Decision-making process in seeking antenatal care: A cohort study in a poor urban and a typical rural area in Bangladesh.

Background: Decision-making in choosing and using maternal health care among different care-seeking options is a complex process influenced by multilevel factors. Existing evidence on maternal health care-seeking behaviour stems primarily from cross-sectional studies with limited information. Therefore, we designed a cohort study to better understand the decision-making process in antenatal care (ANC) seeking. Methods: We conducted this mixed-methods study among pregnant women at <27 weeks of gestation in a poor urban area (n = 1320) and a typical rural area of Bangladesh (n = 1239) whom we followed up till eight weeks after delivery. In view of quantitative methods, we interviewed all enrolled women 5-6 times four weeks apart. For the qualitative approach, we conducted 70 case studies in the urban area and 46 in the rural area by interviewing the participants and their close family members. Results: In the urban area, about one-third of the pregnant women (38.4%) sought ANC at non-governmental organisations, and nearly an equal proportion went to public facilities (36.6%). In both the situations, women preferred facilities with one-stop services at a reasonable cost. In contrast, the lack of readiness in public facilities of the rural area pushed women (77.8%) toward private facilities for ANC. The reputation of the facilities, availability of skilled care providers, diagnostic tests, and ultrasonography services therein were the key influencing factors in the participants' decisions to seek ANC services from specific facilities. Conclusions: The availability of one-stop services was a key factor for participants' choosing of a facility for ANC. For the urban setting, there is a need to establish large public facilities with one-stop service provision in different zones, along with supporting non-governmental organisations in poor areas. For the rural setting, there is an urgent need to strengthen ANC service provision in public facilities at the community- and the sub-district level to redirect women from the private to the public sector to ensure low cost, quality services.

Patterns of common illness and injury of readymade garment workers and a review of safety practices in Bangladesh.

BACKGROUND: Readymade garment workers globally experience distinctive vulnerabilities at the workplace. The situation is worse in many developing countries. However, there is a lack of scientific evidence about the health and safety of garment workers in the workplace. OBJECTIVE: The objective of this study was to examine the patterns of illness and injury of garment workers, factory level health safety policies and programs, and views and perception of management staff at factories in Bangladesh. METHODS: This mixed-method study was conducted among garment workers and management level staff between January 2018 and April 2019. We extracted 4000 health records of the workers who attended primary health care centers of the factories and conducted 11 key informant interviews using qualitative method from different management-level staff. RESULTS: Half of the workers (51.0%) were working in the sewing section following 12.8% in quality control and 12.3% in the laundry section. A review of the medical records showed that peptic ulcer diseases (PUDs) (19.2%), fever (11.7%), loose motion (10.3%), and headache (9.4%). Needle injury was uncommon for taking medical care. Occupational safety and health management, safe drinking water, access to maternity leave and other facilities were better in large and medium factories compared with those in small factories. CONCLUSIONS: Although the readymade garments sector is one of the largest sources of foreign currency revenue earnings in Bangladesh, occupational health and safety issues of workers remain a big concern. Thus, support from the government needs more focus on the health and safety of workers.

Novel electrochemical PMI marker biosensor based on quantum dot dissolution using a double-label strategy.

A novel and facile post-mortem interval (PMI) biosensor was fabricated using a double-label strategy to detect the glyceraldehyde 3-phosphate dehydrogenase (GAPDH) biomarker. A monoclonal anti-GAPDH antibody was immobilized on a surface label containing cadmium selenide quantum dots (CdSe QDs) on a cysteamine graphene oxide (Cys-GO) self-assembled monolayer. Glucose oxidase (GOx) was used as a signal label to conjugate with GAPDH. GAPDH recognition was achieved through the dissolution of the surface-attached CdSe QDs by hydrogen peroxide generated through GAPDH-conjugated GOx-catalyzed ß-glucose oxidation. To enhance sensitivity, a competitive interaction was introduced between free and conjugated GAPDH to the active site of the anti-GAPDH antibody. The electrochemical response due to CdSe dissolution decreased proportionally with the concentration of free GAPDH. Differential pulsed voltammetry was conducted to determine the analytical characteristics of the immunosensor, including the limit of detection, linear dynamic range, target selectivity, system stability, and applicability toward the analysis of real samples.

Au@ZIF-8 SERS paper for food spoilage detection.

Putrescine and cadaverine are important volatile indicators for the evaluation of food spoilage. In this study, a metal-organic framework (MOF)-coated surface-enhanced Raman scattering (SERS) paper platform for the detection of putrescine and cadaverine is developed. Au@ zeolite imidazolate framework-8 (ZIF-8) SERS paper is fabricated by the coating of ZIF-8 layer on a Au nanoparticle-impregnated paper that is prepared by dry plasma reduction. The Au@ZIF-8 SERS paper is characterized by scanning electron microscope, energy-dispersive X-ray spectroscopy, X-ray diffraction, and N2 sorption isotherm. The ZIF-8 layer enables the accumulation of gaseous molecules and also provides enhancement of SERS signals. The fluorescence, SERS, and simulation results prove the improved detection ability of the Au@ZIF-8 platform for the volatile molecules. For the selective detection of putrescine and cadaverine, the Au@ZIF-8 SERS paper is functionalized with 4-mercatobenzaldehyde (4-MBA). The 4-MBA molecule acts as a Raman reporter and also a specific receptor for the volatile amine molecules. Using the intensity ratiometric detection of 4-MBA-functionalized Au@ZIF-8 SERS paper, putrescine and cadaverine are quantitatively detected with detection limits of 76.99 and 115.88 parts per billion, respectively. Furthermore, the detection of volatile amine molecules released from spoiled salmon, chicken, beef, and pork samples is demonstrated. It is anticipated that the MOF-coated SERS paper platforms will be applicable not only in food safety but other applications including disease diagnosis and environmental monitoring.

Enhanced Surface Properties of Light-Trapping Si Nanowires Using Synergetic Effects of Metal-Assisted and Anisotropic Chemical Etchings.

Metal-assisted chemical etching (MACE) has been widely explored for developing silicon (Si)-based energy and optical devices with its benefits for low-cost and large-area fabrication of Si nanostructures of high aspect ratios. Surface structures and properties of Si nanostructures fabricated through MACE are significantly affected by experimental and environmental conditions of etchings. Herein, we showed that surfaces and interfacial energy states of fabricated Si nanowires can be critically affected by oxidants of MACE etching solutions. Surfaces of fabricated Si nanowires are porous and their tips are fully covered with lots of Si nano-sized grains. Strongly increased photoluminescence (PL) intensities, compared to that of the crystalline Si substrate, are observed for MACE-fabricated Si nanowires due to interfacial energy states of Si and SiOx of Si nano-sized grains. These Si grains can be completely removed from the nanowires by an additional etching process of the anisotropic chemical etching (ACE) of Si to taper the nanowires and enhance light trapping of the nanowires. Compared with the MACE-fabricated Si nanowires, ACE-fabricated tapered Si nanowires have similar Raman and PL spectra to those of the crystalline Si substrate, indicating the successful removal of Si grains from the nanowire surfaces by the ACE process.

Femtomolar detection of cardiac troponin I using a novel label-free and reagent-free dendrimer enhanced impedimetric immunosensor.

A novel highly sensitive dendrimer coupled impedimetric immunosensor was developed for the label-free and reagent-free detection of cardiac troponin I (TnI) in serum samples. The immunosensor probe was fabricated by covalently attaching carboxylic acid-functionalized third generation (G3) poly (amidoamine) (PAMAM) dendrimer (Den) on the 3, 3', 5, 5'-tetramethyl benzidine (TMB) modified 6-mercaptohexanoic acid (MHA) self-assembled monolayer (SAM) on a gold (Au) electrode. Monoclonal anti-TnI antibody was then covalently immobilized on the Den and TMB attached MHA SAM modified surface. TMB was used as an internal surface redox couple for generating signal which also allowed to avoid the use of an external one (i.e. ferricyanide couple) in solution during the impedance measurement for monitoring the antibody-antigen binding. On the other hand, Den was used as a signal enhancer by immobilizing more anti-body on the immunosensor probe. The immunosensor probe was characterized using X-ray photoelectron spectroscopy (XPS), quartz crystal microbalance (QCM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) techniques. The TnI detection in diluted serum was based on the measurement of charge transfer resistance (Rct) of the electron transfer process of the surface-attached TMB before and after immunobinding. Under the optimized condition, the proposed immunosensor could detect human TnI in diluted serum samples as low as 11.7 fM with a wide linear dynamic range, good stability, and excellent specificity. The validity of the proposed method was tested in various TnI spiked human undiluted serum samples and was compared with the enzyme-linked immunosorbent assay (ELISA). The results suggested that the proposed immunosensor could be a useful tool for practical applications in clinical diagnosis.

Barriers to Timely and Safe Blood Transfusion for PPH Patients: Evidence from a Qualitative Study in Dhaka, Bangladesh.

BACKGROUND AND OBJECTIVES: In Bangladesh, postpartum hemorrhage (PPH) is the leading cause of maternal mortality accounting for 31% of all blood transfusions in the country. Although safe blood transfusion is one of the 8 signal functions of Comprehensive Emergency Obstetric Care (CEmOC) strategy, most of the designated public sector CEmOC facilities do not have on-site blood storage system. Emergent blood is mainly available from external blood banks. As a result, emergent patients are to rely on an unregulated network of brokers for blood which may raise question about blood safety. This study explored lived experiences of patients' attendants, managers, providers, and blood brokers before and after the implementation of an on-line Blood Information and Management Application (BIMA) in regards to barriers and facilitators of blood transfusion for emergent patients. METHODS: Data were collected at Dhaka Medical College Hospital (DMCH), a tertiary-level teaching hospital before (January 2014) and after (March 2015) the introduction of an online BIMA system. Data collection methods included 24 key informant interviews (KIIs) and 40 in-depth interviews (IDIs). KIIs were conducted with formal health service providers, health managers and unlicensed blood brokers. IDIs were conducted with the relatives and husbands of women who suffered PPH, and needed emergency blood. RESULTS: Patients' attendants were unaware of patients' blood type and availability of blood in emergency situation. Newly introduced online BIMA system could facilitate blood transfusion process for poor patients at lower cost and during any time of day and night. However, service providers and service recipients were heavily dependent on a network of unlicensed blood brokers for required blood for emergent PPH patients. Blood collected through unlicensed blood brokers is un-screened, unregulated and probably unsafe. Blood brokers feel that they are providing a needed service, acknowledged a financial incentive and unaware about safety of blood that they supply. CONCLUSIONS: Ensuring safe and timely blood transfusion is necessary to end preventable maternal mortality. In a context where facilities have no on-site blood, and both providers and patient attendants are heavily dependent on an unregulated cadre of unlicensed blood brokers, access to timely safe blood transfusion is seriously threatened. BIMA is a promising intervention to reduce inefficiencies in obtaining blood, but steps must be taken to ensure buy-in from current purveyors of blood, and to increase the acceptance of the intervention.

Detection of Prostate Specific Membrane Antigen at Picomolar Levels Using Biocatalysis Coupled to Assisted Ion Transfer Voltammetry at a Liquid-Organogel Microinterface Array.

A label-free electrochemical strategy for the detection of a cancer biomarker, prostate specific membrane antigen (PSMA), at picomolar concentrations without the use of antibodies, was investigated. The approach is based on the assisted ion transfer of protons, generated by a series of enzymatic reactions, at an array of microinterfaces between two immiscible electrolyte solutions (µ-ITIES). This nonredox electrochemical approach based on biocatalysis-coupled proton transfer at the µ-ITIES array opens a new way to detect the prostate cancer biomarker, with detection capability achieved at concentrations below those indicative of disease presence. The strategy is expected to contribute to cancer diagnostics, recurrence monitoring, and therapeutic treatment efficacy.

Ultrasensitive Nanoimmunosensor by coupling non-covalent functionalized graphene oxide platform and numerous ferritin labels on carbon nanotubes.

An ultrasensitive electrochemical nanostructured immunosensor for a breast cancer biomarker carbohydrate antigen 15-3 (CA 15-3) was fabricated using non-covalent functionalized graphene oxides (GO/Py-COOH) as sensor probe and multiwalled carbon nanotube (MWCNTs)-supported numerous ferritin as labels. The immunosensor was constructed by immobilizing a monoclonal anti-CA 15-3 antibody on the GO modified cysteamine (Cys) self-assembled monolayer (SAM) on an Au electrode (Au/Cys) through the amide bond formation between the carboxylic acid groups of GO/Py-COOH and amine groups of anti-CA 15-3. Secondary antibody conjugated MWCNT-supported ferritin labels (Ab2-MWCNT-Ferritin) were prepared through the amide bond formation between amine groups of Ab2 and ferritin and carboxylic acid groups of MWCNTs. The detection of CA 15-3 was based on the enhanced bioelectrocatalytic reduction of hydrogen peroxide mediated by hydroquinone (HQ) at the GO/Py-COOH-based sensor probe. The GO/Py-COOH-based sensor probe and Ab2-MWCNT-Ferritin labels were characterized using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electron microscope (SEM), transmission electron microscope (TEM), and x-ray photoelectron spectroscopy (XPS) techniques. Using differential pulse voltammetry (DPV) technique, CA 15-3 can be selectively detected as low as 0.01 ± 0.07 U/mL in human serum samples. Additionally, the proposed CA 15-3 immunosensor showed excellent selectivity and better stability in human serum samples, which demonstrated that the proposed immunosensor has potentials in proteomic researches and diagnostics.

A highly sensitive quartz crystal microbalance immunosensor based on magnetic bead-supported bienzymes catalyzed mass enhancement strategy.

A highly sensitive quartz crystal microbalance (QCM) immunosensor based on magnetic bead-supported bienzyme catalyzed mass enhanced strategy was developed for the detection of human immunoglobulin G (hIgG) protein. The high sensitive detection was achieved by increasing the deposited mass on the QCM crystal through the enhanced precipitation of 4-chloro-1-naphthol (CN) using higher amounts of horseradish peroxidase (HRP) and glucose oxidase (GOx) bienzymes attached on the magnetic beads (MB). The protein A (PA) and capture antibody (monoclonal anti-human IgG antibody produced in mouse, Ab1)-based QCM probe and the detection antibody (anti-human IgG antibody produced in goat, Ab2)-based MB/HRP/GOx bienzymatic bioconjugates were characterized using scanning electron microscope, transmission electron microscope, cyclic voltammetry, and electrochemical impedance spectroscopy techniques. Under the optimized experimental condition, the linear range and the detection limit of hIgG immunosensor were determined to be 5.0pg/mL-20.0ng/mL and 5.0±0.18pg/mL, respectively. The applicability of the present hIgG immunosensor was examined in hIgG spiked human serum samples and excellent recoveries of hIgG were obtained.

Stimulated mass enhancement strategy-based highly sensitive detection of a protein in serum using quartz crystal microbalance technique.

A stimulated mass enhancement strategy based on enormous biocatalytic precipitation of 4-chloro-1-naphthol using magnetic bead-supported horseradish peroxidase and glucose oxidase bienzymes was developed for the highly sensitive detection of interleukin-6 in serum using a quartz crystal microbalance technique.

Sensitivity enhancement of an electrochemical immunosensor through the electrocatalysis of magnetic bead-supported non-enzymatic labels.

An ultrasensitive non-enzymatic electrochemical carcinoembryonic antigen (CEA) immunosensor was fabricated by the immobilization of a monoclonal CEA antibody (anti-CEA) on a protein A (PA) attached-gold nanoparticles (AuNPs)-deposited electrochemically prepared polydopamine film (e-PD/AuNPs). Magnetic beads (MB)-supported and CEA-conjugated multiple 3,3',5,5'-tetramethylbenzidine (TMB) was used as electrochemical labels. The detection was based on the measurements of the electrocatalyzed oxidation of ascorbic acid (AA) by the multiple TMB labels after competitive binding between MB/TMB-conjugated-CEA and free-CEA. The electrocatalyzed oxidation current of AA by TMB decreased with increasing concentration of the free-CEA as the amount of CEA/MB/TMB labels decreased at the immunosensor probe. The immunosensor surface was characterized using electrochemical impedance spectroscopy, Fourier transform infrared spectroscopy, quartz crystal microbalance, and scanning electron microscopy techniques. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques were used to monitor the electrocatalyzed response. The proposed immunosensor exhibited a wide linear dynamic range (1.0 pg/mL to 10.0 ng/mL), low detection limit (1.0±0.04 pg/mL), good selectivity, and long-time stability. It was successfully applied to various CEA spiked human serum samples for the detection of CEA.

A stable and sensitive voltammetric immunosensor based on a new non-enzymatic label.

A stable and sensitive electrochemical carcinoembryonic antigen immunosensor based on a new non-enzymatic label (3, 3', 5, 5'-tetramethylbenzidine (TMB)) was fabricated using gold nanoparticles-deposited polydopamine film (PD/AuNPs) as an anti-CEA antibody immobilizing platform. TMB was conjugated with CEA and utilized as an electrochemical label. The PD/AuNPs platform provides enhanced conductivity, thus the redox reaction of TMB label was observed at the immunosensor probe. The immunosensor probe was characterized using scanning electron microscopy and electrochemical impedance spectroscopy. The CEA detection was based on the competitive binding of free- and TMB-conjugated-CEA to the anti-CEA antibody. Using differential pulse voltammetry, CEA can be selectively detected as low as 10±0.6 pg/mL. The present immunosensor method was applied to CEA-spiked human serum samples and the recovery results were satisfactory.

Increased electrocatalyzed performance through dendrimer-encapsulated gold nanoparticles and carbon nanotube-assisted multiple bienzymatic labels: highly sensitive electrochemical immunosensor for protein detection.

A highly sensitive electrochemical carcinoembryonic antigen (CEA) immunosensor was fabricated by covalently immobilizing a monoclonal CEA antibody (anti-CEA, Ab(1)) and a mediator (thionine, Th) on a gold nanoparticle (AuNP)-encapsulated dendrimer (Den/AuNP). Multiwalled carbon nanotube (MWCNT)-supported secondary antibody (Ab(2))-conjugated multiple bienzymes, glucose oxidase (GOx), and horseradish peroxidase (HRP) (Ab(2)/MWCNT/GOx/HRP) were used as electrochemical labels. The highly sensitive detection was achieved by the increased HRP-electrocatalyzed reduction of hydrogen peroxide, which was locally generated by the enzyme GOx. The immunosensor surface was characterized using electrochemical impedance spectroscopy, atomic force microscopy, and quartz crystal microbalance techniques. The Den/AuNP and Ab(2)/MWCNT/GOx/HRP bioconjugates were characterized using high-resolution transmission electron microscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy. Cyclic voltammetry and square wave voltammetry techniques were used to monitor the increased electrocatalyzed reduction of hydrogen peroxide by HRP. The linear dynamic range and the detection limit were determined to be 10.0 pg/mL to 50.0 ng/mL and 4.4 ± 0.1 pg/mL, respectively. The validity of the immunosensor response was tested in various CEA-spiked human serum samples, and the results were compared to those of an enzyme-linked immunosorbent assay method.

Amplified electrochemical detection of a cancer biomarker by enhanced precipitation using horseradish peroxidase attached on carbon nanotubes.

An electrochemical nanoimmunosensor based on multiwall carbon nanotubes (MWCNTs)/gold nanoparticles (AuNPs) was developed for the amplified detection of prostate specific antigen (PSA). The amplified detection was achieved by the enhanced precipitation of 4-chloro-1-naphthol (CN) using a higher number of horseradish peroxidase (HRP) molecules attached on MWCNTs. The PSA nanoimmunosensor was fabricated by immobilizing a monoclonal anti-PSA antibody (anti-PSA) on the AuNP-attached thiolated MWCNT on a gold electrode. The sensor surface was characterized using scanning electron microscope, transmission electron microscope, quartz crystal microbalance, and electrochemical techniques. Cyclic and square wave voltammetric techniques were used to monitor the enhanced precipitation of CN that accumulated on the electrode surface and subsequent decrement in the electrode surface area by monitoring the reduction process of the Fe(CN)(6)(3-)/Fe(CN)(6)(4-) redox couple. Under the optimized experimental condition, the linear range and the detection limit of PSA immunosensor were determined to be 1.0 pg/mL to 10.0 ng/mL and 0.40 ± 0.03 pg/mL, respectively. The validity of the proposed method was compared with an enzyme-linked immunosorbent assay method in various PSA spiked human serum samples.

Assessment of ADHD documentation from candidates requesting Americans With Disabilities Act (ADA) accommodations for the National Board of Osteopathic Medical Examiners COMLEX exam.

PURPOSE: Every year increasing numbers of candidates request special accommodations for high-stakes medical licensing examinations, due to ADHD, on the basis of the Americans with Disabilities Act (ADA). This poses significant challenges for both the applicant and the medical boards and has significant financial, legal, and ethical implications. The purpose of this survey is to review all applications requesting ADA accommodations, on the basis of ADHD, submitted to the National Board of Osteopathic Medical Examiners (NBOME) COMLEX exam. METHOD: The authors review all 50 requests for special accommodations, on the basis of ADHD, submitted to the NBOME between 2005 and 2007. All requests are reviewed by the investigators independently and then cross-checked to determine interrater reliability. RESULTS: Of all applicants, only 14% (7/50) provide sufficient documentation to support a diagnosis of ADHD. Interrater reliability is high. CONCLUSIONS: The majority of applicants who request special testing accommodations on the basis of ADHD do not provide adequate documentation to the medical boards to support the diagnosis.