High dose rate brachytherapy in nasopharyngeal carcinoma: a neglected practice

Nasopharyngeal carcinomas (NPCs) are one of the most chemo- and radio- sensitive cancers of the head and neck region. It differs from other head and neck cancers in terms of signs and symptoms, treatment response and overall survival. Surgery is not the preferred treatment option, with chemoradiation being the treatment of choice, with an excellent local control rate, prognosis and overall survival. But the management of recurrent NPC is quite challenging and the treatment options available includes re-irradiation, chemotherapy, brachytherapy or surgery in rare cases. Re-irradiation in case of recurrent NPC is very difficult due to the already irradiated tissue in the radiation path, but re-irradiation with brachytherapy is an excellent treatment option for giving further doses of radiation to the nasopharynx in cases of recurrence or residual disease, by taking in consideration the already irradiated area and the radiation dose given before, and achieving a good local control rate and overall survival

A five-year retrospective analysis of clinical, pathological and treatment aspects on stomach cancer from a regional cancer centre in north east India

Background: Stomach cancer is the fifth most common cancer in the world, which generally presents in advanced stage and have poor prognosis. Methods: Retrospective study including 101 cases was done at the Regional Cancer Centre in North East India from January, 2018 to December, 2022 on the clinical, pathological and treatment aspects of stomach cancer. Results: Median age of diagnosis was 59 years, with high male: female ratio. Most common risk factor was tobacco smoking and chewing. Most common symptom was pain abdomen followed by nausea or vomiting. Antrum was the most common tumor location, and gastric outlet obstruction was present in 10.9% patients. Histologically, all patients had adenocarcinoma, with metastasis found in 47 patients. Out of the 101 patients enrolled in the study, 50 patients were treated with curative intent and the remaining 51 patients were treated with palliative intent. Patients were treated with surgery, preoperative/ adjuvant/ palliative chemotherapy and/or curative/ palliative radiotherapy. Conclusions: This study showed tobacco use as an important risk factor for stomach cancer. Majority of our patients were diagnosed at an advanced stage, thus having poor prognosis. Hence, avoidance of risk factors, early detection of signs and symptoms, and aggressive treatment with surgery, chemotherapy, and/ or radiotherapy is required for management of stomach cancer

Role of ambient air on photoluminescence and electrical conductivity of assembly of ZnO Nanoparticles

Effect of ambient gases on photoluminescence (PL) and electrical conductivity of films prepared using ZnO nanoparticles (NPs) have been investigated. It is observed that NPs of size below 20 nm kept inside a chamber exhibit complete reduction in their visible PL when oxygen partial pressure of the surrounding gases is decreased by evacuation. However the visible PL from ZnO NPs is insensitive to other major gases present in the ambient air. The rate of change of PL intensity with pressure is inversely proportional to the ambient air pressure and increases when particle size decreases due to the enhanced surface to volume ratio. On the other hand an assembly of ZnO NPs behaves as a complete insulator in the presence of dry air and its major components like N2, O2 and CO2. Electrical conduction having resistivity ~102 - 103 {\Omega}m is observed in the presence of humid air. The depletion layer formed at the NP surface after acquiring donor electrons of ZnO by the adsorbed oxygen, has been found to control the visible PL and increases the contact potential barrier between the NPs which in turn enhances the resistance of the film.Comment: arXiv admin note: significant text overlap with arXiv:1008.249

Synthesis and down conversion emission property of Eu3+ doped LaAlO3 CsAlO2 and LiLaO2 phosphors

[EN] LaAlO3:Eu3+, CsAlO2:Eu3+ and LiLaO2:Eu3+ phosphors with varying concen- trations of Eu3+ from 3 to 10 mol% were prepared by combustion synthesis method and the samples were further heated to 1,000ºC to improve the crystallinity of the materials. The structure and morphology of materials have been examined by X-ray diffraction and scan- ning electron microscopy. SEM images depicted that the morphology of crystallites have no uniform shapes and sizes. Small and coagulated particles of irregular shapes of different sizes are obtained. The characteristic emissions of Eu3+ were clearly observed at nearly 580, 592, 650, 682 to 709 (multiplet structure) nm for 5D - 7 Fn transitions where n = 0, 1, 3, 4 respectively, including the strongest emission peaks at 614 and 620 nm for 5 D0 - 7 F2 transitions in CsAlO2:Eu3+ and LiLaO2:Eu3+ host lattices. The intensity of emission peak corresponding to 5 D0 !→ 7 F1 transitions in LaAlO3 :Eu3+ material is comparable to that of 5D0 5D-7F2 transitions which is also a singlet. Photoluminescence intensity follows the order as in LiLaO2 > LaAlO3 > CsAlO2 lattices. Remarkable high photoluminescence intensity with 7 mol% doping of Eu3+ in LiLaO2 makes it a strong contender for red colored display applications.This work was supported by the European Commission through Nano CIS project (FP7-PEOPLE-2010-IRSES ref. 269279).Marí Soucase, B.; Singh, KC.; Moya Forero, MM.; Singh, I.; Om, H.; Chand, S. (2015). Synthesis and down conversion emission property of Eu3+ doped LaAlO3 CsAlO2 and LiLaO2 phosphors. Optical and Quantum Electronics. 47(7):1569-1578. https://doi.org/10.1007/s11082-014-9997-9S15691578477Abbattista, F., Vallino, M.: Remarks on the $$\text{La}_{2}\text{O}_{3}-\text{Li}_{2}\text{O}$$ La 2 O 3 - Li 2 O binary system between 750 and 1,000  $$^{\circ}$$ ∘ C. Ceram. Int. 9, 35–38 (1983)Bae, Y., Lee, K., Byeon, S.: Synthesis and $$\text{Eu}^{3+}$$ Eu 3 + concentration-dependent photoluminescence of $$\text{Gd}_{\rm 2-x}\text{Eu}_{\rm x}\text{O}_{3}$$ Gd 2 - x Eu x O 3 nanowires. J. Lumin. 129, 81–85 (2009)Blasse, G., Grambier, B.: Luminescent Materials, vol. 43. Springer, Berlin, pp. 43–46 (1994)Dereń, P., Krupa, J.: Spectroscopic investigations of $$\text{LaAlO}_{3}$$ LaAlO 3 : $$\text{Eu}^{3+}$$ Eu 3 + . J. Lumin. 102–103, 386–390 (2003)Ekambaram, S., Patil, K.: Synthesis and properties of $$\text{Eu}^{2+}$$ Eu 2 + activated blue phosphors. J. Alloys Compd. 248, 7–12 (1997)Gao, X., Lei, L., Lv, C., Sun, Y., Zheng, H., Cui, Y.: Preparation and photoluminescence property of a loose powder, $$\text{Ca}_{3}\text{Al}_{2}\text{O}_{6}$$ Ca 3 Al 2 O 6 : $$\text{Eu}^{3+}$$ Eu 3 + by calcination of a layered double hydroxide precursor. J. Solid State Chem. 181, 1776–1781 (2008)Hayakawa, T., Kamt, N., Yamada, K.: Visible emission characteristics in $$\text{Tb}^{3+}$$ Tb 3 + -doped fluorescent glasses under selective excitation. J. Lumin. 68, 179–186 (1996)Hreniak, D., Strek, W., Dereń, P., Bednarkiewicz, A., Łukowiak, A.: J. Alloys Compd. 408, 828–830 (2006)Huang, Y., Jiang, C., Cao, Y., Shi, L., Seo, H.: Luminescence and microstructures of $$\text{Eu}^{3+}$$ Eu 3 + -doped in triple phosphate $$\text{Ca}_{8}\text{MgR}(\text{PO}_{4})_{7}$$ Ca 8 MgR ( PO 4 ) 7 (R = La, Gd, Y) with whitlockite structure. Mater. Res. Bull. 44, 793–798 (2009)Kharbache, H., Mahiou, R., Boutinaud, P., Boyer, D., Zakaria, D., Deren, P.: Experimental evidence of $$\text{Eu}^{3+}$$ Eu 3 + pairs in $$\text{K}_{2}\text{EuF}_{5}$$ K 2 EuF 5 . Opt. Mater. 31, 558–561 (2009)Kijima, T., Shinbori, T., Sekita, M., Uota, M., Sakai, G.: Abnormally enhanced $$\text{Eu}^{3+}$$ Eu 3 + emission in $$\text{Y}_{2}\text{O}_{2}\text{SO}_{4}$$ Y 2 O 2 SO 4 : $$\text{Eu}^{3+}$$ Eu 3 + inherited from their precursory dodecylsulfate-templated concentric-layered nanostructure. J. Lumin. 128, 311–316 (2008)Liu, G., Hong, G., Wang, J., Dong, X.: Hydrothermal synthesis of spherical and hollow $$\text{Gd}_{2}\text{O}_{3}$$ Gd 2 O 3 : $$\text{Eu}^{3+}$$ Eu 3 + phosphors. J. Alloys Compd. 432, 200–204 (2007)Mączka, M., Bednarkiewicz, A., Mendoza-Mendoza, E., Fuentes, A.F., Kępiński, L.: Optical properties of Eu and Er doped $$\text{LaAlO}_{3}$$ LaAlO 3 nanopowders prepared by low-temperature method. J. Solid State Chem. 194, 264–269 (2012)Mao, Z., Wang, D., Lu, Q., Yu, W., Yuan, Z.: Tunable single-doped single-host full-color-emitting $$\text{LaAlO}_{3}$$ LaAlO 3 : $$\text{Eu}$$ Eu phosphor via valence state-controlled means. Chem. Commun. 3, 346–348 (2009)Mao, Z.Y., Wang, D.J., Liu, Y.H., Fei, Q.N., Zheng, X., Xu, S.C., Qiu, K.: Tuning the color purity of $$\text{LaAlO}_{3}$$ LaAlO 3 : $$\text{Eu}^{3+}$$ Eu 3 + red phosphor by the cross relaxation. Opto Electron. Lett. 6, 116–119 (2010)Marí, B., Singh, K., Sahal, M., Khatkar, S., Taxak, V., Kumar, M.: Preparation and luminescence properties of $$\text{Tb}^{3+}$$ Tb 3 + doped $$\text{ZrO}_{2}$$ ZrO 2 and $$\text{BaZrO}_{3}$$ BaZrO 3 phosphors. J. Lumin. 130, 2128–2132 (2010)Marí, B., Singh, K.C., Cembrero-Coca, P., Singh, I., Singh, D., Chand, S.: Red emitting $$\text{MTiO}_{3}$$ MTiO 3 (M = Ca & Sr) phosphor doped with $$\text{Eu}^{+3}$$ Eu + 3 or $$\text{Pr}^{+3}$$ Pr + 3 with some cations as co-dopands. Displays 34, 346–351 (2013)Ningthoujam, R., Sudarsan, V., Kulshreshtha, S.: $$\text{SnO}_{2}$$ SnO 2 : $$\text{Eu}$$ Eu nanoparticles dispersed in silica: A low-temperature synthesis and photoluminescence study. J. Lumin. 127, 747–756 (2007)Ogasawara, K., Watanabe, S., Toyoshima, H., Brik, M.G.: Handbook on Physics and Chemistry of Rare Earths, vol. 1. Elsevier, Amsterdam (2007)Pereyra-Perea, E., Estrada-Yañez, M.R., García, M.: Preliminary studies on luminescent terbium-doped ZrO2 thin films prepared by the sol-gel process. J. Phys. D 31, 7–10 (1998)Perez, D., Vegas, A.: The Zintl-Klemm concept applied to cations in oxides. I. The structures of ternary aluminates. Acta Cryst. B 59, 305–323 (2003)Pieterson, L., Heeroma, M., Heer, E., Meijerink, A.: Charge transfer luminescence of $$\text{Yb}^{3+}$$ Yb 3 + . J. Lumin. 91, 177–193 (2000)Shi, C., Shi, J., Deng, J., Han, Z., Zhou, Y., Zhang, G.: Excitation states of $$\text{RE}^{3+}$$ RE 3 + -pentaphosphates in VUV and UV range. J. Electron. Spectros. Relat. Phenomena 79, 121–124 (1996)Singh, V., Watanabe, S., Gundu Rao, T.K., Chubaci, J.F.D., Kwak, H.-Y.: Characterization, photoluminescence, thermally stimulated luminescence and electron spin resonance studies of $$\text{Eu}^{3+}$$ Eu 3 + doped $$\text{LaAlO}_{3}$$ LaAlO 3 phosphor. Solid State Sci. 13, 66–71 (2011)Solovyev, O.V., Malkin, B.Z.: Modeling of electron-vibrational $$4\text{f}^{\rm n}-4\text{f}^{{\rm n}-1}5\text{d}$$ 4 f n - 4 f n - 1 5 d spectra in $$\text{LiYF}_{4}$$ LiYF 4 : $$\text{RE}^{3+}$$ RE 3 + crystals. J. Mol. Struct. 838, 176–181 (2007)Zhang, Y., Li, W., Jingjun, X.: Structure and photoluminescence properties of $$\text{KSr}_{4}(\text{BO}_{3})_{3}$$ KSr 4 ( BO 3 ) 3 : $$\text{Eu}^{3+}$$ Eu 3 + red-emitting phosphor. Opt. Mater. Express 2(2012), 92–102 (2012)Zhou, L., Yan, B.: Sol-gel synthesis and photoluminescence of $$\text{CaSiO}_{3}$$ CaSiO 3 : $$\text{Eu}^{3+}$$ Eu 3 + nanophosphors using novel silicate sources. J. Phys. Chem. Solids 69, 2877–2882 (2008

Effects of crystallization and dopant concentration on the emission behavior of TiO2:Eu nanophosphors

Uniform, spherical-shaped TiO2:Eu nanoparticles with different doping concentrations have been synthesized through controlled hydrolysis of titanium tetrabutoxide under appropriate pH and temperature in the presence of EuCl3·6H2O. Through air annealing at 500°C for 2 h, the amorphous, as-grown nanoparticles could be converted to a pure anatase phase. The morphology, structural, and optical properties of the annealed nanostructures were studied using X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy [EDS], and UV-Visible diffuse reflectance spectroscopy techniques. Optoelectronic behaviors of the nanostructures were studied using micro-Raman and photoluminescence [PL] spectroscopies at room temperature. EDS results confirmed a systematic increase of Eu content in the as-prepared samples with the increase of nominal europium content in the reaction solution. With the increasing dopant concentration, crystallinity and crystallite size of the titania particles decreased gradually. Incorporation of europium in the titania particles induced a structural deformation and a blueshift of their absorption edge. While the room-temperature PL emission of the as-grown samples is dominated by the 5D0 - 7Fj transition of Eu+3 ions, the emission intensity reduced drastically after thermal annealing due to outwards segregation of dopant ions

A Range of Earth Observation Techniques for Assessing Plant Diversity

AbstractVegetation diversity and health is multidimensional and only partially understood due to its complexity. So far there is no single monitoring approach that can sufficiently assess and predict vegetation health and resilience. To gain a better understanding of the different remote sensing (RS) approaches that are available, this chapter reviews the range of Earth observation (EO) platforms, sensors, and techniques for assessing vegetation diversity. Platforms include close-range EO platforms, spectral laboratories, plant phenomics facilities, ecotrons, wireless sensor networks (WSNs), towers, air- and spaceborne EO platforms, and unmanned aerial systems (UAS). Sensors include spectrometers, optical imaging systems, Light Detection and Ranging (LiDAR), and radar. Applications and approaches to vegetation diversity modeling and mapping with air- and spaceborne EO data are also presented. The chapter concludes with recommendations for the future direction of monitoring vegetation diversity using RS

Disappearance and recovery of luminescence in GdPO4:Eu3+ nanorods: Propose to water/OH center dot release under near infrared and gamma irradiations

Luminescence intensity of rare-earth doped materials can be varied depending on shape of particles, capping agent, and heat-treatment. This is related to the non-radiative rate possessed by the material. Here, we observed the high quenching of the luminescence intensity of Eu3+ doped GdPO4 prepared in water (H2O) medium. On the contrary, in ethylene glycol (EG) medium, it shows high luminescence. Luminescence intensity is recovered when Eu3+ doped GdPO4 nanorods prepared in H2O medium is heated above 700 degrees C. This transforms hexagonal to monoclinic structure following the removal of water. Luminescence intensity is enhanced by changing the medium from H2O to D2O and also if core-shell formation occurs. Also, we found significant variation in bending and stretching vibrations of O-H and microstructure in this material prepared in H2O and EG. Two types of O-H stretching frequencies are observed at 3450 and 3520cm(-1) in H2O medium prepared sample which are assigned to the O-H having the hydrogen bonding (surface water) and the confined water, respectively. The formation of nanorods is due to the presence of water on the surface of particles or/and inside the pores of compound. The available water in the nanoparticles pores can be utilized for the efficient killing of mass cells tumor by generating reactive free radicals (H-center dot and OH center dot) through the application of laser near infrared (NIR) source and the subsequent irradiation of gamma ray. This proposed mechanism is quite different from the conventional treatment of mass cell/malignant tumor using gamma ray radiation. Sample is highly paramagnetic and it will be useful for magnetic resonance imaging contrast agent. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4731644