全文获取类型
收费全文 | 22796篇 |
免费 | 1989篇 |
国内免费 | 856篇 |
专业分类
耳鼻咽喉 | 43篇 |
儿科学 | 534篇 |
妇产科学 | 226篇 |
基础医学 | 2482篇 |
口腔科学 | 197篇 |
临床医学 | 1924篇 |
内科学 | 4009篇 |
皮肤病学 | 223篇 |
神经病学 | 1734篇 |
特种医学 | 734篇 |
外国民族医学 | 1篇 |
外科学 | 1724篇 |
综合类 | 2831篇 |
现状与发展 | 3篇 |
预防医学 | 1857篇 |
眼科学 | 184篇 |
药学 | 4476篇 |
6篇 | |
中国医学 | 1477篇 |
肿瘤学 | 976篇 |
出版年
2024年 | 71篇 |
2023年 | 407篇 |
2022年 | 603篇 |
2021年 | 1042篇 |
2020年 | 843篇 |
2019年 | 712篇 |
2018年 | 723篇 |
2017年 | 708篇 |
2016年 | 772篇 |
2015年 | 831篇 |
2014年 | 1184篇 |
2013年 | 1683篇 |
2012年 | 1191篇 |
2011年 | 1079篇 |
2010年 | 930篇 |
2009年 | 866篇 |
2008年 | 925篇 |
2007年 | 879篇 |
2006年 | 792篇 |
2005年 | 726篇 |
2004年 | 645篇 |
2003年 | 577篇 |
2002年 | 521篇 |
2001年 | 524篇 |
2000年 | 433篇 |
1999年 | 371篇 |
1998年 | 350篇 |
1997年 | 385篇 |
1996年 | 347篇 |
1995年 | 299篇 |
1994年 | 304篇 |
1993年 | 291篇 |
1992年 | 290篇 |
1991年 | 262篇 |
1990年 | 265篇 |
1989年 | 238篇 |
1988年 | 242篇 |
1987年 | 221篇 |
1986年 | 186篇 |
1985年 | 228篇 |
1984年 | 275篇 |
1983年 | 148篇 |
1982年 | 190篇 |
1981年 | 159篇 |
1980年 | 153篇 |
1979年 | 142篇 |
1978年 | 123篇 |
1977年 | 111篇 |
1976年 | 106篇 |
1975年 | 82篇 |
排序方式: 共有10000条查询结果,搜索用时 265 毫秒
91.
V. P. Mikhailov L. D. Smirnov G. V. Kurygin N. N. Zolotov 《Bulletin of experimental biology and medicine》1992,113(2):175-177
Department of Pathophysiology, Yaroslavl' State Medical Institute. All-Union Research Center for Safety of Biologically Active Substances, Kupavna, Moscow Region. (Presented by Academician of the Academy of Medical Sciences of the USSR A. G. Chuchalin.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 113, No. 2, pp. 139–141, February, 1992. 相似文献
92.
Spermidine/Spermine N-Acetyltransferase, a New Biochemical Marker for Epithelial Proliferation in Rat Bladder 总被引:4,自引:4,他引:0
Isao Matsui-Yuasa Shuzo Otani Yoshihisa Yano Nobuyasu Takada Masa-Aki Shibata Shoji Fukushima 《Cancer science》1992,83(10):1037-1040
We examined the activity of spermidine/spermine N 1 -acetyltransferase (SAT), a rate-limiting enzyme of the biodegradation of polyamines, in N -butyl- N -(4–hydroxybutyI)nitrosamine-induced transitional cell carcinoma (TCC) and melamine-induced papillomatosis of rat bladder, and compared the activity to that of ornithine decarboxylase (ODC). Both activities were higher in both lesions than in control rats. The difference between SAT and ODC activities in cancerous tissue and papillomatosis was not significant. Cells stained for proliferating cell nuclear antigen (PCNA) were abundant in papillomatosis. TCC had areas with much PCNA. The results indicated that an elevation of SAT activity occurs in both reversible and irreversible proliferation of bladder epithelium and could be important in bladder carcinogenesis. 相似文献
93.
K.-W. Jauch 《Der Chirurg》1997,68(6):551-558
Summary. Trauma, operative interventions, infection and other disturbances of homeostasis lead to a uniform reaction of the body,
namely release and activation of hormones and cytokines. Profound alterations of substrate flow result, with mobilization
of energy stores and degradation of structural and functional proteins of vital organs like the gut mucosa. Due to these reactions
the energy demands of the organs are met and energy-consuming synthesis of substrates is indicated. Clinically, hypermetabolism,
hyperglycemia, lipolysis and increased urea production with negative nitrogen balance can be observed. The metabolic reactivity
is reached by an increased substrate cycling. To avoid negative consequences such as organ dysfunction, a rational situation-adapted
substrate supply is warranted as well as reduction of catabolic stimuli and stimulation of anabolic factors. The metabolic
care of the surgical patient is still a basic and important task.
相似文献
94.
Summary The metabolic potency of recombinant human insulin-like growth factor II was studied in anaesthetized adult rats by obtaining dose-response curves for the hypoglycaemic action and for the stimulation of glucose metabolism during euglycaemic clamping. Compared to insulin, about 50 times higher doses of insulin-like growth factor II were required to result in identical in vivo responses, with half-maximally effective serum concentrations for the stimulation of glucose disposal during clamp studies of about 0.8 and 50 pmol/ml, respectively. A similar difference in potency was observed for the dose-dependent stimulatory actions on glucose metabolism in individual target tissues. Half-maximally effective serum concentrations in the range of 0.8 to 3.0 pmol/ml for insulin and of 40 to 70 pmol/ml for insulin-like growth factor II were seen to be required for 2-deoxyglucose uptake, glycogen formation in skeletal muscle and lipogenesis in epididymal fat. Maximal responses were identical with both peptides. These data suggest that in vivo acute metabolic actions of insulin-like growth factor II on carbohydrate metabolism occurred through insulin receptors. 相似文献
95.
胃肠道肿瘤病人围手术期细胞因子及蛋白质代谢的变化 总被引:4,自引:0,他引:4
目的 :探讨胃肠道肿瘤病人手术后肿瘤坏死因子 α (TNF α)、白介素 6 (IL 6 )、白介素 10 (IL 10 )的变化以及与蛋白质代谢的关系。 方法 :用酶联免疫法 (ELISA)检测 19例胃肠道肿瘤根治术病人术前和术后 1、3、5天血清TNF α、IL 6和IL 10水平 ,同时检测蛋白质分解代谢相关指标、2 4h尿中尿素和肌酐排泄量。 结果 :胃肠道肿瘤根治术后病人TNF α呈下降趋势 ,术后第 1天较术前明显下降 (P <0 .0 5 )。IL 6和IL 10术后升高 (P <0 .0 1) ,尤以术后第 1天升高明显。术后 2 4h尿中尿素和肌酐排泄量明显升高。 结论 :胃肠道肿瘤根治术后病人IL 6和IL 10的升高支持手术应激导致的细胞因子释放变化 ,但TNF α呈下降趋势 ,可能与胃肠道肿瘤病人术前TNF α的高表达有关。术后蛋白质分解代谢增加 ,可能与细胞因子IL 6和IL 10的升高有关。 相似文献
96.
97.
M. R. Clements † 《Journal of human nutrition and dietetics》1989,2(2):105-116
A large body of work relating to the occurrence of rickets in UK Asians is reviewed. Several theories of the aetiology of this condition are shown to be untenable: it is not exclusively a function of sunlight deprivation or of darker pigmentation; nor is it simply due to phytate-induced losses of calcium from the gut. Asian rickets, however, is associated with a high consumption of cereals, and experiments with rats have suggested a mechanism. In the absence of adequate vitamin D from sunlight, the low-calcium, high cereal intake of the UK Asian population may induce a state of mild secondary hyperparathyroidism which enhances the destruction of vitamin D and leads to a progressive reduction in vitamin D status and, ultimately, to the development of clinical rickets. 相似文献
98.
Natural history of parathyroid function and calcium metabolism after kidney transplantation: a single-centre study. 总被引:10,自引:4,他引:6
Pieter Evenepoel Kathleen Claes Dirk Kuypers Bart Maes Bert Bammens Yves Vanrenterghem 《Nephrology, dialysis, transplantation》2004,19(5):1281-1287
BACKGROUND: The natural history of parathyroid function after successful renal transplantation (RT) and the factors predisposing to persistent hyperparathyroidism (HPT) are not well established. A better knowledge of these data may be helpful in the development of algorithms for optimal surveillance and treatment of HPT after successful RT. Our aim was to evaluate the post-transplant natural history of parathyroid function and calcium metabolism in patients with a functional renal graft and to identify risk factors for persistent HPT. METHODS: Charts of 1165 allograft kidney recipients transplanted between 1989 and 2000 were reviewed. Patients with an intact parathyroid hormone (iPTH) level available at the time of transplantation were identified. The charts of the latter patients were checked for a variety of demographic and clinical data, and all determinations of the iPTH concentration available since transplantation were recorded. Serum levels of calcium, phosphorus, alkaline phosphatases and creatinine, concurrently determined, were also registered. RESULTS: After an initial fall, iPTH levels showed a slow but steady decline towards the upper normal limit. The prevalence of persistent HPT, defined as an iPTH level > or =2.5 times the upper normal limit or the need for parathyroidectomy following transplantation, remained stable at approximately 17% up to 4 years after transplantation. Patients with persistent HPT had significantly elevated serum levels of iPTH, calcium and phosphorus at the time of RT, and had spent a longer time on dialysis. Post-transplant iPTH levels correlated significantly with transplant kidney function. CONCLUSION: Kidney transplant recipients with a high iPTH and calcium x phosphate product at the time of transplantation are at risk for persistent HPT especially when renal function is suboptimal. Therapy for persistent HPT, if considered, should be initiated 3 months post-transplantation since further spontaneous improvement of parathyroid function thereafter is limited. 相似文献
99.
A. Poobalan L. Aucott W. C. S. Smith A. Avenell R. Jung J. Broom A. M. Grant 《Obesity reviews》2004,5(1):43-50
This paper aims to review the evidence for long‐term effectiveness of weight loss on cholesterol, high‐density lipoprotein (HDL), low‐density lipoprotein (LDL) and triglycerides in overweight/obese people. Current evidence is mostly based on short‐term studies. A systematic review of long‐term lipid outcomes of weight loss in studies published between 1966 and 2001, was conducted. Inclusion criteria included all cohort studies and trials carried out on participants with body mass index of greater than or equal to 28 kg m?2. Studies had at least two weight change measurements and follow‐up of more than 2 years. Thirteen long‐term studies with a follow‐up of more than 2 years were included. Cholesterol has a significant positive linear relationship with weight change (r = 0.89) where change in weight explains about 80% of the cholesterol difference variation (Adj R2 = 0.80). For every 10 kg weight loss a drop of 0.23 mmol L?1 in cholesterol may be expected for a person suffering from obesity or are grossly overweight. Weight loss has long‐term beneficial effects especially on LDL and cholesterol. Weight loss in obese patients should be encouraged and sustained. 相似文献
100.
F. M. Ulivieri L. P. Piodi G. Marotta D. Marchelli C. Commadini L. Parravicini C. Verdoia P. Gerundini 《Journal of orthopaedics and traumatology》2006,7(4):192-194
Osteoprotegerin (OPG) is a protein that inhibits of osteoclastogenesis. The aim this study was to evaluate the response of
serum OPG levels to neridronate treatment in patients with Paget's disease of bone resistant to previous therapy. Nine patients
(4 men) affected by active Paget’s disease of bone (6 polyostotic, 3 monostotic) not responsive to clodronate were studied.
Serum OPG, osteocalcin, total and bone isoenzyme of alkaline phosphatase (AP and BAP, respectively), and urinary deoxypyridinoline
(DPD) were measured before and 5 months after neridronate treatment (100 mg/day, i.v. for two days). A scintigraphic activity
index (SAI) was also calculated before treatment. Mean baseline OPG levels were within normal values and were not significantly
different 5 months after neridronate treatment. In contrast, there were significant reductions in AP (41.9%, p<0.02) and BAP (38.8%, p<0.04). Serum OPG levels correlated with DPD (r=0.925) and SAI (r=0.689). Although OPG is an important regulator of bone metabolism,
in our series of already treated patients it was not a sensitive marker for diagnosing Paget's disease and for monitoring
the response to pharmacological treatment, whereas AP and BAP confirmed their clinical usefulness. This preliminary study
requires confirmation by a study with a larger population. 相似文献