Parkinson's disease (PD) is not only characterized by its prominent motor symptoms but also associated with disturbances in cognitive and emotional functioning. The objective of the present study was to investigate the influence of emotion processing on inter-hemispheric electroencephalography (EEG) coherence in PD. Multimodal emotional stimuli (happiness, sadness, fear, anger, surprise, and disgust) were presented to 20 PD patients and 30 age-, education level-, and gender-matched healthy controls (HC) while EEG was recorded. Inter-hemispheric coherence was computed from seven homologous EEG electrode pairs (AF3-AF4, F7-F8, F3-F4, FC5-FC6, T7-T8, P7-P8, and O1-O2) for delta, theta, alpha, beta, and gamma frequency bands. In addition, subjective ratings were obtained for a representative of emotional stimuli. Interhemispherically, PD patients showed significantly lower coherence in theta, alpha, beta, and gamma frequency bands than HC during emotion processing. No significant changes were found in the delta frequency band coherence. We also found that PD patients were more impaired in recognizing negative emotions (sadness, fear, anger, and disgust) than relatively positive emotions (happiness and surprise). Behaviorally, PD patients did not show impairment in emotion recognition as measured by subjective ratings. These findings suggest that PD patients may have an impairment of inter-hemispheric functional connectivity (i.e., a decline in cortical connectivity) during emotion processing. This study may increase the awareness of EEG emotional response studies in clinical practice to uncover potential neurophysiologic abnormalities.
In this research, silver nanoparticles (AgNPs) were synthesized in chitosan (Cts), Cts/gelatin and gelatin suspensions using a chemical reducing agent. Cts and gelatin were used as natural stabilizers and solid support, whereas AgNO(3) was used as the silver precursor. Sodium borohydride (NaBH(4)) was used as the reducing agent. The properties of AgNPs in Cts, Cts/gelatin and gelatin bionanocomposites (BNCs) were studied in terms of their surface plasmon resonance, crystalline structure, average diameter size, particle distributions, surface topography and functional groups. All the samples were characterized by UV-visible spectroscopy, powder X-ray diffraction, transmission electron microscopy, atomic force microscopy and Fourier transform infrared spectroscopy.
Homogenous strain analysis (HSA) was developed to evaluate regional cardiac function using tagged cine magnetic resonance images of heart. Current cardiac applications of HSA are however limited in accurately detecting tag intersections within the myocardial wall, producing consistent triangulation of tag cells throughout the image series and achieving optimal spatial resolution due to the large size of the triangles. To address these issues, this article introduces a harmonic phase (HARP) interference method. In principle, as in the standard HARP analysis, the method uses harmonic phases associated with the two of the four fundamental peaks in the spectrum of a tagged image. However, the phase associated with each peak is wrapped when estimated digitally. This article shows that special combination of wrapped phases results in an image with unique intensity pattern that can be exploited to automatically detect tag intersections and to produce reliable triangulation with regularly organized partitioning of the mesh for HSA. In addition, the method offers new opportunities and freedom for evaluating myocardial function when the power and angle of the complex filtered spectra are mathematically modified prior to computing the phase. For example, the triangular elements can be shifted spatially by changing the angle and/or their sizes can be reduced by changing the power. Interference patterns obtained under a variety of power and angle conditions were presented and specific features observed in the results were explained. Together, the advanced processing capabilities increase the power of HSA by making the analysis less prone to errors from human interactions. It also allows strain measurements at higher spatial resolution and multi-scale, thereby improving the display methods for better interpretation of the analysis results.
Cardiovascular disease (CVD) is the leading cause of death worldwide, and due to the lack of early detection techniques, the incidence of CVD is increasing day by day. In order to address this limitation, a knowledge based system with embedded intelligent heart sound analyser (KBHSA) has been developed to diagnose cardiovascular disorders at early stages. The system analyses digitized heart sounds that are recorded from an electronic stethoscope using advanced digital signal processing and artificial intelligence techniques. KBHSA takes into account data including the patient's personal and past medical history, clinical examination, auscultation findings, chest x-ray and echocardiogram, and provides a list of diseases that it has diagnosed. The system can assist the general physician in making more accurate and reliable diagnosis under emergency conditions where expert cardiologists and advanced equipment are not readily available. To test the validity of the system, abnormal heart sound samples and medical data from 40 patients were recorded and analysed. The diagnoses made by the system were counter checked by four senior cardiologists in Malaysia. The results show that the findings of KBHSA coincide with those of cardiologists.
Doxorubicin-loaded micelles were prepared from a copolymer comprising cholic acid (CA) and polyethyleneimine (PEI) for the delivery of antitumor drugs. The CA-PEI copolymer was synthesized via pairing mediated by N,N'-dicyclohexylcarbodiimide and N-hydroxysuccinimide using dichloromethane as a solvent. Fourier transform infrared and nuclear magnetic resonance analyses were performed to verify the formation of an amide linkage between CA and PEI and doxorubicin localization into the copolymer. Dynamic light scattering and transmission electron microscopy studies revealed that the copolymer could self-assemble into micelles with a spherical morphology and an average diameter of <200 nm. The CA-PEI copolymer was also characterized by X-ray diffraction and differential scanning calorimetry. Doxorubicin-loaded micelles were prepared by dialysis method. A drug release study showed reduced drug release with escalating drug content. In a cytotoxicity assay using human colorectal adenocarcinoma (DLD-1) cells, the doxorubicin-loaded CA-PEI micelles exhibited better antitumor activity than that shown by doxorubicin. This is the first study on CA-PEI micelles as doxorubicin carriers, and this study demonstrated that they are promising candidates as carriers for sustained targeted antitumor drug delivery system.
In this paper, 3-D discrete Hartley transform is applied for the compression of two medical modalities, namely, magnetic resonance images and X-ray angiograms and the performance results are compared with those of 3-D discrete cosine and Fourier transforms using the parameters such as PSNR and bit rate. It is shown that the 3-D discrete Hartley transform is better than the other two transforms for magnetic resonance brain images whereas for the X-ray angiograms, the 3-D discrete cosine transform is found to be superior.
In this study, an amphiphilic chitosan derivative namely N,N-dimethylhexadecyl carboxymethyl chitosan (DCMC) was synthesised and applied for the first time as a carrier agent for rotenone. The physical and chemical properties of DCMC were characterised by using Fourier Transform Infrared Spectrometer (FTIR), Proton Nuclear Magnetic Resonance Spectrometer ((1)H NMR), CHN-O Elemental Analyser, Thermogravimetric Analyser (TGA) and Differential Scanning Calorimeter (DSC). DCMC was soluble in acidic (except pH 4), neutral and basic media with percent of transmittance (%T) values ranged from 67.2 to 99.4%. The critical micelle concentration (CMC) was determined as 0.095mg/mL. Transmission Electron Microscopy (TEM) analysis confirmed that DCMC has formed self-aggregates and exhibited spherical shape with the size of 65.5-137.0nm. The encapsulation efficiency (EE) and loading capacity (LC) of DCMC micelles with different weight ratios (DCMC:rotenone; 5:1, 50:1 and 100:1) were determined by using High Performance Liquid Chromatography (HPLC). The weight ratio of 100:1 gave the best EE with the value of more than 95.0%. DCMC micelles performed an excellent ability to control the release of rotenone, of which 99.0% of rotenone was released within 48h. Overall, DCMC has several key features to be an effective carrier agent for pesticide formulations.
In this work, zinc chromite (ZnCr2O4) nanostructures have been synthesized through co-precipitation method. The effect of various parameters such as alkaline agent, pH value, and capping agent type was investigated on purity, particle size and morphology of samples. It was found that particle size and morphology of the products could be greatly influenced via these parameters. The synthesized products were characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), fourier transform infrared (FT-IR) spectra, X-ray energy dispersive spectroscopy (EDS), photoluminescence (PL) spectroscopy, diffuse reflectance spectroscopy (DRS) and vibrating sample magnetometry (VSM). The superhydrophilicity of the calcined oxides was investigated by wetting experiments and a sessile drop technique which carried out at room temperature in air to determine the surface and interfacial interactions. Furthermore, the photocatalytic activity of ZnCr2O4 nanoparticles was confirmed by degradation of anionic dyes such as Eosin-Y and phenol red under UV light irradiation. The obtained ZnCr2O4 nanoparticles exhibit a paramagnetic behavior although bulk ZnCr2O4 is antiferromagnetic, this change in magnetic property can be ascribed to finite size effects.
Recently, research has validated the use of Polar® heart rate monitors as a tool to index heart rate variability (HRV). In the current investigation, we sought to evaluate the test-retest reliability of both time and frequency domain measures of HRV using the Polar® RS800CX™ . Continuous HRV data were collected as 60 nominally healthy adults underwent a resting and orthostatic stress test. We evaluated reproducibility by means of the interclass correlation coefficient for absolute agreement and consistency, and the standard error of measurement. We found moderate reliable 2-week test-retest reliability of HRV using the Polar® RS800CX™ , results that are in line with previous studies that have validated the stability of HRV using other methods of measurement (e.g. electrocardiogram). Additionally, when examining different methods of spectral density estimation, we found that using the auto-regressive transformation method provides the most stable indices of HRV. Taken together, our results suggest that the Polar® RS800CX™ is not only a valid method to record HRV, but also a reliable one, particularly when using the auto-regressive transformation method.
Wavelet-based image coding algorithms (lossy and lossless) use a fixed perfect reconstruction filter-bank built into the algorithm for coding and decoding of images. However, no systematic study has been performed to evaluate the coding performance of wavelet filters on medical images. We evaluated the best types of filters suitable for medical images in providing low bit rate and low computational complexity. In this study a variety of wavelet filters are used to compress and decompress computed tomography (CT) brain and abdomen images. We applied two-dimensional wavelet decomposition, quantization and reconstruction using several families of filter banks to a set of CT images. Discreet Wavelet Transform (DWT), which provides efficient framework of multi-resolution frequency was used. Compression was accomplished by applying threshold values to the wavelet coefficients. The statistical indices such as mean square error (MSE), maximum absolute error (MAE) and peak signal-to-noise ratio (PSNR) were used to quantify the effect of wavelet compression of selected images. The code was written using the wavelet and image processing toolbox of the MATLAB (version 6.1). This results show that no specific wavelet filter performs uniformly better than others except for the case of Daubechies and bi-orthogonal filters which are the best among all. MAE values achieved by these filters were 5 x 10(-14) to 12 x 10(-14) for both CT brain and abdomen images at different decomposition levels. This indicated that using these filters a very small error (approximately 7 x 10(-14)) can be achieved between original and the filtered image. The PSNR values obtained were higher for the brain than the abdomen images. For both the lossy and lossless compression, the 'most appropriate' wavelet filter should be chosen adaptively depending on the statistical properties of the image being coded to achieve higher compression ratio.
Silver nanoparticles (Ag-NPs) have been established as antibacterial nanoparticles and have been innovatively developed to overcome the occurrence of antibiotic resistance in the environment. In this study, an environmentally friendly and easy method of the biosynthesis of Ag-NPs plants, mediated by aqueous extract stem extract of Entada spiralis (E. spiralis), was successfully developed. The E. spiralis/Ag-NPs samples were characterized using spectroscopy and the microscopic technique of UV-visible (UV-vis), X-ray Diffraction (XRD), Field Emission Transmission Electron Microscope (FETEM), zeta potential, and Fourier Transform Infrared (FTIR) analyses. Surface Plasmon Resonance (SPR) absorption at 400-450 nm in the UV-vis spectra established the formation of E. spiralis/Ag-NPs. The crystalline structure of E. spiralis/Ag-NPs was displayed in the XRD analysis. The small size, around 18.49 ± 4.23 nm, and spherical shape of Ag-NPs with good distribution was observed in the FETEM image. The best physicochemical parameters on Ag-NPs biosynthesis using E. spiralis extract occurred at a moderate temperature (~52.0°C), 0.100 M of silver nitrate, 2.50 g of E. spiralis dosage and 600 min of stirring reaction time. The antibacterial activity was tested against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Proteus vulgaris using an antibacterial disk diffusion assay. Based on the results, it is evident that E. spiralis/Ag-NPs are susceptible to all the bacteria and has promising potential to be applied in both the industry and medical fields.
The eminent aim for advance wound management is to provide a great impact on the quality of life. Therefore, an excellent strategy for an ideal wound dressing is being developed that eliminates certain drawbacks while promoting tissue regeneration for the prevention of bacterial invasion. The aim of this study is to develop a bilayer hybrid biomatrix of natural origin for wound dressing. The bilayer hybrid bioscaffold was fabricated by the combination of ovine tendon collagen type I and palm tree-based nanocellulose. The fabricated biomatrix was then post-cross-linked with 0.1% (w/v) genipin (GNP). The physical characteristics were evaluated based on the microstructure, pore size, porosity, and water uptake capacity followed by degradation behaviour and mechanical strength. Chemical analysis was performed using energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectrophotometry (FTIR), and X-ray diffraction (XRD). The results demonstrated a uniform interconnected porous structure with optimal pore size ranging between 90 and 140 μm, acceptable porosity (>70%), and highwater uptake capacity (>1500%). The biodegradation rate of the fabricated biomatrix was extended to 22 days. Further analysis with EDX identified the main elements of the bioscaffold, which contains carbon (C) 50.28%, nitrogen (N) 18.78%, and oxygen (O) 30.94% based on the atomic percentage. FTIR reported the functional groups of collagen type I (amide A: 3302 cm-1, amide B: 2926 cm-1, amide I: 1631 cm-1, amide II: 1547 cm-1, and amide III: 1237 cm-1) and nanocellulose (pyranose ring), thus confirming the presence of collagen and nanocellulose in the bilayer hybrid scaffold. The XRD demonstrated a smooth wavy wavelength that is consistent with the amorphous material and less crystallinity. The combination of nanocellulose with collagen demonstrated a positive effect with an increase of Young's modulus. In conclusion, the fabricated bilayer hybrid bioscaffold demonstrated optimum physicochemical and mechanical properties that are suitable for skin wound dressing.
In the present study, CMSS (carboxymethyl sago starch)-based hydrogel was synthesized by crosslinking with citric acid via esterification and then applied as a metal sorbent to overcome excessive heavy metal pollution. The CMSS/CA (carboxymethyl sago starch/citric acid) hydrogel was characterized by Fourier Transform Infrared (FT-IR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The absorption band at 1726 cm-1 was observed in the FT-IR spectrum of CMSS/CA hydrogel and indicated ester bonds formed. Further findings show that the cross-linkages in the CMSS/CA hydrogel increased the thermal stability of CMSS and various sizes of pores were also shown in the SEM micrograph. Conversely, the removal of heavy metals was analyzed using Inductively Coupled Plasma-Optic Emission Spectra (ICP-OES). The effects of the pH of the metal solution, contact time, initial concentration of the metal ions and temperature on the sorption capacity were investigated. Under optimum condition, the sorption capacity of Pb2+, Cu2+, Ni2+ and Zn2+ onto CMSS/CA hydrogel were 64.48, 36.56, 16.21, 18.45 mg/g, respectively. The experiments demonstrated that CMSS/CA hydrogel has high selectivity towards Pb2+ in both non-competitive and competitive conditions. In conclusion, the CMSS/CA hydrogel as a natural based heavy metal sorption material exhibited a promising performance, especially in the sorption of Pb2+ for wastewater treatment.
In the contemporary medical model world, the proniosomal system has been serving as a new drug delivery system that is considered to significantly enhance the bioavailability of drugs with low water solubility. The application of this system can improve the bioavailability of aceclofenac that is used for the relief of pain and inflammation in osteoarthritis, rheumatoid arthritis, and ankylosing spondylitis. The present study is intended to develop an optimized proniosomal aceclofenac formula by the use of different carriers. Aceclofenac proniosomes have been prepared by slurry method, and different carriers such as maltodextrin, mannitol, and glucose were tried. Prepared proniosomes characterized by differential scanning calorimetry (DSC) analysis and Fourier transform infrared (FTIR) analysis revealed the compatibility of the drug chosen with the ingredient added, powder X-ray diffractometry (XRD) confirmed the amorphous phase of the prepared proniosomes, and finally, the surfactant layer was observed by scanning electron microscopy (SEM). Aceclofenac physical state transformations were confirmed with all formulas but maltodextrin proniosomes exhibited solubility more than other formulations. HPLC method has been used to analyze the niosomes derived from proniosomes in terms of their entrapment capability and drug content. The obtained results revealed that aceclofenac proniosomes can be successfully prepared by using different carriers.
The aim of this study was to investigate the potential of treated rice husk ash (RHA) as adsorbent to adsorb acidic SO2 gas. The treated RHA was prepared using a water hydration method by mixing the RHA, Calcium oxide (CaO) and Sodium Hydroxide (NaOH). The addition of NaOH is to increase the dissolution of silica from the RHA to form reactive species responsible for higher desulfurization activity. The untreated and treated RHA were subjected to several characterizations and the characteristics of the adsorbents were compared. The functional groups present on the surface of the adsorbent were determined using Fourier Transform Infrared (FTIR). The chemical composition of the untreated and treated RHA was analyzed by using X-ray Fluorescence (XRF). Scanning electron microscope (SEM) analysis showed that the treated RHA has higher porosity compared to untreated RHA. Based on the SO2 adsorption analysis, it was found that the treated RHA has higher adsorption capacity, 62.22 mg/g, compared to untreated RHA, 1.49 mg/g.
Biodiesel, one of the renewable energy sources has gained attention for decades as the alternative fuel due to its remarkable properties. However, there are several drawbacks from the industrial production of biodiesel such as the spike in the production cost, environmental issues related to the usage of homogeneous catalyst and profitability in long term. One of the solutions to eliminate the problem is by utilizing low cost starting material such as palm fatty acid distillate (PFAD). PFAD is a byproduct from the refining of crude palm oil and abundantly available. Esterification of PFAD to biodiesel will be much easier with the presence of heterogeneous acid catalyst. Most of acid catalyst preparation involves series of heating process using conventional method. In this study, microwave was utilized in catalyst preparation, significantly reducing the reaction time from conventional heating method. The catalyst produced was characterized using X-Ray Diffraction (XRD), Brunauer Emmet and Teller (BET), Scanning Electron Microscopy (SEM), Temperature-Programmed Desorption - Ammonia (TPD-NH3) and Fourier Transform Infrared (FTIR) while percentage yield and conversion of the PFAD were analysed by gas chromatography - flame ionization detector (GC-FID) and acid-base titration, respectively. It has been demonstrated that the percentage yield of biodiesel from the PFAD by employing sulfonated glucose acid catalyst (SGAC) reached 98.23% under the following conditions: molar ratio of methanol to PFAD of 10:1, catalyst loading of 2.5% and reaction temperature of 70oC. The microwave-assisted SGAC showed its potential to replace the SGAC produced via conventional heating method.
Scaffolds supplemented with naturally derived materials seem to be a good choice in bone tissue engineering. This study aims to develop polyurethane (PU) nanofibers added with ylang ylang (YY) and zinc nitrate (ZnNO3) using the electrospinning method. Field emission scanning electron microscopy (FESEM) images showed that the diameter of the PU nanofibers (869 ± 122 nm) was reduced with the addition of YY and ZnNO3 (PU/YY-467 ± 132 nm and PU/YY/ZnNO3-290 ± 163 nm). Fourier transform infrared (FTIR), a thermal gravimetric analysis (TGA) and an X-ray diffraction (XRD) analysis confirmed the interactions between PU with YY and ZnNO3. In addition, a thermal gravimetric analysis (TGA) study revealed the improved thermal stability for PU/YY and a slight reduction in the thermal stability for PU/YY/ZnNO3. A tensile test indicated that the addition of YY and ZnNO3 (PU/YY-12.32 MPa and PU/YY/ZnNO3-14.90 MPa) improved the mechanical properties of the pristine PU (6.83 MPa). The electrospun PU/YY (524 nm) and PU/YY/ZnNO3 (284 nm) showed a reduced surface roughness when compared with the pristine PU (776 nm) as depicted in the atomic force microscopy (AFM) analysis. The addition of YY and ZnNO3 improved the anticoagulant and biocompatibility nature of the pristine PU. Furthermore, the bone mineralization study depicted the improved calcium deposition in the fabricated composites (PU/YY-7.919% and PU/YY/ZnNO3-10.150%) compared to the pristine PU (5.323%). Hence, the developed composites with desirable physico-chemical properties, biocompatibility and calcium deposition can serve as plausible candidates for bone tissue engineering.
This study was driven by the stringent environmental legislation concerning the consumption and utilization of eco-friendly materials. Within this context, this paper aimed to examine the characteristics of starch and fibres from the Dioscorea hispida tuber plant to explore their potential as renewable materials. The extraction of the Dioscorea hispida starch and Dioscorea hispida fibres was carried out and the chemical composition, physical, thermal, morphological properties, and crystallinity were studied. The chemical composition investigations revealed that the Dioscorea hispida starch (DHS) has a low moisture t (9.45%) and starch content (37.62%) compared to cassava, corn, sugar palm, and arrowroot starches. Meanwhile, the Dioscorea hispida fibres (DHF) are significantly low in hemicellulose (4.36%), cellulose (5.63%), and lignin (2.79%) compared to cassava, corn hull and sugar palm. In this investigation the chemical, physical, morphological and thermal properties of the Dioscorea hispida fibre and Dioscorea hispida starch were examined by chemical composition investigation, scanning electron microscopy (SEM), particle size distribution, thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), and Fourier transform infrared (FTIR), respectively. It was found that Dioscorea hispida waste is promising alternative biomass and sustainable material with excellent potential as a renewable filler material for food packaging applications.
Glass ionomer cement (GIC) is a well-known restorative material applied in dentistry. The present work aims to study the effect of hydroxyapatite (HA) addition into GIC based on physical, mechanical and structural properties. The utilization of waste materials namely clam shell (CS) and soda lime silica (SLS) glass as replacements for the respective CaO and SiO2 sources in the fabrication of alumino-silicate-fluoride (ASF) glass ceramics powder. GIC was formulated based on ASF glass ceramics, polyacrylic acid (PAA) and deionized water, while 1 wt.% of HA powder was added to enhance the properties of the cement samples. The cement samples were subjected to four different ageing times before being analyzed. In this study, the addition of HA caused an increment in density and compressive strength results along with ageing time. Besides, X-ray Diffraction (XRD) revealed the formation of fluorohydroxyapatite (FHA) phase in HA-added GIC samples and it was confirmed by Fourier Transform Infrared (FTIR) analysis which detected OH‒F vibration mode. In addition, needle-like and agglomeration of spherical shapes owned by apatite crystals were observed from Field Emission Scanning Electron Microscopy (FESEM). Based on Energy Dispersive X-ray (EDX) analysis, the detection of chemical elements in the cement samples were originated from chemical compounds used in the preparation of glass ceramics powder and also the polyacid utilized in initiating the reaction of GIC.
There is an interest in the sustainable utilization of waste cotton cloths because of their enormous volume of generation and high cellulose content. Waste cotton cloths generated are disposed of in a landfill, which causes environmental pollution and leads to the waste of useful resources. In the present study, cellulose nanocrystals (CNCs) were isolated from waste cotton cloths collected from a landfill. The waste cotton cloths collected from the landfill were sterilized and cleaned using supercritical CO2 (scCO2) technology. The cellulose was extracted from scCO2-treated waste cotton cloths using alkaline pulping and bleaching processes. Subsequently, the CNCs were isolated using the H2SO4 hydrolysis of cellulose. The isolated CNCs were analyzed to determine the morphological, chemical, thermal, and physical properties with various analytical methods, including attenuated total reflection-Fourier transform-infrared spectroscopy (ATR-FTIR), field-emission scanning electron microscopy (FE-SEM), energy-filtered transmission electron microscopy (EF-TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results showed that the isolated CNCs had a needle-like structure with a length and diameter of 10-30 and 2-6 nm, respectively, and an aspect ratio of 5-15, respectively. Additionally, the isolated CNCs had a high crystallinity index with a good thermal stability. The findings of the present study revealed the potential of recycling waste cotton cloths to produce a value-added product.