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排序方式: 共有192条查询结果,搜索用时 10 毫秒
41.
Tuan Trinh Daniel Saliba Chenyi Liao Donatien deRochambeau Alexander Lee Prinzen Jianing Li Hanadi F. Sleiman 《Angewandte Chemie (International ed. in English)》2019,58(10):3042-3047
The incorporation of synthetic molecules as corner units in DNA structures has been of interest over the last two decades. In this work, we present a facile method for generating branched small molecule‐DNA hybrids with controllable valency, different sequences, and directionalities (5′–3′) using a “printing” process from a simple 3‐way junction structure. We also show that the DNA‐imprinted small molecule can be extended asymmetrically using polymerase chain reaction (PCR) and can be replicated chemically. This strategy provides opportunities to achieve new structural motifs in DNA nanotechnology and introduce new functionalities to DNA nanostructures. 相似文献
42.
We study several deformation functors associated to the normalization of a reduced curve singularity . The main new results are explicit formulas, in terms of classical invariants of (X, 0), for the cotangent cohomology groups T
i
, i = 0,1,2, of these functors. Thus we obtain precise statements about smoothness and dimension of the corresponding local
moduli spaces. We apply the results to obtain explicit formulas, respectively, estimates for the -codimension of a parametrized curve singularity, where denotes the Mather–Wall group of left-right equivalence. 相似文献
43.
Frederick Trinh Tan Milan Mari? James A. Nicell 《Polymer Degradation and Stability》2008,93(8):1479-1485
The aerobic biological degradation of the synthetic aliphatic-aromatic co-polyester Ecoflex™ (BASF) by 29 strains of enzyme-producing soil bacteria, fungi and yeasts was investigated at moderate environmental conditions. Previous studies had shown that these materials could be degraded but these studies were done under thermophilic conditions. In this paper, a screening procedure was developed to assess the biodegradability of the co-polyester at ambient environmental conditions and to investigate the mechanism of biodegradation. Results showed that the aliphatic-aromatic co-polyester could be degraded by a number of different microorganisms. However, after 21 days exposure to even the most promising cultures of pure microorganisms, only partial degradation of the Ecoflex™ was accomplished and only a few samples showed visible signs of degradation as loosely defined by the mechanical weakening of the films. Weight loss was not as obvious as the visual degradation and suggested broader types of microbial attack. The bacteria studied preferentially degraded the bonds between aliphatic components of the copolymer and the rate of biodegradation of oligomers was appreciably faster than that for the polymer chains. Using GC-MS techniques, degradation intermediates were identified to be the monomers of the co-polyester. Gel permeation chromatography results suggested exo-enzyme type degradation, where the microbes hydrolysed the ester bonds at the termini of the polymeric chains preferentially. 相似文献
44.
Thuy An Trinh Thai Minh Duy Le Hien Thi-Thanh Nguyen Thanh Loc Nguyen Jaeyun Kim Dai Phu Huynh Doo Sung Lee 《Macromolecular bioscience》2023,23(11):2300221
Type 2 Diabetes Mellitus (T2D) is a chronic, obesity-related, and inflammatory disorder characterize by insulin resistance, inadequate insulin secretion, hyperglycemia, and excessive glucagon secretion. Exendin-4 (EX), a clinically established antidiabetic medication that acts as a glucagon-like peptide-1 receptor agonist, is effective in lowering glucose levels and stimulating insulin secretion while significantly reducing hunger. However, the requirement for multiple daily injections due to EX's short half-life is a significant limitation in its clinical application, leading to high treatment costs and patient inconvenience. To address this issue, an injectable hydrogel system is developed that can provide sustained EX release at the injection site, reducing the need for daily injections. In this study, the electrospray technique is examine to form EX@CS nanospheres by electrostatic interaction between cationic chitosan (CS) and negatively charged EX. These nanospheres are uniformly dispersed in a pH-temperature responsive pentablock copolymer, which forms micelles and undergoes sol-to-gel transition at physiological conditions. Following injection, the hydrogel gradually degraded, exhibiting excellent biocompatibility. The EX@CS nanospheres are subsequently released, maintaining therapeutic levels for over 72 h compared to free EX solution. The findings demonstrate that the pH-temperature responsive hydrogel system containing EX@CS nanospheres can be a promising platform for the treatment of T2D. 相似文献
45.
Rameshwar Adhikari Matthias Buschnakowski Sven Henning Sylvia Goerlitz Trinh An Huy Werner Lebek Reinhold Godehardt Georg Hannes Michler Ralf Lach Kalman Geiger Konrad Knoll 《Macromolecular rapid communications》2004,25(5):653-658
Summary: The morphology and tensile deformation behaviour of a highly asymmetric styrene/butadiene star block copolymer (polystyrene (PS) content = 74%) containing random PS‐co‐PB (polybutadiene) copolymer as a rubbery phase were investigated. The existence of double yielding, similar to that observed in some semicrystalline polymers, was detected in this nanostructured amorphous polymer. The observed phenomenon may be correlated with two different micromechanical processes taking place at the initial stage of deformation.
46.
Since bioavalability of a trace metal in natural waters is affected by its chemical forms, the speciation of a trace metal becomes more and more important in environmental chemistry. Differential pulse anodic stripping voltammetry (DPASV) titration procedures are developed and applied to identify organic trace metal species of copper (Cu), lead (Pb) and zinc (Zn) in sea water and to determine their complexing capacity. 相似文献
47.
Only part of the metal present in sediments are involved in short-term geochemical processes and/or are bioavailable. Hydrous Fe- and Mn-oxides as well as organic matter partly as coatings on films on detail grains, are important substances for the interaction with dissolved metal species in aquatic systems. 相似文献
48.
Bui Dac Dung Trinh Van Giap Tibor Kovacs Tran Ngoc Toan Le Dinh Cuong Tran Khanh Minh Nguyen Huu Quyet Nguyen Van Khanh 《Journal of Radioanalytical and Nuclear Chemistry》2014,299(3):1943-1948
Mineral sands are mined in several countries to supply to the titanium and zircon producing industries. Coastal black mineral sands usually contain, besides ilmenite (FeTiO3) and rutile (TiO2), radioactive minerals such as zircon (ZrSiO4) and monazite (RePO4). Radon and thoron activity concentration originated from natural radioactive contents of the black mineral sand was monitored at the extraction and processing for black minerals in the coastal areas of Ha Tinh Province, one of the around 40 coastal mineral sand deposits in Vietnam. The survey was carried out with the Raduet chambers made by Radosys Ltd—Hungary. The obtained results for 25 investigated points show that the measured values are not high in the residential houses and in case of the sand extraction site as well. At the titanium processing plant the measured values were higher than outside the facility (Radon: 18–55 Bq/m3 with average of 34 Bq/3 and Thoron 33–118 Bq/m3 with average of 58 Bq/m3) but still comparable to the average concentration of the world published by UNSCEAR. The typical outdoor levels of radon and thoron gas are each of the order of 10 Bq/m3. Although the radon concentrations were low in the zircon and titanium processing plants, the thoron concentrations in the houses for separating rutile and zircon were very high. At zircon processing factory, the thoron concentration could reach 2,931 Bq/m3 and the estimated annual effective dose would be 21.4 mSv/a. Intervention has to be taken in order to reduce the thoron level in this factory since the level of thoron and its progenies corresponding to an annual occupational effective dose is beyond the action level of 6 mSv/a. 相似文献
49.
Duc Nghia Nguyen Trinh Tung Ngo Dae Hee Lee Min Ju Cho Dong Hoon Choi 《Journal of polymer science. Part A, Polymer chemistry》2016,54(10):1339-1347
Diketopyrrolopyrrole (DPP)‐based terpolymers—P(DPP‐TPyT) and P(DPP‐T3MTT)—bearing bithiophene donating groups and weak accepting units such as pyridine (Py) or methyl thiophene‐3‐carboxylate (3MT), in the polymer backbone, were successfully synthesized. Although the two polymers had similar physical and electrochemical properties, grazing incidence X‐ray diffraction patterns of P(DPP‐TPyT) and P(DPP‐T3MTT) showed mixed and edge‐on orientations, respectively, in thermally annealed films. Accordingly, the P(DPP‐T3MTT) showed twice the hole mobility of P(DPP‐TPyT) in a thin‐film transistor, and a blended film of P(DPP‐T3MTT) and [6,6]‐phenyl‐C71‐butyric acid methyl ester (PC71BM) showed better power conversion efficiency in a polymer solar cell. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1339‐1347 相似文献
50.
Journal of Statistical Physics - We establish the strong law of large numbers for Betti numbers of random ?ech complexes built on $${\mathbb {R}}^N$$ -valued binomial point processes and... 相似文献