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排序方式: 共有299条查询结果,搜索用时 15 毫秒
91.
Zhou B Ann DK Li X Kim KJ Lin H Minoo P Crandall ED Borok Z 《American journal of physiology. Cell physiology》2007,292(4):C1280-C1290
92.
93.
Mustapa MF Bell PC Hurley CA Nicol A Guénin E Sarkar S Writer MJ Barker SE Wong JB Pilkington-Miksa MA Papahadjopoulos-Sternberg B Shamlou PA Hailes HC Hart SL Zicha D Tabor AB 《Biochemistry》2007,46(45):12930-12944
Nonviral gene delivery vectors now show good therapeutic potential: however, detailed characterization of the composition and macromolecular organization of such particles remains a challenge. This paper describes experiments to elucidate the structure of a ternary, targeted, lipopolyplex synthetic vector, the LID complex. This consists of a lipid component, Lipofectin (L) (1:1 DOTMA:DOPE), plasmid DNA (D), and a dual-function, cationic peptide component (I) containing DNA condensation and integrin-targeting sequences. Fluorophore-labeled lipid, peptide, and DNA components were used to formulate the vector, and the stoichiometry of the particles was established by fluorescence correlation spectroscopy (FCS). The size of the complex was measured by FCS, and the sizes of LID, L, LD, and ID complexes were measured by dynamic light scattering (DLS). Fluorescence quenching experiments and freeze-fracture electron microscopy were then used to demonstrate the arrangement of the lipid, peptide, and DNA components within the complex. These experiments showed that the cationic portion of the peptide, I, interacts with the plasmid DNA, resulting in a tightly condensed DNA-peptide inner core; this is surrounded by a disordered lipid layer, from which the integrin-targeting sequence of the peptide partially protrudes. 相似文献
94.
Norouzi P Ganjali MR Daneshgar P Alizadeh T Mohammadi A 《Analytical biochemistry》2007,360(2):175-181
Fast continuous cyclic voltammetry was used as a detection method for penicillin V in a flow injection system. Additionally, a special computer-based numerical calculation method (using fast Fourier transformation) providing enhancement of the analyte signal and noise reduction is introduced here. During the measurements, the potential waveform (consisting of the potential steps of cleaning, stripping, and the potential ramp) was continuously applied to an Au disk microelectrode (12.5 microm in radius). In particular, the effects of accumulation potential, sweep rate, and delay time on the sensitivity and selectivity of the method were investigated. Eventually, the stripping time was found to be less than 300 ms, the detection limit of the method was 7.0x10(-12) M, and the associated relative standard deviation at 5.0x10(-6) M penicillin V was 2.3 for eight runs. 相似文献
95.
96.
Pilkington-Miksa MA Writer MJ Sarkar S Meng QH Barker SE Shamlou PA Hailes HC Hart SL Tabor AB 《Bioconjugate chemistry》2007,18(6):1800-1810
We have developed efficient synthetic routes to two hydrophobic amino acids, suitably protected for solid-phase peptide synthesis, and have successfully synthesized peptides containing these or other hydrophobic amino acids as spacers between a Lys16 moiety and an integrin-targeting motif. These peptides have in turn been used to formulate a range of lipopolyplex vectors with Lipofectin and plasmid DNA. The transfection efficiencies of these vectors and their aggregation behavior in buffers and in serum have been studied. We have shown that vectors containing peptides incorporating long linkers that are entirely hydrophobic are less efficient transfection agents. However, linkers of equivalent length that are in part hydrophobic show improved transfection properties, which is probably due to the improved accessibility of the integrin-binding motif. 相似文献
97.
Majid Eslami Bahman Yousefi Parviz Kokhaei Maral Hemati Zahra Rasouli Nejad Vahid Arabkari Afshin Namdar 《Journal of cellular physiology》2019,234(10):17127-17143
Colorectal cancer (CRC) remains one of the most common and deadly cancers. Intestinal gut microflora is important to maintain and contributes to several intestinal functions, including the development of the mucosal immune system, absorption of complex macromolecules, synthesis of amino acids/vitamins and the protection against pathogenic microorganisms. It is well known that the gut microbiota changes or dysbiosis may have an essential impact in the initiation and promotion of chronic inflammatory pathways and also have a profound different genetic and epigenetic alterations leading to dysplasia, clonal expansion, and malignant transformation. Probiotic bacteria has antitumor activity with various mechanisms such as nonspecific physiological and immunological mechanisms. This review evaluates the effects of microbiota and probiotics in clinical trials, in vitro and animal model studies that have explored how probiotic against cancer development and also discusses the possible immunomodulatory mechanisms. Several mechanisms alteration of the intestinal microflora; inactivation of cancerogenic compounds; competition with putrefactive and pathogenic microbiota; improvement of the host's immune response; antiproliferative effects via regulation of apoptosis and cell differentiation; fermentation of undigested food; inhibition of tyrosine kinase; reduces the enteropathogenic complications before and after colon cancer surgery and improve diarrhea and it's have been able to create the integrity of gut mucosal and have stimulatory effects on the systemic immune system and prevent the CRC metastasis. Research in clinical trials encouraging findings that support a role of probiotics in CRC prevention and improve the safety and effectiveness of cancer therapy even though additional clinical research is still necessary. 相似文献
98.
Plant and Soil - Dicranopteris linearis is a fern that accumulates unusually high concentrations (up to 0.3% dry weight) of rare earth elements (REEs) in China. Previously, we reported that D.... 相似文献
99.
Behnam Kamalidehghan Massoud Houshmand Fereydoun Kamalidehghan Narges Jafarzadeh Shahram Azari Sharifah Noor Akmal Rozita Rosli 《Cancer cell international》2012,12(1):1-15
Background
Breast cancer is one of the most common cancers among women throughout the world. Therefore, established cell lines are widely used as in vitro experimental models in cancer research.Methods
Two continuous human breast cell lines, designated MBC1 and MBC2, were successfully established and characterized from invasive ductal breast carcinoma tissues of Malaysian patients. MBC1 and MBC2 have been characterized in terms of morphology analysis, population doubling time, clonogenic formation, wound healing assay, invasion assay, cell cycle, DNA profiling, fluorescence immunocytochemistry, Western blotting and karyotyping.Results
MBC1 and MBC2 exhibited adherent monolayer epithelial morphology at a passage number of 150. Receptor status of MBC1 and MBC2 show (ER+, PR+, HER2+) and (ER+, PR-, HER2+), respectively. These results are in discordance with histopathological studies of the tumoral tissues, which were triple negative and (ER-, PR-, HER2+) for MBC1 and MBC2, respectively. Both cell lines were capable of growing in soft agar culture, which suggests their metastatic potential. The MBC1 and MBC2 metaphase spreads showed an abnormal karyotype, including hyperdiploidy and complex rearrangements with modes of 52–58 chromosomes per cell.Conclusions
Loss or gain in secondary properties, deregulation and specific genetic changes possibly conferred receptor changes during the culturing of tumoral cells. Thus, we hypothesize that, among heterogenous tumoral cells, only a small minority of ER+/PR+/HER2+ and ER+/PR-/HER2+ cells with lower energy metabolism might survive and adjust easily to in vitro conditions. These cell lines will pave the way for new perspectives in genetic and biological investigations, drug resistance and chemotherapy studies, and would serve as prototype models in Malaysian breast carcinogenesis investigations. 相似文献100.
The structural properties, NMR and NQR parameters in the pristine and silicon carbide (SiC) doped boron phosphide nanotubes
(BPNTs) were calculated using DFT methods (BLYP, B3LYP/6-31G*) in order to evaluate the influence of SiC-doped on the (4,4)
armchair BPNTs. Nuclear magnetic resonance (NMR) parameters including isotropic (CSI) and anisotropic (CSA) chemical shielding parameters for the sites of various 13C, 29Si, 11B, and 31P atoms and quadrupole coupling constant (C
Q
), and asymmetry parameter (η
Q
) at the sites of various 11B nuclei were calculated in pristine and SiC- doped (4,4) armchair boron phosphide nanotubes models. The calculations indicated that doping of 11B and 31P atoms by C and Si atoms had a more significant influence on the calculated NMR and NQR parameters than did doping of the
B and P atoms by Si and C atoms. In comparison with the pristine model, the SiC- doping in SiPCB model of the (4,4) armchair BPNTs reduces the energy gaps of the nanotubes and increases their electrical conductance. The NMR results showed that the
B and P atoms which are directly bonded to the C atoms in the SiC-doped BPNTs have significant changes in the NMR parameters
with respect to the B and P atoms which are directly bonded to the Si atoms in the SiC-doped BPNTs. The NQR results showed
that in BPNTs, the B atoms at the edges of nanotubes play dominant roles in determining the electronic behaviors of BPNTs.
Also, the NMR and NQR results detect that the Fig. 1b (SiPCB) model is a more reactive material than the pristine and the Fig. 1a (SiBCp) models of the (4,4) armchair BPNTs. 相似文献