《European journal of pharmacology》1999,370(3):1170
In this study the effect of nitric oxide (NO) synthesis inhibition on ethanol-induced gastric damage was evaluated in bile duct-ligated, sham-operated and unoperated rats. The animals were injected intraperitoneally with saline,
-arginine (200 mg/kg) or NG-nitro-
-arginine methylester (
-NAME) in doses of 5, 15 and 30 mg/kg, 30 min before ethanol administration. The animals were killed 1 h after ethanol administration and their stomachs were removed for measurement of gastric mucosal damage. The results showed that
-NAME significantly enhanced the development of gastric mucosal lesions in sham-operated and unoperated rats, while in bile duct-ligated animals,
-NAME decreased and
-arginine enhanced the potentiation of ethanol-induced gastric mucosal damage. The plasma level of nitrite and nitrate was also measured and was significantly higher in bile duct-ligated rats than in control groups. The results suggest that inhibition of NO synthase with
-NAME has different effects on ethanol-induced gastric damage in cholestatic groups and in normal rats and that these effects can be explained by overproduction of NO in bile duct-ligated animals. 相似文献
38.
Novelty and Familiarity Activations in PET Studies of Memory Encoding and Retrieval 总被引:16,自引:3,他引:13
Tulving Endel; Markowitsch Hans J.; Craik Fergus I. M.; Habib Reza; Houle Sylvain 《Cerebral cortex (New York, N.Y. : 1991)》1996,6(1):71-79
Nine young right-handed men viewed colored pictures of people,scenes, and landscapes. Then, 24 hr later while undergoing PETscanning, they viewed previously studied (OLD) pictures in onetype of scan, and previously not seen (NEW) pictures in another.The OLD-NEW subtraction of PET images indicates familiarity,and the NEW-OLD indicates novelty. Familiarity activations,signalling aspects of retrieval, were observed in the left andright frontal areas, and posterior regions bilaterally. Noveltyactivations were in the right limbic regions, and bilaterallyin temporal and parietal regions, including area 37. These latteractivations were located similarly to novelty activations inprevious PET studies using visual words and auditory sentences,suggesting the existence of brain regions specializing in transmodalnovelty assessment The effects of novelty are seen both be haviorallyand in replicable patterns of cortical and subcortical activation.We propose a "novelty/encoding hypothesis": (1) novelty assessmentrepresents an early stage of long-term memory encoding; (2)elaborate, meaning-based encoding processes operate on the incoming information to the extent of its novelty, and therefore(3) the probability of long-term storage of information vanesdirectly with the novelty of the information. 相似文献
39.
Anne L Clark Ann M Gillenwater Thomas G Collier Reza Alizadeh-Naderi Adel K El-Naggar Rebecca R Richards-Kortum 《Clinical cancer research》2003,9(13):4714-4721
PURPOSE: The goal of this study was to characterize features of normal and neoplastic oral mucosa using reflectance confocal microscopy. EXPERIMENTAL DESIGN: Oral cavity biopsies were acquired from 17 patients at the Head and Neck Clinic of The University of Texas M. D. Anderson Cancer Center who were undergoing surgery for squamous cell carcinoma within the oral cavity. Reflectance confocal images were obtained at multiple image plane depths from biopsies within 6 h of excision. After imaging, biopsies were fixed in 10% formalin and submitted for routine histological examination. Reflectance confocal images were compared with histological images from the same sample to determine which tissue features contribute to image contrast and can be potentially imaged using in vivo confocal microscopy. RESULTS: Confocal images were successfully acquired from 15 biopsy pairs from 17 patients. Depth-related changes in cell diameter and nuclear density were observed at multiple anatomical sites within the oral cavity. In squamous cell carcinomas, densely packed, pleomorphic tumor nuclei could be visualized with distinct differences in nuclear density and morphology distinguishable between confocal images of neoplastic and nonneoplastic oral cavity. Other features of noncancerous and cancerous oral tissue that could be identified in the confocal images included areas of inflammation, fibrosis, muscle fibers, and salivary glands. CONCLUSIONS: Our results support the potential for this tool to play a significant role in the clinical evaluation of oral lesions, real-time identification of tumor margins, and monitoring of response to therapeutic treatment. 相似文献
40.
Avi Shupak Reza Tabari Douglas J. Swarts Charles D. Bluestone William J. Doyle 《The Laryngoscope》1997,107(10):1409-1413
Middle ear negative pressure and effusions, decreased middle ear compliance, and abnormal tympanometry results have been described after diving on oxygen. Middle ear gas hyperoxia has been shown to down-regulate the eustachian tube ventilatory function (ETVF). The purpose of the present study was to investigate to what extent systemic hyperoxia in the face of air-equivalent middle ear gas composition might interfere with the ETVF. ETVF was investigated in four young adult female cynomolgus monkeys by the forced-response and inflation-deflation tests using air while the animals breathed either room air or 100% normobaric oxygen. Higher opening, closing, and steady-state pressures were observed under systemic hyperoxia. The percentage of the applied pressure equalized, and the maximal pressure change on a single swallow in the deflation test were both lower under hyperoxic conditions. The results show that systemic hyperoxia might impair ETVF. This observation adds to our understanding of the pathophysiology of middle ear dysfunction observed after diving on oxygen. 相似文献