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91.
Velez Erik Fedorov Andriy Tuncali Kemal Olubiyi Olutayo Allard Christopher B. Kibel Adam S. Tempany Clare M. 《Abdominal imaging》2017,42(8):2154-2159
Abdominal Radiology - To determine the accuracy of in-bore transperineal 3-Tesla (T) magnetic resonance (MR) imaging-guided prostate biopsies for predicting final Gleason grades in patients who... 相似文献
92.
OBJECTIVE: To improve our ability to identify physiologic deterioration caused by critical illness, we applied nonlinear and frequency-domain analytical methods to R-to-R interval (RRI) and systolic arterial pressure (SAP) time series during hemorrhagic shock. DESIGN: Prospective, randomized, controlled trial. SETTING: Animal laboratory of a government research institute. SUBJECTS: Twenty swine (weight 36.4+/-0.11 kg). INTERVENTIONS: Fixed-volume hemorrhage followed by resuscitation; off-line analysis of RRI and SAP data. MEASUREMENTS AND MAIN RESULTS: Anesthetized swine (shock group, n=12) underwent withdrawal of 30 mL/kg blood in 10 mL/kg decrements. A control group (n=8) received maintenance fluids only. Electrocardiogram and arterial pressure waveforms were acquired at 500 Hz. Eight hundred-beat data sets were analyzed at six time points: at baseline, after each blood withdrawal, after lactated Ringer's resuscitation, and after infusion of shed blood. Nonlinear methods were used to estimate the complexity (approximate entropy, sample entropy, Lempel-Ziv entropy, normalized entropy of symbol dynamics), RRI bits per word, and fractal dimension by curve lengths and by dispersion analysis of the RRI and SAP time series. Fast Fourier transformation was used to measure the high-frequency and low-frequency powers of RRI and SAP. Baroreflex sensitivity was assessed in the time domain with the sequence method. Hemorrhagic shock caused decreases in RRI complexity as quantified by approximate entropy, sample entropy, and symbol dynamics; these changes were reversed by resuscitation. Similar but statistically insignificant changes in fractal dimension by curve lengths were seen. RRI high-frequency power decreased with hemorrhagic shock-indicating withdrawal of vagal cardiac input-and was restored by resuscitation. Similar changes in baroreflex sensitivity were seen. Hemorrhagic shock did not affect SAP complexity. CONCLUSIONS: Hemorrhagic shock caused a reversible decrease in RRI complexity; these changes may be mediated by changes in vagal cardiac control. Assessment of RRI complexity may permit identification of casualties with hemorrhagic shock. 相似文献
93.
Nehemiah T. Liu Andriy I. BatchinskyLeopoldo C. Cancio MD William L. Baker JrJose Salinas PhD 《Journal of critical care》2013
Purpose
Previous studies have shown that heart rate complexity may be a useful indicator of patient status in the critical care environment but will require continuous, accurate, and automated R-wave detection (RWD) in the electrocardiogram (ECG). Although numerous RWD algorithms exist, accurate detection remains a challenge. The purpose of this study was to develop and validate a novel fusion algorithm (Automated Electrocardiogram Selection of Peaks, or AESOP) that combines the strengths of several well-known algorithms to provide a more reliable real-time solution to the RWD problem.Materials and Methods
This study involved the ECGs of 108 prehospital patient records and 32 ECGs from a conscious sedated porcine model of hemorrhagic shock. The criterion standard for validation was manual verification of R waves.Results
For 108 human ECG records, the AESOP algorithm overall outperformed each of its component algorithms. In addition, for 32 swine ECG records, AESOP achieved an R-wave sensitivity of 97.9% and a positive predictive value of 97.5%, again outperforming its component algorithms.Conclusion
By fusing several best algorithms, AESOP uses the strengths of each algorithm to perform more robustly and reliably in real time. The AESOP algorithm will be integrated into a real-time heart rate complexity software program for decision support and triage in critically ill patients. 相似文献94.
Many association tests have been proposed for rare variants, but the choice of a powerful test is uncertain when there is limited information on the underlying genetic model. Proposed methods use either linear statistics, which are powerful when most variants are causal and have the same direction of effect, or quadratic statistics, which are more powerful in other scenarios. To achieve robustness, it is natural to combine the evidence of association from two or more complementary tests. To this end, we consider the minimum‐p and Fisher's methods of combining P‐values from linear and quadratic statistics. Extensive simulation studies show that both methods are robust across models with varying proportions of causal, deleterious, and protective rare variants, allele frequencies, and effect sizes. When the majority (>75%) of the causal effects are in the same direction (deleterious or protective), Fisher's method consistently outperforms the minimum‐p and the individual linear and quadratic tests, as well as the optimal sequence kernel association test, SKAT‐O. When the individual test has moderate power, Fisher's test has improved power for 90% of the ~5000 models considered, with >20% relative efficiency gain for 40% of the models. The maximum absolute power loss is 8% for the remaining 10% of the models. An application to the GAW17 quantitative trait Q2 data based on sequence data of the 1000 Genomes Project shows that, compared with linear and quadratic tests, Fisher's test has comparable power for all 13 functional genes and provides the best power for more than half of them. 相似文献
95.
Farias Quipildor Gabriela E. Mao Kai Hu Zunju Novaj Ardijana Cui Min-Hui Gulinello Maria Branch Craig A. Gubbi Sriram Patel Khushbu Moellering Douglas R. Tarantini Stefano Kiss Tamas Yabluchanskiy Andriy Ungvari Zoltan Sonntag William E. Huffman Derek M. 《Age (Dordrecht, Netherlands)》2019,41(2):185-208
GeroScience - Disruptions in growth hormone/insulin-like growth factor-1 (GH/IGF-1) signaling have been linked to improved longevity in mice and humans. Nevertheless, while IGF-1 levels are... 相似文献
96.
Demuro A Penna A Safrina O Yeromin AV Amcheslavsky A Cahalan MD Parker I 《Proceedings of the National Academy of Sciences of the United States of America》2011,108(43):17832-17837
We applied single-molecule photobleaching to investigate the stoichiometry of human Orai1 and Orai3 channels tagged with eGFP and expressed in mammalian cells. Orai1 was detected predominantly as dimers under resting conditions and as tetramers when coexpressed with C-STIM1 to activate Ca(2+) influx. Orai1 was also found to be tetrameric when coexpressed with STIM1 and evaluated following fixation. We show that fixation rapidly causes release of Ca(2+), redistribution of STIM1 to the plasma membrane, and STIM1/Orai1 puncta formation, and may cause the channel to be in the activated state. Consistent with this possibility, Orai1 was found predominantly as a dimer when coexpressed with STIM1 in living cells under resting conditions. We further show that Orai3, like Orai1, is dimeric under resting conditions and is predominantly tetrameric when activated by C-STIM1. Interestingly, a dimeric Orai3 stoichiometry was found both before and during application of 2-aminoethyldiphenyl borate (2-APB) to activate a nonselective cation conductance in its STIM1-independent mode. We conclude that the human Orai1 and Orai3 channels undergo a dimer-to-tetramer transition to form a Ca(2+)-selective pore during store-operated activation and that Orai3 forms a dimeric nonselective cation pore upon activation by 2-APB. 相似文献
97.
98.
Robert L. Sprando Renate Reimschuessel Cynthia B. Stine Thomas Black Nicholas Olejnik Michael Scott Zachary Keltner Omari Bandele Martine Ferguson Sarah M. Nemser Andriy Tkachenko Eric Evans Tina Crosby Kellie Woodling Lucie Loukotková Gonçalo Gamboa da Costa 《Food and chemical toxicology》2012
Effects of the dosing matrix and timing on the onset of renal crystal formation were evaluated in male and non-pregnant female rats (Fisher 344) exposed to both melamine (MEL) and cyanuric acid (CYA) for 28 days. Rats were fed ground feed containing 60 ppm MEL and 60 ppm CYA, (5 mg/kg bw/day equivalent), or exposed via oral gavage to carboxymethylcellulose containing 5 mg/kg bw MEL followed by 5 mg/kg bw CYA either consecutively (<1 min apart) or delayed 45 min after MEL. Staggered gavage exposure to MEL/CYA caused extensive renal crystal formation as compared to when the two compounds were administered consecutively or in feed. Treatment related effects included reduced weight gain, feed consumption, and testicular weight and increased kidney weight, water consumption and urine output. Animals from the staggered MEL/CYA gavage exposure group became ill and were removed after 9 days of exposure. Approximately 1 week after the initiation of exposure microscopic urinalysis revealed MEL/CYA crystals in both groups of gavaged animals but not in the MEL/CYA feed treatment groups. Urinary crystals were smaller (10 μm) in animals consecutively gavaged. In contrast the urinary crystals were larger (20–40 μm) and frequently clumped in the animals in the staggered gavage group. 相似文献
99.
100.
Farfán EB Gaschak SP Maksymenko AM Jannik GT Marra JC Bondarkov MD Donnelly EH 《Health physics》2011,100(2):221-227
Several issues should be considered when assessing the feasibility of remediation following the detonation of a radiological dispersion device (e.g., dirty bomb) or improvised nuclear device in a large city. These issues include the levels and characteristics of the radioactive contamination, the availability of resources required for decontamination, and the planned future use of the city's structures and buildings. Presently, little is known about the distribution, redistribution, and migration of radionuclides in an urban environment. However, Pripyat, a city substantially contaminated by the Chernobyl Nuclear Power Plant accident in April 1986, may provide some answers. The main objective of this study was to determine the radionuclide distribution on a Pripyat multistory building that had not been decontaminated and, therefore, could reflect the initial fallout and its further natural redistribution on external surfaces over 23 y. The seven-story building selected was surveyed from the ground floor to the roof on horizontal and vertical surfaces along seven ground-to-roof transections. Some results from this study indicate that the upper floors of the building had higher contamination levels than the lower floors. Consequently, the authors recommend that thorough decontamination should be considered for all the floors of tall buildings (not just lower floors). 相似文献