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41.
Jolanta Kumirska Mirko X. Weinhold Stephanie Steudte Jorg Thöming Krzysztof Brzozowski Piotr Stepnowski 《International journal of biological macromolecules》2009,45(1):56-60
Chitosan is a linear copolymer consisting of glucosamine and N-acetylglucosamine units. Its specific biological features make it a very attractive biomaterial for diverse applications in both pharmaceutics and medicine. The pattern of acetylation of chitosan samples (PA) can strongly influence their biomedical activities. So far, three methods of determining the PA value of chitosan samples, based on NMR spectroscopy, have been developed. Chitosans with a degree of acetylation (FA) from 0.02 to 0.48 were used to compare these methods. The most suitable and specific method of PA determination was 13C NMR based on the intensities of carbon C-5 signals. Some validation parameters—specificity, sensitivity, precision (repeatability and reproducibility)—were established. The intra- and inter-day precision of this method depended on the degree of acetylation of the chitosan samples. It was found to be specific, sensitive, repeatable and reproducible. 相似文献
42.
43.
Panagiotis N Margos Rolf Schomburg Jorg Kynast Ahmed A Khattab Gert Richardt 《Indian pacing and electrophysiology journal》2009,9(1):64-70
Implantable Cardioverter Defibrillator (ICD) implantation is the only established therapy for primary or secondary prevention of sudden cardiac death in patients with Hypertrophic Cardiomyopathy (HCM). Ineffectiveness of shock therapy for the termination of potentially fatal ventricular arrhythmias in ICD recipients is rare in the presence of appropriate arrhythmia detection by the device. We report the case of a 48-year-old woman with HCM and a single chamber ICD, who received five inefficient high-energy (35 Joules) shocks for the termination of an appropriately detected episode of Ventricular Tachycardia (VT). The episode was safely terminated with a subsequent application of Antitachycardia Pacing (ATP) by the device. At the following ICD control, an acceptable defibrillation threshold was detected. 相似文献
44.
William L. Blalock Cecilia Grimaldi Federica Fala Matilde Follo Stefan Horn Jorg Basecke Giovanni Martinelli Lucio Cocco Alberto M. Martelli 《Journal of cellular physiology》2009,221(1):232-241
Recent reports demonstrate that PKR is constitutively active in a variety of tumors and is required for tumor maintenance and growth. Here we report acute leukemia cell lines contain elevated levels of p‐T451 PKR and PKR activity as compared to normal controls. Inhibition of PKR with a specific inhibitor, as well as overexpression of a dominant‐negative PKR, inhibited cell proliferation and induced cell death. Interestingly, PKR inhibition using the specific inhibitor resulted in a time‐dependent augmentation of AKT S473 and GSK‐3α S21 phosphorylation, which was confirmed in patient samples. Increased phosphorylation of AKT and GSK‐3α was not dependent on PI3K activity. PKR inhibition augmented levels of p‐S473 AKT and p‐S21/9 GSK‐3α/β in the presence of the PI3K inhibitor, LY294002, but was unable to augment GSK‐3α or β phosphorylation in the presence of the AKT inhibitor, A443654. Pre‐treatment with the PKR inhibitor blocked the ability of A443654 and LY294002 to promote phosphorylation of eIF2α, indicating the mechanism leading to AKT phosphorylation and activation did not require eIF2α phosphorylation. The effects of PKR inhibition on AKT and GSK‐3 phosphorylation were found to be, in part, PP2A‐dependent. These data indicate that, in acute leukemia cell lines, constitutive basal activity of PKR is required for leukemic cell homeostasis and growth and functions as a negative regulator of AKT, thereby increasing the pool of potentially active GSK‐3. J. Cell. Physiol. 221: 232–241, 2009. © 2009 Wiley‐Liss, Inc 相似文献
45.
Satyendra Chandra Tripathi Ajay Matta Jatinder Kaur Jorg Grigull Shyam Singh Chauhan Alok Thakar Nootan Kumar Shukla Ritu Duggal Siddhartha DattaGupta Ranju Ralhan K. W. Michael Siu 《PloS one》2010,5(8)
Background
Tissue proteomic analysis of head and neck squamous cell carcinoma (HNSCC) and normal oral mucosa using iTRAQ (isobaric tag for relative and absolute quantitation) labeling and liquid chromatography-mass spectrometry, led to the identification of a panel of biomarkers including S100A7. In the multi-step process of head and neck tumorigenesis, the presence of dysplastic areas in the epithelium is proposed to be associated with a likely progression to cancer; however there are no established biomarkers to predict their potential of malignant transformation. This study aimed to determine the clinical significance of S100A7 overexpression in HNSCC.Methodology
Immunohistochemical analysis of S100A7 expression in HNSCC (100 cases), oral lesions (166 cases) and 100 histologically normal tissues was carried out and correlated with clinicopathological parameters and disease prognosis over 7 years for HNSCC patients. Overexpression of S100A7 protein was significant in oral lesions (squamous cell hyperplasia/dysplasia) and sustained in HNSCC in comparison with oral normal mucosa (ptrend<0.001). Significant increase in nuclear S100A7 was observed in HNSCC as compared to dysplastic lesions (p = 0.005) and associated with well differentiated squamous cell carcinoma (p = 0.031). Notably, nuclear accumulation of S100A7 also emerged as an independent predictor of reduced disease free survival (p = 0.006, Hazard ratio (HR = 7.6), 95% CI = 1.3−5.1) in multivariate analysis underscoring its relevance as a poor prognosticator of HNSCC patients.Conclusions
Our study demonstrated nuclear accumulation of S100A7 may serve as predictor of poor prognosis in HNSCC patients. Further, increased nuclear accumulation of S100A7 in HNSCC as compared to dysplastic lesions warrants a large-scale longitudinal study of patients with dysplasia to evaluate its potential as a determinant of increased risk of transformation of oral premalignant lesions. 相似文献46.
47.
Sarah Jamali Annick Salzmann Nader Perroud Magali Ponsole-Lenfant Jennifer Cillario Patrice Roll Nathalie Roeckel-Trevisiol Ariel Crespel Jorg Balzar Kurt Schlachter Ursula Gruber-Sedlmayr Ekaterina Pataraia Christoph Baumgartner Alexander Zimprich Fritz Zimprich Alain Malafosse Pierre Szepetowski 《PloS one》2010,5(9)
48.
Long-term observational studies in a number of animal species suggest that exchange patterns of social acts depend on long-term
emotional bonds. Therefore, it is expected that the frequency of prosocial behavior will depend on the strength of such a
bond. In this study we tested whether variation in relationship quality among unrelated individuals, i.e., “friends” and “nonfriends,”
is predictive of the prosocial behavior of long-tailed macaques in two experiments. First, we related relationship quality
to prosociality in a dyadic prosociality test, and second, we gave subjects the choice to give to either a friend or a nonfriend
in a triadic choice test. We show that prosocial behavior of long-tailed macaques in the dyadic test is not related to relationship
quality. When given the choice to give to either a friend or a nonfriend in the triadic test, there is a minor indication
that long-tailed macaques show a preference to give to their friends, yet this indication is neither significant nor consistent.
In contrast, subordinate long-tailed macaques make a more “competitive” choice and avoid giving to the individual closest
in rank. Therefore, in the short-term situation of experimental tests, prosocial behavior of long-tailed macaques seems unaffected
by the relationship quality of the dyad/triad tested, and the relative dominance position of these dyads/triads seems to have
a much stronger effect on their prosocial behavior. 相似文献
49.
Novel pyrazole and isoxazole derivatives (6-9) were synthesized as a aromatase inhibitors. Pyrazole was synthesized from hydrazine hydrate and isoxazoles from hydroxylamine hydrochloride under different conditions. Molecular docking studies were carried out for the synthesized compounds. The best score was obtained for the compound (9) followed by compound (6) while compound (8) afforded poorest of the score. Aromatase inhibitory activity for compound (6) having pyrazole ring at 2,3 position showed highest activity followed by nitrile derivative (9). Isomeric forms of isoxazole (7 and 8) showed very poor activity compared to fadrozole and aminoglutethimide. Preliminary kinetic studies have shown that both of the active compounds (6 and 9) are reversible inhibitors of the enzyme. 相似文献
50.
Chen W Li L Brod T Saeed O Thabet S Jansen T Dikalov S Weyand C Goronzy J Harrison DG 《The Journal of biological chemistry》2011,286(16):13846-13851
Tetrahydrobiopterin (BH(4)) is an essential co-factor for the nitric-oxide (NO) synthases, and in its absence these enzymes produce superoxide (O(2)(·-)) rather than NO. The rate-limiting enzyme for BH(4) production is guanosine triphosphate cyclohydrolase-1 (GTPCH-1). Because endogenously produced NO affects T cell function, we sought to determine whether antigen stimulation affected T cell GTPCH-1 expression and ultimately BH(4) levels. Resting T cells had minimal expression of inducible NOS (NOS2), endothelial NOS (NOS3), and GTPCH-1 protein and nearly undetectable levels of BH(4). Anti-CD3 stimulation of T cells robustly stimulated the coordinated expression of NOS2, NOS3, and GTPCH-1 and markedly increased both GTPCH-1 activity and T cell BH(4) levels. The newly expressed GTPCH-1 was phosphorylated on serine 72 and pharmacological inhibition of casein kinase II reduced GTPCH-1 phosphorylation and blunted the increase in T cell BH(4). Inhibition of GTPCH-1 with diaminohydroxypyrimidine (1 mmol/liter) prevented T cell BH(4) accumulation, reduced NO production, and increased T cell O(2)(·-) production, due to both NOS2 and NOS3 uncoupling. GTPCH-1 inhibition also promoted TH(2) polarization in memory CD4 cells. Ovalbumin immunization of mice transgenic for an ovalbumin receptor (OT-II mice) confirmed a marked increase in T cell BH(4) in vivo. These studies identify a previously unidentified consequence of T cell activation, promoting BH(4) levels, NO production, and modulating T cell cytokine production. 相似文献