Diagnostic value of vietnamese smell identification test in Parkinson's disease.

INTRODUCTION: The Vietnamese Smell Identification Test (VSIT) has been validated in determining olfactory dysfunction in the Vietnamese population; however, its value in diagnosing Parkinson's disease (PD) has not been established. METHODS: This case-control study was conducted at University Medical Center HCMC, Ho Chi Minh City, Vietnam. The study sample included non-demented PD patients and healthy controls (HC) who were gender- and age-matched. All participants were evaluated for odor identification ability using the VSIT and the Brief Smell Identification Test (BSIT). RESULTS: A total of 218 HCs and 218 PD patients participated in the study. The median VSIT and BSIT scores were significantly different between PD and HC groups (VSIT, 5 (3) vs. 9 (2), P < 0.0001; BSIT, 6 (3) vs 8 (2), P < 0.0001). Using the cut-off of <8 for correct answers out of 12 odorants, the VSIT had higher sensitivity (84.4%) and specificity (86.2%) than those of the BSIT (sensitivity of 81.7% and specificity of 69.3%) for the diagnosis of PD. The area under the curve (AUC) value was greater for the VSIT than for the BSIT (0.909 vs 0.818). The smell identification scores were not significantly correlated with disease duration, disease severity, or LEDD (all p > 0.05). CONCLUSION: The VSIT can be a valuable ancillary tool for supporting the diagnosis of PD in Vietnam. Olfactory dysfunction in PD was unrelated to the disease duration and severity. The VSIT can be applied to improve the accuracy of clinical PD diagnosis.

Pain is common in early onset Parkinson's disease and pain severity is associated with age and worsening of motor and non-motor symptoms.

The consequences of pain in early onset Parkinson's disease (EOPD) remain under appreciated even though pain may exert an increasingly negative impact on patient quality of life as motor and non-motor symptoms worsen. In this prospective study, we investigate the prevalence and severity of pain in 135 Vietnamese patients with EOPD from three medical centers using the King's PD Pain Scale (KPPS), the Mini Mental Status Exam (MMSE), the Unified Parkinson's Disease Rating Scale (UPDRS) and the Non-Motor Symptoms Scale (NMSS). Pain was reported by 79.3%. The most common subtype of pain was musculoskeletal (70.1%), followed by nocturnal (43.9%), radicular (43.0%), chronic (42.1%), fluctuation-related (34.6%) and orofacial pain (16.8%). Most patients (74.8%) experienced more than one pain subtype. Fluctuation-related pain and orofacial pain were significantly more prevalent among patients with higher Hoehn & Yahr (H&Y) stages (3-5) versus lower H&Y stages (1-2). Pain subtype and severity were not significantly related to gender or age of PD onset. Patients with H&Y stages 3-5 had statistically significantly higher KPPS scores for fluctuation-related pain (p = 0.018) and radicular pain (p = 0.026). Independent associations were found between pain severity and age (p = 0.028), depression severity (p = 0.018), perceptual problems/hallucinations (p = 0.033) and sexual function (p = 0.024). Patients with depression and higher H&Y stages (3-5) had statistically significantly higher mean KPPS scores versus patients without depression and at lower H&Y stages (1-2). Pain may be more common and severe in EOPD patients than previously appreciated. Older age, depression, perceptual problems/hallucinations and sexual dysfunction were independently associated with higher pain severity.

Normative data for the Vietnamese smell identification test.

Introduction: The 12-item Vietnamese smell identification test (VSIT) has been developed to evaluate the olfactory function of the Vietnamese population. This study aimed to investigate the normative value of the VSIT in different age groups and sexes. Methods: This cross-sectional study was conducted at Ho Chi Minh University Medical Center, Vietnam. All participants were evaluated for odor identification ability using the VSIT. We included healthy participants aged 18 years or older with no history of olfactory disturbances. Results: A total of 391 healthy volunteers were recruited with a mean age of 45.80 years (SD: 17.62; range: 18-86; female: 63.4 %). The tenth percentile of scores on the 0-12 VSIT scale was 8.3 in participants aged 18-29 years, 9.0 in 30-39 years, 8.0 in 40-49 years, 7.8 in 50-59 years, 7.9 in 60-69 years and 6.0 in over 70 years. Young adults (18-39 years old) had better olfactory identification ability than older adults (over 50 years), p < 0.001. There was a significant main effect of sex on VSIT score (p = 0.02), suggesting that females outperformed males. Sensitivity to 8 odors were negatively correlated with age: lemon, garlic, banana, coffee, mango, guava, apple and watermelon (p < 0.05 in all cases) whereas four odors were age-independent including orange, fish sauce, soy sauce, and fish. Conclusion: Normative data provide guidance for assessing individual olfactory function. However, there were significant sex and age effects on olfactory identification scores on the VSIT. Therefore, future studies should be conducted to better adjust for those confounders mentioned above.

A comparison of effectiveness between Posisep and Merocel nasal packing after endoscopic sinus surgery: Findings from a randomized, double-blinded, controlled trial.

BACKGROUND: The effectiveness of nonabsorbable and biodegradable nasal packing is still controversial, and the choice of nasal packing type can alter the outcome of endoscopic sinus surgery. This study compared the effectiveness of Posisep and Merocel as nasal packing materials with regard to hemostasis, adhesion, wound healing, patient's satisfaction and health-related quality of life after endoscopic sinus surgery (ESS). METHODS: A prospective, randomized, double-blinded, controlled trial was conducted in patients with chronic rhinosinusitis refractory undergoing symmetrical bilateral ESS. At the completion of surgery, a nasal packing (either Merocel or Posisep) was randomly chosen and placed into the middle meatus of each nasal cavity. All patients were scheduled for follow-up visits at 24 hours, 5 days, 3 weeks, and 5 weeks days after surgery. Health-related quality of life was measured using the Sino-Nasal Outcome Test (SNOT-22). The overall inflammatory burden of chronic rhinosinusitis was measured by the Lund-Mackay postoperative endoscopic score (LMES). RESULTS: Among 62 patients included in data analysis (n = 31 for each group), the mean age was 42.4 years and 54.8% were females. Patients with Posisep after ESS had more improvement and better symptoms measured through SNOT-22 and LMES at 24 hours, 5 days, and 3 weeks than those with Merocel after ESS. While some aspects measured by LMES such as discharge and scarring were still better until 5 weeks after surgery, all symptoms measured by SNOT-22 were similar between the 2 groups 5 weeks after surgery. CONCLUSION: Posisep containing chitosan provided patients with a better quality of life throughout the early recovery period compared with Merocel. Although more studies are needed, our findings support the use of Posisep after ESS.

Development and validation of the Vietnamese smell identification test.

BACKGROUND: Correct olfactory identification requires familiarity with the odor stimuli and is culturally dependent. Existing smell identification tests (SIT) are not culturally specific and may not be reliable in detecting hyposmia in all populations. This study aimed to develop a smell identification test suitable for Vietnamese patients (VSIT). METHODS: The study included 4 phases: 1) survey-based evaluation of the familiarity of 68 odors to identify 18 odors for subsequent testing (N = 1050); 2) smell identification test of 18 odors in healthy patients (N = 50) to determine which 12 should be included in the VSIT; 3) comparison of VSIT scores on 12 odors in patients with hyposmia (N = 60; Brief smell identification test (BSIT) score <8 and those with normosmia (N = 120; BSIT score ≥8) to establish the validity of the newly developed test; and 4) retest of the VSIT in 60 normosmic patients from phase 3 (N = 60) to determine test-retest reliability. RESULTS: As expected, the mean (SD) VSIT score was significantly higher in the healthy participants than in the hyposmic patients [10.28 (1.34) vs 4.57 (1.76); P < 0.001]. Using a cut-off score at 8, the sensitivity and specificity of the instrument in detecting hyposmia were 93.3% and 97.5% respectively. The test-retest reliability using the intra-class correlation coefficient was at 0.72 (P < 0.001). CONCLUSION: The Vietnamese Smell Identification Test (VSIT) demonstrated favorable validity and reliability and will allow for assessment of olfactory function in Vietnamese patients.

Accuracy of Subthalamic Nucleus Electrode Implantation in Deep Brain Stimulation Surgery for Parkinson's Disease Treatment and Affecting Factors: Outcomes at Two Centers in Vietnam.

BACKGROUND: Deep brain stimulation (DBS) surgery for Parkinson's Disease (PD) has become more and more popular in Vietnam. However, the accuracy of implantation and affecting factors are under investigation. The objective of this study is to evaluate the accuracy of the subthalamic nucleus (STN)-DBS electrode implantation technique for treatment PD at Nguyen Tri Phuong Hospital and University Medical Center. To investigate factors related to accuracy. METHODS: We carried out a retrospective analysis of 58 patients with advanced PD who underwent STN-DBS surgery at Nguyen Tri Phuong Hospital and University Medical Center in Ho Chi Minh City, Viet Nam between June 2014 and July 2021 (115 leads total). All patients underwent the procedure with standard frame-based techniques under local anesthesia with microelectrode recording and macrostimuation test. RESULTS: Twenty-six female (44.8%) and thirty-two male (55.2%) patients with a mean age of 60.4 ± 8.3 years old (40-76 years) were included. Of total of 115 electrodes implanted, the mean target error (ΔT), radial error (ΔR), angle error (Δθ) were 1.94 ± 0.73 mm; 1.16 ± 0.69 mm; 2.22 ± 4.24 degrees, respectively. Vector error on each coordinate axis ΔX, ΔY, ΔZ were -0.35 ± 1.02 mm, +0.99 ± 0.82 mm, +0.73 ± 0.99 mm, respectively. There was a statistically significant correlation between subdural air volume, cortical shift, intracranial electrode bending, and accuracy. CONCLUSIONS: The current STN-DBS electrode implantation technique applied in our centers was quite accurate with acceptable error. More clinical trials are necessary to directly compare affecting factors to the accuracy of electrode implantation.

Clinical and genetic analysis of Vietnamese patients diagnosed with early-onset Parkinson's disease.

BACKGROUND: Genetic factors play a crucial role in the pathogenesis of Parkinson's disease (PD). However, no comprehensive study has described genetic alterations in Vietnamese patients diagnosed with PD. This study aimed to identify genetic causes and their association with clinical phenotypes in a Vietnamese PD cohort. METHODS: A total of 83 patients with early-onset PD (disease onset before the age of 50) were recruited for genetic analysis using a combination of multiplex ligation-dependent probe amplification and next-generation sequencing for a panel of 20 PD-associated genes. RESULTS: It was found that 37 out of 83 patients carried genetic alterations, with 24 pathogenic/likely pathogenic/risk variants and 25 variants of uncertain significance. The pathogenic/likely pathogenic/risk variants were mostly detected in LRRK2, PRKN, and GBA, while the variants of uncertain significance were identified in 12 different genes that were studied. The most common genetic alteration was LRRK2 c.4883G>C (p.Arg1628Pro), and patients with PD carrying this variant were found to have a distinct phenotype. Participants carrying pathogenic/likely pathogenic/risk variants had a significantly higher rate of a family history of PD. CONCLUSION: These results provide a further understanding of genetic alterations associated with PD in a South-East Asian population.

Plasma cell-free RNA profiling of Vietnamese Alzheimer's patients reveals a linkage with chronic inflammation and apoptosis: a pilot study.

Introduction: Circulating cell-free RNA (cfRNA) is a potential hallmark for early diagnosis of Alzheimer's Disease (AD) as it construes the genetic expression level, giving insights into the pathological progress from the outset. Profiles of cfRNA in Caucasian AD patients have been investigated thoroughly, yet there was no report exploring cfRNAs in the ASEAN groups. This study examined the gap, expecting to support the development of point-of-care AD diagnosis. Methods: cfRNA profiles were characterized from 20 Vietnamese plasma samples (10 probable AD and 10 age-matched controls). RNA reads were subjected to differential expression (DE) analysis. Weighted gene correlation network analysis (WGCNA) was performed to identify gene modules that were significantly co-expressed. These modules' expression profiles were then correlated with AD status to identify relevant modules. Genes with the highest intramodular connectivity (module membership) were selected as hub genes. Transcript counts of differentially expressed genes were correlated with key AD measures-MMSE and MTA scores-to identify potential biomarkers. Results: 136 genes were identified as significant AD hallmarks (p < 0.05), with 52 downregulated and 84 upregulated in the AD cohort. 45.6% of these genes are highly expressed in the hippocampus, cerebellum, and cerebral cortex. Notably, all markers related to chronic inflammation were upregulated, and there was a significant shift in all apoptotic markers. Three co-expressed modules were found to be significantly correlated with Alzheimer's status (p < 0.05; R2> 0.5). Functional enrichment analysis on these modules reveals an association with focal adhesion, nucleocytoplasmic transport, and metal ion response leading to apoptosis, suggesting the potential participation of these pathways in AD pathology. 47 significant hub genes were found to be differentially expressed genes with the highest connectivity. Six significant hub genes (CREB1, YTHDC1, IL1RL1, PHACTR2, ANKRD36B, RNF213) were found to be significantly correlated with MTA and MMSE scores. Other significant transcripts (XRN1, UBB, CHP1, THBS1, S100A9) were found to be involved in inflammation and neuronal death. Overall, we have identified candidate transcripts in plasma cf-RNA that are differentially expressed and are implicated in inflammation and apoptosis, which can jumpstart further investigations into applying cf-RNA as an AD biomarker in Vietnam and ASEAN countries.

Myeloencephalitis as the only presentation of Omicron SARS-CoV-2 infection.

SARS-CoV-2 is now a major global health issue and manifests mainly as a respiratory disorder. Several other complications involving hypercoagulability, cardiovascular system and central nervous system have been described in the literature. Among these atypical presentations, encephalopathy associated with SARS-CoV-2 is a rare entity with heterogenous clinical and radiological findings. The direct presence of SARS-CoV-2 in cerebrospinal fluid (CSF) was rarely found in encephalopathy patients with acute SARS-Cov-2 infection.Here, we report a case of myeloencephalitis with positive real-time PCR for SARS-CoV-2 in CSF in a young woman presenting exclusively with neurological symptoms. Other differential diagnosis were extensively pursued by a comprehensive aetiological workup. To our knowledge, this is the first case report in the Omicron era. In the context of recent global explosion of SARS-Cov-2 infections, clinicians should consider this pathogen among other possible neurotropic agents and be familiar with its radiological and clinical presentations.

Laccase-mimicking Mn-Cu hybrid nanoflowers for paper-based visual detection of phenolic neurotransmitters and rapid degradation of dyes.

BACKGROUND: Laccase-based biosensors are efficient for detecting phenolic compounds. However, the instability and high cost of laccases have hindered their practical utilization. RESULTS: In this study, we developed hierarchical manganese dioxide-copper phosphate hybrid nanoflowers (H-Mn-Cu NFs) as excellent laccase-mimicking nanozymes. To synthesize the H-Mn-Cu NFs, manganese dioxide nanoflowers (MnO2 NFs) were first synthesized by rapidly reducing potassium permanganate using citric acid. The MnO2 NFs were then functionalized with amine groups, followed by incubation with copper sulfate for three days at room temperature to drive the coordination interaction between the amine moieties and copper ions and to induce anisotropic growth of the petals composed of copper phosphate crystals, consequently yielding H-Mn-Cu NFs. Compared with those of free laccase, at the same mass concentration, H-Mn-Cu NFs exhibited lower Km (~ 85%) and considerably higher Vmax (~ 400%), as well as significantly enhanced stability in the ranges of pH, temperature, ionic strength, and incubation periods evaluated. H-Mn-Cu NFs also catalyzed the decolorization of diverse dyes considerably faster than the free laccase. Based on these advantageous features, a paper microfluidic device incorporating H-Mn-Cu NFs was constructed for the convenient visual detection of phenolic neurotransmitters, including dopamine and epinephrine. The device enabled rapid and sensitive quantification of target neurotransmitters using an image acquired using a smartphone. CONCLUSIONS: These results clearly show that H-Mn-Cu NFs could be potential candidates to replace natural laccases for a wide range of applications in biosensing, environmental protection, and biotechnology.

Community-based Interventions to Prevent Dental Caries among Kindergarten Children in Vietnam: A 12-month Study of Field Trial.

AIM: To investigate the status of dental caries and assess the effectiveness of dental caries prevention interventions in children from 3 to 5-year-old in Hue City, Vietnam. MATERIALS AND METHODS: The subjects were 464 children and their direct caregivers at some kindergartens in Hue City from June 2020 to October 2021. The study included two consecutive phases: the first one was a cross-sectional study to identify the rate of dental caries and related factors in the studied kindergartens, and phase 2 was a controlled comparative interventional study for a period of 12 months. RESULTS: The mean of decayed, missing, filled, and DMFT index was 8.25, 0.09, 0.48, and 8.82, respectively, with no statistically significant difference in these figures between the living areas. The multivariable logistic regression model revealed some factors related to dental caries, including age, frequency of toothbrushing per day, parent-assisted toothbrushing, and eating and drinking sweets. Results showed the effectiveness of a community-based intervention for preventing dental caries, gingivitis, and plaque in the intervention group, compared to the control group. CONCLUSION: The rate of dental caries among Vietnamese children was remarkably high. A comprehensive intervention to prevent early childhood dental caries was effective and might be considered a necessary program in healthcare prophylaxis. CLINICAL SIGNIFICANCE: This intervention was consistent with the guidelines of WHO and based on evidences of related factors of dental caries identified in a previous cross-sectional study.

Adherence to COVID-19 Preventive Measures among Dental Care Workers in Vietnam: An Online Cross-Sectional Survey.

An online cross-sectional survey using a "snowball" sampling method was carried out to assess the adherence to COVID-19 preventive measures among dental care workers (DCWs) during the pandemic. Six questions concerning the COVID-19 preventive guidelines issued by the Vietnam Ministry of Health were used to evaluate DCWs' adherence to preventive measures at dental care clinics. The quality of life of DCWs was assessed using the WHO-5 questionnaire and was defined as low if the total score was less than 13 points. Factors relating to adherence to COVID-19 prevention measures of DCWs were determined by multivariate linear regression analysis. In total, 514 DCWs completed the questionnaire. A total of 37% DCWs rated their quality of life as low. Regression analysis suggested that older age, a better quality of life, living in an urban area, and training on COVID-19 prevention were associated with better adherence to COVID-19 preventive measures, while being a dentist and lack of personal protective equipment was associated with less adherence to COVID-19 preventive measures. The pandemic had a significant negative impact on the physical and mental health of DCWs. Therefore, specific national guidelines for the prevention and control of the spread of COVID-19 in dental facilities should be issued.

Assessing the impact of green fiscal policies and energy poverty on energy efficiency.

This article estimates the ties between green fiscal policies and energy efficiency in COVID-19 era. For this purpose, data envelopment analysis (DEA) approach is considered and applied. The study findings show that green fiscal policies, such as public supports and tax rebates, have significant role in reducing energy poverty of different international countries by advancing energy efficiency. Therefore, a panel data ranging from 2010 to 2020 is used. Our findings indicate that the aggregate degree of green fiscal policies help to decline energy poverty. Renewable energy companies had larger series of net fiscal competence and size efficiency, and their levels of energy efficiency were greater than 0.457%, with the 16% effect of current public supports and 11% effect of taxation rebates supported to diminish energy poverty with 29.7% in different international economies. This is a positive effect by green fiscal policies. The study also presented policy implications suggesting effectively implementing green fiscal policies for more efficient carbon reduction and making climate change supportive for peoples in post COVID-19 period.

Profile of aeroallergen sensitizations in allergic patients living in southern Vietnam.

Background: Climatic and geographical characteristics may alter the plant distribution and thereby the patterns of allergens. Objective: To evaluate the profile of allergen sensitization in patients in southern Vietnam and its association with allergic diseases. Methods: We collected data of 423 patients who visited the Unit of Allergy and Clinical Immunology, University Medical Center, Vietnam from 2014 to 2021, from their medical records. Patients underwent skin prick tests to the 12 most common aeroallergens. Clinical evaluation and diagnosis of allergic diseases was done in consert with their allergen sensitization status. Results: Mites and cockroach were the most prevalent sensitizing allergens, with the sensitization prevalences as followed: Dermatophagoides farinae (Df) (59.8%), Dermatophagoides pteronyssinus (Dp) (50.4%), Blomica tropicalis (Bt) (49.6%), storage mites mix (10.4%), and cockroach (10.2%). Sensitization to Df was more predominant in males than in females (66% vs 54.1%). Dp-sensitized patients were younger than non-sensitized patients (29.01 ± 13.60 vs. 32.17 ± 14.89) whereas storage mites-sensitized patients were older than the non-sensitized groups (36.25 ± 13.53 vs. 28.76 ± 13.39) (p < 0.05 for all). A considerable proportion of patients with urticaria, allergic rhinitis, and atopic dermatitis were sensitized to mites. Polysensitization to different species of house dust mites (Dp, Df) and storage mites (Bt) was prevalent among patients sensitized to any kind of mites. Conclusions: Among people living in southern Vietnam, HDM mites, and cockroach were the predominant allergens. Further studies on the factors regulating the association between allergen sensitization with allergic diseases and polysensitization are crucial.

The effect of Non-Motor symptoms on Health-Related quality of life in patients with young onset Parkinson's Disease: A single center Vietnamese Cross-Sectional study.

BACKGROUND: Young onset Parkinson's disease (YOPD) is a distinct entity from typical late onset Parkinson's disease (LOPD). The influene of non-motor features on the health - related quality of life (HRQoL) in LOPD has been previously reported, but little is known about the impact of non-motor features in YOPD. OBJECTIVE: The aim of this study was to explore the relationship between non-motor burden and HRQoL in patients with YOPD. METHODS: This was an observational, cross-sectional study in patients with a PD, whose age at disease onset ranged from 21 to 40 years (YOPD). Participants were assessed with the MDS Unified Parkinson's Disease Rating Scale (MDS-UPDRS), Non-Motor Symptoms Scale (NMSS) and the 39-item Parkinson's Disease Questionnaire (PDQ-39; range 0-100). Spearman's rank test was used to identify correlations between NMSS domains and several dimension of HRQoL. Stepwise multiple linear regression analysis was performed to identify the independent predictors of HRQoL as measured by PDQ-39 summary index. RESULTS: 89 patients with YOPD mean (SD) age = 42.15 (5.84) participated. Patients reported 10.17 (4.74) non-motor symptoms, the most common (75%) and severe (median = 3) of which was was fatigue (IQR = 7). The most frequently reported and severely affected NMSS domain was sleep/fatigue (89.9%, median = 8; IQR = 13) followed by mood/cognition (83.1%, median = 6; IQR = 18) and attention/memory (82%, median = 5; IQR = 8). The mean (SD) summary index of PDQ-39 was 32.89 (16.8). The means (SD) of each PDQ-39 dimensions were: mobility 37.33 (21.96), ADL 42.93 (25.33), emotional well-being 39.77 (25.47), stigma 38.19 (28.44), social support 19.03 (22.89), cognition 29.59 (20.63), communication 26.96 (23.57), and bodily discomfort 29.96 (23.19). With the exception of gastrointestinal tract and sexual function, all other NMSS domain scores were correlated with the PDQ-39 summary index. The multivariate model revealed that three NMSS domains including sleep/fatigue, mood/cognition and attention/memory accompanied with UPDRS part III were independent predictors of HRQoL as measured by PDQ-39SI. CONCLUSIONS: Non-motor symptoms pertaining to sleep disturbances/fatigue, mood/cognition and attention/memory negatively impact HRQoL in patients with YOPD.

A step toward reducing air pollution in top Asian economies: The role of green energy, eco-innovation, and environmental taxes.

Environmental degradation is significantly studied both in the past and the current literature; however, steps towards reducing the environmental pollution in carbon emission and haze pollution like PM2.5 are not under rational attention. This study tries to cover this gap while considering the carbon emission and PM2.5 through observing the role of renewable energy, non-renewable energy, environmental taxes, and ecological innovation for the top Asian economies from 1990 to 2017. For analysis purposes, this research considers cross-sectional dependence analysis, unit root test with and without structural break (Pesaran, 2007), slope heterogeneity analysis, Westerlund and Edgerton (2008) panel cointegration analysis, Banerjee and Carrion-i-Silvestre (2017) cointegration analysis, long-short run CS-ARDL results, as well as AMG and CCEMG for robustness check. The empirical evidence in both the short- and long-run has confirmed the negative and significant effect of renewable energy sources, ecological innovation, and environmental taxes on carbon emissions and PM2.5. Whereas, non-renewable energy sources are causing environmental degradation in the targeted economies. Finally, various policy implications related to carbon emission and haze pollution like PM2.5 are also provided to control their harmful effect on the natural environment.

DNA-copper hybrid nanoflowers as efficient laccase mimics for colorimetric detection of phenolic compounds in paper microfluidic devices.

Laccases are important multicopper oxidases that are involved in many biotechnological processes; however, they suffer from poor stability as well as high cost for production/purification. Herein, we found that DNA-copper hybrid nanoflowers, prepared via simple self-assembly of DNA and copper ions, exhibit an intrinsic laccase-mimicking activity, which is significantly higher than that of control materials formed in the absence of DNA. Upon testing all four nucleobases, we found that hybrid nanoflowers composed of guanine-rich ssDNA and copper phosphate (GNFs) showed the highest catalytic activity, presumably due to the affirmative coordination between guanine and copper ions. At the same mass concentration, GNFs had similar Km but 3.5-fold higher Vmax compared with those of free laccase, and furthermore, they exhibited significantly-enhanced stability in ranges of pH, temperature, ionic strength, and incubation period of time. Based on these advantageous features, GNFs were applied to paper microfluidic devices for colorimetric detection of diverse phenolic compounds such as dopamine, catechol, and hydroquinone. In the presence of phenolic compounds, GNFs catalyzed their oxidation to react with 4-aminoantipyrine for producing a colored adduct, which was conveniently quantified from an image acquired using a conventional smartphone with ImageJ software. Besides, GNFs successfully catalyzed the decolorization of neutral red dye much faster than free laccase. This work will facilitate the development of nanoflower-type nanozymes for a wide range of applications in biosensors and bioremediation.

Impact of School-Based Oral Health Education on Vietnamese Adolescents: A 6-Month Study.

We have evaluated the impact of a school-based intervention on oral health knowledge, behaviours, and oral health status of adolescents in Vietnam. This 6-month study included 462 adolescents aged 12 years from four selected schools in Hue City, Vietnam. The intervention group received a 15-min lecture by a dentist and hands-on session on mouth observation and toothbrushing skills. The control group did not engage in any educational activities during the follow-up period. Data were collected at baseline and 6 months through a survey questionnaire and clinical examination. The Debris Index was used for dental plaque; the Papillary, Marginal, Attached gingiva index for gingivitis; and the Decayed, Missing, and Filled Teeth index (World Health Organization modification) for dental caries. Difference-in-difference analysis was used to compare changes between the groups. After 6 months, the control tended to show decreased toothbrushing frequency and increased dental plaque accumulation. The participants in the intervention group showed improved oral health knowledge (p < 0.01), behavior (p < 0.05), and hygiene (p < 0.001) compared to the control group. However, the intervention did not improve dental caries and gingivitis. A single school-based oral health education program can help adolescents improve oral health knowledge and prevent the deterioration of short-term oral health behavior and hygiene.

A Convenient Colorimetric Bacteria Detection Method Utilizing Chitosan-Coated Magnetic Nanoparticles.

An effective novel strategy to detect bacteria is promising because it may improve human health by allowing early diagnosis and timely treatment of bacterial infections. Here, we report a simple, reliable, and economical colorimetric assay using the peroxidase-like activity of chitosan-coated iron oxide magnetic nanoparticles (CS-MNPs). When CS-MNPs are incubated with a sample containing bacterial cells such as the gram-negative Escherichia coli or the gram-positive Staphylococcus aureus, the negatively-charged bacterial membrane interacts with positively-charged chitosan on the surface of CS-MNPs, thus resulting in significant reduction of their peroxidase-like activity presumably by a hindrance in the accessibility of the negatively charged substrate, 2-2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) to the positively-charged CS-MNPs. This simple colorimetric strategy allowed the rapid detection of bacterial cells down to 104 CFU mL-1 by the naked eye and 102 CFU mL-1 by spectrophotometry within 10 min. Based on the results, we anticipate that the CS-MNPs-based assay has great potential for the on-site diagnosis of bacterial infections in facility-limited or point-of-care testing (POCT) environments.