Simultaneous electrochemical determination of uric acid and hypoxanthine at a TiO2/graphene quantum dot-modified electrode.

A TiO2/graphene quantum dots composite (TiO2/GQDs) obtained by in situ synthesis of GQDs, derived from coffee grounds, and peroxo titanium complexes was used as electrode modifier in the simultaneous electrochemical determination of uric acid and hypoxanthine. The TiO2/GQDs material was characterized by photoluminescence, X-ray diffraction, Raman spectroscopy, high-resolution transmission electron microscopy, and energy-dispersive X-ray mapping. The TiO2/GQDs-GCE exhibits better electrochemical activity for uric acid and hypoxanthine than GQDs/GCE or TiO2/GCE in differential pulse voltammetry (DPV) measurements. Under optimized conditions, the calibration plots were linear in the range from 1.00 to 15.26 µM for both uric acid and hypoxanthine. The limits of detection of this method were 0.58 and 0.68 µM for uric acid and hypoxanthine, respectively. The proposed DPV method was employed to determine uric acid and hypoxanthine in urine samples with acceptable recovery rates.

Prospective Comparison of VisuALL Virtual Reality Perimetry and Humphrey Automated Perimetry in Glaucoma.

Aim and background: Automated perimetry plays an important role in the diagnosis and monitoring of glaucoma patients. The purpose of this study is to prospectively determine parity between Humphrey visual field analyzer (HVFA) perimetry (the current gold standard) and the VisuALL virtual reality perimeter (VRP). Materials and methods: In this prospective fully paired diagnostic accuracy study, patients with stable, long-term HVFA visual fields (horizontal dots for ≥4 consecutive visits on progression analysis) with preperimetric, mild, moderate, or severe visual field loss were familiarized with the VRP and then tested using its proprietary software. These results were used for point-by-point comparison with a contemporaneous HVFA test. This study was approved by the Institutional Review Board (IRB) of the University of the Incarnate Word, San Antonio, Texas, United States of America (IRB approval #20-06-002). Results: The prospective study analyzed 43 eyes of 24 glaucoma patients. Spearman's correlation of mean deviation (MD) revealed a strong correlation between HVFA and VRP with rs(41) = 0.871, p < 0.001. The overall mean difference in locus-locus sensitivity between the devices was -0.4 ± 1.5 dB but varied for different visual field locations and glaucoma severity. Conclusion: The parity between the VRP and HVFA was remarkably strong for mild and moderate glaucoma. Given its portability, ease of use, space efficiency, and low cost, the VRP presents a viable alternative. Clinical significance: Automated perimetry, specifically the HVFA, has been the gold standard for visual field assessment since its introduction. The recent COVID-19 pandemic has illuminated the advantages of the VRP, allowing for safer visual assessment for both patient and clinician alike. Our study hopes to establish parity between these systems, allowing for the efficient integration of a novel head-mounted perimetry system that can safely diagnose and monitor glaucomatous progression in clinical practice. Precis: Investigation of parity between Olleyes VisuALL virtual reality perimetry (VRP) and existing standard HVFA perimetry is essential to the diagnosis and management of glaucoma. Linear correlations between the two were established from 43 glaucomatous eyes. Parity was strong for mild and moderate glaucoma, presenting VRP as a viable alternative. How to cite this article: Griffin JM, Slagle GT, Vu TA, et al. Prospective Comparison of VisuALL Virtual Reality Perimetry and Humphrey Automated Perimetry in Glaucoma. J Curr Glaucoma Pract 2024;18(1):4-9.

Deep Learning and Machine Learning Algorithms for Retinal Image Analysis in Neurodegenerative Disease: Systematic Review of Datasets and Models.

Purpose: Retinal images contain rich biomarker information for neurodegenerative disease. Recently, deep learning models have been used for automated neurodegenerative disease diagnosis and risk prediction using retinal images with good results. Methods: In this review, we systematically report studies with datasets of retinal images from patients with neurodegenerative diseases, including Alzheimer's disease, Huntington's disease, Parkinson's disease, amyotrophic lateral sclerosis, and others. We also review and characterize the models in the current literature which have been used for classification, regression, or segmentation problems using retinal images in patients with neurodegenerative diseases. Results: Our review found several existing datasets and models with various imaging modalities primarily in patients with Alzheimer's disease, with most datasets on the order of tens to a few hundred images. We found limited data available for the other neurodegenerative diseases. Although cross-sectional imaging data for Alzheimer's disease is becoming more abundant, datasets with longitudinal imaging of any disease are lacking. Conclusions: The use of bilateral and multimodal imaging together with metadata seems to improve model performance, thus multimodal bilateral image datasets with patient metadata are needed. We identified several deep learning tools that have been useful in this context including feature extraction algorithms specifically for retinal images, retinal image preprocessing techniques, transfer learning, feature fusion, and attention mapping. Importantly, we also consider the limitations common to these models in real-world clinical applications. Translational Relevance: This systematic review evaluates the deep learning models and retinal features relevant in the evaluation of retinal images of patients with neurodegenerative disease.

Expanded vaccination practice in 2-year-old children and maternal knowledge on expanded vaccination in Tien Giang, Vietnam.

Background: Vaccination plays a central role in protecting children against severe diseases and preventing child mortality. Objectives: This study aimed to determine the rate and factors associated with complete and timely vaccination in 2-year-old children, as well as maternal knowledge on expanded vaccination in Go Cong Tay district, Tien Giang province, Vietnam. Methods: A cross-sectional descriptive study was conducted on 558 2-year-old children and their mothers residing in Go Cong Tay district, Tien Giang province, Vietnam. The study employed a systematic random sampling method from June to September 2021. Results: The rate of complete vaccination in children was 74.7%. Factors associated with the rate of complete vaccination were occupation (OR=0.3; 95%CI: 0.1-0.7; p=0.006), economic status (OR=3.8; 95%CI: 1.7-8.6; p=0.001), and maternal general knowledge on expanded vaccination (OR=1.7; 95%CI: 1.1-2.6; p=0.01). The rate of timely vaccination was 47.8%. Factors associated with the rate of timely vaccination were maternal age group (OR=3.1; 95%CI: 1.6-6.0; p=0.001; OR=3.0; 95%CI: 1.3-6.6; p=0.006) and economic status (OR=0.4; 95%CI: 0.2-0.9; p=0.04). The rate of both complete and timely vaccination was 22.6%. Factors associated with the rate of complete and timely vaccination were maternal age group (OR=3.1; 95%CI: 1.3-7.2; p=0.009; OR=3.3; 95%CI: 1.2-9.1; p=0.02) and maternal general knowledge on expanded vaccination (OR=1.5; 95%CI: 1.0-2.4; p=0.03). The rate of maternal general knowledge on expanded vaccination was 57.5%. Conclusion: The rates of complete and timely vaccination are still low, and various factors influence expanded vaccination. The-refore, it is crucial to continue health education campaigns to improve knowledge on expanded vaccination, remind mothers of vaccination schedules, strengthen confidence in vaccination programs and vaccine safety, attract customers to vaccination services, provide adequate healthcare for children, and ensure vaccination activities during disease outbreaks.

mHealth application for improving treatment outcomes for patients with multidrug-resistant tuberculosis in Vietnam: an economic evaluation protocol for the V-SMART trial.

INTRODUCTION: The Strengthen the Management of Multidrug-Resistant Tuberculosis in Vietnam (V-SMART) trial is a randomised controlled trial of using mobile health (mHealth) technologies to improve adherence to medications and management of adverse events (AEs) in people with multidrug-resistant tuberculosis (MDR-TB) undergoing treatment in Vietnam. This economic evaluation seeks to quantify the cost-effectiveness of this mHealth intervention from a healthcare provider and societal perspective. METHODS AND ANALYSIS: The V-SMART trial will recruit 902 patients treated for MDR-TB across seven participating provinces in Vietnam. Participants in both intervention and control groups will receive standard community-based therapy for MDR-TB. Participants in the intervention group will also have a purpose-designed App installed on their smartphones to report AEs to health workers and to facilitate timely management of AEs. This economic evaluation will compare the costs and health outcomes between the intervention group (mHealth) and the control group (standard of care). Costs associated with delivering the intervention and health service utilisation will be recorded, as well as patient out-of-pocket costs. The health-related quality of life (HRQoL) of study participants will be captured using the 36-Item Short Form Survey (SF-36) questionnaire and used to calculate quality-adjusted life-years (QALYs). Incremental cost-effectiveness ratios (ICERs) will be based on the primary outcome (proportion of patients with treatment success after 24 months) and QALYs gained. Sensitivity analysis will be conducted to test the robustness of the ICERs. A budget impact analysis will be conducted from a payer perspective to provide an estimate of the total budget required to scale-up delivery of the intervention. ETHICS AND DISSEMINATION: Ethical approval for the study was granted by the University of Sydney Human Research Ethics Committee (2019/676), the Scientific Committee of the Ministry of Science and Technology, Vietnam (08/QD-HDQL-NAFOSTED) and the Institutional Review Board of the National Lung Hospital, Vietnam (13/19/CT-HDDD). Study findings will be published in peer-reviewed journals and conference proceedings. TRIAL REGISTRATION NUMBER: ACTRN12620000681954.

Assessing prescriber adherence with Global Initiative for Asthma (GINA) guideline-recommended reliever therapy.

In 2019, a landmark change was made to the Global Initiative for Asthma (GINA) guidelines in which an as-needed low-dose inhaled corticosteroid (ICS)-formoterol inhaler was updated to be the preferred reliever therapy for all asthma patients. Use of short-acting beta-agonist monotherapy is no longer recommended. The purpose of this study was to assess provider adherence with the GINA guidelines in regards to reliever therapy. This was a retrospective cohort study of patients presenting with an acute asthma exacerbation from January to May of 2020 and 2021. The primary objective of this study was to quantify provider adherence with the GINA guidelines in terms of reliever therapy. Preferred reliever therapy was defined as use of an as-needed low-dose ICS-formoterol combination inhaler. Alternative reliever therapy was defined as use of a SABA inhaler with ICS-containing controller therapy. Secondary objectives included the number of patients discharged on any form of corticosteroid and the number of patients who may have been ideal candidates for transition to preferred reliever therapy. A total of 127 patients were included in the analyses. Upon hospital discharge, three patients (2.4%) received preferred reliever therapy and 97 (76.4%) received alternative reliever therapy. Rates of recommended reliever therapy prescription increased from 55 to 79% upon hospital discharge (p < 0.001). Prescription of GINA guideline-recommended reliever therapy was 79% within the patient population evaluated; however, rates significantly improved following hospitalization for asthma exacerbation. Additional studies that assess barriers to guideline adherence may be recommended.

COVID-19 Related Acute Macular Neuroretinopathy (AMN): A Case Series.

Purpose: Following the emergence of coronavirus disease 2019 (COVID-19) eye care practitioners have become accustomed to identifying and managing an array of ocular complications following the viral infection. Acute macular neuroretinopathy (AMN) is one such complication that has been reported. While the etiology of AMN has eluded researchers, current literature is suggestive of a microvascular compromise within the deep capillary plexus of the retina. Observations: In this case series, we aim to explore two individual cases of presumed AMN following confirmed COVID-19 infection. Our observations and findings support the diagnosis of AMN following the criteria outlined in literature. Conclusion and Importance: Although acute macular neuroretinopathy is rare, it should be considered by clinicians when considering diagnosis. With the changing landscape of the pandemic, careful and thorough history and testing are key in the diagnosis of AMN.

Personality Traits and Aggressive Behavior in Vietnamese Adolescents.

Purpose: This study aims to reveal the relationship between personality characteristics and verbal or physical aggression in Vietnamese adolescents. Patients and Methods: We recruited 3003 participants [1498 boys (49.9%) and 1505 girls (50.1%); mean age ± SD = 13.50 ± 0.936] who we tested with the Eysenck Personality Questionnaire - Brief version (EPQ-BV), and Vietnamese Aggression Scale (VAS). A multivariate analysis of variance test, Pearson Correlation, and analyzing mediating variable interaction is used to analyze data. Results: The findings suggested a significant interaction between personality traits, specifically extraversion and neuroticism, and physical aggression, verbal aggression, and anger. Students with higher levels of personality had higher levels of verbal aggression, and students with higher levels of physical aggression and anger had stronger personality traits than others and lower levels of physical aggression and anger. Personality traits, specifically extraversion, and neuroticism, differed significantly by gender and school years in adolescence. Mediation analysis revealed a positive and statistically significant indirect correlation between personality traits and physically aggressive behavior, with anger as a mediator. Similarly, a positive and statistically significant indirect correlation between personality traits and verbally aggressive behavior through anger was found. The relationship between personality traits and physical aggression was also significant via verbal aggression and anger. Conclusion: This study improved our understanding of personality traits and verbal or physical aggression. Most crucially, physical and verbal aggression mediate personality traits and aggressive conduct. In secondary school, gender and school year affected extraversion and neuroticism. This discovery illuminates personality-based aggressiveness intervention.

Reduction of the skin­effect dose of IMRT plan for patients with cancer in pelvic region.

In the present study, it was aimed to investigate the optimized plan of radiotherapy with dose modulation in the pelvis to reduce the dose on the skin in patients having pelvic region radiotherapy. The series of images of 45 pelvic cancer patients were selected, intensity-modulated radiation therapy (IMRT) plan was made, the skin dose reduction was optimized, and evaluated verifying the plan verification. As a result, skin volume receiving dose ≥10, ≥20, ≥30, ≥40 and ≥50 Gy of the IMRT Skin plan were all less than those of the IMRT plan. Particularly, skin volumes receiving doses ≥20, ≥30, ≥40 and ≥50 Gy of the Skin IMRT plan were markedly lower than those of the IMRT plan, the reduction values were 8.76, 18.83, 46.84 and 100%, respectively. Furthermore, the Skin IMRT plan was no longer affected by the 50 Gy dose. In conclusion, the present study revealed that the skin's dose can be decreased with optimal plan processing; thus, this decrease of the skin's dose ensures the continuation of radiotherapy and improved life quality of the patient.

Tracheal reconstruction surgery for congenital tracheal stenosis.

PURPOSE: Congenital tracheal stenosis is a rare but dangerous disease. Reconstructive tracheal surgery is a life-saving treatment but also a challenging procedure. This study aims to evaluate the outcomes of tracheal reconstruction surgery. METHODS: A prospective cohort study was conducted with all the records of congenital tracheal stenosis which had been managed by tracheal reconstruction surgery at Children's Hospital 2 Ho Chi Minh City from August 2013 to August 2022. RESULTS: Sixty-seven cases, who underwent slide tracheoplasty, were included in our study. Mean age was 7.6 months (25 days - 8 years). Common congenital-associated lesion was left pulmonary artery sling, accounting for 65.7% of cases. Bronchial stenosis was found in 22.4% patients. Emergency surgery was performed in eight cases. The survival rate in this review was 86.6%. Nine patients died in which four of nine cases (44.4%) were emergency surgery. The recurrent stenosis rate was 8.9%, only two cases needed reoperation in which one died and one recovered uneventfully. The outcomes of surgery were good in 53 cases (79.1%). CONCLUSION: Tracheal reconstruction surgery with slide tracheoplasty technique is safe and versatile technique which is feasible in every case of congenital tracheal stenosis. Mortality was associated with severe cases which required emergency surgery.

Fluctuating Voriconazole Concentrations during Extracorporeal Membrane Oxygenation.

BackgroundPatients requiring extracorporeal membrane oxygenation (ECMO) demonstrate complex drug pharmacokinetics due to alterations in clearance and volume of distribution, necessitating close therapeutic drug monitoring. Case Report: A 19-year-old Caucasian female with no past medical history was transferred from an outside hospital and admitted to the intensive care unit for acute respiratory distress syndrome secondary to a fresh water drowning event. The patient decompensated, requiring veno-arterial ECMO, which was subsequently changed to veno-venous ECMO. She was diagnosed with a Scedosporium apiospermum fungal pneumonia and was started on voriconazole. Throughout the course of antifungal therapy, the patient's voriconazole concentrations were labile, ranging from subtherapeutic, requiring dose increases to twice the labeled therapeutic dose, followed by subsequent supratherapeutic concentrations, requiring dose reductions. Conclusion: Our findings demonstrate how voriconazole drug concentrations can be unpredictable when administered during ECMO and the importance of close monitoring of drug concentrations. More studies are needed to provide sufficient guidance on administering voriconazole in critically ill patients receiving ECMO.

Quadcopter UAVs Extended States/Disturbance Observer-Based Nonlinear Robust Backstepping Control.

A trajectory tracking control for quadcopter unmanned aerial vehicle (UAV) based on a nonlinear robust backstepping algorithm and extended state/disturbance observer (ESDO) is presented in this paper. To obtain robust attitude stabilization and superior performance of three-dimension position tracking control, the construction of the proposed algorithm can be separated into three parts. First, a mathematical model of UAV negatively influenced by exogenous disturbances is established. Following, an extended state/disturbance observer using a general second-order model is designed to approximate undesirable influences of perturbations on the UAVs dynamics. Finally, a nonlinear robust controller is constructed by an integration of the nominal backstepping technique with ESDO to enhance the performance of attitude and position control mode. Robust stability of the closed-loop disturbed system is obtained and guaranteed through the Lyapunov theorem without precise knowledge of the upper bound condition of perturbations. Lastly, a numerical simulation is carried out and compared with other previous controllers to demonstrate the great advantage and effectiveness of the proposed control method.

Giant hepatic angiomyolipoma presenting with severe anemia: A surgical case report and review of literature.

BACKGROUND: Angiomyolipoma (AML) is a solid benign neoplasm with mesenchymal features. The clinical signs and symptoms of hepatic angiomyolipoma are nonspecific, and treatment strategy is variable. PRESENTATION: A 35-years-old male patient has admitted to the hospital with symptoms of severe anemia. Abdominal multi-slice computed tomography (MSCT) and Gadoxetic acid (GA)-enhanced magnetic resonance imaging (MRI) revealed a heterogeneous 23 × 17 cm-in-sized tumor with heterogeneous enhancement and increased angiogenesis. Percutaneous hepatic biopsy was proceeded and in immunohistochemistry, tumor cells responded positively to the HMB-45, SMA, and Glutamine stains, the CD-34 stain was positive for blood vessels as well as Ki-67 sporadically positive, but the Heppar1, S-100, CK stains reacted negative. The final pathologic result was consistent with the primary hepatic angiomyolipoma. The final surgical management was extended right hepatectomy with ligation of the right hepatic artery (RHA) and vein (RHV), as well as the middle hepatic vein (MHV), one month after portal embolization as well as to enlarge the remnant liver volume. DISCUSSION: A hepatic angiomyolipoma (HAML) primary origin is relatively rare, the clinical manifestations are variable and non-specific. Histological examination and immunohistochemistry staining are considered as the gold standard for HAML diagnosis. HAML are commonly expressed benign behaviors, but HAML cases with malignant behaviors were reported in a cumulative incidence. Radical surgery must be still the most effective and major treatment approach. CONCLUSION: The present case being the first case with initial syndrome of severe anemia accounted in the English literature. Giant angiomyolipoma is composed of blood vessels and could lead to extensive internal tumoral hemorrhage. We here present a report of this case with had primary hepatic angiomyolipoma with clinical picture of severe anemia.

Serum pepsinogen: A potential non-invasive screening method for moderate and severe atrophic gastritis among an asian population.

Background: Serum pepsinogen has been approved and used widely as an effective biomarker in diagnosis of atrophic gastritis and gastric cancer; however, its validity and appropriate cut-off values vary among different populations. This study aimed to initially assess the diagnostic value of the serum pepsinogen in diagnosis of moderate and severe atrophic gastritis for Vietnamese population. Materials and methods: A cross-sectional study enrolled 273 participants from June 2008 to November 2019. All participants underwent a gastroscopy procedure and three tests including serum PG test, pathology test, and Hp-Igg Elisa test. The Kimura-Takemoto classification and OLGA system were used to classify the mild versus moderate-severe atrophic gastritis. Receiver Operating Characteristic curve was used to assess the value of PGI, PGII and PGR. Results: Based on Kimura-Takemoto classification, the AUC of PGI and PGR was 0.635 (p = 0.008, 95% CI 0.554-0.716) and 0.766 (p < 0.001, 95% CI 0.676-0.857) respectively. The best cut-off values were PGI ≤69.0 and PGR ≤4.6 (sensitivity: 73%, specificity: 83.9%, positive predictive value: 41.5%, negative predictive value: 95.2%, accuracy: 82.4%). According to the OLGA system, the AUC of PGI and PGR was 0.612 (p = 0.004, 95% CI 0.540-0.684) and 0.689 (p < 0.001, 95% CI 0.621-0.758) respectively. The best cut-off values were PGI ≤63.5 and PGR ≤5.2 (sensitivity: 49.4%, specificity: 82.1%, positive predictive value: 52.1%, negative predictive value: 80.5%, accuracy: 72.9%). Conclusions: The serum pepsinogen II and pepsinogen I/II ratio had reliable diagnostic value for screening of moderate and severe atrophic gastritis among Vietnamese population. Further research was recommended to focus on larger scale to improve the diagnostic yield and to continue finding the cut-off values for diagnosis of gastric cancer among Vietnamese population.

Churn prediction in telecommunication industry using kernel Support Vector Machines.

In this age of fierce competitions, customer retention is one of the most important tasks for many companies. Many previous works proposed models to predict customer churn based on various machine learning techniques. In this study, we proposed an advanced churn prediction model using kernel Support Vector Machines (SVM) algorithm for a telecom company. Baseline SVM models were initially built to find out the most suitable kernel types and will be used to make comparison with other approaches. Dimension reduction strategies such as Sequential Forward Selection (SFS) and Sequential Backward Selection (SBS) were applied to the dataset to find out the most important features. Furthermore, resampling techniques to deal with imbalanced data such as Synthetic Minority Oversampling Technique Tomek Link (SMOTE Tomek) and Synthetic Minority Oversampling Technique ENN (SMOTE ENN) were used on the dataset. Using the above-mentioned techniques, we have obtained better results compared to those obtained from previous works, we achieved an F1-score and accuracy of 99% and 98.9% respectively.

Pancreatic angiosarcoma with synchronous pancreatic ductal adenocarcinoma leading to hemosuccus pancreaticus: A surgical case report and review of literature.

Introduction: Angiosarcoma of pancreas is an extremely rare disease with a poor prognosis. The clinical signs and symptoms of pancreatic angiosarcoma are nonspecific, and it is occasionally diagnosed at an advanced stage. Pancreatic angiosarcoma and Pancreatic ductal adenocarcinoma in one patient was never ever known in English literature. Case presentation: A 56-year-old female was admitted with clinical and laboratory signs of gastrointestinal (GI) bleeding. Upper gastrointestinal endoscopy revealed bleeding from the ampulla of Vater. Besides, abdominal computed tomographic (CT) revealed a solid mass in the region of the pancreatic tail, which was considered the origin of bleeding. Distal pancreatectomy and splenectomy were performed because of persistent GI bleeding, and the final histological diagnosis of tumor in pancreatic tail was pancreatic ductal adenocarcinoma. After 30 days, she developed recurrent bleeding in ampulla and the abdominal CT-scan revealed a huge hematoma in omentum harem. We conducted transcatheter arterial embolization, but anemia continued to worsen. Therefore, pancreaticoduodenectomy was recommended to remove this mass, and based on postoperative histological findings, pancreatic angiosarcoma was diagnosed. After few days, laparotomy was indicated again because of persistent intra-abdominal bleeding. Despite all critical care and surgical therapeutic attempts, the patient died within two weeks after operation. Discussion: A pancreatic angiosarcomas primary origin is especially rare, with the present case being the tenth accounted in the English literature. Angiosarcomas is creating a disorganized mass of cells with extravasated blood that led to characteristics, extensive amounts of hemorrhage. The clinical manifestations of pancreatic angiosarcoma are variable, and immunohistochemistry staining is mandatory, with positive staining for vascular markers, which include CD31, CD34, von Willebrand factor (vWF), factor-VIII, Ulex europaeus agglutinin 1 (UEA-1), Friend leukemia integration 1 (Fli-1) and vascular endothelial growth factor receptor (VEGFER). Conclusion: We here present a report of an extremely rare case with had pancreatic angiosarcoma and synchronous pancreatic ductal adenocarcinoma with clinical picture of GI bleeding secondary to hemosuccus pancreaticus (HP).

Development of a low-cost colorimeter and its application for determination of environmental pollutants.

Herein, a novel colorimeter based on the Beer-Lambert law was designed for detection of environmental pollutants in water with a high precision, simple, and miniaturized device using a tetracycline-Eu3+ complex, cadmium reduction, diazotization, 1,10-phenanthroline, and periodate oxidation. The newly developed colorimeter could detect many environmental pollutants including tetracycline, nitrate, nitrite, Fe, and Mn, which were used to evaluate its performance. Simultaneously, a modified algorithm was applied to extend the linear response range. The colorimeter was comprised of an Red Green Blue Light Emitting Diode (RGB LED) light, focusing len, 3D printed stand for the cuvette, and light-sensitive photodiode detector. Microcontroller Arduino Uno processing technology was used to form a stable integrated structure. With the use of a novel algorithm, the device exhibited a wide linear response, ranging from 0-20, 0-17, 0-0.3, 0-1.75, and 0-15 mg/L for tetracycline, N-NO3-, N-NO2-, Fe, and Mn, respectively, and low limits of detection (0.88, 0.34, 0.031, 0.08, and 0.47 mg/L for tetracycline, N-NO3-, N-NO2-, Fe, and Mn, respectively). The advantages of high precision and low cost allow the novel design to be used for the detection of environmental pollutants.

Causes and Clinical Characteristics of Small Bowel Bleeding in Northern Vietnam.

Aim: Causes, clinical features, and diagnostic approaches for small bowel (SB) bleeding were analyzed to derive recommendations in dealing with this clinical condition. Methods: We included 54 patients undergoing surgical treatment for SB bleeding, from January 2009 to December 2019. Detailed clinical data, diagnosis procedures, and causes of bleeding were collected. Results: Among 54 cases with SB bleeding, the most common causes were tumors (64.8%), followed by angiopathy (14.8%), ulcers (9.3%), diverticula (5.6%), tuberculosis (3.7%), and enteritis (1.9%). Most tumors (32/35 cases, 91.4%) and vascular lesions (8/8 cases, 100%) were located in the jejunum. The incidence of tumors was higher in the older (30/41 cases, 73.1%) than that in patients younger than 40 years of age (5/13 cases, 38.5%, P < 0.01). Common initial findings were melena (68.5%) and hematochezia (31.5%). The overall diagnostic yield of computed tomographic enterography (CTE) was 57.4% (31/54 cases), with the figures for tumors, vascular lesions, and inflammatory lesions being 71.4% (25/35 cases), 62.5% (5/8 cases), and 12.5% (1/8 cases), respectively. Double-balloon enteroscopy (DBE) definitively identified SB bleeding sources in 16/22 (72.7%) patients. Conclusion: Tumors, angiopathy, ulcers, and diverticula were the most common causes of SB bleeding in Northern Vietnamese population. CTE has a high detection rate for tumors in patients with SB bleeding. CTE as a triage tool may identify patients before double-balloon enteroscopy because of the high prevalence of SB tumors.

Validation of a Highly Sensitive qPCR Assay for the Detection of Plasma Cell-Free Epstein-Barr Virus DNA in Nasopharyngeal Carcinoma Diagnosis.

Quantification of plasma cell-free Epstein Barr virus DNA (cf EBV DNA) has been suggested as a promising liquid biopsy assay for screening and early detection of nasopharyngeal carcinoma (NPC). However, the diagnostic value of this assay is currently not known in the population of Vietnam, one of the countries which contributed the most to the NPC cases. Herein, we have reported a highly sensitive quantitative polymerase chain reaction (qPCR)-based assay targeting cf EBV DNA for the detection of NPC. A standard curve with linear regression, R 2 = 0.9961 (range: 25-150 000 copies/mL) and a detection limit of 25 copies/mL were obtained using an EBV standard panel provided by the Chinese University of Hong Kong. The clinical performance of this assay was assessed using plasma samples obtained from 261 Vietnamese individuals. The optimized qPCR assay detected cf EBV DNA in plasma with a sensitivity of 97.4% and a specificity of 98.2%. The absolute quantitative results of pretreatment cf EBV DNA and patient overall clinical stages were statistically correlated (P < .05). In summary, the remarkably high sensitivity and specificity of our optimized qPCR assay strongly supports the wide use of cf EBV DNA quantification as a routine noninvasive method in early diagnosis and management of patients with NPC.

Surface-Modified Carbon Nanotubes for Enhanced Ammonia Gas Sensitivity at Room Temperature.

By electron beam evaporation, noble metals (Au, Co, Pt, and Ag) with 2 and 4 nm nominal thicknesses were coated onto multi-walled carbon nanotube layers. The metals were in the form of nanoparticles mounted onto the side walls of carbon nanotubes (CNTs) to create a metal/CNT junction. The CNTs were directly grown on patterned Pt-electrode alumina substrates through chemical vapor deposition to produce a resistivity-based ammonia gas sensor. The metallic surface-modified CNT-based sensors were found sensitive to NH3 gas at room temperature. Compared with pristine CNT sensor, the response of Au/CNTs sensor increased slightly, whereas the responses of the Pt/CNTs, Co/CNTs, and Ag/CNTs increased by two, three, and more than four times, respectively.