• Preventive Nutrition and Food Science
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• v.2 no.1
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• pp.42-48
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• 1997

the exocrine pancreatic secretion is an important factor in the maintenance of zinc homeostasis. The daily pancreatic secretion of zinc into the gastrointestinal tract may be two or more times the daily dietary zinc intake. The objective of this study was to examine the distribution of proteins and zinc in pancreatic/biliary fluid following intraperitoneal {TEX}${65}^Zn${/TEX} injection into dietary prepared Sprague-Dawly rats. Distribution of zinc-binding protein in Sephadex G-75 subfractions showed a peak corresponding to the high molecular weight protein standard(<66kDa) in the pancreatic/biliary fluid. Zinc also was associated with the 29~35kDa mole-cular weight proteins. These are similar in size with zinc-containing enzymes, carboxypeptidase A and car-boxypeptidase B. A more remarkable small molecular weight fraction eluted beyond the 6.5kDa standard pro-tein peak. These results show the presence of small molecular weight compound in pancreatic/biliary fluid associated with zinc . These small molecular weight compounds may serve as zinc-binding ligands for the secretion of enogenous zinc into the duodenum. These findings suggest that these lignads may dissociate zinc in the duodenum thus making it vulnerable to complexation with phytate in the upper gastrointestinal tract rendering the zinc unavailable for reabsorption.

• Journal of the Korean Chemical Society
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• v.20 no.1
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• pp.59-72
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• 1976

The addition of one mole of zinc chloride to 2.33 moles of sodium borohydride in tetrahydrofuran at room temperature gave a clear chloride-free supernatant solution of zinc borohydride after stirring three days and standing at room temperature.The approximate rates and stoichiometry of the reaction of zinc borohydride with 54 selected organic compounds were determined in order to test the utility of the reagent as a selective reducing agent. Aldehydes and ketones were reduced rapidly, aromatic ketones being somewhat slowly, and the double bond of cinnamaldehyde was not attacked. Acyl halides were reduced rapidly within one hour, but acid anhydrides were reduced at a moderate rate. Carboxylic acids, both aliphatic and aromatic, were slowly reduced to alcoholic stage. Esters were inert to this reagent but a cyclic ester, γ-butyrolactone, was slowly attacked. Primary amides were reduced slowly with partial evolution of hydrogen, whereas tertiary amides underwent neither reduction nor hydrogen evolution. Epoxides and nitriles were all inert, as well as nitro, azo, and azoxy compounds. Cyclohexanone oxime and phenyl isocyanate were reduced slowly but pyridine was inert. Disulfide, sulfoxide, sulfone and sulfonic acids were stable to this reagent.

• Korean Chemical Engineering Research
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• v.48 no.2
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• pp.218-223
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• 2010

The zinc oxide thin film, which can be applied as the gas sensor of a semiconductor type, was grown on the silicon substrate by CFR(continuous flow reaction) method in this study. The growth property and the electrical property of the zinc oxide thin films synthesized by CFR method were also investigated. Zinc acetate solutions of 0.005~0.02 M were used as the precursor for the preparation of zinc oxide thin films. The size of ZnO particles consisted on the zinc oxide thin film increased not only with increasing concentration of precursor, but also the thickness of thin film increased. The growth rate of zinc oxide thin film by CFR method was proportionably depend on the concentration of precursor and the uniform ZnO thin film was prepared when zinc acetate of 0.01 M is used as the precursor. The charged currents on the zinc oxide thin films were obtained as its electrical property by I-V meter, and increased agree with increasing the thickness of zinc oxide thin film. Thus, it was concluded that the charged current on the zinc oxide thin film can be controlled with changing concentration of precursor solution in CFR method. The charged currents on the zinc oxide thin films also decreased when ZnO thin film is exposed under hydrogen sulfide of 500 ppmv at $300^{\circ}C$ for 5 min. From these results, it could be confirmed that the zinc oxide thin film prepared by CFR method can be used for the detection of sulfur compounds.

• The Journal of the Korean Society for Microbiology
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• v.34 no.6
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• pp.501-512
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• 1999

Gliotoxin, a fungal metabolite, is one of the epipolythiodioxopiperazine classes and has a variety of effects including immunomodulatory and apoptotic agents. This study is designed to evaluate the effect of zinc on gliotoxin-induced death of HL-60 cells. Here, we demonstrated that treatment of gliotoxin decreased cell viability in a dose and time-dependent manner. Gliotoxin-induced cell death was confirmed as apoptosis characterized by chromatin margination, fragmentation and ladder-pattern digestion of genomic DNA. Gliotoxin increased the proteolytic activities of caspase 3, 6, 8, and 9. Caspase-3 activation was further confirmed by the degradation of procaspase-3 and PARP in gliotoxin-treated HL-60 cells. Zinc compounds including $ZnCl_2$ and $ZnSO_4$ markedly inhibited gliotoxin-induced apoptosis in HL-60 cells (from 30% to 90%). Consistent with anti-apoptotic effects, zinc also suppressed the enzymatic activities of caspase-3 and -9 proteases. In addition, cleavage of both PARP and procaspase 3 in gliotoxin-treated HL-60 cells was inhibited by the addition of zinc compounds. We further demonstrated that expression of Fas ligand by gliotoxin was suppressed by zinc compounds. These data suggest that zinc may prevent gliotoxin-induced apoptosis via inhibition of Fas ligand expression as well as suppression of caspase family cysteine proteases-3 and -9 in HL-60 cells.

• Rapid Communication in Photoscience
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• v.2 no.2
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• pp.39-41
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• 2013

It is interesting to introduce viologen moiety into photoactive compounds such as porphyrin and anthracene in the study of supramolecular system such as pseudorotaxanes. For the construction of photoactive pseudorotaxane based on porphyrin-viologen-anthracene triad or its zinc derivative threaded with bis-p-phenylene-34-crown-10 macrocycle, porphyrin-viologen-anthracene triad 1 and its zinc derivative zinc porphyrin-viologen-anthracene triad 2 were prepared and their absorption and fluorescence spectral properties were measured.

• Journal of Microbiology
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• v.33 no.4
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• pp.302-306
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• 1995

E. coli was tested for their ability to uptake cadmium intracellularly, and the effect of zinc and calcium on cadmium toxicity to E. coli was observed. In addition, the effect of zinc and calcium on the uptake of cadimium was also studied. This study showed that living E. coli cells took up more cadmium than the dead cells. E. coli in the log phase uptake cadimiumm more actively than E. coli in the stationary phase. These results suggested that there may be metabolic reactions or compounds which encourage the uptake of cadimium. This study also showed that cadimium was sequestered by cell components of which molecular weight is about 30,000. Adding of zinc and calcium chloride reduced cadmium toxicity in E. coli and encouraged intracellular uptake by E coli. However adding of heavy metal solutions helped the microorganisms to adsorb more cadmium. Extremely high or low concentrations of zinc, however, did not affect cell viability.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.314-314
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• 2008

The low temperature sintering and the dielectric properties of $Al_2O_3/SiO_2$-zinc borosilicate glass composites were investigated in the view of the application for LTCC. When the sintering was conducted at $900^{\circ}C$ $ZnAl_2O_4$ and $ZnB_2O_4$ compounds formed at the $Al_2O_3$-rich and the $SiO_2$-rich compositions, respectively. The reaction between ZBS glass and $Al_2O_3/SiO_2$ caused the formation of these compounds. The $Al_2O_3/SiO_2$ ratio affected the dielectric properties. The excellent dielectric properties, i.e., Q$\times$f value= 40,000 GHz and ${\varepsilon}_r$=4.5, were obtained in the $Al_2O_3/SiO_2$-ZBS glass system and fabricated the LTCC substrate materials.

• Corrosion Science and Technology
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• v.9 no.5
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• pp.175-186
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• 2010

The auto industry is demanding more ductile high-strength steel grades to build lighter and stronger car bodies. The hot-dip galvanizing problems of these new steel grades are creating a demand for an improved method to control zinc wettability. The simplest way to improve zinc wettability on industrial hot-dip galvanizing lines is to increase the strip immersion temperature at zinc bath entry for enhancing the aluminothermic reaction. However, this practice increases the reactivity due to overheating the zinc in the snout which induces the formation of brittle Fe-Zn compounds at the strip/coating interface with the formation of higher amounts of dross in the zinc bath and snout contamination. Thus, this simple practice can only be utilized for short production periods of one to two hours without deteriorating coating quality. This problem has been solved by employing a technique that allows the use of a higher and attuned strip immersion temperature at zinc bath entry while still maintaining a constantly low zinc bath temperature. This has been proven to provide the solution for both the improved wettability and a significant reduction in the amounts of dross in the zinc bath.

• Journal of Pharmaceutical Investigation
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• v.12 no.1
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• pp.1-11
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• 1982

Silver sulfadiazine has been introduced to replace silver nitrate in the topical treatment of extensive burns and this drug exerts a prominent antibacterial action against Pseudomonas aeruginosa. The compound is painless upon application and insufficient sulfadiazine is absorbed to cause crystalluria. The primary purpose of the study was to clarify the antimicrobial action of zinc sulfadiazine ointment in comparison with silver sulfadiazine ointment as well as the pharmaceutical properties of the zinc sulfadiazine preparations. The results are summerized as followings: 1) The optimum ratio of two substrate compounds for the synthesis of zinc sulfadiazine are 2 moles of sulfadiazine and 1 mole of zinc sulfate at pH 6.0. 2) The stability of zinc sulfadiazine ointment preparation by using polyethylene glycol base, Beeler's base or polyoxyl 40 stearate base was more stable than that of silver sulfadiazine preparations. 3) The antimicrobial action of zinc sulfadiazine exhibits a stronger antimicrobial activity than that of sulfadiazine against Staphylococcus aureus but the opposite is true against Pseudomonas aeruginosa.

• Polymer(Korea)
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• v.37 no.3
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• pp.269-275
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• 2013

Thiuram (DPTT, TMTD), thiazole (MBT, MBTS), sulfenamide (CBS, NOBS), and zinc containing thiuram (dithiocarbamate) (ZDBC) type accelerators were added into silica and carbon black filled natural rubber (NR) compounds. Their effects on vulcanization time and rate were compared. The vulcanization rate of thiuram type accelerator added compounds showed the fastest rate, followed by thiazole and sulfenamide types. Silica filled natural rubber (NR) compounds showed a slower vulcanization time ($t_{s2}$, $t_{10}$, $t_{90}$) and lower cure rate index (CRI) than carbon black filled ones upon each accelerator.