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1.
Nutr Cancer ; 75(1): 357-367, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36052999

RESUMEN

Head and neck cancer (HNC) patients undergoing curative radiotherapy (RT) are at risk of malnutrition due to disease process as well as effects of therapy. Identifying the nutritional status of these patients at the earliest, helps to introduce adequate and timely interventions that can improve compliance and outcomes of treatment. Various tools for nutritional assessment in cancer patients have been proposed. In this prospective observational study we used the Subjective Global Assessment (SGA) questionnaire in a cohort of HNC patients receiving definitive RT at a regional cancer center of North East India. Recording of data was done at baseline, at two weekly intervals during treatment, at end of radiotherapy (EORT) and at follow-up upto 6 months. We observed that despite proper nutrition counseling, our patients suffered from malnutrition throughout their course of RT, which was at its peak by EORT but gradually improved over six months of follow-up. Pain on eating and swallowing were the most debilitating symptoms which caused significant decline of nutrient intake, body fat and muscle mass among patients together with deteriorating SGA ratings. Our results will hopefully help us design better strategies for nutrition management while delivering curative (chemo)radiotherapy for HNC patients of this region- which has one of the highest incidences of HNC in the world.


Asunto(s)
Neoplasias de Cabeza y Cuello , Desnutrición , Humanos , Estado Nutricional , Evaluación Nutricional , Desnutrición/diagnóstico , Desnutrición/etiología , Desnutrición/epidemiología , Neoplasias de Cabeza y Cuello/radioterapia , Neoplasias de Cabeza y Cuello/complicaciones , Estudios Prospectivos
2.
Phys Chem Chem Phys ; 19(6): 4678-4687, 2017 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-28127600

RESUMEN

The inelastic scattering of H2O by He as a function of collision energy in the range 381 cm-1 to 763 cm-1 at an energy interval of approximately 100 cm-1 has been investigated in a crossed beam experiment using velocity map imaging. Change in collision energy was achieved by varying the collision angle between the H2O and He beam. We measured the state-to-state differential cross section (DCS) of scattered H2O products for the final rotational states JKaKc = 110, 111, 221 and 414. Rotational excitation of H2O is probed by (2 + 1) resonance enhanced multiphoton ionization (REMPI) spectroscopy. DCS measurements over a wide range of collision energies allowed us to probe the H2O-He potential energy surface (PES) with greater detail than in previous work. We found that a classical approximation of rotational rainbows can predict the collision energy dependence of the DCS. Close-coupling quantum mechanical calculations were used to produce DCS and partial cross sections. The forward-backward ratio (FBR), is introduced here to compare the experimental and theoretical DCS. Both theory and experiments suggest that an increase in the collision energy is accompanied with more forward scattering.

3.
J Phys Chem A ; 120(41): 8085-8092, 2016 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-27684586

RESUMEN

Infrared (IR) spectra of complexes between NaCl and methanol have been recorded for the first time. These complexes were formed in liquid helium nanodroplets by consecutive pick-up of NaCl and CH3OH molecules. For the smallest NaCl(CH3OH)n, complexes where n = 1-3, the IR data suggest that the lowest-energy isomer is the primary product in each case. The predominant contribution to the binding comes from ionic hydrogen bonds between the OH in each methanol molecule and the chloride ion in the NaCl, as established by the large red shift of the OH stretching bands compared with the isolated CH3OH molecule. For n ≥ 4, there is a dramatic shift from discrete vibrational bands to very broad absorption envelopes, suggesting a profound change in the structural landscape and, in particular, access to multiple low-energy isomers.

4.
J Chem Phys ; 144(12): 121103, 2016 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-27036420

RESUMEN

To explore how the ion-pair in a single salt molecule evolves with the addition of water, infrared (IR) spectra of complexes composed of NaCl and multiple water molecules have been recorded for the first time. The NaCl(H2O)n complexes were formed and probed in liquid helium nanodroplets, and IR spectra were recorded for n = 1 → 4. The spectra for n = 1, 2, and 3 are consistent with formation of the lowest energy contact-ion pair structures in which each water molecule forms a single ionic hydrogen bond to an intact Na(+)Cl(-) ion-pair. Alternative structures with hydrogen bonding between water molecules become energetically competitive for n = 4, and the IR spectrum indicates likely the coexistence of at least two isomers.

5.
J Environ Manage ; 171: 1-10, 2016 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-26866669

RESUMEN

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief. After further consultation with the experts conducting research in the area of XRD and FTIR spectrum, it has been concluded that the appropriate action for this case is the full retraction of the article from the Journal of Environmental Management. The rationale for this decision is what the journal has concluded to be the fabrication of data associated with Figure 2a in the manuscript which shows three distinct areas in the noise patters with unusual similarities to be considered as coincidental. The data presented in Figure 2a jeopardizes the quality of the manuscript and the conclusions drawn based on the data presented in Figure 2.


Asunto(s)
Bentonita/química , Colorantes/química , Violeta de Genciana/química , Contaminantes Químicos del Agua/química , Adsorción , Concentración de Iones de Hidrógeno , Cinética , Ácidos Sulfúricos/química , Suspensiones , Temperatura , Purificación del Agua/métodos
6.
Phys Rev Lett ; 114(23): 233401, 2015 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-26196800

RESUMEN

Metal atoms have proved to be sensitive probes of the properties of superfluid helium nanodroplets. To date, all experiments on the doping of helium droplets have concentrated on the attachment of metal atoms in their ground electronic states. Here we report the first examples of metal atoms in excited states becoming attached to helium nanodroplets. The atoms in question are aluminum, and they have been generated by laser ablation in a metastable quartet state, which attaches to and remains on the surface of helium droplets. Evidence for a surface location comes from electronic spectra, which consist of very narrow absorption profiles that show very small spectral shifts. Supporting ab initio calculations show there to be an energy incentive for a metastable Al atom to remain on the surface of a helium droplet rather than move to the interior. The results suggest that helium droplets may provide a method for the capture and transport of metastable excited atomic and molecular species.

7.
Phys Chem Chem Phys ; 17(21): 14145-58, 2015 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-25958859

RESUMEN

Rotationally resolved resonance enhanced multiphoton ionisation spectra of the B̃(1)E'' state of NH2D are presented and analysed. The analysis indicates a small (34.9 cm(-1)) lifting of the vibronic degeneracy of the zero point level, approximately equal in sign but opposite in magnitude to the splitting observed in NHD2 in previous work. This observation is consistent with previous measurements on systems with partial isotopic substitution subject to a mild Jahn-Teller effect. A model is developed to calculate the splitting induced by asymmetric isotopic substitution of a degenerate electronic state, based on a harmonic force field with linear and quadratic Jahn-Teller terms added. The force field is developed in internal co-ordinates to allow the same parameters to be used to calculate the pattern of vibronic levels for all four isotopologues. The lifting of the degeneracy of the zero point level on asymmetric substitution comes from the quadratic Jahn-Teller effect; the linear term does not lift the degeneracy.

8.
J Phys Chem A ; 119(50): 12526-37, 2015 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-26473516

RESUMEN

A joint theoretical and experimental study of state-to-state rotationally inelastic polarization dependent differential cross sections (PDDCSs) for CO (v = 0, j = 0, 1, 2) molecules colliding with helium is reported for collision energies of 513 and 840 cm(-1). In a crossed molecular beam experiment, velocity map imaging (VMI) with state-selective detection by (2 + 1) and (1 + 1') resonance enhanced multiphoton ionization (REMPI) is used to probe rotational excitation of CO due to scattering. By taking account of the known fractions of the j = 0, 1, and 2 states of CO in the rotationally cold molecular beam (Trot ≈ 3 K), close-coupling theory based on high-quality ab initio potential energy surfaces for the CO-He interaction is used to simulate the differential cross sections for the mixed initial states. With polarization-sensitive 1 + 1' REMPI detection and a direct analysis procedure described by Suits et al. ( J. Phys, Chem. A 2015 , 119 , 5925 ), alignment moments are extracted from the images and the latter are compared with images simulated by theory using the calculated DCS and alignment moments. In general, good agreement of theory with the experimental results is found, indicating the reliability of the experiment in reproducing state-to-state differential and polarization-dependent differential cross sections.

9.
J Chem Phys ; 142(3): 034309, 2015 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-25612711

RESUMEN

Differential cross sections (DCSs) for inelastic collisions of OH(X) with Xe have been measured at a collision energy of 483 cm(-1). The hydroxyl (OH) radicals were initially prepared in the X(2)Π3/2 (v = 0, j = 1.5, f) level using the hexapole electric field selection method. Products were detected state-selectively by [2 + 1] resonance-enhanced multiphoton ionization of OH, combined with velocity-map imaging. Integral cross sections in OH(X) + Xe at a collision energy of 490 cm(-1) were also measured by laser-induced fluorescence. The results are compared with exact close-coupling quantum mechanical scattering calculations on the only available ab initio potential energy surface (PES). The agreement between experimental and theoretical results is generally very satisfactory. This highlights the ability of such measurements to test the available PES for such a benchmark open-shell system. The agreement between experiment and theory for DCSs is less satisfactory at low scattering angles, and possible reasons for this disagreement are discussed. Finally, theoretical calculations of OH(X) + He DCSs have been obtained at various collision energies and are compared with those of OH(X) + Xe. The role of the reduced mass in the DCSs and partial cross sections is also examined.

11.
Phys Chem Chem Phys ; 16(2): 477-88, 2014 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-24084665

RESUMEN

State-to-state differential cross sections are reported for rotationally inelastic scattering of fully state-selected ND3 (j(k)(±) = 1(1)(-)) with He. Experimental measurements are compared with full close-coupling quantum-mechanical scattering calculations that used an ab initio potential energy surface. Results are presented for final states up to j'(k')(±) = 7(7)(-) at a mean collision energy of 430 cm(-1). For selected final quantum states, the effect of collision energy on the differential cross sections is also explored in the range 230-720 cm(-1). For the experimental studies, a hexapole electrostatic lens was used for the j(k)(±) state-selection of ND3 molecules in their electronic and vibrational ground states in a molecular beam. This state-selected molecular beam was then crossed with a beam of He atoms. The velocities of inelastically scattered ND3 molecules in single j'(k')(±) states were obtained by velocity map imaging, and converted to differential cross sections in the centre-of-mass frame by density-to-flux transformation. The close-coupling calculations reproduce well the measured angular distributions. For small changes in the rotational angular momentum quantum number (j), the ND3 is predominantly forward scattered, but the scattering shifts to the sideways and backward directions as Δj increases. For scattering into a given j'(k')(±) state, cross-sections for collisions that conserve the ± symmetry associated with the ND3 inversion vibration are larger and generally more forward scattered than the corresponding symmetry-changing processes.

12.
Indian J Otolaryngol Head Neck Surg ; 76(1): 1425-1429, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38440617

RESUMEN

Head and neck oncology represents a complex and challenging field, encompassing the diagnosis, treatment and management of various malignancies affecting the intricate anatomical structures of the head and neck region. With advancements in artificial intelligence (AI), chatbot applications have emerged as a promising tool to revolutionize the field of Head and Neck oncology. ChatGPT is a cutting-edge language model developed by OpenAI that can help the oncologist in the clinic in scheduling appointments, establishing a clinical diagnosis, making a treatment plan and follow-up. ChatGPT also plays an essential role in telemedicine consultations, medical documentation, scientific writing and research. ChatGPT carries its inherent drawbacks too. ChatGPT raises significant ethical concerns related to authorship, accountability, transparency, bias, and the potential for misinformation. ChatGPT's training data is limited to September 2021; thus, regular updates are required to keep pace with the rapidly evolving medical research and advancements. Therefore, a judicial approach to using ChatGPT is of utmost importance. Head and Neck Oncologists can reap the maximum benefit of this technology in terms of patient care, education and research to improve clinical outcomes.

13.
Indian J Surg Oncol ; 15(2): 241-249, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38741641

RESUMEN

Preoperative chemoradiotherapy is a standard treatment for patients with locally advanced, resectable esophageal cancer. The treatment completion rates impact the survival outcomes (Eyck et al J Clin Oncol 39(18):1995-2004, 2021). Thus, we aimed to estimate the effect of neoadjuvant chemoradiotherapy (NACRT) in terms of treatment completion rates and survival in this subset of patients and bring out the clinical outcomes in that context. This was a retrospective study done at a tertiary cancer center in North-East India. The study period was from 1 January 2018 to 31 December 2021. We included patients diagnosed with locally advanced and resectable esophageal cancer (cT2-3NanyM0) involving the middle and/or lower thoracic esophagus and who were planned for trimodality treatment in the Joint Tumor Board. Out of the 82 patients who were planned for trimodality treatment, all were squamous cell carcinomas. We found that 54.9% of patients completed the entire trimodality treatment. The median age was 56 years (range 34 to 73 years). The male to female ratio was 59:23. Adverse events, of any grade, were seen in 76% of patients who received NACRT. Fatigue (66%) was the most common toxicity. The common hematologic toxicities were neutropenia and anemia (7.3% each). A total of 45 patients (54.9%) were able to complete all the three modalities of treatment. Transthoracic esophagectomy was the preferred approach (84.4%). The site of anastomosis was in the neck of all the patients. Anastomotic leak was seen in 17.7% of patients. Postoperative pulmonary and cardiac complications occurred in 31.1% and 8.9% of patients respectively. The 30-day mortality was 6.7% (three deaths). A pathological complete response was seen in 35.6% among patients who underwent an esophagectomy. R0 resection was achieved in 93.3% of patients. The median overall survival and disease-free survival were 19 months and 17 months respectively. The completion rate of trimodality treatment in the real-world scenario was found to be low in our study, the reasons for which need to be identified and effectively resolved. Oncological outcomes were similar to the published literature.

14.
J Cancer Res Ther ; 20(3): 763-769, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-39023580

RESUMEN

PURPOSE: The current study aims to compare the split x-jaw planning technique of volumetric modulated arc radiotherapy (VMAT) with the traditional open and limited jaw techniques of VAMT in nasopharyngeal carcinoma treatment. The multi-leaf collimators on the varian linear accelerator move on a carriage with a maximum leaf span of 15 cm. Therefore, treatment of larger planning target volumes, such as in nasopharyngeal cancer with traditional open and limited jaw technique, yields compromised dose distribution. METHOD: Computed tomography data sets of 10 nasopharynx cancer patients were enrolled for the study. For each case, three separate treatment plans were generated viz. open, limited, and split x-jaw planning techniques with similar planning objectives. Only PTVs requiring a field size larger than 18 cm in the x-jaw position were considered. RESULTS: Comparable results were obtained regarding organs at risk (OAR) sparing in all the techniques. The target dose coverage with split x-jaw VMAT was superior to both open and limited jaw planning techniques, with a statistically significant difference in the intermediate dose planning target volumes (PTVs) (PTV59.4), P < 0.05. However, the split technique's dose to the spinal cord and larynx was significantly lower (P < 0.05). CONCLUSION: The split x-jaw planning technique of VMAT can be adapted for larger PTVs requiring an x-jaw of more than 15 cm. The only concern with this technique is the increased MU.


Asunto(s)
Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas , Órganos en Riesgo , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador , Radioterapia de Intensidad Modulada , Humanos , Radioterapia de Intensidad Modulada/métodos , Neoplasias Nasofaríngeas/radioterapia , Planificación de la Radioterapia Asistida por Computador/métodos , Órganos en Riesgo/efectos de la radiación , Carcinoma Nasofaríngeo/radioterapia , Radiometría/métodos , Tomografía Computarizada por Rayos X/métodos , Masculino
15.
Phys Chem Chem Phys ; 15(17): 6390-9, 2013 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-23525370

RESUMEN

Rotational analysis of the (2 + 1) resonance enhanced multiphoton ionization (REMPI) spectrum of the B[combining tilde](1)E'' Rydberg state of the ammonia isotopologue NHD2 is reported. While the electronic degeneracy is lifted in NHD2 the splitting is small enough that interactions between the two states must be considered, particularly to model the intensity of the transitions. A simple model is developed to account for these interactions, relating them to terms present in the symmetric isotopologues. Spectroscopic parameters for the zero point and (ν2' = 1-6) vibrational levels of the B (1)E'' state have been derived using this model and the spectra are accurately simulated for the first time using the pgopher program. The current work provides the basis for on-going velocity map imaging studies of rotational energy transfer in the mixed isotopologues of ammonia.

16.
J Chem Phys ; 138(2): 024314, 2013 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-23320690

RESUMEN

We present state-to-state differential cross sections (DCSs) for rotationally inelastic scattering of HDO by normal- and para-H(2) at collision energies of 580 cm(-1) and 440 cm(-1). (2+1) resonance enhanced multiphoton ionization is used to detect rotationally cold HDO molecules before collision and as scattering products, which occupy higher rotational states due to collision with H(2). Relative integral cross sections of HDO are obtained by integrating its DCSs measured at the same experimental conditions. Experimental and theoretical DCSs of HDO scattered by normal- and para-H(2) are in good agreement in 30°-180° range of scattering angles. This partial agreement shows the accuracy of the recently tested potential of H(2)O-H(2), but now by using a completely different set of rotational transitions that are (unlike in H(2)O), not forbidden by nuclear spin restrictions. Similar results are presented for D(2)O scattered by normal-H(2) at collision energy of 584 cm(-1). The agreement between experiment and theory is, however, less good for forward scattering of HDO/D(2)O. A critical analysis of this discrepancy is presented.

17.
J Med Phys ; 48(4): 398-401, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38223790

RESUMEN

This brief communication article examines the constraints posed by the Varian linear accelerator machine's volumetric-modulated arc therapy (VMAT) due to the maximum extent of the multileaf collimator (MLC) in the x-jaw direction. The MLC leaves within this machine are capable of extending up to 15 cm in the x-jaw direction. However, when VMAT is employed with excessive extension, modulation level decreases, leading to compromised target dose distribution, and the protection of critical organs. The existing VMAT techniques involve open and limited x-jaw approaches, but these methods present avenues for enhancement. One innovative approach is the split x-jaw planning technique, which involves segmenting the open field into two distinct fields with some overlap. This strategy yields four treatment arcs that comprehensively cover the planning target volume (PTV). Enhancing modulation and conformity can be achieved by restricting each field's size to 15 cm. Consequently, this technique demonstrates improved target dose distributions, heightened plan conformity, and more effective sparing of organs at risk compared to the limited and open methodologies. Initial dosimetric studies suggest that the split X-jaw technique holds promise as a superior planning solution for larger PTVs that exceed the MLC's maximum x-jaw extent.

18.
Indian J Otolaryngol Head Neck Surg ; 75(4): 3519-3529, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37974841

RESUMEN

Purpose: The extranodal extension (ENE) in head and neck squamous cell carcinoma (HNSCC) is a potential poor prognostic factor. Clinical ENE (cENE) was incorporated in the HNSCC staging system in the 8th edition of AJCC. There is not much evidence to support the treatment of HNSCC with cN3b with radiotherapy in radical intent. This study aims to assess the treatment outcome in patients of HNSCC with cN3b disease treated with definitive radiotherapy. Method: Forty-five HNSCC patients with cN3b disease treated with definitive radiotherapy with or without concurrent chemotherapy between January 2018 to December 2018 were retrospectively evaluated. Results: The median age of the study patients was 60 years (40-75years). Only 35 patients (77.8%) could complete the prescribed course of treatment, and the leading common cause of non-completion was treatment-related toxicities. After a median follow-up period of 9.3 months (range 2-33), the median OS and PFS were 22.6 months and 7.2 months, respectively. Fourteen patients (31.1%) in our study developed grade III/IV mucositis, and 11 (24.4%) developed severe grade III/IV dermatitis. The locoregional failure constituted 24 patients (53.3%). Conclusion: The treatment outcome of HNSCC with cN3b disease is inferior. A personalized and subjective approach should be undertaken before choosing radiotherapy with a radical intent in this group of patients.

19.
J Cancer Res Ther ; 19(Suppl 2): S466-S471, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-38384006

RESUMEN

ABSTRACTS: Lymphoepithelial carcinoma (LEC) of the larynx is a rare tumor comprising 0.2% of all laryngeal neoplasms. To our knowledge, less than 50 cases of LEC of the larynx are reported in the literature. The lack of specific guidelines leads to uncertainty on this rare entity's diagnosis, treatment, and follow-up. The association of Epstein-Barr virus as a predisposing factor of LEC has been proposed in a few reports. Although the occurrence of LEC in the larynx is infrequent, it is essential to differentiate it from squamous cell carcinoma. Immunohistochemistry should be performed to demonstrate cytokeratin expression. It is a very aggressive tumor with high metastatic potential; however, it is hard to comment on the disease outcome of LEC of the larynx because only case reports are available in the literature. Here, we report a case of LEC of the larynx (CK +ve, CD 45 -ve, and EBER-ISH -ve) in a 49-year-old male. Initially, the patient was planned for surgery but defaulted. He reported back after 4 months, and there was clinicoradiological disease progression. Because of the unresectable status and poor general condition, he received palliative radiotherapy only. Additionally, we have conducted a pooled analysis of the individual cases of LEC of larynx available in the literature to understand the clinical behavior to optimize the treatment of these patients.


Asunto(s)
Carcinoma de Células Grandes , Carcinoma de Células Escamosas , Infecciones por Virus de Epstein-Barr , Laringe , Masculino , Humanos , Persona de Mediana Edad , Herpesvirus Humano 4 , Carcinoma de Células Escamosas/patología , Laringe/patología
20.
J Cancer Res Ther ; 19(Suppl 2): S904-S908, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-38384076

RESUMEN

ABSTRACT: Germ cell tumor of the central nervous system (CNS) is an infrequent entity consisting of only 0.2%-1.7% of all primary CNS tumors. The pineal gland is the commonest location of CNS germinoma. Traditionally, radiotherapy alone has been used to treat localized pineal germinoma, which has delivered a very high cure rate. Spinal drop metastases from pineal germinoma can develop after a long time from diagnosis and primary treatment. Currently, craniospinal irradiation is the standard of care in metastatic pineal germinoma with spinal drop metastases along with systemic chemotherapy. Very few cases of pineal germinoma with spinal drop metastases have been published in the literature. We report a pineal gland germinoma case with spinal drop metastases in an 18-year-old boy and reviewed the published literature.


Asunto(s)
Neoplasias Encefálicas , Germinoma , Neoplasias de Células Germinales y Embrionarias , Glándula Pineal , Masculino , Humanos , Adolescente , Glándula Pineal/patología , Germinoma/diagnóstico , Germinoma/terapia , Neoplasias Encefálicas/patología
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