Thermal Behaviors and Interaction Mechanism of Ammonium Dinitramide with Nitrocellulose.

The initial interaction mechanism is very important for the design and safety of nano-scale composite energetic materials composed of ammonium dinitramide (ADN) and nitrocellulose (NC). The thermal behaviors of ADN, NC and an NC/ADN mixture under different conditions were studied by using differential scanning calorimetry (DSC) with sealed crucibles, an accelerating rate calorimeter (ARC), a self-developed gas pressure measurement instrument and a DSC-thermogravimetry (TG)-quadrupole mass spectroscopy (MS)-Fourier transform infrared spectroscopy (FTIR) combined technique. The results show that the exothermic peak temperature of the NC/ADN mixture shifted forward greatly in both open and closed circumstances compared to those of NC or ADN. After 585.5 min under quasi-adiabatic conditions, the NC/ADN mixture stepped into the self-heating stage at 106.4 °C, which was much less than the initial temperatures of NC or ADN. The significant reduction in net pressure increment of NC, ADN and the NC/ADN mixture under vacuum indicates that ADN initiated the interaction of NC with ADN. Compared to gas products of NC or ADN, two new kinds of oxidative gases O2 and HNO2 appeared for the NC/ADN mixture, while NH3 and aldehyde disappeared. The mixing of NC with ADN did not change the initial decomposition pathway of either, but NC made ADN more inclined to decompose into N2O, which resulted in the formation of oxidative gases O2 and HNO2. The thermal decomposition of ADN dominated the initial thermal decomposition stage of the NC/ADN mixture, followed by the oxidation of NC and the cation of ADN.

[Effects of oligomeric grape seed proanthocyanidins on isoproterenol-induced cardiac remodeling in rats].

The purpose of this study is to evaluate the effect of oligomeric grape seed proanthocyanidins (GSP) on isoproterenol (ISO)-induced cardiac remodeling in rats. ISO was given subcutaneously (5 mg x kg(-1), sc, 7 days) to induce cardiac remodeling in rats. Therapeutic groups were given GSP (50, 100, and 150 mg x kg(-1)) after ISO treatment. After 2 weeks intervention, heart rate (HR), left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), rate of rise of left ventricular pressure (+/- dp/dt(max)) were examined. The myocardial hypertrophy index was expressed as heart weight/body weight (HW/BW) and left ventricle weight/body weight (LVW/BW), the histological changes were investigated by HE and Van Gieson stain. SOD activity and MDA content in serum, contents of hydroxyproline (Hyp) in the left ventricular tissue were assayed by xanthinoxidase method, thiobarbituric acid (TBA) method and alkaline hydrolysis method, respectively. After the onset of ISO-treatment, GSP therapy potently improved cardiac function, inhibited myocardial hypertrophy, improved cardiac pathology change, decreased the myocardial cross-section area (CSA), collagen volume fraction (CVF) and perivascular circumferential collagen area (PVCA), reduced the content of Hyp in the left ventricular tissue, inhibited the decrease of SOD activity and increase of MDA content in serum. GSP possess protective effect against ISO induced cardiac remodeling in rats, this may be related to reducing the oxidative stress and improving antioxidant capacity.

Clinical Characteristics of Transarterial Chemoembolization in Treatment of Primary Hepatocellular Carcinoma Complicated With Respiratory Distress Syndrome.

OBJECTIVE: The present study aims to analyze the clinical characteristics and etiology of transarterial chemoembolization (TACE) in the treatment of hepatocellular carcinoma (HCC) complicated with acute respiratory distress syndrome (ARDS), in order to improve the early diagnosis rate and cure rate. METHODS: A total of 816 patients with primary HCC received 2,200 TACE treatments from January 2014 to May 2018. Among these patients, 6 patients developed ARDS after TACE. The clinical data, lesion characteristics, laboratory tests, treatment process and prognosis of 6 patients were retrospectively analyzed. RESULTS: The longest lesion diameter ranged within 5.0-10.2 cm (mean: 6.6 cm) in the 6 patients with primary HCC. Among these patients, 4 patients had lesions mainly located in the left lateral lobe of the liver, while 5 patients had no hepatic arteriovenous fistula detected before TACE. Nedaplatin, epirubicin and iodinated oil suspension chemoembolization were used in all 6 patients during TACE, and all of them experienced ARDS symptoms within 24-48 hours after TACE. However, no clear pathogenic bacteria were incubated in the sputum culture after the onset of the disease. Diffused exudative changes of both lungs were found in the chest X-ray, and the oxygenation index (PaO2/FiO2) was within 100-300 mmHg. The symptoms of 6 patients improved after 3-6 days of hormone therapy. CONCLUSION: In this study, we found that although the incidence of ARDS after TACE was low in the treatment for HCC, the symptoms after onset were serious, and the early hormone therapy may be beneficial to improve the prognosis and reduce mortality. Further research with larger samples is still needed to confirm the pathogenesis of ARDS after TACE in the treatment for HCC.

Effects of granulocyte colony-stimulating factor on repair of injured canine arteries.

BACKGROUND: Endothelial progenitor cells (EPCs) derived from bone marrow may differentiate into endothelial cells and participate in endothelial repair. These cells can be mobilized into peripheral blood by cytokines, including granulocyte colony-stimulating factor (G-CSF). In the present study, we investigated the effects of G-CSF on neointimal formation and restenosis in a canine model of arterial balloon injury. METHODS: Sixteen male beagle dogs were injected subcutaneously with 20 microg x kg(-1) x d(-1) recombinant human G-CSF (n = 8) or normal saline (n = 8) for 1 week. On the fifth day of treatment, the dogs underwent renal arterial angioplasty. At 8 weeks after arterial balloon injury, angiographic observations were made and injured arteries were processed for morphometric analysis of neointimal formation. RESULTS: Peripheral white blood cell counts were increased by 3.34-fold compared to baseline on the fifth day of administration of G-CSF. Angiographies revealed that one stenosis had occurred among the eight injured renal arteries from dogs treated with G-CSF, whereas all injured renal arteries from dogs treated with normal saline remained patent. The mean extent of stenosis among injured arteries was 18.3% +/- 17.9% in the G-CSF treated group compared to 12.5% +/- 7.6% in the saline treated control group (P = 0.10). G-CSF treatment slightly increased neointimal thickness (0.42 +/- 0.15 mm vs 0.25 +/- 0.06 mm, P = 0.08) with an intima to media ratio of 0.83 +/- 0.49 vs 0.54 +/- 0.18 (P = 0.11). CONCLUSIONS: G-CSF treatment does not attenuate neointimal hyperplasia and restenosis formation in a canine model of renal arterial injury, suggesting that the therapeutic strategy for preventing restenosis by stem cell mobilization should be investigated further.

Theoretical study on stabilization mechanisms of nitrate esters using aromatic amines as stabilizers.

The propellants of nitrate esters can be stabilized by some aromatic amines practically. To probe the mechanism of this phenomenon, we performed DFT calculations on: (1) The decompositions of nitrate esters (with and without the catalysis of NO2) and (2) the reaction between the stabilizers and the nitro dioxide (NO2 is released during the storage of nitrate esters). The structures on the reaction paths (reactants, intermediates and products) were optimized at the (U)B3LYP/6-31G** level. It was shown that NO2 lowers the activation energy barrier in the decomposition of nitrate ester by 11.82-17.86kJ/mol and efficiently catalyzes the rupture of ONO2 bond. However, the aromatic amines, typical stabilizers for nitrate esters, can easily eliminate NO2 with activation barriers as low as 27-113kJ/mol (with one exception of 128kJ/mol). These values are, for most cases, lower or much lower than the activation energy barriers for reactions between nitrate esters and NO2 (127-137kJ/mol). Consequently, the stabilizers can block the NO2 catalysis for the decompositions of nitrate esters.

Variation in complementary and alternative medicine (CAM) use across racial/ethnic groups and the development of ethnic-specific measures of CAM use.

OBJECTIVES: The use of complementary and alternative medicine (CAM) is likely to vary among racial/ethnic groups because its use is related to cultural and health beliefs. Understanding patterns of CAM use among ethnic groups could inform clinical practice and the study of CAM use in a diverse population. The authors compared CAM use among Asian-Americans, American Indians, African Americans, Latinos, whites, and other racial/ethnic groups in order to develop ethnic-specific measures of CAM use and explore factors associated with such CAM use across ethnic groups. DESIGN: A cross-sectional survey of a sample of 9187 adults representative of the California population was performed. OUTCOME MEASURES: Ethnic-specific constructs for Asian-Americans, American Indians, African Americans, Latinos, and whites were devised. RESULTS: The authors identified ethnic-specific CAM modalities for each ethnic group. Demographic and clinical factors associated with use of ethnic-specific CAM differed from the predictors of overall CAM use in the general population and varied by ethnicity. CONCLUSIONS: Patterns of CAM use and ethnic-specific CAM use vary across racial/ethnic groups. Evaluation of CAM use in ethnically diverse populations should recognize ethnic-specific modalities and variation across ethnicity.

[The adolescent physical exercise behavior-psychological measurement scale on the Chinese version and its reliability and validity study].

OBJECTIVE: To develop a suitable physical exercise behavior-psychological scale for the Chinese adolescents and to evaluate its validity and reliability. METHODS: A total of 3600 junior students were recruited and tested through multistage sampling method. Reliability was assessed, using Cronbach's α and split-half reliability; while exploratory factor analysis and confirmatory factor analysis were used to test its validity, with entries-dimension correlation coefficient (IIC), correlation coefficient between the scores and the dimension, the dimension of correlation coefficient test content validity. RESULTS: The internal consistency reliabilities for total scale score (Cronbach's α = 0.888), Cronbach's α of four domains were 0.880, 0.706, 0.552 and 0.839, respectively. The four-domain split-efficacy reliabilities were ranged between 0.559 and 0.876. Data from the exploratory factor analysis revealed the following dimensions: the entries were all inclusive; the cumulative contribution rate was more than 40%. RESULTS: from the confirmatory factor analysis showed that the absolute fit measures of GFI = 0.972, AGFI = 0.958, RMSEA = 0.032 (90%CI: 0.030 - 0.034) could satisfy the condition while the model fit was better. The results of IIC showed: in the four dimensions, and the contained entries between Spearman correlation coefficient range were 0.396 - 0.700, 0.470 - 0.709, 0.696 - 0.771 and 0.665 - 0.813, while other dimensions from weak to moderate relationships, the r value range was from 0.386 to 0.935. With the change of the phase changing process, decision balance, self-efficacy scores were differently prompting the health-related intervention periodically and pertinently. CONCLUSION: The reliability and validity of the 'Adolescent physical exercise behavior-psychological scales (Chinese version) ' were good, and could be used to measure the adolescent's physical training behavior-psychological conditions.