In this study, we propose an innovative, bio-based, environmentally friendly approach for the covalent functionalization of multi-walled carbon nanotubes using clove buds. This approach is innovative because we do not use toxic and hazardous acids which are typically used in common carbon nanomaterial functionalization procedures. The MWCNTs are functionalized in one pot using a free radical grafting reaction. The clove-functionalized MWCNTs (CMWCNTs) are then dispersed in distilled water (DI water), producing a highly stable CMWCNT aqueous suspension. The CMWCNTs are characterized using Raman spectroscopy, X-ray photoelectron spectroscopy and transmission electron microscopy. The electrostatic interactions between the CMWCNT colloidal particles in DI water are verified via zeta potential measurements. UV-vis spectroscopy is also used to examine the stability of the CMWCNTs in the base fluid. The thermo-physical properties of the CMWCNT nano-fluids are examined experimentally and indeed, this nano-fluid shows remarkably improved thermo-physical properties, indicating its superb potential for various thermal applications.
Congenital myopathy is a broad category of muscular diseases with symptoms appearing at the time of birth. One type of congenital myopathy is Congenital Fiber Type Disproportion (CFTD), a severely debilitating disease. The G48D and G48C mutations in the D-loop and the actin-myosin interface are the two causes of CFTD. These mutations have been shown to significantly affect the structure and function of muscle fibers. To the author's knowledge, the effects of these mutations have not yet been studied. In this work, the power stroke structure of the head domain of myosin and the wild and mutated types of actin were modeled. Then, a MD simulation was run for the modeled structures to study the effects of these mutations on the structure, function, and molecular dynamics of actin. The wild and mutated actins docked with myosin showed differences in hydrogen bonding patterns, free binding energies, and hydrogen bond occupation frequencies. The G48D and G48C mutations significantly impacted the conformation of D-loops because of their larger size compared to Glycine and their ability to interfere with the polarity or hydrophobicity of this neutralized and hydrophobic loop. Therefore, the mutated loops were unable to fit properly into the hydrophobic groove of the adjacent G-actin. The abnormal structure of D-loops seems to result in the abnormal assembly of F-actins, giving rise to the symptoms of CFTD. It was also noted that G48C and G48D did not form hydrogen bonds with myosin in the residue 48 location. Nevertheless, in this case, muscles are unable to contract properly due to muscle atrophy.
The epithelial-mesenchymal transition (EMT) is a crucial process in cancer progression and metastasis. Study of metabolic changes during the EMT process is important in seeking to understand the biochemical changes associated with cancer progression, not least in scoping for therapeutic strategies aimed at targeting EMT. Due to the potential for high sensitivity and specificity, Raman spectroscopy was used here to study the metabolic changes associated with EMT in human breast cancer tissue. For Raman spectroscopy measurements, tissue from 23 patients were collected, comprising non-lesional, EMT and non-EMT formalin-fixed and paraffin embedded breast cancer samples. Analysis was made in the fingerprint Raman spectra region (600-1800 cm-1) best associated with cancer progression biochemical changes in lipid, protein and nucleic acids. The ANOVA test followed by the Tukey's multiple comparisons test were conducted to see if there existed differences between non-lesional, EMT and non-EMT breast tissue for Raman spectroscopy measurements. Results revealed that significant differences were evident in terms of intensity between the non-lesional and EMT samples, as well as the EMT and non-EMT samples. Multivariate analysis involving independent component analysis, Principal component analysis and non-negative least square were used to analyse the Raman spectra data. The results show significant differences between EMT and non-EMT cancers in lipid, protein, and nucleic acids. This study demonstrated the capability of Raman spectroscopy supported by multivariate analysis in analysing metabolic changes in EMT breast cancer tissue.
Collagen was extracted from the body wall of sea cucumber (Holothuria scabra) using the pepsin-solubilized collagen method followed by isolation using dialysis and the ultrafiltration membrane. The yield and physicochemical properties of the collagen obtained from both isolation methods, denoted as D-PSC and UF-PSC, were compared. The ultrafiltration method affords a higher yield of collagen (11.39%) than that of the dialysis (5.15%). The isolated collagens have almost the same amino acid composition, while their functional groups, referred to as amide A, B, I, II, and III bands, were in accordance with commercial collagen, as verified by Fourier Transform Infrared (FT-IR) spectroscopy. The UV-Vis absorption peaks at 240 nm and 220 nm, respectively, indicated that the collagens produced are type-I collagen. The D-PSC showed interconnecting sheet-like fibrils, while the UF-PSC exhibited a flaky structure with flat-sheets arranged very close to each other. The higher yield and comparable physicochemical properties of the collagen obtained by ultrafiltration as compared with dialysis indicate that the membrane process has high potential to be used in large-scale collagen production for food and pharmaceutical applications.
A series of hydrogenated amorphous carbon (a-C:H) thin films were deposited using home-built direct-current (DC) plasma enhanced chemical vapour deposition (PECVD) system. In this present study, the a-C:H thin films were deposited using pure methane (CH4) gas diluted either with hydrogen (H) or helium (He). The effects of hydrogen and helium dilution on the photoluminescence (PL) properties and optical band gap (E04) were studied. The dependence of PL properties and optical energy gap on the film thickness has also been investigated. The characterization techniques used were optical transmission and photoluminescence spectroscopies. The sp2 cluster sizes were determined from Raman spectra are in the range of 5 to 7 nm. Hydrogen and helium dilution of methane strongly influences the PL efficiency of the a-C:H films. The PL efficiency are enhanced with increase in film thickness for a-C:H films prepared both from H and He diluted CH4. The optical energy gap of these films decreases with increase in H or He dilution and film thickness.
We have calculated the vibrational frequencies of clusters of atoms from the first principles by using the density-functional theory in the local density approximation (LDA). We are also able to calculate the electronic binding energy for all of the clusters of atoms from the optimized structure. We have made clusters of BanOm (n, m=1-6) and have determined the bond lengths, vibrational frequencies as well as intensities in each case. We find that the peroxide cluster BaO2 occurs with the O-O vibrational frequency of 836.3 cm(-1). We also find that a glass network occurs in the material which explains the vibrational frequency of 67 cm(-1). The calculated values agree with those measured from the Raman spectra of barium peroxide and Ba-B-oxide glass. We have calculated the vibrational frequencies of BaO4, GeO4 and SiO4 each in tetrahedral configuration and find that the vibrational frequencies in these systems depend on the inverse square root of the atomic mass.
Halal is an Arabic term used to describe any components allowed to be used in any products by Muslim communities. Halal food and halal pharmaceuticals are any food and pharmaceuticals which are safe and allowed to be consumed according to Islamic law (Shariah). Currently, in line with halal awareness, some Muslim countries such as Indonesia, Malaysia, and Middle East regions have developed some standards and regulations on halal products and halal certification. Among non-halal components, the presence of pig derivatives (lard, pork, and porcine gelatin) along with other non-halal meats (rat meat, wild boar meat, and dog meat) is typically found in food and pharmaceutical products. This review updates the recent application of molecular spectroscopy, including ultraviolet-visible, infrared, Raman, and nuclear magnetic resonance (NMR) spectroscopies, in combination with chemometrics of multivariate analysis, for analysis of non-halal components in food and pharmaceutical products. The combination of molecular spectroscopic-based techniques and chemometrics offers fast and reliable methods for screening the presence of non-halal components of pig derivatives and non-halal meats in food and pharmaceutical products.
In this study, zinc oxide (ZnO) nanorod arrays were synthesized using a simple hydrothermal reaction on ZnO seeds/n-silicon substrate. Several parameters were studied, including the heat-treatment temperature to produce ZnO seeds, zinc nitrate concentration, pH of hydrothermal reaction solution, and hydrothermal reaction time. The optimum heat-treatment temperature to produce uniform nanosized ZnO seeds was 400°C. The nanorod dimensions depended on the hydrothermal reaction parameters. The optimum hydrothermal reaction parameters to produce blunt tip-like nanorods (770 nm long and 80 nm in top diameter) were 0.1 M zinc nitrate, pH 7, and 4 h of growth duration. Phase analysis studies showed that all ZnO nanorods exhibited a strong (002) peak. Thus, the ZnO nanorods grew in a c-axis preferred orientation. A strong ultraviolet (UV) emission peak was observed for ZnO nanorods grown under optimized parameters with a low, deep-level emission peak, which indicated high optical property and crystallinity of the nanorods. The produced ZnO nanorods were also tested for their UV-sensing properties. All samples responded to UV light but with different sensing characteristics. Such different responses could be attributed to the high surface-to-volume ratio of the nanorods that correlated with the final ZnO nanorods morphology formed at different synthesis parameters. The sample grown using optimum synthesis parameters showed the highest responsivity of 0.024 A/W for UV light at 375 nm under a 3 V bias.
Introduction: Application of nano-engineered fingerprint dusting powders has been a recent trend to achieve latent fingermark development with superior ridge clarity. As such, efforts have been made to utilise natural resources to increase the sustainability of these emerging nano-engineered powders. Lithium-doped zinc oxide, primarily used as white pigments, have been previously applied to latent fingermarks with success. In the current study, nanostruc- tured zinc oxide, synthesised using neem extract as the reducing agent, was evaluated for fingermark development on non-porous surfaces. Methods: The reduction of zinc nitrate hexahydrate was facilitated by neem extract, pre- pared by boiling neem leaves in distilled water. The thick yellow paste recovered was calcined in the furnace to produce a light yellow powder. Physicochemical composition of the powder was determined using microscopic and spectroscopic instruments. The effectiveness of the powder was tested on natural fingermark deposited on several non-porous surfaces. Results: Nanostructured zinc oxide with particle size ranging in between 1 to 3 µm consisting of highly aggregated spherical particle with less than 100 nm dimensions were synthesised. Developed fingermarks revealed excellent ridge details and contrast on dark coloured surfaces. Studying the fingermark closely under scan- ning electron microscope displayed selective distribution of particle on the ridges of the fingermark residue and very minimal deposition on the fingermark valleys. Conclusion: Nanostructured zinc oxide fabricated using green chem- istry approach can be applied for the development of fingermark. Nevertheless, future works can be undertaken to enhance particle dispersity and to confer strong photoluminescence to the zinc oxide nanoparticles.
This study investigated the engine performance and emission characteristics of biodiesel blends with combined Graphene oxide nanoplatelets (GNPs) and 10% v/v dimethyl carbonate (DMC) as fuel additives as well as analysed the tribological characteristics of those blends. 10% by volume DMC was mixed with 30% palm oil biodiesel blends with diesel. Three different concentrations (40, 80 and 120 ppm) of GNPs were added to these blends via the ultrasonication process to prepare the nanofuels. Sodium dodecyl sulphate (SDS) surfactant was added to improve the stability of these blends. GNPs were characterised using Scanning Electron Microscope (SEM) and Fourier Transform Infrared (FTIR), while the viscosity of nanofuels was investigated by rheometer. UV-spectrometry was used to determine the stability of these nanoplatelets. A ratio of 1:4 GNP: SDS was found to produce maximum stability in biodiesel. Performance and emissions characteristics of these nanofuels have been investigated in a four-stroke compression ignition engine. The maximum reduction in BSFC of 5.05% and the maximum BTE of 22.80% was for B30GNP40DMC10 compared to all other tested blends. A reduction in HC (25%) and CO (4.41%) were observed for B30DMC10, while a reduction in NOx of 3.65% was observed for B30GNP40DMC10. The diesel-biodiesel fuel blends with the addition of GNP exhibited a promising reduction in the average coefficient of friction 15.05%, 8.68% and 3.61% for 120, 80 and 40 ppm concentrations compared to B30. Thus, combined GNP and DMC showed excellent potential for utilisation in diesel engine operation.
Various classification methods have been applied for low resolution of the entire Earth's surface from recorded satellite images, but insufficient study has determined which method, for which satellite data, is economically viable for tropical forest land use mapping. This study employed Iterative Self Organizing Data Analysis Techniques (ISODATA) and K-Means classification techniques to classified Moderate Resolution Imaging Spectroradiometer (MODIS) Surface Reflectance satellite image into forests, oil palm groves, rubber plantations, mixed horticulture, mixed oil palm and rubber and mixed forest and rubber. Even though frequent cloud cover has been a challenge for mapping tropical forests, our MODIS land use classification map found that 2008 ISODATA-1 performed well with overall accuracy of 94%, with the highest Producer's Accuracy of Forest with 86%, and were consistent with MODIS Land Cover 2008 (MOD12Q1), respectively. The MODIS land use classification was able to distinguish young oil palm groves from open areas, rubber and mature oil palm plantations, on the Advanced Land Observing Satellite (ALOS) map, whereas rubber was more easily distinguished from an open area than from mixed rubber and forest. This study provides insight on the potential for integrating regional databases and temporal MODIS data, in order to map land use in tropical forest regions.
In this study, a series of copper-ion-doped titanium dioxide (Cu-ion-doped TiO₂) nanotubes (NTs) were synthesized via a hydrothermal method by the concentration variation of doped Cu ions (0.00, 0.50, 1.00, 2.50, and 5.00 mmol). In addition, the samples were characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), nitrogen gas adsorption measurements, and ultraviolet-visible (UV-Vis) diffuse-reflectance spectroscopy. The photocatalytic activity of the Cu-iondoped TiO₂ NTs was investigated for the degradation of methyl orange (MO) under sunlight. The results obtained from the structural and morphological studies revealed that, at low concentrations of Cu-doped TiO₂ NTs, Cu is incorporated into the interstitial positions of the TiO₂ lattice, affording a new phase of TiO₂ (hexagonal) instead of the anatase TiO₂ (tetragonal) observed for undoped TiO₂ NTs. EDX analysis confirmed the presence of Cu in the TiO₂-based photocatalyst. All of the investigated samples exhibited a hollow fibrous-like structure, indicative of an NT morphology. The inner and outer diameters of the NTs were 4 nm and 10 nm, respectively. The photocatalysts exhibited a large surface area due to the NT morphology and a type IV isotherm and H3 hysteresis, corresponding to the mesopores and slit-shaped pores. The Cu-ion-doped TiO₂ NTs were excited by sunlight because of their low bandgap energy; and after the incorporation of Cu ions into the interstitial positions of the TiO₂ lattice, the NTs exhibited high visible-light activity owing to the low bandgap.
Anatase titanium dioxide nanoparticles (TiO2-NPs) were synthesized by sol-gel method using rice straw as a soft biotemplate. Rice straw, as a lignocellulosic waste material, is a biomass feedstock which is globally produced in high rate and could be utilized in an innovative approach to manufacture a value-added product. Rice straw as a reliable biotemplate has been used in the sol-gel method to synthesize ultrasmall sizes of TiO2-NPs with high potential application in photocatalysis. The physicochemical properties of titanium dioxide nanoparticles were investigated by a number of techniques such as X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, thermogravimetric analysis (TGA), ultraviolet visible spectra (UV-Vis), and surface area and pore size analysis. All results consensually confirmed that particle sizes of synthesized titanium dioxide were template-dependent, representing decrease in the nanoparticles sizes with increase of biotemplate concentration. Titanium dioxide nanoparticles as small as 13.0 ± 3.3 nm were obtained under our experimental conditions. Additionally, surface area and porosity of synthesized TiO2-NPs have been enhanced by increasing rice straw amount which results in surface modification of nanoparticles and potential application in photocatalysis.
Microbial pigments are gaining intensive attention due to increasing awareness of the toxicity of synthetic colours. In this study, a novel polymer-producing bacterium designated as Cupriavidus sp. USMAHM13 was also found to produce yellow pigment when cultivated in nutrient broth. Various parameters such as temperature, pH and ratio of culture volume to flask volume were found to influence the yellow pigment production. UV-Visible, Fourier transform infrared and (13)C-nuclear magnetic resonance analyses revealed that the crude yellow pigment might probably represent new bioactive compound in the carotenoid family. The crude yellow pigment also exhibited a wide spectrum of antimicrobial activity against Gram-negative and Gram-positive bacteria with their inhibition zones and minimal inhibitory concentrations ranged from 25 to 38 mm and from 0.63 to 2.5 mg/ml, respectively. To the best of our knowledge, this is the first report on the identification and characterization of yellow pigment produced by bacterium belonging to the genus Cupriavidus.
Seven flavonoid compounds have been isolated from the aerial parts of tiger's betel (Piper porphyrophyllum), which were identified as 5,7-dimethoxyflavone, 4',5,7-trimethoxy-flavone, 3',4',5,7-tetramethoxyflavone, 4'-hydroxy-3',5,7-trimethoxyflavone, 5-hydroxy-3',4',7-trimethoxyflavone, 4',5-dihydroxy-3',7-dimethoxyflavone and 5-hydroxy-7-methoxyflavanone. The identification of all compounds was achieved by physical properties and spectroscopically. These data were also confirmed by comparison with previously reported spectral data. Flavonoid compounds with high content in P. porphyrophyllum can probably be used as a chemical marker for this Piper species.
In this paper, the structural and optical properties of ZnO-SiO2-based ceramics fabricated from oil palm empty fruit bunch (OPEFB) were investigated. The OPEFB waste was burned at 600, 700 and 800 °C to form palm ash and was then treated with sulfuric acid to extract silica from the ash. X-ray fluorescence (XRF) and X-ray diffraction (XRD) analyses confirmed the existence of SiO2 in the sample. Field emission scanning electron microscopy (FESEM) showed that the particles displayed an irregular shape and became finer after leaching. Then, the solid-state method was used to produce the ZnO-SiO2 composite and the samples were sintered at 600, 800, 1000, 1200 and 1400 °C. The XRD peaks of the Zn2SiO4 showed high intensity, which indicated high crystallinity of the composite. FESEM images proved that the grain boundaries were larger as the temperature increased. Upon obtaining the absorbance spectrum from ultraviolet-visible (UV-Vis) spectroscopy, the energy band gaps obtained were 3.192, 3.202 and 3.214 eV at room temperature, 600 and 800 °C, respectively, and decreased to 3.127, 2.854 and 2.609 eV at 1000, 1200 and 1400 °C, respectively. OPEFB shows high potential as a silica source in producing promising optical materials.
The study and applications of in vivo skin optics have been openly documented as early as the year 1954, or possibly earlier. To date, challenges in analyzing the complexities of this field remain, with wide scopes requiring more scrutiny. Recent advances in spectroscopic research and multivariate analytics allow a closer look into applications potentially for detecting or monitoring diseases. One of the challenges in this field is in establishing a reference for applications which correspond to certain bandwidths. This article reviews the scope on past research on skin spectroscopy, and the clinical aspects which have or may have applications on disease detection or enhancing diagnostics. A summary is supplied on the technicalities surrounding the measurements reported in literature, focused towards the wavelength-dependent applications in themes central to the respective research. Analytics on the topology of the papers' data cited in this work is also provided for a statistical perspective. In short, this paper strives to immediately inform the reader with possible applications via the spectroscopic devices at hand. Graphical Abstract .
Dengue diagnostics have come a long way. Attempts at breaking away from lab-oriented dengue detection, such as NS1 antigen, IgM or IgG antibodies detection have extensively received numerous coverage. As a result, rapid detection tests (RDTs) have started to gain inroads in medical practice. Rapid detection tests notwithstanding, analysis of blood serum is still a relatively complicated task. This includes the necessity of phlebotomy, centrifugation for blood serum, and other reagent-based tests. Therefore, a non-invasive method of dengue detection was considered. In this study, we present the utility of diffuse reflectance skin spectroscopy (bandwidth of 200-2500nm) on the forearm during the triaging period for dengue screening potential. This is performed with multivariate analysis of 240 triaged febrile/suspected dengue patients. The data is then scrutinized for its clinical validity to be included as either confirmed or probable dengue, or a control group. Based on discriminant analysis of several data normalization models, we can predict the patients' clinical dengue-positivity at ranges of accuracy between ~93-98% depending on mode of the data, with a probably optimal sensitivity and specificity to the clinical diagnosis of ~89% and ~100% respectively. From the outcomes of this study, we recommend further trials with cautious optimism. With these findings, it is hoped that the elusive non-invasive detection of tropical diseases may gain platform in the near future.
Objective: To delineate and differentiate between late subacute hemorrhage and intracranial lipomas in clinically available conventional and advanced MR sequences. Methods: Two cases of late subacute hemorrhage and two cases of intracranial lipoma were reviewed with CT scans and 3.0T scanner MRI. The sequences evaluated in MRI were T1-weighted (T1W) fast spin echo (FSE), T2-weighted (T2W) FSE, gradient echo T2*-weighted (GRE T2*W) images, diffusion weighted (DWI), apparent diffusion coefficient (ADC) and multivoxel spectroscopy. Results: Late subacute hemorrhage and intracranial lipoma have similar imaging features on T1W, T2W FSE with blooming artefact at the margins on GRE T2*W. However on GRE T2*W sequence, the central area of lipoma demonstrates low signal; while hemorrhage demonstrates high signal. In DWI, late subacute hemorrhage shows hyperintensity; while in lipoma there is loss of signal.
Conclusion: Awareness of the potential pitfalls in standard sequence are important, as these entities appear to have similar T1W/ T2W characteristic with blooming artefact on T2*W. Knowing the distinctive central signal intensity pattern on GRE T2W* and DWI is therefore essential to differentiate between these lesions as there are differences to their clinical management.