全文获取类型
收费全文 | 3209篇 |
免费 | 121篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 41篇 |
儿科学 | 38篇 |
妇产科学 | 41篇 |
基础医学 | 499篇 |
口腔科学 | 24篇 |
临床医学 | 413篇 |
内科学 | 657篇 |
皮肤病学 | 29篇 |
神经病学 | 282篇 |
特种医学 | 131篇 |
外科学 | 474篇 |
综合类 | 4篇 |
一般理论 | 1篇 |
预防医学 | 180篇 |
眼科学 | 32篇 |
药学 | 304篇 |
中国医学 | 6篇 |
肿瘤学 | 187篇 |
出版年
2023年 | 9篇 |
2022年 | 9篇 |
2021年 | 84篇 |
2020年 | 24篇 |
2019年 | 52篇 |
2018年 | 74篇 |
2017年 | 53篇 |
2016年 | 43篇 |
2015年 | 72篇 |
2014年 | 75篇 |
2013年 | 117篇 |
2012年 | 254篇 |
2011年 | 258篇 |
2010年 | 128篇 |
2009年 | 128篇 |
2008年 | 245篇 |
2007年 | 250篇 |
2006年 | 272篇 |
2005年 | 253篇 |
2004年 | 236篇 |
2003年 | 200篇 |
2002年 | 211篇 |
2001年 | 23篇 |
2000年 | 15篇 |
1999年 | 13篇 |
1998年 | 26篇 |
1997年 | 34篇 |
1996年 | 13篇 |
1995年 | 32篇 |
1994年 | 19篇 |
1993年 | 22篇 |
1992年 | 17篇 |
1991年 | 3篇 |
1990年 | 8篇 |
1989年 | 10篇 |
1988年 | 15篇 |
1987年 | 3篇 |
1986年 | 7篇 |
1985年 | 4篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 6篇 |
1974年 | 2篇 |
1966年 | 1篇 |
排序方式: 共有3343条查询结果,搜索用时 31 毫秒
1.
Alice Le Clech Noémie Simon-Tillaux François Provôt Yahsou Delmas Paula Vieira-Martins Sophie Limou Jean-Michel Halimi Moglie Le Quintrec Ludivine Lebourg Steven Grangé Alexandre Karras David Ribes Noémie Jourde-Chiche Eric Rondeau Véronique Frémeaux-Bacchi Fadi Fakhouri 《Kidney international》2019,95(6):1443-1452
2.
Bruno Mgarbane Fanchon Bourasset Jean-Michel Scherrmann 《Journal of general internal medicine》2021,36(3):746
BackgroundTo date, the risk/benefit balance of lockdown in controlling severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) epidemic is controversial.ObjectiveWe aimed to investigate the effectiveness of lockdown on SARS-CoV-2 epidemic progression in nine different countries (New Zealand, France, Spain, Germany, the Netherlands, Italy, the UK, Sweden, and the USA).DesignWe conducted a cross-country comparative evaluation using a susceptible-infected-recovered (SIR)-based model completed with pharmacokinetic approaches.Main MeasuresThe rate of new daily SARS-CoV-2 cases in the nine countries was calculated from the World Health Organization’s published data. Using a SIR-based model, we determined the infection (β) and recovery (γ) rate constants; their corresponding half-lives (t1/2β and t1/2γ); the basic reproduction numbers (R0 as β/γ); the rates of susceptible S(t), infected I(t), and recovered R(t) compartments; and the effectiveness of lockdown. Since this approach requires the epidemic termination to build the (I) compartment, we determined S(t) at an early epidemic stage using simple linear regressions.Key ResultsIn New Zealand, France, Spain, Germany, the Netherlands, Italy, and the UK, early-onset stay-at-home orders and restrictions followed by gradual deconfinement allowed rapid reduction in SARS-CoV-2-infected individuals (t1/2β ≤ 14 days) with R0 ≤ 1.5 and rapid recovery (t1/2γ ≤ 18 days). By contrast, in Sweden (no lockdown) and the USA (heterogeneous state-dependent lockdown followed by abrupt deconfinement scenarios), a prolonged plateau of SARS-CoV-2-infected individuals (terminal t1/2β of 23 and 40 days, respectively) with elevated R0 (4.9 and 4.4, respectively) and non-ending recovery (terminal t1/2γ of 112 and 179 days, respectively) was observed.ConclusionsEarly-onset lockdown with gradual deconfinement allowed shortening the SARS-CoV-2 epidemic and reducing contaminations. Lockdown should be considered as an effective public health intervention to halt epidemic progression.KEY WORDS: COVID-19, epidemic, lockdown, modeling, pharmacokinetics, SARS-CoV-2 相似文献
3.
4.
5.
6.
7.
Kinetic Slip Boundary Condition for Isothermal Rarefied Gas Flows Through Static Non-Planar Geometries Based on the Regularized Lattice-Boltzmann Method 下载免费PDF全文
Jean-Michel Tucny David Vidal Sé bastien Leclaire & Franç ois Bertrand 《Communications In Computational Physics》2022,31(3):816-868
The simulation of rarefied gas flows through complex porous media is challenging due to the tortuous flow pathways inherent to such structures. The Lattice
Boltzmann method (LBM) has been identified as a promising avenue to solve flows
through complex geometries due to the simplicity of its scheme and its high parallel
computational efficiency. It has been proposed to model the stress-strain relationship
with the extended Navier-Stokes equations rather than attempting to directly solve
the Boltzmann equation. However, a regularization technique is required to filter out
non-resolved higher-order components with a low-order velocity scheme. Although
slip boundary conditions (BCs) have been proposed for the non-regularized multiple
relaxation time LBM (MRT-LBM) for planar geometries, previous slip BCs have never
been verified extensively with the regularization technique. In this work, following
an extensive literature review on the imposition of slip BCs for rarefied flows with the
LBM, it is proven that earlier values for kinetic parameters developed to impose slip
BCs are inaccurate for the regularized MRT-LBM and differ between the D2Q9 and
D3Q15 schemes. The error was eliminated for planar flows and good agreement between analytical solutions for arrays of cylinders and spheres was found with a wide
range of Knudsen numbers. 相似文献
8.
Sathit Pichyangkul Somporn Krasaesub Anan Jongkaewwattana Arunee Thitithanyanont Suwimon Wiboon-ut Kosol Yongvanitchit Amporn Limsalakpetch Utaiwan Kum-Arb Duangrat Mongkolsirichaikul Nuanpan Khemnu Rangsini Mahanonda Jean-Michel Garcia Carl J. Mason Douglas S. Walsh David L. Saunders 《The American journal of tropical medicine and hygiene》2014,90(1):149-152
We studied cross-reactive antibodies against avian influenza H5N1 and 2009 pandemic (p) H1N1 in 200 serum samples from US military personnel collected before the H1N1 pandemic. Assays used to measure antibodies against viral proteins involved in protection included a hemagglutination inhibition (HI) assay and a neuraminidase inhibition (NI) assay. Viral neutralization by antibodies against avian influenza H5N1 and 2009 pH1N1 was assessed by influenza (H5) pseudotyped lentiviral particle-based and H1N1 microneutralization assays. Some US military personnel had cross-neutralizing antibodies against H5N1 (14%) and 2009 pH1N1 (16.5%). The odds of having cross-neutralizing antibodies against 2009 pH1N1 were 4.4 times higher in subjects receiving more than five inactivated whole influenza virus vaccinations than those subjects with no record of vaccination. Although unclear if the result of prior vaccination or disease exposure, these pre-existing antibodies may prevent or reduce disease severity.Outbreaks of 1997 avian influenza H5N1 and 2009 pandemic (p) H1N1 in humans have provided an opportunity to gain insight into cross-reactive immunity. The US military periodically collects and stores serum samples from service members linked to medical records.1 We measured cross-reactive antibodies in stored serum to avian influenza H5N1 and 2009 pH1N1 from US military personnel and identified factors associated with presence of neutralizing antibodies.Two hundred archived serum samples were obtained from the US Department of Defense Serum Repository. They were representative of a wide cross-section of active military personnel at the times of collection, whereas specific geographic information was not available on the individual selected; the cohort represents the general US military population, which is deployed throughout the United States and globally. Fifty samples each were selected from four birth cohorts: (1) < 1949, (2) 1960–1965, (3) 1966–1971, and (4) 1972–1977. Within each cohort, 25 samples were collected in the year 2000 (before the introduction of intranasal live attenuated influenza vaccine [LAIV]), and 25 samples were collected in 2008 (where 51% of donors had received LAIV). It has been suggested that LAIV elicits cross-reactive immunity.2,3 The samples were all collected before the outbreak of 2009 pH1N1, and there have not been any reported outbreaks of H5N1 in US military personnel.Assays used to measure antibodies included a hemagglutination inhibition (HI) assay and a neuraminidase inhibition (NI) assay.4 Viral neutralization by antibodies against H5N1 and 2009 pH1N1 was assessed by influenza (H5) pseudotyped lentiviral particle-based (H5pp)5 and microneutralization assays, respectively. Electronic medical and vaccination records from the Defense Medical Surveillance System (DMSS), which captured records before the serum sample date, were linked to samples and compared with the in vitro results.1The odds ratios (ORs) and 95% confidence intervals (95% CIs) of univariate and multivariate binary logistic regression analyses were used to determine the association between donor characteristics and positive antibody responses. A multiple logistic regression model was constructed, and it included independent variables with a P value of < 0.05 in univariate logistic regression. A P value of < 0.05 was considered to indicate statistical significance. SPSS 12.0 for Windows (SPSS Inc., Chicago, IL) was used to perform all statistical analysis.Cross-reactivity is summarized in 5 and 22.5% for the NI assay. H5pp and NI antibody titers to H5N1 were evenly distributed among birth cohorts and did not differ substantially based on history of vaccination or prior respiratory infections. Of those individuals with neutralizing antibodies to H5N1 (N = 28), 32.1% also had neutralizing antibodies to pH1N1, whereas 19.3% of those individuals with any H5N1-specific antibody response also had neutralizing antibodies to pH1N1 (Characteristics (n) H5N1 2009 pH1N1§ HI assay* % positive (GM titer) H5pp† % positive (GM titer) NI assay‡ % positive (GM titer) HI assay % positive (GM titer) Neutralization % positive (GM titer) NI assay % positive (GM titer) Total 200 0.5 (5.1) 14.0 (21.4) 22.5 (121.6) 5.5 (7.1) 16.5 (20.4) 9.0 (92.8) Birth cohort 1936–1949 (50) 2.0 (5.3) 18.0 (22.0) 24.0 (126.0) 6.0 (7.3) 16.0 (19.5) 12.0 (97.6) 1960–1965 (50) 0.0 (5.0) 16.0 (20.3) 26.0 (129.6) 6.0 (7.7) 30.0 (27.5) 6.0 (90.3) 1966–1971 (50) 0.0 (5.0) 12.0 (23.3) 20.0 (117.9) 10.0 (8.0) 16.0 (23.6) 10.0 (92.2) 1972–1977 (50) 0.0 (5.3) 10.0 (20.0) 20.0 (113.7) 0.0 (5.7) 4.0 (13.6) 8.0 (91.5) Serum collection year Y2000 (100) 0.0 (5.1) 15.0 (21.7) 21.0 (120.3) 7.0 (7.3) 16.0 (20.6) 11.0 (94.5) Y2008 (100) 1.0 (5.2) 13.0 (21.1) 24.0 (123.0) 4.0 (7.0) 17.0 (20.1) 7.0 (91.2) Sex Female (32) 3.1 (5.7) 21.9 (26.3) 12.5 (102.4) 3.1 (6.9) 12.5 (19.2) 6.3 (96.7) Male (168) 0.0 (5.0) 12.5 (20.5) 24.4 (125.7) 6.0 (7.2) 17.3 (20.6) 9.5 (92.1) Any cross-reactive antibody to H5N1 (57) 8.8 (8.9) 19.3 (25.2) 22.8 (119.9) pH1N1 (45) 2.2 (5.3) 28.9 (31.2) 37.8 (165.2) Neutralizing antibodies to H5N1 H5pp (28) 10.7 (9.5) 32.1 (33.6) 25.0 (116.9) 2009 pH1N1 neutralization (33) 3.0 (5.4) 27.3 (28.9) 30.3 (140.3) Lifetime seasonal vaccinations No record (66) 0.0 (5.1) 10.6 (20.2) 27.7 (128.1) 7.6 (7.4) 15.2 (20.6) 12.1 (96.5) 1–5 vaccinations (88) 1.1 (5.2) 15.9 (21.5) 17.0 (109.2) 5.7 (7.1) 17.0 (20.5) 6.8 (89.1) > 5 vaccinations (46) 0.0 (5.1) 15.2 (22.2) 32.6 (138.8) 2.2 (6.8) 17.4 (19.7) 8.7 (95.0) Time since last vaccine No record (66) 0.0 (5.1) 10.6 (20.2) 22.7 (128.1) 7.6 (7.4) 15.2 (20.6) 12.1 (96.5) ≤ 1 year (96) 0.0 (5.1) 15.6 (21.5) 24.0 (120.7) 4.2 (7.1) 19.8 (21.0) 8.3 (91.2) > 1 year (38) 2.6 (5.3) 15.8 (22.4) 18.4 (113.4) 5.2 (6.8) 10.5 (18.3) 5.3 (90.6) Vaccination history lifetime (at least one dose) No record of vaccination (66) 0.0 (5.1) 10.6 (20.2) 22.7 (128.1) 7.6 (7.4) 15.2 (20.6) 12.1 (96.5) Inactivated whole virus (71) 0.0 (5.0) 14.1 (20.4) 22.5 (115.7) 2.8 (6.4) 15.5 (19.6) 5.6 (87.1) Split type (102) 1.0 (5.0) 15.7 (20.4) 21.6 (115.7) 4.9 (6.4) 19.6 (19.6) 6.9 (87.1) Influenza vaccine not otherwise specified (16) 0.0 (5.2) 12.5 (27.9) 37.5 (166.4) 0.0 (6.2) 6.3 (16.1) 12.5 (102.3) Live attenuated intranasal (50) 0.0 (5.1) 10.0 (18.8) 20.0 (112.2) 4.0 (7.0) 18.0 (20.3) 4.0 (85.2) History of respiratory illness No record of illness (119) 0.0 (5.0) 10.1 (18.5) 18.5 (112.6) 4.2 (7.0) 15.1 (20.5) 8.4 (90.7) Influenza-like illness (4) 0.0 (5.0) 25.0 (20.7) 0.0 (80.0) 0.0 (8.4) 25.0 (28.3) 25.0 (100.2) Upper respiratory infection (65) 1.5 (5.4) 23.1 (29.3) 27.7 (135.0) 7.7 (7.3) 18.5 (20.7) 9.2 (93.1) Lower respiratory infection (37) 2.7 (5.6) 18.9 (30.2) 35.1 (157.6) 8.1 (8.1) 21.6 (22.4) 13.5 (108.4) Respiratory illness past year (28) 0 (5.1) 25.0 (25.1) 32.1 (154.9) 7.1 (8.0) 28.6 (24.4) 3.6 (86.3)