全文获取类型
收费全文 | 53770篇 |
免费 | 3611篇 |
国内免费 | 263篇 |
专业分类
耳鼻咽喉 | 521篇 |
儿科学 | 1920篇 |
妇产科学 | 1372篇 |
基础医学 | 8041篇 |
口腔科学 | 793篇 |
临床医学 | 5172篇 |
内科学 | 12147篇 |
皮肤病学 | 1176篇 |
神经病学 | 5907篇 |
特种医学 | 1125篇 |
外科学 | 4393篇 |
综合类 | 310篇 |
现状与发展 | 1篇 |
一般理论 | 43篇 |
预防医学 | 5045篇 |
眼科学 | 879篇 |
药学 | 4057篇 |
中国医学 | 136篇 |
肿瘤学 | 4606篇 |
出版年
2024年 | 91篇 |
2023年 | 683篇 |
2022年 | 1441篇 |
2021年 | 2428篇 |
2020年 | 1397篇 |
2019年 | 1790篇 |
2018年 | 1973篇 |
2017年 | 1595篇 |
2016年 | 1752篇 |
2015年 | 1903篇 |
2014年 | 2474篇 |
2013年 | 3102篇 |
2012年 | 4569篇 |
2011年 | 4565篇 |
2010年 | 2425篇 |
2009年 | 2075篇 |
2008年 | 3450篇 |
2007年 | 3442篇 |
2006年 | 3109篇 |
2005年 | 2829篇 |
2004年 | 2619篇 |
2003年 | 2335篇 |
2002年 | 2108篇 |
2001年 | 242篇 |
2000年 | 187篇 |
1999年 | 252篇 |
1998年 | 336篇 |
1997年 | 288篇 |
1996年 | 195篇 |
1995年 | 184篇 |
1994年 | 185篇 |
1993年 | 142篇 |
1992年 | 103篇 |
1991年 | 88篇 |
1990年 | 68篇 |
1989年 | 78篇 |
1988年 | 74篇 |
1987年 | 68篇 |
1986年 | 59篇 |
1985年 | 66篇 |
1984年 | 86篇 |
1983年 | 69篇 |
1982年 | 78篇 |
1981年 | 66篇 |
1980年 | 62篇 |
1979年 | 31篇 |
1978年 | 35篇 |
1977年 | 36篇 |
1976年 | 27篇 |
1973年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Roland Schmitt Anna Maria Dittrich David Groneberg Wanja Griethe 《Medizinische Klinik》2002,55(7):484-487
Zusammenfassung Anamnese und Diagnostik: Ein 75-jähriger Patient wies neben unspezifischen anamnestischen Symptomen (Appetitverlust, Merkfähigkeitsstörung und Muskelschwäche) klinisch diskrete Beinödeme, abgeschwächte Muskeleigenreflexe und eine deutliche Gedächtnisstörung auf. Aufgrund einer euvolämischen, laborchemisch hypoosmolaren Hypoatriämie und eines Urinnatriums im Normbereich wurde als Arbeitsdiagnose von einem Syndrom der inadäquaten ADH-Sekretion (SIADH) ausgegangen. Während sich weder in der Anamnese noch in den folgenden Untersuchungen eine dem SIADH zugrunde liegende Pathologie eruieren ließ, ergab sich in den weiteren Laboruntersuchungen der Befund einer ausgeprägten Hypothyreose. Die Hyponatriämie bei Hypothyreose spiegelt eine Komponente der renalen Funktionsstörung bei Schilddrüsenhormonmangel wider. Therapie und Verlauf: Nach Flüssigkeitsrestriktion und Hormonsubstitution erreichte der Patient schnell normale Natriumwerte und zeigte eine deutliche Besserung seiner kognitiven Fähigkeiten. Schlussfolgerung: Als Schlussfolgerung aus dieser Kasuistik wird Zurückhaltung bei der Diagnose eines SIADH empfohlen, bevor nicht eine sorgfältige Untersuchung des Nebennieren- und Schilddrüsenhormonstatus erfolgt ist. Abstract Case History and Diagnosis: A 75-year-old male patient presented with a history of anorexia, muscle weakness, and increasing memory loss. He had mild pedal edema and decreased deep tendon reflexes. As the laboratory tests showed hypoosmolar hyponatremia and urinary sodium within the normal range, a syndrome of inappropriate ADH secretion (SIADH) was presumed. While neither the medical history nor any of the diagnostic procedures revealed any underlying pathology explaining the SIADH, laboratory tests showed significant hypothyroidism. Hypothyroid states are associated with significant changes in renal function, one of which is hypoosmolar hyponatremia. Treatment and Course: Treatment included fluid restriction and hormone substitution and resulted in a quick correction of the hyponatremia and a clear improvement of the patient's cognitive function. Conclusion: It is concluded that the diagnosis of SIADH should only be made after thorough investigation of the adrenal and thyroid hormone status. 相似文献
52.
53.
54.
Giovanni Corrao Antonella Zambon Lorenza Bertù Anna Mauri Valentina Paleari Camillo Rossi Mauro Venegoni 《Drug safety》2006,29(10):889-896
OBJECTIVE: To investigate the association between the use of fluoroquinolone agents and the risk of tendinitis in a large population-based case-control study. METHODS: The study was performed by linking automated health databases from the Region of Lombardia, Italy. Cases were patients aged > or =18 years who had a hospital discharge diagnosis of non-traumatic tendinitis in 2002-3. For each case, up to five controls were randomly selected among those eligible for inclusion in the study. A conditional logistic regression model was used to estimate the odds ratio of tendinitis associated with the current, recent and past use of fluoroquinolones. Odds ratios were adjusted for exposure to other antibacterials and other drugs. RESULTS: 22,194 cases and 104,906 controls met the inclusion criteria. Current use of fluoroquinolones significantly increased the risk of tendon disorders as a whole (odds ratio [OR] = 1.7; 95% CI 1.4, 2.0), tendon rupture (OR = 1.3; 95% CI 1.0, 1.8) and rupture of the Achilles' tendon (OR = 4.1; 95% CI 1.8, 9.6). Concomitant use of corticosteroids and fluoroquinolones increased the risk of both tendon rupture (OR = 3.1; 95% CI 1.5, 6.3) and rupture of the Achilles' tendon (OR = 43.2; 95% CI 5.5, 341.1). DISCUSSION: Evidence that exposure to fluoroquinolones is associated with the sudden occurrence of tendinitis is supported by this large population-based study. We can estimate that a single case of rupture of the Achilles' tendon would occur for every 5958 persons treated with fluoroquinolones (95% CI 2148, 23,085). The corresponding number needed to harm is 979 (95% CI 122, 9172) for patients who concomitantly use corticosteroids and 1638 (95% CI 351, 8843) for those aged >60 years. CONCLUSION: Clinicians should be aware of this adverse effect, and the increased risk for fluoroquinolone-associated tendinitis in elderly patients with corticosteroid use must be considered when these agents are prescribed. 相似文献
55.
Genetic mapping of the chloroquine-resistance locus on Plasmodium falciparum chromosome 7. 总被引:11,自引:2,他引:9 下载免费PDF全文
T E Wellems A Walker-Jonah L J Panton 《Proceedings of the National Academy of Sciences of the United States of America》1991,88(8):3382-3386
The resurgence of malaria in recent decades has been accompanied by the worldwide spread of resistance to chloroquine, a drug once uncontested as the first-line antimalarial agent because of its efficacy and low toxicity. Chloroquine-resistant strains of Plasmodium falciparum counter the drug by expelling it rapidly via an unknown mechanism. In the absence of explicit biochemical knowledge of this efflux mechanism, reverse genetics provides a powerful approach to the molecular basis of chloroquine resistance. Here we report genetic linkage analysis in which 85 restriction fragment length polymorphism markers were used to examine inheritance of the 14 P. falciparum chromosomes in a laboratory cross between a chloroquine-resistant and a chloroquine-sensitive parasite. Inheritance data from 16 independent recombinant progeny show that the rapid efflux, chloroquine-resistant phenotype is governed by a single locus within an approximately 400-kilobase region of chromosome 7. Identification and characterization of genes within this region should lead to an understanding of the chloroquine-resistance mechanism. 相似文献
56.
Grazyna Jasienska Anna Ziomkiewicz Inger Thune Susan F Lipson Peter T Ellison 《European journal of cancer prevention》2006,15(5):439-445
Variation in the risk of breast cancer observed among women and among populations may be explained by variation in lifetime exposure to estrogens. The suppressive effect of exercise on estradiol levels in women is well documented, but it is unknown whether habitual (i.e. typical daily) physical activity has a similar effect. Epidemiological data suggest that physical activity is one of the few modifiable factors capable of reducing the risk of breast cancer in women. We investigated whether variation in the amount of habitual activity corresponds to variation in estradiol levels in women of reproductive age. One hundred and thirty-nine regularly menstruating women 24-37 years of age collected daily saliva samples for one complete menstrual cycle and kept a daily log of physical activity. Saliva samples were analyzed for concentration of estradiol. We observed a negative relationship between habitual physical activity and salivary levels of estradiol. Mean estradiol was 21.1 pmol/l in the low, 17.9 pmol/l in the moderate and 16.6 pmol/l in the high activity group (all pairwise differences were statistically significant at P<0.009). A strong association exists between physical activity and levels of estradiol among women of reproductive age. A modern lifestyle, characterized by reduced physical activity, may therefore contribute to a rise in the levels of estradiol produced during menstrual cycles and thus to higher cumulative lifetime exposure to estradiol, resulting in a higher risk of breast cancer. 相似文献
57.
The research was designed to investigate the moderating effect of some personality traits on subjective distress caused by daily hassles. The traits were internal locus of control, repression, ego strength, and barrier (as studied and defined by S. Fisher). The last two variables were negatively correlated both with the somatic and emotional distress indications and with the frequency of hassles reportED; internal locus of control showed an inverse relationship only with frequency of hassles. The hypothesis is formulated that ego strength and barrier are personality factors influencing not only the outcomes of coping (ie the stress response), but also event appraisal. 相似文献
58.
W D Panton 《Canadian Medical Association journal》1994,150(11):1759-1760
59.
Anna Letícia Soares Marinez de Oliveira Sousa Luci Maria Dusse Ana Paula Salles Moura Fernandes Marcelo Carvalho Lasmar Bethania Alves Novelli Geralda de Fátima Guerra Lages Maria das Gra?as Carvalho 《Blood coagulation & fibrinolysis》2007,18(5):395-399
This study aimed to investigate whether endothelial cells are damaged and to evaluate fibrinolytic system function in patients with type 2 diabetes. For this proposal, plasma levels of von Willebrand factor (an endothelial marker of injury), homocysteine (an inductor of endothelial injury), D-dimer (a marker of coagulation cascade activation) and plasminogen activator inhibitor-1 (a fibrinolysis marker) were measured in individuals with both type 2 diabetes and high blood pressure, with type 2 diabetes, with high blood pressure and in healthy control individuals. No significant differences among groups were observed for von Willebrand factor and homocysteine plasma levels. The type 2 diabetes and high blood pressure group presented a significant difference to the other groups for D-dimer and also presented high values for plasminogen activator inhibitor-1. The high blood pressure group and type 2 diabetes group presented separately higher values of plasminogen activator inhibitor-1 compared with the control group. High levels of D-dimer and plasminogen activator inhibitor-1 in patients with type 2 diabetes and high blood pressure with normoalbuminuria therefore indicate a state of hypercoagulability and hypofibrinolysis, despite no evident microvascular injury supported by normal levels of von Willebrand factor and homocysteine. 相似文献
60.
Alvisa Palese Laura Regattin Francesca Venuti Anna Innocenti Carla Benaglio Laura Cunico Luisa Saiani 《Journal of wound, ostomy, and continence nursing》2007,34(6):649-654
PURPOSE: The purpose of the study was to evaluate the incidence of incontinence pad use among patients admitted to medical wards, the reasons why nurses decide to use an incontinence pad, the extent to which the use of pads is avoidable, and the outcome of inappropriate pad use after discharge from the hospital. METHODS: A prospective cohort study was conducted; patients admitted to medical wards were observed during hospitalization and a 7-day follow-up period after discharge. SUBJECTS AND SETTING: The study was conducted in 2 acute-care units in Northern Italy. All new patients admitted to the units were recruited. RESULTS: At the time of admission to the hospital, in addition to the 120 patients who already used incontinence pads, there was a 34% incidence of new cases (98/286). The most frequent reason why nurses decided to use this aid was incontinence caused by space-time disorientation, followed by limited mobility, incontinence, patient request, nursing shortage, and involuntary urine leakage not perceived by patient. Seventy patients out of 208 used incontinence pads unnecessarily for a total of 544 days. CONCLUSIONS: Decisions about the use of the incontinence pads are not always consistent with research-based or literature-based suggestions. Nurses should develop clinical guidelines or protocols for the appropriate use of incontinence pads. 相似文献