全文获取类型
收费全文 | 3022篇 |
免费 | 218篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 94篇 |
妇产科学 | 87篇 |
基础医学 | 465篇 |
口腔科学 | 32篇 |
临床医学 | 230篇 |
内科学 | 824篇 |
皮肤病学 | 117篇 |
神经病学 | 174篇 |
特种医学 | 73篇 |
外科学 | 355篇 |
综合类 | 22篇 |
预防医学 | 361篇 |
眼科学 | 52篇 |
药学 | 151篇 |
中国医学 | 22篇 |
肿瘤学 | 174篇 |
出版年
2023年 | 24篇 |
2022年 | 50篇 |
2021年 | 89篇 |
2020年 | 55篇 |
2019年 | 91篇 |
2018年 | 102篇 |
2017年 | 66篇 |
2016年 | 80篇 |
2015年 | 70篇 |
2014年 | 108篇 |
2013年 | 120篇 |
2012年 | 185篇 |
2011年 | 235篇 |
2010年 | 126篇 |
2009年 | 91篇 |
2008年 | 152篇 |
2007年 | 177篇 |
2006年 | 167篇 |
2005年 | 172篇 |
2004年 | 157篇 |
2003年 | 144篇 |
2002年 | 146篇 |
2001年 | 85篇 |
2000年 | 67篇 |
1999年 | 62篇 |
1998年 | 17篇 |
1997年 | 10篇 |
1996年 | 28篇 |
1995年 | 21篇 |
1994年 | 11篇 |
1993年 | 11篇 |
1992年 | 27篇 |
1991年 | 30篇 |
1990年 | 31篇 |
1989年 | 21篇 |
1988年 | 27篇 |
1987年 | 20篇 |
1986年 | 27篇 |
1985年 | 21篇 |
1984年 | 9篇 |
1983年 | 10篇 |
1979年 | 7篇 |
1978年 | 7篇 |
1977年 | 12篇 |
1975年 | 7篇 |
1974年 | 9篇 |
1972年 | 9篇 |
1971年 | 8篇 |
1969年 | 7篇 |
1966年 | 7篇 |
排序方式: 共有3252条查询结果,搜索用时 15 毫秒
1.
B. G. Salas-Salas D. J. Domnguez-Nuez R. Cabrera L. Ferrera-Alayn M. Lloret P. C. Lara 《Clinical & translational oncology》2020,22(1):151-157
Definitive radiotherapy is an effective single-modality in T1 glottic cancer. Hypofractionated schemes could offer excellent results in a shorter treatment period. We aimed to evaluate the clinical outcomes and toxicity comparing conventional vs. hypofractionated radiotherapy treatment in T1N0M0-glottic cancer. Between Jan-1st, 2005 and August-1st, 2017, in a prospective cohort study, with 10-year follow-up, 138 patients were treated with conventional schedule 2 Gy/day, total dose 70 Gy/7 weeks (N = 71) or hypofractionated schedule 2, 2–2, 25 Gy/day, total dose 63, 8–63 Gy/5, 5 weeks (N = 67). Endpoints were clinical-response rate, local relapse-free survival (LRFS), laryngectomy-free survival (LFS), toxicity rates, relapse-free survival (RFS), metastasis-free survival (MFS), second tumour-free survival (2TFS), and overall survival (OS). All patients showed a complete clinical response. No differences were found for LRFS (p = 0.869), LFS (p = 0.975), RFS (p = 0.767), MFS (p = 0.601), 2TFS (p = 0.293), or OS (p = 0.685). Acute toxicity for skin and mucosae was similar (p = 0.550 and p = 0.698). Acute laryngeal toxicity was higher in the hypofractionation group (p = 0.004), due to an increase in slight moderate grade. No differences in late laryngeal edema were found (p = 0.989). Radiotherapy offers high rate survival, local control, and larynx preservation after 5–10-year follow-up. A hypofractionation could be preferable, since it offers the same results as conventional with fewer treatment sessions. 相似文献
2.
3.
The observation that tumor cells of some neoplasms display major histocompatibility complex (MHC) class II molecules may be of functional significance, influencing the progression of malignancy by allowing the cancer cells to present antigen to the immune system. In the normal cervix, class II molecules are expressed by columnar but not squamous epithelium. The pattern of MHC class II expression in cervical carcinomas has been documented using immunohistochemical methods. Of 53 cervical squamous carcinomas examined for MHC class II expression, only 17% maintained a negative phenotype characteristic of the epithelium from which they were derived, while the remaining tumors exhibited either uniform (45%) or heterogeneous (38%) expression. Tumor areas which were class II positive also express class II associated invariant chain and the adhesion molecules lymphocyte function antigen 3 and intercellular adhesion molecule 1. The DR, DP, and DQ class II MHC subloci are differentially expressed, suggesting independent regulation. There is a trend for tumors with the uniform class II phenotype to predominantly express DR antigen, whereas tumors of the heterogeneous class II phenotype express with equal frequency either DR or DP antigens dominantly. There is no apparent influence of class II status on lymphocyte infiltration of the tumors. The presence of human papillomavirus 16 DNA in the cervical carcinoma specimens was analyzed by Southern blotting of restriction enzyme digested DNA and no correlation between the presence of human papilloma virus and MHC class II expression was found. 相似文献
4.
5.
Detection of Human T-Lymphotropic Virus (HTLV) tax Sequences in New York City Blood Donors Seronegative for HTLV Types 1 and 2
下载免费PDF全文
![点击此处可从《Clinical and Vaccine Immunology : CVI》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Charlene S. Dezzutti Patricia C. Guenthner Sylvester Daniel Ursula Utz Thania Cabrera James H. Marshall Celso Bianco Renu B. Lal Elliot P. Cowan 《Clinical and Vaccine Immunology : CVI》2003,10(4):715-717
A potential public health concern is the reported detection of the human T-lymphotropic virus (HTLV) tax gene in the lymphocytes of up to 11% of a low-risk group of New York City blood donors (NYBD). This study aimed to independently confirm the prevalence of HTLV tax sequences in 293 NYBD. All NYBD tested negative for antibodies to HTLV types 1 and 2 and HTLV Tax. HTLV tax sequences were not detected in the NYBD lymphocytes. These data demonstrate the lack of HTLV-1 tax in this group of NYBD at low risk for HTLV infection. 相似文献
6.
Acute epidural hematoma: an analysis of factors influencing the outcome of patients undergoing surgery in coma 总被引:4,自引:0,他引:4
R D Lobato J J Rivas F Cordobes E Alted C Perez R Sarabia A Cabrera I Diez P Gomez E Lamas 《Journal of neurosurgery》1988,68(1):48-57
Mortality due to epidural hematoma is virtually restricted to patients who undergo surgery for that condition while in coma. The authors have analyzed the factors influencing the outcome of 64 patients who underwent epidural hematoma evacuation while in coma. These patients represented 41% of the 156 patients operated on for epidural hematoma at their centers after the introduction of computerized tomography (CT). Eighteen patients (28.1%) died, two (3.1%) became severely disabled, and 44 (68.8%) made a functional recovery. The mortality rate for the entire series was 12%, significantly lower than the 30% rate observed when only angiographic studies were available. A significant correlation was found between the final result and the mechanism of injury, the interval between trauma and surgery, the motor score at operation, the hematoma CT density (homogeneous vs. heterogeneous), and the hematoma volume. The patient's age, the course of consciousness before operation (whether there was a lucid interval), and the clot location did not correlate with the final outcome. The mortality rate was significantly higher in patients operated on within 6 hours or between 6 and 12 hours after injury than in those undergoing surgery 12 to 48 hours after injury. Compared with the patients operated on later, the patients undergoing surgery in the early period were, on the average, older and had more rapidly developing symptoms, more pupillary changes, lower motor scores at surgery, larger hematomas, a higher incidence of mixed CT density clots, more severe associated intracranial lesions, and higher postoperative intracranial pressure (ICP). The mechanism of trauma seems to influence the course of consciousness before and after surgery. Passengers injured in traffic accidents had a lower incidence of a lucid interval and longer postoperative coma than patients with low-speed trauma, suggesting more frequent association of diffuse white matter-shearing injury. The duration of postoperative coma correlated with the morbidity rate in survivors. Forty-eight patients (75%) had one or more associated intracranial lesions, and 70% of these required treatment for elevation of ICP after hematoma evacuation. An ICP of over 35 mm Hg strongly correlated with poor outcome; administration of high-dose barbiturates was the only effective means for lowering ICP in nine of 15 patients who developed severe intracranial hypertension after surgery. This study attempts to identify patients at greater risk for presenting postoperative complications and to define a strategy for control CT scanning and ICP monitoring. 相似文献
7.
A Cabrera M Sánchez M A Izquierdo E Pastor J M Galdeano S Mintegui M A Lizarraga A Cuadrado M Ca?ada 《Revista espa?ola de cardiología》1992,45(10):637-644
Between 1985-1990 we studied by means of two-dimensional echocardiography 286 patients with isolated ventricular septal defect (VSD). A hundred and sixty three being male and 123 female, as a mean age of 5 +/- 3 months. Sixty two cases (22.3%) reveales associated anomalies and in other 63 (22.4%) there was in the evolution an aneurysm of the septum membranous. The projections used were apical 4-chamber, with or without aortic root; parasternal long-short axis of great arterias or at ventricular level; subcostal 4-chamber; right oblique outlet right outflow tract and left oblique outlet left and right outflow tracts. Patients with VSD smaller than 3 mm were excluded. Perimembranous defects, 189 cases (66%), were more frequent than muscular, 91 31.8%), and subarterial defects, 6 (2.1%). Only 19 (9 apical muscular, 6 perimembranous outlet and 4 perimembranous trabecular) were initially misclassified. The diameter of the VSD was large in subarterial (0.85 +/- 0.1 cm) and perimembranous outlet VSD (0.75 +/- 0.5 cm) compared with the rest. Each group of defects was more easily shown by one particular projection except trabecular muscular defect. In conclusion, we are able to state that two-dimensional echocardiography enables us to discover the size and situation of isolated ventricular defects. 相似文献
8.
Jesus Galvez Lourdes Cabrera Francisco Lajarin Pilar Garcia-Pearrubia 《Journal of immunological methods》1994,170(2):197-210
New methods for simplified quantitation of effector-target conjugation have been developed. The binding unit (BU) is defined as the number of target cells required to bind a specified percentage of effector cells. The number of binding units is determined from binding isotherms in which effector conjugate frequencies are measured by holding constant the number of effector cells and by varying the number of target cells. Alternately, a binding unit can be defined as the number of effector cells required to bind a specified percentage of target cells. In this case, BU is computed from binding isotherms in which target conjugate frequencies are measured at different values of effector cells by holding constant the number of target cells. Also, the area under the curve (AUI) of these isotherms is another index that can be used as an overall measure of the binding capacity in an effector-target system. The experimental values of BU and AUI determined from effector and target isotherms agree well with theoretical predictions based on our previously developed binding model (J. Immunol. Methods (1992) 155, 133–147). The relationship between BU and AUI, and procedures to determine these parameters are shown. The value of these indices to express effector-target conjugation quantitatively has been confirmed by determining the values of BU and AUI for the NK-K562 effector-target system. 相似文献
9.
The clinical and computed tomographic (CT) findings in a series of 161 consecutive patients operated upon for postraumatic extradural hematoma are analyzed. Thirteen (8%) patients had delayed epidural hematoma formation. The overall mortality for the series was 12%, significantly lower than that observed during the prior "angiographic" period at the same unit (30%). Because all but 1 of the deaths occurred among the 66 patients unconscious at the time of operation (27% mortality in this subgroup), the authors sought differential factors between comatose and noncomatose patients at operation. There were no significant differences between these groups in age, sex, mechanism of injury, preoperative course of consciousness (lucid interval or not), or epidural hematoma location and shape. In contrast, significant differences were seen between the two subgroups in trauma-to-operation interval, hematoma volume, CT hematoma density (mixed low-high CT density vs. homogeneous hyperdensity), midline displacement, severity of associated intracranial lesions, and postoperative intracranial pressure (ICP). Patients comatose at operation usually evidenced a more rapid clinical deterioration (a shorter trauma-to-operation interval) and tended to have a large hematoma volume, a higher incidence of mixed CT density clot (hyperacute bleeding), more marked shift of midline structures, more severe associated lesions, and higher postoperative ICP levels. 相似文献
10.
P. A. Gómez R. D. Lobato J. J. Rivas A. Cabrera R. Sarabia S. Castro M. Castañeda J. M. Cañizal 《Acta neurochirurgica》1989,101(1-2):35-41
Summary The authors review the literature on subarachnoid haemorrhage of unknown aetiology (SAHUE) and analyze a personal series of 212 patients diagnosed as SAHUE. These patients represent 30% of all cases of primary SAH admitted over a 14.5 year period.The age, sex, antecedents and initial clinical presentation of patients with SAHUE were indistinguishable from those of patients with subarachnoid haemorrhage due to ruptured aneurysm (SAHRA). However, the present series of SAHUE compare favourably with both a personal and a previously reported series of SAHRA insofar as clinical grade on admission (94% of patients in grades I–II of Botterell), presence of blood on CT (51%), vasospasm (5%), ischaemic deficits (3.3%), persistent hydrocephalus (3.5%), rebleeding (6%) and fatal result (3.9%) are concerned.The amount of blood on CT scan in our patients with SAHUE was associated with a significantly higher incidence of brain ischaemia and hydrocephalus but did not correlate with the Botterell grade on admission or final outcome, which were good in the majority of cases regardless of the presence or not of visible cisternal haemorrhage. The results of the present series confirm that the final prognosis of patients with primary SAH showing normal four-vessel cerebral angiography is essentially favourable. 相似文献