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81.
Molecular and Cellular Biochemistry - Active neutrophils participate in innate and adaptive immune responses through various mechanisms, one of the most important of which is the formation and...  相似文献   
82.
MyTH4-FERM (MF) myosins evolved to play a role in the creation and function of a variety of actin-based membrane protrusions that extend from cells. Here we performed an analysis of the MF myosins, Myo7A, Myo7B, and Myo10, to gain insight into how they select for their preferred actin networks. Using enterocytes that create spatially separated actin tracks in the form of apical microvilli and basal filopodia, we show that actin track selection is principally guided by the mode of oligomerization of the myosin along with the identity of the motor domain, with little influence from the specific composition of the lever arm. Chimeric variants of Myo7A and Myo7B fused to a leucine zipper parallel dimerization sequence in place of their native tails both selected apical microvilli as their tracks, while a truncated Myo10 used its native antiparallel coiled-coil to traffic to the tips of filopodia. Swapping lever arms between the Class 7 and 10 myosins did not change actin track preference. Surprisingly, fusing the motor-neck region of Myo10 to a leucine zipper or oligomerization sequences derived from the Myo7A and Myo7B cargo proteins USH1G and ANKS4B, respectively, re-encoded the actin track usage of Myo10 to apical microvilli with significant efficiency.  相似文献   
83.
A group of 1,3-diarylurea derivatives, possessing a methylsulfonyl pharmacophore at the para-position of the N-1 phenyl ring, in conjunction with a N-3 substituted-phenyl ring (4-F, 4-Cl, 4-Me, 4-OMe), were designed and synthesized for evaluation as selective cyclooxygenase-2 (COX-2) inhibitors. In vitro COX-1/COX-2 isozyme inhibition structure-activity studies identified 1-(4-methylsulfonylphenyl)-3-(4-methoxyphenyl) urea (4e) as a potent COX-2 inhibitor (IC(50)=0.11 microM) with a high COX-2 selectivity index (SI=203.6) comparable to the reference drug celecoxib (COX-2 IC(50)=0.06 microM; COX-2 SI=405). The structure-activity data acquired indicate that the urea moiety constitutes a suitable scaffold to design new acyclic 1,3-diarylurea derivatives with selective COX-2 inhibitory activity.  相似文献   
84.
85.
Contradictory results were reported on the effect of fat mass- and obesity-associated (FTO) gene and anthropometric measurements on breast cancer (BC). This study aimed to assess the interactions between rs9939609 polymorphism of FTO gene, anthropometric indices and BC risk in Iranian women. This case-control study was performed on 540 women including 180 women with BC and 360 healthy women in Tehran, Iran. Physical activity and dietary intakes were assessed by validated questionnaires. Data on sociodemographic and pathologic factors of the participants as well as their blood samples were collected. The rs9939609 FTO gene polymorphism was genotyped using the tetra-primer amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR). No significant association was found between BC and risk allele of FTO rs9939609 polymorphism after adjustments for the confounders. However, there was a significant association between rs9939609 polymorphism risk allele and BC risk in females with overweight, even after adjusting for age, family history of BC, abortion, BMI and the number of pregnancies (P < .05). The association was disappeared after further adjustments for lifestyle factors including smoking, alcohol consumption, calorie and macronutrients intake, and physical activity. The FTO gene polymorphism was associated with the risk of BC in overweight individuals. This association was influenced by environmental factors including diet, alcohol consumption and smoking. Future studies are required to confirm the association between the FTO gene and BC in overweight females and to identify the underlying mechanisms.  相似文献   
86.
The mobility of heavy metals in contaminated soils is dependent on the kinetics release from soils. Metal extraction over time is commonly used to distinguish two or more fractions of metal based on differences of extraction or release rates. Kinetic studies using 0.01 M CaCl2, 0.01 M malic acid, and 0.01 M EDTA extractions were performed to characterize nickel (Ni) and lead (Pb) kinetic release in 10 contaminated calcareous soils. Proportions of Ni and Pb extracted with EDTA were higher than when using malic acid and CaCl2, respectively. The release of Ni and Pb was characterized by an initial fast rate followed by a slower rate and could best be described by a two first-order reactions model with rate constants k1 and k2 and two metal pools: readily labile (Q 1) and less labile (Q 2). In an EDTA extractant, different Q1 /Q2 ratios for Ni and Pb were observed, indicating binding energies to soil constituents is not comparable. The k1 of the model for Ni (average of 10 soils: 0.2204 h?1 and 0.2359 h?1 for 0.01 M CaCl2 and 0.01 EDTA, respectively) was higher than Pb (0.1044 h?1 and 0.1631 h?1 for 0.01 M CaCl2 and 0.01 M EDTA, respectively), indicating a higher potential of Ni for leaching and groundwater contamination in contaminated calcareous soils. Relationships between the fraction of Ni and Pb determined with the two first-order reactions model and the soil composition and Pb fractions were established. The results indicated that the efficiency of the extractions Ni and Pb from soils depends both on the Ni and Pb content and soil composition. Overall, the results indicated that the use of a 0.01 M malic acid washing solution would be preferred in the field condition.  相似文献   
87.
Studying the interaction of some atmospheric gases (H2O, HCN, NH3, SO3 and H2S) with 3PT oligomers is important in the development of polymeric sensors for gas detection. In the present study, we studied the relaxed geometries, interaction energies, charge analysis, HOMO–LUMO orbital analysis, and UV–vis spectra of all interacted systems using first-principles density functional theory (DFT). All these analyses indicated the potential of polythiophene as an inexpensive polymeric sensor for the analytes mentioned. Interaction energy values of ?19.90, ?19.66, ?14.01, ?8.70, and ?4.76 kJ mol?1 were achieved for adsorption of SO3, H2O, NH3, HCN, and H2S on 3PT, respectively. Consequently, clarification of their physical parameters became the major focus of this study.  相似文献   
88.
Two-spotted spider mite, Tetranychus urticae Koch is the major pest of various plants worldwide. Now the control is dependent on the use of chemical pesticides. Plant compounds are recently known as biopesticides. Essential oil of Elettaria cardamomum was researched on repellent and oviposition inhibition of T. urticae. The LC50 values of fumigant toxicity of this oil on adults and eggs of the two spotted spider mite were 7.26 and 8.82?μL/L air, respectively. Also LT50 value of essential oil at 45?μL/L air was 23.86?h and LT50 value of essential oil at 60?μL/L air was 9.01?h. In addition, different concentrations of the essential oil of E. cardamomum significantly affected oviposition deterrence and repellency of adults. The results of this study indicated that essential oil of E. cardamomum may be considered as a biopesticide to control two spotted spider mites.  相似文献   
89.
Recent developments in bone tissue engineering have paved the way for more efficient and cost-effective strategies. Additionally, utilization of autologous sources has been considered very desirable and is increasingly growing. Recently, activated platelet rich plasma (PRP) has been widely used in the field of bone tissue engineering, since it harbours a huge number of growth factors that can enhance osteogenesis and bone regeneration. In the present study, the osteogenic effects of PRP coated nanofibrous PES/PVA scaffolds on adipose-derived mesenchymal stem cells have been investigated. Common osteogenic markers were assayed by real time PCR. Alkaline phosphate activity, calcium deposition and Alizarin red staining assays were performed as well. The results revealed that the highest osteogenic differentiation occurred when cells were cultured on PRP coated PES/PVA scaffolds. Interestingly, direct application of PRP to culture media had no additive effects on osteogenesis of cells cultured on PRP coated PES/PVA scaffolds or those receiving typical osteogenic factors. The highest osteogenic effects were achieved by the simplest and most cost-effective method, i.e. merely by using PRP coated scaffolds. PRP coated PES/PVA scaffolds can maximally induce osteogenesis with no need for extrinsic factors. The major contribution of this paper to the current researches on bone regeneration is to suggest an easy, cost-effective approach to enhance osteogenesis via PRP coated scaffolds, with no additional external growth factors.  相似文献   
90.
Refugia are critical for the maintenance of biodiversity during the periods of Quaternary climatic oscillations. The long‐term persistence of refugial populations in a large continuous refugium has resulted in a homogenous pattern of genetic structure among populations, while highly structured evolutionary lineages characterize the restriction of refugial populations to smaller subrefugia. These mechanisms have resulted in the identification of hot spots of biodiversity within putative glacial refugia. We studied phylogeography of Potamon ibericum (Brachyura: Potamidae) in the drainages of the western Caucasus biodiversity hot spot (i.e., Colchis and the Caucasus) to infer spatial genetic structure and potential refugia for a freshwater crab in this region. These areas have traditionally considered as a refugium due to the presence of Tertiary relict species. We integrated population genetic data and historical demographic analysis from cytochrome oxidase subunit I sequences and paleoclimatic data from species distribution modeling (SDM). The results revealed the lack of phylogeographic structure and provided evidence for demographic expansion. The SDM presented a rather homogenous and large refugium that extended from northeast Turkey to Colchis during the last glacial period. In contrast to these findings, previous phylogeographic study on P. ibericum of the eastern Caucasus biodiversity hot spot (i.e., Hyrcania) identified multiple independent refugia. By combining these results, we explain the significance of this important western Palearctic hot spot of biological diversity in shaping the geographic distribution of intraspecific genetic diversity in a freshwater taxon.  相似文献   
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