全文获取类型
收费全文 | 25708篇 |
免费 | 1802篇 |
国内免费 | 169篇 |
专业分类
耳鼻咽喉 | 204篇 |
儿科学 | 576篇 |
妇产科学 | 470篇 |
基础医学 | 3690篇 |
口腔科学 | 259篇 |
临床医学 | 2314篇 |
内科学 | 6049篇 |
皮肤病学 | 328篇 |
神经病学 | 2529篇 |
特种医学 | 863篇 |
外国民族医学 | 1篇 |
外科学 | 4770篇 |
综合类 | 160篇 |
一般理论 | 9篇 |
预防医学 | 1574篇 |
眼科学 | 286篇 |
药学 | 1544篇 |
中国医学 | 77篇 |
肿瘤学 | 1976篇 |
出版年
2023年 | 120篇 |
2022年 | 243篇 |
2021年 | 490篇 |
2020年 | 362篇 |
2019年 | 597篇 |
2018年 | 650篇 |
2017年 | 492篇 |
2016年 | 539篇 |
2015年 | 631篇 |
2014年 | 886篇 |
2013年 | 1207篇 |
2012年 | 1819篇 |
2011年 | 1965篇 |
2010年 | 1192篇 |
2009年 | 1124篇 |
2008年 | 1721篇 |
2007年 | 1772篇 |
2006年 | 1652篇 |
2005年 | 1730篇 |
2004年 | 1529篇 |
2003年 | 1555篇 |
2002年 | 1577篇 |
2001年 | 225篇 |
2000年 | 187篇 |
1999年 | 258篇 |
1998年 | 339篇 |
1997年 | 321篇 |
1996年 | 225篇 |
1995年 | 217篇 |
1994年 | 173篇 |
1993年 | 171篇 |
1992年 | 135篇 |
1991年 | 118篇 |
1990年 | 113篇 |
1989年 | 87篇 |
1988年 | 87篇 |
1987年 | 67篇 |
1986年 | 101篇 |
1985年 | 86篇 |
1984年 | 90篇 |
1983年 | 91篇 |
1982年 | 100篇 |
1981年 | 90篇 |
1980年 | 88篇 |
1979年 | 55篇 |
1978年 | 45篇 |
1977年 | 37篇 |
1976年 | 37篇 |
1975年 | 35篇 |
1974年 | 35篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
Edith Hummler Pierre Barker Colleen Talbot Qing Wang Chantal Verdumo Barbara Grubb John Gatzy Michel Burnier Jean-Daniel Horisberger Friedrich Beermann Richard Boucher Bernard C. Rossier 《Proceedings of the National Academy of Sciences of the United States of America》1997,94(21):11710-11715
Aldosterone-dependent epithelial sodium transport in the distal nephron is mediated by the absorption of sodium through the highly selective, amiloride-sensitive epithelial sodium channel (ENaC) made of three homologous subunits (α, β, and γ). In human, autosomal recessive mutations of α, β, or γENaC subunits cause pseudohypoaldosteronism type 1 (PHA-1), a renal salt-wasting syndrome characterized by severe hypovolemia, high plasma aldosterone, hyponatremia, life-threatening hyperkaliemia, and metabolic acidosis. In the mouse, inactivation of αENaC results in failure to clear fetal lung liquid at birth and in early neonatal death, preventing the observation of a PHA-1 renal phenotype. Transgenic expression of αENaC driven by a cytomegalovirus promoter in αENaC(−/−) knockout mice [αENaC(−/−)Tg] rescued the perinatal lethal pulmonary phenotype and partially restored Na+ transport in renal, colonic, and pulmonary epithelia. At days 5–9, however, αENaC(−/−)Tg mice showed clinical features of severe PHA-1 with metabolic acidosis, urinary salt-wasting, growth retardation, and 50% mortality. Adult αENaC(−/−)Tg survivors exhibited a compensated PHA-1 with normal acid/base and electrolyte values but 6-fold elevation of plasma aldosterone compared with wild-type littermate controls. We conclude that partial restoration of ENaC-mediated Na+ absorption in this transgenic mouse results in a mouse model for PHA-1. 相似文献
992.
Lateral diffusion of surface immunoglobulin, Thy-1 antigen, and a lipid probe in lymphocyte plasma membranes 总被引:17,自引:4,他引:17 下载免费PDF全文
Paul Dragsten Pierre Henkart Robert Blumenthal John Weinstein Joseph Schlessinger 《Proceedings of the National Academy of Sciences of the United States of America》1979,76(10):5163-5167
Fluorescence photobleaching recovery was used to measure the lateral diffusion coefficient and mobile fraction of surface immunoglobulin (sIg), Thy-1 antigen, and a lipid probe in the plasma membrane of mouse lymphocytes. The lipid probe (3,3'-dioctadecylindocarbocyanine) had a mean (+/-SD) diffusion coefficient of (1.7 +/- 0.3) x 10(-8) cm(2)/sec, with essentially all of the probe mobile in the membrane. We detected little or no effect on the diffusion of this probe due to the presence of microvilli. Its diffusion was slightly restricted in capped regions. No differences in lipid probe mobility were detected between T and B cells. Fifty to 90% of the detectable sIg and Thy-1 antigen was free to move in the plane of the membrane with diffusion coefficients of approximately 3 x 10(-10) cm(2)/sec; the remainder was immobile. Crosslinking of sIg with anti-Ig antibodies (in the presence of azide to inhibit capping) completely immobilized sIg at high concentrations but failed to do so at low concentrations. Thy-1 antigen could not be immobilized with an IgG rabbit anti-mouse brain reagent without an additional layer of crosslinking antibody. In parallel labelings (in the absence of azide), capping of sIg and Thy-1 antigen was observed only under crosslinking conditions sufficient to immobilize the membrane antigen. Sodium azide, colchicine, and cytochalasin B had no measurable effect on lipid probe, sIg, or Thy-1 diffusion. 相似文献
993.
Ronald Gold Luis Barreto Santiago Ferro John Thippawong Roland Guasparini William Meekison Margaret Russell Elaine Mills Dana Harrison Pierre Lavigne 《The Canadian Journal of Infectious Diseases & Medical Microbiology》2007,18(4):241-248
OBJECTIVE: The safety, immunogenicity and lot consistency of a fully liquid, five-component acellular pertussis combination vaccine, comprised of diphteria, tetanus and acellular pertussis, inactivated polio vaccine, Haemophilus influenzae type b (DTaP-IPV-Hib [Pediacel, sanofi pasteur, Canada]) were assessed and compared with that of Hib vaccine reconstituted with the five-component acellular pertussis combination vaccine (DTaP-IPV//Hib, Pentacel [sanofi pasteur, Canada]). METHODS: Infants were recruited at vaccine study centres in Montreal, Quebec; Simon Fraser Health Region, British Columbia, and southern Alberta after the protocol had been approved by the relevant institutional ethics committees. Written informed consent was obtained from the parents or guardians of all subjects. At two months of age, the infants were randomly assigned to receive one of three consecutive production lots of DTaP-IPV-Hib by intramuscular injection. Reactions to vaccinations were assessed by parental observation and through telephone interviews conducted by study nurses. Blood samples were obtained at two, six, seven, 18 and 19 months of age for measurement of antibodies to vaccine antigens. RESULTS: Most injection site and systemic reactions were mild or moderate, and of brief duration. All infants were protected against tetanus, diphtheria and all three polio serotypes after both primary and booster vaccinations. Antibody responses to pertussis antigens were similar to those observed in Swedish infants, in whom the five-component vaccine was shown to be 85% effective. Proportions of infants with antipolyribosylribitol phosphate antibody of 0.15 mug/mL or greater and 1.0 mug/mL or greater, were 97.9% and 88.9%, respectively, following primary immunization, and 100% and 99% following booster vaccination. Safety and immunogenicity results with both reconstituted and fully liquid combination vaccines were comparable. CONCLUSIONS: The fully liquid combination vaccine was comparable in terms of safety and immunogenicity with the reconstituted combination vaccine. 相似文献
994.
Comparison of the cardiovascular protection by omapatrilat and lisinopril treatments in DOCA-salt hypertension 总被引:2,自引:0,他引:2
Millette E Demeilliers B Wu R Laplante MA El Midaoui A Moreau P Lamontagne D de Champlain J 《Journal of hypertension》2003,21(1):125-135
OBJECTIVE: To compare the cardiovascular protection provided by omapatrilat and lisinopril in an experimental model of hypertension. METHODS: Four-week deoxycorticosterone acetate (DOCA)-salt hypertensive (HT) and age-matched normotensive (NT) rats were treated either with omapatrilat (40 mg/kg per day) or lisinopril (20 mg/kg per day) for 2 weeks before sacrifice, and compared with untreated HT and NT rats sacrificed at ages corresponding to either before or after the drug regimens. RESULTS: Systolic arterial pressure (SAP) of 2 and 4 week HT rats was increased in comparison to age-matched NT rats (P <0.05). Treatment with omapatrilat or lisinopril reduced SAP in HT (P <0.05) similarly by about 10%. Cardiac interstitial collagen, perivascular collagen and media/lumen ratio of coronary arterioles were increased in HT rats. Both treatments partially prevented the rise in perivascular collagen and completely corrected the increased media/lumen ratio in small arterioles from HT (P <0.05). In contrast to NT rats, only a weak coronary dilatation to bradykinin was observed in Langendorff hearts isolated from untreated-HT. This response was slightly improved by lisinopril and markedly improved by omapatrilat (P <0.05). The coronary dilatation to SNP which was reduced in 4-week HT (P <0.05), was partially improved by omapatrilat treatment but not by lisinopril. The enhanced superoxide anion production in aorta from HT rats was partially corrected with omapatrilat and lisinopril. Finally, omapatrilat, unlike lisinopril, markedly reduced mortality in a more severe form of DOCA-salt hypertension. CONCLUSIONS: Omapatrilat and lisinopril regressed coronary remodelling and cardiac collagen deposition, and reduced vascular oxidative stress in DOCA-salt hypertensive rats. However, despite similar antihypertensive efficacy, omapatrilat was superior to lisinopril in improving the endothelial-dependent coronary dilatation, suggesting a better vascular protection in the DOCA-salt model of hypertension. 相似文献
995.
Harteveld CL van Delft P Wijermans PW Kappers-Klunne MC Weegenaar J Losekoot M Giordano PC 《British journal of haematology》2003,120(2):364-366
We describe the characterization of a novel 7.9 kb deletion that eliminated one of the duplicated alpha-globin genes, causing an alpha+-thalassaemia phenotype in two independent carriers of Suriname-Indian origin. The molecular characterization of the deletion breakpoint fragment revealed neither involvement of Alu repeat sequences nor the presence of homologous regions prone to recombination, suggesting a non-homologous recombination event. This alpha+-thalassaemia deletion was found to give rise to an atypical haemoglobin H (HbH) disease characterized by a non-transfusion-dependent moderate microcytic hypochromic anaemia in combination with a poly adenylation signal mutation of the alpha-globin gene (alpha2 AATAAA --> AATA-- --). 相似文献
996.
A comparison of fibrosis progression in chronic liver diseases 总被引:13,自引:0,他引:13
Poynard T Mathurin P Lai CL Guyader D Poupon R Tainturier MH Myers RP Muntenau M Ratziu V Manns M Vogel A Capron F Chedid A Bedossa P;PANFIBROSIS Group 《Journal of hepatology》2003,38(3):257-265
BACKGROUND/AIMS: No study has compared the liver fibrosis progression rates among chronic liver diseases and the risk factors in order to better organize screening strategies. METHODS: A total of 4852 patients were retrospectively studied (chronic hepatitis C (HCV) [n=2313], human immunodeficiency virus (HIV)-HCV co-infection (HIV-HCV [n=180]), hepatitis B (HBV [n=777]), alcoholic liver disease (ALD [n=701]), primary biliary cirrhosis (PBC [n=406]), genetic hemochromatosis (GH [n=383]) auto-immune hepatitis (AIH [n=57]) and delta hepatitis (n=35). The fibrosis progression rates were estimated from birth and from the date of exposure, when known, to the first biopsy. RESULTS: There were highly significant differences in the rates of fibrosis progression, the most rapid being HIV-HCV co-infection (50% cirrhosis percentile at 52 years of age) and the slowest being PBC (50% cirrhosis percentile at 81 years). There was an acceleration of fibrosis progression with aging. Fibrosis progression was slower in females compared with males for HCV, HBV, GH, and PBC. In contrast, in ALD, the fibrosis progression was more rapid in females. CONCLUSIONS: Rates of fibrosis progression differ markedly between the predominant causes of chronic liver disease, and according to age and gender. Patients with HIV-HCV co-infection are at particularly high risk of fibrosis progression. 相似文献
997.
Pregnancy and Crohn's disease 总被引:3,自引:0,他引:3
Mottet C Juillerat P Gonvers JJ Froehlich F Burnand B Vader JP Michetti P Felley C 《Digestion》2005,71(1):54-61
Crohn's disease commonly affects women of childbearing age. Available data on Crohn's disease and pregnancy show that women with Crohn's disease can expect to conceive successfully, carry to term and deliver a healthy baby. Control of disease activity before conception and during pregnancy is critical, to optimize both maternal and fetal health. Generally speaking, pharmacological therapy for Crohn's disease during pregnancy is similar to pharmacological therapy for non-pregnant patients. Patients maintained in remission by way of pharmacological therapy should continue it throughout their pregnancy. Most drugs, including sulfasalazine, mesalazine, corticosteroids, and immunosuppressors such as azathioprine and 6-mercaptopurine, are safe, whereas methotrexate is contraindicated. 相似文献
998.
Cryopyrinopathies are a group of rare autoinflammatory diseases that includes familial cold autoinflammatory syndrome, Muckle-Wells syndrome and chronic infantile neurologic cutaneous articular syndrome (also termed neonatal-onset multisystemic inflammatory disease). These syndromes were initially considered to be distinct disease entities despite some clinical similarities; however, mutations of the same gene have since been found in all three cryopyrinopathies. These diseases, therefore, are not separate but represent a continuum of subphenotypes. The gene in question, CIAS1 (now renamed NLRP3) encodes NALP3 (also known as cryopyrin). NALP3 is an important mediator of inflammation and interleukin 1beta processing. New therapies based on biologic agents that specifically target interleukin 1beta are currently being developed. These new agents have provided very encouraging results for patients with these long-lasting inflammatory conditions--which used to be considered refractory to treatment. The development of therapeutic options for these cryopyrinopathies illustrates effective translation of basic science to clinical practice and the convergence of human genetics and targeted therapies. 相似文献
999.
Deenik W van der Holt B Verhoef GE Smit WM Kersten MJ Kluin-Nelemans HC Verdonck LF Ferrant A Schattenberg AV Janssen JJ Sonneveld P van Marwijk Kooy M Wittebol S Willemze R Wijermans PW Westveer PH Beverloo HB Valk P Löwenberg B Ossenkoppele GJ Cornelissen JJ 《Blood》2008,111(5):2581-2588
The HOVON cooperative study group performed a feasibility study of escalated imatinib and intravenous cytarabine in 165 patients with early chronic-phase chronic myeloid leukemia (CML). Patients received 2 cycles of intravenous cytarabine (200 mg/m(2) or 1000 mg/m(2) days 1-7) in conjunction with imatinib (200 mg, 400 mg, 600 mg, or 800 mg), according to predefined, successive dose levels. All dose levels proved feasible. Seven dose-limiting toxicities (DLTs) were observed in 302 cycles of chemotherapy, which were caused by streptococcal bacteremia in 5 cases. Intermediate-dose cytarabine (1000 mg/m(2)) prolonged time to neutrophil recovery and platelet recovery compared with a standard dose (200 mg/m(2)). High-dose imatinib (600 mg or 800 mg) extended the time to platelet recovery compared with a standard dose (400 mg). More infectious complications common toxicity criteria (CTC) grade 3 or 4 were observed after intermediate-dose cytarabine compared with a standard-dose of cytarabine. Early response data after combination therapy included a complete cytogenetic response in 48% and a major molecular response in 30% of patients, which increased to 46% major molecular responses at 1 year, including 13% complete molecular responses. We conclude that combination therapy of escalating dosages of imatinib and cytarabine is feasible. This study was registered at www.kankerbestrijding.nl as no. CKTO-2001-03. 相似文献
1000.