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The ligand, N,N'-bis(salicylidine)ethylenediamine or salen (L), and its complexes 1-3 with Ni(II), Cu(II) and Mn(II) were synthesized. Various analytical methods such as microanalysis, 1H-NMR, 13C-NMR, ESI-MS and FT-IR spectroscopy has been used to characterize the synthesized compounds. Antibacterial activity of the prepared compounds were tested against two Gram-positive bacteria Staphylococcus aureus and Bacillus subtillus and two Gram-negative bacteria Pseudomonas aeroginosa and Escherichia coli by agar well diffusion method. Antibacterial screening results indicate that the metal compounds are more biologically active than the free ligand. The variation of metal ions appears to influence their antibacterial activity toward different organisms. The mode of action of the synthesized metal complexes as antibacterial agents have also been explained.

Aim: A novel design for non-reversible as well as reversible parity generator and detector in Quantum-dot Cellular Automata (QCA) technology is presented in this research article. Parity generator and detector circuits are reliable error-checking components of a nano-communication system. Objective: The main focus of this research is to design an ultra-low-power fault-tolerant reversible gate implementation of the parity logic function in QCA. An efficient QCA design layout with minimal area, less latency and the least energy dissipation is desired. Methods: The proposed designs are developed using Quantum-dot Cellular Automata (QCA) technology. The circuits are optimized using majority gate reduction and clock zone reduction techniques. Also, the cell-cell interaction technique is employed to further optimize the QCA circuit. To increase the fault tolerance and ultra-low power operation, reversible QCA circuits are designed using cascaded Feynman gates. Results Conclusion: The efficiency of the parity generator and detector is calculated to be more than 25% compared to existing QCA layouts. It is demonstrated in this paper that the proposed circuits perform exceptionally well on every design parameter. The design parameters under consideration are cell count, cell area, complexity, crossover count, latency and energy dissipation. Conclusion: Using reversible logic, a fault-tolerant and defect-sensitive circuit are developed for parity generation and detection.

The research on jute fiber reinforced polymer composites is an emergent concern with the development of new materials due to their significant properties like economical, partially biodegradable, and environment friendly. It is wondered that the hydrophilic nature of jute fiber negatively affects the interfacial interaction with hydrophobic polymeric materials in the composite, which then affects the resultant mechanical, microstructural and physico-chemical absorption properties. In order to overcome this fact, researchers have carried out some techniques for fiber surface chemical treatments. On the other hand, due to the low processing costs and design flexibility, thermoplastics deal many benefits over thermoset polymers, and polyethylene shows excellent processing behaviors such as low density, low cost, considerable flex life, outstanding surface hardness, scratch resistance and good electrical insulator. Besides the traditional thermoplastic and thermosetting polymers, montmorillonite nanoclay is also receiving attention to manufacturing fiber polymer nanocomposites for industrial and household applications as well. This review is considered to highlight the progress of jute fiber reinforced polymer nanocomposites. The study also focuses on the several features of jute polymer composites and nanocomposites as a function of fiber chemical treatments.

COVID-19’s outbreak affected and compelled people from all walks of life to self-quarantine in their houses in order to prevent the virus from spreading. As a result of adhering to the exceedingly strict guideline, many people developed mental illnesses. Because the educational institution was closed at the time, students remained at home and practiced self-quarantine. As a result, it is necessary to identify the students who developed mental illnesses at that time. To develop AiPsych, a mobile application-based artificial psychiatrist, we train supervised and deep learning algorithms to predict the mental illness of students during the COVID-19 situation. Our experiment reveals that supervised learning outperforms deep learning, with a 97% accuracy of the Support Vector Machine (SVM) for mental illness prediction. Random Forest (RF) achieves the best accuracy of 91% for the recovery suggestion prediction. Our android application can be used by parents, educational institutes, or the government to get the predicted result of a student’s mental illness status and take proper measures to overcome the situation.

Early identification of COVID-19 is critical for preventing death and significant illness. People living in remote parts of resource-constrained countries find it more difficult to get tested due to a lack of adequate testing. As a result, having a primary filtering tool that can assist us in simplifying bulk COVID testing to prevent community spread is vital. In this paper, we introduce CovFilter, a low-cost portable device for COVID-19 prediction for resource-constrained rural communities, with the goal of encouraging people to be tested for COVID-19 in a more informed manner. CovFilter Hardware Module collects health parameters from three sensors while the CovFilter Prediction Module predicts COVID-19 status using the health data. We train supervised learning algorithms and an artificial neural network to predict COVID-19 from vital sign readings where MultilayerPerceptron outperformed ANN, NaiveBayes, Logistic, SGD, DecisionStump, and SVM with an F1 of 93.22%. We further show that a weighted majority voting ensemble classifier can outperform all single classifiers achieving an F1 of over 94%.

Estimation of antibody development against SARS-CoV-2 is essential means for understanding the immune response against the virus. We reported IgG antibody development status against Nucleocapsid protein of the virus and compared with lifestyle (health and food habits), co-existing diseases, vaccination and COVID-19 infection status. ELISA (Enzyme Linked Immunosorbent Assay) was performed to assess IgG antibodies targeted against the Nucleocapsid protein of SARS-CoV-2 in participants (n=500). In this seroprevalence study, serological data were estimated for a period of 10 months in the participants who were aged 10 years and above. Sociodemographic and risk factors related data were collected through a written questionnaire and chi-square test was performed to determine the association with seropositivity. The overall seroprevalence of anti-SARS-CoV-2 antibodies among the study subjects was 47.8%. Estimates were highest among the participants of 21-40 years old (55.1%), and lowest in older aged (>60 years) participants (39.5%). Among the Sinopharm vaccinated individuals 81.8% had developed anti-Nucleocapsid antibody. Physical exercise and existence of comorbidities like hypertension and diabetes were the distinguishing factors between seropositive and seronegative individuals. Seropositivity rate largely varied among symptomatic (67%) and asymptomatic (33.1%) COVID-19 infected participants. The findings suggest that residents of Dhaka city had a higher prevalence of anti-nucleocapsid antibody in the second year of the pandemic. This indicates the improvement of immunological status among the population. Finally, the study emphasizes on maintaining active and healthy lifestyle to improve immunity. However, the absence of IgG antibodies in many cases of COVID-19 infected individuals suggests that antibodies wane with time.Key messagesThe overall seroprevalence of anti-Nucleocapsid IgG among the study subjects was determined to be 47.8%.Age, regular physical exercise, existence of comorbidities were the identified parameters associated with seroprevalence.This study observed lower prevalence of Anti-Nucleocapsid antibody among asymptomatic cases of COVID-19 infected individuals compared to symptomatic cases.

A new Schiff base Co(II) complex and - peroxo complex were synthesized and characterized by thin layer chromatography (TLC), elemental analyses, magnetic moment, conductivity measurements, UV-Vis., IR and ESI-MS spectral studies. The cobalt ion was participated in direct complexation with the Schiff base (SB) ligand derived from o-aminobenzoic acid and cinnamaldehyde during the single pot reaction. IR spectral data showed that the Schiff base ligand coordinated to the metal ion through nitrogen of azomethine group and oxygen of carboxyl group (COO-). The molar conductance values indicated that both the complexes are non-electrolytic in nature. Antibacterial activity of the complexes was tested against four pathogenic bacteria namely Staphylococcus aureus, Bacillus cereus, Escherichia coli & Shigella dysenteriae with standard Kanamycin-30. The results showed that both type of complexes have moderate to strong antibacterial activity and the peroxo complex is relatively more potential towards all the tested organisms.

Zr (IV) and Sn (II) complexes were prepared with bidentate ligand, benzyl 2-(3-phenylallylidene) hydrazinecarbodithioate, derived from the condensation of S-benzyldithiocarbazate (SBDTC) with cinnamaldehyde and characterized by microanalysis, molar conductance and magnetic measurements, IR, electronic and ESI-MS studies. It was found that the ligand coordinated to the metal center through azomethine nitrogen and thiol sulfur atoms to form octahedral complexes with both the metal ions. The antimicrobial activities of the ligand and its complexes were investigated against the gram-positive and gram-negative bacteria and the fungus strain. The metal complexes showed strong activity than the free ligand.

A Schiff base ligand derived from condensation of S-benzyldithiocarbazate (SBDTC) and salicylaldehyde, and its U(VI), Th(IV) and Zr(IV) complexes have been synthesized. The compounds are characterized by elemental analysis, molar conductance, magnetic moments, UV-Vis, FT-IR and 1H NMR spectra. The Schiff base ligand coordinates via azomethine nitrogen, thiol sulfur and/or the phenolic OH group, and acts as bidentate in case of U(VI) and Zr(IV) ions and tridentate with Th(IV) ion. The U(VI) and Th(IV) complexes are 1 : 2 electrolytes whereas Zr(IV) complex is non-electrolytic. All the compounds have been tested for their antibacterial activity against four pathogenic bacteria, two Gram-negative Escherichia coli and Shigella dysenteriae and two Gram-positive Staphylococcus aureus and Bacillus subtilis using Kanamycin (K-30) as a standard. The U(VI) and Th(IV) complexes exhibit stronger antibacterial activity than the Zr(IV) complex against all tested organisms.

Eight new peroxo complexes of the type [MO(O2)(Asp)L] have been synthesized and characterized by conductivity, magnetic moments, UV-Vis, IR, ESI-MS and 1H NMR spectra, TLC, and elemental analyses [M = Th(IV) and Zr(IV), Asp= deprotonated aspartic acid, L = quinoline, isoquinoline, 8-hydroxyquinoline, and 1,10-phenanthroline]. IR spectra indicate that the ligands coordinate to the metal ions via nitrogen of the amino group of aspartic acid and heterocyclic amines, oxygen of the carboxylate group of deprotonated aspartic acid and the peroxo group (O–O). ESI-MS spectral data and magnetic moment values coupled with electronic spectral data suggest an octahedral geometry for all the complexes. The molar conductance values indicate that all the complexes behave as 1 : 2 electrolytes except complexes of 8-hydroxyquinoline that behaves as 1 : 3 electrolytes. Antibacterial activity of the complexes has been tested against four pathogenic bacteria, two Gram-positive Staphylococcus aureus and Bacillus subtilis and two Gram-negative Escherichia coli and Shigella dysenteriae using Kanamycin (K-30) as a standard. The MIC values for complexes hve been measured. Antifungal activity of the complexes has been tested against four pathogenic fungi Aspergillus flavus, Penicillium species, Candida species, and Aspergillus niger using Fluconazole-50 as a standard. The complexes K2[ThO(O2)(Asp)(IQ)] and K2[ZrO(O2)(Asp)(Q)] demonstrate the highest antibacterial activity, and K2[ZrO(O2)(Asp)(1,10-Phen)] exhibits the highest antifungal activity against all the tested pathogens.

In this study, jute polyethylene clay nanocomposites were developed using hot press technique. The hydrophilic nature of fiber and nanoclay exhibited poor interfacial interaction to hydrophobic polymer matrix. In order to enhance the interfacial interaction among fiber, polymer, and nanofillers, the chemically treated jute (with benzenediazonium salt, propionic anhydride, and 3-isocyanatopropyltriethoxy silane) and organically modified nanoclay were used for the manufacturing of nanocomposites in this study. The effect of chemical treatments and nanoclay addition on the improvement of absorption characterizations of prepared nanocomposites against water and few chemical reagents have been investigated. It has been observed that the treated jute composites showed higher improvement in absorption properties than raw jute composite and silane treated jute composite found highest value. In addition, nanoclay filled composites showed higher improvement than composite without nanoclay and MMT-1.31PS nanoclay loaded nanocomposite exhibited highest improvement among five types of MMT nanoclay used in this work. The fabricated nanocomposites were resistant to all chemicals used except carbon tetrachloride.

Two new peroxo-complexes of Cd(II) and Zr(IV) ion containing Schiff base (SB) were synthesized and characterized by Thin Layer Chromatography (TLC), Elemental analyses, conductivity, magnetic moment measurements, UV-Vis. and FT-IR spectral studies. The Schiff base ligand derived from cinnamaldehyde and o-aminophenol participated in complexation through a single pot reaction. FT-IR spectra showed that the Schiff base ligand coordinated to the metal ion through nitrogen of azomethine group and oxygen of hydroxyl group & peroxo group (O-O). The molar conductance values indicated the non-electrolytic nature of both the complexes. Antibacterial activity of the complexes was tested against four pathogenic bacteria, two Gram-positive Staphylococcus aureus & Bacillus cereus and two Gram-negative Escherichia coli & Shigella dysenteriae with standard Kanamycin-30. The result showed that Cd(II) complex exhibited more potential antibacterial activity than the Zr(IV) complex against all the tested pathogens.

Two new peroxo complexes of Cu(II) and Ni(II) ion containing Schiff base (SB) were synthesized and characterized by TLC, Elemental analyses, conductivity, magnetic moment measurements, UV-Vis. and IR and ESI-MS spectral studies. The Schiff base ligand derived from cinnamaldehyde and o-aminophenol participated in complexation through a single pot reaction. IR spectra showed that the Schiff base ligand coordinated to the metal ion through nitrogen of azomethine group and oxygen of hydroxyl group & peroxo group (O-O). Magnetic moment value coupled with electronic spectral data suggested a square planar geometry for both the complexes. The molar conductance values indicated the non-electrolytic nature of the complexes. Antibacterial activity of the complexes was tested against four pathogenic bacteria, two Gram-positive Staphylococcus aureus & Bacillus cereus and two Gram-negative Escherichia coli & Shigella dysenteriae with Kanamycin (K-30) standard. The result shows that Cu(II) complex exhibited more potential antibacterial activity than the Ni(II) complex against all the tested organisms.

The jute polyethylene composites were developed using the hot-press technique with different fiber weight ratios. Due to the hydrophilic nature of fiber, it exhibited poor interfacial interaction to hydrophobic polymer matrix. In order to enhance the interfacial interaction between fiber and polymer, the benzene diazonium salt (BDS), propionic anhydride (PA), and 3-isocyanatopropyl triethoxysilane (silane) treated jute were used for the manufacturing of composites in this study. The chemical resistance tests of prepared composites were performed in order to probe whether these are resistant to various chemicals such as: acids, alkalis, and solvents. The effect of chemical treatments of the composites have been investigated. It was observed that the fabricated composites were resistant to all chemicals except carbon tetrachloride. The treated jute composites showed higher chemical resistance than raw jute composite and silane treated jute composite yield the highest resistance which can be suggested for making the water and chemical storage tanks.

In this study, raw wood (RW) samples were impregnated with a mixture of furfural alcohol (FA), styrene (ST), and nanoclay of varying concentration of FA and ST. These impregnated wood and RWsamples were then subjected to FTIR, water uptake (WU), and thermal studies. The FT-IR results at 1600-1800 cm-1showed that the ST/FA/clay-WPNCs had different peak numbers with different positions compared with the RW. So, there was an interaction between RW, FA, ST and clay. The WU of ST/FA/clayimpregnated wood is lower than RW. In thermo gravematric result, below 100 °C the impregnated wood samples had less weight lost compared to RW.

The metal (II) complexes, Na2[ML2] [M = Cu, Co, Ni, and Zn], of salicylaldehyde thiosemicarbazone (L) containing a trifunctional ONS-donor system have been synthesized and characterized on the basis of physicochemical data by elemental analysis, magnetic moment, molar conductance, and spectroscopic (electronic, IR and ESI-MS). The ligand functions as ONS tridentates producing octahedral complexes. All compounds showed significant antibacterial activity in different ranges against gram positive (Bacillus subtillus) and gram negative (Escherichia coli) bacteria.

The ligand, L is the Schiff base formed by condensation of 1- naphthaldehyde with semicarbazide and its Cu(II) complex have been synthesized and characterized by elemental and thermogravimetric analysis and molar conductivity, magnetic and spectroscopic measurements. Elemental analysis of the chelate suggests the stoichiometry is 1:1 (metal-ligand). Infrared spectra of the complex agree with the coordination to the central metal atom through the nitrogen of the azomethine (-HC=N-) group and the carbonyl oxygen atom. Magnetic susceptibility data suggest a tetrahedral geometry for the complex. ESI-MS data also supports the proposed structure of the synthesized compounds. The ligand and its copper complex have been screened for their antibacterial activity against Enterobacter aerogenes and Bacillus cereus. The metal complex were shown to possess more antibacterial activity than the uncomplexed ligand.

Five new oxovanadium (IV) complexes have been synthesized from two mixed ligand, 5,6-Dimethyl-1,10-phenanthroline and amino acid derived Schiff bases containing salicylaldehyde. All the synthesized complexes were characterized by some physicochemical properties, molar conductance, magnetic susceptibilities measurements, elemental analysis, UV-Visible and IR spectral studies. The molar conductance values reveal the non-electrolytic nature of the complexes. The magnetic moment values indicate that the complexes are paramagnetic in nature. IR spectral data indicates the coordination of tridentate amino acid Schiff base ligands to the vanadyl (VO2+) ion through O, N, Odonor. ESI-MS spectral data confirms the proposed molecular formula of the complexes. All the analytical data suggested that all the complexes possess to have distorted octahedral geometry. Antibacterial activity of the complexes was tested against two Gram positive bacteria Escherichia coli and Pseudomonas aeruginosa and two Gram negative bacteria Staphylococcus aureus and Bacillus cereus with Kanamycin (K-30) standard. The result shows that all the complexes possess to have moderate to strong potential antibacterial activity against all the tested pathogenic bacteria.

Acetylacetonate containing Schiff base and their metal complexes has a wide range of applications in microbiology as anti-microbial agents, the chemical industry as catalyst, and is an important chemical in cancer treatement. The extra-ordinary ligating properties of acetylacetonate enable them to form a large number of complex compounds with transition metals, a vast majority of which find abundant applications in potential areas. This has stimulated researchers to explore novel applications of the synthesized ligands and the metal complexes thereof. This review presents a report of the studies on the biological activities, anticancer properties, and catalytic activities of acetylacetonate and their metal complexes.

The salophen ligand and its complexes of Ni(II), Co(II), Cu(II), and Mn(II) are explored in terms of synthesis, conductivity; magnetic measurements, elemental analysis, FT-IR; electronic spectra, and antibacterial activities. The 3D molecular modeling structures of the ligand and its metal complexes are obtained by using Argus lab software. The experimental data shows that the ligand is tetradentate and bonded to the metal ion via N2O2 donor atoms. Antibacterial activity of the synthesized compounds are checked against the microbes Bacillus cereus and Escherichia coli. The metal complexes exhibit antibacterial activity higher than that of the free ligand. This works contributes to the science of Schiff base compounds, in addition to stimulating the synthesis of new ligands and its complexes for the future advancement of coordination chemistry.

Nowadays, the socioeconomic status has been changed a lot, so people are now more concerned about their life style and health. They have knowledge about the detrimental effects of synthetic products. That is why they are interested in natural products. Utilization of natural products of plant origin having fewer side effects has gained popularity over the years. There is immense scope for natural products that can intimate health benefits beyond traditional nutrients. Moringa oleifera is one such tree having tremendous nutritional and medicinal benefits. It is rich in macro- and micronutrients and other bioactive compounds which are important for normal functioning of the body and prevention of certain diseases. Leaves, flowers, seeds, and almost all parts of this tree are edible and have immense therapeutic properties including antidiabetic, anticancer, antiulcer, antimicrobial, and antioxidant. Most of the recent studies suggested that Moringa should be used as a functional ingredient in food. The aim of this review is to focus the use of Moringa oleifera as a potential ingredient in food products.

Limited information is available regarding the effects of arsenic exposure on immune function. We have recently reported that chronic exposure to As was associated asthma, as determined by spirometry and respiratory symptoms. Because T helper 2 (Th2)-driven immune responses are implicated in the pathogenesis of allergic diseases, including asthma, we studied the associations of serum Th1 and Th2 mediators with the As exposure markers and the features of asthma among individuals exposed to As. A total of 553 blood samples were selected from the same study subjects recruited in our previous asthma study. Serum levels of Th1 and Th2 cytokines were analyzed by immunoassay. Subjects' arsenic exposure levels (drinking water, hair and nail arsenic concentrations) were determined by inductively coupled plasma mass spectroscopy. Arsenic exposure levels of the subjects showed significant positive associations with serum Th2-mediators- interleukin (IL)-4, IL-5, IL-13, and eotaxin without any significant changes in Th1 mediators- interferon-γ and tumor necrosis factor-α. The ratios of Th2 to Th1 mediators were significantly increased with increasing exposure to As. Notably, most of the Th2 mediators were positively associated with serum levels of total immunoglobulin E and eotaxin. The serum levels of Th2 mediators were significantly higher in the subjects with asthma than those without asthma. The results of our study suggest that the exacerbated Th2-driven immune responses are involved in the increased susceptibility to allergic asthma among individuals chronically exposed to As.

The jute polyethylene nanocomposites were manufactured using the hot-press technique with different fiber weight fractions. The hydrophilic nature of fiber exhibited poor interfacial interaction to hydrophobic polymer matrix. Three types of chemical reagents such as: benzenediazonium salt (BDS), propionic anhydride (PA), and 3-isocyanatopropyl triethoxysilane (Silane) have been used to reduce hydrophilicity of jute fibers. The chemical resistance tests of prepared composites were performed in order to observe whether these composites are resistant to various chemicals such as: acids, alkalis, and solvents. It was observed that the fabricated composites were resistant to all chemicals except carbon tetrachloride. The treated jute composites showed higher chemical resistance than raw jute composite and silane treated jute composite gave the highest resistance which can be suggested for making the water and chemical storage tanks.

Five oxovanadium(IV) complexes of the type [VO(L)(DPhen)], containing Schiff base derived from α-amino acid, [where L = 3-hydroxybenzaldehyde-α-alanine (hb-Ala), 3-hydroxybenzaldehyde-DL-phenylalanine (hb-Phe), 3-hydroxybenzaldehyde-leucine (hb-Leu), 3-hydroxybenzaldehyde-glycine (hb-Gly) and 3-hydroxybenzaldehyde-DL-methionine (hb-Met) & DPhen = 5,6-Dimethyl-1,10-phenanthroline] have been synthesized and characterized by some physicochemical properties, molar conductance, magnetic susceptibilities measurements, elemental analysis, UV-Visible, FT-IR and EIS-MS spectral studies. The molar conductance values evidenced the non-electrolytic nature of the complexes. The magnetic moment values of the complexes are in accordance with the d1 electronic configuration of the VIVO2+ moiety and indicates the paramagnetic behavior of the complexes. IR spectral data indicates the coordination of tridentate amino acid Schiff base ligands to the vanadyl (VO2+) ion through O, N, O-donor. ESI-MS spectral study confirmed the proposed structure of the complexes. All the analytical data suggested that all the complexes possess to have distorted octahedral geometry. The complexes were screened for their antibacterial activity against four human pathogenic bacteria; two Gram positive Escherichia coli & Pseudomonas aeruginosa and two Gram negative Staphylococcus aureus & Bacillus cereus with Kanamycin (K-30) standard. The result shows that all the complexes have moderate to strong potential antibacterial activity against all the pathogenic bacteria. This work is licensed under a Creative Commons Attribution 4.0 International License.

Background A large body of evidence has shown a link between arsenic exposure and diabetes, but the underlying mechanisms have not yet been clarified. Objective We explored the association between arsenic exposure and the reduction of skeletal muscle mass as a potential mechanism of insulin resistance for developing arsenic-related hyperglycemia. Methods A total of 581 subjects were recruited from arsenic-endemic and non-endemic areas in Bangladesh and their fasting blood glucose (FBG), serum insulin, and serum creatinine levels were determined. Subjects’ arsenic exposure levels were assessed by arsenic concentrations in water, hair, and nails. HOMA-IR and HOMA-β were used to calculate insulin resistance and β-cell dysfunction, respectively. Serum creatinine levels and lean body mass (LBM) were used as muscle mass indicators. Results Water, hair and nail arsenic concentrations showed significant positive associations with FBG, serum insulin and HOMA-IR and inverse associations with serum creatinine and LBM in a dose-dependent manner both in males and females. Water, hair and nail arsenic showed significant inverse associations with HOMA-β in females but not in males. FBG and HOMA-IR were increased with the decreasing levels of serum creatinine and LBM. Odds ratios (ORs) of hyperglycemia were significantly increased with the increasing concentrations of arsenic in water, hair and nails and with the decreasing levels of serum creatinine and LBM. Females’ HOMA-IR showed greater susceptibility to the reduction of serum creatinine and LBM, possibly causing the greater risk of hyperglycemia in females than males. Path analysis revealed the mediating effect of serum creatinine level on the relationship of arsenic exposure with HOMA-IR and hyperglycemia. Conclusion Arsenic exposure elevates FBG levels and the risk of hyperglycemia through increasing insulin resistance with greater susceptibility in females than males. Additionally, arsenic exposure-related reduction of skeletal muscle mass may be a mechanism underlying the development of insulin resistance and hyperglycemia.

Widespread contamination of arsenic (As) has become a global public health concern. Exposure to As causes respiratory complications. Asthma, a major respiratory complication, is increasing worldwide. However, the effect of chronic As exposure on the risk of asthma remains to be clarified. This study aims to examine the associations between As exposure (water, hair and nail As) and the risk of asthma among 842 individuals exposed to a wide range of As concentrations through drinking water in Bangladesh. Subjects' As exposure levels were measured with ICP-MS. Lung function was examined by a handheld spirometer. Characteristic features of asthma were evaluated by bronchodilator-mediated reversibility in airway obstruction and asthma-like symptoms through a structured questionnaire. Total serum immunoglobulin E (sIgE) levels were measured by immunoassay. As exposure metrics showed inverse associations with lung function measures (FEV1, FEV6, and FEV1/FEV6 ratio) and positive associations with the risks of airway obstruction (AO), reversible airway obstruction (RAO), and asthma-like symptoms. The majority of AO patients (70 of 97) were RAO with one or more characteristic symptoms of asthma. Intriguingly, subjects' As exposure levels showed positive associations with total sIgE levels. Total sIgE in RAO patients was significantly (p 0.001) higher than that in the control group. Thus the results revealed that chronic As exposure was associated with the risk of the characteristic features of asthma. Additionally the association between As exposure and subjects' total sIgE levels and an elevated level of total sIgE in RAO group suggested that As exposure-related asthma might be allergic in nature.

Nanoclay is considered potential nanofiller for the manufacturing of natural fiber nanocomposites. The hydrophilic nature of natural fibers affects negatively its adhesion to hydrophobic polymer matrix. In the present study, propionic anhydride (PA) treated jute were used for the manufacturing of jute/polyethylene/nanoclay nanocomposites. Different amount (wt%) of montmorillonite (MMT) were used as nanofiller in order to optimize the nanoclay in the composite system. Finally, the nanocomposites were prepared using hot press machine at 5, 10, 15, and 20 wt% fiber loadings. Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), tensile tests, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and chemical resistance test were used to evaluate the morphological, thermo-mechanical and chemical resistance properties of the composites.

In this study, jute cellulose/polyethylene (PE) biocomposites were prepared using a hot press machine. Silica and nanoclay act as reinforcing agents in the composite system. The effects of clay and silica addition on the mechanical, thermal, and morphological properties of jute cellulose/PE biocomposites with different fiber loadings (5, 10, 15, and 20 wt %) were investigated. The biocomposites were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, and thermogravimetric analysis. The mechanical properties were investigated using a universal testing machine. From FTIR results, it indicates that the CO stretching vibration had disappeared, while the intensity of peaks at 1718 and 1716 cm−1 appeared after addition of silica. The better interfacial bonding between jute cellulose/PE/silica biocomposites are reflected in the enhancement of the mechanical properties as well as thermal stability. The tensile strength and modulus had shown the highest values as well as higher activation energy for thermal decomposition. The surface area analysis result showed that the jute cellulose/PE/silica biocomposites have higher surface area and pore volume with less pore size. The manufactured biocomposites can be used in interior and exterior applications as well as a construction material.

Yellowtail catfish, Pangasius pangasius namely deshi pangas is one of the major important native species of Bangladesh. It was available in most rivers of Bangladesh in last two decades. Recently, IUCN Red List of Bangladesh has categorized P. pangasius as an endangered species. To save this species from endangered situation, a sequential experiment was conducted on induced breeding to optimize the hormonal doses of pituitary gland (PG). In this regards, three treatments (double doses administered for female viz. 2 + 8 mg PG/kg, 1.5 + 8.0 mg PG/kg and 2 + 10 mg PG/kg body weight in T1, T2 and T3, respectively whereas single dose for male viz. 2 mg PG/kg, 1.5 mg PG/kg and 2 mg PG/kg body weight in T1, T2 and T3, respectively) have been conducted for induced breeding of P. pangasius. Twelve brood fishes (6 males: 6 females) were used in each treatments for induced breeding of P. pangasius and successfully responded at the age of 4.5+ year of its life, breeds between July and August with a peak in August. Highest ovulation rate (100%), fertilization rate (30.0 ± 0.3%), hatching rate (24.8 ± 0.7%) and survival rate (47.0 ± 12.3% after 72 h) of P. pangasius were found in T3. However, there was no larvae hatched in T1 and a negligible number of larvae hatched in T2 (0.7 ± 0.1%) and died shortly. In larval growth of P. pangasius, the average weight was found 2.0 ± 0.1, 4.4 ± 0.1, 6.9 ± 0.3, 10.1 ± 1.1, 16.4 ± 1.7, 45.5 ± 2.8 and 66.7 ± 3.2 g after rearing in nursery pond at 5, 10, 20, 30, 60, 90 and 120 days, respectively. The findings of the present study have disclosed the first success in induced breeding as well as larval rearing of P. pangasius.

Wood impregnated with styrene (ST) has a greater hydrophobicity than raw wood. Organically modified nanoclay can be used as a filler to increase the interfacial interaction between wood and ST. Raw wood shows an improved micro-structure, water uptake, modulus of rupture (MOR), modulus of elasticity (MOE), and thermal properties after impregnation with a mixture of i) non-branched organic ammonium-modified nanoclay (R-NH3+-clay) and ST; and ii) branched organic ammonium-modified nanoclay ((R)2N+(CH3)2-clay) and ST. Styrene with R-NH3+-clay-impregnated wood had a higher water uptake than the ST with (R)2N+(CH3)2-clay-impregnated wood. The MOE and MOR values of the ST with R-NH3+-clay-impregnated wood were higher than the ST with (R)2N+(CH3)2-clay-impregnated wood. Below 250 °C, the(R)2N+(CH3)2-clay with ST-impregnated wood had a greater thermal stability than the R-NH3+-clay with ST-impregnated wood.

In this study, (jute fiber)/polyethylene biocomposites were prepared by using a hot press machine. Jute fiber was investigated as a reinforcing filler material for producing structural composites with better environmental performance. The effects of clay and silica addition on the physical, mechanical, and thermal properties of (jute fiber)-reinforced polyethylene biocomposites with different fiber loadings (5, 10, 15, and 20 wt%) were investigated. The biocomposites were characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis. The composite surface area and pore volume were determined by using the Brunauer-Emmett-Teller equation. The mechanical properties were investigated by using a Universal Testing Machine. Because of Si-O-Si stretching vibration, the O-H group from 3,200 to 3,400 cm−1 disappeared. The scanning electron microscopy results proved that a significant difference among the composites was present due to the interfacial bonding between the fiber and the matrix.

Poly(vinyl alcohol)/silica/clay (PVA-si-clay) and poly(vinyl alcohol)/(fumed silica)/clay (PVA-fsi-clay) nanocomposites were prepared via solution intercalation by exploiting phase separation based on the bridging of particles by polymer chains. Both nanocomposites were characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, adsorption isotherm (Brunauer-Emmett-Teller model [BET]), X-ray fluorescence, thermogravimetric analysis, and tensile testing. The Fourier-transform infrared spectroscopy indicated that the PVA-si-clay (1.28E) nanocomposite had a much broader peak compared with other nanocomposites. The PVA-si-clay (1.28E) nanocomposite contained the highest percentage of silicon group compared with other nanocomposites. According to the results of the scanning electron microscopy, clay (1.28E) showed better compatibility with the PVA-si matrix followed by clay (1.30E) with PVA-fsi matrix. The results of the Brunauer-Emmett-Teller model showed PVA-si-clay (1.28E) and PVA-fsi-clay (1.30E) nanocomposites had a higher surface area and average pore volume with a smaller pore size. The hydroxyl-functionalized PVA compatibilizer enhanced the mechanical properties as well as the thermal properties because of a higher level of interaction between the hydroxyl groups of PVA, the silanol groups of silica phase, and the modified clay.

The thermal behavior of chemically modified jute fiber-reinforced polyethylene (PE) nanocomposites was investigated. Nanocomposites were prepared by hot press molding technique using different fiber loadings (5, 10, 15, and 20 wt%) for both treated and untreated fibers. Jute fibers were chemically modified with benzene diazonium salt to increase their compatibility with the PE matrix. Surface and thermal properties were subsequently characterized. Fourier transform infrared spectroscopy and scanning electron microscopy analysis were used to study the surface morphology. Thermogravimetric analysis (TGA) and differential scanning calorimetry were carried out for thermal characterization. Fourier transform infrared spectroscopy and scanning electron microscopy study showed interfacial interaction among jute fiber, PE, and nanoclay. It was observed that, at optimum fiber content (15 wt%), treated jute fiber-reinforced composites showed better thermal properties compared with that of untreated ones and also that nanoclay-incorporated composites showed enhanced higher thermal properties compared with those without nanoclay. POLYM. COMPOS., 38:1266–1272, 2017. © 2015 Society of Plastics Engineers. © 2015 Society of Plastics Engineers

This book chapter gives an overview of metal, ceramic, and polymer-based nanocomposites, including incorporation of CNTs—three different kinds of nanocomposites. Based on the clay dispersed nanocomposites, the physical, mechanical, thermal, morphological, and optical properties were evaluated. The FTIR analysis proved that nanoclay/polypropylene nanocomposites were made in order to improve the water uptake resistance. The tensile strength of nanoclay-based nanocomposite is greatly improved by increasing the percentage loading of nanoclay to polypropylene. Polymer layered silicate (PLS) improved the nanocomposites’ properties compared with the pure polymer and conventional micro and macrocomposites, and it showed the high moduli, strength and heat resistance, decreased flammability and gas permeability, and increased biodegradability. The enhancement of thermal stability of the nanoclay based nanocomposites is achieved due to the clay loading, whereas the addition of nanoclay can improve the melting temperature and increase the crystallization rate. The large improvement of the storage modulus was observed in clay loaded composites. 2.0 wt% nanoclay/polypropylene nanocomposite showed less brittle fracture as compared to the ductile fracture of pure polypropylene. Ultraviolet radiation (UV) of the polymer chain was reduced by introducing the reinforcing agent such as organoclay into polypropylene. Overall, clay dispersed nanocomposites show a promising improvement of various properties.

The chemical modification or impregnation through preparing the wood polymer composites (WPCs) can effectively reduce the hygroscopicity as well as can improve the acoustic properties of wood. On the other hand, a small amount of nanoclay into the chemical mixture can further improve the different properties of the WPCs through the preparation of wood polymer nanocomposites (WPNCs). Kayu Malam wood species with styrene (St), vinyl acetate (VA), and montmorillonite (MMT) nanoclay were used for the preparation of WPNCs. The acoustic properties such as specific dynamic Young’s modulus (Ed/γ), internal friction (Q−1), and acoustic conversion efficiency (ACE) of wood were examined using free-free flexural vibration. It was observed that the chemically impregnated wood composite showed a higher value of Ed/γ than raw wood and the nanoclay-loaded wood nanocomposite showed the highest value. The reverse trend was observed in the case of Q−1. On the other hand, chemical impregnation has a minor effect on ACE of wood for musical instruments. The results suggested that the chemically impregnated Kayu Malam wood polymer nanocomposite (WPNC) is suitable for making soundboards of violin and guitar instruments to be played longer without losing tone quality.

The book chapter discussed the chemical composition, particle dispersion, cellular structure physical, mechanical, dynamic mechanical, electrical, and thermal properties, especially those involved in thermosetting and thermoplastics engineered polymer. It showed that the current progress, improvement, and development of silica and its nanocomposites were given more impact on the advanced properties. Throughout this book chapter, the fundamental understanding and knowledge on the use of silica and it challenges were observed morphologically, physically, mechanically, and chemically. Thus, this chapter helps to evaluate the value of understanding the development of silica and its nanocomposites for better future applications and open anew avenue for materials scientists seeking new functionality in the field of materials science.

The tensile properties of chemically treated jute fiber reinforced polyethylene/clay nanocomposites were investigated. Nanocomposites were prepared using hot press moulding technique by varying jute fiber loading (5, 10, 15 and 20 wt%) for both treated and untreated fibers. Raw jute fibers were chemically treated with benzene diazonium salt to increase their compatibility with the polyethylene matrix. Physical and mechanical properties were subsequently characterized. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) analysis was utilized to study physical properties. Tensile test was conducted for mechanical characterization. FTIR and SEM study showed interfacial interaction among jute fiber, polyethylene and nanoclay. It was observed that at optimum fiber content (15 wt%), treated composites exhibited improvements in tensile strength and modulus by approximately 20 % and 37 % respectively over the raw ones. On the other hand, this composite exhibited improvements in tensile strength and modulus by approximately 8 % and 15 % respectively over the composites without nanoclay. However, treated jute fiber reinforced composites showed better tensile properties compared with untreated ones and also nanoclay incorporated composites enhanced higher tensile properties compared without nanoclay ones.

Bamboo cellulose was prepared by chemical process involving dewaxing, delignification, and mercerization process. Four samples namely, green bamboo fiber (GBF), dewaxed bamboo fiber (DBF), delignified bamboo fiber (DLBF), and cellulose fiber (CF) had been analysed. FTIR and TGA analysis confirmed the removal of hemicellulose and lignin at the end stage of the process. FTIR results reveal that the D-cellulose OH group occurred at 1639 cm−1region. SEM micrograph showed that mercerization leads to fibrillation and breakage of the fiber into smaller pieces which promote the effective surface area available for contact. Barrer, Joiyner, and Halenda (BJH) method confirmed that the effective surface area of CF is two times larger compared to GBF. CF showed the highest activation energy compared to GBF. It indicates that CF was thermally stable.