全文获取类型
收费全文 | 11936篇 |
免费 | 557篇 |
国内免费 | 114篇 |
专业分类
耳鼻咽喉 | 95篇 |
儿科学 | 252篇 |
妇产科学 | 305篇 |
基础医学 | 1313篇 |
口腔科学 | 229篇 |
临床医学 | 1104篇 |
内科学 | 3351篇 |
皮肤病学 | 149篇 |
神经病学 | 1230篇 |
特种医学 | 513篇 |
外科学 | 1592篇 |
综合类 | 31篇 |
预防医学 | 498篇 |
眼科学 | 152篇 |
药学 | 701篇 |
中国医学 | 25篇 |
肿瘤学 | 1067篇 |
出版年
2024年 | 9篇 |
2023年 | 84篇 |
2022年 | 185篇 |
2021年 | 311篇 |
2020年 | 215篇 |
2019年 | 231篇 |
2018年 | 296篇 |
2017年 | 213篇 |
2016年 | 267篇 |
2015年 | 318篇 |
2014年 | 432篇 |
2013年 | 556篇 |
2012年 | 925篇 |
2011年 | 925篇 |
2010年 | 508篇 |
2009年 | 545篇 |
2008年 | 869篇 |
2007年 | 848篇 |
2006年 | 866篇 |
2005年 | 804篇 |
2004年 | 684篇 |
2003年 | 587篇 |
2002年 | 586篇 |
2001年 | 87篇 |
2000年 | 67篇 |
1999年 | 76篇 |
1998年 | 118篇 |
1997年 | 99篇 |
1996年 | 87篇 |
1995年 | 75篇 |
1994年 | 53篇 |
1993年 | 70篇 |
1992年 | 79篇 |
1991年 | 45篇 |
1990年 | 53篇 |
1989年 | 53篇 |
1988年 | 41篇 |
1987年 | 37篇 |
1986年 | 24篇 |
1985年 | 25篇 |
1984年 | 28篇 |
1983年 | 26篇 |
1982年 | 26篇 |
1981年 | 23篇 |
1980年 | 27篇 |
1979年 | 9篇 |
1978年 | 12篇 |
1977年 | 9篇 |
1974年 | 11篇 |
1971年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
Giant abdominopelvic epithelioid angiomyolipoma associated with tuberous sclerosis: Report of a case
Giorgio Di Matteo Alessandro Maturo Antonella Marzullo Nadia Peparini Bianca Martin Wedard Kenneth Paul Zeri Filippo Maria Di Matteo Domenico Mascagni 《Surgery today》1999,29(11):1183-1188
(Received for publication on July 16, 1998; accepted on Mar. 11, 1999) 相似文献
82.
Corsonello A Pedone C Corica F Malara A Carosella L Sgadari A Mauro VN Ceruso D Pahor M Carbonin P 《European journal of epidemiology》1999,15(10):893-901
We performed this case–control study to evaluate the risk of hypoglycemia associated with the use of antihypertensive drugs in older hospitalized diabetic patients treated with sulfonylureas and/or insulin. All diabetic patients admitted during 4 months in 1988, 1 month in 1991, 4 months in 1993 and 4 months in 1995 (n = 3477, mean age 71.4 ± 0.2 years, 1542 males and 1935 females) were enrolled in the study. During the four annual surveys 86 patients (mean age 71.1 ± 1.4 years, 33 males and 53 females) presented hypoglycemia during hospital stay. The patients who presented hypoglycemia were less frequently users of sulfonylureas and more frequently users of a combination of insulin and sulfonylureas. Use of antihypertensive drugs was similar in the two groups studied, and among potentially interacting drugs considered in the analysis, sulfonamides were more frequently used in patients who experienced hypoglycemia. Moreover, patients with hypoglycemia used a higher number of drugs, had a longer length of stay and had a greater prevalence of hypoglycemia as admission problem. Finally, although not significant, liver and renal diseases were more frequent among patients with hypoglycemia. In the multivariate analysis, contemporary use of insulin and sulfonylureas, liver disease and length of stay were significantly associated with hypoglycemia, while none of the antihypertensive drugs showed a significant association with the occurrence of hypoglycemia during hospital stay. Our results indicate that antihypertensive drugs do not increase the risk of hypoglycemia in elderly diabetic patients. 相似文献
83.
Roberto Ciccocioppo Izabela Panocka Carlo Polidori Domenico Regoli M. Massi 《Psychopharmacology》1999,141(2):220-224
The present study investigated the effect of nociceptin (NC), the endogenous ligand of the opioid-like orphan receptor ORL1,
on ethanol intake in genetically selected Marchigian Sardinian alcohol-preferring (msP) rats. Acute intracerebroventricular
(ICV) injection of 250 or 500 ng/rat of NC, just before access to 10% ethanol (offered 2 h/day), significantly increased ethanol
intake. Subchronic (7 days) ICV injection of 500 ng/rat of NC, given just before access to 10% ethanol (for 30 min/day), resulted
in a progressive decrease in ethanol consumption. After the end of NC treatment, rats progressively recovered their usual
ethanol intake. When NC, 500 or 1000 ng/rat, was tested versus the effect of ethanol in the place conditioning paradigm, NC
significantly reduced the increase in time spent in the ethanol-paired compartment after conditioning. This finding suggests
that NC reduces the rewarding properties of ethanol in msP rats; thus, they may respond to the acute NC administration by
increasing their ethanol intake in an attempt to achieve the usual reinforcing effect of ethanol, whereas subchronic NC treatment
may result in extinction of ethanol drinking. The results of the present study suggest that the brain NC mechanisms may represent
an interesting target of pharmacological interventions for the treatment of alcoholism.
Received: 11 August 1998/Final version: 15 October 1998 相似文献
84.
Clinicopathological study of familial late infantile Hallervorden-Spatz disease: a particular form of neuroacanthocytosis 总被引:1,自引:0,他引:1
Alessandro Malandrini Gian Maria Fabrizi Paola Bartalucci Claudio Salvadori Gianna Berti Gian Carlo Guazzi Claudio Sabò 《Child's nervous system》1996,12(3):155-160
The cases of two sisters with late infantile Hallervorden-Spatz disease are reported, one of whom has died. Autopsy of the deceased patient showed typical pallidal lesions, such as axonal spheroids and iron deposits, without involvement of the substantia nigra. Ultrastructural examination revealed that pallidal axonal enlargements consisted of collecition of mitochondria, dense bodies, vesicles and amorphous material. In the living patient, brain MRI showed the classical tiger's eye appearance of the globus pallidus. Retinitis pigmentosa, acanthocytosis and slight neuromuscular involvement with an increase in serum creatine kinase were observed in both subjects. The appearance of the globus pallidus on MRI was in line with the pathological abnormalities. Ultrastructural differences between the principal disorders characterized by neuroaxonal dystrophy are compared and the clinical spectrum and similarities of the different forms of neuroacanthocytosis analysed. 相似文献
85.
Andrea Bonetti Marta Zaninelli Stefania Rodella Annamaria Molino Loris Sperotto Quirino Piubello Franco Bonetti Rolando Nortilli Monica Turazza Gian Luigi Cetto 《Breast cancer research and treatment》1996,38(3):289-297
Summary The relationship between tumor proliferative activity and response to first-line chemotherapy and survival was investigated in 76 advanced breast cancer patients. Proliferative activity was determined by means of Ki-67 immunohistologic staining on primary tumors (55 patients) or at the relapse site (21 patients), and was classified as low ( 25% of stained cells) or high (> 25% of stained cells). The usual WHO response criteria were used. The median duration of follow-up was 18 months (range 3–58).Forty-seven patients (62%) had tumors with low, and 29 (38%) had tumors with a high rate of proliferative activity. The two groups were well balanced in terms of important variables such as disease-free survival, performance status, age, menopausal status, and the type of first-line chemotherapy (anthracycline-based regimens versus cyclophosphamide-methotrexate-5-fluorouracil). The estrogen receptor (ER) content, measured by means of immunohistochemical assay, was markedly different in the two groups, with 27/47 tumors with low proliferative activity (57%) and 6/29 with high-proliferative activity (21%) being ER positive ( 45% of stained cells) (p = 0.003). Moreover, a significant difference in the metastatic pattern was also evident, with a higher incidence of bone and a lower incidence of soft tissue metastases in the group of patients with tumors with low proliferative activity (p = 0.004). Overall, 10/47 responses (21%: PR = 7, and CR = 3) were observed in the group with a low rate of proliferative activity, versus 14/29 (48%: PR = 9, and CR = 5) in the group with highly proliferative tumors, the difference being statistically significant (p = 0.03). When a multivariate analy-sis was performed, the only factor that retained independent prognostic significance was the predominant site of disease, particularly soft tissues (p = 0.003). Despite the difference in response rate, when survival analysis was performed according to the Kaplan-Meier method, no significant difference was observed in the two groups, but when the analysis was limited to responsive patients, the median survival observed in those with a low and those with a high rate of proliferation was 35 and 19 months respectively (p = 0.02). The same results were obtained when multivariate survival analysis was carried out using Cox's regression model. These data suggest that there is a link between tumor proliferative activity and response to chemotherapy in advanced breast cancer, and may indicate the need to use more intensive treatments in selected patients with highly proliferative tumors.Presented in part at the Annual Meeting of the American Society of Clinical Oncology, May 14–17, 1994, Dallas, TX, USA 相似文献
86.
Pierpaolo Lunardi Luciano Mastronardi Jibril Osman Farah Claudio De Biase Guido Trasimeni Gian F. Gualdi 《Neurosurgical review》1996,19(3):175-178
The case of a young patient with left accessory nerve paralysis is reported. He had slight tilting of the head to the right side, developed over a period of about 6 months. On neurological examination hypotrophy of the left sternocleidomastoid and trapezius muscles was observed. MRI and MR-angiography imaged the presence of a neurovascular compression between the medulla oblungata, at the level of the nerve entry zone, and a vessel loop of an elongated left vertebral artery. In spite of the absence of a surgical demonstration it is our opinion that the neurovascular conflict is the cause of the accessory nerve palsy. 相似文献
87.
Rocco Cicciarello Maria E. Gagliardi Francesca Albiero Mario Mesiti Antonio d'Aquino Emilia Ciriaco Giovanni Germana Emanuele Cardia Domenico d'Avella 《Child's nervous system》1993,9(1):25-27
Employing quantitative autoradiography, pineal body glucose utilization (GU) was measured in daytime or at night in prepubertal (aged 1 month), adult (aged 3 months), and mature (over 12 months old) rats. In prepubertal and adult rats, in daytime, GU values within the pineal tissue were homogeneously distributed around 65 mol glucose/100 g per min. In prepubertal animals no significant variations in GU were observed between daytime and nocturnal measurements. A circadian metabolic rhythmicity was evident in adult rats, with a GU peak measured at 2 a.m. In mature animals, GU also varied between day and night, with an increment in the relative difference between the two values. The present investigation is the first to demonstrate that circadian metabolic rhythmicity is absent before sexual maturation while it is enhanced in 12-month-old rats. These changes in pineal energy metabolism with advancing age are intriguing in view of the concept that the pineal gland may be involved in functional changes occurring during the process of aging. 相似文献
88.
Early MRI findings in Creutzfeldt-Jakob disease 总被引:1,自引:0,他引:1
Marco Onofrj Tommaso Fulgente Domenico Gambi Giorgio Macchi 《Journal of neurology》1993,240(7):423-426
We describe the MRI changes preceding the onset of myoclonus in two patients whose post-mortem examination confirmed the diagnosis of Creutzfeldt-Jakob disease (CJD). MRI showed changes in the striatum early in the course of CJD (2–6 months after the onset of apathy, interpreted as depression, and 1–2 months before the onset of further clinical symptoms). Only in one patient did electroencephalography record the typical triphasic sharp-waves, 1 month after MRI. 相似文献
89.
Evaluation of vesico-urethral and sweating function in disorders presenting with parkinsonism 总被引:1,自引:0,他引:1
Milena De Marinis Guido Argenta Domenico Mele Antonio Carbone Giulio Baffigo Alessandro Agnoli 《Clinical autonomic research》1993,3(2):125-130
Investigation of vesico-urethral and sweating function was performed in twelve patients with classical idiopathic Parkinson's disease and ten patients with parkinsonism associated with features suggestive of more extensive involvement of the nervous system, as in the Shy—Drager syndrome. The urodynamic studies revealed detrusor hyperreflexia with reduction of maximal cystometric capacity in only one patient with Parkinson's disease (8%), but in nine patients with parkinsonism associated with other features (90%). Urethral sphincter electromyography did not indicate denervation in any patient of either group. Delayed or incomplete relaxation of the urethral sphincter during micturition was observed in seven patients with Parkinson's disease (58%) and in two patients of the other group (20%). Decreased sweating responses were found in both groups of patients when compared with control subjects. Hypohidrosis was more pronounced in parkinsonism associated with other features than in Parkinson's disease. Differences in sweating between the two sides of the body were observed in both groups of patients. Although there are differences in vesico-urethral and sweating function, they do not precisely differentiate between patients with classical Parkinson's disease and those with parkinsonism associated with features suggestive of more extensive involvement of the nervous system. 相似文献
90.
Anna Scattone Gilda Caruso Andrea Marzullo Domenico Piscitelli Mattia Gentile Lucia Bonadonna Giuseppe Balducci Maria Cristina Digilio Alessandro Jenkner Francesca Diomedi Camassei Renata Boldrini Pietro Nazzaro Lucio Pollice Gabriella Serio 《Fetal and pediatric pathology》2003,22(4):323-341
Deletion 22q11.2 is a chromosomal abnormality detected in young patients with clinical manifestations of the DiGeorge/velocardiofacial syndrome. Conotruncal heart defects are also associated with del22q11.2. An association of these cardiac malformations with neoplasias has been observed. Our series includes two cases of malignancies, a hepatoblastoma and a renal-cell carcinoma, arising in children with complex cardiac malformations. The aim of the study was to determine if the deletion at 22q11.2 was present and could be responsible for both pathological processes. Del22q11.2 was identified in both cases. Comparative genomic hybridization revealed terminal gains on chromosomes 1q and Xq and terminal loss on 1p in the hepatoblastoma, and gains in 1p, 12q, 16p, 20q, 22q, and whole chromosome 19 and loss of Xq in the renal-cell carcinoma. Our results confirm a common genetic basis for cardiac malformations, and del22q11.2 presents a risk factor for the development of pediatric tumours. 相似文献