Crystal Chemistry and Photoluminescent Aspects of Bright Orange Light Emitting Sm3+- Activated Ba2BiV3O11 Nanomaterials for Advanced Illuminating Applications.

In the present system, Sm3+ activated Ba2BiV3O11 nanomaterial series radiating orange-red light was developed via an efficient approach of solution combustion method. The structural examinations using XRD analysis indicate that the sample is crystallized into the monoclinic phase with the P21/a (14) space group. The elemental composition and morphological conduct were studied via energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM) respectively. Also, the formation of nanoparticles was confirmed by transmission electron microscopy (TEM). Photoluminescent (PL) examinations reveal the orange-red emission from the developed nanocrystals via documenting the emission spectra, which reveals the peak at 606 nm due to the 4G5/2 → 6H7/2 transition. Further, the decay time, non-radiative rates, quantum efficiency, and band gap of the optimal sample were computed as 1.3263 ms, 219.5 s- 1, 70.88%, and 3.41 eV respectively. Finally, the chromatic parameters including color - coordinates (0.5565, 0.4426), 1975 K color correlated temperature (CCT), and color purity (85.58%) reflected their excellent luminous performance. The above-mentioned outcomes endorsed the relevancy of the developed nanomaterials as a propitious agent in the engineering of advanced illuminating optoelectronic appliances.

Crystal Phase Refinement and Optical Features of Highly Efficient Green Light Radiating Ca9Y(VO4)7: Er3+ Nanophosphors for Emerging Solid-state Lighting Applications.

Ca9Y(VO4)7 phosphor activated with Er3+ ions have been developed by the urea-aided solution combustion technique. XRD profiles assisted with Rietveld refinement executed over-developed Er3+-activated Ca9Y(VO4)7 powder, revealed a trigonal phase with the R3c space group. The electron microscope techniques namely TEM and SEM characterize the size and surface-linked qualities of the developed nanopowder, respectively. The uniform distribution of various elements in the nanocrystalline sample is authenticated by an energy-dispersive spectroscopy (EDS) system. The Eg (band gap) value of 3.64 eV for Ca9Y0.9Er0.1(VO4)7 and 3.74 eV for Ca9Y(VO4)7 has been estimated. Upon 382 nm excitation, Er3+: Ca9Y(VO4)7 phosphor gives rise to the bright green emission owing to the 4S3/2 → 4I15/2 transition. The concentration quenching after 10 mol% composition of trivalent erbium ions is attributed to dipole-dipole interlinkages in accordance with Dexter's theory. The radiative lifetime (1.1083 ms), non-radiative rates (0.2079 ms- 1), quantum efficiency (79%), along with colorimetric parameters i.e. CIE x (= 0.2577), y (= 0.4566), and CCT quantities offer Ca9Y0.9Er0.1(VO4)7 as a proficient green radiating nanomaterial for RGB phosphors in solid-state applications.

Combustion Synthesis and Study of Double Charge Transfer in Highly Efficient Cool White-emitting Dy3+ Activated Vanadate-based Nanophosphor for Advanced Solid-state Lighting.

A series of Ca9Gd(VO4)7: Dy3+ (x = 0.01-0.20) nanophosphor crystals emitting a cool white light were synthesized by solution combustion methodology. The X-ray diffraction patterns were analyzed and processed using Rietveld refinement. The fabricated nanophosphor was found to crystallize in a trigonal crystal lattice with space group R3c(161). The morphological behavior of the prepared nanophosphor was investigated using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The photoluminescence properties of the nanophosphor correspond to cool white emission upon near-ultraviolet (NUV) excitation at 327 nm due to 4F9/2 → 6H15/2 (bluish) and 4F9/2 → 6H13/2 (yellowish) radiative relaxations at 487 nm and 576 nm respectively. Also, there is a strong occurrence of double charge transfer from O2- ions to Dy3+ and V5+ ions with the latter being stronger due to the high positive charge of V5+ ions. Color coordinates (x = 0.2878, y = 0.3259) are consistent with white emission. Auzel's model was implemented to examine the non-radiative relaxation (113.5 ms-1), radiative lifetime (1.4856 ms), and quantum efficiency (83.13%) values. The crystalline and optical behavior of the synthesized cool white emitting nanophosphor facilitates its use in near-UV-based WLEDs and other advanced solid-state lighting.

Leptomeningeal carcinomatosis in a patient with recurrent unresectable squamous cell carcinoma of the retromolar trigone-a brief report.

BACKGROUND: The reported incidence of leptomeningeal carcinomatosis is 3-8% in patients with solid tumours. More commonly, it has been described in the setting of advanced cancers of the lung, breast and malignant melanoma. CASE PRESENTATION: A 50-year-old diabetic patient with recurrent unresectable squamous cell carcinoma (SCC) of the right retromolar trigone (rT4bN0M0) presented with severe low backache and weakness in bilateral lower limbs 20 days after the completion of concurrent chemoradiotherapy. Contrast-enhanced MRI of the spine showed multiple nodular enhancing leptomeningeal lesions at the lumbar level and an intramedullary T2/FLAIR-hyperintense longitudinal lesion involving the central cord from C2 to C7 vertebral levels, suggestive of leptomeningeal metastases. Cerebrospinal fluid (CSF) analysis revealed pleocytosis, elevated protein and markedly decreased glucose. The CSF cytology revealed scattered large atypical cells, suspicious for metastasis. Non-contrast MRI of the brain showed a T2/FLAIR-hyperintense lesion involving the right caudate nucleus suggestive of either an acute infarct with haemorrhagic transformation or a haemorrhagic brain metastasis. During assessment, he had high-grade fever and was started on empirical intravenous antibiotics (ceftriaxone, vancomycin and subsequently meropenem) in line with the management for acute bacterial meningitis. Gram staining of CSF did not demonstrate the presence of any bacteria and the specimen was sterile on culture. He did not respond to empirical antibiotics, had a progressive downhill course and eventually died due to aspiration pneumonia. CONCLUSION: This brief report highlights the importance of awareness of leptomeningeal carcinomatosis as a possible cause of backache with sensorimotor deficit and autonomic dysfunction in a previously treated case of head and neck SCC.

Photoluminescence performance of green light emitting terbium (III) complexes with ß-hydroxy ketone and nitrogen donor ancillary ligands.

An efficient and cost-effective technique, solution precipitation approach is adopted to synthesize five bright green luminescent terbium (III) complexes by employing the main ß-hydroxy ketone ligand, 2-hydroxy-4-ethoxyacetophenone, and ancillary ligands like bathophenanthroline, 5,6-dimethyl-1,10-phenanthroline, 1,10-phenanthroline, and 2,2-bipyridyl. The elemental compositions and binding mode of ligand to terbium (III) ion can be validated by using energy dispersive X-ray analysis, elemental analysis, Fourier transform infrared, and proton nuclear magnetic resonance spectroscopy. The complexes are thermally stable up to 158°C and possess the cubic shaped particles as confirmed by thermogravimetric analysis and scanning electron microscopic study, respectively. The band-gap energy (3.02-2.92 eV) of complexes is reckoned through diffuse reflectance spectra, which tailors them as potential candidates in the field of military radars. The photoluminescence studies unveil that the complexes exhibit the bright green luminescence corresponding to 5 D4 → 7 F5 transition of Tb3+ ion (548 nm) under the excitation wavelength of 395 or 397 nm. The Commission International de I'Eclairage chromaticity coordinates (x, y) and color purity substantiates the green emission of complexes. The energy transfer mechanism elucidates that the main ligand and ancillary ligands sensitize Tb3+ ion, which in turn enhances the luminescence efficiency of the emissive layer of white organic light emitting diodes. The results reveal that the complexes are considered as good contenders in the field of display devices and laser technology. Lastly, in vitro antimicrobial and antioxidant activity proclaim the potent antimicrobial and antioxidant actions of complexes via tube dilution and 2, 2-diphenyl-1-picrylhydrazyl assays, respectively.

Role of Cytokines as Molecular Marker of Dengue Severity.

OBJECTIVE: Dengue infection is a rapidly spreading vector-borne disease and is endemic in the Indian subcontinent. It has varied manifestations ranging from subclinical infection to severe fatal shock syndrome. This study aimed to estimate cytokine level in dengue patients and correlate them with dengue severity. METHODS: Cases of dengue fever diagnosed in the department of medicine of our institute from July 2015 to November 2016 were included in the study. The clinical features, biochemical, hematological and radiological parameters along with cytokine levels (Interferon-gamma, Interleukin-6, and Tumour Necrosis Factor-alpha) were recorded in all patients. RESULTS: Out of 80 confirmed cases of dengue included in the study, 50 had nonsevere dengue (Group 1), and 30 patients had severe dengue (Group 2). The median level of serum TNF-α in group 2 (62.5 pg/mL) was significantly higher than the median level in group 1 (20 pg/mL), (p=0.043). Similarly, the median level of serum IFN-γ in group 2 (10.25 pg/mL) was significantly higher than the median level in group 1 (8.5 pg/mL), (p=0.002). The median level of IL-6 was also higher in group 2 (29 pg/ml) as compared group 1(14.2 pg/ml), but this result was not significant (p>0.05). CONCLUSION: Some cytokines may play a role in the pathogenesis of severe manifestations of dengue.

Oral health knowledge, awareness and associated practices of pre-school children's mothers in Greater Noida, India.

AIM: To assess the oral health knowledge, awareness and associated exercised practices of pre-school children's mothers in Greater Noida, India. SUBJECTS AND METHODS: The sampling frame for this study was chosen via convenient sampling. It comprised 598 mothers of children aged between 2 and 5 years, attending the paediatrics division of a government and four private hospitals in Greater Noida. A pre-tested questionnaire was distributed to the participants which comprised questions on the participant's sociodemographic characteristics and 23 statements regarding their knowledge, attitude and practices towards their child's oral health. Data were analysed using SPSS 21.0. P < 0.05 was considered statistically significant. RESULTS: The study showed that merely 24.9% of the participating mothers had good knowledge and 29.1% and 12.5% exhibited poor attitude and practices, respectively, towards their child's oral health. Knowledge about the role of fluorides, causes and prevention of dental caries, gum disease, malocclusion, appropriate timing of commencing of toothbrushing and importance of frequent dental visit was found to be inadequate among the participants. The knowledge varied significantly with respect to age (P = 0.04), education (P = 0.00) and working status (P = 0.006) of the mothers. CONCLUSION: The study participants exhibited poor knowledge and attitude towards their child's oral heath which was leading to the adoption of poor oral health practices by these mothers. Thus, to improve the oral health of children, appropriate practices and measures should be promoted among their parents/guardians.

Laryngeal Leishmaniasis with Extra-pulmonary Tuberculosis.

Clinical presentations of Leishmania infection include visceral (most common form), cutaneous, mucocutaneous, mucosal and post-kala-azar dermal leishmaniasis. Mucosal form of leishmaniasis mostly involves oral and nasal mucosa. Rarely, laryngeal and pharyngeal mucosa may also be involved. Its concomitant presence with tuberculosis (TB), a disease rampant in India, is uncommon. Here we are reporting a case of isolated laryngeal leishmaniasis associated with extra-pulmonary tuberculosis (EPTB), with approach to diagnosis and treatment in a tropical resource-limited setting.