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When producing hydrolyzed proteins, it is important to determine the degree of hydrolysis (DH). The trinitro-benzene-sulfonic acid (TNBS) method is well established with regard to enzymatic hydrolysis. However, this method is laborious, cannot be used to follow a hydrolysis reaction continuously, and includes hazardous and unstable chemicals. This paper describes a method based on the reaction of primary amino groups with o-phthaldialdehyde (OPA). The conclusion is that the OPA method of analyzing the DH of protein hydrolyses is more accurate, is easier and faster to carry out, has a broader application range, and is environmentally safer than the TNBS method. [ABSTRACT FROM AUTHOR]

The subchronic toxicity of 1,3,5-trinitrobenzene (TNB) in male and female Fischer 344 rats was evaluated by feeding a powdered certified laboratory diet containing 0, 66.7, 400 and 800 mg TNB/kg diet for 90 days. The calculated average TNB intake was 4.29, 24.70, and 49.28 mg/kg body weight (BW)/day for females and 3.91, 22.73, and 44.16 mg/kg BW/day for males. Food intake in the 400 and 800 mg/kg diet dose groups of both sexes was decreased throughout the study and resulted in a significant decrease in absolute body weights. A significant decrease in relative testicular weights and a significant increase in the relative liver weight were observed in male rats receiving 400 or 800 mg TNB/kg diet. A significant increase in the relative spleen weights of both sexes receiving 400 or 800 mg TNB diet was noted. The relative liver weight was also increased only in female rats maintained on the 800 mg TNB diet. Histopathological examinations revealed that the susceptible organs for TNB toxicity were kidney (hyaline droplets) in all male dose groups and testes (seminiferous tubular degeneration)in rats receiving 400 and 800 mg TNB diet groups. The spleen was alsoaffected (extramedullary hematopoiesis)in both sexes in the400 and 800 mg dose groups. Hematological studies at both 45 (data not given) and 90 days in the 400 and 800 mg dose groups indicated decreased values for red blood cell counts and hemoglobin content, while reticulocytes and methemoglobin levels wereincreased. Clinical chemistry parameters wereunaffected. Based on kidney toxicity and hematological effects,a Low Observed AdverseEffect Level (LOAEL) of 3.91 mg/kg BW/day was suggested for subchronic toxicity studies on TNB. [ABSTRACT FROM AUTHOR]

Intestinal fibrosis associated with Crohn's disease (CD), which a common and serious complication of inflammatory bowel diseases. In this context, heat shock proteins (HSPs) might serve as an alternative treatment because these antigens play important roles in the regulation of effector T cells. We thus evaluated the anti-inflammatory and antifibrotic capacities of an invasive and Hsp65-producing strain—Lactococcus lactis NCDO2118 FnBPA+ (pXYCYT:Hsp65)—in chronic intestinal inflammation to assess its potential as an alternative therapeutic strategy against fibrotic CD. Experimental colitis was induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) in BALB/c mice, and the mice were treated orally with L. lactis NCDO2118 FnBPA+ (pXYCYT:Hsp65) via intragastric gavage. The oral administration of this strain significantly attenuated the severity of inflammation and intestinal fibrosis in mice (p < 0.05). These results are mainly justified by reductions in the levels of the pro-fibrotic cytokines IL-13 and TGF-β and increases in the concentration of the regulatory cytokine IL-10. The L. lactis NCDO2118 FnBPA+ (pXYCYT:Hsp65) strain contributed to reductions in the severity of inflammatory damage in chronic experimental CD, and these findings confirm the effectiveness of this new antifibrotic strategy based on the delivery of therapeutic proteins to inside cells of the host intestinal mucosa. [ABSTRACT FROM AUTHOR]

Bond stretching and three-center angle bending potentials have been developed to extend an existing rigid-bond 1,3,5-triamino-2,4,6-trinitrobenzene molecular dynamics force field [D. Bedrov, O. Borodin, G. D. Smith, T. D. Sewell, D. M. Dattelbaum, and L. L. Stevens, J. Chem. Phys. 131, 224703 (2009)] for simulations requiring fully flexible molecules. The potentials were fit to experimental vibrational spectra and electronic structure predictions of vibrational normal modes using a combination of zero kelvin eigenmode analysis for the isolated molecule and power spectra for the isolated molecule and crystal. A reverse non-equilibrium molecular dynamics method [F. Müller-Plathe, J. Chem. Phys. 106, 6082 (1997)] was used to obtain the room temperature, atmospheric pressure thermal conductivity along three directions in a well-defined, non-orthogonal basis. The thermal conductivity was found to be significantly anisotropic with values 1.13 ± 0.07, 1.07 ± 0.07, and 0.65 ± 0.03 W m-1 K-1 for directions nominally parallel to the a, b, and c lattice vectors, respectively. [ABSTRACT FROM AUTHOR]

In order to improve the safety of 2,4,6,8,10,12‐hexanitro‐2,4,6,8,10,12‐hexaazaisowurtzitane (CL‐20) while preserving its high energy yield, a nanocomposite containing CL‐20 and 1,3,5‐triamino‐2,4,6‐trinitrobenzene (TATB) with a particular structure is prepared using an facile and fast antisolvent crystallization method. Using this approach, which takes advantage of strong antisolvent and temperature effects, a lamellar arrangement structure is created consisting of nanosheets containing CL‐20 and TATB, and further coated with dendritic nanometer‐scale TATB. XRD and Raman spectra indicate that CL‐20 in the resulting nanocomposite takes the form of α polymorph owing to the presence of ultrapure water. The HPLC results show that the TATB content of the nanocomposite is 20.2 wt%. When the surface coating of TATB is removed, 8 wt% TATB remains between the internal nanosheets. Due to the multiple desensitization effects of this structure, the nanocomposite has much lower sensitivity, roughly comparable to that of the insensitive explosive LLM‐105. Thermal analysis by thermogravimetry (TG) and differential scanning calorimeter indicates that the thermal decomposition activity of the nanocomposite is higher than those of raw materials, and in addition, its thermal stability is greater. Using a facile and fast antisolvent crystallization method to prepare nanocomposite a lamellar arrangement structure is created consisting of nanosheets containing CL‐20 and TATB, and further coated with dendritic nanometer‐scale TATB. The nanocomposite has a low impact sensitivity. The formation mechanism is elucidated based on the structure analysis. [ABSTRACT FROM AUTHOR]

In order to study the fracture behavior and structure evolution of 1,3,5-Triamino-2,4,6-Trinitrobenzene (TATB)-based polymer bonded explosive in thermal-mechanical loading, in-situ studies were performed on X-ray computed tomography system using quasi-static Brazilian test. The experiment temperature was set from −20 °C to 70 °C. Three-dimensional morphology of cracks at different temperatures was obtained through digital image process. The various fracture modes were compared by scanning electron microscopy. Fracture degree and complexity were defined to quantitatively characterize the different types of fractures. Fractal dimension was used to characterize the roughness of the crack surface. The displacement field of particles in polymer bonded explosive (PBX) was used to analyze the interior structure evolution during the process of thermal-mechanical loading. It was found that the brittleness of PBX reduced, the fracture got more tortuous, and the crack surface got smoother as the temperature rose. At lower temperatures, especially lower than glass transition temperature of binders, there were slipping and shear among particles, and particles tended to displace and disperse; while at higher temperatures, especially above the glass transition temperature of binders, there was reorganization of particles and particles tended to merge, disperse, and reduce sizes, rather than displacing. [ABSTRACT FROM AUTHOR]

Using dispersion corrected density functional theory, we systematically examined the pressure effect on crystal structure, cell volume, and band gap of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) to understand its extraordinary chemical stability. Analysis of the Mulliken population and the electron density of states implied a possible charge transfer in TATB with increasing pressure. Raman and infrared spectra of TATB under hydrostatic pressure up to 30 GPa were simulated. The observed strong coupling between NH2 groups and NO2 groups with increasing pressure, which is considered to have a tendency of energy transfer with these vibrational modes, was analyzed. The pressure-induced frequency shift of selected vibrational modes indicated minor changes of molecular conformation mainly by the rotation of NH2 groups. Compression behavior and spectroscopic property studies are expected to shed light on the physical and chemical properties of TATB on an atomistic scale. [ABSTRACT FROM AUTHOR]

Background: Mesenchymal stem cells have potential applications in inflammatory bowel disease due to their immunomodulatory properties. Our aim was to evaluate the feasibility, safety and efficacy of endoscopic administration of adipose-derived mesenchymal stem cells (ASCs) in a colitis model in rats. Methods: Colitis was induced in rats by rectal trinitrobenzenesulfonic acid (TNBS). After 24 h ASCs (107 cells) or saline vehicle were endoscopically injected into the distal colon. Rats were followed for 11 days. Daily weight, endoscopic score at days 1 and 11, macroscopic appearance at necropsy, colon length and mRNA expression of Foxp3 and IL-10 in mesenteric lymph nodes (MLN) were analyzed. Results: Endoscopic injection was successful in all the animals. No significant adverse events or mortality due to the procedure occurred. Weight evolution was significantly better in the ASC group, recovering initial weight by day 11 (− 0.8% ± 10.1%, mean ± SD), whereas the vehicle group remained in weight loss (− 6.7% ± 9.2%, p = 0.024). The endoscopic score improved in the ASC group by 47.1% ± 5.3% vs. 21.8% ± 6.6% in the vehicle group (p < 0.01). Stenosis was less frequent in the ASC group (4.8% vs. 41.2%, p < 0.01). Colon length significantly recovered in the ASC group versus the vehicle group (222.6 ± 17.3 mm vs. 193.6 ± 17.9 mm, p < 0.001). The endoscopic score significantly correlated with weight change, macroscopic necropsy score and colon length. Foxp3 and IL-10 mRNA levels in MLN recovered with ASC treatment. Conclusions: ASC submucosal endoscopic injection is feasible, safe and ameliorates TNBS-induced colitis in rats, especially stenosis. [ABSTRACT FROM AUTHOR]

Perovskite bismuth ferrite-BFO (1 1 1) membranes, as potential-sensitive electrochemical sensors, are investigated for the detection of high-energy-density materials by molecular dynamics (MD) and density functional theory (DFT) calculations. For the detection mechanism of the sensitive 1, 1-diamino-2, 2-dinitroethylene (FOX-7) gases, both a cation bridge and electrostatic models can be used to explain the STM signatures as 0.02–0.04 V (single) and 0.03~0.05 V (coverage) over a wide range (0–0.1 V) of bias voltages. For insensitive 1, 3, 5-triamino-2, 4, 6-trinitrobenzene (TATB) gases interacting with the surface of a BFO (1 1 1) membrane, the charge signature can be as high as 0.08 V (coverage: 0.06 V). Analysis indicates a significant difference from the detection mechanism observed for FOX-7 gases; that is, the molecularly intact bidentate bridge configuration with only – bonds binds to both Fe and Bi atoms. These differences are attributed so that the surface O2− of BFO will capture a part of the surface electron of the –NO2 group, creating a 2p-hole defect (h+) which annihilates a spinning upward (↑) Fe3+, forming a spinning downward (↓) Fe2+. The –NO2 electron decreases 0.35 e (single FOX-7; coverage FOX-7: 0.24 e) and 0.56 e (single TATB; coverage TATB: 0.06 e). Such a system could open up new ideas in the design and application of BFO-based sensors. [ABSTRACT FROM AUTHOR]

The hazardous wastes generated in the manufacture of high-explosive 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) from starting material 1,3,5-trichlorobenzene are described. The process generates three kinds of effluents: water-based nitration effluent (WNE), toluene-based amination effluent (TAE), and water-based amination effluent (WAE). These three effluents are analyzed as per the country's pollution control norms. Both WNE and WAE need treatment before discharge to the environment. These treatment methodologies are discussed. The solvent recovery from TAE was found highly feasible. However, some solid organic explosive waste ( TATB produced) is generated from the residue of TAE after solvent recovery. The composition of this solid waste is analyzed by gas chromatography and its potential explosiveness is characterized by a sensitivity test. The disposal methodology of the solid wastes generated from WNE, TAE, and WAE are also discussed. [ABSTRACT FROM AUTHOR]