Nicotinamide adenine dinucleotide immobilized tungsten trioxide nanoparticles for simultaneous sensing of norepinephrine, melatonin and nicotine.

Herein, we report the anionic surfactant, ethylene diamine tetraacetic acid (EDTA), mediated synthesis of WO3 nanoparticles and its subsequent modification through gamma irradiation (GI) and electrochemical immobilization with nicotinamide adenine dinucleotide (NAD). Glassy carbon electrode (GCE) modified with GI-WO3 NPs and the enzyme NAD exhibited strong electro-oxidation of three important biomolecules such as norepinephrine (NEP), melatonin (MEL) and nicotine (NIC) in 0.1 M phosphate buffer saline (PBS) at physiological pH of 7. Square wave voltammetry (SWV) studies exhibited three well-defined peaks at potentials of 120, 570 and 840 mV, corresponding to the oxidation of NEP, MEL and NIC respectively, indicating that simultaneous determination of these compounds is feasible at the NAD/GI EDTA-WO3/GCE. The proposed sensor displayed a wide linear range of 0.010-1000 µM with the lowest detection limit of 1.4 nM for NEP, 2.6 nM for MEL and 1.7 nM for NIC respectively. Furthermore, the modified electrode was successfully applied to detect NEP, MEL and NIC in pharmaceutical and cigarette samples with excellent selectivity and reproducibility.

Electrochemical determination of purine and pyrimidine bases using copper doped cerium oxide nanoparticles.

Deoxyribonucleic acid (DNA), a primary unit of heredity in all types of organisms, consists of purine and pyrimidine bases in such a way that the amount of guanine (GU) is equal to cytosine (CY) and the amount of adenine (AD) is equal to thymine (TY). Any abnormalities in the concentration of these four bases will have significant influence on disease diagnosis, crime detection and biocomputing applications of DNA. Hence, identification and quantification of either individual or group of these DNA bases are important for diagnosis of certain diagnosis and genetic disorders. In the present work, we report the fabrication of an efficient electrochemical sensor for simultaneous determination of purine (GU, AD) and pyrimidine (CY, TY) bases using Cu doped CeO2 nanoparticles modified glassy carbon electrode (Cu-CeO2/GCE). The direct electrocatalytic activities of DNA bases have been studied using voltammetric techniques in phosphate buffer solution (PBS, pH 7.0) without any enzyme or mediator. 3 wt% Cu doped CeO2 modified GCE showed two well defined anodic peaks each towards the oxidation of purine and pyrimidine bases with significant peak to peak potential separation of 312 mV (AD-GU) and 200 mV (TY-CY) which were large enough for the selective and simultaneous determination of these bases in their mixture. Under optimum conditions, calibration plots for the simultaneous detection of the purine and pyrimidine bases were linear in the concentration range of 0.1-500 µM for AD, 1-650 µM for GU, 1-300 µM for TY and 1-250 for CY with the lowest detection limit values of 0.021, 0.031, 0.024, and 0.038 µM respectively. Additionally, the developed sensor exhibited good repeatability, reproducibility, sufficient stability and good anti-interference ability and was successfully applied for simultaneous detection of AD, GU, TY and CY in denatured DNA sample with satisfactory results.

Clinical profile and outcomes of patients with Stage IV adenocarcinoma of lung: A tertiary cancer center experience.

BACKGROUND: There is limited Indian data on clinical profile and treatment outcomes for patients with Stage IV adenocarcinoma of lung. AIM: We aimed to prospectively study the clinical profile and treatment outcomes for patients with Stage IV adenocarcinoma of lung at a tertiary cancer center. MATERIALS AND METHODS: One hundred and ninetyfour patients with Stage IV adenocarcinoma of lung were prospectively analyzed for demographic and molecular profile (epidermal growth factor receptor [EGFR] and echinodermal microtubuleassociated proteinlike 4anaplastic lymphoma kinase [EML4ALK] mutations). Patients with EGFR and EML4ALK mutations were treated with tyrosine kinase inhibitors. Patients without these mutations were treated with standard chemotherapy regimens. Maintenance chemotherapy was offered to patients as per standard guidelines. Clinical outcomes measured were response rate (RR), progressionfree survival (PFS), and overall survival (OS). RESULTS: Median age of patients was 56 years (range, 26-82) with a male:female ratio of 2.3:1. EGFR and ALK mutation testing was feasible in 169 (87.1%) and 164 (84.5%), respectively, and detected in 37.9% and 5.5% patients, respectively. Overall RR, PFS and OS of whole cohort were 44.3%, 6.9, and 15.5 months, respectively. PFS and OS of mutated group (EGFR, EML4ALK) were longer than nonmutated group (10.5 vs. 5.4 months, P < 0.0001 and 21.5 vs. 11 months, P = 0.0001, respectively). PFS and OS of patients who received pemetrexed maintenance were longer than those who did not receive maintenance (8.5 vs. 6.5 months, P = 0.1613 and 18.5 vs. 12.5 months, P = 0.0219, respectively). CONCLUSIONS: Mutation testing at diagnosis is feasible in the vast majority of patients with Stage IV adenocarcinoma of the lung. Patients with EGFR or EML4ALK mutation and those who received pemetrexed maintenance had better clinical outcomes.

Investigations on the effect of gamma-ray irradiation on the gas sensing properties of SnO2 nanoparticles.

In recent years, SnO2 nanoparticles (NPs) have been subjected to various modifications in order to improve their performance in sensing and other applications. Here, we report the synthesis of SnO2 NPs by microwave irradiation, and subsequent exposure to gamma (γ) radiation at different doses (0-150 kGy) to induce desirable physico-chemical properties. The irradiated samples were characterized by x-ray powder diffraction (XRD), transmission electron microscopy (TEM and HR-TEM), and photoluminescence (PL) to evaluate the effect of γ-ray irradiation on their morphology and microstructure. The results revealed that the bulk crystal structure remained unchanged after irradiation, while the existence of defects and a damaged over-layer have been confirmed by PL and HR-TEM respectively. The influence of γ-irradiation on the electrical and CO sensing characteristics was also investigated in the temperature range between 150 and 400 °C. γ-irradiated SnO2 NP based resistive sensors showed better CO sensing characteristics (i.e. higher response and lower working temperature) compared to non-irradiated SnO2. Upon optimizing the γ-ray dose irradiation level and working temperature, a ten-fold enhancement in the response to CO has been achieved (R/R 0 = 12 to 50 ppm of CO in air) in 50 kGy irradiated SnO2 NP based sensors operating at 150 °C. A possible mechanism for the enhanced sensing performance of γ-irradiated SnO2 NPs has been proposed.

An ultrasensitive electrochemical sensor for simultaneous determination of xanthine, hypoxanthine and uric acid based on Co doped CeO2 nanoparticles.

A novel electrochemical sensor has been fabricated using Co doped CeO2 nanoparticles for selective and simultaneous determination of xanthine (XA), hypoxanthine (HXA) and uric acid (UA) in a phosphate buffer solution (PBS, pH5.0) for the first time. The Co-CeO2 NPs have been prepared by microwave irradiation method and characterized by Powder XRD, Raman spectroscopy, HRTEM and VSM measurements. The electrochemical behaviours of XA, HXA and UA at the Co-CeO2 NPs modified glassy carbon electrode (GCE) were studied by cyclic voltammetry and square wave voltammetry methods. The modified electrode exhibited remarkably well-separated anodic peaks corresponding to the oxidation of XA, HXA and UA over the concentration range of 0.1-1000, 1-600 and 1-2200µM with detection limits of 0.096, 0.36, and 0.12µM (S/N=3), respectively. For simultaneous detection by synchronous change of the concentrations of XA, HXA and UA, the linear responses were in the range of 1-400µM each with the detection limits of 0.47, 0.26, and 0.43µM (S/N=3), respectively. The fabricated sensor was further applied to the detection of XA, HXA and UA in human urine samples with good selectivity and high reproducibility.

A novel disposable electrochemical sensor for determination of carbamazepine based on Fe doped SnO2 nanoparticles modified screen-printed carbon electrode.

An effective strategy to fabricate a novel disposable screen printing carbon electrode modified by iron doped tin dioxide nanoparticles for carbamazepine (CBZ) detection has been developed. Fe-SnO2 (Fe=0 to 5 wt.%) NPs were synthesized by a simple microwave irradiation method and assessed for their structural and morphological changes due to Fe doping into SnO2 matrix by X-ray diffraction and scanning and transmission electron microscopy. The electrochemical behaviour of carbamazepine at the Fe-SnO2 modified screen printed carbon electrode (SPCE) was investigated by cyclic voltammetry and square wave voltammetry. Electron transfer coefficient α (0.63) and electron transfer rate constant ks (0.69 s(-1)) values of the 5 wt.% Fe-SnO2 modified SPCE indicate that the diffusion controlled process takes place on the electrode surface. The fabricated sensor displayed a good electrooxidation response towards the detection of CBZ at a lower oxidation potential of 0.8 V in phosphate buffer solution at pH7.0. Under the optimal conditions, the sensor showed fast and sensitive current response to CBZ over a wide linear range of 0.5-100 µM with a low detection limit of 92 nM. Furthermore, the practical application of the modified electrode has been investigated by the determination of CBZ in pharmaceutical products using standard addition method.

Fabrication of folic acid sensor based on the Cu doped SnO2 nanoparticles modified glassy carbon electrode.

A novel folic acid biosensor has been fabricated using Cu doped SnO2 nanoparticles (NPs) synthesized by a simple microwave irradiation method. Powder XRD and TEM studies confirmed that both the pure and Cu doped SnO2 (Cu: 0, 10, 20wt%) crystallized in tetragonal rutile-type structure with spherical morphology. The average crystallite size of pure SnO2 was estimated to be around 16 nm. Upon doping, the crystallite sizes decreased to 9 nm and 5 nm for 10 and 20wt% Cu doped SnO2 respectively. XPS studies confirmed the electronic state of Sn and Cu to be 4+ and 2+ respectively. Cu (20wt%) doped SnO2 NPs are proved to be a good sensing element for the determination of folic acid (FA). Cu-SnO2 NPs (20wt%) modified glassy carbon electrode (GCE) exhibited the lowest detection limit of 0.024 nM over a wide folic acid concentration range of 1.0 × 10(-10) to 6.7 × 10(-5) M at physiological pH of 7.0. The fabricated sensor is highly selective towards the determination of FA even in the presence of a 100 fold excess of common interferent ascorbic acid. The sensor proved to be useful for the estimation of FA content in pharmaceutical sample with satisfactory recovery.

Development of amperometric L-tyrosine sensor based on Fe-doped hydroxyapatite nanoparticles.

A novel biosensor based on Fe-doped hydroxyapatite (Fe-HA) nanoparticles and tyrosinase has been developed for the detection of L-tyrosine. Nanostructured Fe-HA was synthesized by a simple microwave irradiation method, and its phase formation, morphology and magnetic property were examined by powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). Electrochemical performance of the nano Fe-HA/tyrosinase modified glassy carbon electrode (GCE) for detection of L-tyrosine was investigated by cyclic voltammetry (CV) and amperometric methods. The fabricated biosensor exhibited a linear response to L-tyrosine over a wide concentration range of 1.0×10(-7) to 1.0×10(-5) M with a detection limit of 245 nM at pH 7.0. In addition, the fabricated sensor showed an excellent selectivity, good reproducibility, long-term stability and anti-interference towards the determination of L-tyrosine.

Peripheral adenomatoid odontogenic tumour - is it really peripheral?: a case report.

A Peripheral Adenomatoid Odontogenic Tumour (PAOT) is quite a rare entity which has been infrequently reported in the literature. These uncommon clinical variants of an Adenomatoid Odontogenic Tumour (AOT), typically manifest as a soft tissue mass of the gingiva, which mimick a common epulis, but yet have an identical histopathologic presentation as their intraosseous counterpart. These lesions, though they are indolent in nature, have a tendency to cause well defined deep bony pockets. Only fourteen cases have been adequately documented so far. We are reporting a case of a PAOT of the anterior maxillary gingiva, with a periodontal bone defect in a 12 year old girl. The relevant literature has been briefly reviewed, with an insight into the probable origin of PAOTs with bony defects.

Fabrication of Cr doped SnO2 nanoparticles based biosensor for the selective determination of riboflavin in pharmaceuticals.

We report the fabrication and testing of a riboflavin (RF) biosensor based on the use of Cr doped SnO2 nanoparticles. The Cr-SnO2 nanoparticles with chromium concentration from 0 to 5 wt% were synthesised by a microwave irradiation method. Magnetic studies revealed that only 3 wt% Cr doped nano-SnO2 has ferromagnetic behaviour at room temperature. This Cr-SnO2 nanoparticles modified electrode responded to RF linearly over a concentration range of 0.2 × 10(-6) to 1.0 × 10(-4) M with a detection limit of 107 nM. The fabricated sensor showed an excellent anti-interference ability against electroactive species and metal ions and proved to be useful for the estimation of the RF content in pharmaceutical samples with satisfactory recovery.

Fabrication of hydrogen peroxide biosensor based on Ni doped SnO2 nanoparticles.

Ni doped SnO(2) nanoparticles (0-5 wt%) have been prepared by a simple microwave irradiation (2.45 GHz) method. Powder X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies confirmed the formation of rutile structure with space group (P(42)/mnm) and nanocrystalline nature of the products with spherical morphology. Direct electrochemistry of horseradish peroxidase (HRP)/nano-SnO(2) composite has been studied. The immobilized enzyme retained its bioactivity, exhibited a surface confined, reversible one-proton and one-electron transfer reaction, and had good stability, activity and a fast heterogeneous electron transfer rate. A significant enzyme loading (3.374×10(-10) mol cm(-2)) has been obtained on nano-Ni doped SnO(2) as compared to the bare glassy carbon (GC) and nano-SnO(2) modified surfaces. This HRP/nano-Ni-SnO(2) film has been used for sensitive detection of H(2)O(2) by differential pulse voltammetry (DPV), which exhibited a wider linearity range from 1.0×10(-7) to 3.0×10(-4)M (R=0.9897) with a detection limit of 43 nM. The apparent Michaelis-Menten constant (K(M)(app)) of HRP on the nano-Ni-SnO(2) was estimated as 0.221 mM. This excellent performance of the fabricated biosensor is attributed to large surface-to-volume ratio and Ni doping into SnO(2) which facilitate the direct electron transfer between the redox enzyme and the surface of electrode.

Oral lichen planus: An update on pathogenesis and treatment.

Oral lichen planus (OLP) is a chronic inflammatory disease that affects the mucus membrane of the oral cavity. It is a T-cell mediated autoimmune disease in which the cytotoxic CD8+ T cells trigger apoptosis of the basal cells of the oral epithelium. Several antigen-specific and nonspecific inflammatory mechanisms have been put forward to explain the accumulation and homing of CD8+ T cells subepithelially and the subsequent keratinocyte apoptosis. A wide spectrum of treatment modalities is available, from topical corticosteroids to laser ablation of the lesion. In this review, we discuss the various concepts in the pathogenesis and current treatment modalities of OLP.

2,3,6-Triphenyl-piperidin-4-one.

In the title mol-ecule, C(23)H(21)NO, the piperidine ring adopts a chair conformation, with the N and carbonyl C atoms as flaps, which deviate on either side of the chair by -0.706 (3) and 0.494 (3) Å, respectively. All three phenyl rings are in equatorial positions on the piperidine ring, making angles with the puckering plane of 73.5 (1), 73.1 (1) and 67.2 (1)°. Though there is no classical hydrogen bonding, the crystal is stabilized by inter-molecular C-H⋯π contacts and π-π stacking inter-actions involving phenyl rings [centroid-centroid distance = 4.424 (2) Å].

Island of salivary gland in adipose tissue: a report of three cases.

Although uncommon, many variants of lipomatous lesions in or around salivary glands have been reported in the literature. We report a series of three such cases in the minor salivary gland region. The first case (oral floor) is a well-circumscribed lipocytic lesion admixed with glandular components (mucous acini, serous demilunes and ducts). The second case (alveolar mucosa) is a diffuse lipomatous proliferation with entrapped salivary glandular elements, muscles and blood vessels. The third case (palate) is similar to the first case but the gland is located at the periphery of the lesion. The purpose of the article was to report these three lesions and discuss in relation to other pertaining lipomatous lesions (sialolipoma, lipoadenoma, lipomatosis, lipometaplasia in pleomorphic adenoma and infiltrating lipoma).