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891.
While various approaches exist to study protein localization, it is still a challenge to predict where proteins localize. Here, we consider a mechanistic viewpoint for membrane localization. Taking into account the steps for the folding pathway of α-helical membrane proteins and relating biophysical parameters to each of these steps, we create a score capable of predicting the propensity for membrane localization and call it FP(3)mem. This score is driven from the principal component analysis (PCA) of the biophysical parameters related to membrane localization. FP(3)mem allows us to rationalize the colocalization of a number of channel proteins with the Cav1.2 channel by their fewer propensities for membrane localization. 相似文献
892.
Aghamaali MR Jafarian V Sariri R Molakarimi M Rasti B Taghdir M Sajedi RH Hosseinkhani S 《The protein journal》2011,30(8):566-574
A comparison of the two most famous groups of calcium-regulated photoproteins, cnidarians and ctenophores, showed unexpectedly
high degree of structural similarity regardless of their low sequence identity. It was suggested these photoproteins can play
an important role in understanding the structural basis of bioluminescence activity. Based on this postulate, in this study
the cDNA of mnemiopsin from luminous ctenophore Mnemiopsis
leidyi was cloned, expressed, purified and sequenced. The purified cDNA, with 621 base pairs, coded a 206 residues protein. Sequence
of mnemiopsin showed 93.5 and 51% similarity to other ctenophore proteins and cnidarians, respectively. The cDNA encoding
apo-mnemiopsin of M. leidyi was expressed in Escherichia coli. The purified apo-protein showed a single band on SDS-PAGE (molecular weight ~27 kDa). A semi-synthetic mnemiopsin was prepared
using coelenterazine and EDTA and its luminescence activity was measured in the presence of CaCl2. The results showed an optimum pH of 9.0 and lower calcium sensitivity compared to aequorin. Comparison of amino acid residues
in substrate binding site indicated that binding pocket of ctenophores contains less aromatic residues than cnidarians. This
can lead to a decline in the number of stacking interactions between substrate and protein which can affect the stability
of coelenterazine in binding cavity. Structural comparison of photoproteins with low sequence identity and high 3D structural
similarity, can present a new insight into the mechanism of light emission in photoproteins. 相似文献
893.
894.
Arjomandzadegan M Owlia P Ranjbar R Farazi AA Sofian M Sadrnia M Ghaznavi-Rad E Surkova LK Titov LP 《Acta microbiologica et immunologica Hungarica》2011,58(1):51-63
Isoniazid (INH) is a central component of drug regimens used worldwide to treat tuberculosis. In respect to high GC content of Mycobacterium tuberculosis, nonsynonymous mutations are dominant in this group. In this study a collection of 145 M. tuberculosis isolates was used to evaluate the conferring mutations in nucleotide 1388 of katG gene (KatG463) in resistance to isoniazid. A PCR-RFLP method was applied in comparison with DNA sequencing and anti-mycobacterial susceptibility testing. From all studied patients, 98 (67.6%) were men, 47 (32.4%) were women, 3% were <15 and 9% were >65 years old; male to female ratio was 1:2.4. PCR result of katG for a 620-bp amplicon was successful for all purified M. tuberculosis isolates and there was no positive M. tuberculosis culture with PCR negative results (100% specificity). Subsequent PCR RFLP of the katG identified mutation at KatG463 in 33.3%, 57.8% and 59.2% of our clinically susceptible, multidrug resistant TB (MDR) and extensively drug resistant (XDR) isolates, respectively. Strains of H37Rv and Academic had no any mutations in this codon. M. bovis was used as a positive control for mutation in KatG463. Automated DNA sequencing of the katG amplicon from randomly selected INH-susceptible and resistant isolates verified 100% sequence accuracy of the point mutations detected by PCR-RFLP. We concluded that codon 463 was a polymorphic site that is associated to INH resistance (a missense or "quiet" mutation). RFLP results of katG amplicons were identical to those of sequence method. Our PCR-RFLP method has a potential application for rapid diagnosis of M. tuberculosis with a high specificity. 相似文献
895.
Methane production from two types of wool textile wastes (TW1 and TW2) was investigated. To improve the digestibility of these textiles, different pretreatments were applied, and comprised thermal treatment (at 120 °C for 10 min), enzymatic hydrolysis (using an alkaline endopeptidase at different levels of enzymatic loading, at 55 °C for 0, 2, and 8 h), and a combination of these two treatments. Soluble protein concentration and sCOD (soluble chemical oxygen demand) were measured to evaluate the effectivity of the different pretreatment conditions to degrade wool keratin. The sCOD as well as the soluble protein content had increased in both textile samples in comparison to untreated samples, as a response to the different pretreatments indicating breakdown of the wool keratin structure.The combined treatments and the thermal treatments were further evaluated by anaerobic batch digestion assays at 55 °C. Combined thermal and enzymatic treatment of TW1 and TW2 resulted in methane productions of 0.43 N m3/kg VS and 0.27 N m3/kg VS, i.e., 20 and 10 times higher yields, respectively, than that gained from untreated samples. The application of thermal treatment by itself was less effective and resulted in increasing the methane production by 10-fold for TW1 and showing no significant improvement for TW2. 相似文献
896.
Aliakbar Haddad-Mashadrizeh Ahmad Reza Bahrami Maryam M. Matin Mohammad Amin Edalatmanesh Alireza Zomorodipour Ali Fallah Mossa Gardaneh Naghmeh Ahmadian Kia Naser Sanjarmoosavi 《Cytotherapy》2013,15(8):951-960
Background aimsTherapeutic promises of adult stem cells have been overshadowed by an elicited immune response, low maintenance of implanted cells or concerns regarding their migration to non-target sites. These problems might be lessened by the use of immune privilege cells and tissues for implantation.MethodsIn this study, human adipose-derived mesenchymal stromal cells (hADMSCs) were stably transfected with a vector containing Turbo green fluorescent protein (GFP) and JRed, which allows tracing the cells after transplantation. Labeled hADMSCs were transplanted into the adult rat brain followed by assessment of their survival and migration during 6 months after transplantation.ResultsResults indicate that there were no postsurgical complications, and the animals thrived after transplantation. The lesions of the surgical process were remarkable at the first weeks, and a high number of transplanted cells were accumulated around them. Cell populations declined over time as they partly migrated away from the injection sites; nonetheless, they were detectable at each examination time point. Although the cells could survive and remain at the injection site for up to 6 months, some of them drifted to spleen, which is an indication of their ability to cross the blood-brain barrier.ConclusionsDespite the high survival rate of hADMSCs in the xenogenic condition, which is an ideal criterion in cell therapy, irregular migration tendency must be handled with caution. 相似文献
897.
Roya Khosravi Amin Javidanbardan Maryam Khatami Hooman Kaghazian Seyed Dawood Mousavi Nasab 《Preparative biochemistry & biotechnology》2013,43(7):686-694
AbstractIn mammalian cell culture technology, viral contamination is one of the main challenges; and, so far, various strategies have been taken to remove or inactivate viruses in the cell-line production process. The suitability and feasibility of each method are determined by different factors including effectiveness in target virus inactivation, maintaining recombinant protein stability, easiness—in terms of the process condition, cost-effectiveness, and eco-friendliness. In this research, Taguchi design-of-experiments (DOE) methodology was used to optimize a non-detergent viral inactivation method via considering four factors of temperature, time, pH, and alcohol concentration in an unbiased (orthogonal) fashion with low influence of nuisance factors. Herpes Simplex Virus-1 (HSV1) and Vero cell-line were used as models for enveloped viruses and cell-line, respectively. Examining the cytopathic effects (CPE) in different dilutions showed that pH (4), alcohol (15%), time (120?min), and temperature (25?°C) were the optimal points for viral inactivation. Evaluating the significance of each parameter in the HSV-1 inactivation using Taguchi and ANOVA analyses, the contributions of pH, alcohol, temperature and time were 56.5%, 19.2%, 12%, and 12%, respectively. Examining the impact of the optimal viral treatment condition on the stability of model recombinant protein-recombinant human erythropoietin, no destabilization was detected. 相似文献
898.
Mahnaz Taherianfard Marjan Davazdahemamy Manzarbanoo Shojaeifard Maryam Sharifi 《Journal of physiology and biochemistry》2013,69(1):141-145
Neurosteroids are modulators of neuronal function that may play important role in brain maturation. The aim of the present investigation was to study the effect of prenatal exposure to acute and chronic ethanol on brain progesterone, estradiol, and testosterone concentration on 10th and 15th days following egg incubation. Eggs were exposed to ethanol at 10 % in chronic treatment and 70 % in acute treatment. Progesterone, estradiol, and testosterone were assayed by radioimmunoassay method. It was shown that brain progesterone level was significantly decreased (P?<?0.05) in chronic ethanol group on embryonic day 10, but it was significantly decreased (P?<?0.05) in acute and chronic groups on embryonic day 15. Brain estradiol level was significantly increased (P?<?0.05) in chronic ethanol group on embryonic day 10, and it was decreased (P?<?0.05) in acute and chronic groups of ethanol on embryonic day 15. Brain testosterone was significantly increased (P?<?0.05) in acute and chronic ethanol-exposed groups on embryonic days 10 and 15. Our observations suggest that ethanol may modulate neurosteroid synthesis in the brain. 相似文献
899.
900.
Li Alemo Munters Maryam Dastmalchi Abram Katz Mona Esbj?rnsson Ingela Loell Balsam Hanna Maria Lidén H?kan Westerblad Ingrid E Lundberg Helene Alexanderson 《Arthritis research & therapy》2013,15(4):R83