An Autonomous Instrument for Potentiometric Stripping Analysis

Davey, D.E.,Chow, C.W.K. 경북대학교 센서기술연구소 1994 센서技術學術大會論文集 Vol.5 No.1

In this paper, a flexible, low-cost potentiometric stripping analysis (PSA) system using the Philips BC bus system and an IBM compatible PC is described. PSA requires a controlled potentiostat which can be turned on and off reproducibly, and excellent mV resolution. The PSA system, controlled by an expert system designed and constructed by us, has initially been applied to the analysis of cadmium, lead and copper. The expert system, not only provides direct equipment control but also interprets the results based on its knowledge base and provides adjustments of the experimental parameters to optimize the analysis. The selected expert system builder, Crystal, is an extremely simple programming environment, the instruction being almost in the form of standard English. Two digital signal processing methods, polynomial smoothing and rectangular low pass filtering are available in our software. Each has yielded signal-to-noise (S/N) improvement over the original data and a linear peak area - concentration relationship was retained in all cases. After digital signal processing, peak height as the measuring parameter also gave a good linear relationship to concentration. The filtering approach which allows optimum filtering and best peak resolution was readily established. The resolution of overlapping potential peaks (copper and bismuth were selected as a more difficult example) was best improved using the rectangular low pass filtering method, although the two mentioned approaches were both acceptable.

외래에서 초기 HIV감염자 인터루킨 피하주사 용량에 따른 효과

RT Davey,DG Jr. Chaitt,JM Albert 대한에이즈예방협회 1999 레드리본 Vol.28 No.-

Unreliable Narratives: Historical and Archaeological Approaches to Early Silla

( Jack Davey ) 서울대학교 규장각한국학연구원 2016 Seoul journal of Korean studies Vol.29 No.1

This paper surfaces the major contradictions between the “Account of the Han” in the third-century Sanguozhi 三國志 (Records of the Three Kingdoms) and the twelfth-century records of early Silla in the Samguk sagi 三國史記 (History of the Three Kingdoms) with regards to the formation of the Silla kingdom in southeastern Korea during the third and fourth centuries. Archaeological material, specifically grave goods and cemeteries, is then employed to assess the conflicting historical accounts. Analysis of burial customs and tomb styles does suggest that there was a high degree of cultural cohesion evident in the region, which broadly agrees with both the above textual accounts. Nevertheless, the inconsistent adoption of grave construction techniques, differing levels of commitment to a uniform ritual practice between sites, and variable grave good displays attest to a high degree of diversity and the lack of an overarching governmental authority in southeastern Korea. The picture that emerges from the ritual evidence is one of many independent groups with a fundamentally similar cultural grammar. While the archaeology does concur with historians that favor the “Account of the Han” and the Sanguozhi, there are still problems with both texts’ assertions of regional political structures and centralization. And while the two texts may be fundamentally incompatible, there is still potential value in the Samguk sagi’s accounts of Silla’s incipient warfare with neighboring groups.

SARS-CoV-2 Variants of Concern

최준용,Davey M. Smith 연세대학교의과대학 2021 Yonsei medical journal Vol.62 No.11

Since the COVID-19 pandemic first began in December 2019, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has continuously evolved with many variants emerging across the world. These variants are categorized as the variant of interest (VOI), variant of concern (VOC), and variant under monitoring (VUM). As of September 15, 2021, there are four SARS-CoV-2 lineages designated as the VOC (alpha, beta, gamma, and delta variants). VOCs have increased transmissibility compared to the original virus, and have the potential for increasing disease severity. In addition, VOCs exhibit decreased susceptibility to vaccineinduced and infection-induced immune responses, and thus possess the ability to reinfect previously infected and recovered individuals. Given their ability to evade immune responses, VOC are less susceptible to monoclonal antibody treatments. VOCs can also impact the effectiveness of mRNA and adenovirus vector vaccines, although the currently authorized COVID-19 vaccines are still effective in preventing infection and severe disease. Current measures to reduce transmission as well as efforts to monitor andunderstand the impact of variants should be continued. Here, we review the molecular features, epidemiology, impact on transmissibility, disease severity, and vaccine effectiveness of VOCs.

Alcohol Consumption, Aldehyde Dehydrogenase 2 Gene Polymorphisms, and Cardiovascular Health in Korea

신민정,조윤수,George Davey Smith 연세대학교의과대학 2017 Yonsei medical journal Vol.58 No.4

Alcohol consumption is a serious health issue in Korea in terms of the amount consumed and the behavior related to its consumption. Aldehyde dehydrogenase 2 (ALDH2) is a key enzyme in alcohol metabolism that degrades acetaldehyde to nontoxic acetic acid. The enzyme is coded by the ALDH2 gene, which is commonly polymorphic in East Asian populations. A point mutationin the ALDH2 gene (the rs671 allele) yields an inactive form of ALDH2 that causes acetaldehyde accumulation in the body after alcohol consumption, thereby inhibiting normal alcohol metabolism. Individuals who are homozygous for polymorphism in ALDH2 tend to refrain from drinking alcohol, decreasing their chances of developing alcoholism and exposure to the associatedrisks. Mendelian randomization (MR) studies have demonstrated that alcohol consumption predicted by ALDH2 genotype is causally related to cardiovascular risks. Moreover, recent MR studies suggest that the ALDH2 variant has mechanistic effects on some disease outcomes or mortality through increased blood levels of acetaldehyde, showing differences therein between heterozygotes(ALDH2*2*2) and homozygotes (ALDH2*1*2) in those who consume alcohol. Accordingly, consideration of ALDH2 genotype in alcohol prevention programs is warranted. In conclusion, strategies that incorporate genetic information and providean evidential basis from which to help people make informed decisions on alcohol consumption are urgently required.

Pathology

Henry, John Bernard,Davey, Frederick R. MediMedia Korea 1986 JAMA-Korea Vol.1 No.13

Green marketing of apparel: consumers’ price sensitivity to environmental marketing claims

Celia Stall-Meadows,Anne Davey 한국마케팅과학회 2013 Journal of Global Fashion Marketing Vol.4 No.1

Green or environmentalmarketing claims have increased in recent years because of potentiallyhigher profits for companies. The aimof this study was to identify the environmentalmarketing claims forwhich consumers arewilling to pay higher prices. The specific claimsinvestigated in this study were: using organic fibers or recycled textile fibers; sustainablemanufacturing; companies donating to green organizations; and using fair trade and laborpractices. A quantitative survey of college students in the Midwestern US revealed that acompany’s environmental marketing claims – particularly with regard to manufacturingwith organic fibers and donating to green organizations – resulted in decreased consumerprice sensitivity. The theory of reasoned action served as the framework for the study. Implications, limitations, and suggestions for further research are presented.

SARS-CoV-2 Omicron Variant of Concern: Everything You Wanted to Know about Omicron but Were Afraid to Ask

Dong Hoon Shin,Davey M. Smith,최준용 연세대학교의과대학 2022 Yonsei medical journal Vol.63 No.11

As soon as the first case of the omicron variant of severe acute respiratory syndrome coronavirus 2 was reported in November 2021, it quickly spread worldwide with the emergence of several subvariants. Compared to previous variants, omicron was heavily mu tated, especially for those in the Spike (S) protein and its receptor-binding domain. These mutations allowed the viruses to evade immune responses (i.e., previous infections and vaccine-elicited) and increase in transmissibility. Although vaccine effectiveness is decreased for omicron, boosters remain effective for protecting against severe diseases. Also, bivalent vaccines have been devel oped to increase vaccine effectiveness. Interestingly, although omicron is highly infectious, it has less morbidity and mortality compared to previously identified variants, such as delta. Additionally, the mutations that allow the virus to evade immune re sponses also allow it to evade many of the monoclonal antibodies developed at the beginning of the pandemic for treatment. Here, we reviewed the omicron variant’s epidemiology, genetics, transmissibility, disease severity, and responsiveness to vaccine and treatments.

Flow Injection Stripping Potentiometry with Periodic Alternation of Flow Direction

Chow, Christoper W.K.,Kolev, Spas D.,Davey, David E. 경북대학교 센서기술연구소 1994 센서技術學術大會論文集 Vol.5 No.1

A fully computerized flow injection (FI) manifold with a peristaltic pump allowing periodic alternation of the flow direction and incorporating a detector system capable of performing potentiometric stripping analysis (PSA) is outlined. The proposed measuring technique combines the attractive features of both traditional flow injection analysis (FIA) and batch PSA and at the same time overcomes some of the most serious drawbacks of the latter resulting from the fact that potentiostatic deposition and chemical stripping occur in the same solution. An experimental study of the influence of the main parameters of the flow system on its behaviour was performed using Cu(II) solutions in the parts per billion concentration range as samples. The potentiostatic deposition was carried out on a precoated Hg glassy carbon electrode while Hg(II) ions were utilized as oxidant in the chemical stripping step. The magnitude of the analytical signal is independent of the electrode area which allows miniaturization of the equipment. The results obtained suggest that the proposed technique could be implemented in compact, inexpensive and fully automated flow-through systems for quantitative determination of low concentration metals ions in various samples (e.g., heavy metals in environmental, food and pharmaceutical samples).

Assessing clinical impact of HIV infection in children by knowledge driven data mining

Kanarkard, W.,Patumwan, P.,Adams, R.,Davey, N. 대한전자공학회 2007 ITC-CSCC :International Technical Conference on Ci Vol.2007 No.7

This paper proposes the development of a computerised decision aid using knowledge driven data mining that provides the assessment of clinical care during pregnancy and the impact of HIV infection in her children who has a viral transmission from mother. HIV infection and AIDS have severely disrupted child mortality and child health services in many developing countries including Thailand. This study validated the predictive power of data mining algorithms by comparing the performance of two decision tree algorithms, C4.5 and ID3 using the test set of 1,773 pregnant women and the training set of 2,548 pregnant women. Overall performances of these two algorithms were 99.73% of accuracy. In addition, the C4.5 algorithm performed better than the ID3. The decision tree algorithms not only identified but also provided decision rules for identifying critical factors in clinical care that could prevent the HIV transmission from mother to child.