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1.
Opt Lett ; 49(11): 2966-2969, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38824304

ABSTRACT

Over the past decades, spin qubits in silicon carbide (SiC) have emerged as promising platforms for a wide range of quantum technologies. The fluorescence intensity holds significant importance in the performance of quantum photonics, quantum information process, and sensitivity of quantum sensing. In this work, a dual-layer Au/SiO2 dielectric cavity is employed to enhance the fluorescence intensity of a shallow silicon vacancy ensemble in 4H-SiC. Experimental results demonstrate an effective fourfold augmentation in fluorescence counts at saturating laser power, corroborating our theoretical predictions. Based on this, we further investigate the influence of dielectric cavities on the contrast and linewidth of optically detected magnetic resonance (ODMR). There is a 1.6-fold improvement in magnetic field sensitivity. In spin echo experiments, coherence times remain constant regardless of the thickness of dielectric cavities. These experiments pave the way for broader applications of dielectric cavities in SiC-based quantum technologies.

2.
Polymers (Basel) ; 14(6)2022 Mar 16.
Article in English | MEDLINE | ID: mdl-35335532

ABSTRACT

An octa-screw extruder (OSE) is equipment for pelletizing, blending, and mixing polymers and composites. In this study, the degree of resin filling, residence time distribution (RTD) of molten resin, and temperature profile in the octa-screw extruder were evaluated both experimentally and numerically. An intermeshing corotating parallel octa-screw kneading extruder was used for the experiments. For the comparison study, the results obtained from this extruder were compared with the twin-screw extruder. High-density polyethylene was selected as the material for extrusion. Meanwhile, a numerical code, based on a 2.5 D finite element method derived from the Hele-Shaw flow model, was developed to simulate the octa-screw extrusion process. The empirical outcomes suggest that octa-screw extrusion exhibited a narrower RTD of the molten resin compared with the twin-screw extrusion, suggesting better extrudate quality. The octa-screw extrusion also showed a lower temperature profile than twin-screw extrusion. The results of the simulation were also found to be in good agreement with experimental measurements. Experimental and numerical investigations of an OSE enable detailed comprehension and visualization of resin distribution in the entire length of the OSE, thus providing advantages in terms of process optimization.

3.
BMC Gastroenterol ; 22(1): 69, 2022 Feb 18.
Article in English | MEDLINE | ID: mdl-35180851

ABSTRACT

BACKGROUND: Serum pepsinogen (PG) is recommended as a screening test for premalignant gastric lesions. However, real-world evidence demonstrating its applicability and equivalence between different test brands is limited. METHODS: Mass screening began in 2018 in a high-risk Taiwanese population after eradication of Helicobacter pylori, with the first stage of two PG tests (GastroPanel®, Helsinki, Finland and LZ-Test®, Tokyo, Japan) and the second stage of endoscopy. A positive test was defined as PG-I < 30 ng/mL or PG-I/II ratio < 3 for GastroPanel® and PG-I ≤ 70 ng/mL and PG-I/II ratio ≤ 3 for LZ-Test®. Index lesions included atrophic gastritis and intestinal metaplasia. Test performance was evaluated based on the participation rate, positivity rate, referral rate, positive predictive value (PPV), and the detection rate. RESULTS: Among 7616 eligible participants, 5117 (67.2%) received PG tests and 284 (5.6%) tested positive. Of those who tested positive, 105 (37.0%) underwent endoscopy. Overall PPVs for atrophic gastritis and intestinal metaplasia were 12.4% and 18.9%, respectively, with detection rates of 2.5 and 3.9 per 1000, respectively. Correlations of numerical measures between tests were high and the agreements of test results were substantial. The PPVs (16.3% vs. 16.3% and 23.8% vs. 21.3%, P = 1.00 and 0.71, respectively), detection rates (2.5 vs. 2.5 and 3.7 vs. 3.3 per 1000, P = 1.00 and 0.27, respectively), and the stage distributions of gastritis were all comparable, which were confirmed by multiple regression analyses. CONCLUSIONS: PG testing is effective for mass screening after eradication of H. pylori. Tests from different manufacturers, even using different analytical methods and cutoff criteria, can perform equivalently.


Subject(s)
Gastritis, Atrophic , Gastritis , Helicobacter Infections , Helicobacter pylori , Stomach Neoplasms , Gastritis/diagnosis , Gastritis, Atrophic/pathology , Helicobacter Infections/diagnosis , Helicobacter Infections/pathology , Humans , Pepsinogen A , Pepsinogen C , Stomach Neoplasms/diagnosis , Stomach Neoplasms/pathology
4.
Gut ; 70(2): 243-250, 2021 02.
Article in English | MEDLINE | ID: mdl-32792335

ABSTRACT

OBJECTIVE: Although mass eradication of Helicobacter pylori has been proposed as a means to eliminate gastric cancer, its long-term effects remain unclear. DESIGN: Mass eradication of H. pylori infection was launched in 2004 and continued until 2018 for a high-risk Taiwanese population aged 30 years or older dwelling on Matsu Islands with prevalent H. pylori infection. Test positives for the 13C-urea breath test underwent eradication therapy. We evaluated the effectiveness of the mass eradication in reducing two main outcomes, incidence and mortality rates of gastric cancer, until the end of 2016 and 2018, respectively. RESULTS: After six rounds of mass screening and eradication, the coverage rate reached 85.5% (6512/7616). The referral rate for treatment was 93.5% (4286/4584). The prevalence rates of H. pylori fell from 64.2% to 15.0% with reinfection rates of less than 1% per person-year. The presence and severity of atrophic gastritis and intestinal metaplasia also decreased with time. Compared with the historical control period from 1995 to 2003, the effectiveness in reducing gastric cancer incidence and mortality during the chemoprevention period was 53% (95% CI 30% to 69%, p<0.001) and 25% (95% CI -14% to 51%, p=0.18), respectively. No significant changes were noted in the incidence rates of other digestive tract cancers or the antibiotic resistance rate of H. pylori. CONCLUSION: Population-based eradication of H. pylori has significantly reduced gastric cancer incidence with no increase in the likelihood of adverse consequences. A significant reduction in mortality is likely to be achieved with a longer follow-up period. TRIAL REGISTRATION NUMBER: NCT00155389.


Subject(s)
Disease Eradication , Helicobacter Infections/prevention & control , Helicobacter pylori , Stomach Neoplasms/prevention & control , Anti-Bacterial Agents/therapeutic use , Disease Eradication/methods , Female , Gastroscopy , Helicobacter Infections/drug therapy , Helicobacter Infections/epidemiology , Humans , Incidence , Male , Mass Screening , Middle Aged , Stomach Neoplasms/epidemiology , Stomach Neoplasms/mortality , Taiwan/epidemiology
5.
J Gastroenterol Hepatol ; 36(3): 671-679, 2021 Mar.
Article in English | MEDLINE | ID: mdl-32671873

ABSTRACT

BACKGROUND AND AIM: The reliable method to stratify the gastric cancer risk after Helicobacter pylori eradication remains an elusive goal. METHODS: Mass eradication of H. pylori began in 2004 in a high-risk population. After eradication, a screening program involving first-stage serological tests (pepsinogen-I, pepsinogen-II, H. pylori immunoglobin G, and gastrin-17) and second-stage endoscopic examination was launched in 2015-2018. Index lesions included gastric cancer or extensive premalignant lesions. We evaluated the performance of the serological tests to "rule in" and "rule out" the risk based on positive and negative likelihood ratios, respectively. The methylation levels of microRNA-124a-3 in the stomach were measured to indicate genetic damage. RESULTS: Among 6512 invited subjects, 3895 (59.6%) participated. Both gastrin-17 and pepsinogen tests were normal in 3560 (91.4%) subjects; 206 (5.3%) gastrin-17 and 129 (3.3%) pepsinogen tests were abnormal. Years after eradication, the severity of gastritis had fallen greatly, and extensive premalignant lesions or gastric cancer frequently occurred in newly non-atrophic-appearing mucosa. Pepsinogen testing could moderately predict atrophic gastritis (positive likelihood ratio: 4.11 [95% confidence interval: 2.92-5.77]; negative likelihood ratio: 0.14 [0.10-0.19]). Gastrin-17 was not useful (0.66 and 1.20, respectively). However, pepsinogen testing poorly predicted the index lesions (2.04 [1.21-3.42] and 0.57 [0.34-0.95]). DNA methylation levels in the post-eradication mucosa were more discriminative for predicting index lesions (3.89 [2.32-6.54] and 0.25 [0.15-0.42]). CONCLUSIONS: After eradication, pepsinogen false-negative results become more frequent because histology is improved but genetic damage may persist. Direct testing for genetic damage offers better discrimination.


Subject(s)
Gastritis/drug therapy , Gastritis/microbiology , Helicobacter Infections , Helicobacter pylori , Risk Assessment/methods , Stomach Neoplasms/etiology , Biomarkers/metabolism , DNA Methylation , False Negative Reactions , Female , Gastric Mucosa/metabolism , Gastritis/diagnosis , Gastritis/genetics , Humans , Male , MicroRNAs/metabolism , Pepsinogen A/metabolism , Risk , Risk Factors , Serologic Tests , Severity of Illness Index
6.
Front Microbiol ; 11: 1118, 2020.
Article in English | MEDLINE | ID: mdl-32582082

ABSTRACT

The type VI secretion system (T6SS) is a widespread bacterial nanoweapon used for delivery of toxic proteins into cell targets and contributes to virulence, anti-inflammatory processes, and interbacterial competition. In the model phytopathogenic bacterium Pseudomonas syringae pv. tomato (Pst) DC3000, two T6SS gene clusters, HSI-I and HSI-II, were identified, but their functions remain unclear. We previously reported that hcp2, located in HSI-II, is involved in competition with enterobacteria and yeast. Here, we demonstrated that interbacterial competition of Pst DC3000 against several Gram-negative plant-associated bacteria requires mainly HSI-II activity. By means of a systematic approach using in-frame deletion mutants for each gene in the HSI-II cluster, we identified genes indispensable for Hcp2 expression, Hcp2 secretion and interbacterial competition ability. Deletion of PSPTO_5413 only affected growth in interbacterial competition assays but not Hcp2 secretion, which suggests that PSPTO_5413 might be a putative effector. Moreover, PSPTO_5424, encoding a putative σ54-dependent transcriptional regulator, positively regulated the expression of all three operons in HSI-II. Our discovery that the HSI-II gene cluster gives Pst DC3000 the ability to compete with other plant-associated bacteria could help in understanding a possible mechanism of how phytopathogenic bacteria maintain their ecological niches.

7.
J Clin Gastroenterol ; 53(5): e186-e193, 2019.
Article in English | MEDLINE | ID: mdl-29369241

ABSTRACT

GOALS: The purpose of this article is to validate the long-term association between initial serum pepsinogen (PG) measurements and subsequent gastric cancer-specific deaths from a long-term longitudinal cohort. BACKGROUND: Endoscopic surveillance can be effective and efficient in reducing gastric cancer mortality if a biomarker such as serum PG is available to identify high-risk individuals and if the biomarker also is specific to gastric cancer risk. STUDY: Between 1995 and 1998, a gastric cancer-screening program was conducted in a high-risk population: The first stage involved PG testing, and the second stage involved upper endoscopy. The outcome was gastric cancer death, which was monitored until December 31, 2010; results were expressed as the hazard ratio (HR) and corresponding 95% confidence interval (CI) using the Cox proportional hazards regression model. Other causes of death were used as comparators. RESULTS: Among participants (n=3514) aged ≥30 years, 1682 (47.9%) were screened to determine serum PG levels. After 16 years of follow-up, 14 deaths from gastric cancer were documented. Multivariate analyses adjusted for age, sex, and Helicobacter pylori serological positivity showed that PG-I <30 µg/L and PG-I <30 µg/L or PG-I/II ratio <3 were significantly associated with the risk of gastric cancer death (HR, 3.27; 95% CI, 1.11-9.61 and HR, 3.45; 95% CI, 1.18-10.12, respectively). In contrast, there were no significant associations between PG and other causes of death, including neoplastic and non-neoplastic diseases. CONCLUSION: This long-term cohort study shows the usefulness of PG measurement as a biomarker that is specific to the risk of gastric cancer death.


Subject(s)
Pepsinogen A/blood , Stomach Neoplasms/epidemiology , Adult , Aged , Aged, 80 and over , Biomarkers, Tumor/blood , Cohort Studies , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Stomach Neoplasms/blood , Stomach Neoplasms/diagnosis , Stomach Neoplasms/mortality , Taiwan/epidemiology
8.
Article in English | MEDLINE | ID: mdl-16874440

ABSTRACT

We investigated the perception of nocturia and possible explanatory factors for medical consultation among community-dwelling women. Between October 2004 and February 2005, women aged > or =40 years living in Matsu, Taiwan, who were identified as having nocturia in a previous epidemiological survey, were interviewed with a questionnaire eliciting information about nocturia-specific quality of life impact (N-QOL), perceptions of nocturia, and medical-consultation behavior. A total of 328 women completed this study. Of these, 187 (57%), 99 (30.2%), 30 (9.1%), and 12 (3.7%) reported one, two, three, and four or more nocturia episodes, respectively, per night during the past 4 weeks. Most women attributed nocturia to aging or excessive fluid intake and had a lack of medical information. Overall, only 13.1% had visited a doctor for this condition. Nocturia episodes [> or = three vs

Subject(s)
Health Knowledge, Attitudes, Practice , Nocturia/psychology , Patient Acceptance of Health Care , Adult , Aged , Cohort Studies , Female , Health Surveys , Humans , Middle Aged , Nocturia/therapy , Quality of Life , Taiwan , Treatment Outcome
9.
Urol Int ; 77(4): 327-33, 2006.
Article in English | MEDLINE | ID: mdl-17135783

ABSTRACT

PURPOSE: We investigated the prevalence, correlates, perception of overactive bladder syndrome (OAB) and doctor-consultation behavior among community adults. SUBJECTS AND METHODS: This urological survey was part of a government-supported health utilization project conducted in Matsu, Taiwan. Participants (n = 1,827) completed a questionnaire collecting information on OAB, which was defined as urgency with either frequency or nocturia. RESULTS: The age-adjusted prevalence of OAB was 16.9%, including 4.5% with urge incontinence. Age (p = 0.002), diabetes (p = 0.03), and benign prostatic hyperplasia (p < 0.001) in men, whereas diabetes (p = 0.01), hyperlipidemia (p = 0.03), stress incontinence (p < 0.001), and recurrent lower urinary tract infections (p = 0.02) in women were factors independently associated with OAB. Most people with OAB (69.0%) perceived little bother; only 13.0% had consulted doctors for this problem. CONCLUSION: Symptoms related to OAB are common among community-dwelling adults, yet most perceive it as a minor problem. Our results identify several factors that are significantly associated with OAB.


Subject(s)
Patient Acceptance of Health Care/statistics & numerical data , Population Surveillance , Urinary Bladder, Overactive/epidemiology , Urinary Bladder, Overactive/therapy , Adult , Age Distribution , Aged , Female , Humans , Male , Middle Aged , Prevalence , Retrospective Studies , Sex Distribution , Syndrome , Taiwan/epidemiology
10.
Urology ; 67(4): 713-8, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16566966

ABSTRACT

OBJECTIVES: To evaluate factors predicting the effect of nocturia in a community-based cohort of adults using a nocturia-specific quality-of-life (N-QOL) questionnaire. METHODS: From October 2004 to February 2005, adults aged 40 years old or older living in Matsu, Taiwan and reporting nocturia of one episode or more per night were interviewed with a 12-item N-QOL questionnaire consisting of Sleep/Energy and Bother/Concern subscales. Univariate analyses were used to analyze the effects of demographic characteristics, frequency and duration of nocturia, and sleeping characteristics on the N-QOL score. Multiple linear regression analysis was used to identify factors predicting the N-QOL score. RESULTS: A total of 663 adults completed this study (mean age 59.4 years). The average N-QOL scores (a lower score indicates worse QOL) were 91.4 +/- 11.2, 83.7 +/- 13.2, 77.6 +/- 16.8, and 67.6 +/- 21.2 for nocturia episodes of 1, 2, 3, and 4 or more per night, respectively (P < 0.001). Men reported significantly lower N-QOL (85.6 +/- 15.1 versus 88.9 +/- 13.1, P = 0.003) and Bother/Concern subscale scores (42.0 +/- 8.4 versus 44.0 +/- 7.4, P < 0.001), but not Energy/Sleep subscale scores (43.6 +/- 7.8 versus 44.4 +/- 7.3, P = 0.158) than women. On multiple linear regression analysis, increasing nocturia episodes (regression coefficient -6.2, 95% confidence interval -7.4 to -5.0), male sex (regression coefficient -3.5, 95% confidence interval -5.4 to -1.5), and degree of sleeping disturbance after nocturia (regression coefficient -4.5, 95% confidence interval -5.6 to -3.4) independently predicted a significantly lower N-QOL score. CONCLUSIONS: The results of our study have confirmed that nocturia has a more significant QOL impact when the patient has two or more episodes per night. Moreover, men experienced a greater impact from nocturia than women, particularly in the Bother/Concern domain.


Subject(s)
Quality of Life , Urination Disorders , Adult , Aged , Female , Humans , Male , Middle Aged , Surveys and Questionnaires
11.
J Med Screen ; 13 Suppl 1: S2-5, 2006.
Article in English | MEDLINE | ID: mdl-17227633

ABSTRACT

Although multistate progression models for gastric cancer have been proposed, estimation of quantitative parameters of such models is yet to be done. The present study was conducted to elucidate risk factors for gastric cancer and its precursors, and to model the progression rates from superficial gastritis to gastric cancer. Data were derived from a community-based screening programme for gastric cancer in the Matzu region of Taiwan. A total of 2184 residents participated in a two-stage screening project. Subjects testing positive for Helicobacter pylori infection or pepsinogen (PGI or PII/PGII ratio) and immunoglobulin G (IgG), and subjects with a history of peptic ulcer or other upper gastrointestinal disease or with a family history of gastric cancer were referred to endoscopy. We identified 325 biopsy-proven precursors and gastric cancers, including 148 superficial gastritis (SG), 42 atrophic gastritis (AG), 117 intestinal metaplasia (IM) and two gastric cancers. Three further cancers were diagnosed on endoscopy alone and 14 were later diagnosed in those who did not comply with referral to endoscopy. A Markov process model was used to estimate the progression rates from superficial gastritis through to gastric cancer, with exponential regression to assess the effect of covariates on progression rates. The annual progression rate from SG to AG was 0.0670 (95% confidence interval [CI] 0.0446-0.0895). Annual progression rates from AG to IM and from IM to gastric cancer were 0.2775 (0.1665-0.3884) and 0.2265 (0.1315-0.3214), respectively. This gives average dwelling times in AG and IM of 3.60 years and 4.42 years, respectively. Progression from no disease to SG was significantly accelerated in those testing positive for H. pylori, those testing positive for PGI and in subjects with a family history of gastric cancer or a personal history of upper gastrointestinal disease. Further progression to AG and IM was significantly accelerated in those testing positive for PGI and in those with a history of upper gastrointestinal disease.


Subject(s)
Mass Screening/methods , Stomach Neoplasms/diagnosis , Adult , Aged , Aged, 80 and over , Disease Progression , Female , Gastritis/diagnosis , Gastroscopy/methods , Gastroscopy/statistics & numerical data , Humans , Male , Markov Chains , Mass Screening/statistics & numerical data , Middle Aged , Models, Statistical , Precancerous Conditions/diagnosis , Risk Factors , Taiwan
12.
J Formos Med Assoc ; 104(6): 444-7, 2005 Jun.
Article in English | MEDLINE | ID: mdl-16037837

ABSTRACT

The aims of this study were to investigate the prevalence of nocturia among adults residing in the Matsu area of Taiwan, and to examine the association of this condition with sociodemographic and health characteristics. Between October 2002 and February 2003, all adults older than 30 years residing in the Matsu area were invited to participate in a health awareness campaign. A total of 1706 adults aged 30 to 91 years completed the study survey. Among them, 16.8% reported nocturia with > or = 2 voids per night. The prevalence of nocturia increased with age from 8.4% in the 30-39 years age group to 30.9% in the > or = 70 years age group (p < 0.001). No significant difference of nocturia prevalence was found between men and women. In addition to age, diabetes (odds ratio, 2.5; 95% confidence interval, 1.4-4.2) was also independently associated with nocturia. This study suggests the importance of nocturia as a health problem and the need for greater awareness and treatment.


Subject(s)
Urination Disorders/epidemiology , Adult , Age Factors , Aged , Female , Humans , Male , Middle Aged , Prevalence , Prostatic Hyperplasia/complications , Taiwan/epidemiology , Urination Disorders/etiology
13.
J Formos Med Assoc ; 101(12): 835-40, 2002 Dec.
Article in English | MEDLINE | ID: mdl-12632816

ABSTRACT

BACKGROUND AND PURPOSE: People living on Matzu, a group of small islets, have the highest mortality rate from gastric cancer (GC) in Taiwan. Intestinal metaplasia (IM) is a precursor lesion of GC. We therefore conducted a gastroscopic screening program in this district to evaluate the risk factors associated with IM. METHODS: A total of 274 residents of Matzu, aged 30 years or older, underwent testing for anti-Helicobacter pylori IgG antibody and serum pepsinogen (PG) I/PG II levels, and gastroscopic examination. Univariate and multivariate logistic regression models were used to identify risk factors associated with IM in terms of odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Among the 274 subjects, 118 (43%) were confirmed to have IM by histologic examination. Individuals aged 60 years or older had a 2.66 times higher risk (95% CI 1.38-5.13) of having IM, as compared with those less than 60 years of age. Subjects with duodenal ulcer had a 60% lower risk of coexisting IM (OR, 0.40; 95% CI, 0.19-0.83). Meanwhile, subjects with gastric ulcer were not at increased risk of IM (OR, 0.84; 95% CI, 0.34-2.08). Low serum PG I level, low PG I/PG II ratio, and positive anti-H. pylori IgG antibody, were associated with IM in the univariate analysis. While age and duodenal ulcer maintained their independent effects in the multivariate analysis, only a low PG I/PG II ratio and H. pylori positivity were significantly associated with IM. CONCLUSIONS: This study of residents of Matzu found that age and H. pylori infection are risk factors for IM, while subjects with duodenal ulcer have a lower incidence of coexisting IM. Low PG I/PG II ratio is a potential noninvasive biomarker of IM.


Subject(s)
Intestines/pathology , Precancerous Conditions/diagnosis , Stomach Neoplasms/diagnosis , Adult , Aged , Antibodies, Bacterial/blood , Cross-Sectional Studies , Female , Helicobacter pylori/immunology , Humans , Immunoglobulin G/blood , Male , Metaplasia/diagnosis , Middle Aged , Pepsinogen A/blood , Risk Factors , Taiwan/epidemiology
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