New technology for preparing energetic materials by nanofiltration membrane (NF): rapid and efficient preparation of high-purity ammonium dinitramide (ADN).

The development of environment-friendly and non-toxic green energetic materials and their safe, environmentally friendly, and economical production is very important to the national economy and national security. As an innovative, efficient, and environmentally friendly energetic material, the preferred preparation method of ammonium dinitramide (ADN) is the nitro-sulfur mixed acid method, which has the advantages of high yield, simple method, and easy access to raw materials. However, the large number of inorganic salt ions introduced by this method limits the large-scale production of ADN. Nanofiltration (NF) has been widely used in various industrial processes as a separation method with high separation efficiency and simple operation. In this study, NF was used for the desalination and purification of ADN synthesized by the mixed acid method. The effects of NF types, operation process (pressure, temperature, and feed solution concentration) on desalination efficiency, and membrane flux during purification were examined. The results showed that 600D NF could achieve the efficient desalination and purification of ADN. It was verified that the highest desalination and purification efficiency was achieved at 2 MPa pressure, 25 °C, and 1 time dilution of the feed solution, and the membrane flux of the desalination and purification process was stable. Under the optimized process conditions, the removal rate of inorganic salts and other impurities reached 99% (which can be recycled), the purity of ADN reached 99.8%, and the recovery rate reached 99%. This process has the potential for the large-scale production of ADN and provides a new process for the safe, efficient, and cheap preparation of energetic materials.

Overexpression of LMP-1 Decreases Apoptosis in Human Nucleus Pulposus Cells via Suppressing the NF-κB Signaling Pathway.

Intervertebral disc degeneration (IDD) is a prevalent disease characterized by low back pain. Increasing extracellular matrix (ECM) synthesis and decreasing nucleus pulposus cell (NPC) apoptosis are promising strategies to recover degenerated NP. LIM mineralization protein- (LMP-) 1 has anti-inflammatory potential and is a promising gene target for the treatment of NP degeneration. In this study, we measured the expression of LMP-1 in the NP of patients. Then, we constructed LMP-1-overexpressing NPCs using lentiviral vectors and investigated the effects of LMP-1 on cell proliferation, apoptosis, and ECM synthesis in NPCs. The results showed that LMP-1 was highly expressed in the NP of patients. LMP-1 overexpression significantly increased proliferation and decreased apoptosis in NPCs. The expression of collagen II and sulfated glycosaminoglycan (sGAG) in NPCs was also upregulated after LMP-1 was overexpressed. Moreover, we demonstrated that LMP-1 decreased apoptosis of NPCs by inhibiting NF-κB signaling activation. These findings suggest that LMP-1 plays an essential role in mediating apoptosis in NPCs by regulating NF-κB signaling and can be used as a gene target for the treatment of IDD.

7,8-dihydroxycoumarin has a dual mechanism of action in hepatic ischemia reperfusion injury.

The present study was designed to investigate the protective effect of 7,8-dihydroxycoumarin on hepatic ischemia/reperfusion (I/R) injury in the rats. The rats were divided in three groups of 10 each; normal control, untreated and the 7,8-dihydroxycoumarin treatment groups. The rats in the treatment group received 7,8-dihydroxycoumarin at doses of 15 mg/kg body weight 1 h prior to ischemia and then daily for 2 days. The animals were sacrificed after 1, 12, 24, 36, and 48 h of reperfusion. The results revealed that 7,8-dihydroxycoumarin protected the liver against I/R injury via inhibition of inflammatory response at the early stage (0-24 h). However, in 7,8-dihydroxycoumarin treatment group autophagy was inhibited resulting in intensified I/R injury following 36 h of reperfusion. 7,8-dihydroxycoumarin treatment caused reduction in the level of serum aminotransferase, liver inflammatory cytokines and showed minor liver histopathologic alterations. However, after 36 h of reperfusion treatment group showed similar I/R injury as that of untreated group. It was observed that 7,8-dihydroxycoumarin enhanced the activation of mitogen-activated protein kinase, decreased nuclear release of high-mobility group box 1 and production of inflammatory cytokines. After 36 h 7,8-dihydroxycoumarin promoted hepatic injury through suppression of autophagy and induction of hepatic apoptosis. Therefore, 7,8-dihydroxycoumarin exhibits inhibitory effect on hepatic ischemia during 0-24 h but causes its promotion after 36 h.

[Establishment and application of nested real-time quantitative polymerase chain reaction assay for detection of hepatitis B virus covalently closed circular DNA].

OBJECTIVE: To establish a nested real-time quantitative polymerase chain reaction (PCR) assay for detection of hepatitis B virus covalently closed circular DNA in PBMC( peripheral blood monocyte) and MMNC (marrow monocyte). METHODS: Based on the structural differences between HBVcccDNA and HBV rcDNA, two pairs of specific primers spanned the gap of the positive and negative chains and a specific TaqMan probe situated downstream were designed. To remove rcDNA, cccDNA was processed by Mung Bean Nuclease,and then amplified by nested real-time quantitative PCR using a pair of outer primers and a pair of inner primers. According to the standard preparation, cccDNA levels of specimen were calculated. RESULTS: We have established a nested real-time fluorescent quantitative PCR method for HBV cccDNA successfully, and the linear range is from 5.0 x 10(2) to 3. 9 x 10(7) copies per milliliter. Of the 25 PBMC samples and 7 MMNC samples of the chronic hepatitis B or liver cirrhosis patients, 3 MMNC samples and 9 PBMC samples were HBV cccDNA positive, while all of the 21 healthy donator blood PBMC samples were negative. CONCLUSIONS: The nested real-time fluorescent quantitative PCR method may be applied to detect HBVcccDNA level in PBMC and MMNC. HBVcccDNA can be detected in PBMC and MMNC.

Nested real-time quantitative polymerase chain reaction assay for detection of hepatitis B virus covalently closed circular DNA.

BACKGROUND: Successful treatment of hepatitis B can be achieved only if the template for hepatitis B virus (HBV) DNA replication, the covalently closed circular HBV DNA (cccDNA) can be completely cleared. To date, detecting cccDNA remains clinically challenging. The purpose of this study was to develop a nested real-time quantitative polymerase chain reaction (PCR) assay for detecting HBV cccDNA in peripheral blood mononuclear cells (PBMCs) and bone marrow mononuclear cells (MMNCs). METHODS: Based on the structural differences between HBV cccDNA and HBV relaxed circular DNA (rcDNA), two pairs of primers were synthesized as well as a downstream TaqMan probe. Blood and bone marrow samples were collected from hepatitis B patients and healthy controls. To remove rcDNA, samples were incubated with mung bean nuclease and the resultant purified HBV cccDNA was then amplified by nested real-time fluorescence quantitative PCR. The cccDNA levels were calculated using a positive standard. RESULTS: The nested real-time fluorescence quantitative PCR method for HBV cccDNA was successful, with a linear range of 3.0 × 10(2) copies/ml to 3.9 × 10(8) copies/ml. Of the 25 PBMC samples and 7 MMNC samples obtained from chronic hepatitis B or liver cirrhosis patients, 3 MMNC samples and 9 PBMC samples were positive for HBV cccDNA, while all of the 21 PBMC samples from healthy controls were negative. CONCLUSION: The nested real-time fluorescence quantitative PCR may be used as an important tool for detecting cccDNA in hepatitis B patients.

[Reactive oxygen species and mitochondrial membrane potential changes in leukemia cells during 6-gingerol induced apoptosis].

OBJECTIVE: To observe the effects of 6-gingerol on reactive oxygen species (ROS) and mitochondrial membrane potential(deltapsim) of chronic myeloid leukemia K562 cells and human acute T lymphoblastic leukemia MOLT4 cells, to investigate the role of mitochondrial pathway in the signal transduction of leukemia cell. METHODS: With different concentrations of 6-gingerol treatment, using 2,7-dichloro fluoresceinciactate (DCFH-DA) as ROS probe, rhodamine-123 as deltapsim probe, the levels of ROS and deltapsim of K562 cells and MOLT4 cells were tested by flow cytomentry. RESULTS: After treated with 6-gingerol, the ROS levels of K562 cells were significantly higher than control group (P < 0.01), while the deltapsim were significantly lower than control group (P < 0.01), and the ROS levels of MOLT4 cells were significantly higher than control group (P < 0.05). CONCLUSIONS: 6-gingerol can significantly increase ROS levels of K562 cells and MOLT4 cells, decrease deltapsim of K562 cells,induce apoptosis of leukemia cells by mitochondrial pathway.

Sonochemical fabrication and characterization of ceria (CeO2) nanowires.

Ceria (CeO2) nanowires have been successfully synthesized by a sonochemical method in ambient air and alkali aqueous solution from CeO2 nanoparticles without using any templates. The results showed that both alkali concentration and ultrasonic irradiation played critical roles in the formation of the nanowires. The crystalline structure and dimensions of the nanowires were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED). The UV-visible absorption spectrum result showed that the products had conspicuous shape-specific effect. Microstructural analysis in HRTEM revealed that the preferential growth direction of CeO2 nanowires was [110]. Moreover, the catalytic activity of Au/CeO2 using CeO2 nanowires as support for CO conversion was higher than that obtained using bulk CeO2 as support.

A study of thoria on the surface of gamma-Al2O3.

The dispersion of thoria on the surface of gamma-Al2O3 and the surface properties of ThO2/gamma-Al2O3 samples, as well as the influence of the loading amount of thoria on the reduction behavior of copper oxide species, have been studied using XRD, XPS, FTIR, and TPR. The results indicate that the dispersion capacity of thoria, like that of ceria, is much lower than for two other tetravalent metal oxides, zirconia and titania, and the surface adsorption amount of the carbonyl compound and H2O slightly increases with increasing thoria loading. The different thoria loadings can influence the reduction behavior of the dispersed copper oxide by comparing the TPR results of CuO/ThO2/gamma-Al2O3 samples. In addition, the lower dispersion capacities of thoria and ceria on gamma-Al2O3 are tentatively discussed by considering the structural stability of the two oxides.