全文获取类型
收费全文 | 3377篇 |
免费 | 387篇 |
国内免费 | 43篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 161篇 |
妇产科学 | 70篇 |
基础医学 | 288篇 |
口腔科学 | 39篇 |
临床医学 | 383篇 |
内科学 | 924篇 |
皮肤病学 | 180篇 |
神经病学 | 330篇 |
特种医学 | 333篇 |
外科学 | 347篇 |
综合类 | 37篇 |
预防医学 | 177篇 |
眼科学 | 29篇 |
药学 | 219篇 |
中国医学 | 8篇 |
肿瘤学 | 256篇 |
出版年
2023年 | 59篇 |
2022年 | 38篇 |
2021年 | 62篇 |
2020年 | 112篇 |
2019年 | 45篇 |
2018年 | 126篇 |
2017年 | 105篇 |
2016年 | 104篇 |
2015年 | 111篇 |
2014年 | 145篇 |
2013年 | 171篇 |
2012年 | 121篇 |
2011年 | 137篇 |
2010年 | 124篇 |
2009年 | 157篇 |
2008年 | 110篇 |
2007年 | 116篇 |
2006年 | 127篇 |
2005年 | 116篇 |
2004年 | 87篇 |
2003年 | 83篇 |
2002年 | 73篇 |
2001年 | 91篇 |
2000年 | 71篇 |
1999年 | 73篇 |
1998年 | 97篇 |
1997年 | 110篇 |
1996年 | 98篇 |
1995年 | 74篇 |
1994年 | 67篇 |
1993年 | 64篇 |
1992年 | 62篇 |
1991年 | 38篇 |
1990年 | 72篇 |
1989年 | 86篇 |
1988年 | 68篇 |
1987年 | 51篇 |
1986年 | 34篇 |
1985年 | 32篇 |
1984年 | 25篇 |
1983年 | 20篇 |
1982年 | 17篇 |
1981年 | 16篇 |
1980年 | 16篇 |
1979年 | 16篇 |
1978年 | 19篇 |
1977年 | 16篇 |
1971年 | 16篇 |
1970年 | 12篇 |
1967年 | 11篇 |
排序方式: 共有3807条查询结果,搜索用时 15 毫秒
61.
62.
Celi F Bini V Papi F Santilli E Ferretti A Mencacci M Berioli MG De Giorgi G Falorni A 《Clinical endocrinology》2005,63(2):139-145
OBJECTIVE: To study the circulating levels of two gut-derived peptides in children with type 1 (insulin-dependent) diabetes mellitus (IDDM). RESEARCH DESIGN AND METHODS: Plasma levels of ghrelin, both total ghrelin (TG) and the acylated form (AG), and galanin and their relationships with insulin dosage, metabolic control, IGFBP-1, body mass and pubertal development were evaluated in 91 children, aged 11.1 +/- 2.7 years, affected by IDDM and treated with insulin. Ninety-one healthy children were selected as controls. RESULTS: Body mass index (BMI)-adjusted levels of both forms of ghrelin were reduced in IDDM compared with healthy subjects, with greater values in prepubertal than pubertal IDDM subjects. A negative association was found between AG and fasting insulin serum levels and insulin resistance [measured by using the homeostasis model assessment of insulin resistance (HOMA IR)] among the healthy children. IDDM children showed a negative association of their plasma ghrelin (both acylated and total) with daily insulin dosage, and the three adiposity indices (BMI, skinfold thickness and percentage fat mass). IGFBP-1 levels were higher among the IDDM children without any association with ghrelin serum values. BMI-adjusted plasma levels of galanin were higher among IDDM compared to healthy subjects, irrespective of sex or pubertal development. Greater values for galanin were found among pubertal than prepubertal subjects in both groups without any significant differences between the genders. A positive association was found between galanin and BMI in both groups and between galanin and haemoglobin A1c (HbA1c) among the IDDM children. No relationship existed between either galanin and fasting serum insulin among the healthy subjects or galanin and both insulin dosage or duration of treatment among the IDDM subjects. CONCLUSIONS: The associations found between both ghrelin and galanin with adiposity indices could be considered as an indirect signal of involvement of the two peptides in the development of the nutritional status of the IDDM adolescents. The reduction in both forms of ghrelin could be involved in the development of the body mass increase of IDDM subjects with opposite effects, either influencing insulin sensitivity or exerting a compensatory restraint of feeding. 相似文献
63.
Fabio Fabbian Alfredo De Giorgi Marco Pala Stefano Volpato Francesco Portaluppi Giovanni Zuliani Roberto Manfredini 《Disease markers》2013,35(6):735-740
Background. We investigated the relationship between NT-pro-BNP, glomerular filtration rate (GFR), and all-cause mortality rates in a cohort of older people discharged from an internal medicine unit after admission for dyspnoea. Patients and Methods. NT-pro-BNP was evaluated in serum samples of 134 patients aged 80 ± 6 years who presented to a single academic centre with worsening dyspnoea. History data and anthropometric, clinical, and biochemical parameters including GFR were collected at the time of admission. 119 out of 134 were discharged alive from hospital and were included in the follow-up of 779 ± 370 days. Results. 35 out of 119 subjects died after a follow-up of 266 ± 251 days. Cox proportional hazards model showed that GFR and Ln (NT-pro-BNP) were predictors for all-cause mortality with estimated hazard ratios of 0.969 (95% confidence interval: 0.950–0.988; P = 0.001) and 2.360 (95% confidence interval: 1.208–4.610; P = 0.012), respectively. Patients characterized by high NT-pro-BNP levels and GFR ≥ 60 mL/min/1.73 m2 showed a dramatic reduction in survival duration compared with the groups with different combinations of the two variables (P = 0.008). Conclusions. In the elderly, NT-pro-BNP and GFR are predictors of all-cause mortality after admission because of dyspnoea. Since the fact that subjects with high NT-pro-BNP and GFR ≥ 60 mL/min/1.73 m2 exhibited a reduced survival, high admission NT-pro-BNP suggests future negative outcome. 相似文献
64.
65.
DM Clarkson 《Journal of medical engineering & technology》2013,37(3):125-131
An overview is provided of the scope and application of IEC TR 60825-9 in determination of hazards of non coherent optical radiation sources. Specific areas reviewed in detail include those relating to hazards of ultraviolet radiation, retinal thermal hazard and blue light photochemical hazard. The effect of spectral temperature on relative risk relating to retinal thermal hazard and blue light photochemical hazard are outlined. Assessment of risk factors of these hazards was determined using a range of measurement devices including spectral radiometer, broad band power meter and a locally developed device for determination of pulse profile of pulsed light sources. 相似文献
66.
Zaza Demetrashvili Giorgi Kenchadze Irakli Pipia Eka Ekaladze George Kamkamidze 《International surgery》2015,100(6):1021-1025
The aim of our study is to compare the results of emergency surgery versus conservative treatment with interval surgery in patients diagnosed with appendiceal mass and abscess. A retrospective review of 48 patients with appendiceal mass and abscess treated from January 2002 to January 2013 at General Surgery Department of Kipshidze Central University Hospital was performed. Patients with emergency surgery were compared to patients treated by nonoperative management with interval surgery. Demographics, clinical profile, and operative outcomes were studied. The emergency surgery group included 25 patients, and the interval surgery group included 23 patients. The clinical characteristics of the emergency surgery and interval surgery groups were not statistically different. In the emergency surgery group, an open appendectomy was performed on 17 patients, and colonic resections (ileocecectomy or right hemicolectomy) were performed on 8 patients. In the interval surgery group, an open appendectomy was performed on 21 patients, and colonic resections were performed on 2 patients. There were no statistical differences in types of surgery, postoperative complications, operation time without colonic resections, and postoperative hospitalization period among these 2 groups. Operation time with colonic resections was of greater duration in the emergency surgery group than in the interval surgery group (P = 0.04). Both treatment methods for appendiceal mass and abscess have the same results. The surgeon must consider clinical symptoms and results of investigations in each particular case when choosing an appropriate treatment method. Prospective randomized controlled trials are required for comparing the results of all 3 treatment methods of appendiceal mass.Key words: Appendicitis, Mass, Abscess, Appendectomy, Ileocecectomy, Right hemicolectomyAcute appendicitis is one of the most frequent acute surgical pathologies. The inflammation in acute appendicitis may sometimes be fixed by the patient''s own defense mechanisms, by the formation of an inflammatory mass (an appendiceal phlegmon) or a circumscribed abscess (an appendiceal abscess), often presenting as a palpable mass days following the onset of symptoms. This complication occurs in 2 to 7% of all cases of appendicitis.1,2Management of appendiceal mass and abscess is either operative or conservative. More evidence is needed to identify which method is superior.1 Immediate appendectomy may be technically demanding because of the distorted anatomy and difficulties in closing the appendiceal stump due to the inflamed tissues. According to the aforementioned, the operation could be finished with colonic resections (ileocecectomy or right hemicolectomy).2–4Conservative management with interval appendectomy has traditionally remained the gold standard management. The need for interval appendectomy after a successful nonsurgical treatment has recently been questioned as the risk of recurrence is relatively small.5–7 After successful nonsurgical treatment of an appendiceal mass, the true diagnosis is uncertain in some cases and underlying diagnosis of cancer or Crohn''s disease (CD) may be delayed.1,8,9The aim of our study is to compare the results of emergency surgery versus conservative treatment followed by elective surgery in patients diagnosed with appendiceal mass and abscess. 相似文献
67.
Platelet concentrates were prepared at twice the normal concentration and stored at room temperature for 7 days in either standard bags (controls) or bags to which 1 or 2 g of Amberlite resin beads charged with dibasic phosphate had been added. The resin beads served as a buffer system by providing a "slow release" form of phosphate ions as well as by binding CO2 produced during platelet metabolism. Control platelets demonstrated rapid falls in pH, ATP content, morphology score, and thrombin-induced nucleotide release after 24 hr of storage with a fall in pH to less than 6.0 by day 3. Profound ultrastructural changes and a rise in pO2, suggesting loss of platelet viability, accompanied these changes. In contrast, the resin-stored platelets remained near normal after 24 hr of storage, with preservation of discoid morphology, 95% of ATP levels, excellent ultrastructural appearance, and evidence of continued oxygen consumption after 3 days of storage. Even after 7 days of storage, ATP levels remained greater than 50% of baseline and ultrastructurally intact platelets were seen. In the 1-g resin bags the pH remained at baseline levels (6.9-7.0), while there was a rise in pH in the 2-g resin bags. These results demonstrate the beneficial effects of maintaining a higher pH during platelet storage and provide a new approach to studying the metabolic changes that occur during longer term storage. 相似文献
68.
New abnormalities in the morphology, cell surface receptors, and electrolyte metabolism of In(Lu) erythrocytes 总被引:1,自引:0,他引:1
The In(Lu) phenotype is inherited as an autosomal dominant trait and is characterized by suppression of the Lutheran, P1, i, and Aua erythrocyte blood group antigens. We have developed a monoclonal antibody (L21) that strongly agglutinates all erythrocytes except In(Lu), and we have identified eight In(Lu) individuals among 42,000 blood donors tested. Studies of two families confirmed the dominant mode of inheritance and revealed several new features of this phenotype. The erythrocytes of all five affected individuals from the two families exhibited diminished hemagglutination by the lectin concanavalin A, although they reacted normally with several other lectins. The erythrocytes of two affected individuals in one family exhibited marked acanthocytosis. The erythrocytes of the proposita of the other family exhibited a mild degree of poikilocytosis, but the cells of the other two affected individuals in this family had normal morphology. The osmotic fragility of fresh In(Lu) erythrocytes was normal, but after incubation for 24 hours at 37 degrees C in plasma the In(Lu) cells exhibited a marked increase in resistance to osmotic lysis. During the incubation period the erythrocytes lost K+ and their total cation content was diminished. These data indicate that in addition to the suppression of blood group antigens noted previously, the In(Lu) phenotype includes a variety of morphological abnormalities and a defect in electrolyte metabolism. The use of L21 and similar monoclonal antibodies provides a more sensitive means of detecting In(Lu) erythrocytes than typing with human anti-Lub antisera. 相似文献
69.
Yang OO Boscardin WJ Matud J Hausner MA Hultin LE Hultin PM Shih R Ferbas J Siegal FP Shodell M Shearer GM Grene E Carrington M O'Brien S Price CB Detels R Jamieson BD Giorgi JV 《AIDS research and human retroviruses》2002,18(14):1051-1065
The host immune factors that determine susceptibility to HIV-1 infection are poorly understood. We compared multiple immunologic parameters in three groups of HIV-1-seronegative men: 14 highly exposed (HR10), 7 previously reported possibly to have sustained transient infection (PTI), and a control group of 14 low risk blood bank donors (BB). Virus-specific cellular immune assays were performed for CD4(+) T helper cell responses, CD8(+) cytotoxic T lymphocyte activity, CD8(+) cell chemokine release, and CD8(+) cell-derived antiviral soluble factor activity. General immune parameters evaluated included CCR5 genotype and phenotype, interferon alpha production by PBMCs, leukocyte subset analysis, and detailed T lymphocyte phenotyping. Comparisons revealed no detectable group-specific differences in measures of virus-specific immunity. However, the HR10 group differed from the BB group in several general immune parameters, having higher absolute monocyte counts, higher absolute CD8(+) T cell counts and percentages, lower naive and higher terminal effector CD8(+) cells, and lower levels of CD28(+)CD8(+) cells. These changes were not associated with seropositivity for other chronic viral infections. The PTI men appeared to have normal levels of monocytes and slightly elevated levels of CD8(+) T cells (also with increased effector and decreased naive cells). Although we cannot entirely exclude the contribution of other chronic viral infections, these findings suggest that long-lived systemic cellular antiviral immunity as detected by our assays is not a common mechanism for resistance to infection, and that resistance may be multifactorial. General immune parameters reflected by CD8(+) T cell levels and activation, and monocyte concentrations may affect the risk of infection with HIV-1, and/or serve as markers of exposure. 相似文献
70.
Recurrent Spontaneous Paresthesia in the Upper Limb Could Be Due to Migraine: A Case Series 下载免费PDF全文
Sanjay Prakash DM Chaturbhuj Rathore DM Prayag Makwana MD Mitali Rathod MD 《Headache》2015,55(8):1143-1147
Transient neurologic dysfunction is a characteristic feature of migraine. About 20% of migraineurs may experience various symptoms in the absence of any headache at one time or another. Visual auras are the most common auras of migraine, and migraine is considered as the most common cause of transient vision loss in young patients. Sensory auras are the second most common migrainous auras. However, the literature is silent for isolated sensory aura as a migraine equivalent. Herein we report 14 patients with recurrent episodic paresthesia in the limbs and other body parts. All patients fulfilled the diagnostic criteria of “typical aura without headache” of ICHD‐3β. All patients were subjected to various investigations to rule out secondary causes. Ten patients received antimigraine drugs and all showed a positive response to therapy. Recurrent spontaneous paresthesia is quite common in the general population and many patients remain undiagnosed. We speculate that a subset of patients might be related to migrainous sensory auras. 相似文献