全文获取类型
收费全文 | 15808篇 |
免费 | 1346篇 |
国内免费 | 67篇 |
专业分类
耳鼻咽喉 | 205篇 |
儿科学 | 354篇 |
妇产科学 | 233篇 |
基础医学 | 2053篇 |
口腔科学 | 216篇 |
临床医学 | 1736篇 |
内科学 | 3418篇 |
皮肤病学 | 386篇 |
神经病学 | 953篇 |
特种医学 | 655篇 |
外科学 | 2611篇 |
综合类 | 115篇 |
现状与发展 | 1篇 |
一般理论 | 4篇 |
预防医学 | 1339篇 |
眼科学 | 517篇 |
药学 | 1142篇 |
中国医学 | 86篇 |
肿瘤学 | 1197篇 |
出版年
2024年 | 16篇 |
2023年 | 181篇 |
2022年 | 447篇 |
2021年 | 864篇 |
2020年 | 455篇 |
2019年 | 559篇 |
2018年 | 649篇 |
2017年 | 426篇 |
2016年 | 510篇 |
2015年 | 524篇 |
2014年 | 661篇 |
2013年 | 718篇 |
2012年 | 1141篇 |
2011年 | 1097篇 |
2010年 | 657篇 |
2009年 | 527篇 |
2008年 | 909篇 |
2007年 | 890篇 |
2006年 | 759篇 |
2005年 | 708篇 |
2004年 | 630篇 |
2003年 | 545篇 |
2002年 | 502篇 |
2001年 | 498篇 |
2000年 | 456篇 |
1999年 | 374篇 |
1998年 | 123篇 |
1997年 | 101篇 |
1996年 | 91篇 |
1995年 | 78篇 |
1994年 | 69篇 |
1993年 | 58篇 |
1992年 | 150篇 |
1991年 | 107篇 |
1990年 | 120篇 |
1989年 | 107篇 |
1988年 | 93篇 |
1987年 | 85篇 |
1986年 | 66篇 |
1985年 | 55篇 |
1984年 | 48篇 |
1983年 | 34篇 |
1982年 | 21篇 |
1981年 | 11篇 |
1980年 | 17篇 |
1979年 | 16篇 |
1978年 | 6篇 |
1977年 | 10篇 |
1976年 | 10篇 |
1975年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
J Alexandre M Gross-Goupil B Falissard M-L Nguyen J-M Gornet J-L Misset F Goldwasser 《Annals of oncology》2003,14(1):36-41
BACKGROUND: The toxicity outcome of cancer patients receiving chemotherapy is difficult to predict. In this study the influence of malnutrition and inflammation on acute haematological toxicity was investigated. PATIENTS AND METHODS: Between January 1999 and January 2000, 48 consecutive cancer patients experienced severe haematological toxicity (SHT), either neutropenic fever or severe thrombocytopenia, following various chemotherapy regimens. Their baseline characteristics were compared with those of 59 control patients. Previous chemotherapy regimens, type of chemotherapy, performance status (PS), calculated creatinine clearance, bilirubin, C-reactive protein (1), alpha-1 acid glycoprotein (2), albumin (3), pre-albumin (4) and the nutritional and inflammatory status (NIS) ratio [NIS = (1 x 2)/(3 x 4)] were studied. Statistical analysis was carried out using either a t-test or a chi-square test. A receiver operating characteristic (ROC) curve determined the cut-off value for NIS. RESULTS: Patients experiencing SHT had a higher PS (P <0.001), inflammatory serum protein levels (P <0.001) and NIS ratio (P <0.0001), but lower haemoglobin (P <0.05) and serum-albumin levels (P <0.0001). Using a cut-off of 0 or 1 for PS and 1 for NIS, sensitivity was 98%, 43% and 89%; specificity was 38%, 90% and 66%, respectively. In 37 patients treated with topotecan as single agent, the determinants for SHT were PS (P <0.0001) and NIS (P <0.0001). CONCLUSIONS: Altered nutritional and inflammatory status correlates with increased risk of severe haematological toxicity following anticancer chemotherapy. 相似文献
83.
Quinten M. VanderWerf Dan J. Castro Richard D. Nguyen Marcos B. Paiva Kuo H. Chao Mario E. Santillanes Romaine E. Saxton 《The Laryngoscope》1997,107(3):316-320
Neutral red (NR) is a cationic, nontoxic vital dye employed as a histologic stain for proliferating cells; it has been used clinically for photodynamic treatment of herpes simplex virus lesions. NR is selectively taken up and concentrated by mitotic cells, an important characteristic for more effective antineoplastic agents. In the present study, UCLA-SO-P3 human squamous carcinoma cells displayed minimal toxicity when incubated with up to 50 μg/ml NR in the absence of light. However, cells incubated with greater than 0.5μg/ml NR followed by exposure to KTP laser light at 532 nm exhibited nearly 100% tumor cell death. The degree of cell toxicity was proportional to NR dose and laser light fluence. This study demonstrates that NR is an excellent cancer cell photosensitizer in vitro, and, after adding additional in vivo preclinical testing, may prove to be a useful agent in photodynamic destruction of head and neck tumors. 相似文献
84.
85.
Bachoud-Lévi A Bourdet C Brugières P Nguyen JP Grandmougin T Haddad B Jény R Bartolomeo P Boissé MF Barba GD Degos JD Ergis AM Lefaucheur JP Lisovoski F Pailhous E Rémy P Palfi S Defer GL Cesaro P Hantraye P Peschanski M 《Experimental neurology》2000,161(1):194-202
This study describes issues related to the safety and tolerability of fetal striatal neural allografts as assessed in five patients with Huntington's disease. Huntington's disease (HD) is characterized by motor, cognitive, and behavioral disturbances. The latter include psychological disturbances and, as a consequence, we took particular care to analyze behavioral changes, in addition to the usual "safety" follow-up. We conducted multidisciplinary follow-up at least 2 years before and 1 year after grafting. Psychological care extended to close relatives. The grafting procedure itself was altogether safe and uneventful, and there were no apparent clinical deleterious effects for 1 year. The immunosuppressive treatment, however, was complicated by various problems (irregular compliance, errors of handling, side effects). Direct psychological consequences of the transplantation procedure were rare and not worrisome, although mood alteration requiring treatment was observed in one patient. Indirectly, however, the procedure required patients and relatives to accept constraints that tended to complicate familial situations already marred by aggressivity and depression. All patients and close relatives expressed major expectations, in spite of our strong and repeated cautioning. It is clearly important to be aware of these particular conditions since they may eventually translate into psychological difficulties in coping with the long-term clinical outcome of the procedure, if not beneficial. Despite an overall good tolerance, therefore, this follow-up calls for caution regarding the involvement of HD patients in experimental surgical protocols. 相似文献
86.
Adult rats who have undergone neonatal 192 IgG-saporin induced lesions of forebrain acetylcholine (ACH) neurons are normal on many behavioral tasks. In this study we determined whether ectopic hippocampal ingrowths, a documented consequence of these neonatal cholinergic lesions, functionally compensate for ACH denervation in these rats. Neonatal rats underwent systemic 6-hydroxydopamine (6-OHDA) injections on postnatal days (PND) 1-3 to prevent the ingrowths, and/or intraventricular 192 IgG-saporin injections on PND 7. The 192 IgG-saporin profoundly reduced basal forebrain p75 neurotrophin receptor (p75(NTR)) immunoreactive (IR) neurons. The 6-OHDA treatment abolished hippocampal and cortical dopamine-beta-hydroxylase (DBH) IR terminals, indicating the absence of normal norepinephrine (NE) innervation. Ectopic DBH IR and p75(NTR) IR varicosities which occurred in the hippocampus of 192 IgG-saporin treated rats were also eliminated by 6-OHDA treatment. Behavioral testing in adulthood indicated no effect of the treatments on the Morris water maze. 192 IgG-saporin treatment caused perseveration during delayed spatial alternation (DSA) and increased working but not reference memory errors on the radial arm maze (RAM). The 6-OHDA plus 192 IgG-saporin treated rats did not differ from the 192 IgG-saporin only rats on any task. These results indicate that ectopic hippocampal NE ingrowths do not functionally compensate for neonatal ACH lesions. Neonatal forebrain ACH lesion impairs working memory on the RAM but the absence of an effect on DSA contraindicates a basic dysfunction of short term memory. Despite severe combined neonatal loss of forebrain ACH and NE innervation, behavior is remarkably intact. 相似文献
87.
Prognostic variables in male breast cancer 总被引:5,自引:0,他引:5
The prognostic role of ploidy status, S phase fraction, estrogen and progesterone receptor status, and the expression of p53 and erbB-2 protein in male breast carcinoma (MBC) remains controversial. The primary objective of this study was to determine which of the common prognostic factors for female breast cancer predict prognosis in MBC. A secondary objective was to assess the impact of comorbid illnesses on survival. A retrospective review of demographic data, surgical treatment, pathological staging, adjuvant treatment and follow-up was completed for 16 patients with MBC (1 intraductal and 15 invasive). Formalin-fixed, paraffin-embedded tissue was processed for ploidy, S phase fraction, and immunohistochemical detection of estrogen and progesterone receptors plus expression of p53 and erbB-2 protein. Six of 15 patients with infiltrating ductal carcinoma are currently alive without evidence of disease and a median survival of 61 months. Nine patients died after a median survival of 52 months, with 6 patients having no evidence of recurrent breast cancer. Two of 3 deaths secondary to advanced breast cancer occurred in patients who initially presented with T4 lesions and were staged IIIB. Two of 15 tumors were erbB-2 positive, whereas only 1 tested weakly positive for p53 protein. We observed that MBCs express erbB-2 and p53 proteins infrequently. Neither ploidy status, S phase fraction, nor erbB-2/p53 status provided any apparent improvement in establishing prognosis beyond routine pathological staging. Advanced TNM stage was associated with diminished survival. The majority of MBCs express estrogen and progesterone receptors. Survivals in MBC were reduced in association with comorbid medical conditions. 相似文献
88.
89.
Some studies have suggested that noradrenergic activity may decrease with age in depressed patients. Pupil size is regulated by a balance between norepinephrine and acetylcholine. The present study compares pupil size in 10 unmedicated patients with unipolar depression (296. 3) and in 16 normal controls. Pupil size after dilation with tropicamide, a cholinergic antagonist, was inversely related to age in the patients (r=-0.87), but did not diminish with age in controls. The results suggest that pupil size may provide an index of diminished noradrenergic function with age in patients with major depression. 相似文献
90.
Beschorner R Schluesener HJ Nguyen TD Magdolen V Luther T Pedal I Mattern R Meyermann R Schwab JM 《Neuropathology and applied neurobiology》2000,26(6):522-527
Urokinase-type plasminogen activator receptor (uPAR/CD87) together with its ligand, urokinase-type plasminogen activator (uPA), constitutes a proteolytic system associated with tissue remodelling and leucocyte infiltration. uPAR is a member of the glycosyl phosphatidyl inositol (GPI) anchored protein family. The functional role of uPAR comprises fibrinolysis by conversion of plasminogen to plasmin. In addition, uPAR promotes cell adhesion, migration, proliferation, re-organization of the actin cytoskeleton, and angiogenesis. Furthermore, uPAR is involved in prevention of scar formation and is chemoattractant to macrophages and leucocytes. In order to investigate the pathophysiological role of uPAR following human CNS injury we examined necrotic brain lesions resulting from traumatic brain injury (TBI; n = 28) and focal cerebral infarctions (FCI; n = 17) by immunohistochemistry. Numbers of uPAR+ cells and uPAR+ blood vessels were counted. Following brain damage, uPAR+ cells increased significantly within 12 h, reached a maximum after 3-4 days and remained elevated until later stages. uPAR was expressed by infiltrating granulocytes, activated microglia/macrophages and endothelial cells. Numbers of uPAR+ vessels increased in parallel subsiding earlier following FCI than post TBI. The restricted, lesion-associated accumulation of uPAR+ cells in the brain parenchyma and upregulated expression by endothelial cells suggests a crucial role for the influx of inflammatory cells and blood-brain barrier (BBB) disturbance. Through a failure in BBB function, uPAR participates in formation of brain oedema and thus contributes to secondary brain damage. In conclusion, the study defines the localization, kinetic course and cellular source of uPAR as a potential pharmacological target following human TBI and FCI. 相似文献