35 research outputs found

    Anyon dynamics in field-driven phases of the anisotropic Kitaev model

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    The Kitaev model on a honeycomb lattice with bond-dependent Ising interactions offers an exactly solvable model of a quantum spin liquid (QSL) with gapped Z2Z_2 fluxes and gapless linearly dispersing Majorana fermions in the isotropic limit (Kx=Ky=KzK_x=K_y=K_z). We explore the phase diagram along two axes, an external magnetic field, hh, applied out-of-plane of the honeycomb, and anisotropic interactions, KzK_z larger than the other two. For Kz/K≫2K_z/K\gg 2 and h=0h=0, the matter Majorana fermions have the largest gap, and the system is described by a gapped Z2Z_2 Toric code in which the Z2Z_2 fluxes form the low energy bosonic Ising electric (e) and magnetic (m) charges along with their fermionic bound state Ο΅=eΓ—m\epsilon=e\times m. In this regime, we find that a small out-of-plane magnetic field creates Ο΅\epsilon fermions that disperse in fixed one-dimensional directions before the transition to a valence bond solid phase, providing a direct dynamical signature of low energy Z2Z_2 Abelian flux excitations separated from the Majorana sector. At lower KzK_z in the center of the Abelian phase, in a regime we dub the primordial fractionalized (PF) regime, the field generates a hybridization between the Ο΅\epsilon fermions and the Majorana matter fermions, resulting in a ψ\psi fermion. All the other phases in the field-anisotropy plane are naturally obtained from this primordial soup. We show that in the Z2Z_2 Abelian phase, including the PF regime, the dynamical structure factors of local spin flip operators reveal distinct peaks that can be identified as arising from different anyonic excitations. We present in detail their signatures in energy and momentum and propose their identification by inelastic light scattering or inelastic polarized neutron scattering as ``smoking gun" signatures of fractionalization in the QSL phase.Comment: 16 pages, 6 figures, 1 tabl

    Metronomic adjuvant chemotherapy evaluation in locally advanced head and neck cancers post radical chemoradiation – a randomised trial

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    Background: Locally advanced head and neck cancers treated with radical chemoradiation have unsatisfactory outcomes. Oral metronomic chemotherapy improves outcomes in comparison to maximum tolerated dose chemotherapy in the palliative setting. Limited evidence suggests that it may do so in an adjuvant setting. Hence this randomized study was conducted.Β Methods: Patients of head and neck (HN) cancer with primary in oropharynx, larynx or hypopharynx, with PS 0–2 post radical chemoradiation with documented complete response were randomized 1:1 to either observation or oral metronomic adjuvant chemotherapy (MAC) for 18 months. MAC consisted of weekly oral methotrexate (15 mg/m2) and celecoxib (200 mg PO BD). The primary endpoint was OS and the overall sample size was 1038. The study had 3 planned interim analyses for efficacy and futility. Trial registration- Clinical Trials Registry- India (CTRI): CTRI/2016/09/007315 [Registered on: 28/09/2016] Trial Registered Prospectively.Β Findings: 137 patients were recruited and an interim analysis was done. The 3 year PFS was 68.7% (95% CI 55.1–79.0) versus 60.8% (95% CI 47.9–71.4) in the observation and metronomic arm respectively (P value = 0.230). The hazard ratio was 1.42 (95% CI 0.80–2.51; P value = 0.231). The 3 year OS was 79.4% (95% CI 66.3–87.9) versus 62.4% (95% CI 49.5–72.8) in the observation and metronomic arm respectively (P value = 0.047). The hazard ratio was 1.83 (95% CI 1.0–3.36; P value = 0.051).Β Interpretation: In this phase 3 randomized study, oral metronomic combinations of weekly methotrexate and daily celecoxib failed to improve the PFS or OS. Hence observation post-complete response post radical chemoradiation remains the standard of care.Β Funding: ICON funded this study.</p

    Metronomic adjuvant chemotherapy evaluation in locally advanced head and neck cancers post radical chemoradiation – a randomised trial

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    Background: Locally advanced head and neck cancers treated with radical chemoradiation have unsatisfactory outcomes. Oral metronomic chemotherapy improves outcomes in comparison to maximum tolerated dose chemotherapy in the palliative setting. Limited evidence suggests that it may do so in an adjuvant setting. Hence this randomized study was conducted.Β Methods: Patients of head and neck (HN) cancer with primary in oropharynx, larynx or hypopharynx, with PS 0–2 post radical chemoradiation with documented complete response were randomized 1:1 to either observation or oral metronomic adjuvant chemotherapy (MAC) for 18 months. MAC consisted of weekly oral methotrexate (15 mg/m2) and celecoxib (200 mg PO BD). The primary endpoint was OS and the overall sample size was 1038. The study had 3 planned interim analyses for efficacy and futility. Trial registration- Clinical Trials Registry- India (CTRI): CTRI/2016/09/007315 [Registered on: 28/09/2016] Trial Registered Prospectively.Β Findings: 137 patients were recruited and an interim analysis was done. The 3 year PFS was 68.7% (95% CI 55.1–79.0) versus 60.8% (95% CI 47.9–71.4) in the observation and metronomic arm respectively (P value = 0.230). The hazard ratio was 1.42 (95% CI 0.80–2.51; P value = 0.231). The 3 year OS was 79.4% (95% CI 66.3–87.9) versus 62.4% (95% CI 49.5–72.8) in the observation and metronomic arm respectively (P value = 0.047). The hazard ratio was 1.83 (95% CI 1.0–3.36; P value = 0.051).Β Interpretation: In this phase 3 randomized study, oral metronomic combinations of weekly methotrexate and daily celecoxib failed to improve the PFS or OS. Hence observation post-complete response post radical chemoradiation remains the standard of care.Β Funding: ICON funded this study.</p

    Can Administration of Potentized Homeopathic Remedy, Arsenicum Album, Alter Antinuclear Antibody (ANA) Titer in People Living in High-Risk Arsenic Contaminated Areas? I. A Correlation with Certain Hematological Parameters

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    To examine whether elevated antinuclear antibody (ANA) titers reported in random human population of arsenic contaminated villages can be reverted to the normal range by administration of a potentized homeopathic drug, Arsenicum album, randomly selected volunteers in two arsenic contaminated villages and one arsenic-free village in West Bengal (India) were periodically tested for their ANA titer as well as various blood parameters in two types of experiments: β€˜placebo-controlled double blind’ experiment for shorter duration and β€˜uncontrolled verum fed experiment’ for longer duration. Positive modulation of ANA titer was observed along with changes in certain relevant hematological parameters, namely total count of red blood cells and white blood cells, packed cell volume, hemoglobin content, erythrocyte sedimentation rate and blood sugar level, mostly within 2 months of drug administration. Thus, Arsenicum album appears to have great potential for ameliorating arsenic induced elevated ANA titer and other hematological toxicities

    Can Homeopathic Arsenic Remedy Combat Arsenic Poisoning in Humans Exposed to Groundwater Arsenic Contamination?: A Preliminary Report on First Human Trial

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    Groundwater arsenic (As) has affected millions of people globally distributed over 20 countries. In parts of West Bengal (India) and Bangladesh alone, over 100 million people are at risk, but supply of As-free water is grossly inadequate. Attempts to remove As by using orthodox medicines have mostly been unsuccessful. A potentized homeopathic remedy, Arsenicum Album-30, was administered to a group of As affected people and thereafter the As contents in their urine and blood were periodically determined. The activities of various toxicity marker enzymes and compounds in the blood, namely aspartate amino transferase, alanine amino transferase, acid phosphatase, alkaline phosphatase, lipid peroxidation and reduced glutathione, were also periodically monitored up to 3 months. The results are highly encouraging and suggest that the drug can alleviate As poisoning in humans

    Amelioration of Carcinogen-Induced Toxicity in Mice by Administration of a Potentized Homeopathic Drug, Natrum Sulphuricum 200

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    To examine if a potentized homeopathic drug, Natrum Sulphuricum 200 (Nat Sulph-200) has protective potentials against hepatocarcinogenesis, liver tumors were induced in mice through chronic feeding of P-dimethylaminoazobenzene (p-DAB; initiator of hepatocarcinogenesis) and phenobarbital (PB; promoter). Mice were divided into five sub-groups: fed normal low protein diet (Gr. I, normal control); fed normal low protein plus alcohol-200 (vehicle of the homeopathic remedy) (Gr. II); fed diet mixed with 0.06% p-DAB plus 0.05% PB (Gr. III); fed diet and carcinogens like Gr.III, plus alcohol 200 (positive control for drug fed mice) (Gr. IV) and fed diet and carcinogens like Gr. III, plus Natrum Sulphuiricum-200 (Gr. V; drug fed). Mice were sacrificed at day 7, 15, 30, 60, 90 and day 120 for study of cytogenetical endpoints like chromosome aberrations (CA), micronuclei (MN), mitotic index (MI) and sperm head anomaly (SHA) and biochemical toxicity parameters like aspartate amino transferase (AST), alanine amino transferase (ALT), acid (AcP) and alkaline (AlkP) phosphatases, lipid peroxidation (LPO) and reduced glutathione (GSH) content. Less number of liver tumors were observed in Gr. V (drug fed) mice. Administration of Nat Sulph 200 reduced genomic damage, activities of AcP, AlkP, AST, ALT, LPO and increased GSH content. Therefore, independent replication of the study by others is encouraged

    RMAC study:A randomized study for evaluation of metronomic adjuvant chemotherapy in recurrent head and neck cancers post salvage surgical resection in those who are ineligible for re-irradiation

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    Background: Adjuvant re-chemoradiation after salvage surgery improves disease-free survival in recurrent head and neck cancer. However, most patients are ineligible for re-irradiation and are kept on observation. We investigated the efficacy of metronomic adjuvant chemotherapy (MAC) in this group of patients compared to observation. Methods: This was a randomized integrated phase II/III clinical trial. Adults with recurrent head and neck cancer, who had undergone salvage surgery, but were ineligible for adjuvant re-irradiation were randomized in a 1:1 ratio to either MAC arm or observation. MAC consisted of weekly oral methotrexate (at a dose of 15 mg per square meter of body surface area) and celecoxib (at a dose of 200 mg orally twice daily) for 6 months. The primary endpoint of phase 2 was disease-free survival (DFS) while that of phase 3 was overall survival (OS). For phase 2, to detect an improvement in the hazard ratio (HR) 0.67 with MAC, with a type 1 error of 10% (1-sided), type 2 error of 30%, 105 patients were required. While for phase 3, with a target HR of 0.77, with a type 1 error of 5%, type 2 error of 20%, 318 patients were required. Here we report the results of phase 2 part of the study. Results: At a median follow up of 30.2 months (95% confidence interval (CI), 25.3 to 35.1) the 1 year and 2-year DFS were 57.4% (95% CI, 42.8–69.5) and 37.6% (95% CI, 24.1–51) in MAC arm whereas the corresponding numbers were 62.3% (95% CI, 47.8 to 73.8) and 54.2%(95% CI, 39.8 to 66.5) in observation arm, respectively (hazard ratio for progression, 1.45; 95% CI, 0.87 to 2.47; P = 0.15). In the MAC arm, the 1 and 2 year OS was 78.7% (95% CI, 64.9 to 87.6) and 48% (95% CI, 34.1 to 62).The corresponding figures in the observation arm were 79.2% (95% CI, 65.7 to 87.9) and 65.5% (95% CI, 50.9 to 76.7) (hazard ratio for death, 1.7, 95% CI, 0.94 to 3.08; P = 0.08). Conclusion: The adjuvant 6-month metronomic schedule was ineffective in improving outcomes in recurrent head and neck cancers post salvage surgery who are ineligible for re-radiation. Trial registration. Clinical trial registry of India (CTRI)- CTRI/2016/04/006872 [Registered on 26/4/2016] Β© 2022 Elsevier Lt

    RMAC study:A randomized study for evaluation of metronomic adjuvant chemotherapy in recurrent head and neck cancers post salvage surgical resection in those who are ineligible for re-irradiation

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    Background: Adjuvant re-chemoradiation after salvage surgery improves disease-free survival in recurrent head and neck cancer. However, most patients are ineligible for re-irradiation and are kept on observation. We investigated the efficacy of metronomic adjuvant chemotherapy (MAC) in this group of patients compared to observation. Methods: This was a randomized integrated phase II/III clinical trial. Adults with recurrent head and neck cancer, who had undergone salvage surgery, but were ineligible for adjuvant re-irradiation were randomized in a 1:1 ratio to either MAC arm or observation. MAC consisted of weekly oral methotrexate (at a dose of 15 mg per square meter of body surface area) and celecoxib (at a dose of 200 mg orally twice daily) for 6 months. The primary endpoint of phase 2 was disease-free survival (DFS) while that of phase 3 was overall survival (OS). For phase 2, to detect an improvement in the hazard ratio (HR) 0.67 with MAC, with a type 1 error of 10% (1-sided), type 2 error of 30%, 105 patients were required. While for phase 3, with a target HR of 0.77, with a type 1 error of 5%, type 2 error of 20%, 318 patients were required. Here we report the results of phase 2 part of the study. Results: At a median follow up of 30.2 months (95% confidence interval (CI), 25.3 to 35.1) the 1 year and 2-year DFS were 57.4% (95% CI, 42.8–69.5) and 37.6% (95% CI, 24.1–51) in MAC arm whereas the corresponding numbers were 62.3% (95% CI, 47.8 to 73.8) and 54.2%(95% CI, 39.8 to 66.5) in observation arm, respectively (hazard ratio for progression, 1.45; 95% CI, 0.87 to 2.47; P = 0.15). In the MAC arm, the 1 and 2 year OS was 78.7% (95% CI, 64.9 to 87.6) and 48% (95% CI, 34.1 to 62).The corresponding figures in the observation arm were 79.2% (95% CI, 65.7 to 87.9) and 65.5% (95% CI, 50.9 to 76.7) (hazard ratio for death, 1.7, 95% CI, 0.94 to 3.08; P = 0.08). Conclusion: The adjuvant 6-month metronomic schedule was ineffective in improving outcomes in recurrent head and neck cancers post salvage surgery who are ineligible for re-radiation. Trial registration. Clinical trial registry of India (CTRI)- CTRI/2016/04/006872 [Registered on 26/4/2016] Β© 2022 Elsevier Lt

    Impact of endocrine disrupting chemicals (EDCs) on the predisposition of cancer and polycystic ovary syndrome (PCOS): A Note

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    Endocrine Disrupting Chemicals (EDCs) or Endocrine Disruptors are unique assemblage or cluster of emerging pollutants as they affect the synthesis, release and transport of hormones. EDCs have been associated with a diverse array of health issues and diseases.&nbsp;EDCs can alter the endocrine system and are involved in carcinogenesis and inducing poly-cystic ovary syndrome (PCOS). The objective of this article is to furnish an outline of research on environmental aspects of EDCs and their effects on human health specially on cancer and PCOS based on evidence from animal and human studies. EDCs include natural compounds such as phytoestrogens and various synthetic chemicals which are utilized by the chemical, agriculture, cosmetic and food industries. Several EDCs may work as carcinogens and causes initiation and advancement of cancer. Uterine and ovarian cancers of female have been associated with exposure to EDC. Bisphenol-A (BPA), an EDC which is found in plastic bottles, household materials, canned food, waste water, beverage containers and thermal paper, can increase risk of breast cancer. Even low levels of BPA exposure may poses threat of prostate cancer in men.&nbsp;Testicular cancer and&nbsp;thyroid cancer&nbsp;could be influenced by EDCs. Comprehensive studies have been conducted by many researchers in the light of toxicity pattern of EDC that render interpretation of impact of EDCs on development of cancer and PCOS inducing capacity in female reproductive system. Keywords: Endocrine disrupting chemicals; EDC; Cancer; Endocrine Disruptor, Poly-Cystic Ovary Syndrome; PCO

    Homeopathic drugs Natrum sulphuricum and Carcinosin prevent azo dye-induced hepatocarcinogenesis in mice

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    307-318The study was undertaken to examine whether Carcinosin-200 (Car-200) could provide additional ameliorative effect, if used intermittently with Natrum sulphuricum-30 (Nat Sulph-30) against hepatocarcinogenesis induced by chronic feeding of p-dimethylaminoazobenzene (p-DAB) and phenobarbital (PB) in mice (Mus musculus). Mice were randomly divided into seven sub-groups: (i) normal untreated; (ii) normal + succussed alcohol; (iii) p-DAB (0.06%) + PB (0.05%); (iv) p-DAB + PB + succussed alcohol, (v) p-DAB + PB + Nat Sulph-30, (vi) p-DAB + PB + Car-200, and (vii) p-DAB + PB + Nat Sulph-30 + Car-200. They were sacrificed at 30, 60, 90 and 120 days for assessment of genotoxicity through cytogenetical end-points like chromosome aberrations, micronuclei, mitotic index and sperm head anomaly and cytotoxicity through assay of widely accepted biomarkers and pathophysiological parameters. Additionally, electron microscopic studies and gelatin zymography for matrix metalloproteinases (MMPs) were conducted in liver at 90 and 120 days. Results showed that administration of Nat Sulph-30 alone and in combination with Car-200 reduced the liver tumors with positive ultra-structural changes and in MMPs expression, genotoxic parameters, lipid peroxidation, -glutamyl transferase, lactate dehydrogenase, blood glucose, bilirubin, creatinine, urea and increased GSH, glucose-6-phosphate dehydrogenase, superoxide dismutase, catalase, glutathione reductase activities and hemoglobin, cholesterol, and albumin levels. Thus, intermittent use of Car-200 along with Nat Sulph-30 yielded additional benefit against genotoxicity, cytotoxicity, hepatotoxicity and oxidative stress induced by the carcinogens during hepatocarcinogenesis
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