Severe acute respiratory coronavirus 2 (SARS-CoV-2) cases are overgrowing globally and now become a pandemic. A meta-analysis was conducted to evaluate the impact of age, sex, comorbidities, and ...clinical characteristics on the severity of COVID-19 to help diagnose and evaluate the current outbreak in clinical decision-making.
PubMed, ScienceDirect, and BMC were searched to collect data about demographic, clinical characteristics, and comorbidities of COVID-19 patients. Meta-analysis was conducted with Review Manager 5.3. Publication bias was assessed using Egger's test and Begg-Mazumdar's rank correlation.
Fifty-five studies were included in this meta-analysis, including 10014 patients with SARS-CoV-2 infection. Male cases and cases with an age of ≥50 years (OR = 2.41, p < 0.00001; RR = 3.36, p = 0.0002, respectively) were severely affected by SARS-CoV-2. Patients having age≥65 years are not associated (p = 0.110) with the severity of COVID-19. Presence of at least one comorbidity or hypertension, diabetes, cerebrovascular disease, cardiovascular diseases, respiratory disease, malignancy, chronic kidney disease and chronic liver diseases individually increased the severity of COVID-19 cases significantly (OR = 3.13, p < 0.00001; OR = 2.35, p < 0.00001; OR = 2.42, p < 0.00001; OR = 3.78, p < 0.00001; OR = 3.33, p < 0.00001; OR = 2.58, p < 0.00001; OR = 2.32, p < 0.00001; OR = 2.27, p = 0.0007; OR = 1.70, p = 0.003, respectively). Clinical manifestation such as fever, cough, fatigue, anorexia, dyspnea, chest tightness, hemoptysis, diarrhea and abdominal pain (OR = 1.68, p = 0.0001; OR = 1.41, p = 0.004; OR = 1.26, p = 0.03; OR = 2.38, p < 0.0001; OR = 4.30, p < 0.00001; OR = 2.11, p = 0.002; OR = 4.93, p < 0.0001; OR = 1.35, p = 0.03; OR = 2.38, p = 0.008, respectively) were significantly associated with the severity of cases. No association of severity was found with myalgia, pharyngalgia, nausea, vomiting, headache, dizziness and sore throat (p > 0.05). No publication bias was found in case of age (≥50 years, age≥65 years), comorbidities and clinical manifestations.
Males patients and elderly or older patients (age ≥50 years) are at higher risk of developing severity, whereas comorbidities and clinical manifestations could significantly affect the prognosis and severity of COVID-19.
Microbiology; Virology; Viral disease; Travel medicine; Critical care; Health informatics; Covid-19; Pneumonia; Meta-analysis; Severe; Nonsevere; Risk factor; Comorbidity; Clinical manifestation
Bangladesh positioned as third rice producing country in the world. In Bangladesh, regional growth and trend in rice production determinants, disparities and similarities of rice production ...environments are highly desirable. In this study, the secondary time series data of area, production, and yield of rice from 1969-70 to 2019-20 were used to investigate the growth and trend by periodic, regional, seasonal and total basis. Quality checking, trend fitting, and classification analysis were performed by the Durbin-Watson test, Exponential growth model, Cochrane-Orcutt iteration method and clustering method. The production contribution to the national rice production of Boro rice is increasing at 0.97% per year, where Aus and Aman season production contribution significantly decreased by 0.48% and 0.49% per year. Among the regions, Mymensingh, Rangpur, Bogura, Jashore, Rajshahi, and Chattogram contributed the most i.e., 13.9%, 9.8%, 8.6%, 8.6%, 8.2%, and 8.0%, respectively. Nationally, the area of Aus and Aman had a decreasing trend with a -3.63% and -0.16% per year, respectively. But, in the recent period (Period III) increasing trend was observed in the most regions. The Boro cultivation area is increasing with a rate of 3.57% per year during 1984-85 to 2019-20. High yielding variety adoption rate has increased over the period and in recent years it has found 72% for Aus, 73.5% for Aman, and 98.4% for Boro season. As a result, the yield of the Aus, Aman, and Boro seasons has been found increasing growth for most of the regions. We have identified different cluster regions in different seasons, indicating high dissimilarities among the rice production regions in Bangladesh. The region-wise actionable plan should be taken to rapidly adopt new varieties, management technologies and extension activities in lower contributor regions to improve productivity. Cluster-wise, policy strategies should be implemented for top and less contributor regions to ensure rice security of Bangladesh.
Nanotechnology has transformed the world with its diverse applications, ranging from industrial developments to impacting our daily lives. It has multiple applications throughout financial sectors ...and enables the development of facilitating scientific endeavors with extensive commercial potentials. Nanomaterials, especially the ones which have shown biomedical and other health‐related properties, have added new dimensions to the field of nanotechnology. Recently, the use of bioresources in nanotechnology has gained significant attention from the scientific community due to its 100 % eco‐friendly features, availability, and low costs. In this context, jute offers a considerable potential. Globally, its plant produces the second most common natural cellulose fibers and a large amount of jute sticks as a byproduct. The main chemical compositions of jute fibers and sticks, which have a trace amount of ash content, are cellulose, hemicellulose, and lignin. This makes jute as an ideal source of pure nanocellulose, nano‐lignin, and nanocarbon preparation. It has also been used as a source in the evolution of nanomaterials used in various applications. In addition, hemicellulose and lignin, which are extractable from jute fibers and sticks, could be utilized as a reductant/stabilizer for preparing other nanomaterials. This review highlights the status and prospects of jute in nanotechnology. Different research areas in which jute can be applied, such as in nanocellulose preparation, as scaffolds for other nanomaterials, catalysis, carbon preparation, life sciences, coatings, polymers, energy storage, drug delivery, fertilizer delivery, electrochemistry, reductant, and stabilizer for synthesizing other nanomaterials, petroleum industry, paper industry, polymeric nanocomposites, sensors, coatings, and electronics, have been summarized in detail. We hope that these prospects will serve as a precursor of jute‐based nanotechnology research in the future.
Jute produces the second most common natural cellulose fibers and large amounts of jute sticks as a byproduct. The main chemical composition of jute fibers and sticks, which have a trace amount of ash content, are cellulose, hemicellulose, and lignin. This makes jute an ideal candidate for utilization in nanotechnology and this review presents its latest developments and future potentials in the area.
Energy generation can be clean and sustainable if it is dependent on renewable resources and it can be prominently utilized if stored efficiently. Recently, biomass-derived carbon and polymers have ...been focused on developing less hazardous eco-friendly electrodes for energy storage devices. We have focused on boosting the supercapacitor's energy storage ability by engineering efficient electrodes in this context. The well-known conductive polymer, polyaniline (PANI), deposited on nickel foam (NF) is used as a positive electrode, while the activated carbon derived from jute sticks (JAC) deposited on NF is used as a negative electrode. The asymmetric supercapacitor (ASC) is fabricated for the electrochemical studies and found that the device has exhibited an energy density of 24 µWh/cm
at a power density of 3571 µW/cm
. Furthermore, the ASC PANI/NF//KOH//JAC/NF has exhibited good stability with ~86% capacitance retention even after 1000 cycles. Thus, the enhanced electrochemical performances of ASC are congregated by depositing PANI on NF that boosts the electrode's conductivity. Such deposition patterns are assured by faster ions diffusion, higher surface area, and ample electroactive sites for better electrolyte interaction. Besides advancing technology, such work also encourages sustainability.
In this report, we discussed rapid, facile one-pot green synthesis of gold and silver nanoparticles (AuNPs and AgNPs) by using tuber extract of
, and evaluated their antibacterial activity. AuNPs and ...AgNPs were synthesized by mixing their respective precursors (AgNO
and HAuCl
) with tuber extract of
as the bio-reducing agent. Characterization of AuNPs and AgNPs were confirmed by applying UV-vis spectroscopy, field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FTIR), and energy dispersive X-ray spectroscopy (EDS). From UV-vis characterization, surface plasmon resonance spectra were found at 530 nm for AuNPs and 446 nm for AgNPs. XRD data confirmed that both synthesized nanoparticles were face-centered cubic in crystalline nature, and the average crystallite sizes for the assign peaks were 13.3 nm for AuNPs and 22.48 nm for AgNPs. FTIR data evaluated the characteristic peaks of different phytochemical components of tuber extract, which acted as the reducing agent, and possibly as stabilizing agents. The antibacterial activity of synthesized AuNPs and AgNPs were examined in Muller Hinton agar, against two Gram-positive and four Gram-negative bacteria through the disc diffusion method. AuNPs did not show any inhibitory effect, while AgNPs showed good inhibitory effect against both Gram-positive and Gram-negative bacteria.
Electrochemical capacitors, also known as supercapacitors (SCs), have lately played an important role in energy storage and conversion systems due to their specific characteristics such as high ...strength, durability, and environmental friendliness. A wide range of materials is used as electrodes for SC applications because the electrochemical efficiency is primarily determined by the electrode materials used. Carbonaceous materials with unique surface, chemical, electrochemical, and electronic characteristics have become attractive for energy storage research, but they cannot meet the rising need for high specific energy and specific power. Besides, heteroatom‐doped carbon materials have shown pseudocapacitance characteristics and improved specific energy, specific power, and conductivity. This makes them more adaptable in SC application. Among different heteroatom doping of carbon, S‐doped carbon has gained considerable attention in SC applications due to its unpaired electrons and easily polarizable nature. S‐doped carbon materials‐based SCs have demonstrated enhanced surface wettability, improved conductivity, and induced pseudocapacitance effect, thereby delivering improved specific energy and specific power. Many reports on S‐doped carbon for SC applications have been published, but there is no specific Review on the preparation of S‐doped carbon for SC applications. This Review focuses on recent developments in the field of SC electrodes made from S‐doped carbon materials. Herein, the preparation methods and applications of S‐doped carbon for SCs were summarized following a brief discussion of different electrochemical characterization techniques of SCs. Finally, the challenges of S‐doped carbon materials and their potential prospects were discussed to give crucial insights into the favorable factors for future innovations of SC electrodes. This Review aims to provide insight for further research on the preparation of S‐doped carbon for electrochemical energy storage applications.
Supercapacitors based on S‐doped carbon materials have demonstrated enhanced conductivity, surface wettability, and induced pseudocapacitance effect, thereby delivering improved energy and power densities. This Review provides various synthetic approaches of S‐doped carbon materials and their application as supercapacitor electrodes. In particular, the effect of S‐doping on the performance of supercapacitor is discussed.
Tungsten oxide/graphene hybrid materials are attractive semiconductors for energy‐related applications. Herein, we report an asymmetric supercapacitor (ASC, HRG//m‐WO3 ASC), fabricated from ...monoclinic tungsten oxide (m‐WO3) nanoplates as a negative electrode and highly reduced graphene oxide (HRG) as a positive electrode material. The supercapacitor performance of the prepared electrodes was evaluated in an aqueous electrolyte (1 m H2SO4) using three‐ and two‐electrode systems. The HRG//m‐WO3 ASC exhibits a maximum specific capacitance of 389 F g−1 at a current density of 0.5 A g−1, with an associated high energy density of 93 Wh kg−1 at a power density of 500 W kg−1 in a wide 1.6 V operating potential window. In addition, the HRG//m‐WO3 ASC displays long‐term cycling stability, maintaining 92 % of the original specific capacitance after 5000 galvanostatic charge–discharge cycles. The m‐WO3 nanoplates were prepared hydrothermally while HRG was synthesized by a modified Hummers method.
Two dimensional nanomaterials: An asymmetric supercapacitor (ASC, HRG//m‐WO3 ASC) fabricated from tungsten oxide (m‐WO3) nanoplates as a negative electrode and highly reduced graphene oxide (HRG) as a positive electrode material attains specific capacitance of 389 F g−1 at a current density of 0.5 A g−1, with an associated high energy density of 93 Wh kg−1 at a power density of 500 W kg−1 in a wide 1.6 V operating potential window. In addition, the HRG//m‐WO3 ASC displays long‐term cycling‐stability, maintaining around 92 % of the original specific capacitance after 5000 galvanostatic charge–discharge cycles.
A novel gold nanoparticle-modified graphite pencil electrode (AuNP-GPE) is prepared just by immersing a bare GPE in AuNP solution, followed by heating for 15min. The bare and modified GPEs are ...characterized by FE-SEM imaging and cyclic voltammetry. The AuNP-GPEs showed excellent electrocatalytic activities with respect to hydrazine oxidation, with good reproducibility. To reduce the quantification and detection limits, and increase the hydrazine sensitivity, the pH and square wave voltammetry parameters are optimized. A square wave voltammetry study as a function of the hydrazine concentration showed that the AuNP-GPE detector's quantification limit was 100nmolL−1 hydrazine, much lower than the value obtained using amperometry (10µmolL−1). The limits of detection (at 3σ) for hydrazine sensing at AuNP-GPEs using square wave voltammetry and amperometry were 42nmolL−1 and 3.07µmolL−1. Finally, the modified electrode was used to determine the hydrazine concentration in drinking water, and satisfactory results are obtained. This simple, rapid, low-cost method for fabricating a modified electrode is an attractive approach to the development of new sensors.
•We developed a simple chemical method for the fabrication of AuNP-GPE.•We tested the fabricated AuNP-GPE for the detection of hydrazine using SWV and amp.•The sizes of the AuNPs on a GPE surface fell in the range of 20–85nm.•We obtained all figures of merit for the developed AuNP-GPE.•We tested the effect of potential interferences on the AuNP-GPE response.
A high-performance composite membrane for vanadium redox flow battery (VRB) consisting of ZrO2 nanotubes (ZrNT) and perfluorosulfonic acid (Nafion) was fabricated. The VRB operated with a composite ...(Nafion-ZrNT) membrane showed the improved ion-selectivity (ratio of proton conductivity to permeability), low self-discharge rate, high discharge capacity and high energy efficiency in comparison with a pristine commercial Nafion-117 membrane. The incorporation of zirconium oxide nanotubes in the Nafion matrix exhibits high proton conductivity (95.2 mS cm−1) and high oxidative stability (99.9%). The Nafion-ZrNT composite membrane exhibited low vanadium ion permeability (3.2 × 10−9 cm2 min−1) and superior ion selectivity (2.95 × 107 S min cm−3). The VRB constructed with a Nafion-ZrNT composite membrane has lower self-discharge rate maintaining an open-circuit voltage of 1.3 V for 330 h relative to a pristine Nafion membrane (29 h). The discharge capacity of Nafion-ZrNT membrane (987 mAh) was 3.5-times higher than Nafion-117 membrane (280 mAh) after 100 charge-discharge cycles. These superior properties resulted in higher coulombic and voltage efficiencies with Nafion-ZrNT membranes compared to VRB with Nafion-117 membrane at a 40 mA cm−2 current density.
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•The Nafion-ZrNT composite membrane was successfully fabricated.•Nafion-ZrNT membrane shows low vanadium-ion crossover thus superior ion selectivity.•VRB showed low self-discharge rate for Nafion-ZrNT composite membrane than Nafion-117.•Nafion-ZrNT exhibits high discharge capacity and efficiency compared with Nafion-117.
The fabrication of eco-benign, low cost, and high-performance supercapacitors comprising hierarchical porous electrodes and superior electrolytes are crucial for effective energy storage. In this ...study, a comparison of electrochemical performances between jute sticks derived activated carbon (JC) and commercially available activated carbon (AC) based symmetric supercapacitors was carried out. We developed highly effective porous activated hierarchical carbon nanosheets through the pyrolysis of abundantly available jute sticks. Electrochemical double-layer supercapacitor devices were assembled utilizing JC and AC based electrodes with glycerol-based bio-electrolyte. The developed JC-based supercapacitor exhibit a negligible IR drop compared to the AC-based supercapacitor, attributed to low charge transfer resistance in the prepared JC. The results showed that the JC-based supercapacitor provides higher specific capacitance (150 F/g) than the AC-based supercapacitor (29 F/g) at a scan rate of 10 mV/sec. The JC-based supercapacitor illustrates a specific energy density of 20 Wh/kg at a specific power density of 500 W/kg with fabulous performance after 10,000 charge/discharge cycles. The series and parallel connection tests demonstrate a stable behavior and indicate that the specific capacitance and operating potential windows of the JC-based supercapacitor can be tuned. In addition, the fabricated JC-based supercapacitor shows mechanical robustness at different bending positions. Our findings confirm that the processed bio-waste shows promise as energy storage materials.
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•Natural jute sticks derived activated carbon as supercapacitor material.•Conductive agents-free electrodes.•Glycerol-based bio-electrolyte.•The supercapacitor device delivers energy density of 20 Wh/kg and retains high cyclic stability.•Design of bendable electrodes with mechanical robustness.
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