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401.
Thein M Cheng A Khanna P Zhang C Park EJ Ahmed D Goodrich CJ Asphahani F Wu F Smith NB Dong C Jiang X Zhang M Xu J 《Biosensors & bioelectronics》2011,27(1):25-33
We developed a new instrumental method by which human melanoma cells (LU1205) are sonoporated via radiation pressures exerted by highly-confined ultrasonic waves produced by high lateral-resolution ultrasonic micro-transducer arrays (UMTAs). The method enables cellular-level site-specific sonoporation within the cell monolayer due to UMTAs and can be applicable in the delivery of drugs and gene products in cellular assays. In this method, cells are seeded on the biochip that employs UMTAs for high spatial resolution and specificity. UMTAs are driven by 30-MHz sinusoidal signals and the resulting radiation pressures induce sonoporation in the targeted cells. The sonoporation degree and the effective lateral resolution of UMTAs are determined by performing fluorescent microscopy and analysis of carboxylic-acid-derivatized CdSe/ZnS quantum dots passively transported into the cells. Models representing the transducer-generated ultrasound radiation pressure, the ultrasound-inflicted cell membrane wound, and the transmembrane transport through the wound are developed to determine the ultrasound-pressure-dependent wound size and enhanced cellular uptake of nanoparticles. Model-based calculations show that the effective wound size and cellular uptake of nanoparticles increase linearly with increasing ultrasound pressure (i.e., at applied radiation pressures of 0.21, 0.29, and 0.40 MPa, the ultrasound-induced initial effective wound radii are 150, 460, and 650 nm, respectively, and the post-sonoporation intracellular quantum-dot concentrations are 7.8, 22.8, and 29.9 nM, respectively) and the threshold pressure required to induce sonoporation in LU1205 cells is ~0.12 MPa. 相似文献
402.
Fu Lijun An Xinli Li Dong Zhou Lijian Tian Yun Zheng Tianling 《World journal of microbiology & biotechnology》2011,27(12):2949-2956
The bacterium BS02 which is closely related to the genus Vibrio sp. and capable of inhibiting the toxic dinoflagellate Alexandrium tamarense was isolated from a mangrove area in Zhangjiangkou, Fujian Province, China. The bacterium was not species-specific since
it displayed varying degrees of lysing activities against eight of the eighteen algae tested. There was a close interaction
between initial bacterial and A. tamarense cell densities, indicating that algal growth was prompted at low bacterial concentrations, while the number of the alga cells
was reduced at high concentrations. Alga-lysing characterization of Vibrio sp. BS02 suggested that the alga-lysing substance was extracellularly produced, less than 500 in molecular weight, as well
as non proteinaceous, stable under wide range of temperature and pH conditions, UV radiation, repeated freezing and thawing
and heavy metal treatments. These findings suggested that BS02 could play an important role in controlling harmful algal blooms. 相似文献
403.
The world heritage of Huangshan is located in the east-central China. In order to obtain a better overview of biodiversity
in Huangshan, we investigated the diversity of arbuscular mycorrhizal fungi in the soil of Huangshan. Forty-two rhizosphere
soil samples were collected and 989 arbuscular mycorrhizal fungal spore samples were obtained using the wet-sieving method.
Twenty-five species of arbuscular mycorrhizal fungi were identified from the collections. The species were of the genera Acaulospora (6 species), Entrophospora (1 species), Glomus (16 species) and Scutellospora (2 species). Acaulospora and Glomus were dominant at the study site. The arbuscular mycorrhizal fungi spore density ranged from 45 to 3,250 per 100 g soil (average
839), and the species richness of arbuscular mycorrhizal fungi ranged from 1 to 9 (average 4.2) per soil sample. Shannon–Wiener
index and Simpson’s index were calculated to evaluate the arbuscular mycorrhizal fungal diversity. The diversity of arbuscular
mycorrhizal fungal community in the subtropical forest of Huangshan may be the result of mutual selection between arbuscular
mycorrhizal fungi and the ecological environment. 相似文献
404.
Effects of pH and ORP on microbial ecology and kinetics for hydrogen production in continuously dark fermentation 总被引:1,自引:0,他引:1
The microbial structure and kinetic characteristics of the hydrogen producing strains in two fermentative continuous stirred-tank reactors (CSTRs) were studied by controlling pH and oxidation and reduction potential (ORP). The fluorescence in situ hybridization (FISH) tests were conducted to investigate the fermentative performance of Clostridium histolyticum (C. histolyticum), Clostridium lituseburense (C. lituseburense) and Enterobacteriaceae. The experimental results showed that in ethanol-type reactor 1#, the relative abundance of the strains was 48%, 30% and 22%. Comparatively, the relative abundance in butyric acid-type reactor 2# was 24%, 55% and 19% with butyric acids and hydrogen as the main products. The kinetic results indicated that the hydrogen yield coefficients YP/X in both reactors were 8.357 and 5.951 l-H2/g, while the coefficients of the cellular yield were 0.0268 and 0.0350 g-Cell/g, respectively. At the same biomass, the hydrogen yield in ethanol-type reactors was more than that in butyric acid reactors. However, the cellular synthesis rate in ethanol-type reactors was low when the same carbon source was used. 相似文献
405.
Gielis JF Lin JY Wingler K Van Schil PE Schmidt HH Moens AL 《Free radical biology & medicine》2011,50(7):765-776
The homodimeric flavohemeprotein endothelial nitric oxide synthase (eNOS) oxidizes l-arginine to l-citrulline and nitric oxide (NO), which acutely vasodilates blood vessels and inhibits platelet aggregation. Chronically, eNOS has a major role in the regulation of blood pressure and prevention of atherosclerosis by decreasing leukocyte adhesion and smooth muscle proliferation. However, a disturbed vascular redox balance results in eNOS damage and uncoupling of oxygen activation from l-arginine conversion. Uncoupled eNOS monomerizes and generates reactive oxygen species (ROS) rather than NO. Indeed, eNOS uncoupling has been suggested as one of the main pathomechanisms in a broad range of cardiovascular and pulmonary disorders such as atherosclerosis, ventricular remodeling, and pulmonary hypertension. Therefore, modulating uncoupled eNOS, in particular eNOS-dependent ROS generation, is an attractive therapeutic approach to preventing and/or treating cardiopulmonary disorders, including protective effects during cardiothoracic surgery. This review provides a comprehensive overview of the pathogenetic role of uncoupled eNOS in both cardiovascular and pulmonary disorders. In addition, the related therapeutic possibilities such as supplementation with the eNOS substrate l-arginine, volatile NO, and direct NO donors as well as eNOS modulators such as the eNOS cofactor tetrahydrobiopterin and folic acid are discussed in detail. 相似文献
406.
Horváth B Yeun LH Domonkos A Halász G Gobbato E Ayaydin F Miró K Hirsch S Sun J Tadege M Ratet P Mysore KS Ané JM Oldroyd GE Kaló P 《Molecular plant-microbe interactions : MPMI》2011,24(11):1345-1358
Legumes form endosymbiotic associations with nitrogen-fixing bacteria and arbuscular mycorrhizal (AM) fungi which facilitate nutrient uptake. Both symbiotic interactions require a molecular signal exchange between the plant and the symbiont, and this involves a conserved symbiosis (Sym) signaling pathway. In order to identify plant genes required for intracellular accommodation of nitrogen-fixing bacteria and AM fungi, we characterized Medicago truncatula symbiotic mutants defective for rhizobial infection of nodule cells and colonization of root cells by AM hyphae. Here, we describe mutants impaired in the interacting protein of DMI3 (IPD3) gene, which has been identified earlier as an interacting partner of the calcium/calmodulin-dependent protein, a member of the Sym pathway. The ipd3 mutants are impaired in both rhizobial and mycorrhizal colonization and we show that IPD3 is necessary for appropriate Nod-factor-induced gene expression. This indicates that IPD3 is a member of the common Sym pathway. We observed differences in the severity of ipd3 mutants that appear to be the result of the genetic background. This supports the hypothesis that IPD3 function is partially redundant and, thus, additional genetic components must exist that have analogous functions to IPD3. This explains why mutations in an essential component of the Sym pathway have defects at late stages of the symbiotic interactions. 相似文献
407.
Maintenance of calcium (Ca) balance in the uterus is critically important for many physiological functions, including smooth muscle contraction during embryo implantation. Ca transport genes, i.e., transient receptor potential cation channel subfamily V members 5/6 (TRPV5/6), calbindins, plasma membrane Ca(2+)-ATPase 1 (PMCA1), and NCX1/NCKX3, may play roles in the uterus for Ca transport and reproductive function. Although these Ca transport genes may have a role in Ca metabolism, their role(s) and molecular mechanisms require further elucidation. In this review, we highlight the expression and regulation of Ca transport genes in the uterus to clarify their potential role(s). Since Ca transport genes are abundantly expressed in reproductive tissues in a distinct manner, they may be involved in specific uterine functions including fetal implantation, Ca homeostasis, and endometrial cell production. 相似文献
408.
An H Kim NJ Jung JW Jang H Park JW Suh YG 《Bioorganic & medicinal chemistry letters》2011,21(21):6297-6300
Design, synthesis and insight into the structure-activity relationship (SAR) of 1,3-disubstituted indazoles as novel HIF-1 inhibitors are described. In particular, the substituted furan moiety on indazole skeleton as well as its substitution pattern turns out crucial for the high HIF-1 inhibition. 相似文献
409.
Nishimoto S Vu AT Naselaris T Benjamini Y Yu B Gallant JL 《Current biology : CB》2011,21(19):1641-1646
Quantitative modeling of human brain activity can provide crucial insights about cortical representations [1, 2] and can form the basis for brain decoding devices [3-5]. Recent functional magnetic resonance imaging (fMRI) studies have modeled brain activity elicited by static visual patterns and have reconstructed these patterns from brain activity [6-8]. However, blood oxygen level-dependent (BOLD) signals measured via fMRI are very slow [9], so it has been difficult to model brain activity elicited by dynamic stimuli such as natural movies. Here we present a new motion-energy [10, 11] encoding model that largely overcomes this limitation. The model describes fast visual information and slow hemodynamics by separate components. We recorded BOLD signals in occipitotemporal visual cortex of human subjects who watched natural movies and fit the model separately to individual voxels. Visualization of the fit models reveals how early visual areas represent the information in movies. To demonstrate the power of our approach, we also constructed a Bayesian decoder [8] by combining estimated encoding models with a sampled natural movie prior. The decoder provides remarkable reconstructions of the viewed movies. These results demonstrate that dynamic brain activity measured under naturalistic conditions can be decoded using current fMRI technology. 相似文献
410.
Grädler U Fuchss T Ulrich WR Boer R Strub A Hesslinger C Anézo C Diederichs K Zaliani A 《Bioorganic & medicinal chemistry letters》2011,21(14):4228-4232
Inducible arginine oxidation and subsequent NO production by correspondent synthase (iNOS) are important cellular answers to proinflammatory signals. Prolonged NO production has been proved in higher organisms to cause stroke or septic shock. Several classes of potent NOS inhibitors have been reported, most of them targeting the arginine binding site of the oxygenase domain. Here we disclose the SAR and the rational design of potent and selective iNOS inhibitors which may be useful as anti-inflammatory drugs. 相似文献