• The Korean Journal of Pain
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• 제30권4호
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• pp.265-271
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• 2017

Background: Health care services effort to provide alternative cardiac rehabilitation (CR) models to serve patients according to their preferences and needs. So, the present study aimed to assess and compare the effects of hospital-based and hybrid CR programs on chest pain intensity and discomfort in cardiac surgery patients. Methods: In this prospective study, 110 cardiac surgery patients were invited to the CR department of a hospital in the western part of Iran between March and July 2016. Patients were divided into two groups: hospital-based and hybrid CR. The hospital-based program included 26 sessions, and the hybrid program included 10 training sessions and exercise. The Brief Pain Inventory and Pain Discomfort Scale were used as research instrument, and data were analyzed using the paired t-test and ANCOVA. Results: The results indicated that both hospital-based and hybrid CR are effective in reducing the chest pain intensity and discomfort of cardiac surgery patients (P < 0.05). In addition, the comparison of scores before and after treatment using ANCOVA shows that no significant differences were observed between the two programs (P > 0.05). Conclusions: Traditional hospital-based CR delivery is still the first choice for treatment in developing countries. However, hybrid CR is as effective as a hospital-based program in reducing pain components and it includes only 38% of the total cost in comparison to hospital-based delivery. So, we recommend using hybrid CR according with the recommendations of American Heart Association about using CR for the management of angina symptoms.

• Biomolecules & Therapeutics
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• 제9권4호
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• pp.277-281
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• 2001

Chromium is an essential nutrient and participates in glucose and lipid metabolism in human beings and animals. The present study was conducted to assess the effects of chromium picolinate (Cr-pic) on glucose tolerance and insulin sensitivity in type I and ll diabetic rats. The experimental groups were type I diabetic (streptozotocin-induced: 40 mg/kg, i.p.) and type II diabetic (Goto-Kakizaki rats) models. Each group was subdivided into control. low-dose and high-dose of Cr-pic treated groups. The Cr-pic was orally administered with Cr-pic (100 mg/kg for low dose group and 200 mg/kg for high dose group) for 4 weeks. And then we performed intraperitoneal glucose tolerance test (IPGTT) and insulin sensitivity test (ITT). The glucose tolerance test was carried out by inection of glucose (2 g/kg, i.p.). The peripheral insulin sensitivity test was con- ducted by injection of insulin (5 units/kg, s.c.) and glucose. We performed determining of blood glucose concentration at 0, 10, 30, 60, 90, and 120 min using automated glucose analyzer. The plasma insulin concentration was determined by rat insulin EIA kit. Administration of Cr-pic improved weight gain in all group s with higher significant in the low-dose group. There was no significance between the control and the Cr-pic treated groups in the area under the blood glucose curve and serum insulin concentration plots of IPGTT and peripheral ITT in type I diabetic rats. But Cr-pic treated groups showed significantly lower levels of the area under the blood glucose currie during IPGTT and ITT and the high-dose group showed less effects compared with the low-dose group in the type II diabetic rats. The plasma insulin concentration of both diabetic groups was not influenced by Cr-pic supplementation. We can conclude that chromium picolinate may improve the endogenous and exogenous insulin action and peripheral insulin sensitivity in type II diabetic rats.

• Bulletin of the Korean Chemical Society
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• 제27권5호
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• pp.694-698
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• 2006

A method has been described for the chemical speciation, preconcentration and determination of Cr(III) and Cr(VI) species in filtered tannery waste waters by flame atomic absorption spectrometry using ion-exchange resins. Amberlite IR-120($H^+$) strongly acidic cation exchanger and Amberlite IRA-410($CI ^-$) strongly basic anion exchanger resins were used for the separation and preconcentration of Cr(III) and Cr(VI) species, respectively. Optimum condition for preconcentration and speciation was obtained by testing pH of sample and eluent, flow rates of sample and eluent, amount of resins, volume of sample and eluents, and effect of foreign ions. The recommended method has been successfully applied for the preconcentration and determination of chromium species in the dissolved phase of waste water samples collected from a tannery waste water treatment plant in Kayseri, Turkey. The detection limits achieved were 0.73 $\mu$g/L for Cr(III) and 0.81 $\mu$g/L for Cr(VI). Recovery studies showed 99% for Cr(III) and 98% for Cr(VI), for samples spiked with single species.

• 한국수산과학회지
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• 제38권3호
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• pp.153-157
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• 2005

The biosorption of Pb and Cr by Sargassum thunbergii was investigated in a batch conditions. The Pb and Cr uptake capacity of Sargassum thunbergii was 232.5 mg Pb/g biomass and 91.6 mg Cr/g biomass, respectively. An adsorption equilibria was reached within about 0.5 hr for both the Pb and the Cr. The adsorption parameters for both the Pb and the Cr were determined according to the Langmuir and Freundlich model. With increasing pH values, more negative sites are becoming available for the adsorption of Pb and Cr. The selectivity of mixture solution showed an uptake order of Pb>Cu>Cr>Cd. Pb and Cr adsorbed by S. thunbergii could be recovered ken 0.1 M HCl, 0.1 M $HNO_3$ and 0.1M EDTA by a desorption process, and the efficiency of Pb desorption was above $95.8\%$, whereas the efficiency of the Cr desorption was below $50.7\%$.

• Journal of Microbiology
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• 제35권1호
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• pp.25-29
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• 1997

Microbial reduction of hexavalent (VI) to trivalent (III) chromium decreases its toxicity by two orders of magnitude. In order to investigate the nature of Cr-reduction, Cr-resistant Pseudomonas aeruginosa HP014 was isolated and tested for its reduction capability. At the concentration of 0.5 mM Cr(VI), cell growth was not inhibited by the presence of Cr(VI) in a liquid medium, and Cr(VI) reduction was accompanied by ell growth. When cell-free extract was tested, the reduction of Cr(VI) showed a saturation kinetics with the maximum specific activity of 0.33 .mu.mol min$\^$-1/ mg$\^$-1/ cell protein, and an apparent K. of 1.73 mM Cr(VI). The activity required either NADH or NADPH as an electron donor. However, NADPH gave 50% as mush activity as sequently the supernatant and pelleted membrane fractions were tested for Cr(VI) reduction activity. The supernatant of the centrifugation showed almost the same Cr(VI) reduction activity as compared with that of the cell-free extract, indicating that the Cr(VI)-reducing activity of P. aeruginosa HP-14 is due to soluble enzyme. Moreover, the activity appeared to be the highest among the known activities, suggesting that the strain might be useful for remediation of Cr(VI)-contaminated sites.

• Tribology and Lubricants
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• 제19권4호
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• pp.211-216
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• 2003

This paper was studied on the corrosion and corrosion-wear behavior of chromium (Cr) plating in the acidic environments. In the various pH of acidic solutions, the electrochemical polarization test and wear-corrosion test of Cr plating were carried out. And thus potential, corrosion current density and corrosion-wear loss behaviour of Cr plating are investigated.

• 한국산학기술학회논문지
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• 제18권9호
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• pp.244-250
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• 2017

보철물의 완성도를 평가할 수 있는 요소는 여러 가지가 있으나, 그 중 가장 중요한 하나는 보철물의 적합도이다. 합금은 기계적, 물리적 성질 그리고 연마성 개선을 위해 연화열처리나 경화열처리 과정을 거치는데, 이때의 열처리 방법이 Ni-Cr 합금 core의 변연 및 내면 간격에 어떠한 영향을 미치는지 알아보고자 한다. 실험을 위해 하악 좌측 대구치가 지대치인 석고 모형 30개를 제작하고 dipping법을 이용하여, 3 group(A, B, C)으로 나누어 group당 10개, 총 30개의 Ni-Cr 합금 core를 제작 하였다. 이들을 열처리를 하지 않은 것과 연화, 경화 열처리 방법으로 열처리함에 따라 적합도를 silicone replica technique을 이용하여 측정하였다. 세 집단 간의 평균값에 유의한 차이가 있는지 알아보기 해 독립표본 t-검정으로 분석하였다(${\alpha}=0.05$). 실험 결과 변연 부위(1, 6)에서는 통계적으로 유의한 차이를 보였으나(p<0.05), 나머지 내면 부위(2, 3, 4, 5)에서는 유의한 차이를 보이지 않았다(p>0.05). 이러한 결과로 미루어 볼 때 Ni-Cr 합금은 열처리를 하지 않는 것이 적합도 측면에서 나을 것으로 사료된다. 이에 추가적인 임상적용 연구를 통해 더욱 심도 있는 평가되어야 할 것으로 판단된다.

• 대한치과보철학회지
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• 제41권1호
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• pp.1-19
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• 2003

The surface of metals should be as smooth as possible for optimum comfort, oral hygiene, low plaque retention, and resistance to corrosion. In this study five specimens of each precious metal(type III gold alloy, ceramic gold alloy, and Ag-Pd alloy) were divided into five groups according to finishing and polishing procedures : group 1(sandblaster), group 2(group 1+stone), group 3(group 2+brown rubber), group 4(group 3+green rubber), and group 5(group 4+rouge). Six specimens of each non-precious metal(Co-Cr alloy, Ni-Cr alloy, and Co-Cr-Ti alloy) were divided into six groups: group 1(sandblaster), group 2(group 1+hard stone), group 3(group 2+electrolytic polisher), group 4(group 3+brown hard rubber point), group 5(group 4+green hard rubber point), and group 6(group 5+rouge). Considering factors affecting the rate of abrasion, the same dentist applied each finishing and polishing procedure. In addition, the surface roughness of enamel, resin, and porcelain was evaluated. The effect of finishing and polishing procedures on surface roughness of precious and non-precious metals, enamel, resin, and porcelain was evaluated by means of Atomic Force Microscope(AutoProbe CP. Park Scientific Instruments, U.S.A.) that can image the three dimensional surface profile and measure average surface roughness values of each sample at the same time. The obtained results were as follows : 1. According to finishing and polishing procedures, the surface roughness of type III gold alloy, ceramic gold alloy, and Ag-Pd alloy was decreased in the order of group 1, 2, 3, 4, and 5 (P<0.01). 2. According to finishing and polishing procedures. the surface roughness of Co-Cr alloy, Ni-Cr alloy, and Co-Cr-Ti alloy was decreased in the order of group 1, 2, 3, 4, 5, and 6 (p<0.01). 3. There was not statistically significant difference in the surface roughness among three metals of precious metals in group 1 but was significant difference in group 2, 3, 4, and 5 (P<0.05). 4. There was not statistically significant difference in the surface roughness among three metals of non-precious metals in all groups. 5. When the surface roughness of the smoothest surface of each metal, enamel. porcelain, and resin was compared, porcelain was the smoothest and the surface roughness was decreased in the order of Ni-Cr alloy. Co-Cr alloy. Co-Cr-Ti alloy, resin. Ag-Pd alloy, ceramic gold alloy type III gold alloy, and enamel (P<0.01). The results of this study indicate that the finishing and polishing procedures should be carried out in a logical, systematic sequence of steps and the harder non-precious metals may be less resistance to abrasion than are the softer precious metals.

• 한국환경보건학회지
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• 제27권3호
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• pp.107-112
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• 2001

This work reports the application of a hollow fiber module(HFM) for Cr(VI) extraction from heavy metal salts mixed solution by using microporous hydrophobic hollow fiber module. In HFM configuration, the organic extraction used for the extraction of Cr(VI) was di-(2-ethyl hexyl) phosphoric acid(D2EHPA) diluted with n-heptane. The study of HFM includes the influence of hydrodynamic and chemical condition, i.e., the flow rate of feed solution, the time of reactive extraction, the concentration of feed solution, and the pH of aqueous phase solutions. Several experiments with synthetic solution of different mixed components system of Cr(VI) solutions established optimum condition to achieve a clean separation of Cr(VI). It was possible to separate Cr(VI) in the presence of metal salts mixed solution, such as Zn(II), Ni(II), Cu(II), and Cd(II) using the HFM technique.

• Journal of Microbiology and Biotechnology
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• 제22권12호
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• pp.1767-1775
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• 2012

The Cr(VI) removal capability of Acinetobacter junii VITSUKMW2 isolated from the Sukinda chromite mine site was evaluated and enhanced using statistical design techniques. The removal capacity was evaluated at different pH values (5-11) and temperatures ($30-40^{\circ}C$) and with various carbon and nitrogen sources. Plackett-Burman design was used to select the operational parameters for bioremediation of Cr(VI). Three parameters (molasses, yeast extract, and Cr(VI) concentration) were chosen for further optimization using central composite design. The optimal combination of parameters was found to be 14.85 g/l molasses, 4.72 g/l yeast extract, and 54 mg/l initial Cr(VI), with 99.95% removal of Cr(VI) in 12 h. A. junii VITSUKMW2 was shown to have significant potential for removal of Cr(VI).