Polymer‐based nanodiscs are valuable tools in biomedical research that can offer a detergent‐free solubilization of membrane proteins maintaining their native lipid environment. Herein, we introduce ...a novel ca. 1.6 kDa SMA‐based polymer with styrene:maleic acid moieties that can form nanodiscs containing a planar lipid bilayer which are useful to reconstitute membrane proteins for structural and functional studies. The physicochemical properties and the mechanism of formation of polymer‐based nanodiscs are characterized by light scattering, NMR, FT‐IR, and TEM. A remarkable feature is that nanodiscs of different sizes, from nanometer to sub‐micrometer diameter, can be produced by varying the lipid‐to‐polymer ratio. The small‐size nanodiscs (up to ca. 30 nm diameter) can be used for solution NMR spectroscopy studies whereas the magnetic‐alignment of macro‐nanodiscs (diameter of > ca. 40 nm) can be exploited for solid‐state NMR studies on membrane proteins.
Discrete bilayers: Lipid bilayer nanodiscs of different size are formed by using modified styrene maleic acid co‐polymer. The small‐size nanodiscs (up to ca. 30 nm diameter) can be used for solution NMR spectroscopy studies, whereas the magnetic alignment of large‐size nanodiscs (or macro‐nanodiscs with a diameter of >40 nm) can be exploited for solid‐state NMR studies on membrane proteins.
Plasticized poly(vinyl chloride) (PVC) has been extensively utilized globally, with various applications in construction, piping, wiring and cable, installation, flooring, nonfood packing, windows, ...doors, and more. Phthalates have been the most commonly employed plasticizers for PVC, but some of these plasticizers demonstrate many toxic effects on the environment and human beings, which consequently limits the use of phthalate plasticizers. Growing awareness of the effects of plasticizers on the environment and the depletion of petroleum-based resources has made the development of an alternative biobased plasticizer for PVC formulation necessary. Recently, there has been an increased consciousness of the use of natural resource-based plasticizers instead of phthalates in PVC production, because they are eco-friendly in nature. This review paper covers the utilization of traditional and biobased plasticizers for PVC plasticization, and their effect on environmental, mechanical, and thermal properties has been reported.
The optical spectrum of liquid water is analyzed by subsystem time-dependent density functional theory. We provide simple explanations for several important (and so far elusive) features. Due to the ...disordered environment surrounding each water molecule, the joint density of states of the liquid is much broader than that of the vapor, thus explaining the red-shifted Urbach tail of the liquid compared to the gas phase. Confinement effects provided by the first solvation shell are responsible for the blue shift of the first absorption peak compared to the vapor. In addition, we also characterize many-body excitonic effects. These dramatically affect the spectral weights at low frequencies, contributing to the refractive index by a small but significant amount.
The present study deals with the bioremediation of potentially hazardous pulp and paper mill effluent by a laccase producing Paenibacillus sp. strain LD-1 (JX499920) isolated from contaminated soil ...sample by lignin enrichment method. The bacterium effectively reduced pollution parameters (colour 68%, lignin 54%, phenol 86%, BOD 83% and COD 78%) after 144h of treatment at 34±1°C and 120rpm. GC–MS analysis of control and treated samples showed that concentration of most of the low molecular weight phenolic compounds like 2-methoxyphenol, 2,6-dimethoxy phenol, 2-methoxy-4-ethyl-phenol, 3-allyl-6-methoxyphenol, ethanone 1-(-4-hydroxy-3,5-dimethoxyphenyl), benzoic acid, 2-methoxy-4-(1-propenyl) phenol and 4-methoxycinnamic acid present in control untreated effluent were reduced after bacterial treatment. The toxicity assessments were carried out with treated and untreated effluent by studying the growth and germination of seeds of mung bean (Vigna radiata L.). The mung bean bioassay confirmed the detoxification of effluent after bacterial treatment.
Bioaerosols significantly affect atmospheric processes while they undergo long-range vertical and horizontal transport and influence atmospheric chemistry and physics and climate change.Accumulating ...evidence suggests that exposure to bioaerosols may cause adverse health effects,including severe disease.Studies of bioaerosols have primarily focused on their chemical composition and largely neglected their biological composition and the negative effects of biological composition on ecosystems and human health.Here,current molecular methods for the identification,quantification,and distribution of bioaerosol agents are reviewed.Modern developments in environmental microbiology technology would be favorable in elucidation of microbial temporal and spatial distribution in the atmosphere at high resolution.In addition,these provide additional supports for growing evidence that microbial diversity or composition in the bioaerosol is an indispensable environmental aspect linking with public health.
Spherical nanoparticles of zinc oxide (ZnO NPs) were synthesized by an eco-friendly green combustion method using citrate containing Artocarpus gomezianus fruit extract as a fuel. The morphology, ...compositions and structure of the product were characterized by Powder X-ray Diffraction (PXRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier Transform Infra-red (FTIR), UV–Visible (UV–Vis) and Raman Spectroscopy. Highly uniform spherical zinc oxide NPs were subjected to cytotoxicity, antifungal and antibacterial activities. PXRD patterns show that the product formed belongs to a hexagonal wurtzite system. SEM micrographs reveal that the particles are agglomerated. The TEM images demonstrate that the particles are highly uniform spherical in shape and loosely agglomerated. Scherrer's method and WH plots were used to calculate the average crystallite sizes, yielding 39, 35, 31 and 40, 37, 32 nm for ZnO NPs prepared with 5, 10 and 15 mL of 10% Artocarpusgomezianus fruit extract, respectively. These results were confirmed by the TEM observations. Breast cancer cell lines (MCF-7) were subjected to in vitro anticancer activity. MTT assay revealed a good anticancer activity of ZnO NPs against MCF-7. Zone of the inhibition method shows that the spherical ZnO NPs also exhibit significant antibacterial activity against staphylococcus aureus and antifungal activity against Aspergillus niger. The synthesized ZnO NPs can find plausible biological applications.
•Wurtzite hexagonal ZnO NPs are synthesized by eco-friendly green combustion method using citrate containing Artocarpus gomezianus fruit extract as a fuel.•In vitro anticancer activity was carried out against breast cancer cell lines (MCF-7).•Zone of inhibition method shows the spherical ZnO NPs exhibit significant antibacterial activity against Staphylococcus aureus and antifungal activity against Aspergillus niger.
Polymer lipid nanodiscs are an invaluable system for structural and functional studies of membrane proteins in their near‐native environment. Despite the recent advances in the development and usage ...of polymer lipid nanodisc systems, lack of control over size and poor tolerance to pH and divalent metal ions are major limitations for further applications. A facile modification of a low‐molecular‐weight styrene maleic acid copolymer is demonstrated to form monodispersed lipid bilayer nanodiscs that show ultra‐stability towards divalent metal ion concentration over a pH range of 2.5 to 10. The macro‐nanodiscs (>20 nm diameter) show magnetic alignment properties that can be exploited for high‐resolution structural studies of membrane proteins and amyloid proteins using solid‐state NMR techniques. The new polymer, SMA‐QA, nanodisc is a robust membrane mimetic tool that offers significant advantages over currently reported nanodisc systems.
All under control: A poor tolerance to pH and divalent metal ions and a lack of control over size are major limitations of polymer nanodiscs. A modified styrene maleimide based polymer is demonstrated to form monodispersed nanodiscs with ultrahigh stability towards divalent metal ions over a pH range of 2.5 to 10.
AbstractPond ash (PA) and cement kiln dust (CKD) are major dust products from thermal power stations and cement manufacturing industries and pose disposal difficulties. This research work focuses on ...the geotechnical properties of pond ash mixed with cement dust and polypropylene (PP) fiber. Various experimental tests, including standard Proctor test, California bearing ratio (CBR) test, direct shear test, and triaxial shear tests, were performed. Pond ash was mixed with 10, 15, 20, 25, and 30% of CKD and 0.5, 1, and 1.5% polypropylene fiber. Standard Proctor tests were carried out on various proposed proportions in order to obtain the effective mix. Original pond ash maximum dry density and optimum moisture contents are 1.45 g/cm3 and 23%, respectively. The mix of 75% PA, 25% CKD, and 1% PP fiber produced the maximum dry density. The CBR values increased gradually up to 80% for up to 25% CKD and 1% PP fiber. The shear strength parameters were determined using direct shear testing. The shear strength parameters of cohesion (c) and angle of internal friction (ϕ) obtained for the mix of 75% PA, 25% CKD, and 1% PP fiber were 5 kN/m2 and 39.45°. The same composition was tested in triaxial shear tests under consolidated drained conditions, and shear strength parameters varied slightly. The mix of pond ash, cement kiln dust, and PP fiber can be used for highway embankment construction to strengthen its layers, low land area reclamation, as a structural fill in reinforced earth walls, and backfill material for conventional retaining walls.
Obstructive sleep apnea (OSA) is a common respiratory disorder marked by interruption of the respiratory tract and difficulty in breathing. The risk of serious health damage can be reduced if OSA is ...diagnosed and treated at an early stage. OSA is primarily diagnosed using polysomnography (PSG) monitoring performed for overnight sleep; furthermore, capturing PSG signals during the night is expensive, time-consuming, complex and highly inconvenient to patients. Hence, we are proposing to detect OSA automatically using respiratory and oximetry signals. The aim of this study is to develop a simple and computationally efficient wavelet-based automated system based on these signals to detect OSA in elderly subjects.
In this study, we proposed an accurate, reliable, and less complex OSA automated detection system by using pulse oximetry (SpO2) and respiratory signals including thoracic (ThorRes) movement, abdominal (AbdoRes) movement, and airflow (AF). These signals are collected from the Sleep Heart Health Study (SHHS) database from the National Sleep Research Resource (NSRR), which is one of the largest repositories of publicly available sleep databases. The database comprises of two groups SHHS-1 and SHHS-2, which involves 5,793 and 2,651 subjects, respectively with an average age of ≥60 years. The 30-s epochs of the signals are decomposed into sub-bands using frequency optimized orthogonal wavelet filter bank. Tsallis entropies are extracted from the sub-band coefficients of wavelet filter bank. A total 4,415,229 epochs of respiratory and oximetry signals are used to develop the model. The proposed model is developed using GentleBoost and Random under-sampling Boosting (RUSBoosted Tree) algorithms with 10-fold cross-validation technique.
Our developed model has obtained the highest classification accuracy of 89.39% and 84.64% for the imbalanced and balanced datasets, respectively using 10-fold cross-validation technique. Using the 20% hold-out validation, the model yielded an accuracy of 88.26% and 84.31% for the imbalanced and balanced datasets, respectively. Hence, the respiratory and SpO2 signals-based model can be used for automated OSA detection. The results obtained from the proposed model are better than the state-of-the-art models and can be used in-home for screening the OSA.
•An automated system to detect sleep apnea using respiratory and oximetry signals.•More than 8000 subjects employed from a public database.•A new frequency optimized orthogonal wavelet filter bank is employed.•Only one set of features is used Simple method and high classification performance.
There is a growing interest in the use of lipid bilayer nanodiscs for various biochemical and biomedical applications. Among the different types of nanodiscs, the unique features of synthetic ...polymer-based nanodiscs have attracted additional interest. A styrene–maleic acid (SMA) copolymer demonstrated to form lipid nanodiscs has been used for structural biology related studies on membrane proteins. However, the application of SMA polymer based lipid nanodiscs is limited because of the strong absorption of the aromatic group interfering with various experimental measurements. Thus, there is considerable interest in the development of other molecular frameworks for the formation of polymer-based lipid nanodiscs. In this study, we report the first synthesis and characterization of a library of polymethacrylate random copolymers as alternatives to SMA polymer. In addition, we experimentally demonstrate the ability of these polymers to form lipid bilayer nanodiscs through the fragmentation of lipid vesicles by means of light scattering, electron microscopy, differential scanning calorimetry, and solution and solid-state NMR experiments. We further demonstrate a unique application of the newly developed polymer for kinetics and structural characterization of the aggregation of human islet amyloid polypeptide (also known as amylin) within the lipid bilayer of the polymer nanodiscs using thioflavin-T-based fluorescence and circular dichroism experiments. Our results demonstrate that the reported new styrene-free polymers can be used in high-throughput biophysical experiments. Therefore, we expect that the new polymer nanodiscs will be valuable in the structural studies of amyloid proteins and membrane proteins by various biophysical techniques.
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