Recent Advances in Two-Dimensional Nanomaterials for Healthcare Monitoring.

The development of advanced technologies for the fabrication of functional nanomaterials, nanostructures, and devices has facilitated the development of biosensors for analyses. Two-dimensional (2D) nanomaterials, with unique hierarchical structures, a high surface area, and the ability to be functionalized for target detection at the surface, exhibit high potential for biosensing applications. The electronic properties, mechanical flexibility, and optical, electrochemical, and physical properties of 2D nanomaterials can be easily modulated, enabling the construction of biosensing platforms for the detection of various analytes with targeted recognition, sensitivity, and selectivity. This review provides an overview of the recent advances in 2D nanomaterials and nanostructures used for biosensor and wearable-sensor development for healthcare and health-monitoring applications. Finally, the advantages of 2D-nanomaterial-based devices and several challenges in their optimal operation have been discussed to facilitate the development of smart high-performance biosensors in the future.

Cooling supply with a new type of evacuated solar collectors: a techno-economic optimization and analysis.

Renewable cooling via absorption chillers being supplied by various green heat technologies such as solar collectors has been widely studied in the literature, but it is still challenging to get positive economic outcomes from such systems due to the large expenses of solar thermal systems. This study offers the use of a new generation of solar collectors, so-called eccentric reflective solar collectors, for driving single-effect absorption chillers and thereby reducing the levelized cost of cooling. This article develops the most optimal design of this system (based on several different scenarios) using multi-objective optimization techniques and employs them for a case study in Brazil to assess its proficiency compared to conventional solar-driven cooling methods. For making the benchmarking analyses fair, the conventional system is also rigorously optimized in terms of design and operation features. The results show that the eccentric solar collector would enhance the cost-effectiveness by 29%. In addition, using optimally sized storage units would be necessary to get acceptable economic performance from the system, no matter which collector type is used. For the case study, at the optimal sizing and operating conditions, the levelized cost of cooling will be 124 USD/MWh and an emission level of 18.97 kgCO2/MWh.

Compact Flexible Planar Antennas for Biomedical Applications: Insight into Materials and Systems Design.

Planar antennas have become an integral component in modern biomedical instruments owing to their compact structure, cost effectiveness, and light weight. These antennas are crucial in realizing medical systems such as body area networks, remote health monitoring, and microwave imaging systems. Antennas intended for the above applications should be conformal and fabricated using lightweight materials that are suitable for wear on the human body. Wearable antennas are intended to be placed on the human body to examine its health conditions. Hence, the performance of the antenna, such as its radiation characteristics across the operating frequency bands, should not be affected by human body proximity. This is achieved by selecting appropriate conformal materials whose characteristics remain stable under all environmental conditions. This paper aims to highlight the effects of human body proximity on wearable antenna performance. Additionally, this paper reviews the various types of flexible antennas proposed for biomedical applications. It describes the challenges in designing wearable antennas, the selection of a flexible material that is suitable for fabricating wearable antennas, and the relevant methods of fabrication. This paper also highlights the future directions in this rapidly growing field. Flexible antennas are the keystone for implementing next-generation wireless communication devices for health monitoring and health safety applications.

Enhanced electrochemical performance of the MoS2/Bi2S3 nanocomposite-based electrode material prepared by a hydrothermal method for supercapacitor applications.

Supercapacitors are widely used energy storage systems in the modern world due to their excellent electrochemical performance, fast charging capability, easy handling, and high power density. In the present work, pure MoS2 and MoS2/Bi2S3 nanocomposites with different compositions of bismuth were synthesized by the hydrothermal method. The structural properties of the electrode materials were studied using the XRD technique, which confirmed the formation of MoS2 and the secondary phase of Bi2S3 while increasing Bi substitution. The morphological studies of the synthesized electrode materials were performed using SEM, TEM, and HRTEM techniques, which indicated the 3D layered hierarchical structure of MoS2 nanospheres and the nanosheet-like structure of Bi2S3. The electrochemical properties of pristine MoS2 and MoS2/Bi2S3 nanocomposites were analysed by CV, CP, and EIS techniques using a 2 M KOH electrolyte in a three-electrode system. The CV curves show evidence of significant improvement in the electrochemical performance of MoS2/Bi2S3 composites compared to that of pure MoS2. The calculated specific capacitances of MoS2/Bi2S3 nanocomposites were relatively higher than those of pristine MoS2. The 20 mol% Bi added sample showed a maximum specific capacitance of 371 F g-1, compared to pristine MoS2 and other samples at a current density of 1 A g-1. The kinetics of the electrochemical process was studied. The Nyquist plots indicated that the Bi-added nanocomposites had lower Resr and RCT values, which resulted in high electrochemical performance. The experimental results revealed that Bi-substitution can further enhance the electrochemical energy storage performance of MoS2 for supercapacitor applications.

Recent Advances in Molybdenum Disulfide and Its Nanocomposites for Energy Applications: Challenges and Development.

Energy storage and conversion are critical components of modern energy systems, enabling the integration of renewable energy sources and the optimization of energy use. These technologies play a key role in reducing greenhouse gas emissions and promoting sustainable development. Supercapacitors play a vital role in the development of energy storage systems due to their high power density, long life cycles, high stability, low manufacturing cost, fast charging-discharging capability and eco-friendly. Molybdenum disulfide (MoS2) has emerged as a promising material for supercapacitor electrodes due to its high surface area, excellent electrical conductivity, and good stability. Its unique layered structure also allows for efficient ion transport and storage, making it a potential candidate for high-performance energy storage devices. Additionally, research efforts have focused on improving synthesis methods and developing novel device architectures to enhance the performance of MoS2-based devices. This review article on MoS2 and MoS2-based nanocomposites provides a comprehensive overview of the recent advancements in the synthesis, properties, and applications of MoS2 and its nanocomposites in the field of supercapacitors. This article also highlights the challenges and future directions in this rapidly growing field.

Calcium Intake and Iron Status in Human Studies: A Systematic Review and Dose-Response Meta-Analysis of Randomized Trials and Crossover Studies.

BACKGROUND: The interaction between dietary (and supplementary) divalent ions has been a long-standing issue in human nutrition research. Developing an optimal calcium and iron supplementation recommendation requires detailed knowledge of the potential trade-offs between: 1) the clinical effects of concurrent intake on iron absorption and hematological indices; and 2) the potentially negative effects of separated ingestion on adherence to iron and/or calcium supplements. Human clinical studies have examined the effects of calcium intake on iron status, but there are no meta-analyses or recent reviews summarizing the findings. OBJECTIVES: To synthesize peer-reviewed, human, randomized, and cross-over studies on effects of calcium consumption on iron indices without age, gender, or any other restrictions. METHODS: Weighted mean differences for total, heme, and nonheme iron absorption (%) and serum ferritin (µg/L) were obtained from pooled analysis of the highest daily calcium intake compared to the lowest daily calcium intake. RESULTS: The negative effect of calcium intake was statistically significant in short-term iron absorption studies, but the effect magnitude was low [weighted mean difference (WMD) = -5.57%; 95% CI: -7.09 to -4.04]. The effect of calcium on the iron status was mixed. The inverse dose-response association of calcium intake with the serum ferritin concentration was significant (P value = 0.0004). There was, however, no reduction in the hemoglobin concentration (WMD = 1.22g/L;  95% CI:  0.37-2.07). CONCLUSIONS: The existing body of studies is insufficient to make recommendations with high confidence due to heterogeneity in designs, limitations of ferritin as an iron biomarker, and a lack of intake studies in pregnant women. Prescribing separation of prenatal calcium and iron supplements in free-living individuals is unlikely to affect the anemia burden. There is a need for effectiveness trials comparing the effects of prescribing separated intake to concurrent intake, with functional endpoints as primary outcomes and adherence to each supplement as intermediate outcomes.

The Prevalence of Occult Hepatitis B Infection among Blood Donors in Lagos, Nigeria.

BACKGROUND: In occult hepatitis B virus (HBV) infection, the HBV DNA is present in the blood or liver tissue in patients negative for hepatitis B surface antigen (HBsAg) with or without anti-HBV antibodies. Thus, the absence of HBsAg in the blood only reduces the risk of transmission and is not sufficient enough to ensure the absence of HBV infection. AIM: This study was aimed at determining the prevalence of occult HBV infection among blood donors in Lagos. STUDY DESIGNS: A cross-sectional study was done among 101 consenting blood donors at Lagos State University Teaching Hospital, Ikeja, between November 2016 and January 2017. MATERIALS AND METHODS: HBV DNA analysis and viral load were done at the Molecular Laboratory of National Sickle Cell Centre, Idi Araba, Lagos, for all the HBsAg negative blood donors screened by rapid kit at Ikeja. RESULTS: The prevalence of occult HBV DNA among the participants was 3% consisting of 3% prevalence of HBV DNA surface antigen and 0% prevalence for precore and core of the HBV DNA. CONCLUSION: The low prevalence (3%) of occult HBV seen in our study does not make it cost-effective to routinely screen blood donors or the general population for HBV infection using DNA polymerase chain reaction.

Serum homocysteine and disease severity in sickle cell anemia patients in Lagos.

Purpose: Hypercoagulability in sickle cell anemia (SCA) may be responsible for the increased development of vascular occlusion in certain organs as well as acute pain episodes. The causes of hypercoagulability in SCA are multifactorial and include raised homocysteine levels. This study, therefore, aimed to determine serum homocysteine levels in SCA patients in steady state and to correlate its levels with SCA disease severity. Patients and Methods: This was a cross-sectional study done among SCA patients in steady state attending the Haematology Clinic of the Lagos State University Teaching Hospital (LASUTH). Matched age and sex HbAA controls were also recruited. Serum homocysteine of each participant was done with enzyme-linked immunosorbent assay and disease severity score assessed in every SCA patient using clinical and laboratory parameters. Results: The mean value for homocysteine in the study group (SCA patients) was 19.80±19.75 µmol/L whilst that of the control group was 9.16±4.29 µmol/L. Thirty-nine out of 96 (46.6%) SCA patients had elevated homocysteine levels (>15 µmol/L) whilst all 96 participants in the control group had normal homocysteine levels. The difference in the means in the two groups was statistically significant with p=0.001. Majority (62.5%) of the SCA patients had a mild disease (severity score ≤3). There was a significant correlation between serum homocysteine levels and disease severity scores with p=0.04; χ2=4.04. Conclusion: Homocysteine levels were significantly higher in HbSS patients compared with matched HbAA controls and showed a positive correlation with disease severity scores in the SCA patients.

Methylene tetrahydrofolate reductase gene mutation in sickle cell anaemia patients in Lagos, Nigeria.

INTRODUCTION: The significant causes of mortality among individuals with sickle cell anaemia (SCA) such as acute chest syndrome and cerebrovascular disease are related to vascular occlusion. Polymorphisms of the methylene tetrahydrofolate reductase (MTHFR) gene in persons with sickle cell anaemia have been suggested as a potential risk for vaso-occlusive events, with the C677T and A1298C polymorphisms being the commonest. This study therefore aimed to establish the pattern of MTHFR C677T and A1298C gene mutations among adults with HbSS phenotype attending the Haematology Clinic in Lagos State University Teaching Hospital Lagos, Nigeria. METHODS: A cross-sectional study was done among SCA patients attending the Haematology Clinic of the Lagos State University Teaching Hospital (LASUTH), using age and sex matched HbAA controls. DNA extraction and gene analysis were done. The selective amplification of a particular segment of the DNA by polymerase chain reaction (PCR) was done and subsequent digestion of the amplified MTHFR gene into its various fragments. RESULTS: The overall prevalence of the C677T mutation among participants was 19.3% (37 of 192), while the prevalence of A1298C was 15% (29 of 192). CONCLUSION: The prevalence of MTHFR C677T was higher than A1298C mutations among sickle cell anaemia subjects.

Gestational thrombocytopaenia among pregnant women in Lagos, Nigeria.

BACKGROUND: Thrombocytopaenia is a common haematologic abnormality during pregnancy. Pregnant women with thrombocytopenia have a higher risk of bleeding excessively during or after childbirth, particularly if they need to have a caesarean section or other surgical intervention during pregnancy, labour or in the puperium. The aim of this study was to determine the prevalence of gestational thrombocytopaenia among pregnant women reporting for antenatal care at tertiary health care centres in Lagos. MATERIALS AND METHODS: Platelet count was analyzed in 274 consecutive pregnant women who gave informed consent and 70 non-pregnant female staff of the hospitals. Platelet count was performed on each sample using the Sysmex KN-21N automated haematology analyzer. The study design was cross-sectional, proportions were analyzed for statistical significance with the chi-square, and Odds ratio was also calculated. Thrombocytopaenia is classically defined as a platelet count of less than 150 × 10(9)/L.34 Counts from 100 to 150 × 10(9)/L are considered mildly depressed, 50 to 100 × 10(9)/L are moderately depressed and less than 50 × 10(9)/L are severely depressed. RESULTS: Thirty-four (13.5%) pregnant women were thrombocytopaenic compared with three (4.3%) non-pregnant women. This was statistically significant; P = 0.03; Odds ratio: 3.5 (95% CI 1.03-11.82). Out of the 37 pregnant women who were thrombocytopaenic, most of them (78%) had mild thrombocytopenia, only 6% had severe thrombocytopaenia. CONCLUSION: The prevalence of gestational thrombocytopaenia in this study was 13.5%. Although majority of the pregnant women had mild thrombocytopaenia, healthcare providers should screen all pregnant women routinely for thrombocytopaenia to avoid excessive bleeding during or after childbirth.

Prevalence of Priapism and Its Awareness amongst Male Homozygous Sickle Cell Patients in Lagos, Nigeria.

Background. Priapism is a pathological condition of penile erection that persists beyond, or is unrelated to, sexual stimulation. Impotence and infertility are major problems in male sickle cell disease patients, and priapism has been implicated as a cause of impotence and infertility. The aim of this study is to determine priapism prevalence and assess the knowledge of male homozygous male patients about it in Lagos, Nigeria. Methods. A cross-sectional study was conducted amongst male homozygous sickle cell disease patients of Lagos State University Teaching Hospital. Pretested questionnaires were distributed to determine the prevalence and assess their knowledge on priapism. Data were analyzed using SPSS version 16.0. Results. A total of 114 consenting subjects filled the questionnaires, 85 of 114 (74.6%) had not heard about priapism before this study. A total of 77 of 114 (67.5%) did not know that they are at risk of priapism. Whilst 84 of 114 (73.7%) were not aware that priapism is a complication of SCD. The majority, 94 of 114 (82.5%), were not aware that priapism could cause impotence. Conclusion. There is a need to create more awareness about this complication amongst sickle cell disease patients in order to stem the incidence of impotence and infertility amongst them.

Hematological profile of normal pregnant women in Lagos, Nigeria.

BACKGROUND: Hematological profile is considered one of the factors affecting pregnancy and its outcome. Anemia is the most common hematological problem in pregnancy, followed by thrombocytopenia. Leukocytosis is almost always associated with pregnancy. The study reported here was designed to evaluate the overall mean values of seven major hematological parameters and their mean values at different trimesters of pregnancy. SUBJECTS AND METHODS: This examination was a cross-sectional study of 274 pregnant women who registered to attend the Lagos University Teaching Hospital or Lagos State University Teaching Hospital antenatal clinics between their first and third trimester. Blood (4.5 mL) was collected from each participant into a tube containing the anticoagulant ethylenediaminetetraacetic acid (EDTA). A full blood count was performed on each sample and the results were analyzed. RESULTS: Overall, the values obtained were (mean ± standard deviation [SD]): hematocrit level, 30.16% ± 5.55%; hemoglobin concentration, 10.94 ± 1.86 g/dL; white blood cells, 7.81 ± 2.34 × 10(9); platelets, 228.29 ± 65.6 × 10(9); cell volume 78.30 ± 5.70 fL, corpuscular hemoglobin, 28.57 ± 2.48 pg; and corpuscular hemoglobin concentration, 36.45 ± 1.10 g/dL. When grouped by trimester, the mean ± SD value of packed cell volume at first trimester was 32.07% ± 6.80%; of second trimester, 29.76% ± 5.21%; and of third, 33.04% ± 3.88%. The mean ± SD hemoglobin concentration values were 11.59 ± 2.35 g/dL, 10.81 ± 1.72 g/dL, and 10.38 ± 1.27 g/dL for women in their first, second, and third trimester, respectively. Mean ± SD white blood cell concentration for first, second, and third trimesters were 7.31 ± 2.38 × 10(9), 7.88 ± 2.33 × 10(9), and 8.37 ± 2.15 × 10(9), respectively, while the mean ± SD platelet values for first, second, and third trimesters were 231.50 ± 79.10 × 10(9), 227.57 ± 63 × 10(9), and 200.82 ± 94.42 × 10(9), respectively. A statistically significant relationship was found to exist between packed cell volume and white blood cell count with increase in gestational age (P = 0.010 and 0.001, respectively). However, there was no statistically significant association between platelet count and increase in gestational age (P = 0.296). CONCLUSION: These findings reinforce the need for supplementation and provide additional information on hematological reference values in pregnancy in Nigeria.

Comparison of 20-, 23-, and 25-gauge air infusion forces.

PURPOSE: To determine and compare 20-, 23-, and 25-gauge retinal infusion air jet impact pressure (force per unit area) in an experimental setting. METHODS: Experimental laboratory investigation. Infusion cannulas were connected to a compressed air system. A controlled valve mechanism was used to obtain increasing levels of infusion pressure. Each infusion tube was positioned in front of a manual transducer to measure force. Impact pressure was calculated using known formulas in fluid dynamics. RESULTS: The 20-gauge infusion jet showed similar impact pressure values compared with the 23-gauge infusion jet. Both showed higher levels than the 25-gauge infusion jet. This was because of the smaller jet force for the 25-gauge system. CONCLUSION: In this experimental study, both the 23- and the 20-gauge air infusion jet showed higher impact pressure values compared with the 25-gauge air infusion jet. This could be of concern regarding air infusion during 23-gauge vitrectomy since retinal damage has been shown in standard-gauge surgeries.

Reaction of tris(2-chloroethyl)phosphate with reduced sulfur species.

Tris(2-chloroethyl)phosphates (TCEP) is a widely used flame retardant in the US. It has recently been identified as one of the most frequently detected contaminants in US streams. This contaminant is of toxicological concern in sensitive coastal ecosystems such as estuaries and salt marshes. It is likely that reactions with reduced sulfur species such as polysulfides (S(n)(2-)), bisulfide (HS(-)), and thiophenolate (PhS(-)) present in anoxic subregions of coastal water bodies could have a significant impact on rates of removal of such a contaminant. The kinetics of reaction of reduced sulfur species with tris(2-chloroethyl)phosphate have been determined in well-defined aqueous solutions under anoxic conditions. Reactions were monitored at varying concentrations of reduced sulfur species to obtain the second-order rate constants from the observed pseudo-first-order rate constants. The determined second-order rate constant for the reaction of TCEP with polysulfide at 25°C is 5.0 (±1.4)×10(-4) M(-1) s(-1), with thiophenolate at 50°C is 34 (±2)×10(-4) M(-1) s(-1) and with bisulfide at 50°C is 0.9×10(-4) M(-1) s(-1), respectively. In addition, the degradation products of hydrolysis and the reactions with polysulfides, thiophenolate, and bisulfide with TCEP were studied with GC-FID and LC-MS-MS and were quantified.

Prevalence of neck pain and associated factors with personal characteristics, physical workloads and psychosocial among male rubber workers in FELDA settlement Malaysia.

UNLABELLED: Rubber tapping processes posed potential risk of various health problems among rubber workers. It ranges from simple musculoskeletal aches to more serious and complicated structural damage to bone, muscles, tendons and nerves of musculoskeletal system. These health problems might be linked directly to the arduous demands of farm labor. OBJECTIVES: A cross-sectional study was conducted to determine the prevalence of neck pain (NP) and musculoskeletal symptoms (MSS) and its association with personal characteristics, physical workloads and psychosocial factors among rubber workers. METHODS: Stratified random sampling method was adopted and a total of 419 rubber workers in FELDA's scheme Malaysia participated in this study. Data was collected through face to face interview using modified Standardized Nordic Questionnaire (SNQ) and Job Content Questionnaire (JCQ). RESULTS: The results revealed the prevalence of NP was 59.9% and weak correlation with age (?= -0.184, p= 0.001) and a positive weak correlation with working hours per day (?= 0.099, p= 0.043) significantly. All physical workloads (neck flexion or rotation, awkward postures, repetitive motion and static postures) had significant weak to moderate positive correlation with NP (p<0.05). Job insecurity was found to have weak and positive correlation with NP (p<0.05). Binary logistic regression analysis showed risk factors for NP were decreased with age (OR= 3.92, 95% CI 1.61 - 9.58, p=0.003), increase in neck flexion or rotation (OR= 9.52, 95% CI 5.55 - 16.32, p= 0.001), awkward postures (OR=2.23, 95% CI 1.29 - 3.86, p= 0.004) and static postures (OR= 1.86, 95% CI 1.10 - 3.14, p= 0.021). CONCLUSION: This study showed that high prevalence of NP was associated with neck flexion or rotation, awkward and static postures.

Critical evaluation of the claims made by pharmaceutical companies in drug promotional material in Pakistan.

BACKGROUND: In Pakistan, there is no mechanism to monitor the drug promotional campaign by pharmaceutical industry despite the fact that there is enough evidence that irrational pharmacotherapy is increasingly encountered even in the developed countries due to unethical practices of pharmaceutical promotion. Objectives. To audit the drug promotional claims made by the pharmaceutical companies in Pakistan. METHODS: Drug promotional pamphlets and brochures containing claims for the drugs, which were circulated by the pharmaceutical representatives were collected from 122 general practitioners (GPs) from Karachi and Larkana cities of the Sindh Province. The claims were critically analyzed and audited with the help of currently available evidence in the medical literature. RESULTS: 345 distinct advertisements covering 182 drugs from different manufacturers were critically analyzed for information content. Sixty two out of 345 (18%) of the reviewed advertisements were adjudged to be misleading / unjustifiable, which were again classified as, exaggerated (32%), ambiguous (21%), false (26%), and controversial (21%). The primary source of information (approximately 78%) about the newly launched drugs for the GPs was found to be the pharmaceutical representatives followed by hospital doctors (5%) and colleagues (5%). Furthermore, 110 (90%) GPs were of the view that the drug promotion has definitely an influence on their prescribing pattern. CONCLUSIONS: Since GPs in Pakistan rate pharmaceutical companies as their primary source of information regarding drugs, it can be anticipated that inappropriate advertisement claims would lead to irrational prescribing if physicians had no any other information to follow.

How fluorous is poly(2,2-bis(trifluoromethyl)-4,5-difluoro-1,3-dioxide-co-tetrafluoroethylene) (Teflon AF)?

We investigated poly(2,2-bis(trifluoromethyl)-4,5-difluoro-1,3-dioxide-co-tetrafluoroethylene (Teflon AF 2400, Tg = 240 degrees C), a stable and permeable fluorous polymer, as a transport/extraction medium for solutes for the first time. From the study of transport behavior of a series of solutes (in chloroform solution) through the film, and detailed measurement of the partitioning and diffusion of benzene in the film, we showed that the Teflon AF film is influenced by the solvent to which it is exposed. In particular, the solvent chloroform is sorbed in the film at a high concentration of 1.13 M. This plasticizes the film, so that the diffusion coefficient of benzene is about 3 orders of magnitude larger in a chloroform-equilibrated film compared to benzene coming from the gas phase into a "dry" film. The partition ratio of the polar solute 3-hydroxypyridine is dramatically higher in the case of partitioning between chloroform and a film (0.02) compared to partitioning between chloroform and the fluorous solvent FC-72 (6.7 x 10-5). Krytox FSH, a carboxylic acid terminated perfluoropolyether, plasticizes films. Tg in a 50% (w/w) film decreases to -40 degrees C. This carboxylic acid is capable of molecular recognition in the film. The noncovalent association between Krytox FSH (0.13 M in the film) and 3-hydroxypyridine increases the distribution ratio of the polar solute into the film by 41 times. In comparison, the partition ratio into a fluorocarbon solvent (FC-72) increases 15 000 times under the same conditions. As a result of imbibing organic solvent, the films of Teflon AF 2400 are not as fluorous as a fluorous liquid.