• Title/Summary/Keyword: small sample size

Search Result 737, Processing Time 0.028 seconds

Effects of water temperature for oral rinse and the use of toothpastes and tongue cleaners on halitosis (잇솔질 시 양칫물 온도, 치약 사용, 혀클리너 사용에 따른 구취의 영향)

  • Hwang, Soo-Jeong;Jung, Yoon-Zy;Lee, Soo-Kyoung;Lee, Ji-Eun;Lee, Hee-So;Jeon, Hee-Ju;Kim, Do-Kyeong
    • Journal of Korean Academy of Dental Administration
    • /
    • v.7 no.1
    • /
    • pp.44-49
    • /
    • 2019
  • Halitosis is primarily caused by oral conditions. In particular, volatile sulfur compounds (VSCs) are mainly responsible for intra-oral halitosis. They are closely associated with the water temperature. In this study, we investigated the association between halitosis and water temperature for oral rinse (10℃, 30℃, and 45℃) using the BB checker and oral chroma. The application of BB checker on an empty stomach revealed that halitosis decreased with the use of tongue cleaners (p=0.001) and toothpastes (p=0.002). Furthermore, halitosis decreased after drinking milk (VSCs-induced food intake) (p=0.000). There were no significant differences in the results of oral chroma. Finally, we measured halitosis on an empty stomach and after drinking milk. The BB checker showed increased halitosis after drinking milk (p<0.001). The oral chroma showed decreased hydrogen sulfide (p<0.001) and increased methyl mercaptan (p=0.009) and dimethyl sulfide (p=0.002) after drinking milk. In conclusion, halitosis cannot be modulated using water temperature for oral rinse. The findings of this study cannot be generalized because of the small sample size and the limits of age and sex. Further studies are required to extensively analyze both sexes and various age groups, with more number of subjects.

The Analysis of COVID-19 Pooled-Testing Systems with False Negatives Using a Queueing Model (대기행렬을 이용한 위음성률이 있는 코로나 취합검사 시스템의 분석)

  • Kim, Kilhwan
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.44 no.4
    • /
    • pp.154-168
    • /
    • 2021
  • COVID-19 has been spreading all around the world, and threatening global health. In this situation, identifying and isolating infected individuals rapidly has been one of the most important measures to contain the epidemic. However, the standard diagnosis procedure with RT-PCR (Reverse Transcriptase Polymerase Chain Reaction) is costly and time-consuming. For this reason, pooled testing for COVID-19 has been proposed from the early stage of the COVID-19 pandemic to reduce the cost and time of identifying the COVID-19 infection. For pooled testing, how many samples are tested in group is the most significant factor to the performance of the test system. When the arrivals of test requirements and the test time are stochastic, batch-service queueing models have been utilized for the analysis of pooled-testing systems. However, most of them do not consider the false-negative test results of pooled testing in their performance analysis. For the COVID-19 RT-PCR test, there is a small but certain possibility of false-negative test results, and the group-test size affects not only the time and cost of pooled testing, but also the false-negative rate of pooled testing, which is a significant concern to public health authorities. In this study, we analyze the performance of COVID-19 pooled-testing systems with false-negative test results. To do this, we first formulate the COVID-19 pooled-testing systems with false negatives as a batch-service queuing model, and then obtain the performance measures such as the expected number of test requirements in the system, the expected number of RP-PCR tests for a test sample, the false-negative group-test rate, and the total cost per unit time, using the queueing analysis. We also present a numerical example to demonstrate the applicability of our analysis, and draw a couple of implications for COVID-19 pooled testing.

Ag2Se Modified TiO2 Heterojunction with Enhanced Visible-Light Photocatalytic Performance

  • Zhu, Lei;Tang, Jia-Yao;Fan, Jia-Yi;Sun, Chen;Oh, Won-Chun
    • Korean Journal of Materials Research
    • /
    • v.31 no.12
    • /
    • pp.657-664
    • /
    • 2021
  • To build a highly active photocatalytic system with high efficiency and low cast of TiO2, we report a facile hydrothermal technique to synthesize Ag2Se-nanoparticle-modified TiO2 composites. The physical characteristics of these samples are analyzed by X-ray diffraction, scanning electron microscopy with energy dispersive X-ray analysis, transmission electron microscopy and BET analysis. The XRD and TEM results show us that TiO2 is coupled with small sized Ag2Se nanoplate, which has an average grain size of about 30 nm in diameter. The agglomeration of Ag2Se nanoparticles is improved by the hydrothermal process, with dispersion improvement of the Ag2Se@TiO2 nanocomposite. Texbrite BA-L is selected as a simulated dye to study the photodegradation behavior of as-prepared samples under visible light radiation. A significant enhancement of about two times the photodegradation rate is observed for the Ag2Se@TiO2 nanocomposite compared with the control sample P25 and as-prepared TiO2. Long-term stability of Ag2Se@TiO2 is observed via ten iterations of recycling experiments under visible light irradiation.

Chuna Manual Therapy for Postpartum Low Back Pain: Systematic Review (출산 후 요통에 대한 추나요법의 효과: 체계적 문헌고찰)

  • Cho, Ju-chan;Park, In-hwa;Hwang, Man-Suk;Heo, In
    • The Journal of Churna Manual Medicine for Spine and Nerves
    • /
    • v.16 no.2
    • /
    • pp.1-8
    • /
    • 2021
  • Objectives This study aimed to evaluate the effect of chuna manual therapy (CMT) for postpartum low back pain using a systematic review. Methods We performed a literature search using 12 electronic databases up to the end of September 2021. We included randomized controlled trials (RCTs) that evaluated the effect of CMT in the treatment of postpartum low back pain. The risk of bias was evaluated using the Cochrane risk-of-bias tool. Results Four randomized controlled trials were reported statistically significant effect in pain VAS, ODI and JOA of chuna manual therapy compared with moxibution, electro acupuncture, hyperthermia or usual care. As a result of assessing the risk of bias tool, most of the contents of the evaluation items were not identified, so it was evaluated as an uncertain risk. Conclusions CMT may be effective in treating postpartum low back pain. However, evidence was limited due to the small sample size, lack of well-designed RCTs and regional bias. Further well-designed studies are required to obtain stronger evidence.

The impact of COVID-19 on the male genital tract: A qualitative literature review of sexual transmission and fertility implications

  • Verrienti, Pierangelo;Cito, Gianmartin;Maida, Fabrizio Di;Tellini, Riccardo;Cocci, Andrea;Minervini, Andrea;Natali, Alessandro
    • Clinical and Experimental Reproductive Medicine
    • /
    • v.49 no.1
    • /
    • pp.9-15
    • /
    • 2022
  • The angiotensin-converting enzyme 2 receptor (ACE2) appears to be widely expressed in cells in the testes, predominantly in spermatogonia, Sertoli cells, and Leydig cells, and its co-expression with transmembrane protease serine 2 (TMPRSS2) is essential for the entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). For this reason, the male reproductive system could be considered a potential target for SARS-CoV-2, as well as a possible reservoir of infection. However, to date, there is very little evidence about the presence of SARS-CoV-2 in semen and testicular samples. The aim of this paper was to review the current evidence regarding the impact of SARS-CoV-2 on male fertility and sexual health, with a particular focus on reproductive hormones, the presence of the virus in seminal fluid and testis, and its impact on fertility parameters. We found very limited evidence reporting the presence of SARS-CoV-2 in semen and testicular samples, and the impact of SARS-CoV-2 on reproductive hormones and fertility parameters is unclear. The quality of the examined studies was poor due to the small sample size and several selection biases, precluding definitive conclusions. Hence, future well-designed prospective studies are needed to assess the real impact of SARS-CoV-2 on male reproductive function.

The Relationship on Risk Type, Risk Management and Business Performance - Evidence from Korean FDIs in China

  • Yin, Heng-Bin;Kim, Bo-Hyun;Jung, Hong-Joo
    • Journal of Korea Trade
    • /
    • v.23 no.5
    • /
    • pp.45-65
    • /
    • 2019
  • Purpose - As the well-known Structure-Conduct-Performance paradigm implies, risk structure of a corporation may affect its risk management activity and the activity may in turn determine its performance. Depending on its goal, Foreign Direct Investment (FDI) can shape its risk structure, risk management and its performance. Under this assumption, we investigate the relationship between the goals of FDI and risk management for the first time in academics. Design/methodology - This empirical research uses a survey of 279 current Korean enterprises' FDIs in China with the recently developed business risk quadrant model. Companies are classified into either a market- or an efficiency-seeking group, to identify how each group perceives and manages risks, and values the performance of risk management. Also, we apply integrated risk management method that multinational corporations have introduced in China, then verify the mediating effect between risk factors and performance. Findings - Our research shows the FDIs can expose themselves to differing risk structure although risk management activities simply represent the level of empowerment given to local management by headquarter due to limit of sample size despite diversity of risk and risk management tools. To sum, market seekers are found to have more strategic risk (revenue related risk) than efficiency seekers with financial risk (cost related risk). The market seekers can manage their risk by empowering their local organisation while the efficiency does the opposite ways. The risk management appears to be successful in general. Originality/value - Previous studies on small and medium enterprises' FDIs to China have concentrated on the analysis of entry determinants, withdrawal factors and individual risk management. Meanwhile, this research establishes enterprise-wide risk factors faced by the companies that advance into China, according to the method of the classification by ERM and verifies if they could synthetically improve performance through risk corresponding measures.

Fabrication of Ultramicroelectrodes with Nanoporous Gold Structures by Potentiostatic Anodization (정전위 양극 산화에 의한 나노다공성 금 구조의 초미세 전극 제작)

  • Seoin, Shin;Siyeon, Lee;Jongwon, Kim
    • Journal of the Korean Chemical Society
    • /
    • v.66 no.6
    • /
    • pp.436-441
    • /
    • 2022
  • Because the nanoporous electrodes has large electrochemical surface areas, extensive studies have been focused on their fabrication methods. In this paper, a method for introducing a nanoporous gold (NPG) structure on the surface of an ultramicroelectrode (UME) using potentiostatic anodization was investigated. A well-defined NPG structure was introduced on the surface of the UME when a potential of 1.3 V was applied in 0.1 M phosphate buffer solution (pH 8) containing 1 M KCl. The anodic oxidation efficiency was investigated by observing the effect of the applied potential, the reaction time, and the size of the electrode on the roughness factor (Rf) of the prepared NPG-UMEs. In a short time of about 10 minutes, NPG-UME with a large Rf value of about 2000 could be prepared, which could be effectively used for electrochemical glucose detection. The results shown in this work are expected to have great applicability when performing electrochemical analysis with a small sample volume.

Effects of Banhahubak-tang on Gastroesophageal Reflux Disease : A Systematic Review and Meta-Analysis (위식도역류질환에 대한 반하후박탕의 효과 : 체계적 문헌고찰과 메타분석)

  • Kang, Sieun;Kim, Kyoungmin;Jin, Myungho
    • Journal of Society of Preventive Korean Medicine
    • /
    • v.26 no.2
    • /
    • pp.11-24
    • /
    • 2022
  • Objectives : This study was designed to investigate the effect of Banhahubak-tang on gastroesophageal reflux disease(GERD) through a systematic review and meta-analysis of randomized controlled trials(RCTs). Methods : RCTs using Banhahubak-tang on GERD was searched in databases such as EMBASE, PubMed, MEDLINE, CENTRAL, CNKI, KISS, RISS, ScienceON, and OASIS. RCTs published up to October 8th, 2021 were included. Meta-analysis was performed by synthesizing outcome data, including Total Effectiveness Rate (TER), Reflux Symptom Index(RSI), Reflux Finding Score(RFS), and Incidence of Adverse Reactions. RevMan 5.4 software was used for data analysis. The Cochrane collaboration bias risk assessment scale was used to evaluate the methodological quality of the included studies. Results : Ten RCTs met the inclusion criteria. The total effective rate was the most commonly used outcome measure. The meta-analysis revealed that the TER in the experimental group was higher than that of the control group(N=2, RR:1.22, 95% CI:1.09 to 1.36, P=0.0004, I2=0%)(N=6, RR:1.22, 95% CI:1.14 to 1.32, P<0.00001, I2=0%)(N=8, RR:1.22, 95% CI: 1.14 to 1.30, P<0.00001, I2=0%). On the other hand, RSI(N=2, MD : -4.29, 95% CI: -4.71 to -3.86, I2=94%), RFS(N=2, MD : -3.28, 95% CI: -3.71 to -2.85, I2=96%), and Incidence of Adverse Reactions(N=5, RR: 0.32, 95% CI: 0.17 to 0.61, I2=0%) in the experimental group were lower than that of the control group. Conclusion : Treatment with Banhahubak-tang was found to be effective on GERD. However the results might be biased because of the poor quality and small sample size of the included RCTs.

Effectiveness of Acupuncture and Acupotomy for Trigger Finger: A Systematic Review and Meta-Analysis

  • Hae-Won Hong;Myung-In Jeong;Hyun-Il Jo;Sun-Ho Lee;Ka-Hyun Kim;Sung-Won Choi;Jae-Won Park;Ji-Su Ha
    • Journal of Acupuncture Research
    • /
    • v.40 no.2
    • /
    • pp.111-128
    • /
    • 2023
  • Trigger finger is a common cause of hand disability that results in finger catching, clicking, or locking. Conventional treatment options such as medication, injection, and surgery have limitations. Studies have indicated that acupuncture and acupotomy can be effective in treating trigger finger. However, no review regarding these treatment modalities has been published yet. This review included randomized controlled trials published until January 2023, investigating acupuncture-related interventions. The primary outcomes of interest included the effectiveness rate (ER) and pain intensity, measured using a visual analog scale (VAS) and Numerical Rating Scale (NRS), and secondary outcomes were the Quinnell grade (QG) and recurrence rate (RR). Adverse events (AEs) have also been reported wherever available. Overall, 19 studies were included, and results demonstrated that arcedge acupuncture improved the ER and QG and reduced NRS, and acupuncture was effective in reducing VAS. Compared with conventional surgery, acupotomy alone improved the ER and QG and lowered VAS and RR, with relatively fewer AEs. Acupotomy add-on treatment was more effective than conventional treatment; however, careful interpretation is needed for VAS. Acupotomy add-on treatment was more effective than acupotomy alone. However, the overall results must be interpreted with caution because of study quality, small sample size, and heterogeneity of the results.

A Systematic Review of the Effects of Robotic-Assisted Training on Gait Performance in Persons with Subacute Hemiparetic Stroke (아급성 편마비 뇌졸중 환자의 보행에 로봇-보조훈련이 미치는 영향에 관한 체계적 고찰)

  • Se-in Park;Su-jin Hwang
    • PNF and Movement
    • /
    • v.21 no.1
    • /
    • pp.1-10
    • /
    • 2023
  • Purpose: This systematic review aims to determine whether robot-assisted training is more effective in gait training for persons with subacute hemiparetic stroke. Methods: This study adopted a systematic review study design focused on subacute hemiparetic stroke, and four core academic databases were searched until June 11, 2021, for relevant studies, including PubMed, Embase, the Cochrane Library, and ProQuest Central. The review included randomized controlled trials (RCTs) evaluating the effects of robotic-assisted training on gait performance in persons with a diagnosis of subacute hemiparetic stroke. The selected RCT studies were qualitatively synthesized based on the population, intervention, comparison, outcome, settings, and study design (PICOS-SD). Results: The study selected five RCTs involving 253 subacute hemiparetic stroke patients and performing robotic-assisted gait training using the following devices: the Lokomat, Morning Walk, Walkbot, ProStep Plus, or Gait Trainer II. Five RCTs were eligible for the meta-analysis after quantitative synthesis, and the results showed that the robot-assisted gait training group had a greater gait performance than the control group based on the 10-meter walk test, Berg balance scale, Rivermed mobility index, functional ambulation category, and modified Barthel index. Conclusion: The results of this study showed that the gait performance of subacute hemiparetic stroke patients changes throughout robot-assisted gait training, but there were no indications that any of the clinically relevant effects of robot-assisted training are greater than those of conventional gait training. Further, the small sample size and different therapeutic intensities indicate that definitive conclusions could not be made.