全文获取类型
收费全文 | 574篇 |
免费 | 36篇 |
国内免费 | 16篇 |
专业分类
儿科学 | 20篇 |
妇产科学 | 9篇 |
基础医学 | 49篇 |
口腔科学 | 13篇 |
临床医学 | 37篇 |
内科学 | 113篇 |
皮肤病学 | 9篇 |
神经病学 | 24篇 |
特种医学 | 147篇 |
外科学 | 141篇 |
综合类 | 7篇 |
预防医学 | 13篇 |
眼科学 | 4篇 |
药学 | 19篇 |
肿瘤学 | 21篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 11篇 |
2020年 | 7篇 |
2019年 | 11篇 |
2018年 | 15篇 |
2017年 | 8篇 |
2016年 | 10篇 |
2015年 | 10篇 |
2014年 | 14篇 |
2013年 | 17篇 |
2012年 | 13篇 |
2011年 | 24篇 |
2010年 | 13篇 |
2009年 | 26篇 |
2008年 | 20篇 |
2007年 | 22篇 |
2006年 | 13篇 |
2005年 | 24篇 |
2004年 | 21篇 |
2003年 | 8篇 |
2002年 | 15篇 |
2001年 | 11篇 |
2000年 | 8篇 |
1999年 | 13篇 |
1998年 | 19篇 |
1997年 | 24篇 |
1996年 | 24篇 |
1995年 | 13篇 |
1994年 | 17篇 |
1993年 | 8篇 |
1992年 | 12篇 |
1991年 | 1篇 |
1990年 | 9篇 |
1989年 | 12篇 |
1988年 | 10篇 |
1987年 | 10篇 |
1986年 | 12篇 |
1985年 | 17篇 |
1984年 | 6篇 |
1983年 | 17篇 |
1982年 | 18篇 |
1981年 | 16篇 |
1980年 | 10篇 |
1979年 | 4篇 |
1978年 | 6篇 |
1977年 | 11篇 |
1976年 | 6篇 |
1975年 | 2篇 |
排序方式: 共有626条查询结果,搜索用时 78 毫秒
1.
2.
3.
Perfluorochemicals as US contrast agents for tumor imaging and hepatosplenography: preliminary clinical results 总被引:3,自引:0,他引:3
Mattrey RF; Strich G; Shelton RE; Gosink BB; Leopold GR; Lee T; Forsythe J 《Radiology》1987,163(2):339-343
In animals, perfluorochemicals (PFCs) are effective ultrasound (US) contrast agents that produce hepatic, splenic, and tumor enhancement. The use of Fluosol-DA 20%, an emulsion of perfluorodecalin and perfluorotripropylamine, was studied in nine non-critically ill patients with cancer who had liver lesions. US studies without Fluosol were compared with studies obtained 24, 48, and 72 hours after Fluosol infusion. Vital signs and extensive laboratory analyses are performed before and after Fluosol infusion. Liver metastases from colonic, pancreatic, and gastric carcinoma exhibited rim or diffuse enhancement after a Fluosol dose of 1.6 g/kg or greater. Fluosol produced echogenic enhancement of the liver and spleen relative to kidney at a dose of 2.4 g/kg, allowing the detection of nonenhancing lesions. In addition, Fluosol at a dose of 1.6 g/kg or greater allowed detection of lesions not seen before contrast medium was administered in three of the seven patients studied. There was a mild increase in the level of serum glutamic oxaloacetic transaminase in two patients, one given 2.4 and the other 3.2 g/kg of Fluosol. Mild and transient allergic reactions without change in vital signs were experienced by two patients. 相似文献
4.
5.
db/db mice exhibit severe wound-healing impairments compared with other murine diabetic strains in a silicone-splinted excisional wound model 总被引:1,自引:0,他引:1
Joseph Michaels VMD ; Samara S. Churgin MD ; Keith M. Blechman MD ; Matthew R. Greives BA ; Shahram Aarabi BA ; Robert D. Galiano MD ; Geoffrey C. Gurtner MD 《Wound repair and regeneration》2007,15(5):665-670
The pathophysiology of diabetic wound healing and the identification of new agents to improve clinical outcomes continue to be areas of intense research. There currently exist more than 10 different murine models of diabetes. The degree to which wound healing is impaired in these different mouse models has never been directly compared. We determined whether differences in wound impairment exist between diabetic models in order to elucidate which model would be the best to evaluate new treatment strategies. Three well-accepted mouse models of diabetes were used in this study: db/db, Akita, and streptozocin (STZ)-induced C57BL/6J. Using an excisional model of wound healing, we demonstrated that db/db mice exhibit severe impairments in wound healing compared with STZ and Akita mice. Excisional wounds in db/db mice show a statistically significant delay in wound closure, decreased granulation tissue formation, decreased wound bed vascularity, and markedly diminished proliferation compared with STZ, Akita, and control mice. There was no difference in the rate of epithelialization of the full-thickness wounds between the diabetic or control mice. Our results suggest that splinted db/db mice may be the most appropriate model for studying diabetic wound-healing interventions as they demonstrate the most significant impairment in wound healing. This study utilized a novel model of wound healing developed in our laboratory that stents wounds open using silicone splints to minimize the effects of wound contraction. As such, it was not possible to directly compare the results of this study with other studies that did not use this wound model. 相似文献
6.
Joseph Michaels th MD ; Michael Dobryansky MD ; Robert D.. Galiano MD ; Kirit A.. Bhatt MD ; Russell Ashinoff MD ; Daniel J. Ceradini MD ; Geoffrey C.. Gurtner MD 《Wound repair and regeneration》2005,13(5):506-512
The prevention of new blood vessel growth is an increasingly attractive strategy to limit tumor growth. However, it remains unclear whether anti-angiogenesis approaches will impair wound healing, a process thought to be angiogenesis dependent. Results of previous studies differ as to whether angiogenesis inhibitors delay wound healing. We evaluated whether endostatin at tumor-inhibiting doses delayed excisional wound closure. C57/BL6J mice were treated with endostatin or phosphate-buffered solution 3 days prior to the creation of two full-thickness wounds on the dorsum. Endostatin was administered daily until wound closure was complete. A third group received endostatin, but also had daily topical vascular endothelial growth factor applied locally to the wound. Wound area was measured daily and the wounds were analyzed for granulation tissue formation, epithelial gap, and wound vascularity. Endostatin-treated mice showed a significant delay in wound healing. Granulation tissue formation and wound vascularity were significantly decreased, but reepithelialization was not effected. Topical vascular endothelial growth factor application to wounds in endostatin-treated mice resulted in increased granulation tissue formation, increased wound vascularity, and wound closure approaching that of control mice. This study shows that the angiogenesis inhibitor endostatin delays wound healing and that topical vascular endothelial growth factor is effective in counteracting this effect. 相似文献
7.
8.
9.
Cellular dysfunction in the diabetic fibroblast: impairment in migration,vascular endothelial growth factor production,and response to hypoxia 总被引:15,自引:0,他引:15 下载免费PDF全文
Lerman OZ Galiano RD Armour M Levine JP Gurtner GC 《The American journal of pathology》2003,163(1):303-312
Although it is known that systemic diseases such as diabetes result in impaired wound healing, the mechanism for this impairment is not understood. Because fibroblasts are essential for wound repair, we compared the in vitro behavior of fibroblasts cultured from diabetic, leptin receptor-deficient (db/db) mice with wild-type fibroblasts from mice of the same genetic background in processes important during tissue repair. Adult diabetic mouse fibroblast migration exhibited a 75% reduction in migration compared to normal fibroblasts (P < 0.001) and was not significantly stimulated by hypoxia (1% O(2)), whereas wild-type fibroblast migration was up-regulated nearly twofold in hypoxic conditions (P < 0.05). Diabetic fibroblasts produced twice the amount of pro-matrix metalloproteinase-9 as normal fibroblasts, as measured by both gelatin zymography and enzyme-linked immunosorbent assay (P < 0.05). Adult diabetic fibroblasts exhibited a sevenfold impairment in vascular endothelial growth factor (VEGF) production (4.5 +/- 1.3 pg/ml versus 34.8 +/- 3.3 pg/ml, P < 0.001) compared to wild-type fibroblasts. Moreover, wild-type fibroblast production of VEGF increased threefold in response to hypoxia, whereas diabetic fibroblast production of VEGF was not up-regulated in hypoxic conditions (P < 0.001). To address the question whether these differences resulted from chronic hyperglycemia or absence of the leptin receptor, fibroblasts were harvested from newborn db/db mice before the onset of diabetes (4 to 5 weeks old). These fibroblasts showed no impairments in VEGF production under basal or hypoxic conditions, confirming that the results from db/db fibroblasts in mature mice resulted from the diabetic state and were not because of alterations in the leptin-leptin receptor axis. Markers of cellular viability including proliferation and senescence were not significantly different between diabetic and wild-type fibroblasts. We conclude that, in vitro, diabetic fibroblasts show selective impairments in discrete cellular processes critical for tissue repair including cellular migration, VEGF production, and the response to hypoxia. The VEGF abnormalities developed concurrently with the onset of hyperglycemia and were not seen in normoglycemic, leptin receptor-deficient db/db mice. These observations support a role for fibroblast dysfunction in the impaired wound healing observed in human diabetics, and also suggest a mechanism for the poor clinical outcomes that occur after ischemic injury in diabetic patients. 相似文献
10.
Dohle GR; Ramos L; Pieters MH; Braat DD; Weber RF 《Human reproduction (Oxford, England)》1998,13(3):620-623
Male genital tract obstructions may result from infections, previous
inguinal and scrotal surgery (vasectomy) and congenital bilateral absence
of the vas deferens (CBAVD). Microsurgery can sometimes be successful in
treating the obstruction. In other cases and in cases of failed surgical
intervention, the patient can be treated by microsurgical or percutaneous
epididymal sperm aspiration (MESA, PESA) or testicular sperm extraction
(TESE) and intracytoplasmic sperm injection (ICSI). We present the results
of 39 ICSI procedures for obstructive azoospermia in 24 couples. The
aetiology of the obstruction was failed microsurgery in 11 patients, CBAVD
in nine and genital infections in four. Sperm retrieval was accomplished
via MESA in four cases, PESA in 18 cases and via TESE in 11 cases. TESE was
only applied when PESA failed to produce enough spermatozoa for
simultaneous ICSI. In six patients, the ICSI procedure was performed with
cryopreserved spermatozoa after an initial PESA procedure. Fertilization
occurred in 47% of the metaphase II oocytes; embryo transfer was performed
in 92% of procedures and resulted in a clinical pregnancy in 13/39
procedures. Ongoing pregnancy was achieved in 10/39 procedures. One
pregnancy was terminated early after prenatal investigation showed a
cytogenetic abnormality (47,XX+18, Edwards syndrome). The other nine
pregnancies resulted in the live birth of 10 children, without any
congenital abnormalities. Epididymal and testicular retrieved spermatozoa
were successfully used for ICSI to treat obstructive azoospermia, and
resulted in an ongoing pregnancy in 10 of 24 couples (41.6%) after 39 ICSI
procedures, a success rate of 25.6% per treatment cycle and of 27.7% per
embryo transfer.
相似文献