Displaying publications 61 - 80 of 317 in total

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  1. Characterization of natural fiber obtained from different parts of date palm tree (Phoenix dactylifera L.)
    Alotaibi MD, Alshammari BA, Saba N, Alothman OY, Sanjay MR, Almutairi Z, et al.
    Int J Biol Macromol, 2019 Aug 15;135:69-76.
    PMID: 31116962 DOI: 10.1016/j.ijbiomac.2019.05.102
    The current study is motivated by the strict environmental regulations regarding the utilization and consumption of ecofriendly materials. In this context, the aim of this study has been to prepare and characterize different date palm tree (Phoenix dactylifera L.) fibers processed through the conventional water retting method. The chemical, elemental, crystallinity, thermal and morphological characterization of trunk (DPTRF), leaf stalk (DPLST), sheath or leaf sheath (DPLSH) and fruit bunch stalk (DPFBS) fibers was carried out. Chemical analysis revealed that the four types of date palm fibers display noteworthy differences in the content of cellulose, hemicellulose and lignin. Also, the amount of calcium is relatively high in all the date palm fibers; besides this, DPTRF exhibited 69.2% crystallinity, which is lower than that of DPLSH with 72.4% crystallinity. Moreover, DPLST and DPFBS fibers are more thermally stable (higher thermal degradation temperature) than DPTRF and DPLSH samples. Morphological analysis revealed that the fracture surface of DPFBS was relatively rougher, which would probably lead to increased bonding strength with polymers in composites. Overall, we conclude that DPFBS would be promising alternative sustainable and biomass material for the isolation of respective cellulose nanofibers and cellulose nanocrystals as potential reinforcement in polymer composites.
    Matched MeSH terms: Spectrum Analysis
  2. Characterization of raw and alkali treated new natural cellulosic fibers from Tridax procumbens
    Vijay R, Lenin Singaravelu D, Vinod A, Sanjay MR, Siengchin S, Jawaid M, et al.
    Int J Biol Macromol, 2019 Mar 15;125:99-108.
    PMID: 30528990 DOI: 10.1016/j.ijbiomac.2018.12.056
    The aim of this study is to investigate natural cellulosic fibers extracted from Tridax procumbens plants. The obtained fibers were alkali treated for their effective usage as reinforcement in composites. The physical, chemical, crystallinity, thermal, wettability and surface characteristics were analyzed for raw, and alkali treated Tridax procumbens fibers (TPFs). The test results conclude that there was an increase in cellulose content with a reduction in hemicellulose, lignin, and wax upon alkali treatment. This enhanced the thermal stability, tensile strength, crystallinity, and surface roughness characteristics. The contact angle was also lesser for treated TPFs which prove its better wettability with the liquid phase. The Weibull distribution analysis was adopted for the analysis of the fiber diameter and tensile properties. Thus the considerable improvement in the properties of alkali treated TPFs would be worth for developing high-performance polymer composites.
    Matched MeSH terms: Spectrum Analysis
  3. Chemical components of marine sponge derived fungus fusarium proliferatum collected from Pulau Tinggi, Malaysia
    Mosadeghzad Z, Zuriati Zakaria, Asmat A, Gires U, Wickneswari R, Pittayakhajonwut P, et al.
    Sains Malaysiana, 2012;41:333-337.
    Marine fungus Fusarium proliferatum derived from marine sponge collected along Pulau Tinggi, Malaysia was cultivated on Potato Dextrose Broth and incubated for 7 days at 30oC. The liquid cultures were then extracted using ethyl acetate. The crude extract was investigated for its anti-microbial activity and was passed through Sephadex column and the fractions were collected. Reverse phase HPLC was used to monitor the component of crude extract. HPLC guided purification of crude extract resulted in the isolation of linoleic acid, 4-hydroxy phenethyl alcohol, 2,5-furandimethanol and adenosine. Their structures were elucidated by spectroscopic methods.
    Matched MeSH terms: Spectrum Analysis
  4. Chemical constituents from tiger's betel, Piper porphyrophyllum N.E.Br. (Fam. Piperaceae)
    Rajudin E, Ahmad F, Sirat HM, Arbain D, Aboul-Enein HY
    Nat Prod Res, 2010 Mar;24(4):387-90.
    PMID: 20221945 DOI: 10.1080/14786410903421826
    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.
    Matched MeSH terms: Spectrum Analysis/methods
  5. Fulltext Chemical profile of Xanthine Oxidase inhibitor fraction of Persicaria Hydropiper
    Noor Hashim, N.H., Maulidiani, M., Mediani, A., Abas, F.
    International Food Research Journal, 2018;25(3):1088-1094.
    MyJurnal
    Persicaria hydropiper, locally known as kesum, is an herb belongs to the family Polygonaceae. It has been used widely in many countries as food flavoring and possesses a wide range of medicinal values. The total phenolic content and xanthine oxidase inhibitory activity of the methanolic extract of P. hydropiper and fractions were determined spectrophotometrically. The butanol fraction was found to contain high phenolic content and was able to inhibit xanthine oxidase activity. Online profiling using liquid chromatography coupled with electrospray ionisation spectrometry (LC-ESIMS/MS) has revealed ten constituents in this active fraction. The major components were flavonoid derivatives and flavonoid sulphates, which were confirmed by comparison with an authentic standards as well as their MS/MS fragmentation patterns and UV spectra.
    Matched MeSH terms: Spectrum Analysis
  6. Chemically modified multi-walled carbon nanotubes (MWCNTs) with anchored acidic groups
    Nuruzatulifah Bt Asari @ Mansor, Tessonnier JP, Rinaldi A, Reiche S, Kutty M
    Sains Malaysiana, 2012;41:603-609.
    Surface functionalization of multi-walled carbon nanotubes (MWCNTs) was carried out using a gas phase treatment in a Universal Temperature Program (UTP) reactor by flowing SO3 gas onto the CNTs while being heated at different temperatures. The functionalized nanotubes were characterized using X-ray Fluorescence (XRF), Fourier Transform Infrared Spectroscopy (FT-IR) and Raman spectroscopy. The amount of oxyen and sulfur containing groups was determined by acid-base titration. The titration results were in good agreement with elemental analysis using x-ray fluorescence. FTIRanalysis showed the presence of oxygen and sulfur containing groups, S=O, C-S, C=O and -COOH. Raman spectroscopy confirmed that oxygen and sulfur containing acidic groups covalently attached to the sidewall of the MWCNTs.
    Matched MeSH terms: Spectrum Analysis, Raman
  7. Chemometrics analysis for the detection of dental caries via UV absorption spectroscopy
    Basri KN, Yazid F, Megat Abdul Wahab R, Mohd Zain MN, Md Yusof Z, Zoolfakar AS
    Spectrochim Acta A Mol Biomol Spectrosc, 2022 Feb 05;266:120464.
    PMID: 34634732 DOI: 10.1016/j.saa.2021.120464
    Caries is one of the non-communicable diseases that has a high prevalence trend. The current methods used to detect caries require sophisticated laboratory equipment, professional inspection, and expensive equipment such as X-ray imaging device. A non-invasive and economical method is required to substitute the conventional methods for the detection of caries. UV absorption spectroscopy coupled with chemometrics analysis has emerged as a good potential candidate for such an application. Data preprocessing methods such as mean centre, autoscale and Savitzky-Golay smoothing were implemented to enhance the signal-to-noise ratio of spectra data. Various classification algorithms namely K-nearest neighbours (KNN), logistic regression (LR) and linear discriminant analysis (LDA) were implemented to classify the severity of dental caries into International Caries Detection and Assessment System (ICDAS) scores. The performance of the prediction model was measured and comparatively analysed based on the accuracy, precision, sensitivity, and specificity. The LDA algorithm combined with the Savitzky-Golay preprocessing method had shown the best result with respect to the validation data accuracy, precision, sensitivity and specificity, where each had values of 0.90, 1.00, 0.86 and 1.00 respectively. The area under the curve of the ROC plot computed for the LDA algorithm was 0.95, which indicated that the prediction algorithm was capable of differentiating normal and caries teeth excellently.
    Matched MeSH terms: Spectrum Analysis
  8. Chitosan based thermosensitive injectable hydrogels for controlled delivery of loxoprofen: development, characterization and in-vivo evaluation
    Ahmad U, Sohail M, Ahmad M, Minhas MU, Khan S, Hussain Z, et al.
    Int J Biol Macromol, 2019 May 15;129:233-245.
    PMID: 30738157 DOI: 10.1016/j.ijbiomac.2019.02.031
    Oral drug delivery is natural, most acceptable and desirable route for nearly all drugs, but many drugs like NSAIDs when delivered by this route cause gastrointestinal irritation, gastric bleeding, ulcers, and many undesirable effects which limits their usage by oral delivery. Moreover, it is almost impossible to control the release of a drug in a targeted location in body. We developed thermo-responsive chitosan-co-poly(N-isopropyl-acrylamide) injectable hydrogel as an alternative for the gastro-protective and controlled delivery of loxoprofen sodium as a model drug. A free radical polymerization technique was used to synthesize thermo-responsive hydrogel by cross-linking chitosan HCl with NIPAAM using glutaraldehyde as cross-linker. Confirmation of crosslinked hydrogel structure was done by Fourier transform infrared spectra (FTIR). The thermal stability of hydrogel was confirmed through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The scanning electron microscopy (SEM) was performed to evaluate the structural morphology of cross-linked hydrogel. To evaluate the rheological behavior of hydrogel with increasing temperature, rheological study was performed. Swelling and in vitro drug release studies were carried out under various temperature and pH conditions. The swelling study revealed that maximum swelling was observed at low pH (pH 1.2) and low temperature (25 °C) compared to the high range of pH and temperature and it resulted in quick release of the drug. The high range of pH (7.4) and temperature (37 °C) however caused controlled release of the drug. The in vivo evaluation of the developed hydrogel in rabbits demonstrated the controlled release behavior of fabricated system.
    Matched MeSH terms: Spectrum Analysis
  9. Cholinesterase inhibitory activity of isoquinoline alkaloids from three Cryptocarya species (Lauraceae)
    Wan Othman WNN, Liew SY, Khaw KY, Murugaiyah V, Litaudon M, Awang K
    Bioorg Med Chem, 2016 09 15;24(18):4464-4469.
    PMID: 27492195 DOI: 10.1016/j.bmc.2016.07.043
    Alzheimer's disease is the most common form of dementia among older adults. Acetylcholinesterase and butyrylcholinesterase are two enzymes involved in the breaking down of the neurotransmitter acetylcholine. Inhibitors for these enzymes have potential to prolong the availability of acetylcholine. Hence, the search for such inhibitors especially from natural products is needed in developing potential drugs for Alzheimer's disease. The present study investigates the cholinesterase inhibitory activity of compounds isolated from three Cryptocarya species towards acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Nine alkaloids were isolated; (+)-nornantenine 1, (-)-desmethylsecoantofine 2, (+)-oridine 3, (+)-laurotetanine 4 from the leaves of Cryptocarya densiflora BI., atherosperminine 5, (+)-N-methylisococlaurine 6, (+)-N-methyllaurotetanine 7 from the bark of Cryptocarya infectoria Miq., 2-methoxyatherosperminine 8 and (+)-reticuline 9 from the bark of Cryptocarya griffithiana Wight. In general, most of the alkaloids showed higher inhibition towards BChE as compared to AChE. The phenanthrene type alkaloid; 2-methoxyatherosperminine 8, exhibited the most potent inhibition against BChE with IC50 value of 3.95μM. Analysis of the Lineweaver-Burk (LB) plot of BChE activity over a range of substrate concentration suggested that 2-methoxyatherosperminine 8 exhibited mixed-mode inhibition with an inhibition constant (Ki) of 6.72μM. Molecular docking studies revealed that 2-methoxyatherosperminine 8 docked well at the choline binding site and catalytic triad of hBChE (butyrylcholinesterase from Homo sapiens); hydrogen bonding with Tyr 128 and His 438 residues respectively.
    Matched MeSH terms: Spectrum Analysis/methods
  10. Clinical and radiographic periodontal parameters and release of collagen degradation biomarkers in naswar dippers
    Daood U, Abduljabbar T, Al-Hamoudi N, Akram Z
    J Periodontal Res, 2018 Feb;53(1):123-130.
    PMID: 28940417 DOI: 10.1111/jre.12496
    BACKGROUND AND OBJECTIVE: The aim of the present study was to compare clinical periodontal parameters and to assess the release of C-telopeptides pyridinoline cross-links (ICTP) and C-terminal crosslinked telopeptide (CTX) from gingival collagen of naswar (NW) and non-naswar (control) dippers.

    MATERIAL AND METHODS: Eighty-seven individuals (42 individuals consuming NW and 45 controls) were included. Clinical (plaque index, bleeding on probing, probing depth and clinical attachment loss) and radiographic (marginal bone loss) periodontal parameters were compared among NW and control groups. Gingival specimens were taken from subjects in NW and control groups, assessed for ICTP and CTX levels (using ELISA) and analyzed using micro-Raman spectroscopy. The significance of differences in periodontal parameters between the groups was determined using Kruskal-Wallis and Mann-Whitney U tests. The percent loss of dry mass over exposure time and the rate of release of ICTP and CTX from all groups were compared using the paired t-test to examine the effects of exposure time.

    RESULTS: Clinical and radiographic periodontal parameters were significantly higher in the NW group than the control group (P spectrum, the strongest and sharpest band occurred at 1260 cm-1 amongst NW users. A Raman band at Amide I was observed with slight shifts in wave numbers. The rate of ICTP and CTX release was significantly higher in subjects from the NW group compared with those from the control group (P 

    Matched MeSH terms: Spectrum Analysis, Raman
  11. Fulltext Co-Blend Application Mode of Bulk Fill Composite Resin
    Al-Nabulsi M, Daud A, Yiu C, Omar H, Sauro S, Fawzy A, et al.
    Materials (Basel), 2019 Aug 07;12(16).
    PMID: 31394743 DOI: 10.3390/ma12162504
    Objective: To evaluate the effect of a new application method of bulk-fill flowable composite resin material on bond-strength, nanoleakage, and mechanical properties of dentine bonding agents.

    MATERIALS AND METHODS: Sound extracted human molars were randomly divided into: manufacturer's instructions (MI), manual blend 2 mm (MB2), and manual blend 4 mm (MB4). Occlusal enamel was removed and flattened, dentin surfaces were bonded by Prime & Bond universal (Dentsply and Optibond FL, Kerr). For the MI group, adhesives were applied following the manufacturer's instructions then light-cured. For MB groups, SDR flow+ bulk-fill flowable composite resin was applied in 2- or 4-mm increment then manually rubbed by a micro brush for 15 s with uncured dentine bonding agents and the mixture was light-cured. Composite buildup was fabricated incrementally using Ceram.X One, Dentsply nanohybrid composite resin restorative material. After 24-h water storage, the teeth were sectioned to obtain beams of about 0.8 mm2 for 24-h and thermocycled micro-tensile bond strength at 0.5 mm/min crosshead speed. Degree of conversion was evaluated with micro-Raman spectroscopy. Contraction gaps at 24 h after polymerization were evaluated and atomic force microscopy (AFM) nano-indentation processes were undertaken for measuring the hardness across the interface. Depth of resin penetration was studied using a scanning electron microscope (SEM). Bond strength data was expressed using two-way ANOVA followed by Tukey's test. Nanoindentation hardness was separately analyzed using one-way ANOVA.

    RESULTS: Factors "storage F = 6.3" and "application F = 30.11" significantly affected the bond strength to dentine. For Optibond FL, no significant difference in nanoleakage was found in MI/MB4 groups between baseline and aged specimens; significant difference in nanoleakage score was observed in MB2 groups. Confocal microscopy analysis showed MB2 Optibond FL and Prime & Bond universal specimens diffusing within the dentine. Contraction gap was significantly reduced in MB2 specimens in both adhesive systems. Degree of conversion (DC) of the MB2 specimens were numerically more compared to MS1 in both adhesive systems.

    CONCLUSION: Present study suggests that the new co-blend technique might have a positive effect on bond strengths of etch-and-rinse adhesives to dentine.

    Matched MeSH terms: Spectrum Analysis, Raman
  12. Colloidal surface-enhanced Raman spectroscopic study of grouper epidermal mucus using acidified sodium sulphate as the aggregating agent
    Leong N, Yaacob MH, Md Zain AR, Tengku Abdul Aziz TH, Christianus A, Chong CM, et al.
    Spectrochim Acta A Mol Biomol Spectrosc, 2024 Apr 15;311:123974.
    PMID: 38377639 DOI: 10.1016/j.saa.2024.123974
    Fish epidermal mucus is an important reservoir of antipathogenic compounds which serves as the first line of the immune defence. Despite its significant role in the physiology and health of fish, detailed profiling of fish epidermal mucus has yet to be explored. Therefore, this study investigates a label-free colloidal surface-enhanced Raman spectroscopic (SERS) method for profiling grouper mucus. Gold nanoparticles were first synthesised using the standard citrate reduction and characterised using ultraviolet-visible spectroscopy, transmission electron microscopy and dynamic light scattering. The influence of acidified sodium sulphate (Na2SO4) at pH 3 as the aggregating agent on the enhancement of the SERS spectrum of different analyte samples including rhodamine 6G (R6G) dye, lysozyme solution and hybrid grouper (Epinephelus fuscoguttatus × Epinephelus lanceolatus) mucus was observed. Based on the results, an optimal Na2SO4 concentration of 1 M was recorded to achieve the highest enhancement of the SERS signal for R6G and grouper mucus, while the optimal concentration for lysozyme was 0.1 M. The results indicated a higher degree of aggregation induced by lysozyme than R6G and grouper mucus. A few overlapping peaks of the SERS spectra of lysozyme and grouper mucus made it possible to confirm the presence of lysozyme as potential biomarkers.
    Matched MeSH terms: Spectrum Analysis, Raman/methods
  13. Fulltext Comparative Study of The Yield and Physicochemical Properties of Collagen from Sea Cucumber (Holothuria scabra), Obtained through Dialysis and the Ultrafiltration Membrane
    Saallah S, Roslan J, Julius FS, Saallah S, Mohamad Razali UH, Pindi W, et al.
    Molecules, 2021 Apr 28;26(9).
    PMID: 33924820 DOI: 10.3390/molecules26092564
    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.
    Matched MeSH terms: Spectrum Analysis
  14. Fulltext Complex Chemical Data Classification and Discrimination Using Locality Preserving Partial Least Squares Discriminant Analysis
    Aminu M, Ahmad NA
    ACS Omega, 2020 Oct 20;5(41):26601-26610.
    PMID: 33110988 DOI: 10.1021/acsomega.0c03362
    Partial least squares discriminant analysis (PLS-DA) is a well-known technique for feature extraction and discriminant analysis in chemometrics. Despite its popularity, it has been observed that PLS-DA does not automatically lead to extraction of relevant features. Feature learning and extraction depends on how well the discriminant subspace is captured. In this paper, discriminant subspace learning of chemical data is discussed from the perspective of PLS-DA and a recent extension of PLS-DA, which is known as the locality preserving partial least squares discriminant analysis (LPPLS-DA). The objective is twofold: (a) to introduce the LPPLS-DA algorithm to the chemometrics community and (b) to demonstrate the superior discrimination capabilities of LPPLS-DA and how it can be a powerful alternative to PLS-DA. Four chemical data sets are used: three spectroscopic data sets and one that contains compositional data. Comparative performances are measured based on discrimination and classification of these data sets. To compare the classification performances, the data samples are projected onto the PLS-DA and LPPLS-DA subspaces, and classification of the projected samples into one of the different groups (classes) is done using the nearest-neighbor classifier. We also compare the two techniques in data visualization (discrimination) task. The ability of LPPLS-DA to group samples from the same class while at the same time maximizing the between-class separation is clearly shown in our results. In comparison with PLS-DA, separation of data in the projected LPPLS-DA subspace is more well defined.
    Matched MeSH terms: Spectrum Analysis
  15. Conolodinines A-D, Aspidosperma- Aspidosperma Bisindole Alkaloids with Antiproliferative Activity from Tabernaemontana corymbosa
    Sim DS, Navanesan S, Sim KS, Gurusamy S, Lim SH, Low YY, et al.
    J Nat Prod, 2019 04 26;82(4):850-858.
    PMID: 30869890 DOI: 10.1021/acs.jnatprod.8b00919
    Examination of the EtOH extract of the leaves of the Malayan Tabernaemontana corymbosa resulted in the isolation of four new (1-4) and two known bisindole alkaloids (5, 6) of the Aspidosperma- Aspidosperma type. The structures of these alkaloids were determined based on analysis of the spectroscopic data (NMR and HRESIMS). X-ray diffraction analyses of the related bisindole alkaloids conophylline (5) and conophyllinine (6) established the absolute configurations. Treatment of the bisindole alkaloid conophylline (5) with benzeneselenic anhydride gave, in addition to the known bisindole polyervinine (7) previously isolated from another Malayan Tabernaemontana, another bisindole product, 8, an isolable tautomer of 7. X-ray diffraction analyses yielded the absolute configurations of both bisindoles and in addition showed that polyervinine (7) exists primarily as the neutral dione structure. The bisindoles (1-8) and the related conophylline-type bisindoles (9-13) showed pronounced in vitro growth inhibitory activity against an array of human cancer cell lines, including KB, vincristine-resistant KB, PC-3, LNCaP, MCF7, MDA-MB-231, A549, HT-29, and HCT 116 cells, with IC50 values for the active compounds in the 0.01-5 μM range.
    Matched MeSH terms: Spectrum Analysis/methods
  16. Constituents of the Edible Leaves of Melicope pteleifolia with Potential Analgesic Activity
    Lee BW, Park JG, Ha TKQ, Pham HTT, An JP, Noh JR, et al.
    J Nat Prod, 2019 08 23;82(8):2201-2210.
    PMID: 31393125 DOI: 10.1021/acs.jnatprod.9b00224
    Melicope pteleifolia has long been consumed as a popular vegetable and tea in Southeast Asian countries, including Malaysia and southern mainland China, and is effective in the treatment of colds and inflammation. In the search for active metabolites that can explain its traditional use as an antipyretic, six new phloroacetophenone derivatives (3-8) along with seven known compounds (1, 2, and 9-13) were isolated from the leaves of M. pteleifolia. Their chemical structures were confirmed by extensive spectroscopic analysis including NMR, IR, ECD, and HRMS. All compounds isolated from the leaves of M. pteleifolia (1-13) have a phloroacetophenone skeleton. Notably, the new compound 8 contains an additional cyclobutane moiety in its structure. The bioactivities of the isolated compounds were evaluated, and compounds 1, 6, and 7 inhibited tumor necrosis factor-α-induced prostaglandin E2. Moreover, the major constituent, 3,5-di-C-β-d-glucopyranosyl phloroacetophenone (1), was found to be responsible for the antipyretic activity of M. pteleifolia based on in vivo experiments.
    Matched MeSH terms: Spectrum Analysis/methods
  17. Coordination of Ce(III) and Nd(III) with pentaethylene glycol in the presence of picrate anion: spectroscopic and X-ray structural studies
    Kusrini E, Saleh MI, Lecomte C
    Spectrochim Acta A Mol Biomol Spectrosc, 2009 Sep 15;74(1):120-6.
    PMID: 19560960 DOI: 10.1016/j.saa.2009.05.024
    (1)H NMR evidence for direct coordination between the Ln(III) ion and the oxygen atoms of the pentaethylene glycol (EO5) ligand and the picrate anion (Pic) in [Ln(Pic)(2)(EO5)][Pic] {Ln=Ce and Nd} complexes are confirmed by single X-ray diffraction. No dissociation of Ln-O bonds in dimethyl sulfoxide-d solution was observed in NMR studies conducted at different temperatures ranging 25-100 degrees C. The Ln(III) ion was chelated to nine oxygen atoms from the EO5 ligand in a hexadentate manner and the two Pic anions in each bidentate and monodentate modes. Both compounds are isostructural and crystallized in monoclinic with space group P2(1)/c. Coordination environment around the Ce1 and Nd1 atoms can be described as tricapped trigonal prismatic and monocapped square antiprismatic geometries, respectively. The crystal packing of the complexes have stabilized by one dimensional (1D) chains along the [001] direction to form intermolecular O-Hcdots, three dots, centeredO and C-Hcdots, three dots, centeredO hydrogen bonding. The molar conductance of the complexes in DMSO solution indicated that both compounds are ionic. The complexes had a good thermal stability. Under the UV-excitation, these complexes exhibited the red-shift emission.
    Matched MeSH terms: Spectrum Analysis
  18. Fulltext Crystallization of Electrodeposited Germanium Thin Film on Silicon (100)
    Abidin MSZ, Matsumura R, Anisuzzaman M, Park JH, Muta S, Mahmood MR, et al.
    Materials (Basel), 2013 Nov 06;6(11):5047-5057.
    PMID: 28788375 DOI: 10.3390/ma6115047
    We report the crystallization of electrodeposited germanium (Ge) thin films on n-silicon (Si) (100) by rapid melting process. The electrodeposition was carried out in germanium (IV) chloride: propylene glycol (GeCl₄:C₃H₈O₂) electrolyte with constant current of 50 mA for 30 min. The measured Raman spectra and electron backscattering diffraction (EBSD) images show that the as-deposited Ge thin film was amorphous. The crystallization of deposited Ge was achieved by rapid thermal annealing (RTA) at 980 °C for 1 s. The EBSD images confirm that the orientations of the annealed Ge are similar to that of the Si substrate. The highly intense peak of Raman spectra at 300 cm(-1) corresponding to Ge-Ge vibration mode was observed, indicating good crystal quality of Ge. An additional sub peak near to 390 cm(-1) corresponding to the Si-Ge vibration mode was also observed, indicating the Ge-Si mixing at Ge/Si interface. Auger electron spectroscopy (AES) reveals that the intermixing depth was around 60 nm. The calculated Si fraction from Raman spectra was found to be in good agreement with the value estimated from Ge-Si equilibrium phase diagram. The proposed technique is expected to be an effective way to crystallize Ge films for various device applications as well as to create strain at the Ge-Si interface for enhancement of mobility.
    Matched MeSH terms: Spectrum Analysis
  19. Crystallographic, vibrational and DFT studies of 1-(2-hydroxy-4,5-dimethylphenyl)ethanone
    Chidan Kumar CS, Parlak C, Fun HK, Tursun M, Bilge M, Chandraju S, et al.
    Spectrochim Acta A Mol Biomol Spectrosc, 2015 Oct 5;149:762-70.
    PMID: 25989614 DOI: 10.1016/j.saa.2015.05.012
    Molecular structure and properties of 1-(2-hydroxy-4,5-dimethylphenyl)ethanone were experimentally investigated by X-ray diffraction technique and vibrational spectroscopy. Experimental results on the molecular structure of the reported compound were supported with computational studies using the density functional theory (DFT), with the Becke-3-Lee-Yang-Parr (B3LYP) functional and the 6-311+G(3df,p) basis set. Potential energy distribution (PED) and potential energy surface (PES) analyses were performed to identify characteristic frequencies and reliable conformational analysis correspondingly. The compound crystallizes in monoclinic space group C2/c with the CO up-OH down conformation. There is a good agreement between the experimentally determined geometrical parameters and vibrational frequencies of the compound to those predicted theoretically.
    Matched MeSH terms: Spectrum Analysis
  20. Current analytical methods for porcine identification in meat and meat products
    Zia Q, Alawami M, Mokhtar NFK, Nhari RMHR, Hanish I
    Food Chem, 2020 Sep 15;324:126664.
    PMID: 32380410 DOI: 10.1016/j.foodchem.2020.126664
    Authentication of meat products is critical in the food industry. Meat adulteration may lead to religious apprehensions, financial gain and food-toxicities such as meat allergies. Thus, empirical validation of the quality and constituents of meat is paramount. Various analytical methods often based on protein or DNA measurements are utilized to identify meat species. Protein-based methods, including electrophoretic and immunological techniques, are at times unsuitable for discriminating closely related species. Most of these methods have been replaced by more accurate and sensitive detection methods, such as DNA-based techniques. Emerging technologies like DNA barcoding and mass spectrometry are still in their infancy when it comes to their utilization in meat detection. Gold nanobiosensors have shown some promise in this regard. However, its applicability in small scale industries is distant. This article comprehensively reviews the recent developments in the field of analytical methods used for porcine identification.
    Matched MeSH terms: Spectrum Analysis/methods
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