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91.
The ratio of the double-bond content of monomer to polymer, i.e. degree of conversion (DC) has been used frequently as a convenient means of comparing the behavior and properties of dental composites and adhesives. The purpose of this investigation was to study the relationship of photopolymerization processes, bulk properties, and structure using model dentin adhesives cured in the presence of different ethanol content as an example. There was little difference in the DC of model BisGMA-based adhesives cured in the presence of ethanol concentrations ranging from 0 to 40 wt %, but there were substantial differences in the mechanical properties. Ultimate tensile strength (UTS) and modulus of elasticity decreased with an increase in ethanol content. Polymer structure was revealed by thermal behavior in the glass transition temperature (Tg) region; these measurements were obtained by modulated temperature differential scanning calorimetry (MTDSC) technology, which removes the competing irreversible effects associated with release of volatiles and residual curing. Glass transition temperature of model adhesives decreased substantially with an increase in ethanol content. The DC based on the quantity of remaining double bond has been used extensively to characterize and provide a relative assessment of the quality of dentin adhesives and dental composites. Since polymers differing in linearity, and therefore crosslink density, may have a similar degree of conversion, the measurement of monomer/polymer conversion does not necessarily provide complete representation of the quality or durability of the polymer structure. 相似文献
92.
Kjeldsen SE Lyle PA Kizer JR Oparil S Høieggen A Os I 《Vascular health and risk management》2007,3(3):299-305
A fixed-dose combination of losartan/hydrochlorothiazide (HCTZ) therapy may be a logical choice for antihypertensive treatment, including for initial therapy in patients with blood pressure elevation >20/10 mmHg above treatment target. The renin-angiotensin-aldosterone-system-activating effect of hydrochlorothiazide augments the efficacy of blocking the angiotensin II type 1 (AT1) receptor with losartan. Some adverse effects associated with hydrochlorothiazide, including increased risk for new-onset diabetes mellitus, may be offset by losartan. Losartan was frequently administered with hydrochlorothiazide in the Losartan Intervention For Endpoint reduction in hypertension (LIFE) study, in which there was a 25% risk reduction for stroke in the losartan-based compared with the atenolol-based treatment group. The efficacy, tolerability, and convenience of losartan/HCTZ combination therapy may increase patient compliance and lower risk for stroke, a devastating outcome in patients with hypertension. 相似文献
93.
Jinhan Xie MPharm PhD Amit Kumar PhD M. Emmy M. Dolman PhD Chelsea Mayoh BSc Dong-Anh Khuong-Quang MD PhD Roxanne Cadiz BSc Marie Wong-Erasmus PhD Emily V. A. Mould PhD Dylan Grebert-Wade BSc Paulette Barahona PhD Alvin Kamili BMedSc PhD Maria Tsoli PhD Timothy W. Failes PhD Shu-Oi Chow BSc Greg M. Arndt BSc PhD Kanika Bhatia MD Glenn M. Marshall AM MB BS MD FRACP David S. Ziegler MBBS BSc FRACP MD Michelle Haber AM PhD Hon DSc FAHMS Richard B. Lock BSc PhD Vanessa Tyrrell BAppSc MHGSA FHGSA MBA CSA ARCPA Loretta Lau MBBS MMed PhD FRACP Penny Athanasatos BAppSc CT CF Andrew J. Gifford BSc Hons PhD MBBS FRCPA 《Cancer cytopathology》2021,129(10):805-818
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Nijamkin MP Campa A Sosa J Baum M Himburg S Johnson P 《Journal of the Academy of Nutrition and Dietetics》2012,112(3):382-390
BackgroundAs morbid obesity increasingly affects Hispanic Americans, the incidence of bariatric procedures among this population is rising. Despite this, prospective research on the effects of comprehensive postoperative education-centered interventions on weight loss and physical activity focused on Hispanic Americans is lacking.ObjectiveTo examine whether a comprehensive nutrition education and behavior modification intervention improves weight loss and physical activity in Hispanic Americans with obesity following Roux-en-Y gastric bypass surgery (RYGB).MethodsA prospective randomized-controlled trial was conducted between November 2008 and April 2010. At 6 months following RYGB, 144 Hispanic Americans with obesity were randomly assigned to a comprehensive nutrition and lifestyle educational intervention (n=72) or a noncomprehensive approach (comparison group n=72). Those in the comprehensive group received education sessions every other week for 6 weeks in small groups and frequent contact with a registered dietitian. Those in the comparison group received brief, printed healthy lifestyle guidelines. Patients were reassessed at 12 months following surgery. Main outcome measures were excess weight loss and physical activity changes over time. Statistical analyses used t test, χ2 test, Wilcoxon signed rank, Mann-Whitney U test, and intent-to-treat analysis, significance P<0.05.ResultsParticipants (mean age 44.5±13.5 years) were mainly Cuban-born women (83.3%). Mean preoperative excess weight and body mass index (calculated as kg/m2) were 72.20±27.81 kg and 49.26±9.06, respectively. At 12 months following surgery, both groups lost weight significantly, but comprehensive group participants experienced greater excess weight loss (80% vs 64% from preoperative excess weight; P<0.001) and greater body mass index reduction (6.48±4.37 vs 3.63±3.41; P<0.001) than comparison group participants. Comprehensive group participants were significantly more involved in physical activity (+14 min/wk vs ?4 min/wk; P<0.001) than comparison group participants. Mean protein intake was significantly lower in the comparison group than that in the comprehensive group (P<0.024).ConclusionsFindings support the importance of comprehensive nutrition education for achieving more effective weight reduction in Hispanic Americans following RYGB. 相似文献
98.
Liliane Dubuisson Dr. Paulette Bioulac Jean Saric Charles Balabaud 《Digestive diseases and sciences》1982,27(11):1003-1010
The principal reported morphological consequence of portacaval shunt in the rat is liver atrophy. The present study was designed to investigate ultrastructural changes in hepatocytes using electron microscopy morphometry. Two weeks following portacaval shunt, rat livers were fixed by perfusion and hepatocyte organelles from the two opposite zones of the acinus (zones 1 and 3) were quantified. Liver weight/body weight decreased by 50%, hepatocyte-specific volume decreased by 30% (28% in zone 1 and 35% in zone 3). Estimated sinusoidal space increased, and estimated number of hepatocytes decreased by 50%. Hepatocytes had a normal ultrastructure except for mitochondria. Smooth endoplasmic reticulum-specific surface area was reduced by 65% (zone 3), and rough endoplasmic reticulum surface density was increased in zone 1 only. Mitochondriaspecific volume was unchanged but decreased inner and outer membrane-specific surface area in zone 3 suggests in this zone a change in their conformation and possibly their number. Golgi-rich area surface density increased but not significantly. Hepatocyte loss and atrophy and rearrangement of organelles represent a new ultrastructural steady state following portacaval shunt that may help explain the new functional steady state. 相似文献
99.
Kjeldsen SE Lyle PA Kizer JR Dahlöf B Devereux RB Julius S Beevers G de Faire U Fyhrquist F Ibsen H Kristianson K Lederballe-Pedersen O Lindholm LH Nieminen MS Omvik P Oparil S Snapinn SM Harris KE Wedel H;LIFE Study Group 《Journal of clinical hypertension (Greenwich, Conn.)》2005,7(3):152-158
The Losartan Intervention For Endpoint reduction in hypertension (LIFE) study reported that a losartan-based antihypertensive regimen reduced cardiovascular morbidity and mortality (composite of cardiovascular death, stroke, and myocardial infarction) more than therapy based on atenolol in patients with left ventricular hypertrophy and isolated systolic hypertension (ISH). Patients aged 55-80 years with blood pressures 160-200/<90 mm Hg were followed for a mean of 4.7 years. Blood pressure was similarly reduced in the losartan (n=660) and atenolol (n=666) ISH groups. There were 88 (6.6%) patients who experienced a stroke, 18 of which were fatal. Of patients experiencing strokes, 72.7% had an ischemic stroke. ISH patients in LIFE compared to the non-ISH group had a higher incidence of any stroke and embolic stroke, and similar incidences of fatal, atherosclerotic, and hemorrhagic/other strokes. The incidence of any stroke (40% risk reduction [RR], p=0.02), fatal stroke (70% RR, p=0.035), and atherothrombotic stroke (45% RR, p=0.022) was significantly lower in losartan-treated compared to the atenolol-treated patients. The 36% RR for embolic strokes in the losartan group was not statistically significantly (p=0.33) different from the atenolol group. These data suggest that losartan-based treatment is more effective than an atenolol-based treatment for patients with ISH and a high risk for stroke. 相似文献
100.
Alterations in platelet-generated thromboxane A2 (TXA2) and vessel wall-generated prostacyclin (PGI2) have been assoclated with myocardial ischemia. To examine TXA2 - PGI2 equilibrium at rest and during exercise stress, we studied 13 normal subjects and 15 coronary artery disease patients. Plasma TXB2 and 6-keto-PGF1α were measured as stable metabolites of TXA2 and PGI2, respectively, by radioimmunoassay. In normal subjects, plasma TXB2 levels increased 24% during exercise from 135 ± 30 to 168 ± 42 pg/ml (p = NS). Plasma 6-keto-PGF1α levels increased 224% from 54 ± 17 to 175 ± 57 pg/ml (p < 0.05). In coronary artery disease patients, although resting plasma TXB2 levels (mean 136 ± 43 pg/ml) were comparable to levels in normal subjects, a greater increase (82%) occurred during exercise (mean 248 ± 70 pg/ml; p < 0.02 compared to resting levels). Resting plasma 6-keto-PGF1α levels (mean 94 ± 28 pg/ml) were also similar to normal subjects but increased only by 43% during exercise (mean 134 ± 53 pg/ml; p = NS compared to resting levels). These data suggest that: in normal subjects TXA2 and PGI2 increase during exercise, PGI2 increasing more than TXA2, and although coronary disease patients have resting TXA2 and PGI2 levels in the normal range, TXA2 levels increase more than PGI2 levels during exercise. These observations may have a bearing on the mechanism of exercise-induced angina pectoris in certain coronary artery disease patients. 相似文献