Development of a D-D neutron spectrum detector based on helium-3 proportional counter.

Deuterium-deuterium (D-D) neutron spectrum diagnostics in tokamaks are a challenging task with current technologies. To address this issue, we designed and tested a fast and compact helium-3 proportional counter with a diameter of 2.5 cm and an effective length of 15 cm and using Kr as a stopping gas. The detector achieved a resolution of 96 keV for 2.406 MeV neutrons with a pulse shaping of 2 µs. Test results indicate that this detector has the potential to form a D-D neutron spectrometer for tokamaks, composed of detector arrays.

Electrospray-Assisted Fabrication of Dextran-Whey Protein Isolation Microcapsules for the Encapsulation of Selenium-Enriched Peptide.

Selenium-enriched peptide (SP, selenopeptide) is an excellent organic selenium supplement that has attracted increasing attention due to its superior physiological effects. In this study, dextran-whey protein isolation-SP (DX-WPI-SP) microcapsules were fabricated via high-voltage electrospraying technology. The results of preparation process optimization showed that the optimized preparation process parameters were 6% DX (w/v), feeding rate Q = 1 mL/h, voltage U = 15 kV, and receiving distance H = 15 cm. When the content of WPI (w/v) was 4-8%, the average diameter of the as-prepared microcapsules was no more than 45 µm, and the loading rate for SP ranged from ~46% to ~37%. The DX-WPI-SP microcapsules displayed excellent antioxidant capacity. The thermal stability of the microencapsulated SP was improved, which was attributed to the protective effects of the wall materials for SP. The release performance was investigated to disclose the sustained-release capacity of the carrier under different pH values and an in-vitro-simulated digestion environment. The digested microcapsule solution showed negligible influence on the cellular cytotoxicity of Caco-2 cells. Overall, our work provides a facile strategy of electrospraying microcapsules for the functional encapsulation of SP and witnesses a broad prospect that the DX-WPI-SP microcapsules can exhibit great potential in the food processing field.

Fabrication of immobilized lipases for efficient preparation of 1,3-dioleoyl-2-palmitoylglycerol.

This study aims to fabricate immobilized lipases for efficient preparation of 1,3-dioleoyl-2-palmitoyl-glycerol (OPO) through acidolysis of glycerol tripalmitate (PPP). Twelve (three types) supports and five lipases were studied carefully. Among them, the immobilized Thermomyces lanuginosa lipase (TLL) samples exhibited overall better performance than that of other immobilized lipases. Particularly, organic groups functionalized SBA-15 (R-SBA-15) supported TLL (TLL@R-SBA-15) samples gave PPP conversion from 97.70 to 99.00 % and OPO content from 59.52 to 64.73 %. After optimization, PPP conversion up to 99.07 %, OPO content 73.15 % and sn-2 palmitic acid content 90.09 % were obtained with TLL@C18H37-SBA-15 as catalyst. Moreover, TLL@C18H37-SBA-15 exhibited better acidolysis performance from 50 °C than that from 60 to 80 °C, which helped inhibit acyl migration. In addition, after 5 cycles of reuse, TLL@C18H37-SBA-15 retained 81.04 % (based on OPO content) and 98.88 % (based on sn-2 palmitic acid content) of its initial activity, indicating it had an attractive prospect in future applications.

Robust Electrospinning-Constructed Cellulose Acetate@Anthocyanin Ultrafine Fibers: Synthesis, Characterization, and Controlled Release Properties.

Anthocyanin has attracted increasing attention due to its superior biological activity. However, the inherently poor stability of anthocyanin limits its practical applications. In this study, a fast and straightforward method was developed to improve the stability of anthocyanin. Cellulose acetate ultrafine fiber-loaded anthocyanin (CA@Anthocyanin UFs) was prepared by robust electrospinning, and the potential application of cellulose acetate ultrafine fibers (CA UFs) as a bioactive substance delivery system was comprehensively investigated. The experimental results showed that CA@Anthocyanin UFs had protective effects on anthocyanin against temperature, light, and pH. The results of the artificially simulated gastric fluid (pH = 2.0) indicated that the CA@Anthocyanin UFs had a controllable release influence on anthocyanin. A 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay suggested that the CA@Anthocyanin UFs still had an excellent antioxidant activity similar to anthocyanin. This work demonstrated the potential application of robust electrospinning-constructed cellulose acetate ultrafine fibers in bioactive substance delivery and controlled release systems, as well as its prospects in green packaging due to the nature of this environmentally friendly composite.

Hard x-ray spectrometer with high time and energy resolution on HL-2A tokamak.

A hard x-ray spectrometer based on a φ25 × 25 mm2 LaBr3 scintillator has been developed to measure the runaway electron bremsstrahlung. Simulation results by GEANT4 show that x rays with an energy of 15 MeV can be effectively detected. In order to tolerate a high count rate, a self-made fast shaping amplifier is used to process the detector output into a fast bipolar pulse. The tested energy resolution, which was 3.4% for Cs-137 662 keV gamma rays, shows that the shaping amplifier does not significantly degrade the energy resolution. The results of the HL-2A discharge show that the maximum count rate can reach 2 MHz, and the time resolution of the spectrometer can reach the millisecond level.

Structural and mechanistic insights into starch microgel/anthocyanin complex assembly and controlled release performance.

We report a self-assembly method for the fabrication of multilayer-starch-based microgels used for anthocyanin encapsulation. Alcohol-heating treatment and ionization reactions were employed to reduce the crystallinity of starch and introduce ionic groups on the molecule to further cross-link it with sodium trimetaphosphate and produce a starch microgel. The molecular interactions between the starch and the anthocyanins facilitated the anthocyanin encapsulation and the starch-microgel/anthocyanin complexes with one, two, and three self-assembled layers were obtained. The Lay-1 microgel exhibited an encapsulation efficiency of 50.1% when the anthocyanin concentration, cross-linking starch concentration, contact time, and temperature were 0.25 mg/mL, 1.5 mg/mL, 3 h, and 40 °C, respectively. An increase in the number of layers resulted in a more compact microgel structure with the zeta potential presenting variations upon structural changes. Furthermore, the encapsulated anthocyanins presented a slow release from Lay-1, while the multilayered microgels (Lay-2 and Lay-3) displayed outstanding encapsulation stability. This study gives an insight on the encapsulation and release of anthocyanins by starch microgels, and provides a novel strategy for the design of starch-based encapsulation materials presenting great stability.

[Influence of Jiangu decoction on peroxisome proliferator-activated receptor (PPAR) in the femoral head of rabbits with steroid-induced femoral head necrosis].

OBJECTIVE: The Jiangu decoction is used in the treatment of steroid-induced femoral head necrosis in clinical experiences, which has functions of tonifying kidney and activating blood, and invigorating spleen to remove phlegm. The decoction is mainly composed of Radix Polygoni Multiflori, Rhizoma alismatis Rhizoma Drynariae, haw, medlar, Radix Astragali, radix rehmanniae, angelica, Radix Codonopsis, radix salviae miltiorrhizae, Fructus Ligustri Lucidi, licorice, pharmaceutical composition. This study was designed to investigate the influence of Jiangu decoction on peroxisome proliferator-activated receptor gamma (PPARgamma) in the femoral head of rabbits with steroid-induced femoral head necrosis. METHODS: Eighteen adult SPF healthy New Zealand rabbits were divided into 3 groups: control group, model group, Jiangu decoction group. The rabbits of Jiangu decoction group orally received Jiangu decoction suspension with a dose of 10 ml/kg each day and the drug content was 0.719 g/ml. The rabbits in control and model groups were given saline with a dose of 10 ml/kg. The methylprednisolone sodium succinate was injected intramuscularly into left leg with a dose of 40 mg/kg. Then the rabbits were fed continuously for 3 weeks. The glucocorticoid levels, PPARgamma and plasma glucocorticoid levels in the femoral head were measured before and after modeling. RESULTS: Before model established, the plasma glucocorticoid levels had no significant difference among three groups (P=0.301). At 3 weeks after model established,the plasma glucocorticoid level of rabbits in model group increased compared to the control group (P=0.001); and the plasma glucocorticoid level of rabbits in Jiangu decoction group decreased compared with model group (P=0.001). The glucocorticoid level in the local femoral head of rabbits in model group increased compared to the control group (P=0.001); and the glucocorticoid level in the local femoral head of rabbits in Jiangu decoction group decreased compared with model group (P=0.001). The PPARgamma level in the local femoral head of rabbits in model group increased compared to the control group (P=0.018);and the PPARgamma level in the local femoral head of rabbits in Jiangu decoction group decreased compared with model group (P=0.033). CONCLUSION: The Jiangu decoction is effective to inhibit the femoral head adipogenic differentiation by decrease the PPAR content, so as to prevent and treat steroid-induced femoral head necrosis.