Highly stretchable,mechanically stable,and weavable reduced graphene oxide yarn with high NO2 sensitivity for wearable gas sensors

Stretchable gas sensors are important components of wearable electronic devices used for human safety and healthcare applications. However, the current low stretchability and poor stability of the materials limit their use. Here, we report a highly stretchable, stable, and sensitive NO₂ gas sensor composed of reduced graphene oxide (RGO) sheets and highly elastic commercial yarns. To achieve high stretchability and good stability, the RGO sensors were fabricated using a pre-strain strategy (strain-release assembly). The fabricated stretchable RGO gas sensors showed high NO₂ sensitivity (55% at 5.0 ppm) under 200% strain and outstanding mechanical stability (even up to 5000 cycles at 400% applied strain), making them ideal for wearable electronic applications. In addition, our elastic graphene gas sensors can also be woven into fabrics and clothes for the creation of smart textiles. Finally, we successfully fabricated wearable gas-sensing wrist-bands from superelastic graphene yarns and stretchable knits to demonstrate a wearable electronic device.

Highly stretchable, mechanically stable and weavable RGO elastic electronic yarns were developed using dip-coating with pre-straining. We demonstrate wearable gas sensors that can be worn on the wrist.     

Blood-based immunoassay of tau proteins for early diagnosis of Alzheimer's disease using surface plasmon resonance fiber sensors

We present the immunoassay of tau proteins (total tau and phosphorylated tau) in human sera using surface plasmon resonance (SPR) fiber sensors. This assay aimed at harvesting the advantages of using both SPR fiber sensors and a blood-based assay to demonstrate label-free point-of-care-testing (POCT) patient-friendly assay in a compact format for the early diagnosis of Alzheimer''s disease (AD). For conducting the assay, we used human sera of 40 subjects divided into halves, which were grouped into AD patients and control groups according to a number of neuropsychological tests. We found that on an average, the concentrations of both total tau and phosphorylated tau proteins (all known to be higher in cerebrospinal fluid (CSF) and the brain) turned out to be higher in human sera of AD patients than in controls. The limits of detection of total tau and phosphorylated tau proteins were 2.4 pg mL⁻¹ and 1.6 pg mL⁻¹, respectively. In particular, it was found that the AD group exhibited average concentration of total tau proteins 6-fold higher than the control group, while concentration of phosphorylated tau proteins was 3-fold higher than that of the control. We can attribute this inhomogeneity between both types of tau proteins (in terms of increase of control-to-AD in average concentration) to un-phosphorylated tau proteins being more likely to be produced in blood than phosphorylated tau proteins, which possibly is one of the potential key elements playing an important role in AD progress.

Blood-based early diagnosis of Alzheimer''s disease using a plasmonic fiber sensor that detects immunoreaction of tau proteins.     

Characterization of SCCA-IgM as a biomarker of liver disease in an Asian cohort of patients

Viral hepatitis infection is a major global issue and a leading cause of liver disease and associated deaths. Over time, patients infected with hepatitis B (HBV) or C virus (HCV) develop cirrhosis and, eventually, hepatocellular carcinoma (HCC). For this reason, they need to be constantly monitored. Current Asian guidelines recommend the determination of serum alpha-fetoprotein (AFP) together with liver ultrasounds every six months to detect HCC nodules. However, both methods have several limitations, and other biomarkers have been studied for monitoring cirrhosis, including SCCA-IgM, an immune-complex formed by Squamous Cell Carcinoma Antigen and IgM. To date, SCCA-IgM has been validated as a novel biomarker for liver diseases only in European populations. The aim of our study was to analyze SCCA-IgM as a biomarker to monitor cirrhosis evolution in an Asian cohort of patients and to compare its performance to that of AFP. We analyzed the concentration of AFP and SCCA-IgM in serum samples obtained from a group of Asian adult patients with cirrhosis or HCC and a control group of patients admitted for gastrointestinal disorders. In untreated patients and similarly to AFP, SCCA-IgM levels were significantly higher in patients with cirrhosis compared to those with HCC. In addition, SCCA-IgM, but not AFP serological levels, were significantly lower in HCC patients who were treated with surgical resection compared to those who received a different therapy.     

Establishing smoke-free hospitals in Vietnam: A pilot project

In Vietnam, a pilot ‘smoke-free hospital’ model was implemented in nine hospitals in 2009–2010 to supply lessons learned that would facilitate a replication of this model elsewhere. This study aimed to assess smoking patterns among health professionals and to detect levels of second-hand smoke (SHS) exposure within hospital premises before and after the ‘smoke-free hospital’ model implementation. A pre- and post-intervention cross-sectional study was conducted in nine purposively selected hospitals. Air nicotine levels were measured using passive nicotine monitors; smoking evidence was collected through on-site observations; and smoking patterns were assessed through interviews with health workers. Despite the ‘smoke-free hospital’ intervention, smoking continued among health-care workers who were former smokers. Specifically, self-reported smoking prevalence significantly decreased post-intervention, but the number of daily cigarettes smoked at workplaces among male health workers remained unchanged. Post-intervention, smoking was more likely to take place outside buildings and cafeterias. However, air nicotine levels in the doctors' lounges and in emergency departments did not change post-intervention. Air nicotine levels at other sites decreased minimally. Tailored tobacco cessation programmes, targeting current smokers and mechanisms to enforce non-smoking, should be established to meet requirements of Vietnam's comprehensive National Tobacco Control Law effective in May 2013.     

Factors associated with HIV testing among male motorbike taxi drivers in urban Vietnam

Using the Attitude-Skills-Knowledge (ASK) model, this study examined the prevalence of, and factors associated with, human immunodeficiency virus (HIV) testing among male motorbike taxi drivers (MMTDs). In a cross-sectional design, using quantitative approaches, 291 MMTDs were recruited from 135 sites across 13 districts in Hanoi, Vietnam, for a face-to-face interview. Applying the ASK model modified as a central theory, logistic regression was used to identify determinants of HIV testing. Although many MMTDs engaged in multiple risk behaviours for HIV, only 20.6% had been tested for HIV during the past 12 months. The tested model included one factor of the ASK model, HIV prevention knowledge (adjusted odds ratio [AOR] = 4.76; 95% confidence interval [CI] = 2.12–10.7) and five additional factors: being married (AOR = 3.13; 95% CI = 1.25–4.78), preferring sex with men or with both men and women (AOR = 8.72; 95% CI = 1.48–51.5), having lower number of lifetime sex partners (AOR = 0.66; 95% CI = 0.49–0.88), higher number of past year sex partners (AOR = 2.97: 95% CI = 1.21–7.31) and discussing condom use when having sex with partners (AOR = 0.08; 95% CI = 0.01–7.31). This modified ASK model provided better fit than the ASK model, as it explained more variance in HIV testing (47 vs. 29.8%). Recognising factors associated with HIV testing among MMTDs enables us to create suitable public health intervention strategies.     

Sampling Males Who Inject Drugs in Haiphong,Vietnam: Comparison of Time-Location and Respondent-Driven Sampling Methods

Accurate measurements of HIV prevalence and associated risk factors among hidden and high-risk groups are vital for program planning and implementation. However, only two sampling methods are purported to provide representative estimates for populations without sampling frames: time-location sampling (TLS) and respondent-driven sampling (RDS). Each method is subject to potential biases and questionable reliability. In this paper, we evaluate surveys designed to estimate HIV prevalence and associated risk factors among people who inject drugs (PWID) sampled through TLS versus RDS. In 2012, males aged ≥16 years who reported injecting drugs in the previous month and living in Haiphong, Vietnam, were sampled using TLS or RDS. Data from each survey were analyzed to compare HIV prevalence, related risk factors, socio-demographic characteristics, refusal estimates, and time and expenditures for field implementation. TLS (n = 432) and RDS (n = 415) produced similarly high estimates for HIV prevalence. Significantly lower proportions of PWID sampled through RDS received methadone treatment or met an outreach worker. Refusal estimates were lower for TLS than for RDS. Total expenditures per sample collected and number of person-days of staff effort were higher for TLS than for RDS. Both survey methods were successful in recruiting a diverse sample of PWID in Haiphong. In Vietnam, surveys of PWID are conducted throughout the country; although the refusal estimate was calculated to be much higher for RDS than TLS, RDS in Haiphong appeared to sample PWID with less exposure to services and required fewer financial and staff resources compared with TLS.     

Total fluid intake of children and adolescents: cross-sectional surveys in 13 countries worldwide

Purpose

To describe total fluid intake (TFI) according to socio-demographic characteristics in children and adolescents worldwide.

Methods

Data of 3611 children (4–9 years) and 8109 adolescents (10–18 years) were retrieved from 13 cross-sectional surveys (47 % males). In three countries, school classes were randomly recruited with stratified cluster sampling design. In the other countries, participants were randomly recruited based on a quota method. TFI (drinking water and beverages of all kinds) was obtained with a fluid-specific record over 7 consecutive days. Adequacy was assessed by comparing TFI to 80 % of adequate intake (AI) for total water intake set by European Food Safety Authority. Data on height, weight and socio-economic level were collected in most countries.

Results

The mean (SD) TFI ranged from [1.32 (0.68)] to [1.35 (0.71)] L/day. Non-adherence to AIs for fluids ranged from 10 % (Uruguay) to >90 % (Belgium). Females were more likely to meet the AIs for fluids than males (4–9 years: 28 %, OR 0.72, p = 0.002; 10–18 years: 20 %, OR 0.80, p = 0.001), while adolescents were less likely to meet the AI than children (OR 1.645, p < 0.001 in males and OR 1.625, p < 0.001 in females).

Conclusions

A high proportion of children and adolescents are at risk of an inadequate fluid intake. This risk is especially high in males and adolescents when compared with females or children categories. This highlights water intake among young populations as an issue of global concern.

     

Pre-cut papillotomy with a new papillotome

BACKGROUND: A new papillotome has been developed, an isolated-tip needle-knife papillotome (Iso-Tome) that has a semi-oval-shaped tip of epoxide adhesive to prevent electric leakage from the tip of the incising needle. The coated tip aids in keeping the papillotome tightly in the orifice of the ampulla of Vater and is believed to prevent unintentional deep cuts or perforations. This study was done to evaluate the clinical usefulness of the new papillotome for pre-cut papillotomy. METHODS: From June 2003 to November 2003, 115 patients underwent attempted ERCP. If biliary cannulation failed by the conventional method, pre-cut papillotomy was performed by using the Iso-Tome in the direction of the bile duct. After successful bile-duct cannulation, papillotomy was extended for therapeutic procedures, such as stone removal or stent insertion, in the majority of the cases. Post-ERCP complications were classified according to consensus guidelines. OBSERVATIONS: Pre-cut papillotomy with the Iso-Tome was done in 25 patients (21.7% of cases). Protective pancreatic stents were not used. Of these patients, 11 had common bile duct stones, 7 had pancreatitis, 5 had malignancies, one had sphincter of Oddi dysfunction, and one had bile-duct leak. After pre-cut papillotomy with the Iso-Tome, bile-duct cannulation was successfully achieved in 23 of 25 (92%) patients. Complications occurred in 7 of 25 patients (28%) and consisted of mild pancreatitis in 5 (20%), moderate bleeding in one (4%), and biliary pain in one (4%). All 7 patients with complications were managed medically, and there was no death. CONCLUSIONS: In this pilot study, the isolated-tip needle knife was found to be a clinically useful papillotome for pre-cut papillotomy. Further large comparative studies (with and without pancreatic protective stents) are needed to determine improved efficacy and safety compared with standard techniques.     

Impairment in cognitive and exercise performance during prolonged antarctic residence: effect of thyroxine supplementation in the polar triiodothyronine syndrome

Humans who work in Antarctica display deficits in cognition, disturbances in mood, increased energy requirements, a decline of thyroid hormone products, and an increase of serum TSH. We compared measurements in 12 subjects, before deployment (baseline), with 11 monthly studies during Antarctic residence (AR). After 4 months of AR (period 1), half of the subjects (T(4) group) received L-thyroxine [64 nmol.day(-)(1) (0.05 mg.day(-)(1))]; and the other half, a placebo (placebo group) for the next 7 months of AR (period 2). During period 1, there was a 12.3 +/- 5.1% (P < 0.03) decline on the matching-to-sample (M-t-S) cognitive task and an increase in depressive symptoms, compared with baseline. During the intervention in period 2, M-t-S scores for the T(4)-treated group returned to baseline values; whereas the placebo group, in contrast, showed a reduced M-t-S score (11.2 +/- 1.3%; P < 0.0003) and serum free T(4) (5.9 +/- 2.4%; P < 0.02), compared with baseline. The change in M-t-S score was correlated with the change in free T(4) (P < 0.0003) during both periods, and increases in serum TSH preceded worsening scores in depression, tension, anger, lack of vigor, and total mood disturbance (P < 0.001) during period 2. Additionally, the submaximal work rate for a fixed O(2) use decreased 22.5 +/- 4.9% in period 1 and remained below baseline in period 2 (25.2 +/- 2.3%; P < 0.005) for both groups. After 4 months of AR, the L-thyroxine supplement was associated with improved cognition, which seems related to circulating T(4). Submaximal exercise performance decrements, observed during AR, were not changed with this L-thyroxine dose.