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131.
A three dimensional (3D) gold (Au) nanodendrite network porous structure constructed by a simple electrochemical synthetic method has been presented, and its utility for sensitive electrochemical measurement was demonstrated in this study. The 3D nanodendrite network porous structure was constructed on a platinum surface through electrodeposition of Au under the presence of hydrogen bubbles generated from the same surface. Iodide, used as a co-reagent, played an important role in the construction of the nanodendrite network by preventing continual growth of Au into larger agglomerates as well as inhibiting coalescence of neighboring nanodendrites. An electrochemical sensor incorporating the structure was built and used to detect As(III) in ultra low concentration range. For the purpose of comparison, bare gold and gold nanoparticle-incorporated electrodes were also prepared. With the use of 3D nanodendrite network porous structure, a much more sensitive detection of As(III) was possible due to its large surface area. 相似文献
132.
133.
This study examined the important relationship between cystathionine γ-lyase (CSE) functionality and cysteine supply for normal growth and life span. Mice with a targeted deletion of the CSE gene (CSE-KO) were fed a cysteine-limited diet and their growth and survival patterns as well as levels of cysteine, homocysteine, glutathione, and hydrogen sulfide (H2S) were measured. CSE-KO mice fed a cysteine-limited diet exhibited growth retardation; decreased levels of cysteine, glutathione, and H2S; and increased plasma homocysteine level. However, histological examinations of liver did not reveal any abnormality and plasma levels of aspartate aminotransferase, alanine aminotransferase, and albumin were normal in these animals. No CSE-KO mice survived after 12 weeks of feeding with the cysteine-limited diet. Supplementation of H2S to the CSE-KO mice failed to reverse the aforementioned abnormalities. On the other hand, supplementation of cysteine in the drinking water of the CSE-KO mice significantly increased plasma cysteine and glutathione levels. This eventually led to an increase in body weight and rescued the animals from death. In conclusion, CSE is critical for cysteine biosynthesis through the transsulfuration pathway and the combination of CSE deficiency and lack of dietary cysteine supply would threaten life sustainability. 相似文献
134.
Microspheres of tramadol hydrochloride (TM) for oral delivery were prepared by complex coacervation method without the use
of chemical cross-linking agents such as glutaraldehyde to avoid the toxic reactions and other undesirable effects of the
chemical cross-linking agents. Alternatively, ionotropic gelation was employed by using sodium-tripolyphosphate as cross-linking
agent. Chitosan and gelatin B were used as polymer and copolymer, respectively. All the prepared microspheres were subjected
to various physicochemical studies, such as drug–polymer compatibility by thin layer chromatography (TLC) and Fourier transform
infrared (FTIR) spectroscopy, surface morphology by scanning electron microscopy, frequency distribution, drug entrapment
efficiency, in vitro drug release characteristics and release kinetics. The physical state of drug in the microspheres was determined by differential
scanning calorimetry (DSC) and X-ray diffractometry (XRD). TLC and FTIR studies indicated no drug–polymer incompatibility.
All the microspheres showed initial burst release followed by a fickian diffusion mechanism. DSC and XRD analysis indicated
that the TM trapped in the microspheres existed in an amorphous or disordered-crystalline status in the polymer matrix. From
the preliminary trials, it was observed that it may be possible to formulate TM microspheres by using biodegradable natural
polymers such as chitosan and gelatin B to overcome the drawbacks of TM and to increase the patient compliance. 相似文献
135.
Isotope-assisted vibrational circular dichroism (VCD) investigations have been used to probe the site specific local structure of an amyloid peptide for the first time. A seven residue peptide, NH2-KLVFFAE-COOH, which represents the Aβ(16–22) fragment of the Alzheimer’s amyloid β peptide, was used for these investigations. 13C labels were introduced separately at the carbonyl group of leucine (residue 17), alanine (residue 21) and also at both sites together. Since VCD spectra provide structure dependent signs, band shapes and frequencies, the isotope-assisted VCD spectroscopy revealed information on site specific secondary structure of the polypeptide. Isotope dilution VCD experiments provided a means to distinguish between parallel and anti-parallel nature of the β-sheet structure formed by the Aβ(16–22) fragment. The current results establish the usefulness of isotope-assisted VCD analysis in determining the site specific secondary structure of amyloid peptides. 相似文献
136.
Agrawal GK Job D Zivy M Agrawal VP Bradshaw RA Dunn MJ Haynes PA van Wijk KJ Kikuchi S Renaut J Weckwerth W Rakwal R 《Proteomics》2011,11(9):1559-1568
Given the essential role of proteomics in understanding the biology of plants, we are establishing a global plant proteomics organization to properly organize, preserve and disseminate collected information on plant proteomics. We call this organization 'International Plant Proteomics Organization (INPPO; http://www.inppo.com).' Ten initiatives of INPPO are outlined along with how to address them in multiple phases. As our vision is global, we sincerely hope the scientific communities around the world will come together to support and join INPPO. 相似文献
137.
138.
The emergence of drug resistance in M. tuberculosis undermines the efficacy of tuberculosis (TB) treatment in individuals and of TB control programs in populations. Multiple drug resistance is often attributed to sequential functional monotherapy, and standard initial treatment regimens have therefore been designed to include simultaneous use of four different antibiotics. Despite the widespread use of combination therapy, highly resistant M. tb strains have emerged in many settings. Here we use a stochastic birth-death model to estimate the probability of the emergence of multidrug resistance during the growth of a population of initially drug sensitive TB bacilli within an infected host. We find that the probability of the emergence of resistance to the two principal anti-TB drugs before initiation of therapy ranges from 10(-5) to 10(-4); while rare, this is several orders of magnitude higher than previous estimates. This finding suggests that multidrug resistant M. tb may not be an entirely "man-made" phenomenon and may help explain how highly drug resistant forms of TB have independently emerged in many settings. 相似文献
139.
Kim DM Yun NR Neupane GP Shin SH Ryu SY Yoon HJ Wie SH Kim WJ Lee CY Choi JS Yang TY 《PloS one》2011,6(8):e22731
Background
Scrub typhus is an infectious disease caused by Orientia tsutsugamushi. The differences in virulence of O. tsutsugamushi prototypes in humans are still unknown. We investigated whether there are any differences in the clinical features of the Boryoung and Karp genotypes.Methodology/Principal Findings
Patients infected with O. tsutsugamushi, as Boryoung and Karp clusters, who had visited 6 different hospitals in southwestern Korea were prospectively compared for clinical features, complications, laboratory parameters, and treatment responses. Infected patients in the Boryoung cluster had significantly more generalized weakness, eschars, skin rashes, conjunctival injection, high albumin levels, and greater ESR and fibrinogen levels compared to the Karp cluster. The treatment response to current antibiotics was significantly slower in the Karp cluster as compared to the Boryoung cluster.Conclusion
The frequency of occurrence of eschars and rashes may depend on the genotype of O. tsutsugamushi. 相似文献140.