全文获取类型
收费全文 | 349篇 |
免费 | 18篇 |
出版年
2023年 | 3篇 |
2021年 | 1篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 13篇 |
2017年 | 8篇 |
2016年 | 10篇 |
2015年 | 18篇 |
2014年 | 13篇 |
2013年 | 14篇 |
2012年 | 11篇 |
2011年 | 22篇 |
2010年 | 8篇 |
2009年 | 13篇 |
2008年 | 14篇 |
2007年 | 18篇 |
2006年 | 14篇 |
2005年 | 9篇 |
2004年 | 22篇 |
2003年 | 10篇 |
2002年 | 22篇 |
2001年 | 12篇 |
2000年 | 6篇 |
1999年 | 6篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 6篇 |
1991年 | 7篇 |
1990年 | 7篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 11篇 |
1986年 | 9篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 7篇 |
1981年 | 1篇 |
1980年 | 4篇 |
1979年 | 9篇 |
1978年 | 5篇 |
1977年 | 4篇 |
1972年 | 2篇 |
1952年 | 1篇 |
1937年 | 1篇 |
排序方式: 共有367条查询结果,搜索用时 328 毫秒
1.
The aim of this study was to examine the effect of treating of chromium(III) and iron(III) and their combinations on Herpes Simplex Virus type 1 (HSV-1) and Bovine Viral Diarrhoea virus (BVDV) replication. The antiviral efficacies of chromium(III) and iron(III) on HSV-1 and BVDV were evaluated using Real Time PCR method. Moreover, the cytotoxicity of these microelements was examined using the MTT reduction assay. The IC50 (50% inhibiotory concentration) for the chromium chloride was 1100 μM for Hep-2 cells and 1400 μM for BT cells. The IC50 for the iron chloride was 1200 μM for Hep-2 cells and more than1400 μM for BT cells. The concentration-dependent antiviral activity of chromium chloride and iron chloride against HSV-1 and BVDV viruses was observed. In cultures simultaneously treated with (1) 200 μM of CrCl3 and 1000 μM of FeCl3, (2) 1000 μM of CrCl3 and 200 μM of FeCl3, (3) 400 μM of CrCl3 and 800 μM of FeCl3, (4) 800 μM of CrCl3 and 400 μM of FeCl3 a decrease in number of DNA or RNA copies was observed compared with control cells and cells incubated with chromium(III) and iron(III) used separately. The synergistic antiviral effects were observed for chromium(III) and iron(III) against HSV-1 and BVDV. 相似文献
2.
Adherent granulocytes secrete a granulocyte factor (GF). This factor stimulates hemopoiesis in irradiated mice. The target cell for this hemopoiesis-regulating GF action is probably T lymphocyte. The results indicate that the target cell is hydrocortisone- and cyclophosphamide-sensitive and prove that granulocytes stimulate hemopoiesis in irradiated mice via secreted GF. 相似文献
3.
4.
K Koz?owska J M Witkowski M Zarzeczna M Cichorek 《Folia histochemica et cytobiologica / Polish Academy of Sciences, Polish Histochemical and Cytochemical Society》1999,37(3):173-177
A comparison of the expression of P-glycoprotein (Pgp) was performed in two forms of hamster transplantable melanomas of common origin, but differing in growth rates and levels of differentiation. The expression of P-glycoprotein in plasma membranes of these two forms of melanomas was estimated by the western blot analysis and the transport activity of the Pgp compared by flow cytometry. It was observed that a spontaneous alteration in the original melanotic melanoma leading to a formation of the amelanotic form characterized by higher growth rate, greater anaplasticity and leading to the animals' death after a shorter time from inoculation, was accompanied by a decrease in the Pgp expression and activity, due to simultaneous appearance of a small population of amelanotic cells with high Pgp expression and activity, and disappearance of this activity from the major population. It is possible, that the activity of Pgp in the melanoma cell membranes reflects the degree of cell differentiation. 相似文献
5.
6.
Vittorio Canale Anna Partyka Rafał Kurczab Martyna Krawczyk Tomasz Kos Grzegorz Satała Bartłomiej Kubica Magdalena Jastrzębska-Więsek Anna Wesołowska Andrzej J. Bojarski Piotr Popik Paweł Zajdel 《Bioorganic & medicinal chemistry》2017,25(10):2789-2799
A novel series of arylsulfonamide derivatives of (aryloxy)propyl piperidines was designed to obtain potent 5-HT7R antagonists. Among the compounds evaluated herein, 3-chloro-N-{1-[3-(1,1-biphenyl-2-yloxy)2-hydroxypropyl]piperidin-4-yl}benzenesulfonamide (25) exhibited antagonistic properties at 5-HT7R and showed selectivity over selected serotoninergic and dopaminergic receptors, as well as over serotonin, noradrenaline and dopamine transporters. Compound 25 demonstrated significant antidepressant-like activity in the forced swim test (0.625–2.5 mg/kg, i.p.) and in the tail suspension test (1.25 mg/kg, i.p.), augmented the antidepressant effect of inactive doses of escitalopram (selective serotonin reuptake inhibitor) and bupropion (dopamine reuptake inhibitor) in the FST in mice, and similarly to SB-269970, exerted pro-cognitive properties in the novel object recognition task in cognitively unimpaired conditions in rats (0.3 mg/kg, i.p.). Such an extended pharmacological profile, especially the augmentation effect of the identified 5-HT7R antagonist on SSRI activity, seems promising regarding the complexity of affective disorders and potentially improved outcomes, including mnemonic performance. 相似文献
7.
A proline iminopeptidase (EC. 3.4.11.5) was isolated from shoots of 3 day old seedlings. The purification procedure consisted
of 5 steps: acid precipitation, gel filtration on Sephadex G-200, ion-exchange chromatography on Sepharose CL 6B, twice repeated
hydrophoic chromatography on Phenyl-Sepharose HP. The enzyme was purified 404.8-fold, with the specific activity of 8.5 units
mg−1 of protein with recovery yield of 3%. The purified enzyme had a molecular mass of 225 kDa estimated by gel filtration and
55.4 kDa by SDS PAGE. This indicates that native enzyme is composed of four subunits. The enzyme was specific for proline
β-naphtylamide among various amino acid β-naphtylamides.
An optimal activity was observed at 37 °C at pH 7.75. The enzyme was thermostable up to 37 °C for 30 min. The enzyme was strongly
inhibited by pHMB, E-64, heavy metal ions and partially by PMSF, DFP. The results suggest that cysteine and serine residues
may participate in the enzyme activity. 相似文献
8.
M. St?pien-S?odkowska K. Ficek J. Eider A. Leońska-Duniec A. Maciejewska-Kar?owska M. Sawczuk A. Zar?bska Z. Jastrz?bski A. Grenda K. Kotarska P. Ci?szczyk 《Biology of sport / Institute of Sport》2013,30(1):57-60
Objectives
The aim of this study was to examine the association of +1245G/T polymorphisms in the COL1A1 gene with ACL ruptures in Polish male recreational skiers in a case-control study.Methods
A total of 138 male recreational skiers with surgically diagnosed primary ACL ruptures, all of whom qualified for ligament reconstruction, were recruited for this study. The control group comprised 183 apparently healthy male skiers with a comparable level of exposure to ACL injury, none of whom had any self-reported history of ligament or tendon injury. DNA samples extracted from the oral epithelial cells were genotyped for the +1245G/T polymorphisms using real-time PCR method.Results
Genotype distributions among cases and controls conformed to Hardy-Weinberg equilibrium (p = 0.2469 and p = 0.33, respectively). There was a significant difference in the genotype distribution between skiers and controls (p = 0.045, Fisher''s exact test). There was no statistical difference in allele distribution: OR 1.43 (0.91-2.25), p = 0.101 (two-sided Fisher''s exact test).Conclusions
The risk of ACL ruptures was around 1.43 times lower in carriers of a minor allele G as compared to carriers of the allele T. 相似文献9.
Dariusz Czaprowski Justyna Leszczewska Aleksandra Kolwicz Paulina Paw?owska Agnieszka K?dra Piotr Janusz Tomasz Kotwicki 《PloS one》2013,8(8)
The aim of the study was to evaluate changes in hamstring flexibility in 120 asymptomatic children who participated in a 6-week program consisting of one physiotherapy session per week and daily home exercises. The recruitment criteria included age (10–13 years), no pain, injury or musculoskeletal disorder throughout the previous year, physical activity limited to school sport. Subjects were randomly assigned to one of the three groups: (1) post-isometric relaxation – PIR (n = 40), (2) static stretch combined with stabilizing exercises – SS (n = 40) and (3) stabilizing exercises – SE (n = 40). Hamstring flexibility was assessed with straight leg raise (SLR), popliteal angle (PA) and finger-to-floor (FTF) tests. The examinations were conducted by blinded observers twice, prior to the program and a week after the last session with the physiotherapist. Twenty-six children who did not participate in all six exercise sessions with physiotherapists were excluded from the analysis. The results obtained by 94 children were analyzed (PIR, n = 32; SS, n = 31; SE, n = 31). In the PIR and SS groups, a significant (P<0.01) increase in SLR, PA, FTF results was observed. In the SE group, a significant (P<0.001) increase was observed in the SLR but not in the PA and FTF (P>0.05). SLR result in the PIR and SS groups was significantly (P<0.001) higher than in the SE group. As far as PA results are concerned, a significant difference was observed only between the SS and SE groups (P = 0.014). There were no significant (P = 0.15) differences regarding FTF results between the three groups. Post-isometric muscle relaxation and static stretch with stabilizing exercises led to a similar increase in hamstring flexibility and trunk forward bend in healthy 10–13-year-old children. The exercises limited to straightening gluteus maximus improved the SLR result, but did not change the PA and FTF results. 相似文献
10.
The structure of a two-dimensional film formed by adsorbed polymer chains was studied by means of Monte Carlo simulations. The polymer chains were represented by linear sequences of lattice beads and positions of these beads were restricted to vertices of a two-dimensional square lattice. Two different Monte Carlo methods were employed to determine the properties of the model system. The first was the random sequential adsorption (RSA) and the second one was based on Monte Carlo simulations with a Verdier-Stockmayer sampling algorithm. The methodology concerning the determination of the percolation thresholds for an infinite chain system was discussed. The influence of the chain length on both thresholds was presented and discussed. It was shown that the RSA method gave considerably lower thresholds for longer chains. This behavior can be explained by a different pool of chain conformations used in the calculations in both methods under consideration. Figure
The percolation cluster (in red) in the system consisting of long flexible chains 相似文献