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71.
72.
J. Troy Blackburn Marc F. Norcross Lindsey N. Cannon Steven M. Zinder 《Journal of Athletic Training》2013,48(6):764-772
Context:
Greater hamstrings stiffness is associated with less anterior tibial translation during controlled perturbations. However, it is unclear how hamstrings stiffness influences anterior cruciate ligament (ACL) loading mechanisms during dynamic tasks.Objective:
To evaluate the influence of hamstrings stiffness on landing biomechanics related to ACL injury.Design:
Cross-sectional study.Setting:
Research laboratory.Patients or Other Participants:
A total of 36 healthy, physically active volunteers (18 men, 18 women; age = 23 ± 3 years, height = 1.8 ± 0.1 m, mass = 73.1 ± 16.6 kg).Intervention(s):
Hamstrings stiffness was quantified via the damped oscillatory technique. Three-dimensional lower extremity kinematics and kinetics were captured during a double-legged jump-landing task via a 3-dimensional motion-capture system interfaced with a force plate. Landing biomechanics were compared between groups displaying high and low hamstrings stiffness via independent-samples t tests.Main Outcome Measure(s):
Hamstrings stiffness was normalized to body mass (N/m·kg−1). Peak knee-flexion and -valgus angles, vertical and posterior ground reaction forces, anterior tibial shear force, internal knee-extension and -varus moments, and knee-flexion angles at the instants of each peak kinetic variable were identified during the landing task. Forces were normalized to body weight, whereas moments were normalized to the product of weight and height.Results:
Internal knee-varus moment was 3.6 times smaller in the high-stiffness group (t22 = 2.221, P = .02). A trend in the data also indicated that peak anterior tibial shear force was 1.1 times smaller in the high-stiffness group (t22 = 1.537, P = .07). The high-stiffness group also demonstrated greater knee flexion at the instants of peak anterior tibial shear force and internal knee-extension and -varus moments (t22 range = 1.729–2.224, P < .05).Conclusions:
Greater hamstrings stiffness was associated with landing biomechanics consistent with less ACL loading and injury risk. Musculotendinous stiffness is a modifiable characteristic; thus exercises that enhance hamstrings stiffness may be important additions to ACL injury-prevention programs.Key Words: viscoelastic, musculotendinous, valgus, anterior tibial shear forceKey Points
- Individuals with greater hamstrings stiffness displayed more favorable landing biomechanics for anterior cruciate ligament (ACL) loading and injury risk than individuals with less hamstrings stiffness as evidenced by smaller frontal-plane knee moments and a more-flexed knee at the instants of critical biomechanical knee events.
- Greater hamstrings stiffness was associated with smaller anterior tibial shear forces.
- A high level of hamstrings stiffness may limit ACL injury risk by limiting frontal- and sagittal-plane ACL-loading mechanisms.
73.
Helen Venn Barbara Montagne Lindsey Murray Michael Burt Elisa Frigerio 《Cognitive neuropsychiatry》2013,18(6):505-520
Introduction?A number of studies have reported mood‐congruent biases in processing facial expressions of emotion in depression and mania. Most of them have failed to establish that mood reliably affects relevant more than irrelevant expressions, or that the effect is specifically mood‐related rather than due to resource or task difficulty artefacts. The aim was to examine, using appropriate statistical methods, whether depressed mood in bipolar patients decreases and manic mood increases sensitivity to facial expressions of happiness and vice versa for facial expressions of negative emotion. Methods?Sensitivity to facial expression of six basic emotions in bipolar patients when depressed and when manic was compared to closely matched controls. Results?Mood‐related biases in sensitivity to facial expressions of happiness and of negative affect in general operate in persons with bipolar disorder when depressed. There is little evidence of similar biases in persons with bipolar disorder when manic. Conclusions?These data show a mood‐congruent bias in sensitivity to facial expressions in bipolar depressed patients. 相似文献
74.
Dual echo vessel‐encoded ASL for simultaneous BOLD and CBF reactivity assessment in patients with ischemic cerebrovascular disease 下载免费PDF全文
75.
R. Paul Robertson Lindsey D. Bogachus Elizabeth Oseid Susan Parazzoli Mary Elizabeth Patti Michael R. Rickels Christian Schuetz Ty Dunn Timothy Pruett A.N. Balamurugan David E.R. Sutherland Gregory Beilman Melena D. Bellin 《Diabetes》2015,64(2):565-572
We used intravenous arginine with measurements of insulin, C-peptide, and glucagon to examine β-cell and α-cell survival and function in a group of 10 chronic pancreatitis recipients 1–8 years after total pancreatectomy and autoislet transplantation. Insulin and C-peptide responses correlated robustly with the number of islets transplanted (correlation coefficients range 0.81–0.91; P < 0.01–0.001). Since a wide range of islets were transplanted, we normalized the insulin and C-peptide responses to the number of islets transplanted in each recipient for comparison with responses in normal subjects. No significant differences were observed in terms of magnitude and timing of hormone release in the two groups. Three recipients had a portion of the autoislets placed within their peritoneal cavities, which appeared to be functioning normally up to 7 years posttransplant. Glucagon responses to arginine were normally timed and normally suppressed by intravenous glucose infusion. These findings indicate that arginine stimulation testing may be a means of assessing the numbers of native islets available in autologous islet transplant candidates and is a means of following posttransplant α- and β-cell function and survival. 相似文献
76.
Self‐Reported Outcomes in Individuals Aged 65 and Older Admitted for Treatment to an Acute Care Surgical Service: A 6‐Month Prospective Cohort Study 下载免费PDF全文
77.
78.
79.
Goldblatt D Hussain M Andrews N Ashton L Virta C Melegaro A Pebody R George R Soininen A Edmunds J Gay N Kayhty H Miller E 《The Journal of infectious diseases》2005,192(3):387-393
BACKGROUND: Natural immunity to Streptococcus pneumoniae is thought to be induced by exposure to S. pneumoniae or cross-reactive antigens. No longitudinal studies of carriage of and immune responses to S. pneumoniae have been conducted using sophisticated immunological laboratory techniques. METHODS: We enrolled 121 families with young children into this study. Nasopharyngeal (NP) swabs were collected monthly for 10 months from all family members and were cultured in a standard fashion. Cultured S. pneumoniae isolates were serotyped. At the beginning (month 0) and end (month 10) of the study, venous blood was collected from family members >18 years old. Serotype-specific antipolysaccharide immunoglobulin G (IgG) and functional antibody and antibodies to pneumolysin, pneumococcal surface protein A (PspA), and pneumococcal surface antigen A (PsaA) were measured in paired serum samples. RESULTS: Levels of anticapsular IgG increased significantly after carriage of serotypes 9V, 14, 18C, 19F, and 23F by an individual or family member. For serotype 14, a higher level of anticapsular IgG at the beginning of the study was associated with reduced odds of carriage (P = .006). There was a small (approximately 20%) but significant increase in titers of antibodies to PsaA and pneumolysin but no change in titers of antibody to PspA. CONCLUSIONS: Adults respond to NP carriage by mounting anticapsular and weak antiprotein antibody responses, and naturally induced anticapsular IgG can prevent carriage. 相似文献