Rapid industrial developments coupled with surging population growth have complicated issues dealing with water scarcity as the quest for clean and sanitized water intensifies globally. Existing fresh water supplies could be contaminated with organic, inorganic and biological matters that have potential harm to the society. Turbidity in general is a measure of water cloudiness induced by such colloidal and suspended matters and is also one of the major criteria in raw water monitoring to meet the stipulated water quality guidelines. Turbidity reduction is often accomplished using chemical coagulants such as alum. The use of alum is widely associated with potential development of health issues and generation of voluminous sludge. Natural coagulants that are available in abundance can certainly be considered in addressing the drawbacks associated with the use of chemical coagulants. Twenty one types of plant-based natural coagulants categorized as fruit waste and others are identified and presented collectively with their research summary in this review. The barriers and prospects of commercialization of natural coagulants in near future are also discussed.
Andrographolide (AG) is one of the most potent labdane diterpenoid-type free radical scavengers available from plant sources. The compound is the principal bioactive component in Andrographis paniculata leaf extracts, and is responsible for anti-inflammatory, anticancer, and immunomodulatory activity. The application of AG in therapeutics, however, is severely constrained, due to its low aqueous solubility, short biological half-life, and poor cellular permeability. Engineered nanoparticles in biodegradable polymer systems were therefore conceived as one solution to aid in further drug-like applications of AG. In this study, a cationic modified poly(lactic-co-glycolic) acid nanosystem was applied for evaluation against experimental mouse hepatotoxic conditions. Biopolymeric nanoparticles of hydrodynamic size of 229.7 ± 17.17 nm and ζ-potential +34.4 ± 1.87 mV facilitated marked restoration in liver functions and oxidative stress markers. Superior dissolution for bioactive AG, hepatic residence, and favorable cytokine regulation in the liver tissues are some of the factors responsible for the newer nanosystem-assisted rapid recovery.
The magnetohydrodynamic (MHD) stagnation point flow of a nanofluid over a permeable stretching/shrinking sheet is studied. Numerical results are obtained using boundary value problem solver bvp4c in MATLAB for several values of parameters. The numerical results show that dual solutions exist for the shrinking case, while for the stretching case, the solution is unique. A stability analysis is performed to determine the stability of the dual solutions. For the stable solution, the skin friction is higher in the presence of magnetic field and increases when the suction effect is increased. It is also found that increasing the Brownian motion parameter and the thermophoresis parameter reduces the heat transfer rate at the surface.
Vindogentianine, a new indole alkaloid together with six known alkaloids, vindoline, vindolidine, vindolicine, vindolinine, perivine and serpentine were isolated from leaf extract (DA) of Catharanthus roseus (L.) G. Don. Their structures were elucidated by spectroscopic methods; NMR, MS, UV and IR. Vindogentianine is a dimer containing a vindoline moiety coupled to a gentianine moiety. After 24h incubation, vindogentianine exhibited no cytotoxic effect in C2C12 mouse myoblast and β-TC6 mouse pancreatic cells (IC50>50μg/mL). Real-time cell proliferation monitoring also indicated vindogentianine had little or no effect on C2C12 mouse myoblast cell growth at the highest dose tested (200μg/mL), without inducing cell death. Vindogentianine exhibited potential hypoglycemic activity in β-TC6 and C2C12 cells by inducing higher glucose uptake and significant in vitro PTP-1B inhibition. However, in vitro α-amylase and α-glucosidase inhibition assay showed low inhibition under treatment of vindogentianine. This suggests that hypoglycemic activity of vindogentianine may be due to the enhancement of glucose uptake and PTP-1B inhibition, implying its therapeutic potential against type 2 diabetes.
The search for renewable energy sources has become challenging in the current era, as conventional fuel sources are of finite origins. Recent research interest has focused on various biophotovoltaic (BPV) platforms utilizing algae, which are then used to harvest solar energy and generate electrical power. The majority of BPV platforms incorporate indium tin oxide (ITO) anodes for the purpose of charge transfer due to its inherent optical and electrical properties. However, other materials such as reduced graphene oxide (RGO) could provide higher efficiency due to their intrinsic electrical properties and biological compatibility. In this work, the performance of algae biofilms grown on RGO and ITO anodes were measured and discussed. Results indicate improved peak power of 0.1481 mWm(-2) using the RGO electrode and an increase in efficiency of 119%, illustrating the potential of RGO as an anode material for applications in biofilm derived devices and systems.
In an effort to develop new antibacterial drugs, some novel bisindolylmethane derivatives containing Schiff base moieties were prepared and screened for their antibacterial activity. The synthesis of the bisindolylmethane Schiff base derivatives 3-26 was carried out in three steps. First, the nitro group of 3,3'-((4-nitrophenyl)-methylene)bis(1H-indole) (1) was reduced to give the amino substituted bisindolylmethane 2 without affecting the unsaturation of the bisindolylmethane moiety using nickel boride in situ generated. Reduction of compound 1 using various catalysts showed that combination of sodium borohydride and nickel acetate provides the highest yield for compound 2. Bisindolylmethane Schiff base derivatives were synthesized by coupling various benzaldehydes with amino substituted bisindolylmethane 2. All synthesized compounds were characterized by various spectroscopic methods. The bisindolylmethane Schiff base derivatives were evaluated against selected Gram-positive and Gram-negative bacterial strains. Derivatives having halogen and nitro substituent display weak to moderate antibacterial activity against Salmonella typhi, S. paratyphi A and S. paratyphi B.
An innovative approach using soybean residues for the production of bioflocculants through solid-state fermentation was carried out in 4.5 L near-to-adiabatic bioreactors at pilot-scale level. An added inoculum of the strain Bacillus subtilis UPMB13 was tested in comparison with control reactors without any inoculation after the thermophilic phase of the fermentation. The flocculating performances of the extracted bioflocculants were tested on kaolin suspensions, and crude bioflocculants were obtained from 20 g of fermented substrate through ethanol precipitation. The production of bioflocculants was observed to be higher during the death phase of microbial growth. The bioflocculants were observed to be granular in nature and consisted of hydroxyl, carboxyl and methoxyl groups that aid in their flocculating performance. The results show the vast potential of the idea of using wastes to produce bioactive materials that can replace the current dependence on chemicals, for future prospect in water treatment applications.
Atherosclerosis is the process of hardening and narrowing the arteries. Atherosclerosis is generally associated with cardiovascular diseases such as strokes, heart attacks, and peripheral vascular diseases. Since the usage of the synthetic drug, statins, leads to various side effects, the plants flavonoids with antiartherosclerotic activity gained much attention and were proven to reduce the risk of atherosclerosis in vitro and in vivo based on different animal models. The flavonoids compounds also exhibit lipid lowering effects and anti-inflammatory and antiatherogenic properties. The future development of flavonoids-based drugs is believed to provide significant effects on atherosclerosis and its related diseases. This paper discusses the antiatherosclerotic effects of selected plant flavonoids such as quercetin, kaempferol, myricetin, rutin, naringenin, catechin, fisetin, and gossypetin.
In the study, the relationship between the quality and intensity of LED illumination with FAMEs produced were investigated. Nannochloropsis sp. was cultivated for 14 days under different intensities of 100, 150 and 200 μmol photons m(-2) s(-1) of red, blue and mixed red blue LED. The findings revealed that suitable combination of LED wavelengths and intensity; (red LED: 150, blue: 100 and mixed red blue: 200 μmol photons m(-2) s(-1)) produced maximum biomass growth and lipid content. It was observed that the quality and intensity of LED significantly influenced the composition of FAMEs. FAMEs produced under blue LED has high degree of unsaturation (DU) and low cetane number while those under red LED has low DU but higher CN. The combination of red blue LED has produced FAMEs with high ignition and lubricating property and also good oxidation stability indicated by the DU and CN values which lies midway between the red and blue.
In this study, HA is superplastically embedded into Titanium substrate and the sample is subsequently deformed superplastically until 70% deformation degree. The former process is termed as superplastic embedment (SPE) while the later as superplastic deformation (SPD). After the SPE, HA is successfully embedded into the substrate, forming a layer with a thickness of about 249 nm. After the SPD the embedded HA layer thickness decreases to 111 nm. The SPD sample is then immersed in simulated body fluid (SBF) to evaluate its biological properties. A newly grown apatite is formed as a result of the immersion and the HA layer thickness increases with immersion time. The cohesion and adhesion strength within the HA coating and coating-substrate interface of the SPD samples before and after immersion in the SBF is evaluated through the nanoscratch test technique. The results indicate that the HA layer after SPD is still strong even though after being exposed in SBF environment for quite some time. The study suggests that the superplastically embedded HA nanolayer is still intact mechanically and functioning appropriately as biological activity base even after the SPD process.
Silver and copper nanoparticles were produced by chemical reduction of their respective nitrates by ascorbic acid in the presence of chitosan using microwave heating. Particle size was shown to increase by increasing the concentration of nitrate and reducing the chitosan concentration. Surface zeta potentials were positive for all nanoparticles produced and these varied from 27.8 to 33.8 mV. Antibacterial activities of Ag, Cu, mixtures of Ag and Cu, and Ag/Cu bimetallic nanoparticles were tested using Bacillus subtilis and Escherichia coli. Of the two, B. subtilis proved more susceptible under all conditions investigated. Silver nanoparticles displayed higher activity than copper nanoparticles and mixtures of nanoparticles of the same mean particle size. However when compared on an equal concentration basis Cu nanoparticles proved more lethal to the bacteria due to a higher surface area. The highest antibacterial activity was obtained with bimetallic Ag/Cu nanoparticles with minimum inhibitory concentrations (MIC) of 0.054 and 0.076 mg/L against B. subtilis and E. coli, respectively.
Matched MeSH terms: Anti-Infective Agents/chemistry*; Ascorbic Acid/chemistry; Copper/chemistry*; Silver/chemistry*; Chitosan/chemistry*; Metal Nanoparticles/chemistry*; Green Chemistry Technology
A series of novel carbonyl compounds was synthesized by a simple, eco-friendly and efficient method. These compounds were screened for anti-oxidant activity, in vitro cytotoxicity and for inhibitory activity for acetylcholinesterase and butyrylcholinesterase. The effect of these compounds against amyloid β-induced cytotoxicity was also investigated. Among them, compound 14 exhibited strong free radical scavenging activity (18.39 μM) while six compounds (1, 3, 4, 13, 14, and 19) were found to be the most protective against Aβ-induced neuronal cell death in PC12 cells. Compounds 4 and 14, containing N-methyl-4-piperidone linker, showed high acetylcholinesterase inhibitory activity as compared to reference drug donepezil. Molecular docking and QSAR (Quantitative Structure-Activity Relationship) studies were also carried out to determine the structural features that are responsible for the acetylcholinesterase and butyrylcholinesterase inhibitory activity.
The popularity of low cost, lightweight, and environmentally affable masonry unit in building industry carries the need to investigate more flexible and adaptable brick component as well as to retain the requirements confirmed in building standards. In this study, potential use of local materials used as lightweight building materials in solving the economic problems of housing has been investigated. Experimental studies on peat added bricks have been carried out. It demonstrates the physicomechanical properties of bricks and investigates the influence of peat, sand, and cement solid bricks to the role of various types of constructional applications. The achieved compressive strength, spitting strength, flexural strength, unit weight, and ultrasonic pulse velocity are significantly reduced and the water absorption is increased with percentage wise replacement of peat as aggregate in the samples. The maximum 20% of (% mass) peat content meets the requirements of relevant well-known international standards. The experimental values illustrate that, the 44% volumetric replacement with peat did not exhibit any sudden brittle fracture even beyond the ultimate loads and a comparatively smooth surface is found. The application of peat as efficient brick substance shows a potential to be used for wall and a viable solution in the economic buildings design.
Circularly polarized (CP) dual frequency cross-shaped slotted patch antenna on 1.575 mm thick glass microfiber reinforced polytetrafluoroethylene (PTFE) composite material substrate is designed and fabricated for satellite applications. Asymmetric cross-shaped slots are embedded in the middle of the square patch for CP radiation and four hexagonal slots are etched on the four sides of the square patch for desired dual frequency. Different substrate materials have been analysed to achieve the desired operating band. The experimental results show that the impedance bandwidth is approximately 30 MHz (2.16 GHz to 2.19 GHz) for lower band and 40 MHz (3.29 GHz to 3.33 GHz) for higher band with an average peak gain of 6.59 dBiC and 5.52 dBiC, respectively. Several optimizations are performed to obtain the values of the antenna physical parameters. Moreover, the proposed antenna possesses compactness, light weight, simplicity, low cost, and circularly polarized. It is an attractive candidate for dual band satellite antennas where lower band can be used for uplink and upper band can be used for downlink.
Crystals of 1,6-hexanedioic acid (I) undergo a temperature-dependent reversible phase transition from monoclinic P21/c at a temperature higher than the critical temperature (Tc) 130 K to another monoclinic P21/c at temperature lower than Tc. The phase transition is of first order, involving a discontinuity and a tripling of the b-axis at Tc whereas the other unit cell parameters vary continuously. The transition is described by the phenomenological Landau theory. The crystal structure analyses for data collected at 297(2) K and 120.0(1) K show that there is half of a molecule of (I) in the asymmetric unit at 297(2) K whereas there are one and a half molecules of (I) in the asymmetric unit at 120.0(1) K. At both temperatures, 297(2) and 120.0(1) K, intermolecular O-H···O hydrogen bonds link the molecules of I into infinite 1D chains along [101] direction. However there are significantly more O-H···O hydrogen bonds presented in the 120.0(1) K polymorph, thereby indicating this phase transition is negotiated via hydrogen bonds. The relationship of the conformational changes and hydrogen bonding for these two polymorphs are explained in detail.
Runoff potentiality of a watershed was assessed based on identifying curve number (CN), soil conservation service (SCS), and functional data analysis (FDA) techniques. Daily discrete rainfall data were collected from weather stations in the study area and analyzed through lowess method for smoothing curve. As runoff data represents a periodic pattern in each watershed, Fourier series was introduced to fit the smooth curve of eight watersheds. Seven terms of Fourier series were introduced for the watersheds 5 and 8, while 8 terms of Fourier series were used for the rest of the watersheds for the best fit of data. Bootstrapping smooth curve analysis reveals that watersheds 1, 2, 3, 6, 7, and 8 are with monthly mean runoffs of 29, 24, 22, 23, 26, and 27 mm, respectively, and these watersheds would likely contribute to surface runoff in the study area. The purpose of this study was to transform runoff data into a smooth curve for representing the surface runoff pattern and mean runoff of each watershed through statistical method. This study provides information of runoff potentiality of each watershed and also provides input data for hydrological modeling.
Biosensor chips for immune-based assay systems have been investigated for their application in early diagnostics. The development of such systems strongly depends on the effective protein immobilization on polymer substrates. In order to achieve this complex heterogeneous interaction the polymer surface must be functionalized with chemical groups that are reactive towards proteins in a way that surface functional groups (such as carboxyl, -COOH; amine, -NH2; and hydroxyl, -OH) chemically or physically anchor the proteins to the polymer platform. Since the proteins are very sensitive towards their environment and can easily lose their activity when brought in close proximity to the solid surface, effective surface functionalization and high level of control over surface chemistry present the most important steps in the fabrication of biosensors. This paper reviews recent developments in surface functionalization and preparation of polymethacrylates for protein immobilization. Due to their versatility and cost effectiveness, this particular group of plastic polymers is widely used both in research and in industry.
The structure of 2-acetyl-5-chlorothiophene (ACT) has been characterized by FT-IR, Raman and single-crystal X-ray diffraction techniques. The isomers, optimized geometric parameters, normal mode frequencies and corresponding vibrational assignments of ACT (C6H5ClOS) have been examined by the density functional theory, with the Becke-3-Lee-Yang-Parr functional and the 6-311+G(3df,p) basis set. Reliable vibrational assignments have been investigated by the potential energy distribution analysis. ACT crystallizes in monoclinic space group C2/c with the O,S-cis isomer. There is a good agreement between the theoretically predicted structural parameters and vibrational frequencies and those obtained experimentally.
Nystatin is a tetraene diene polyene antibiotic showing a broad spectrum of antifungal activity. In the present study, we prepared a nystatin nanocomposite (Nyst-CS-MNP) by loading nystatin (Nyst) on chitosan (CS) coated magnetic nanoparticles (MNPs). The magnetic nanocomposites were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetry analysis (TGA), vibrating sample magnetometer (VSM), and scanning electron microscopy (SEM). The XRD results showed that the MNPs and nanocomposite are pure magnetite. The FTIR analysis confirmed the binding of CS on the surface of the MNPs and also the loading of Nyst in the nanocomposite. The Nyst drug loading was estimated using UV-Vis instrumentation and showing a 14.9% loading in the nanocomposite. The TEM size image of the MNPs, CS-MNP, and Nyst-CS-MNP was 13, 11, and 8 nm, respectively. The release profile of the Nyst drug from the nanocomposite followed a pseudo-second-order kinetic model. The antimicrobial activity of the as-synthesized Nyst and Nyst-CS-MNP nanocomposite was evaluated using an agar diffusion method and showed enhanced antifungal activity against Candida albicans. In this manner, this study introduces a novel nanocomposite that can decrease fungus activity on-demand for numerous medical applications.