Investigation into the flotation response of refractory molybdenum ore to depressant mixtures:A case study

In this paper, bulk flotation followed by separation was investigated to concentrate purified molybdenite product from Jinduicheng molybdenum ores(Shanxi province, China). The bench scale tests mainly focussed on separation of molybdenite from other sulfide minerals using the new type of depressants.The effect of each single depressant, including organic depressant-modified dextrin(MD), P-Nokes reagent(PN) and sodium trithiocarbonate(ST), and their mixtures on galena, chalcopyrite and other sulfide ores, was examined in turn by changing the concentrations used in cleaner flotation tests. Closed circuit experiments were carried out under the optimal condition and satisfying recovery and grade of molybdenite concentrate could be achieved(86.294% and 53.157%, respectively). A potential reagent regime was developed, with more environmental friendly and more economical advantages due to the introduction of modified dextrin.

Effects of appendectomy and oral tolerance on dextran sulfate sodium colitis

AIM： To evaluate the concomitant effects of appendec- tomy and oral tolerance on colitis.METHODS： Delayed-type hypersensitivity （DTH） was investigated at a 7-d interval after ovalbumin （OVA） ad- ministration and immunization under normal and colitis conditions in appendectomized or sham-operated mice. Pathological scores for the colon were graded after in- gestion of colon-extracted protein （CEP） and induction of dextran sulfate sodium （DSS） colitis in appendecto- mized or sham-operated mice. Thereafter, Thl and Th2 in Peyer＇s patches and spleen lymphocytes were de- tected in CEP-treated and bovine serum albumin （BSA）-treated control mice.RESULTS： In appendectomized mice, DTH was not inhibited at day 7 after OVA administration and at the initial phase of DSS colitis, whereas it was inhibited at day 14 and day 21. However, in sham-operated mice, it was inhibited during the whole procedure and the onset of DSS colitis. The protective role of CEP against DSScolitis was present in sham-operated mice, with pre- dominant improvement of colonic pathological changes, while vanished in the appendectomized mice. A shift from Thl to Th2 in Peyer＇s patches resulted from a de- crease of Thl cells with the ingestion of CEP. Compared with BSA in the sham-operated group, no predominant changes were observed in the appendectomized mice.CONCLUSION： Appendectomy interferes with the pro- tective role of CEP in DSS colitis via a shift from Th2 to Thl during oral tolerance induction.

Stability of freeze-dried pH-responsive dextrin nanogels containing doxorubicin

Induction of non-specific toxicities by doxorubicin(DOX) has restricted conventional DOXbased chemotherapy. p H-responsive dextrin nanogels(DNGs) have been fabricated in order to incorporate and deliver DOX to specific(targeted) sites. However, adequate stability studies of DOX-loaded DNGs are required for selection of storage conditions. The aim of this study was therefore to evaluate the accelerated(25 °C/60% RH) and long-term(5 °C) stability of DNGs prepared with formaldehyde(FDNGs) and glyoxal(GDNGs) as cross-linker by determining the change in their physicochemical properties. The mean diameter decreased with time during long-term storage. The drug content between freshly prepared(initial day) and after storage at 5 °C for 180 days of DOX-loaded FDNGs and DOX-loaded GDNGs was not significantly different(p > 0.05), but decreased after storage under the accelerated condition. The release of DOX from all DNGs was pH-dependent. However, DNGs kept under the accelerated condition showed higher amount of DOX release than those stored at 5 °C and the freshly prepared ones. The results indicate that the stability of DNGs could be improved by their storage at 5 °C.

Effects of Dietary Carbohydrate-to-Lipid Ratio on the Growth Performance and Feed Utilization of Juvenile Turbot(Scophthalmus maximus)

A 9-week feeding trial was conducted to investigate the effects of dietary carbohydrate to lipid ratio(CHO:LIP) on the growth performance and feed utilization of juvenile turbot Scophthalmus maximus(initial body weight 8.75 g ± 0.04 g). Four isonitrogenous and isoenergetic low protein level(39%) diets were formulated with increasing ratios of dietary carbohydrate to lipid(2:18, 6:18, 18:12 and 28:6). A high protein level(50%) diet with the 2:12 ratio of carbohydrate to lipid was used as the control. Results showed that the survival rate, contents of moisture, crude protein and ash in muscle were not significantly affected by dietary treatments. With the dietary CHO:LIP ratio increased from 2:18 to 18:12, weight gain rate significantly increased(P < 0.05). Higher dietary CHO:LIP ratio(28:6) resulted in the significantly decreased weight gain rate(P < 0.05). Meanwhile, this treatment also resulted in the highest daily feed intake and liver glycogen content, as well as the lowest feed efficiency(P < 0.05). Muscle glycogen content in fish fed the diet with 2:12 or 2:18 CHO:LIP ratio was significantly lower than those fed with the other three diets(P < 0.05). The present results confirmed that the juvenile turbot can utilize carbohydrate. Furthermore, the appropriate ratio of dietary carbohydrate to lipid was important to the growth and feed utilization of turbot. The proper CHO:LIP ratio based on the growth performance in the present study was determined to be 18:12 when the dietary protein level was 39%.

环糊精化学的产生发展及应用

早在1891年由Villies首先发现的环糊精(Cyclo-dextrin,以下简称CD),在二十世纪六十年代以后,又重新露头角,它是第一个被发现能包络其它有机分子的天然或半合成的大环有机化合物,是优良的人工酶模型。有关它的研究工作,在七十年代由于日新月异的发展使之达到了新的高峰。正由于其结构上的特点,特殊的功能和生产上的开发,故在医药、农业、食品、催化合成和分拆分离技术等方面有着广泛的用途和广阔的开发前景,现已独立地形成一门新兴的学科——环糊精化学。

Self-Assembled Dextrin Nanogel as Curcumin Delivery System

Curcumin is a natural polyphenol with anti-oxidative, anti-inflammatory and anti-cancer properties. Its therapeutic potential is substantially hindered by the rather low water solubility and bioavailability, hence the need for suitable carriers. In this study, we show that self-assembled nanogels obtained from hydrophobically modified dextrin are effective curcumin nanocarriers. The stability and loading efficiency of curcumin-loaded nanogel depends on the nanogel/curcumin ratio. Higher stability of the formulation is achieved in water than in PBS buffer, as evaluated by dynamic light scattering and fluorescence measurements. The in vitro release profile, using sink conditions, indicates that dextrin nanogel may perform as a suitable carrier for the controlled release of curcumin. Biological activity of curcumin-loaded nanogel in HeLa cell cultures was assessed using the MTS assay.

THE STUDY ON SYNTHESIS OF ULTRAFINE_α Al_2O_3 BYLOW TEMPERATURE COMBUSTION PROCESS

Based on thelow temperaturecombustion synthesisof α Al2 O3 from aluminum nitrate,the effectsofthe additives on the formation and particle properties of α Al2 O3 werestudied by XRDand SEM,theinitialstudy on the manometer α Al2 O3 synthesisby LCSwas done, α Al2 O3 withtheparticlesize50 ～80 NM wasgot under properconditions.

SYNERGISTIC EFFECT OF MINERAL SURFACE CONSTITUENTS IN DEXTRIN ADSORPTION

As part of a systematic research on the interaction mechanism between polysaccharides and mineral surfaces, ive extend the studies on dextrin adsorption to real minerals such as oxides and salt-type minerals, based on previous studies of model systems {surface-modified quartz ). The minerals tested include hematite, rutile, fluorite, calcite, apatite, etc. It is observed that dextrin adsorption on these minerals is strongly pH-depen-dent, with adsorption maxima appearing at pH values around the isoelec-tric points of the minerals, indicating interactions zvith surface metal hy-droxide species. X-ray photoelectron spectroscopy (XPS) measurements re-veal electronic binding energy shifts or Auger parameter changes of miner-al surface elements after dextrin adsorption , pointing to a chemical mecha-nism of interaction. Furthermore, it is observed that the reaction of miner-als with moderate amounts of fatty acids prior to dextrin addition results in an increase in dextrin adsorption, whereas excessive fatty acids do the opposite. Combined with our previous studies, it is concluded from the ex-perimental observations that although surface hydrophobic species alone do not have any effect on dextrin adsorption, they synergistically enhance the adsorption when present together with surface metallic sites.

Safety assessment of dextrin hydrogel adhesion barrier (AdSpray®) for elective laparoscopic cholecystectomy

Objective:Adhesion barriers have not traditionally been used during laparoscopic cholecystectomy(lapchole),and so there are no data confirming the safety of the dextrin hydrogel adhesion barrier(AdSpray®)for the use during lap-chole.The aim of this prospective study is to investigate the safety of AdSpray®for elective lap-chole.Methods:Between July 2019 and March 2021,we conducted a prospective study at Saiseikai Kumamoto Hospital to assess the safety of applying AdSpray®around the hepatoduodenal ligament,liver surface,and port area after extraction of the gallbladder during elective lap-chole.We assessed patient morbidity,mortality,and laboratory data on postoperative day 1 and at the outpatient follow-up visit.Results:A total of 100 patients(43 men,57 women)received AdSpray®application during elective lapchole at our institution.The mean patient age was 56.5±14.8 y,and the mean body mass index was 25.1±4.8 kg/m2.Preoperative gallbladder drainage was performed in 3(3.0%)patients as conservative treatment for acute cholecystitis.The mean operative time was 91.7±35.1 min,and the median blood loss was 5 mL(range,5e120 mL).Intraoperative gallbladder perforation was observed in 4.0%of patients(n=4).There was no intraoperative bile duct injury.One(1.0%)patient had a postoperative subhepatic fluid collection without bacterial infection.The mean white blood cell count and C-reactive protein level was significantly elevated on postoperative day 1 but returned to preoperative levels by the time of the follow-up visit.All patients were successfully discharged after surgery,and the median postoperative hospital stay was 2 d(range,2e9 d).Conclusion:Applying AdSpray®during elective lap-chole is safe,with an acceptable rate of postoperative complications.

Utilization Starch of Avocado Seed （Persea Americana Mill.） as a Raw Material for Dextrin

Starch ofavocado seeds can be used as an alternative source of starch because it contains 80.1% starch. Natural starch can be made into a modified starch, for example dextrin. Dextrin can be made by using acid or enzyme hydrolysis. The purposes of this research were determine the concentration of hydrochloric acid （HCl）, the temperature and heating timein the optimum process of hydrolysis of starch into dextrin and to determine the quality of the resulting product dextrin terms of Indonesian National Standard 01-2593-1992. The methode was used in this research is hydrolisis with hydrochloric acid （HCl）. The results processing into starch avocado seed yield is 23.15%. HCl concentration, temperature and heating time significantly affect the value of dextrose equivalent （DE）, viscosity and part soluble in cold water. There is interaction between HCl concentration, temperature and heating time on the value of DE, viscosity and part soluble in cold water. Optimum conditions of process was obtained at a concentration of 0.15 N HCl, 30 minutes heating time and heating temperature of 90 ℃. Dextrose equivalent （DE） value is 19.61%. The value of solubility in cold water is 90.19%. Viscosity value is 1.61 ° E. Dextrin is not accordance with the standards of quality parameters Indonesian National Standard 01-2593-1992. Dextrin produced should be applied to non-food industry.

Microencapsulation of Fish Oil by Simple Coacervation of Hydroxypropyl Methylcellulose

To improve the oxidative stability and application of fish oil, it was microencapsulated by simple coacervation followed by spray drying. Simple coacervation took place by adding malt dextrin into the emulsion of fish oil and hydroxypropyl methylcellulose （HPMC） solution. Influences of several process parameters on the microencapsulation were evaluated and the oxidative stability and microstructure of microcapsules were analyzed. Results showed that the coacervation could be observed only when dextrose equivalent value （DE value） of malt dextrin, concentration of HPMC solution and fish oil percentage in microcapsules were no more than 20. 5% and 40%, respectively. Moreover, microencapsulation efficiency was higher at HPMC solution concentration of 4% and fish oil percentage of less than 30%. The oxidative stability of fish oil was improved by the microencapsulation and done best in the ease of replacing malt dextrin by 40% with acacia. Scanning electronic microscopic photographs showed that the microcapsule obtained was a round, smooth and hollow microcapsule with its wall made up of innumerable small and solid submicrocapsules with the core of fish oil.

Ethylene Oligomerization by 8-Aminoquinoline Nickel Dichloride Complex Supported on β-Cyclodextrin

Cyclodextrin was pretreated by methylaluminoxane (MAO) and subsequently reacted with 8 aminoquinoline nickel dichloride complex to yield the supported catalyst, which was characterized by ICP, IR and XPS methods. Using MAO as cocatalyst, the catalytic activity of this supported catalyst was investigated at various reaction temperature and Al/Ni molecular ratio. The results showed that, despite possessing a number of polar groups, the supported catalyst displayed relatively high activity over 1×10 5 g ethylene/(mol Ni·h) under mild conditions.

Preparation of high-quality resistant dextrin through pyrodextrin by a multienzyme complex

As a soluble food raw material with a low calorie content,resistant dextrin (RD) has broad application prospects in the food industry.Branching enzymes (BEs),as a key enzyme for RD preparation,can break the α-1,4 glycosidic bonds of donor chains and reconstruct the cleaved chains to acceptor chains through the α-1,6 glycosidic bonds.BEs with high transglucosidic activity toward amylopectin and short-chain substrates are urgently needed to increase the quality of RD.Herein,BE derived from Thermuobifida fusca (TfBE) was mined and characterized.The optimal temperature and pH of the TfBE were 40 ℃ and 6.5,respectively.A total of 1500 U/g substrate TfBE reacted with 20% (w/v) pyrodextrin for 12 h,the ratio of α-1,4 to α-1,6 glycosidic bonds was changed from 3.52:1 to 2.33:1,and the content of enzyme-resistant components notably increased from 44.0% to 53.8%.Furthermore,to make full use of receptor chains and small molecular sugars in the reaction system,a multienzyme complex of TfBE with T.fusca α-cyclodextrin glucosyltransferase (TfCGTase),TfBE with TfCGTase and Aspergillus nidulans α-glucosidase (AnGS) was used to further increase the enzyme resistance of RD from 44.0% to 65.3% and 70.6%,respectively.The developed multienzyme complex method could effectively contribute to improving the production quality and efficiency of RD preparation.

A networked swellable dextrin nanogels loading Bcl2 siRNA for melanoma tumor therapy

In this study, a networked swellable dextrin nanogel （DNG） was developed to achieve stimulated responsive small interfering RNA （siRNA） release for melanoma tumor therapy, siRNA was loaded into multidimensional dextrin nanogels by charge condensation with positive arginine residues modified in the dextrin backbone. Moreover, the networked nanogel was destroyed and loosened based on its bioreducible responsive property to control accelerated siRNA release in a bioreducible intracellular environment, while it remained stable under normal physiological conditions. We demonstrated that DNGs had swellable and disassembly properties under reduced buffer condition by transmission electron microscopy evaluation. The DNGs achieved an endosomal escape followed by selective release of the cargo into the cytosol by glutathione- triggered disassembly according to confocal microscopy observation. Thus, this smart nanogel achieved outstanding luciferase gene silencing efficiency and decreased Bcl2 protein expression in vitro and in vivo based on western blot analysis. Moreover, this nanogel exhibited superior anti-tumor activity for B16F10 xenograft tumors in C57BL/6 mice. These results demonstrate that the networked DNGs are effective for gene condensation and controlled intracellular release for tumor therapy. Overall, these findings suggest that this multidimensional swellable stimuli-responsive dextrin nanogel is an innovative strategy with great promise for gene and drug delivery.