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991.
Yu-Chuan Liang Can-Yong Jhu Sheng-Hung Wu Sun-Ju Shen Chi-Min Shu 《Journal of Thermal Analysis and Calorimetry》2011,106(1):173-177
Methyl ethyl ketone peroxide (MEKPO) is generally applied to manufacturing in the polymerization processes. Due to thermal
instability and high exothermic behaviors of MEKPO, if any operation is undertaken recklessly or some environmental effect
is produced suddenly during the processes, fires and explosions may inevitably occur. In this study, thermal analysis was
evaluated for MEKPO by differential scanning calorimetry (DSC) test. Vent sizing package 2 (VSP2) was used to analyze the
thermal hazard of MEKPO under various stirring rates in a batch reactor. Thermokinetic and safety parameters, including exothermic
onset temperature (T
0), maximum temperature (T
max), maximum pressure (P
max), self-heating rate (dT dt
−1), pressure rise rate (dP dt
−1), and so on, were discovered to identify the safe handling situation. The stirring rates of reactor were confirmed to affect
runaway and thermal hazard characteristics in the batch reactor. If the stirring rate was out of control, it could soon cause
a thermal hazard in the reactor. 相似文献
992.
A biodegradable tumor targeting nano-probe based on poly(ε-caprolactone)-b-poly(ethylene glycol)block copolymer(PCL-b-PEG)micelle functionalized with a magnetic resonance imaging(MRI)contrast agent diethylenetriaminepentaacetic acid-gadolinium(DTPA-Gd3+)on the shell and a near-infrared(NIR)dye in the core for magnetic resonance and optical dual-modality imaging was prepared.The longitudinal relaxivity(r1)of the PCL-b-PEG-DTPA -Gd3+micelle was 13.4(mmol/L)-1s-1,three folds of that of DTPA-Gd3+,and higher than that of many polymeric contrast agents with similar structures.The in vivo optical imaging of a nude mouse bearing xenografted breast tumor showed that the dual-modality micelle preferentially accumulated in the tumor via the folic acid-mediated active targeting and the passive accumulation by the enhanced permeability and retention(EPR)effect.The results indicated that the dualmodality micelle is a promising nano-probe for cancer detection and diagnosis. 相似文献
993.
Two alternating narrow band gap (NBG) copolymers derived from 5,11-di(N-9-heptadecanyl)-indolo[3,2-b]carbazole (ICZ) and 4,7-di(thien-2-yl)-2′,1′,3′-benzoselenadiazole (DSeBT) or 4,7-di(thieno[3,2-b]thien-2-yl)-2′,1′,3′-benzoselenadiazole (DTSeBT), were synthesized and named PICZ-DSeBT and PICZ-DTSeBT, respectively. The
PICZ-DSeBT shows good solubility in common organic solvent, and the PICZ-DTSeBT is soluble in hot o-dichlorobenzene (ODCB) and not good soluble in chloroform, toluene etc. The chemical structure, molecular weight and fundamental
physical properties of the copolymers were characterized by 1H NMR, gel permeation chromatography (GPC), cyclic voltammetry (CV), thermal gravimetric analysis (TGA) and differential scanning
calorimetry (DSC) etc. Potential application of the copolymers to be employed as electron donor material and PC61BM ([6,6]-phenyl-C61 butyric acid methyl ester) for photovoltaic solar cells (PSCs), were investigated. PSCs based on the blends of PICZ-DSeBT/PC61BM (w: w; 1: 2) or PICZ-DTSeBT/PC61BM (w: w; 1: 2) with devices configuration as ITO/PEDOT: PSS/blend/Al, show the power conversion efficiencies (PCEs) of 1.06%
and 1.52%, with the open circuit voltage (V
oc) of 0.75 V and 0.70 V, short circuit current densities (J
sc) of 3.45 mA/cm2 and 5.30 mA/cm2 under an AM1.5 simulator (100 mW/cm2) and the photocurrent response on-set wavelength extending up to 760 nm and 800 nm, respectively. It indicates that the NBG
copolymers are viable electron donor materials for PSCs. 相似文献
994.
Xiao Zhou Yali Lu Wenjing Wang Babak Borhan Gavin E. Reid 《Journal of the American Society for Mass Spectrometry》2010,21(8):1339-1351
Protein surface accessible residues play an important role in protein folding, protein-protein interactions and protein-ligand
binding. However, a common problem associated with the use of selective chemical labeling methods for mapping protein solvent
accessible residues is that when a complicated peptide mixture resulting from a large protein or protein complex is analyzed,
the modified peptides may be difficult to identify and characterize amongst the largely unmodified peptide population (i.e.,
the ‘needle in a haystack’ problem). To address this challenge, we describe here the development of a strategy involving the
synthesis and application of a novel ‘fixed charge’ sulfonium ion containing lysine-specific protein modification reagent,
S,S′-dimethylthiobutanoylhydroxysuccinimide ester (DMBNHS), coupled with capillary HPLC-ESI-MS, automated CID-MS/MS, and data-dependant
neutral loss mode MS3 in an ion trap mass spectrometer, to map the surface accessible lysine residues in a small model protein, cellular retinoic
acid binding protein II (CRABP II). After reaction with different reagent:protein ratios and digestion with Glu-C, modified
peptides are selectively identified and the number of modifications within each peptide are determined by CID-MS/MS, via the
exclusive neutral loss(es) of dimethylsulfide, independently of the amino acid composition and precursor ion charge state
(i.e., proton mobility) of the peptide. The observation of these characteristic neutral losses are then used to automatically
‘trigger’ the acquisition of an MS3 spectrum to allow the peptide sequence and the site(s) of modification to be characterized. Using this approach, the experimentally
determined relative solvent accessibilities of the lysine residues were found to show good agreement with the known solution
structure of CRABP II. 相似文献
995.
Indigo is one of the oldest dyes manufactured chemically and is mostly used in textile, food, and pharmaceutical industries.
However, owing to the environmental hazards posed by the chemical production, the present scenario in the field stipulates
a biosynthesis alternative for indigo production. The present study describes an indigenously isolated naphthalene-degrading
strain Pseudomonas sp. HOB1 producing a blue pigment when indole was added in the growth medium. This blue pigment was analyzed by high-pressure
thin-layer chromatography and other spectroscopic techniques which revealed it to be the indigo dye. Pseudomonas sp. HOB1 showed ability to produce 246 mg indigo liter−1 of the medium. The K
m for the enzyme naphthalene dioxygenase which is involved in indigo formation is 0.3 mM, and V
max was as high as 50 nmol min−1 mg dry biomass−1. The bacterial indigo dye was further successfully applied for dyeing cotton fabrics. The high indigo productivity of Pseudomonas sp. HOB1 using naphthalene as growth substrate and its applicability on cotton fabrics, therefore, stems the probability
of using this culture for commercial indigo production. 相似文献
996.
Sanjay S. Latthe Hiroaki Imai V. Ganesan Charles Kappenstein A. Venkateswara Rao 《Journal of Sol-Gel Science and Technology》2010,53(2):208-215
Optically transparent silica films were prepared at room temperature (~27°C) by keeping the molar ratio of TEOS:MeOH:H2O (0.001 M NH4F) constant at 1:19.29:6.20, respectively. A surface chemical modification of the films was done with alkylchlorosilanes at
different concentrations from 0 to 1 vol. % and aging times varied from half to 2 h. The DMCS and TMCS surface modified silica
films showed the static water contact angle of 146° and 162°, respectively. When the DMCS and TMCS modified films were cured
at temperatures higher than 240 and 275°C, respectively, the films became superhydrophilic. Further, the humidity study was
carried out at a relative humidity of 90% at 30°C temperature over 60 days. We characterized the water repellent silica films
by Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy, % of optical transmission,
humidity tests and contact angle measurements. 相似文献
997.
Nives Škrlj Vladka Čurin Šerbec Marko Dolinar 《Applied biochemistry and biotechnology》2010,160(6):1808-1821
Prion diseases are incurable neurodegenerative diseases that affect both humans and animals. The infectious agent is a pathogenic
form of the prion protein that accumulates in brain as amyloids. Currently, there is neither cure nor reliable preclinical
diagnostics on the market available. The growing number of reports shows that passive immunisation is one of the most promising
strategies for prion disease therapy, where antibodies against prions may prevent and even cure the infection. Since antibodies
are large molecules and, thus, might not be suitable for the therapy, different antibody fragments are a good alternative.
Therefore, we have designed and prepared single-chain antibody fragments (scFvs) derived from the PrPSc-specific murine monoclonal antibody V5B2. Using a new expression vector pMD204, we produced scFvs in two opposing chain orientations
in the periplasm of Escherichia coli. Both recombinant antibody fragments retained the specificity of the parent antibody and one of these exhibited binding properties
comparable to the corresponding murine Fab fragments with the affinity in nM range. Our monovalent antibody fragments are
of special interest in view of possible therapeutic reagents for prion diseases as well as for development of a new generation
of diagnostics. 相似文献
998.
Francisco López-Suevos Christian Eyholzer Nico Bordeanu Klaus Richter 《Cellulose (London, England)》2010,17(2):387-398
Suspensions of commercial refined beech pulp (RBP) were further processed through mechanical disintegration (MD-RBP), chemical
modification (CM-RBP) and through chemical modification followed by mechanical disintegration (CM-MD-RBP). Nanocomposites
were prepared by compounding a poly(vinyl acetate) (PVAc) latex adhesive with increasing contents of the different types of
nanofibrils, and the resulting nanocomposites were analyzed by dynamic mechanical analysis (DMA). Also, the suitability of
using the CM-RBP fibrils to formulate PVAc adhesives for wood bonded assemblies with improved heat resistance was studied.
The presence of cellulose nanofibrils had a strong influence on the viscoelastic properties of PVAc latex films. For all nanocomposites,
increasing amounts of cellulose nanofibrils (treated or untreated) led to increasing reinforcing effects in the glassy state,
but especially in the PVAc and PVOH glass transitions. This reinforcement primarily resulted from interactions between the
cellulose fibrils network and the hydrophilic PVOH matrix that led to the complete disappearance of the PVOH glass transition
(tan δ peak) for some fibril types and contents. At any given concentration in the PVOH transition, the CM-MD-RBP nanofibrils
provided the highest reinforcement, followed by the MD-RBP, CM-RBP and the untreated RBP. Finally, the use of the CM-RBP fibrils
to prepare PVAc reinforced adhesives for wood bonding was promising since, even though they generally performed worse in dry
and wet conditions, the boards showed superior heat resistance (EN 14257) and passed the test for durability class D1. 相似文献
999.
Inhibition effect of imidazole derivative 1,7′-dimethyl-2′-propyl-1H,3′H-2,5′-bibenzo[d]imidazole (DPBI) against mild steel corrosion in 1 M HCl solutions was evaluated using the conventional mass loss method,
potentiodynamic polarization, linear polarization, and electrochemical impedance spectroscopy. The mass loss results showed
that DPBI is an excellent corrosion inhibitor; electrochemical polarizations data revealed the mixed mode of inhibition; and
the results of electrochemical impedance spectroscopy showed that the change in the impedance parameters, charge transfer
resistance, and double layer capacitance with the change in the concentration of the inhibitor is due to the adsorption of
the molecule leading to the formation of a protective layer on the surface of mild steel. The inhibition action of this compound
was assumed to occur via adsorption on the steel surface through the active centers of the molecule. 相似文献
1000.
Jia-Zheng Lu Yi-fan Du Bin Wu Jin-Wang Huang Jing Jiang 《Transition Metal Chemistry》2010,35(4):451-456
A fluorescein–porphyrin hybrid (Fl-PTPP) has been synthesized and characterized by UV/Vis, IR, 1H NMR, ES-MS and elemental analysis. The supramolecular self-assembly of Fl-PTPP with the copper(II) complex of 5-(p-amino-phenyl)-10,15,20-triphenylporphyrin, (CuAPTPP), by hydoxyl-amino type hydrogen bonding was studied using vapor pressure
osmometry (VPO) measurements, ES-MS, UV/Vis, 1H NMR and fluorescence spectroscopic titration. The data indicate formation of a (Fl-PTPP)–CuAPTPP supramolecular complex.
Fluorescence strengthening character was observed in a spectroscopic titration experiment for the Fl-PTPP/CuAPTPP system.
The association constant of the supramolecular complex was calculated from the fluorescence titration data, and found to be
less than that of a carboxyl–carboxyl type hydrogen-bonding system. 相似文献