全文获取类型
收费全文 | 6265篇 |
免费 | 385篇 |
国内免费 | 42篇 |
专业分类
耳鼻咽喉 | 86篇 |
儿科学 | 113篇 |
妇产科学 | 106篇 |
基础医学 | 818篇 |
口腔科学 | 123篇 |
临床医学 | 541篇 |
内科学 | 1395篇 |
皮肤病学 | 246篇 |
神经病学 | 456篇 |
特种医学 | 194篇 |
外科学 | 1000篇 |
综合类 | 202篇 |
一般理论 | 4篇 |
预防医学 | 332篇 |
眼科学 | 232篇 |
药学 | 224篇 |
中国医学 | 11篇 |
肿瘤学 | 609篇 |
出版年
2023年 | 44篇 |
2022年 | 92篇 |
2021年 | 193篇 |
2020年 | 111篇 |
2019年 | 145篇 |
2018年 | 178篇 |
2017年 | 113篇 |
2016年 | 136篇 |
2015年 | 189篇 |
2014年 | 217篇 |
2013年 | 299篇 |
2012年 | 482篇 |
2011年 | 438篇 |
2010年 | 268篇 |
2009年 | 237篇 |
2008年 | 361篇 |
2007年 | 392篇 |
2006年 | 385篇 |
2005年 | 322篇 |
2004年 | 314篇 |
2003年 | 268篇 |
2002年 | 257篇 |
2001年 | 120篇 |
2000年 | 133篇 |
1999年 | 105篇 |
1998年 | 47篇 |
1997年 | 55篇 |
1996年 | 42篇 |
1995年 | 37篇 |
1994年 | 36篇 |
1993年 | 49篇 |
1992年 | 57篇 |
1991年 | 64篇 |
1990年 | 61篇 |
1989年 | 38篇 |
1988年 | 46篇 |
1987年 | 33篇 |
1986年 | 35篇 |
1985年 | 27篇 |
1984年 | 22篇 |
1983年 | 27篇 |
1982年 | 15篇 |
1981年 | 18篇 |
1980年 | 11篇 |
1979年 | 13篇 |
1978年 | 15篇 |
1977年 | 18篇 |
1976年 | 15篇 |
1975年 | 12篇 |
1973年 | 16篇 |
排序方式: 共有6692条查询结果,搜索用时 15 毫秒
1.
S C Chua A W Brown J Kim K L Hennessey R L Leibel J Hirsch 《Brain research. Molecular brain research》1991,11(3-4):291-299
We have used a novel method to identify genes expressed in the hypothalamus which may be potentially involved in controlling food intake and energy metabolism. We assumed that food deprivation, a powerful stimulus of food intake, would stimulate the activity of neural pathways involved in feeding behavior which should be reflected in an increase in the synthesis of any relevant neuropeptide and its messenger RNA. A study of 5 neuropeptides in 5 strains of mice has identified neuropeptide Y (NPY) as a gene whose expression in the hypothalamus is controlled by nutritional status, suggesting that hypothalamic NPY neurons are a link in the neural network regulating feeding behavior and energy metabolism. In addition, we have studied the effect of the diabetes mutation on neuropeptide gene expression during fasting and refeeding. Our findings suggest that abnormal NPY and enkephalin gene expression in the hypothalamus may be two important determinants of the expression of the diabetes mutation. 相似文献
2.
From 1974 to 1983, simple and radical nephrectomies were performed at the Chaim Sheba Medical Center (Tel Hashomer, Israel) for renal cell carcinoma. The authors reviewed 109 cases that were followed for a period ranging from 5 to 14 years. Simple nephrectomy was performed in 55 patients, and 54 patients underwent radical nephrectomy. The selection of the surgical procedure was based on the surgeon's preference and not on the basis of clinical stage, age, or sex. The surgical results and survival rates were assessed according to the pathologic stage of the tumors. Among patients with Stage I tumor, radical nephrectomy produced better survival rates at 5 and 10 years (P = 0.03); however, when the non-cancer deaths were excluded, the difference in survival was not statistically significant. For Stage I tumors the survival free of disease at 5 years was better for the radical nephrectomy group, but this difference was not statistically significant. No difference was noticed in the local recurrence rate between the two groups. Nephrectomy in patients with Stage IV disease did not alter survival regardless of the type of operation. 相似文献
3.
Borras Merce; Valdivielso Jose M.; Egido Ramon; Vicente de Vera Pilar; Bordalba Josep Ramon; Fernandez Elvira 《Nephrology, dialysis, transplantation》2006,21(3):789-791
4.
Duplication of the urethra with an accessory phallic urethra in females is a rare anomaly usually discovered early in life because of associated genitourinary anomalies. We report on a thirty-three-year-old female with this anomaly who presented with double urinary stream and recurrent urinary tract infections. The nature of this anomaly, its diagnosis, and management are reviewed. 相似文献
5.
Ramon Edmundo D Bautista Steven Godwin David Caro 《Journal of clinical neurophysiology》2007,24(1):16-21
Patients frequently present to the emergency room (ER) with mental status changes without obvious cause. The EEG is underused in this population. The authors investigated whether an abbreviated EEG (AbEEG) can be incorporated in the early evaluation of these patients to provide useful information. A 5-minute AbEEG was performed using a preformed electrode placement system on 25 patients who presented to the ER with mental status changes of unknown cause. AbEEG findings were categorized as normal, showing diffuse abnormalities, focal abnormalities, electrographic seizures, or uninterpretable. Using retrospective chart review, the authors determined if the cause of mental status change was a diffuse encephalopathy or a nonneurologic event (DENNE), a focal brain abnormality, nonconvulsive status epilepticus (NCSE), psychogenic, or unknown, and if particular AbEEG findings were associated with specific causes of altered sensorium. The AbEEG identified NCSE in two patients who presented with new-onset seizures. The presence of diffuse slowing on the AbEEG was highly suggestive of mental status changes due to DENNE. AbEEGs can be successfully incorporated in the early evaluation of patients who present to the ER with mental status changes of unknown cause and provide useful information in this setting. 相似文献
6.
Food deprivation and age modulate neuropeptide gene expression in the murine hypothalamus and adrenal gland. 总被引:1,自引:0,他引:1
We have developed a rapid and simple method for quantitative Northern blot analysis of rare messenger RNA species from single mouse hypothalami and adrenals. This technique has allowed us to study the effects of food deprivation on neuropeptide gene expression in the mouse hypothalamus and adrenal gland. The potential modulatory effects of sex and age were also investigated. Food deprivation induced a two-fold increase in the amount of hypothalamic neuropeptide Y (NPY) mRNA, but did not increase NPY mRNA in the brainstem. Age had a significant effect on levels of NPY messenger RNA levels in the hypothalamus. However, there were no gender-associated effects. Sexually immature females (6 weeks old) had higher levels of NPY expression than mature females (9 weeks old). In contrast, in the adrenal gland, increasing maturity was associated with higher levels of NPY mRNA. As in the hypothalamus, fasting caused approximately two-fold increases in NPY mRNA over levels in the ad libitum fed state for both mature and immature mice. Thus, hypothalamic NPY neurons are responsive to nutritional deprivation and developmental status, suggesting that NPY neurons may be important in energy homeostasis. 相似文献
7.
Kimberly M Miller Michael S Okun Hubert F Fernandez Charles E Jacobson Ramon L Rodriguez Dawn Bowers 《Movement disorders》2007,22(5):666-672
Depression is common in Parkinson's disease (PD) and affects 30 to 50% of all patients. In contrast to the wealth of research on depression in PD, little is known about the occurrence of depression in other movement disorders. The primary objective of the current study was to determine whether the high prevalence of depression symptoms seen in PD is also found in other movement disorders, by directly comparing rates of specific depression symptoms and depression severity across PD, dystonia, and essential tremor (ET). Three hundred and fifty-four patients with PD, 83 patients with dystonia, and 53 patients with ET completed the Beck Depression Inventory (BDI). We found no significant between-groups differences for depression severity, frequency, or endorsement of specific depression symptoms. Forty-eight percent of PD patients, 37.3% of dystonia patients, and 34% of ET patients were found to be at least mildly depressed (BDI score of 10 or higher). The most commonly endorsed symptoms were fatigability, difficulty with work, anhedonia, and sleep disturbance. Clinicians should be aware that depression is a frequent problem in dystonia and ET, in addition to PD, and inquire about depression symptoms in these patients so that they can be appropriately treated. 相似文献
8.
F. Fabris I. Cordiano F. Salvan R. Ramon M. Valente G. Luzzatto A. Girolami 《European journal of haematology》1997,58(1):40-45
Abstract: We studied 47 subjects belonging to 13 unrelated families with a history of mild haemorrhagic diathesis and chronic thrombocytopenia. 36 patients presented some degree of thrombocytopenia: 7/36 (19%) had slight thrombocytopenia (100–150×109/L); 26/36 (72%) had mild thrombocytopenia (50–100×109/L) and 3/36 (8%) had severe thrombocytopenia (<50×109/L). No correlation was observed between platelet count and the degree of haemorrhagic diathesis, which was mild in the majority of patients. Transmission was autosomal dominant. Platelet anisocytosis, increased percentage of large platelets and absence of leukocyte inclusions were observed in 26/30 (87%) of the examined blood smears. The ultrastructural appearance of platelets was normal. Megakaryocytes appeared normal in number in 10/10 patients, but showed asynchronous nuclear-cytoplasm maturation and mainly nonlobulated nuclei. Platelet aggregation was studied in 26 patients and either increased or decreased curves were variably observed in response to different aggregating agents. Platelet-associated IgG (PAIgG) was increased in 18/31 (58%) patients, while serum autoantibodies against platelet glycoproteins Ib/IX or IIb/IIIa were demonstrable in only 1 case. An increased expression of platelet surface glycoproteins Ib and IIb/IIIa, as studied by murine monoclonal antibodies binding in 17 cases, was observed. Platelet survival performed by 111In-oxine-labelled autologous platelets was normal in the 3 studied patients. Congenital macrothrombocytopenia confirms to be a distinct clinical disorder for which the name of “chronic isolated hereditary macrothrombocytopenia” is proposed. 相似文献
9.
Juan M. Verdeguer M.D. Dolores Ramon M.D. Manuel Moragon M.D. Isabel Betlloch M.D. Esperanza Jorda M.D. M.D Victoria Planelles M.D. † 《Pediatric dermatology》1988,5(1):56-57
Abstract: Hydantoin is an anticonvulsant drug with several side effects. A teralogenic potential has been suggested. The fetal hydantoin syndrome is an entity that consists of a broad range of morphologic and developmental disorders in children born of epileptic mothers exposed to hydantoin during pregnancy. We treated a girl in whom onychopathy was a monosymptomatic or mild form of this syndrome. 相似文献
10.
We studied 12 non-demented PD patients in on state before and 3 months after posteroventral pallidotomy (PVP), in order to evaluate the effects of surgery upon an unconstrained, multijoint skilled movement as well as a single joint, repetitive, ballistic movement. A Selspot II System was used for three-dimensional data acquisition, processing and reconstruction of limb trajectories. Specific wrist kinematic features of spatial accuracy (linearity and planarity), temporal attributes (acceleration and velocity), spatiotemporal relationships (velocity-curvature coupling), and joint kinematic variables (relationships between wrist and elbow velocities and relative arm angle amplitudes) for each cycle of movement were graphically and numerically analysed. QMC was applied to single joint, repetitive, ballistic movements. QMC significantly improved after PVP (P < 0.0006). However, wrist as well as joint kinematic variables of the gestural movements failed to change significantly after PVP. The lack of improvement of the kinematic abnormalities of the gestural movement in PD patients would indicate that they are unrelated to the basic motor deficit; most likely they are the result of a disruption of a complex of sensorimotor integration processes due to abnormal parieto-frontal basal ganglia interaction. 相似文献