• 제목/요약/키워드: acid sensitivity

검색결과 620건 처리시간 0.034초

Evaluation of Microbial Load in Oropharyngeal Mucosa from Tannery Workers

  • Castellanos-Arevalo, Diana C.;Castellanos-Arevalo, Andrea P.;Camarena-Pozos, David A.;Colli-Mull, Juan G.;Maldonado-Vega, Maria
    • Safety and Health at Work
    • /
    • 제6권1호
    • /
    • pp.62-70
    • /
    • 2015
  • Background: Animal skin provides an ideal medium for the propagation of microorganisms and it is used like raw material in the tannery and footware industry. The aim of this study was to evaluate and identify the microbial load in oropharyngeal mucosa of tannery employees. Methods: The health risk was estimated based on the identification of microorganisms found in the oropharyngeal mucosa samples. The study was conducted in a tanners group and a control group. Samples were taken from oropharyngeal mucosa and inoculated on plates with selective medium. In the samples, bacteria were identified by 16S ribosomal DNA analysis and the yeasts through a presumptive method. In addition, the sensitivity of these microorganisms to antibiotics/antifungals was evaluated. Results: The identified bacteria belonged to the families Enterobacteriaceae, Pseudomonadaceae, Neisseriaceae, Alcaligenaceae, Moraxellaceae, and Xanthomonadaceae, of which some species are considered as pathogenic or opportunistic microorganisms; these bacteria were not present in the control group. Forty-two percent of bacteria identified in the tanners group are correlated with respiratory diseases. Yeasts were also identified, including the following species: Candida glabrata, Candida tropicalis, Candida albicans, and Candida krusei. Regarding the sensitivity test of bacteria identified in the tanners group, 90% showed sensitivity to piperacillin/tazobactam, 87% showed sensitivity to ticarcillin/clavulanic acid, 74% showed sensitivity to ampicillin/sulbactam, and 58% showed sensitivity to amoxicillin/clavulanic acid. Conclusion: Several of the bacteria and yeast identified in the oropharyngeal mucosa of tanners have been correlated with infections in humans and have already been reported as airborne microorganisms in this working environment, representing a health risk for workers.

Synthesis and pH-Dependent Micellization of Sulfonamide-Modified Diblock Copolymer

  • Pal Ravindra R.;Kim Min Sang;Lee Doo Sung
    • Macromolecular Research
    • /
    • 제13권6호
    • /
    • pp.467-476
    • /
    • 2005
  • The main objective of this study was to develop and characterize pH-sensitive biodegradable polymeric materials. For pH-sensitivity, we employed three kinds of moieties: 2-amino-3-(lH-imidazol-4-yl)-propionic acid (H), N-[4-( 4,6-dimethyl-pyrimidin-2ylsulfamoyl)-phenyl]succinamic acid (SM), and 2- {3-[ 4-( 4,6-dimethyl-pyrim­idin- 2-ylsulfamoyl)-phenylcarbamoyl]-propionylamino} -3-(3 H - imidazol-4-yl)-propionic acid (SH). The pH -sensitive diblock copolymers were synthesized by ring opening polymerization and coupling reaction from poly(ethylene glycol) (MPEG), $\varepsilon$-caprolactone (CL), D,L-lactide (LA) and pH-sensitive moieties. The pH-sensitive SH molecule was synthesized in a two-step reaction. The first step involved the synthesis of SHM, a methyl ester derivative of SH, by coupling reaction of SM and L-histidine methyl ester dihydrochloride, whereas the second step involved the hydrolysis of the same. The synthesized SM, SHM and SH molecules were characterized by FTIR, $^{1}H$-NMR and $^{13}C$-NMR spectroscopy, whereas diblock copolymers and pH-sensitive diblock copolymer were characterized by $^{1}H$-NMR and GPC analysis. The critical micelle concentrations were determined at various pH conditions by fluorescence technique using pyrene as a probe. The micellization and demicellization studies of pH-sensitive diblock copolymers were also done at different pH conditions. The pH-sensitivity was further established by acid-based titration and DLS analysis.

Leptin and uric acid as predictors of metabolic syndrome in jordanian adults

  • Obeidat, Ahmad A.;Ahmad, Mousa N.;Haddad, Fares H.;Azzeh, Firas S.
    • Nutrition Research and Practice
    • /
    • 제10권4호
    • /
    • pp.411-417
    • /
    • 2016
  • BACKGROUND/OBJECTIVES: Metabolic syndrome (MetS) is a set of interrelated metabolic risk factors that increase the risk of cardiovascular morbidity and mortality. Studies regarding the specificity and sensitivity of serum levels of leptin and uric acid as predictors of MetS are limited. The aim of this study was to evaluate the serum levels of leptin and uric acid in terms of their specificity and sensitivity as predictors of MetS in the studied Jordanian group. SUBJECTS/METHODS: In this cross sectional study, 630 adult subjects (308 men and 322 women) were recruited from the King Hussein Medical Center (Amman, Jordan). The diagnosis of MetS was made according to the 2005 International Diabetes Federation criteria. Receiver operating characteristic curves were used to determine the efficacy of serum levels of leptin and uric acid as predictors of MetS in the studied Jordanian group. RESULTS: Study results showed that for identification of subjects with MetS risk, area under the curve (AUC) for leptin was 0.721 and 0.683 in men and women, respectively. Serum uric acid levels in men showed no significant association with any MetS risk factors and no significant AUC, while uric acid AUC was 0.706 in women. CONCLUSION: Serum leptin levels can be useful biomarkers for evaluation of the risk of MetS independent of baseline obesity in both men and women. On the other hand, serum uric acid levels predicted the risk of MetS only in women.

Diagnostic Performance of 2018 KLCA-NCC Practice Guideline for Hepatocellular Carcinoma on Gadoxetic Acid-Enhanced MRI in Patients with Chronic Hepatitis B or Cirrhosis: Comparison with LI-RADS Version 2018

  • Sang Min Lee;Jeong Min Lee;Su Joa Ahn;Hyo-Jin Kang;Hyun Kyung Yang;Jeong Hee Yoon
    • Korean Journal of Radiology
    • /
    • 제22권7호
    • /
    • pp.1066-1076
    • /
    • 2021
  • Objective: To evaluate the performance of the 2018 Korean Liver Cancer Association-National Cancer Center (KLCA-NCC) Practice Guidelines (hereafter, PG) for the diagnosis of hepatocellular carcinoma (HCC) using gadoxetic acid-enhanced MRI, compared to the Liver Imaging-Reporting and Data System (LI-RADS) version 2018 (hereafter, v2018). Materials and Methods: From January 2013 to October 2015, treatment-naïve hepatic lesions (≥ 1 cm) on gadoxetic acid-enhanced MRI in consecutive patients with chronic hepatitis B or cirrhosis were retrospectively evaluated. For each lesion, three radiologists independently analyzed the imaging features and classified the lesions into categories according to the 2018 KLCA-NCC PG and LI-RADS v2018. The imaging features and categories were determined by consensus. Generalized estimating equation (GEE) models were used to compare the per-lesion diagnostic performance of the 2018 KLCA-NCC PG and LI-RADS v2018 using the consensus data. Results: In total, 422 lesions (234 HCCs, 45 non-HCC malignancies, and 143 benign lesions) from 387 patients (79% male; mean age, 59 years) were included. In all lesions, the definite HCC (2018 KLCA-NCC PG) had a higher sensitivity and lower specificity than LR-5 (LI-RADS v2018) (87.2% [204/234] vs. 80.8% [189/234], p < 0.001; 86.2% [162/188] vs. 91.0% [171/188], p = 0.002). However, in lesions of size ≥ 2 cm, the definite HCC had a higher sensitivity than the LR-5 (86.8% [164/189] vs. 82.0 (155/189), p = 0.002) without a reduction in the specificity (80.0% [48/60] vs. 83.3% [50/60], p = 0.15). In all lesions, the sensitivity and specificity of the definite/probable HCC (2018 KLCA-NCC PG) and LR-5/4 did not differ significantly (89.7% [210/234] vs. 91.5% [214/234], p = 0.204; 83.5% [157/188] vs. 79.3% [149/188], p = 0.071). Conclusion: For the diagnosis of HCC of size ≥ 2 cm, the definite HCC (2018 KLCA-NCC PG) had a higher sensitivity than LR-5, without a reduction in specificity. The definite/probable HCC (2018 KLCA-NCC PG) had a similar sensitivity and specificity to that those of the LR-5/4.

포지티브 포토레지스트의 감도 증진을 위한 산증식제로 1-Hydroxy-4-tosyloxy cyclohexane과 1,4-Ditosyloxy cyclohexane에 관한 연구 (1-Hydroxy-4-tosyloxy cyclohexane and 1,4-Ditosyloxy cyclohexane as Acid Amplifiers To Enhance the Photosensitivity of Positive-Working Photoresists)

  • 정연태;이은주;권경아
    • 한국인쇄학회지
    • /
    • 제20권1호
    • /
    • pp.91-101
    • /
    • 2002
  • An acid amplifier is defined as an acid-generating agent which is decomposed autocatalytically to produce new strongly acidic molecules in a non-liner manner, The addition of the acid amplifiers to conventional chemically amplified photoresists consisting of photoacid generators and acid-sensitive polymers result in the improvement of photosensitivity due to the amplified generation of catalytic acid molecules as a result of the decomposition of acid amplifiers. We synthesized and evaluated 1-hydroxy-4-tosyloxy cyclohexane(AA-1) and 1,4-ditosyloxy cyclohexane(Ah-2) as novel acid amplifiers. The acid amplifiers(AA-1, AA-2) showed reasonable thermal stability for resist processing temperature. As estimated by the sensitivity curve, tort-butyl methacrylate homopolymer(ptBMA) film doped with AA-1 or 2 exhibited much higher photosensitivity than ptBMA film without AA-1 or 2. And AA-1 showed higher effect than AA-2 on enhancing photosensitivity of ptBMA film.

  • PDF

Functional roles of glutamic acid E143 and E705 residues in the N-terminus and transmembrane domain 7 of Anoctamin 1 in calcium and noxious heat sensing

  • Choi, Jonghyun;Jang, Yongwoo;Kim, Haedong;Wee, Jungwon;Cho, Sinyoung;Son, Woo Sung;Kim, Sung Min;Yang, Young Duk
    • BMB Reports
    • /
    • 제51권5호
    • /
    • pp.236-241
    • /
    • 2018
  • Anoctamin 1 (ANO1) is an anion channel that is activated by changes in cytosolic $Ca^{2+}$ concentration and noxious heat. Although the critical roles of ANO1 have been elucidated in various cell types, the control of its gating mechanisms by $Ca^{2+}$ and heat remain more elusive. To investigate critical amino acid residues for modulation of $Ca^{2+}$ and heat sensing, we constructed a randomized mutant library for ANO1. Among 695 random mutants, reduced $Ca^{2+}$ sensitivity was observed in two mutants (mutant 84 and 87). Consequently, the E143A mutant showed reduced sensitivity to $Ca^{2+}$ but not to high temperatures, whereas the E705V mutant exhibited reduced sensitivity to both $Ca^{2+}$ and noxious heat. These results suggest that the glutamic acids (E) at 143 and 705 residues in ANO1 are critical for modulation of $Ca^{2+}$ and/or heat responses. Furthermore, these findings help to provide a better understanding of the $Ca^{2+}$-mediated activation and heat-sensing mechanism of ANO1.

Label-free and sensitive detection of purine catabolites in complex solutions by surface-enhanced raman spectroscopy

  • Davaa-Ochir, Batmend;Ansah, Iris Baffour;Park, Sung Gyu;Kim, Dong-Ho
    • 한국표면공학회지
    • /
    • 제55권6호
    • /
    • pp.342-352
    • /
    • 2022
  • Purine catabolite screening enables reliable diagnosis of certain diseases. In this regard, the development of a facile detection strategy with high sensitivity and selectivity is demanded for point-of-care applications. In this work, the simultaneous detection of uric acid (UA), xanthine (XA), and hypoxanthine (HX) was carried out as model purine catabolites by surface-enhanced Raman Spectroscopy (SERS). The detection assay was conducted by employing high-aspect ratio Au nanopillar substrates coupled with in-situ Au electrodeposition on the substrates. The additional modification of the Au nanopillar substrates via electrodeposition was found to be an effective method to encapsulate molecules in solution into nanogaps of growing Au films that increase metal-molecule contact and improve substrate's sensitivity and selectivity. In complex solutions, the approach facilitated ternary identification of UA, XA, and HX down to concentration limits of 4.33 𝜇M, 0.71 𝜇M, and 0.22 𝜇M, respectively, which are comparable to their existing levels in normal human physiology. These results demonstrate that the proposed platform is reliable for practical point-of-care analysis of biofluids where solution matrix effects greatly reduce selectivity and sensitivity for rapid on-site disease diagnosis.

급성 신우신염 환아들의 나이에 따른 Dimercaptosuccinic Acid Renal Scan 민감도 (Sensitivity of Dimercaptosuccinic Acid(DMSA) Renal Scan in Children with Acute Pyelonephritis)

  • 장경아;양정아;하태선;박혜원;이준호
    • Childhood Kidney Diseases
    • /
    • 제7권1호
    • /
    • pp.38-43
    • /
    • 2003
  • 목적 : 소아에서는 임상증상만으로 요로감염의 정확한 진단이 어려우므로 DMSA renal scan은 급성 신우신염의 조기 진단과 감별에 중요한 방법이다. 급성 신우신염 환자에서 환자 연령에 따른 DMSA renal scan의 양성률, 신장초음파의 이상여부, 방광요관역류 동반율을 비교해 보고자 하였다. 또 DMSA renal scan과 신장초음파 결과 및 DMSA renal scan과 방광요관역류와의 상관관계를 알아보았다. 방법 : 2001년 3월부터 2002년 9월까지 급성신우신염으로 진단된 67명의 환아를 대상으로 나이에 따라 2세 이하의 소아 57명을 그룹 I으로, 2세 이상의 소아 10명을 그룹 II로 나누었다. 이 환아를 대상으로 DMSA renal scan, VCUG, 신장초음파의 결과를 이용한 후향적 연구를 실시하였다. 결과 : 급성 신우신염 환아에서 DMSA renal scan의 양성률은 나이에 따라서 차이가 없었다. DMSA renal scan과 방광요관역류 등급정도와는 통계학적 의미가 있었으나, 나이에 따른 방광 요관역류와는 통계학적 의미는 없었다. DMSA renal scan과 신장초음파 이상여부와는 의미가 없었다. 나이에 따른 신장초음파 이상여부와도 통계학적 의미는 없었다. 결론 : 현재로서는 DMSA renal scan은 급성 신우신염이 의심되거나, 세균뇨가 있는 환자에게서 감별 진단시 힘들이지 않고, 비교적 경제적 부담이 적은 중요한 검사 방법이다.

  • PDF

휘발성유기화합물가스에 대한 폴리아닐린 센서의 감도 향상 (Sensitivity Enhancement of Polyaniline Sensor to Volatile Organic Compounds)

  • 유준부;유비;임정옥;변형기;허증수
    • 한국재료학회지
    • /
    • 제17권8호
    • /
    • pp.433-436
    • /
    • 2007
  • Nano-structured polyaniline have been synthesized by interfacial polymerization method at room temperature. An aqueous solution of aniline in chloroform and another solution of ammonium peroxydisulfate in doping acid were prepared at different times terminated with methanol at room temperature. SEM, UV-vis were used to characterize the polyaniline with regard to their morphology and structure. The diameter and length of polyaniline can be controlled by the reaction time. Nano-structured polyaniline were found to have superior sensitivity for volatile organic compounds(VOCs). As the reaction time to increase from 30minute to 2hours the sensitivity were decreased to VOCs vapors. The sensitivity of Nano-structured polyaniline sensor appeared to VOCs better than the sensitivity of chemical synthesis sensors. The sensitivity of Nano-structured polyaniline sensor improved benzene vapors.