MyMedR

Displaying publications 1 - 20 of 45 in total

Abstract:

Sort:

Performance of platinum doping on spent alkaline battery-based catalyst for complete oxidation of o-xylene

Park YK, Jung SC, Jung HY, Foong SY, Lam SS, Kim SC

Environ Sci Pollut Res Int, 2021 May;28(19):24552-24557.
PMID: 32533488 DOI: 10.1007/s11356-020-09575-6

Oxidation of o-xylene was performed using alkaline battery-based catalyst doped with platinum to investigate the properties and activities. O-xylene was selected as the model of volatile organic compound (VOC) in this work. Physicochemical properties of the selected catalysts were characterized by FE/TEM (field emission transmission electron microscopy), BET (Brunauer-Emmett-Teller) analysis, XRD (X-ray powder diffraction), SEM/EDX (scanning electron microscopy/energy dispersive X-ray spectroscopy), and H2-TPR (hydrogen temperature programmed reduction). Major elements of the spent alkaline battery-based catalyst treated with sulfuric acid solution [SAB (400) catalyst] were manganese, zinc, iron, oxygen, carbon, chlorine, aluminum, sodium, silicon, and potassium. Increasing the doping amount of platinum on SAB (400) catalyst from 0.1 to 1 wt% increased particle size of platinum and lowered the temperature of TPR (TTP) for SAB (400) catalyst. Better redox properties were achieved with an increase in the o-xylene conversion according to the doping amount of platinum. When GHSV (gas hourly space velocity) was 40,000 h-1, o-xylene was oxidized completely over SAB (400) catalyst and 1.0 wt% Pt/SAB(400) catalyst at temperatures of 400 °C and 280 °C, respectively.

Matched MeSH terms: Platinum*
Fulltext Optical and Thermal Properties of Laser-Ablated Platinum Nanoparticles Graphene Oxide Composite

Sadrolhosseini AR, Habibiasr M, Shafie S, Solaimani H, Lim HN

Int J Mol Sci, 2019 Dec 06;20(24).
PMID: 31817593 DOI: 10.3390/ijms20246153

Platinum nanoparticles were synthesized in graphene oxide aqueous solution using a laser ablation technique to investigate the effect of optical linear, nonlinear and thermal properties of platinum-graphene oxide nanocomposite solution. The samples were prepared with different ablation times. The platinum nanoparticles that formed a spherical shape on the surface of graphene oxide solution were authenticated using UV-visible spectrum and transmission electron microscopy patterns. The particle size decreased with increasing ablation time, and the concentration and volume fraction of samples were increased. To obtain the optical linear, nonlinear and thermal properties of platinum-graphene oxide nanocomposite solution, UV-visible spectroscopy, Z-scan, thermal lens and photoacoustic techniques were used. Consequently, the linear and nonlinear refractive indices increased with an increase in the volume fraction of platinum nanoparticles. It was observed from the spatial self-phase modulation patterns that, the optical nonlinear property of the graphene oxide was enhanced in the presence of platinum nanoparticles, and the nonlinearity increased with an increase in the volume fraction of platinum nanoparticles inside the graphene oxide solution. The thermal diffusivity and thermal effusivity of platinum nanoparticles graphene oxide were measured using a thermal lens and photoacoustic methods, respectively. The thermal diffusivity and thermal effusivity of samples were in the range of 0.0341 × 10-5 m2/s to 0.1223 × 10-5 m2/s and 0.163 W s1/2 cm-2 K-1 to 0.3192 W s1/2 cm-2 K-1, respectively. Consequently, the platinum enhanced the optical and thermal properties of graphene oxide.

Matched MeSH terms: Platinum/chemistry*
Pembrolizumab monotherapy versus chemotherapy in platinum-pretreated, recurrent or metastatic nasopharyngeal cancer (KEYNOTE-122): an open-label, randomized, phase III trial

Chan ATC, Lee VHF, Hong RL, Ahn MJ, Chong WQ, Kim SB, et al.

Ann Oncol, 2023 Mar;34(3):251-261.
PMID: 36535566 DOI: 10.1016/j.annonc.2022.12.007

BACKGROUND: Pembrolizumab previously demonstrated robust antitumor activity and manageable safety in a phase Ib study of patients with heavily pretreated, programmed death ligand 1 (PD-L1)-positive, recurrent or metastatic nasopharyngeal carcinoma (NPC). The phase III KEYNOTE-122 study was conducted to further evaluate pembrolizumab versus chemotherapy in patients with platinum-pretreated, recurrent and/or metastatic NPC. Final analysis results are presented.
PATIENTS AND METHODS: KEYNOTE-122 was an open-label, randomized study conducted at 29 sites, globally. Participants with platinum-pretreated recurrent and/or metastatic NPC were randomly assigned (1 : 1) to pembrolizumab or chemotherapy with capecitabine, gemcitabine, or docetaxel. Randomization was stratified by liver metastasis (present versus absent). The primary endpoint was overall survival (OS), analyzed in the intention-to-treat population using the stratified log-rank test (superiority threshold, one-sided P = 0.0187). Safety was assessed in the as-treated population.
RESULTS: Between 5 May 2016 and 28 May 2018, 233 participants were randomly assigned to treatment (pembrolizumab, n = 117; chemotherapy, n = 116); Most participants (86.7%) received study treatment in the second-line or later setting. Median time from randomization to data cut-off (30 November 2020) was 45.1 months (interquartile range, 39.0-48.8 months). Median OS was 17.2 months [95% confidence interval (CI) 11.7-22.9 months] with pembrolizumab and 15.3 months (95% CI 10.9-18.1 months) with chemotherapy [hazard ratio, 0.90 (95% CI 0.67-1.19; P = 0.2262)]. Grade 3-5 treatment-related adverse events occurred in 12 of 116 participants (10.3%) with pembrolizumab and 49 of 112 participants (43.8%) with chemotherapy. Three treatment-related deaths occurred: 1 participant (0.9%) with pembrolizumab (pneumonitis) and 2 (1.8%) with chemotherapy (pneumonia, intracranial hemorrhage).
CONCLUSION: Pembrolizumab did not significantly improve OS compared with chemotherapy in participants with platinum-pretreated recurrent and/or metastatic NPC but did have manageable safety and a lower incidence of treatment-related adverse events.

Matched MeSH terms: Platinum*
Fulltext Demonstration of chemistry at a point through restructuring and catalytic activation at anchored nanoparticles

Neagu D, Papaioannou EI, Ramli WKW, Miller DN, Murdoch BJ, Ménard H, et al.

Nat Commun, 2017 11 30;8(1):1855.
PMID: 29187751 DOI: 10.1038/s41467-017-01880-y

Metal nanoparticles prepared by exsolution at the surface of perovskite oxides have been recently shown to enable new dimensions in catalysis and energy conversion and storage technologies owing to their socketed, well-anchored structure. Here we show that contrary to general belief, exsolved particles do not necessarily re-dissolve back into the underlying perovskite upon oxidation. Instead, they may remain pinned to their initial locations, allowing one to subject them to further chemical transformations to alter their composition, structure and functionality dramatically, while preserving their initial spatial arrangement. We refer to this concept as chemistry at a point and illustrate it by tracking individual nanoparticles throughout various chemical transformations. We demonstrate its remarkable practical utility by preparing a nanostructured earth abundant metal catalyst which rivals platinum on a weight basis over hundreds of hours of operation. Our concept enables the design of compositionally diverse confined oxide particles with superior stability and catalytic reactivity.

Matched MeSH terms: Platinum
Perbandingan hasil pengoksidaan elektrokimia etanol dalam larutan alkali yang menggunakan elektrod platinum-polivinilklorida (Pt-PVC) dan kepingan logam Pt

Riyanto, Jumat Salimon, Mohamed Rozali Othman

Sains Malaysiana, 2007;36:175-181.

Elektrod platinum-polivinilklorida (Pt-PVC) untuk pengoksidaan elektrokimia etanol dalam larutan alkali telah direkabentuk. Elektrod Pt-PVC dibina dengan mencampurkan serbuk-serbuk logam platinum dengan PVC (95:5 w/w), diaduk untuk mendapatkan campuran yang homogen, ditambahkan dengan tetrahidrofuran (THF) untuk melarutkan PVC, dikeringkan, dimasukkan ke dalam acuan berdiameter 1 cm dan ditekan pada tekanan kira-kira 10 tan/cm2. Kajian elektrokimia dilakukan menggunakan voltammetri kitaran (CV) dan kronokoulometri (CC). CV untuk etanol yang menggunakan elektrod-elektrod kepingan logam Pt dan Pt-PVC masing-masing memberikan ketumpatan arus 0.25 mA/cm2 dan 85 mA/cm2 untuk puncak penjerapan hidroksida. Ini menunjukkan bahawa elektrod Pt-PVC mempunyai nilai konduktiviti dan perilaku elektrokimia yang lebih baik untuk pengoksidaan etanol dalam KOH berbanding elektrod kepingan logam Pt. Hasil kajian mendapati bahawa terdapat peningkatan peratus hasil elektrolisis dari 3.64% kepada 23.64% asid asetik apabila elektrod Pt-PVC digunakan untuk pengoksidaan elektrokimia 0.25 M etanol dalam larutan elektrolit 1.0 M KOH menggantikan elektrod kepingan logam Pt.

Matched MeSH terms: Platinum
One-step anodization of aluminum at room temperature

Araoyinbo AO, Ahmad Fauzi M, Sreekantan S, Azizan Aziz

Sains Malaysiana, 2009;38.

The formation of nano pores on aluminum at 30oC- 38oC, employing a one step anodization technique which does not require removing the oxide layer formed is presented. A 20% phosphoric acid electrolyte (concentration higher than the normal anodization concentration of 5 to 10%) at a cell potential of 60 volts was used. A platinum electrode was used as the cathode electrode while the aluminum substrate as the anode electrode. A dc powered electrochemical cell to provide the required amount of current density (without the use of temperature controlled water bath) suitable or necessary for pore formation at room temperature was employed. The results obtained show that pore formation at room temperature is achievable and the pore diameter ranged between 80-120 nm.

Matched MeSH terms: Platinum
Determination of HOMO and LUMO of [6,6]-Phenyl C61-butyric Acid 3-ethylthiophene ester and poly (3-octyl-thiophene-2, 5-diyl) through voltametry characterization

Ashkan Shafiee, Muhamad Mat Salleh, Muhammad Yahaya

Sains Malaysiana, 2011;40.

HOMO and LUMO of organic compounds are basic parameters for the design and fabrication of an organic solar cell. This paper presents a technique to obtain HOMO and LUMO of an n-type polymer of [6,6]-phenyl C61-butyric acid 3-ethylthiophene ester (PCBE) and a p-type polymer of poly (3-octyl-thiophene-2, 5-diyl) (P3OT). The energy of band gap for each material has been calculated using optical absorption spectrum. Cyclic Voltammetry was used to estimate the oxidation potential and energy band diagram consequently. The experiments were carried out in a three-electrode cell consisting of a platinum working electrode, a platinum counter electrode and a SCE reference electrode. P3OT showed energy band gap equal to 1.83 eV with HOMO and LUMO equal to 5.59 eV and 3.76 eV, respectively. PCBE showed energy band gap equal to 1.96 eV with HOMO and LUMO equal to 5.87 eV and 3.91 eV, respectively. Based on energy band diagram that was constructed from this experimental result, the couple materials may be successfully used to fabricate the feasible organic solar cells.

Matched MeSH terms: Platinum
Transport properties and sensing responses of platinum nanoparticles/graphen structure fabricated by thermal annealing process

Mohammad Sarwan Mohd Sanif, Amgad Ahmed Ali, Lee MW, Lee HW, Chia Sheng DB, Abdul Manaf Hashim

Sains Malaysiana, 2017;46:1119-1924.

The effects of the annealing temperatures and thicknesses on the shapes, sizes and arrangement of platinum (Pt) nanoparticles (NPs) on graphene and their sensing performance for hydrogen (H2) detection were investigated. It shows strong dependency of the annealing temperatures and thicknesses on the properties of NPs. It was found that the proposed technique is able to form the NPs with good size controllability and uniformity even for thick deposited layer, thus eliminating the requirement of very thin layer of below 5 nm for the direct NP synthesis by evaporation or sputtering. The transport properties of Pt NPs/graphene structure and its sensing performance on H2 at room temperature under various H2 concentration were evaluated. The results showed an acceptable sensing response, indicating an innovative approach to fabricate Pt NPs embedded graphene for gas sensing application.

Matched MeSH terms: Platinum
Determining the type of bond between diatomic cluster of platinum and hydrogen: quantum mechanical approach

Anas M, Gopir G, Miswan M

Sains Malaysiana, 2018;47:999-1003.

Type of bond is vital to understand the mechanism of interaction between corresponds atoms. We used three kinds of method
to determine the type of bond between diatomic cluster of platinum and hydrogen: types of element, electronegativity
and electron distribution. In this work, we found that the results from these three methods are not unanimously agreed
with each other for bond type forming in platinum-hydrogen diatomic cluster. Thus, we conclude that the type of bond
is hybrid of both: mainly covalent and slightly ionic.

Matched MeSH terms: Platinum
Synthesis, Characterization and DNA-Binding Studies of Hydroxyl Functionalized Platinum(II) Salphen Complexes

Mohd Sukri SA, Heng LY, Abd Karim NH

J Fluoresc, 2017 May;27(3):1009-1023.
PMID: 28224358 DOI: 10.1007/s10895-017-2035-0

The platinum(II) salphen complex N,N'-Bis-4-(hydroxysalicylidene)-phenylenediamine-platinum(II); (1) and its two derivatives containing hydroxyl functionalized side chains N,N'-bis-[4-[[1-(2-hydroxyethoxy)] salicylidene] phenylenediamine-platinum(II); (2) and N,N'-bis-[4-[[1-(3-hydroxypropoxy)] salicylidene] phenylenediamine-platinum(II); (3) were synthesized and characterized. The structures of the complexes were confirmed by 1H and 13C NMR spectroscopy, FTIR, ESI-MS and CHN elemental analyses. The effects of the hydroxyl substituent on the spectral properties and the DNA binding behaviors of the Pt(II) complexes were explored. The binding mode and interactions of these complexes with duplex DNA (calf thymus DNA and porcine DNA) and also single-stranded DNA were studied by UV-Vis and emission DNA titration. The complexes interact with DNA by intercalation binding mode with the binding constants in the order of magnitude (Kb = 104 M-1, CT-DNA) and (Kb = 105 M-1, porcine DNA). The intercalation of the complex in the DNA structure was proposed to happen by π-π stacking due to its square-planar geometry and aromatic rings structure. The phosphorescence emission spectral characteristics of Pt(II) complexes when interacted with DNA have been studied. Also, the application of the chosen hydroxypropoxy side chains complex (3) as an optical DNA biosensor, specifically for porcine DNA was investigated. These findings will be valuable for the potential use of the platinum(II) salphen complex as an optical DNA biosensor for the detection of porcine DNA in food products.

Matched MeSH terms: Platinum/chemistry*
Fulltext Influence of dose on particle size and optical properties of colloidal platinum nanoparticles

Gharibshahi E, Saion E

Int J Mol Sci, 2012;13(11):14723-41.
PMID: 23203091 DOI: 10.3390/ijms131114723

Attempts to produce colloidal platinum nanoparticles by using steady absorption spectra with various chemical-based reduction methods often resulted in the fast disappearance of the absorption maxima leaving reduced platinum nanoparticles with little information on their optical properties. We synthesized colloidal platinum nanoparticles in an aqueous solution of polyvinyl pyrrolidone by gamma radiolytic reduction method, which produced steady absorption spectra of fully reduced and highly pure platinum nanoparticles free from by-product impurities or reducing agent contamination. The average particle size was found to be in the range of 3.4–5.3 nm and decreased with increasing dose due to the domination of nucleation over ion association in the formation of metal nanoparticles by the gamma radiolytic reduction method. The platinum nanoparticles exhibit optical absorption spectra with two absorption peaks centered at about 216 and 264 nm and the peaks blue shifted to lower wavelengths with decreasing particle size. The absorption spectra of platinum nanoparticles were also calculated using quantum mechanical treatment and coincidently a good agreement was obtained between the calculated and measured absorption peaks at various particle sizes. This indicates that the 216 and 264-nm absorption peaks of platinum nanoparticles conceivably originated from the intra-band transitions of conduction electrons of (n = 5, l = 2) and (n = 6, l = 0) energy states respectively to higher energy states. The absorption energies, i.e., conduction band energies of platinum nanoparticles derived from the absorption peaks increased with increasing dose and decreased with increasing particle size.

Matched MeSH terms: Platinum/chemistry*
Combining Copper and Zinc into a Biosensor for Anti-Chemoresistance and Achieving Osteosarcoma Therapeutic Efficacy

Lim YY, Zaidi AMA, Miskon A

Molecules, 2023 Mar 24;28(7).
PMID: 37049685 DOI: 10.3390/molecules28072920

Due to its built-up chemoresistance after prolonged usage, the demand for replacing platinum in metal-based drugs (MBD) is rising. The first MBD approved by the FDA for cancer therapy was cisplatin in 1978. Even after nearly four and a half decades of trials, there has been no significant improvement in osteosarcoma (OS) therapy. In fact, many MBD have been developed, but the chemoresistance problem raised by platinum remains unresolved. This motivates us to elucidate the possibilities of the copper and zinc (CuZn) combination to replace platinum in MBD. Thus, the anti-chemoresistance properties of CuZn and their physiological functions for OS therapy are highlighted. Herein, we summarise their chelators, main organic solvents, and ligand functions in their structures that are involved in anti-chemoresistance properties. Through this review, it is rational to discuss their ligands' roles as biosensors in drug delivery systems. Hereafter, an in-depth understanding of their redox and photoactive function relationships is provided. The disadvantage is that the other functions of biosensors cannot be elaborated on here. As a result, this review is being developed, which is expected to intensify OS drugs with higher cure rates. Nonetheless, this advancement intends to solve the major chemoresistance obstacle towards clinical efficacy.

Matched MeSH terms: Platinum/pharmacology
A synergistic heterostructured ZnO/BaTiO3 loaded carbon photoanode in photocatalytic fuel cell for degradation of Reactive Red 120 and electricity generation

Ong YP, Ho LN, Ong SA, Banjuraizah J, Ibrahim AH, Lee SL, et al.

Chemosphere, 2019 Mar;219:277-285.
PMID: 30543963 DOI: 10.1016/j.chemosphere.2018.12.004

Photocatalytic fuel cell (PFC) is considered as a sustainable green technology which could degrade organic pollutant and generate electricity simultaneously. A synergistic double-sided ZnO/BaTiO3 loaded carbon plate heterojunction photoanode was fabricated in different ratios by using simple ultrasonication and mixed-annealed method. The double-sided design of photoanode allowed the lights irradiated at both sides of the photoanode. The ferroelectricity fabricated photoanode was applied in a membraneless PFC with platinum-loaded carbon as the cathode. Results revealed that the photoanode with 1:1 ratio of BaTiO3 and ZnO exhibited a superior photocatalytic activity among all the photoanodes prepared in this study. The heterojunction of this photoanode was able to achieve up to a removal efficiency of 93.67% with a maximum power density of 0.5284 μW cm-2 in 10 mg L-1 of Reactive Red 120 (RR120) without any supporting electrolyte. This photoanode was able to maintain at high performance after recycling 3 times. Overloading of ZnO above 50% on BaTiO3 could lead to deterioration of the performance of PFC due to the charge defects and light trapping ability. The interactions, interesting polarizations of the photocatalysts and proposed mechanism of the n-n type heterojunction in the photoanode of ZnO/BaTiO3 was also discussed.

Matched MeSH terms: Platinum
Separation of geraniol from citronellol by selective oxidation of geraniol to geranial

Jalifah binti Latip, Daniel Chong Jun Weng, Siti Aishah binti Hasbullah, Harjono Sastrohamidjojo

Sains Malaysiana, 2015;44:1183-1188.

Rhodinol is a mixture of geraniol and citronellol. It is the second fraction in fractional distillation of commercially grown Cymbopogon nardus. The physical and chemical similarities of these two compounds made them inseparable. The individual use of each compound is of great importance. A selective oxidation (hydrogen peroxide activated by platinum black) of geraniol (in rhodinol) to geranial was done while remaining citronellol intact in order to separate the two compounds into different chemical functionality. A yield of 81% geranial achieved while minimizing citronellal formation from citronellol to 17%. Chemical separation using sodium hydrogen sulfite (NaHSO3) was done to separate the aldehydes from the unreacted citronellol. Purification using fractional distillation was done to obtain pure geraniol and remove minor fraction of citronellal.

Matched MeSH terms: Platinum
Fulltext Recovery of heavy metals from spent etching waste solution of printed circuit board (PCB) manufacturing

Ali, A.H.M., Sobri, S., Salmiaton, A., Faizah, M.Y.

Pertanika Journal of Science & Technology, 2013;21(2):375-386.
MyJurnal

The process of etching is the most crucial part of the work of manufacturing printed circuit boards (PCB). In the etching process by nitric acid, a spent etching waste solution of composition 250 g/L HNO3, 30-40 g/L Cu, 30-40 g/L Sn, 30-40 g/L Pb and 20-25 g/L Fe is produced. High metal concentrations in the spent etching waste solution make it a viable candidate for the recovery of metals. Recovery of metals from spent etching waste solution is a significant concern as the recent growth in production of printed circuit boards has generated a drastic increase of spent etching waste solution each year. This study concerns itself with the recovery of metals from spent etching waste. In this study a dilution was made in order to increase the pH of the solution as spent etching waste solution has high acidity, and the electrowinning method was performed to recover metals from the spent etching waste solution. Glassy carbon and platinum were used as cathode and anode in order to investigate the electrodeposition of metals and cyclic voltammetry investigation suggests that the deposition of metals on glassy carbon electrodes occurs at four different overpotentials mainly at -0.15 V, -0.35 V, -0.45 V and -0.75 V. Microscopy observation demonstrates that there is a deposition of metals by applying the potentials in a set of current-time transient study for a duration of 60 seconds and the metals recovered formed as aggregates.

Matched MeSH terms: Platinum
Synergistic strategies: histone deacetylase inhibitors and platinum-based drugs in cancer therapy

Shirbhate E, Singh V, Kore R, Koch B, Veerasamy R, Tiwari AK, et al.

Expert Rev Anticancer Ther, 2025 Feb;25(2):121-141.
PMID: 39873641 DOI: 10.1080/14737140.2025.2458156

INTRODUCTION: The synergistic combination of histone deacetylase inhibitors and platinum-based medicines represents a promising therapeutic strategy to efficacy and overcome drug resistance in cancer therapy, necessitating a comprehensive understanding on their molecular interactions and clinical potential.
AREAS COVERED: The objective of presented review is to investigate the molecular pathways of platinum medicines and HDAC inhibitors. A comprehensive literature review from 2011 to 2024 was conducted across multiple databases like MEDLINE, PubMed, Google Scholar, Science Direct, Scopus and official websites of ClinicalTrial.gov to explore publications on HDAC inhibitors, platinum drugs, and combination cancer therapies, revealing preliminary evidence of innovative treatment strategies involving HDAC inhibitors and platinum chemotherapeutics. Several new platinum (IV) complexes, with HDAC inhibitory moieties and better cytotoxicity profiles than conventional platinum drugs, are also reviewed here.
EXPERT OPINION: The above combination has great potential in cancer treatment, however managing toxicity, dosage regimens, and patient selection biomarkers are problematic. More selective HDAC inhibitors and innovative delivery techniques are potential areas for future research. An adaptation toward changing cancer therapeutic landscapes, highlights combining HDAC inhibitors with platinum-based medicines serves as a new concept for personalized medicine, however, a deeper research is still needed at this time.

Matched MeSH terms: Organoplatinum Compounds/administration & dosage; Organoplatinum Compounds/pharmacology; Platinum Compounds/administration & dosage; Platinum Compounds/pharmacology
Size-Controlled and Optical Properties of Platinum Nanoparticles by Gamma Radiolytic Synthesis

Gharibshahi E, Saion E, Ashraf A, Gharibshahi L

Appl Radiat Isot, 2017 Dec;130:211-217.
PMID: 29028581 DOI: 10.1016/j.apradiso.2017.09.012

Gamma radiolytic synthesis was used to produce size-controlled spherical platinum nanoparticles from an aqueous solution containing platinum tetraammine and polyvinyl pyrrolidone. The structural characterizations were performed using X-ray diffraction, and transmission electron microscopy. The transmission electron microscopy was used to determine the average particle diameter, which decreased from 4.4nm at 80kGy to 2.8nm at 120kGy. The UV-visible absorption spectrum was measured and found that platinum nanoparticles exhibit two steady absorption maxima in UV regions due to plasmonic excitation of conduction electrons, which blue shifted to lower wavelengths with a decrease in particle size. We consider the conduction electrons of platinum nanoparticles to follow Thomas-Fermi-Dirac-Weizsacker atomic model that they are not entirely free but weakly bounded to particles at lower-energy states {n = 5, l = 2 or 5d} and {n = 6, l = 0 or 6s}, which upon receiving UV photon energy the electrons make intra-band quantum excitations to higher-energy states allowed by the principles of quantum number that results the absorption maxima. We found an excellent agreement between the experimental and theoretical results, which suggest that the optical absorption of metal nanoparticles could be fundamentally described by a quantum mechanical interpretation, which could be more relevant to photo-catalysis and heterogeneous catalysis.

Matched MeSH terms: Platinum
Neuroendocrine carcinoma of the cervix: Review of classification and current developments in diagnosis and management

Kavitha Nagandla, Sharifah Sulaiha, Sivalingam Nalliah, Norfadzilah Mohd Yusof

International e-Journal of Science, Medicine & Education, 2017;11(1):2-11.
MyJurnal

Neuroendocrine carcinoma of the female
reproductive tract are a heterogeneous group of rare
neoplasms posing both diagnostic and therapeutic
challenges. The recent classification by WHO
includes neuroendocrine carcinomas (NECs) and
neuroendocrine tumours (NETs). NECs are the poorly
differentiated small cell carcinoma (SCNEC) and
large cell neuroendocrine carcinoma (LCNEC), while
well-differentiated NETs include typical carcinoids
(TC) and atypical carcinoids (AC). Majority of
these tumours have an aggressive clinical course and
published data is supportive of multi-modal therapeutic
strategies. Etoposide/platinum based chemotherapy is
commonly advocated. Histopathological categorisation
and diagnosis are paramount to guide therapy.
Well-differentiated carcinoid and atypical
carcinoid tumours should be managed similar to
gastroenteropancreatic neuroendocrine tumours.
This review discusses the current classification, clinicpathologic
characteristics and advances in the diagnostic
evaluation and the treatment options of neuroendocrine
carcinoma of the cervix.

Matched MeSH terms: Platinum
Theory and experiment of optical absorption of platinum nanoparticles synthesized by gamma radiation

Gharibshahi E, Saion E, Johnston RL, Ashraf A

Appl Radiat Isot, 2019 May;147:204-210.
PMID: 30953937 DOI: 10.1016/j.apradiso.2019.02.015

Platinum nanoparticles were synthesized using the gamma radiolytic technique in an aqueous solution containing Platinum tetraammine chloride in presence of poly vinyl pyrrolidone, isopropanol, tetrahydrofuran and deionized water. The gamma irradiation was carried out in a60Co gamma source chamber and the particle size was found to decrease from 4.88 to 3.14 nm on increasing the gamma radiation dose from 80 to 120 kGy. UV-visible absorption spectra were measured and revealed two steady absorption maxima at 216 and 264 nm in the UV region, which was blue shifted (i.e. toward lower wavelength) with decreasing particle size. By taking the conduction electrons of an isolated particle that are not entirely free, but instead bound to their respective quantum levels, the optical absorption of platinum nanoparticles can be calculated via intra-band quantum excitation for particle sizes similar to those measured experimentally. We found that the calculated absorption maxima of electronic excitations matched the measured absorption maxima well. This finding suggests that the optical absorption of metal nanoparticles commonly applied in nanoscience and nanotechnology can be described accurately by the quantum excitation of conduction electrons.

Matched MeSH terms: Platinum
Morphological study of synthesized RGO/ Pt nanocomposites via facile chemical reduction method

Mohamad Fahrul Radzi Hanifah, Juhana Jaafar, Madzlan Aziz, Mohd Hafiz Dzarfan Othman, Mukhlis A. Rahman, Ahmad Fauzi Ismail, et al.

Sains Malaysiana, 2017;46:629-635.

Reduced graphene oxide nanosheet (RGO)/Pt nanocomposite have been successfully prepared through a facile chemical reduction method. The reduction of Pt precursor was carried out using sodium borohydride as the efficient chemical reductant. The morphology of RGO/Pt nanocomposite was investigated using high resolution transmission electron microscopy (HRTEM) and field emission scanning electron microscopy (FESEM). HRTEM analysis showed that platinum nanoparticles were homogenously distributed onto the surface of RGO. The electrochemical study proved that Pt nanoparticles were successfully incorporated onto RGO. Therefore, it can be concluded that the proposed method could provide well-dispersed of Pt nanoparticles onto RGO to form RGO/ Pt nanocomposite.

Matched MeSH terms: Platinum

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links