全文获取类型
收费全文 | 57865篇 |
免费 | 3979篇 |
国内免费 | 224篇 |
专业分类
耳鼻咽喉 | 684篇 |
儿科学 | 1475篇 |
妇产科学 | 1094篇 |
基础医学 | 7252篇 |
口腔科学 | 948篇 |
临床医学 | 5609篇 |
内科学 | 11838篇 |
皮肤病学 | 711篇 |
神经病学 | 5550篇 |
特种医学 | 1947篇 |
外国民族医学 | 4篇 |
外科学 | 9791篇 |
综合类 | 814篇 |
现状与发展 | 1篇 |
一般理论 | 69篇 |
预防医学 | 5129篇 |
眼科学 | 1180篇 |
药学 | 3553篇 |
中国医学 | 62篇 |
肿瘤学 | 4357篇 |
出版年
2023年 | 220篇 |
2022年 | 423篇 |
2021年 | 996篇 |
2020年 | 561篇 |
2019年 | 948篇 |
2018年 | 1157篇 |
2017年 | 799篇 |
2016年 | 893篇 |
2015年 | 994篇 |
2014年 | 1645篇 |
2013年 | 2437篇 |
2012年 | 3587篇 |
2011年 | 3886篇 |
2010年 | 2192篇 |
2009年 | 2020篇 |
2008年 | 3510篇 |
2007年 | 3689篇 |
2006年 | 3665篇 |
2005年 | 3749篇 |
2004年 | 3680篇 |
2003年 | 3360篇 |
2002年 | 3290篇 |
2001年 | 476篇 |
2000年 | 364篇 |
1999年 | 571篇 |
1998年 | 749篇 |
1997年 | 635篇 |
1996年 | 572篇 |
1995年 | 540篇 |
1994年 | 482篇 |
1993年 | 440篇 |
1992年 | 362篇 |
1991年 | 372篇 |
1990年 | 300篇 |
1989年 | 303篇 |
1988年 | 288篇 |
1987年 | 275篇 |
1986年 | 256篇 |
1985年 | 303篇 |
1984年 | 469篇 |
1983年 | 398篇 |
1982年 | 522篇 |
1981年 | 509篇 |
1980年 | 495篇 |
1979年 | 250篇 |
1978年 | 293篇 |
1977年 | 284篇 |
1976年 | 221篇 |
1975年 | 218篇 |
1974年 | 235篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
191.
Steven C. Cunningham M.D. Farin Kamangar M.D. M.P.H. Min P. Kim M.D. Sommer Hammoud Raqeeb Haque Anirban Maitra M.B.B.S. Elizabeth Montgomery M.D. Richard E. Heitmiller M.D. F.A.C.S. Michael A. Choti M.D. F.A.C.S. Keith D. Lillemoe M.D. F.A.C.S. John L. Cameron M.D. F.A.C.S. F.R.C.S. F.R.C.S.I. Charles J. Yeo M.D. F.A.C.S. Richard D. Schulick M.D. F.A.C.S. 《Journal of gastrointestinal surgery》2005,9(5):718-725
Gastric adenocarcinoma is the second leading cause of cancer death worldwide. In Western series, survival rates vary widely
and are generally lower than those reported from Eastern series. We performed a retrospective analysis of cases operated on
at the Johns Hopkins Hospital over the past 18 years and collected data on demographics, tumor characteristics, pathologic
stage, treatment methods, complications, survival time, and other relevant factors. Survival according to stage of disease,
Lauren tumor type, tumorlocation,time period, andadministration of adjuvant therapy wasanalyzed, andresultswerecompared with
those of other Western series. During this period, 436 patients with gastric adenocarcinoma underwent resection. We have shown
a statistically significant association between survival and margin status, stage of disease, and Lauren tumor type. Overall
5-year survival was 26%, and 5-year survival after R0 resection was 33%. No significant difference was detected between survival
and tumor location, time period of treatment, or administration of adjuvant therapy. Analysis of various Western series reveals
major differences between the cohorts under study, such as stage of disease, extent of resection, tumor type, and tumor location.
Many of the reported differences among Western series may be due to cohort differences, such as stage of disease, extent of
resection, tumor type, and tumor location. 相似文献
192.
Susanna L. Matsen Charles J. Yeo Ralph H. Hruban Michael A. Choti 《Journal of gastrointestinal surgery》2005,9(2):270-279
Humoral hypercalcemia of malignancy is widely associated with tumor production of parathyroid hormone related protein (PTH-rP).
This peptide functions in endocrine, autocrine and paracrine mechanisms in a manner similar to PTH; increasing renal uptake
of calcium, decreasing retention of phosphorous, and stimulating adenylate cyclase and phospholipase C. Although PTH-rP production
has been well documented in neoplasms of the exocrine pancreas, we present here two cases of endocrine pancreatic neoplasms
elaborating PTH-rP. We then review the literature of previous cases and delve into the pathophysiology of this peptide. 相似文献
193.
Furtado de Medeiros Charles Angotti MSc Luccas George Carchedi PhD 《Dermatologic surgery》2005,31(12):1685-1694
BACKGROUND: Patients with varicose veins seek medical assistance for many reasons, including esthetic ones. The development of suitable and more flexible instruments, along with less invasive techniques, enables the establishment of new therapeutic procedures. OBJECTIVE: To compare endovenous great saphenous vein photocoagulation with an 810 nm diode laser and the conventional stripping operation in the same patient. METHODS: Twenty patients selected for operative treatment of primary great saphenous vein insufficiency on duplex scanning were assigned to a bilateral random comparison. In all cases, both techniques were performed, one on each lower limb. Clinically, evaluation was assessed on the seventh, thirtieth, and sixtieth postoperative days. Patients underwent examination with duplex ultrasonography and air plethysmography during the follow-up. RESULTS: Patients who received endovenous photocoagulation presented with the same pain but fewer swellings and less bruising than the stripping side. Most patients indicated that the limb operated on by laser received more benefits than the other. There was only one recanalization and no adverse effects. The venous filling time showed better hemodynamics in both techniques. CONCLUSION: The endovenous great saphenous vein photocoagulation is safe and well tolerated and presents results comparable to those of conventional stripping. 相似文献
194.
Background: One hypothesis for the pathogenesis of keratoconus includes teenage allergy, ocular itch and associated eye‐rubbing. Methods: This study examined the prevalence of these factors for teenage and adult patients. The results for a sample of 53 subjects with bilateral keratoconus were compared with those for a control sample of non‐keratoconus subjects, who also routinely wore RGP contact lenses. The strongest dominant hand and the eye with more advanced keratoconus were also determined, to examine for a relationship between them. Results: The keratoconic sample reported significantly higher levels of allergy, itch and rubbing as teenagers and as adults. However, all distributions were bimodal, consistent with the hypothesis that allergy, itch and rubbing are relevant in the pathogenesis of keratoconus only when the highest levels of these factors are present. For example, a significant relationship between the stronger dominant hand and the more advanced eye was evident only in subjects who reported the most severe rubbing. Conclusions: This finding adds weight to the circumstantial evidence that rubbing contributes to the pathogenesis of keratoconus. Low levels of teenage rubbing by some keratoconic subjects suggest a non‐rubbing pathogenesis and that emphasis on rubbing management is not warranted in these cases. However, high levels of adult rubbing reported by many keratoconic subjects indicate that the standard advice to avoid vigorous and prolonged rubbing is often not effective, even when repeated. There appears to be an indication for the need to improve the management of eye‐rubbing for some patients with keratoconus or at risk of developing this disease. 相似文献
195.
Joseph C Whitt Charles L Dunlap John L Sheets Michael L Thompson 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,104(3):368-376
The term keratoameloblastoma has been used to describe a histologically heterogeneous group of ameloblastoma variants which have in common the formation of keratin by the ameloblastomatous epithelium. The English language literature contains reports of only 12 cases of keratoameloblastoma, of which 4 cases exhibited a papilliferous component. We report a unique tumor that we believe falls within the broad histopathologic spectrum of keratoameloblastoma. We review the key clinical and histopathologic features of the previously reported cases of keratoameloblastoma and present an additional case that presented as an expansile, radiolucent lesion with internal opacification between the roots of teeth in the left anterior maxillary alveolar ridge of a 45-year-old white male. There is wide variation in the histopathologic appearance of cases reported under the appellation keratoameloblastoma. Our case exhibited a histopathologic feature shared by only 2 of the previously reported cases, notably islands and anastomosing cords of epithelium forming lamellated, pacinian-like stacks of parakeratin that extruded into the collagenous tumor stroma without eliciting a foreign body response. Due to the small number of reported cases, we are unable to accurately assess whether the biologic behavior of keratoameloblastoma differs from other histologic types of ameloblastoma. 相似文献
196.
Parish P Sedghizadeh Derek Wong Charles F Shuler Vincent Linz John R Kalmar Carl M Allen 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,104(2):e30-e34
The calcifying epithelial odontogenic tumor (CEOT), or Pindborg tumor, is a rare and benign odontogenic neoplasm that affects the jaw. The most common manifestation of CEOT is a unifocal or localized lesion of the involved jaw, which may appear clinically as a hard tissue swelling and radiographically as a mixed radiolucent-radiopaque mass. In this article, we present a unique case of CEOT affecting multiple sites in the maxilla and mandible of a 51-year-old white man. Though biopsy samples from all involved sites revealed similar histopathologic features consistent with CEOT, the fact that there was a multifocal presentation is an unusual phenomenon for CEOT and has never been reported. Multifocal odontogenic lesions are not typical but have been observed in conditions associated with known genetic mutations. For example, multiple odontogenic keratocysts are the most common feature of the inherited condition known as nevoid basal cell carcinoma syndrome. This case, however, is the first one to demonstrate that there may be a multifocal variant of CEOT that has not been previously recognized. 相似文献
197.
Elizabeth R Seaquist Wei Chen Luke E Benedict Kamil Ugurbil Jae-Hwan Kwag Xiao-Hong Zhu Charles A Nelson 《Journal of cerebral blood flow and metabolism》2007,27(1):154-160
Functional magnetic resonance imaging (fMRI) based on blood oxygen level-dependent (BOLD) contrast has become an invaluable tool in the assessment of in vivo neuronal activation. Quantification of the BOLD response is determined by the hemodynamic and metabolic changes that occur in response to brain stimulation. However, these changes may vary by changes in insulin, a hormone known to be vasoactive in some tissues. To determine if insulin has an effect on fMRI, we measured the BOLD response to a visual stimulus in five normal volunteers in which insulin was first suppressed and then brought to a high physiological concentration. In addition, we also examined the effect of insulin on activation of the visual cortex as measured by the visual-evoked potential (VEP). We found that the BOLD response measured in the presence of insulin (serum insulin=236+/-29 pmol/L) was significantly lower (P<0.001) than that measured in its absence (serum insulin=8+/-2 pmol/L). Insulin was without effect on P100 amplitude or latency acquired in the presence or absence of insulin in 28 subjects using the same stimulus as that used for the fMRI experiments. Our observations suggest that insulin may have effects on cerebral blood flow and/or metabolism that affect the BOLD signal that are independent of its effects on neuronal activation identified by event related potentials (ERP). These findings highlight the complexity that must be considered when interpreting differences in fMRI responses between groups of subjects that differ in insulin concentration and/or insulin sensitivity. 相似文献
198.
The techniques for revascularization in the neurocranium, skull base, and neck continue to evolve at an exciting pace. In this body of literature, however, techniques for harvesting radial artery and saphenous vein grafts are mainly reported using traditional open techniques. Minimally invasive procedures are fast becoming an alternative to open techniques in many fields and have the potential to become the standard of care. The cardiovascular literature is replete with reports of endoscopically harvested vascular grafts. This article reviews both methods, since the current state of the art involves knowledge of open and endoscopic harvesting techniques. 相似文献
199.
Maurizio Fava Michael E Thase Charles DeBattista Karl Doghramji Sanjay Arora Rod J Hughes 《Annals of clinical psychiatry》2007,19(3):153-159
BACKGROUND: Partial response, no response, or residual symptoms following antidepressant therapy is common in clinical psychiatry. This study evaluated modafinil in patients with major depressive disorder (MDD) who were partial responders to adequate selective serotonin reuptake inhibitor (SSRI) therapy and excessive sleepiness and fatigue. METHODS: This retrospective analysis pooled the data of patients (18-65 yrs) who participated in two randomized, double-blind, placebo-controlled studies of modafinil (6-week, flexible-dose study of 100-400 mg/day or 8-week, fixed-dose study of 200 mg/day) plus SSRI therapy. Patients (n=348) met criteria for several residual symptoms (Epworth Sleepiness Scale [ESS] score>or=10; 17-item Hamilton Depression Scale [HAM-D] score between 4 and 25; and Fatigue Severity Scale [FSS] score>or=4). RESULTS: Compared to placebo, modafinil augmentation rapidly (within 1 week) and significantly improved overall clinical condition (Clinical Global Impression-Improvement), wakefulness (ESS), depressive symptoms (17-item HAM-D), and fatigue (FSS) (p<.01 for all). At final visit, patients receiving modafinil augmentation experienced statistically significant improvements in overall clinical condition, wakefulness, and depressive symptoms. Modafinil was well tolerated in combination with SSRI. CONCLUSIONS: Results of this pooled analysis provide further evidence suggesting that modafinil is an effective and well-tolerated augmentation therapy for partial responders to SSRI therapy, particularly when patients continue to experience fatigue and excessive sleepiness. 相似文献
200.
- 1.
- 1. The severe burn case carries a responsibility not only for the attending surgeon, but for all individuals participating in the treatment. Close attention to details of therapy is essential. 相似文献