全文获取类型
收费全文 | 12353篇 |
免费 | 804篇 |
国内免费 | 71篇 |
专业分类
耳鼻咽喉 | 236篇 |
儿科学 | 276篇 |
妇产科学 | 231篇 |
基础医学 | 1635篇 |
口腔科学 | 405篇 |
临床医学 | 1074篇 |
内科学 | 2539篇 |
皮肤病学 | 198篇 |
神经病学 | 776篇 |
特种医学 | 464篇 |
外国民族医学 | 4篇 |
外科学 | 1937篇 |
综合类 | 226篇 |
一般理论 | 8篇 |
预防医学 | 814篇 |
眼科学 | 472篇 |
药学 | 1086篇 |
中国医学 | 106篇 |
肿瘤学 | 741篇 |
出版年
2024年 | 14篇 |
2023年 | 148篇 |
2022年 | 326篇 |
2021年 | 572篇 |
2020年 | 372篇 |
2019年 | 475篇 |
2018年 | 597篇 |
2017年 | 393篇 |
2016年 | 466篇 |
2015年 | 478篇 |
2014年 | 683篇 |
2013年 | 828篇 |
2012年 | 1216篇 |
2011年 | 1169篇 |
2010年 | 656篇 |
2009年 | 458篇 |
2008年 | 736篇 |
2007年 | 699篇 |
2006年 | 587篇 |
2005年 | 480篇 |
2004年 | 382篇 |
2003年 | 393篇 |
2002年 | 309篇 |
2001年 | 93篇 |
2000年 | 80篇 |
1999年 | 73篇 |
1998年 | 59篇 |
1997年 | 34篇 |
1996年 | 37篇 |
1995年 | 23篇 |
1994年 | 30篇 |
1993年 | 27篇 |
1992年 | 26篇 |
1991年 | 31篇 |
1990年 | 18篇 |
1989年 | 26篇 |
1988年 | 31篇 |
1987年 | 24篇 |
1986年 | 9篇 |
1985年 | 18篇 |
1984年 | 12篇 |
1982年 | 10篇 |
1980年 | 10篇 |
1979年 | 9篇 |
1978年 | 12篇 |
1977年 | 10篇 |
1976年 | 10篇 |
1975年 | 12篇 |
1974年 | 14篇 |
1973年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
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
72.
73.
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
74.
Dlugosz LJ Hocter WJ Kaiser KS Knoke JD Heller JM Hamid NA Reed RJ Kendler KS Gray GC 《Journal of clinical epidemiology》1999,52(12):90-1278
Effects of Persian Gulf War (August 2, 1990–July 31, 1991) and Gulf War occupation on post-War hospitalization risk were evaluated through Cox proportional hazards modeling. Active-duty men (n = 1,775,236) and women (n = 209,760) in the Army, Air Force, Navy, and Marine Corps had 30,539 initial postwar hospitalizations for mental disorders between June 1, 1991 and September 30, 1993. Principal diagnoses in the Defense Manpower Data Center hospitalization database were grouped into 10 categories of ICD-9-CM codes. Gulf War service was associated with significantly greater risk for acute reactions to stress and lower risk for personality disorders and adjustment reactions among men. Personnel who served in ground war support occupations (men and women) were at greater risk for postwar drug-related disorders. Men who served in ground war combat occupations were at higher risk for alcohol-related disorders. Longitudinal studies of health, hospitalization, and exposure beginning at recruitment, are needed to better understand how exposure to combat affects the mental health of military personnel. 相似文献
75.
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
76.
The study was carried out to investigate the effect of ammonia inhalation on a total number of 60 male subjects from an urea production plant located in Alexandria. Laboratory investigations were carried out for 30 exposed and 30 controlled subjects. The results showed statistically significant inhibition (p<0.01) in the activity of catalase enzyme among the exposed than the control subjects. The inhibition could lead to deleterious effects on electrical stability, permeability and fluidity of membranes, which could affect the liver and brain to be more susceptible to hepatotoxic and neurotoxic alterations. The present work showed a significant inhibition (p<0.01) of monoamine oxidase (MAO) activities and significant increase (p<0.05, 0.01) in liver function activities among exposed subjects than the control subjects. 相似文献
77.
We studied 42 patients undergoing oral surgery under local anaesthesia with
i.v. sedation, allocated randomly to receive either methohexitone (group M)
or propofol (group P) for patient-controlled sedation (PCS). Group M
patients self-administered 2.5-mg (0.5 ml) bolus doses of methohexitone and
group P, 5-mg (0.5 ml) doses of propofol, without a lockout. The 0.5-ml
bolus dose was delivered over 7.2 s for both drugs. The procedure was
completed satisfactorily in all patients. Patients in both groups achieved
their desired levels of sedation. No patient lost verbal contact. Group M
patients had higher heart rates during the procedure. The lowest SpO2
values recorded were 92% and 95% for group P and group M, respectively.
Immediately after operation patients in group M reported that they felt
more sleepy than those in group P (P < 0.01) but there were no
differences at subsequent times. The results of the psychomotor tests were
comparable for the two groups after operation, except for the "posting box
task" at 15 min after operation when the mean decrement (compared with
preoperative performance) was - 3% for group P and -13% for group M (P <
0.05). More patients in group P complained of pain in their hand. We
conclude that methohexitone is a suitable alternative drug to propofol for
PCS.
相似文献
78.
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
79.
Influence of grass pollen immunotherapy on cellular infiltration and cytokine mRNA expression during allergen-induced late-phase cutaneous responses. 总被引:21,自引:4,他引:17
下载免费PDF全文
![点击此处可从《The Journal of clinical investigation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
V A Varney Q A Hamid M Gaga S Ying M Jacobson A J Frew A B Kay S R Durham 《The Journal of clinical investigation》1993,92(2):644-651
We have studied the influence of grass pollen immunotherapy on cellular infiltration and cytokine mRNA expression during allergen-induced late-phase cutaneous responses. In a double-blind, placebo-controlled trial of immunotherapy in 40 adult hay fever sufferers, clinical improvement was accompanied by a decrease in the size of the late-phase skin response. When the immunotherapy-treated group was compared with the placebo group, analysis of skin biopsies obtained 24 h after intradermal allergen revealed a significant reduction in the number of infiltrating CD3+ (P = 0.04) and CD4+ (P = 0.009) cells and a trend for a decrease in EG2+ eosinophils (P = 0.08). Treatment did not influence allergen-induced recruitment of CD8+ cells, neutrophils, or macrophages. Unexpected increases in expression of CD25 (P = 0.006) and HLA-DR (P = 0.007) were observed in the actively treated group. In situ hybridization using a panel of riboprobes demonstrated "TH2-type" (IL-4, IL-5) cytokine mRNA responses in both groups of patients. In contrast, significant hybridization for IL-2 (8/16 patients, P = 0.02) and for interferon-gamma (6/16 patients, P = 0.04) was observed only in the actively treated group. These findings indicate that immunotherapy is associated with suppression of allergen-induced CD4+ T lymphocyte infiltration, but among the cells that are recruited, there is upregulation of CD25 and HLA-DR. At least in this model, immunotherapy does not appear to affect expression of TH2-pattern cytokines in response to allergen exposure, but expression of mRNA for Th1-type cytokines was enhanced in half of the patients. The results support the view that immunotherapy may possibly be working through induction of T cell tolerance. 相似文献
80.
D M Grennan A F Ghobarey T Hadidi S El-Badawey H A Hamid W C Dick W W Buchanan 《Scottish medical journal》1977,22(2):139-145
The clinical features of 78 patients with SLE seen in Cairo and Glasgow are reviewed. Raynaud's phenomenon was recorded more frequently here than in previous series. The value of serial measurements of anti-DNA antibodies, C3 and C4 in the management of SLE is discussed. Although antibodies to native DNA paralleled the disease course in only a minority of SLE patients anti-DNA antibodies were present during all major SLE exacerbations and could be diagnostically useful. Serious systemic infections complicating the management of SLE patients could occur and their diagnosis is discussed. 相似文献