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排序方式: 共有409条查询结果,搜索用时 15 毫秒
51.
AK Purohit MD Balish JJ Leichty A Roe LM Ward MO Mitchell SC Hsia 《Bioorganic & medicinal chemistry letters》2012,22(16):5308-5312
N-(4-chlorobenzyl)triflupromazinium chloride, a known antitubercular agent, has been found to also be active against HSV-1. A preliminary structure-activity relation has been explored to determine which groups are crucial to viral inhibition. Antiviral assessments such as GFP reduction, plaque reduction, treatment timing and wash-out studies have also been probed to determine a mode of action for QPD-1. Based on this preliminary data, it appears that QPD-1 is a reversible inhibitor, suspected to inhibit early stages of viral replication of HSV-1 at 50μM, equipotent to acyclovir. 相似文献
52.
Gnesa E Hsia Y Yarger JL Weber W Lin-Cereghino J Lin-Cereghino G Tang S Agari K Vierra C 《Biomacromolecules》2012,13(2):304-312
Spider silk is renowned for its extraordinary mechanical properties, having a balance of high tensile strength and extensibility. To date, the majority of studies have focused on the production of dragline silks from synthetic spider silk gene products. Here we report the first mechanical analysis of synthetic egg case silk fibers spun from the Latrodectus hesperus tubuliform silk proteins, TuSp1 and ECP-2. We provide evidence that recombinant ECP-2 proteins can be spun into fibers that display mechanical properties similar to other synthetic spider silks. We also demonstrate that silks spun from recombinant thioredoxin-TuSp1 fusion proteins that contain the conserved C-terminal domain exhibit increased extensibility and toughness when compared to the identical fibers spun from fusion proteins lacking the C-terminus. Mechanical analyses reveal that the properties of synthetic tubuliform silks can be modulated by altering the postspin draw ratios of the fibers. Fibers subject to increased draw ratios showed elevated tensile strength and decreased extensibility but maintained constant toughness. Wide-angle X-ray diffraction studies indicate that postdrawn fibers containing the C-terminal domain of TuSp1 have more amorphous content when compared to fibers lacking the C-terminus. Taken together, these studies demonstrate that recombinant tubuliform spidroins that contain the conserved C-terminal domain with embedded protein tags can be effectively spun into fibers, resulting in similar tensile strength but increased extensibility relative to nontagged recombinant dragline silk proteins spun from equivalently sized proteins. 相似文献
53.
Dubey A Boukouvala F Keyvan G Hsia R Saranteas K Brone D Misra T Ierapetritou MG Muzzio FJ 《AAPS PharmSciTech》2012,13(1):231-246
A combination of analytical and statistical methods is used to improve a tablet coating process guided by quality by design
(QbD) principles. A solid dosage form product was found to intermittently exhibit bad taste. A suspected cause was the variability
in coating thickness which could lead to the subject tasting the active ingredient in some tablets. A number of samples were
analyzed using a laser-induced breakdown spectroscopy (LIBS)-based analytical method, and it was found that the main variability
component was the tablet-to-tablet variability within a lot. Hence, it was inferred that the coating process (performed in
a perforated rotating pan) required optimization. A set of designed experiments along with response surface modeling and kriging
method were used to arrive at an optimal set of operating conditions. Effects of the amount of coating imparted, spray rate,
pan rotation speed, and spray temperature were characterized. The results were quantified in terms of the relative standard
deviation of tablet-averaged LIBS score and a coating variability index which was the ratio of the standard deviation of the
tablet-averaged LIBS score and the weight gain of the tablets. The data-driven models developed based on the designed experiments
predicted that the minimum value of this index would be obtained for a 6% weight gain for a pan operating at the highest speed
at the maximum fill level while using the lowest spraying rate and temperature from the chosen parametric space. This systematic
application of the QbD-based method resulted in an enhanced process understanding and reducing the coating variability by
more than half. 相似文献
54.
Efforts to engineer synthetic gene networks that spontaneously produce patterning in multicellular ensembles have focused on Turing's original model and the "activator-inhibitor" models of Meinhardt and Gierer. Systems based on this model are notoriously difficult to engineer. We present the first demonstration that Turing pattern formation can arise in a new family of oscillator-driven gene network topologies, specifically when a second feedback loop is introduced which quenches oscillations and incorporates a diffusible molecule. We provide an analysis of the system that predicts the range of kinetic parameters over which patterning should emerge and demonstrate the system's viability using stochastic simulations of a field of cells using realistic parameters. The primary goal of this paper is to provide a circuit architecture which can be implemented with relative ease by practitioners and which could serve as a model system for pattern generation in synthetic multicellular systems. Given the wide range of oscillatory circuits in natural systems, our system supports the tantalizing possibility that Turing pattern formation in natural multicellular systems can arise from oscillator-driven mechanisms. 相似文献
55.
56.
Hsia SM Kuo YH Chiang W Wang PS 《American journal of physiology. Endocrinology and metabolism》2008,295(3):E719-E726
Dysmenorrhea is directly related to elevated PGF(2alpha) levels. It is treated with nonsteroid antiinflammatory drugs (NSAIDs) in Western medicine. Since NSAIDs produce many side effects, Chinese medicinal therapy is considered as a feasible alternative medicine. Adlay (Coix lachryma-jobi L. var. ma-yuen Stapf.) has been used as a traditional Chinese medicine for treating dysmenorrhea. However, the relationship between smooth muscle contraction and adlay extracts remains veiled. Therefore, we investigated this relationship in the rat uterus by measuring uterine contraction activity and recording the intrauterine pressure. We studied the in vivo and in vitro effects of the methanolic extracts of adlay hull (AHM) on uterine smooth muscle contraction. The extracts were fractionated using four different solvents: water, 1-butanol, ethyl acetate, and n-hexane; the four respective fractions were AHM-Wa, AHM-Bu, AHM-EA, and AHM-Hex. AHM-EA and its subfractions (175 microg/ml) inhibited uterine contractions induced by PGF(2alpha), the Ca(2+) channel activator Bay K 8644, and high K(+) in a concentration-dependent manner in vitro. AHM-EA also inhibited PGF(2alpha)-induced uterine contractions in vivo; furthermore, 375 microg/ml of AHM-EA inhibited the Ca(2+)-dependent uterine contractions. Thus 375 microg/ml of AHM-EA consistently suppressed the increases in intracellular Ca(2+) concentrations induced by PGF(2alpha) and high K(+). We also demonstrated that naringenin and quercetin are the major pure chemical components of AHM-EA that inhibit PGF(2alpha)-induced uterine contractions. Thus AHM-EA probably inhibited uterine contraction by blocking external Ca(2+) influx, leading to a decrease in intracellular Ca(2+) concentration. Thus adlay hull may be considered as a feasible alternative therapeutic agent for dysmenorrhea. 相似文献
57.
58.
D Merrill Dane Xiao Yan Rahul M Tamhane Robert L Johnson Aaron S Estrera Deborah C Hogg Richard T Hogg Connie C W Hsia 《Journal of applied physiology》2004,96(3):1090-1096
To determine whether all-trans retinoic acid (RA) treatment enhances lung function during compensatory lung growth in fully mature animals, adult male dogs (n = 4) received 2 mg x kg(-1) x day(-1) po RA 4 days/wk beginning the day after right pneumonectomy (R-PNX, 55-58% resection). Litter-matched male R-PNX controls (n = 4) received placebo. After 3 mo, transpulmonary pressure (TPP)-lung volume relationship, diffusing capacities for carbon monoxide and nitric oxide, cardiac output, and septal volume (V(tiss-RB)) were measured under anesthesia by a rebreathing technique at two lung volumes. Lung air and tissue volumes (V(air-CT) and V(tiss-CT)) were also measured from high-resolution computerized tomographic (CT) scans at a constant TPP. In RA-treated dogs compared with controls, TPP-lung volume relationships were similar. Diffusing capacities for carbon monoxide and nitric oxide were significantly impaired at a lower lung volume but similar at a high lung volume. Whereas V(tiss-RB) was significantly lower at both lung volumes in RA-treated animals, V(air-CT) and V(tiss-CT) were not different between groups; results suggest uneven distribution of ventilation consistent with distortion of alveolar geometry and/or altered small airway function induced by RA. We conclude that RA does not improve resting pulmonary function during the early months after R-PNX despite histological evidence of its action in enhancing alveolar cellular growth in the remaining lung. 相似文献
59.
O. D. Anderson C. C. Hsia A. E. Adalsteins E. J.-L. Lew D. D. Kasarda 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(2-3):307-315
During the initial phases of a wheat endosperm Expressed-Sequence-Tag (EST) project, several clones were determined to be
related to wheat gliadin sequences, but not similar enough to be classified into any of the traditional gliadin families [α-,
γ-, and ω-gliadins, low-molecular-weight (LMW) glutenins]. Complete sequences of these cDNA clones revealed four new classes
of gliadin-related endosperm proteins, but lacking a prominent repeat domain which until now has been characteristic of the
gliadins. Two of these classes are related to different minimally described groups of Triticeae endosperm proteins. One class
of proteins, which has N-terminal amino-acid sequences matching members of a reported 25-kDa globulin family from wheat, is
shown by amino-acid sequencing to match to a family of 25-kDa endosperm proteins, is encoded by a multigene family, and is
most similar to the LMW-glutenins. A second new class shows N-terminal homologies to LMW secalins from rye, and has an amino-acid
composition similar to wheat and barley LMW proteins with extraction properties similar to prolamins. The third class is most
similar to α-gliadins, and the fourth class has no close association to previously described wheat endosperm proteins.
Received: 20 October 2000 / Accepted: 20 November 2000 相似文献
60.
The distribution of fatty acids and diethylstilbestrol between serum albumin and alpha-fetoprotein was measured in vitro by a new method based on the separation of the two proteins by virtue of the binding specificity of concanavalin A for the carbohydrate moiety of alpha-fetoprotein. Human and bovine proteins were investigated. It was found that palmitate and oleate were distributed almost equally between albumin and alpha-fetoprotein, while docosahexaenoate and diethylstilbestrol bound preferentially to alpha-fetoprotein even at an albumin: alpha-fetoprotein ratio of 10:1. The results confirm the binding specificity of alpha-fetoprotein for polyunsaturated fatty acids and also show that alpha-fetoprotein binds diethylstilbestrol much more strongly than albumin does. This suggests that alpha-fetoprotein may play a role in the fetal uptake of diethylstilbestrol. 相似文献