New portable smartphone-based PDMS microfluidic kit for the simultaneous colorimetric detection of arsenic and mercury

A smartphone-based microfluidic platform was developed for point-of-care (POC) detection using surface plasmon resonance (SPR) of gold nanoparticles (GNPs). The simultaneous colorimetric detection of trace arsenic and mercury ions (As³⁺ and Hg²⁺) was performed using a new image processing application (app). To achieve this goal, a microfluidic kit was fabricated using a polydimethylsiloxane (PDMS) substrate with the configuration of two separated sensing regions for the quantitative measurement of the color changes in GNPs to blue/gray. To fabricate the microfluidic kit, a Plexiglas mold was cut using a laser based on the model obtained from AutoCAD and Comsol outputs. The colorimetric signals originated from the formation of nanoparticle aggregates through the interaction of GNPs with dithiothreitol – 10,12-pentacosadiynoic acid (DTT-PCDA) and lysine (Lys) in the presence of As³⁺ and Hg²⁺ ions. This assembly exhibited the advantages of simplicity, low cost, and high portability along with a low volume of reagents and multiplex detection. Heavy Metals Detector (HMD), as a new app for the RGB reader, was programmed for an Android smartphone to quantify colorimetric analyses. Compared with traditional image processing, this app provided significant improvements in sensitivity, time of analysis, and simplicity because the color intensity is measured through a new normalization equation by converting RGB to an Integer system. As a simple, real-time, and portable analytical kit, the fabricated sensor could detect low concentrations of As³⁺ (710 to 1278 μg L⁻¹) and Hg²⁺ (10.77 to 53.86 μg L⁻¹) ions in water samples at ambient conditions.

A smartphone-based microfluidic platform was developed for point-of-care (POC) detection using surface plasmon resonance (SPR) of gold nanoparticles (GNPs).     

Continuation rates and reasons for discontinuation of intra-uterine device in three provinces of Pakistan: results of a 24-month prospective client follow-up

Background

Long-acting reversible contraceptives, such as the intrauterine device (IUD), remain underutilised in Pakistan with high discontinuation rates. Based on a 24-month prospective client follow-up (nested within a larger quasi-experimental study), this paper presents the comparison of two intervention models, one using private mid-level providers branded as “Suraj” and the other using community midwives (CMWs) of Maternal Newborn and Child Health Programme, for method continuation among IUD users. Moreover, determinants of IUD continuation and the reasons for discontinuation, and switching behaviour were studied within each arm.

Methods

A total of 1,163 IUD users, 824 from Suraj and 339 from the CMW model, were enrolled in this 24-month prospective client follow-up. Participants were followed-up by female community mobilisers physically every second month to ascertain continued IUD usage and to collect information on associated factors, switching behaviour, reasons for discontinuation, and pregnancy occurrence. The probabilities of IUD continuation and the risk factors for discontinuation were estimated by life table analysis and Cox proportional-hazard techniques, respectively.

Results

The cumulative probabilities of IUD continuation at 24 months in Suraj and CMW models were 82% and 80%, respectively. The difference between the two intervention areas was not significant. The probability distributions of IUD continuation were also similar in both interventions (Log rank test: χ² = 0.06, df = 1, P = 0.81; Breslow test: χ² = 0.6, df = 1, P = 0.44). Health concerns (Suraj = 57.1%, CMW = 38.7%) and pregnancy desire (Suraj = 29.3%, CMW = 40.3%) were reported as the most prominent reasons for IUD discontinuation in both intervention arms. IUD discontinuation was significantly associated with place of residence in Suraj and with age (15–25 years) in the CMW model.

Conclusion

CMWs and private providers are equally capable of providing quality IUD services and ensuring higher method continuation. Pakistan’s National Maternal Newborn and Child Health programme should consider training CMWs and providing IUDs through them. Moreover, private sector mid-level providers could be engaged in promoting the use of IUDs.

     

Effects of melatonin supplementation on disease activity,oxidative stress,inflammatory, and metabolic parameters in patients with rheumatoid arthritis: a randomized double-blind placebo-controlled trial

Clinical Rheumatology - Considering the pathologic significance of inflammation and oxidative stress in rheumatoid arthritis (RA) as well as the antioxidant, anti-inflammatory and hypolipidemic...     

Cannabidiol promotes neurogenesis in the dentate gyrus during an abstinence period in rats following chronic exposure to methamphetamine

Metabolic Brain Disease - Chronic methamphetamine (meth) abuse can lead to certain deficits in the hippocampal function by affecting the hippocampal neurogenesis and plasticity. To determine...     

Multispectral autofluorescence characteristics of reproductive aging in old and young mouse oocytes

Biogerontology - Increasing age has a major detrimental impact on female fertility, which, with an ageing population, has major sociological implications. This impact is primarily mediated through...     

The role of bile leak testing in liver resection: a systematic review and meta-analysis

Background

Bile leak following liver resection can be associated with significant morbidity. This systematic review and meta-analysis aims to evaluate the effect of intraoperative bile leak testing on postoperative bile leak rate and other complications after liver resection without biliary reconstruction for any cause.

High sustained response to daily dosing of interferon with ribavirin in chronic hepatitis C patients naïve to therapy

Background : Viral kinetics suggests that daily administration of α‐interferon (IFN) will clear hepatitis C virus (HCV) RNA earlier and more frequently compared with standard t.i.w. To reduce the likelihood of viral replication, mutation and subsequent development of resistance, daily dosing with IFN may be appropriate. To determine the safety and efficacy of daily IFN with ribavirin in chronic HCV infection we performed a prospective study. Methods : Thirty‐five naïve adult HCV‐positive patients (25 male/10 female) were treated with IFN‐α2b; 5 MU daily for 2 weeks followed by 3 MU daily for 22 weeks and ribavirin 800–1200 mg/day depending on weight. Liver biopsy, performed in 25 patients, showed mild to moderate activity in 19 patients (76%) and severe activity in six patients (24%). Two patients showed staged IV fibrosis. Serotyping was performed in 29 patients by an enzyme immunoassay‐based Murex assay. Type 3 was the predominant serotype, present in 14 cases. Hepatitis C virus RNA was measured by the Chiron bDNA assay. Results : Mean baseline HCV‐RNA level was 14.2 ± 18.7 MEq/mL (median 6.09; range 0.2–92.5), which became undetectable in all but three patients at week 4. Normalization of alanine aminotransferase (ALT) at week 4 was seen in 27 patients. Three patients withdrew due to non‐compliance. Thirty‐two patients completed 24 weeks of therapy as per the protocol. At the end of treatment, the HCV‐RNA level was negative in 29 of 32 patients (90.6%) and ALT was normal in 31 of 32 patients (97%). Sustained viral response at 6 months follow up was seen in 28 of 32 patients (88%). The ALT level was normal in 28 of 32 patients (88%). Conclusion : Daily administration of IFN with ribavirin is well tolerated in the majority of patients. There is rapid elimination of virus with normalization of ALT and a significantly high sustained viral response. © 2002 Blackwell Publishing Asia Pty Ltd     

Short-term effects of ambient (outdoor) air pollution on cardiovascular death in Tehran,Iran – a time series study

Abstract

The aim of this study was to estimate the effect of ambient air pollutants on cardiovascular deaths in Tehran, Iran. In this time series study, air pollutant data were acquired from the Environmental Protection Agency. Meteorological data were acquired from the meteorological organization, and death data were acquired from the Tehran’s cemetery registration. Generalized Additive Models (GAM) were used for estimating the Rate Ratio. NO₂, SO₂ and PM₁₀ were associated with total cardiovascular deaths. PM₁₀ and NO₂ showed stronger relations with deaths in the elder age group. The result of this study showed that NO_2, SO₂, PM₁₀ and O₃ are probably responsible for part of the cardiovascular deaths that happen daily in Tehran.     

Single-Domain Antibodies or Nanobodies: A Class of Next-Generation Antibodies

Nanobodies for the first time were identified in the sera of Camelidae. Single-domain antibodies or nanobodies are a class of next-generation antibodies that have specific features: small size (in nanoscale), high penetration in various tissues, high stability in hard situations and ease production process in microbial systems. In fact single-domain antibodies are the smallest fragment of the antibody with binding ability. Unique characteristics and features of nanobodies make them an appropriate candidate for further evaluation as the development of novel antibody-based therapeutics. In this regard single-domain antibodies are in the interest of many researchers as well as biopharmaceutical companies for diagnostic and therapeutic applications. Nowadays several single domain antibodies have been developed and evaluated in different clinical trials. Because of many advantages of single-domain antibodies over other formats of antibodies, they could be good replacement for other formats of antibodies in near future. Here, we review the biology, engineering platforms and application of nanobodies.