1.Statistical notes for clinical researchers: assessing normal distribution (2) using skewness and kurtosis.
Restorative Dentistry & Endodontics 2013;38(1):52-54
No abstract available.
Normal Distribution*
2.Statistical notes for clinical researchers: assessing normal distribution (1).
Restorative Dentistry & Endodontics 2012;37(4):245-248
No abstract available.
Normal Distribution*
3.Detection of Virulent Gene Distribution of Diarrheagenic Escherichia Coli (DEC)
Journal of Medical Research 2008;0(1):50-55
Introduction: There are 5 identified DEC including EAEC, EHEC, EIEC, EPEC and ETEe. Virulent genes (for adherrnee, toxin, antibiotic resistance ...) play important roles in pathogenesis of DEe. Detection of DEC is very important in diagnosis, epidemiology survey and vaccine development. \r\n', u'Objectives: Detection of virulent gene distribution of DEC and non - DEe.\r\n', u'Object and methods: 161 strains of DEC (EAEC, EIEC, EPEC, TEC) and 100 strains of non - DEC were subjected to this study. PCR with specific primers were used to test these genes. \r\n', u'Results: EAEC that accounted for 50% of DEC, was identified and isolated. Aap gene was the highest prevalence in EAEC (96.5%), followed by aggR (79.1 %) and astA (60.5%). 37.2% of the strains harbor all three genes. None of strains had PCR results negative for these 3 genes. ETEC, EPEC and EIEC had aap, and astA gene at the prevalence from 7% to 72.7%. The highest prevalence of aap was seen in EIEC 72.7%), aggR in EIEC (45.5%), and astA in ETEC (50%). 14% of non - DEC had aggR and more than 30% of E. coli had aap and astA gene. \r\n', u'Conclusion: EAEC is prevalent at 50% among Diarreagenic E. coli. Aap is the most prevalent and the most commonly seen among EAEC isolates. The other three genes are at different prevalence. The findings contribute towards the vaccine development against diarrhea caused by E. coli. \r\n', u'
Distribution
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Virulent gene
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E.coli
4.Review of drug supply during past ten years of renovation and proposed problem for this in the coming years
Pharmaceutical Journal 1999;274(2):7-9
The Famacy Branch has quietly been developing, met the most of needs of drug and medical equipment and overcome the lack of them in many past years. The average expense for drug per capita is 3,2USD/year in 1994, is 6 fold higher than this during 1986-1990. The expansion of drug services delivered drugs to village, grassroots, remote and mountain areas.
Pharmaceutical Preparations
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supply & distribution
5.Situation of drug buying of people in some provinces of the North of Vietnam
Pharmaceutical Journal 2001;298(2):6-8
An investigation of the drug buying situation of people in some provinces of the North of Vietnam has shown that there was a trend of use of multi drugs for a duration of treatment. The rate of drug buying according to the prescription was low of which the rate of resuse of prescription was high; 76% of users bought drugs as instruction of drug seller. The benefit impacted strongly on the behaviour and attitude of physicians, drug seller leading to prescription for many drugs, drug with expensive price. The pharmacy authorities should have solutions and communicate and educate the safe and rational use of drug use in the community.
Pharmaceutical Preparations
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supply & distribution
6.Ocular Thermometer Utilizing Thermistor.
Jae Myung KIM ; Sang Min KIM ; Jae In HA ; Won Shik YOUN
Journal of the Korean Ophthalmological Society 1965;6(2):7-9
A sensitive thermometer utilizing thermistor as a sensing element has been constructed in order to measure the temperatures in various ocular tissues. The Wheatstone bridge was used to detect the changes in thermistor resistance. The out-put of the bridge was fed into a single-stage differential DC amplifier and read by an micro-ammeter. There was a linear relationship between temperature and meter scale. The thermistor was inserted into the inferior conjunctival sacs of 158 healthy normal human eyes. The average temperature was found to be 35.14 +/- 1.08 (in C). No difference due to sex and age distribution was found to exists. Preliminary temperature measurement has been done on rabbits. Their results are shown graphically in Fig. 3.
Age Distribution
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Humans
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Rabbits
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Thermometers*
7.Blood Lead Levels of Children in Ulsan Industrial Area.
Cheol In YOO ; Ji Ho LEE ; Choong Ryeol LEE ; Sung Ryul KIM ; Seon Ho LEE
Korean Journal of Preventive Medicine 1998;31(2):240-248
We conducted this study, to obtain basic data of lead concentrations in children of Ulsan industrial area and to evaluate the difference in blood lead levels between industrial area and suburban area. The study subjects were composed of 348 school children residing in industrial area and 100 school children of suburban area. There is no difference in age and sex distribution of study participants between industrial and suburban area. The obtained results were as follows: l. The geometric means of blood lead levels of study participants were 4.90 ng/dl, which is lower than current acceptable value 10 ng/dl. 2. The children residing in industrial area had the higher blood lead levels(5.26 ng/dl) than suburban children(3.81 ng/dl) with statistical significance(P<0.001).
Child*
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Humans
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Sex Distribution
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Ulsan*
8.Clinical Study on Urethral Caruncle.
Korean Journal of Urology 1976;17(4):277-282
Clinical observation was done on the 23 cases of urethral caruncle which were confirmed pathologically during the period from January 1965 to August 1976 and the following results were obtained. 1. Age distribution was between 8 and 81 years, showing the highest incidence in 31 to 60 years (18/23, 78.3%) and the mean age was 45.2 years. 2. Among them, 16 cases were telangiectatic type (16/23, 69. 6%), 4 were papillomatous type (4/23, 17.4%) and 3 were granulomatous type (3/23, 13.0%). 3. Most common location was posterior lip of the urethral meatus (20/23, 87.1%) but anterior lip 1 and combined 2 respectively. 4. Excision and electrofulguration were performed in all cases and one case of recurrence was noticed.
Age Distribution
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Incidence
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Lip
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Recurrence
9.More about the basic assumptions of t-test: normality and sample size
Korean Journal of Anesthesiology 2019;72(4):331-335
Most parametric tests start with the basic assumption on the distribution of populations. The conditions required to conduct the t-test include the measured values in ratio scale or interval scale, simple random extraction, normal distribution of data, appropriate sample size, and homogeneity of variance. The normality test is a kind of hypothesis test which has Type I and II errors, similar to the other hypothesis tests. It means that the sample size must influence the power of the normality test and its reliability. It is hard to find an established sample size for satisfying the power of the normality test. In the current article, the relationships between normality, power, and sample size were discussed. As the sample size decreased in the normality test, sufficient power was not guaranteed even with the same significance level. In the independent t-test, the change in power according to sample size and sample size ratio between groups was observed. When the sample size of one group was fixed and that of another group increased, power increased to some extent. However, it was not more efficient than increasing the sample sizes of both groups equally. To ensure the power in the normality test, sufficient sample size is required. The power is maximized when the sample size ratio between two groups is 1 : 1.
Biostatistics
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Normal Distribution
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Sample Size
10.Central limit theorem: the cornerstone of modern statistics.
Korean Journal of Anesthesiology 2017;70(2):144-156
According to the central limit theorem, the means of a random sample of size, n, from a population with mean, µ, and variance, σ², distribute normally with mean, µ, and variance, σ²/n. Using the central limit theorem, a variety of parametric tests have been developed under assumptions about the parameters that determine the population probability distribution. Compared to non-parametric tests, which do not require any assumptions about the population probability distribution, parametric tests produce more accurate and precise estimates with higher statistical powers. However, many medical researchers use parametric tests to present their data without knowledge of the contribution of the central limit theorem to the development of such tests. Thus, this review presents the basic concepts of the central limit theorem and its role in binomial distributions and the Student's t-test, and provides an example of the sampling distributions of small populations. A proof of the central limit theorem is also described with the mathematical concepts required for its near-complete understanding.
Mathematical Concepts
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Normal Distribution
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Statistical Distributions