Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 56
Filtrar
1.
J Phys Condens Matter ; 36(32)2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38697211

RESUMO

Magnetic and topological properties along with quantum correlations in terms of several entanglement measures have been investigated for an antiferromagnetic (AFM) spin-1/2 XY model in the presence of transverse magnetic field and XZX-YZY type of three-spin interactions. Symmetries of the spin Hamiltonian have been identified. Under the Jordan-Wigner transformation, the spin Hamiltonian converted into spinless superconducting model with nearest neighbor (NN) hopping and Cooper pairing terms in addition to next NN Cooper pairing potential. Long range AFM order has been studied in terms of staggered spin-spin correlation functions, while the topological orders have been characterized by winding numbers. Magnetic and topological phase diagrams have been prepared. Faithful coexistence of magnetic and topological superconducting phases is found in the entire parameter regime. Boundaries of various quantum phases have been marked and positions of bicritical points have been identified.

2.
Ophthalmol Ther ; 13(5): 1369-1382, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38530568

RESUMO

INTRODUCTION: The study aimed to evaluate comparability in terms of efficacy, safety and immunogenicity of Sun's ranibizumab biosimilar with reference ranibizumab in patients with neovascular age-related macular degeneration (nAMD). METHODS: This prospective, randomised, double-blind, two-group, parallel-arm, multicentre, phase 3 comparative study included patients with nAMD ≥ 50 years, randomised (in a 2:1 ratio) in a double-blind manner to receive 0.5 mg (0.05 mL) intravitreal injection of either Sun's ranibizumab or reference ranibizumab in the study eye every 4 weeks until week 16 (total of four doses). RESULTS: Primary endpoint results demonstrated equivalence in the proportion of patients who lost fewer than 15 letters from baseline best-corrected visual acuity (BCVA) to the end of week 16 (99% of patients in Sun's ranibizumab and 100% in reference ranibizumab; p > 0.9999), with the proportional difference (90% confidence interval) at -1% (-2.51, +0.61) lying within a pre-specified equivalence margin. Visual acuity improved by 15 or more letters in 43% of Sun's ranibizumab group and 37% of the reference ranibizumab group (p = 0.4267). The mean increase in BCVA was 15.7 letters in Sun's ranibizumab group and 14.6 letters in the reference ranibizumab group (p < 0.001 within both groups and p = 0.5275 between groups). The mean change in central macular thickness was comparable between groups (p = 0.7946). Anti-ranibizumab antibodies were found in one patient of the reference ranibizumab group, while neutralising antibodies were not found in any patients. Both products were well tolerated. CONCLUSION: Sun's ranibizumab biosimilar is found to be therapeutically equivalent to reference ranibizumab in patients with nAMD. There were no additional safety or immunogenicity concerns. TRIAL REGISTRATION: CTRI/2020/09/027629, registered on 07 September 2020.

3.
Indian J Ophthalmol ; 72(3): 352-356, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38421291

RESUMO

BACKGROUND: Neovascular glaucoma (NVG) is a secondary glaucoma with a poor visual prognosis. Trabeculectomy with antifibrotic agents, glaucoma drainage devices (GDDs), and cyclo-destructive procedures are recommended in patients who are refractory to medical management. However, due to the poor success rate of conventional trabeculectomy and the higher cost of GDDs, alternative procedures need to be looked at. PURPOSE: To compare the surgical outcomes and economic aspects of a newly developed polypropylene suture bed-based modified trabeculectomy to Ahmed glaucoma valve (AGV) implantation for NVG. METHODS: It was a prospective interventional study conducted at a tertiary care center between 2018 and 2020. Consecutive patients with NVG with a minimum follow-up of 18 months were included. Surgical outcomes are mainly based on intraocular pressure (IOP) control and the cost of surgery. RESULTS: Sixty eyes were included out of which 40 (60.6%) underwent modified trabeculectomy and 20 (33.7%) underwent AGV. At the final follow-up, no significant difference (P < 0.05) was found between the surgical outcomes of both groups. The complete success rate (IOP < 21 mm Hg without antiglaucoma medications) was 60 and 65% while the qualified success rate (IOP < 21 mm Hg with antiglaucoma medications) was 30 and 25% in modified trabeculectomy and AGV groups, respectively, at final follow-up. The cost of surgery was significantly higher in the AGV group (P < 0.0001). CONCLUSION: Modified trabeculectomy as described might be a better alternative for NVG eyes.


Assuntos
Implantes para Drenagem de Glaucoma , Glaucoma Neovascular , Glaucoma , Trabeculectomia , Humanos , Glaucoma Neovascular/cirurgia , Polipropilenos , Agentes Antiglaucoma , Estudos Prospectivos , Glaucoma/cirurgia
4.
Chemistry ; 30(4): e202302849, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-37870380

RESUMO

The oxidant-controlled divergent synthesis of C-2' formyl 2H-indazoles and indazoloindazolediones has been developed through Mn(I)- catalyzed ortho C-H functionalization of 2H-indazoles with para-formaldehyde to afford C-2' hydroxymethylated 2H-indazoles and subsequently oxidation with varying the amount of DDQ in one-pot. By employing selectfluor as the oxidant instead of DDQ, this reaction exclusively provided indazolebenzoxazine derivatives. This strategy delivered unsymmetrical indazoloindazoledione and indazolobenzoxazine with varied functional group tolerance in moderate to good yields.

5.
J Phys Condens Matter ; 36(12)2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-38064744

RESUMO

Existence of nontrivial topological phases in a tight binding Haldane-like model on the depleted Lieb lattice is reported. This two-band model is formulated by considering the nearest-neighbor (NN), next-NN (NNN) and next-NNN hopping terms along with complex phase which breaks the time reversal symmetry of this semi-metallic system. Topological feature of this model is studied along with the presence of sublattice symmetry breaking staggered onsite energy. Combined effect of these two broken symmetries is found crucial for an additional transition between nontrivial and trivial phases. System exhibits two types of phase transitions, say, between two nontrivial phases and nontrivial to trivial phases. Nonzero Chern numbers, existence of Hall plateau and symmetry protected edge states confirm the presence of the nontrivial phases. This two-band system hosts four different types of phases where two are topological. Additionally topological properties of stacked bilayer of the depleted Lieb lattices is also studied with similar Haldane-like Hamiltonian. This four-band system is found to host Chern insulating phases, with higher values of Chern numbers supported by in-gap edge states.

6.
J Glob Infect Dis ; 15(2): 66-71, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37469471

RESUMO

Introduction: Significant surge of mucormycosis was reported in the Indian Subcontinent during the second wave of the COVID-19 pandemic. COVID-associated mucormycosis (CAM) was defined as the development of features of mucormycosis with prior or current history of COVID-19 infection. Rapid angioinvasion is an important characteristic of mucormycosis. Authors intended to find out the prevalence of retinal arterial occlusion and its association with vascular embolic occlusion elsewhere in the body among CAM patients in this study. Methods: This was an observational study. All consecutive-confirmed cases of mucormycosis (n = 89) and age-/gender-/risk factor-matched controls (n = 324) admitted in the designated COVID center were included in the study. All cases and controls underwent comprehensive ophthalmological, otorhinological, and neurological examinations. All necessary investigations to support the clinical diagnosis were done. Qualitative data were analyzed using the Chi-square test. Quantitative data for comparison of means between the cases and controls were done using unpaired t-test. Results: Twenty-one (23.59%) patients manifested the defined outcome of central retinal artery occlusion (CRAO). Among age-matched control, with similar diabetic status, none had developed the final outcome as defined (P < 0.05). About 90.47% of subjects with CRAO presented with no perception of light vision. Thirteen subjects (61.9%) with the final outcome developed clinical manifestations of stroke during the course of their illness with radiological evidence of watershed infarction (P = 0.001). Orbital debridement was performed in 9 (42.85%) subjects while orbital exenteration was done in 8 (38.09%) subjects. Conclusions: CRAO in CAM patients was found to have aggressive nature turning the eye blind in a very short period of time. CRAO can serve as a harbinger for subsequent development of more debilitating and life-threatening conditions such as stroke among CAM patients.

7.
Entropy (Basel) ; 25(7)2023 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-37510052

RESUMO

In view of some recent reports on global wealth inequality, where a small number (often a handful) of people own more wealth than 50% of the world's population, we explored if kinetic exchange models of markets could ever capture features where a significant fraction of wealth can concentrate in the hands of a few as the market size N approaches infinity. One existing example of such a kinetic exchange model is the Chakraborti or Yard-Sale model; in the absence of tax redistribution, etc., all wealth ultimately condenses into the hands of a single individual (for any value of N), and the market dynamics stop. With tax redistribution, etc., steady-state dynamics are shown to have remarkable applicability in many cases in our extremely unequal world. We show that another kinetic exchange model (called the Banerjee model) has intriguing intrinsic dynamics, where only ten rich traders or agents possess about 99.98% of the total wealth in the steady state (without any tax, etc., like external manipulation) for any large N value. We will discuss the statistical features of this model using Monte Carlo simulations. We will also demonstrate that if each trader has a non-zero probability f of engaging in random exchanges, then these condensations of wealth (e.g., 100% in the hand of one agent in the Chakraborti model, or about 99.98% in the hands of ten agents in the Banerjee model) disappear in the large N limit. Moreover, due to the built-in possibility of random exchange dynamics in the earlier proposed Goswami-Sen model, where the exchange probability decreases with the inverse power of the wealth difference between trading pairs, one does not see any wealth condensation phenomena. In this paper, we explore these aspects of statistics of these intriguing models.

9.
Entropy (Basel) ; 25(5)2023 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-37238490

RESUMO

Social inequalities are ubiquitous and evolve towards a universal limit. Herein, we extensively review the values of inequality measures, namely the Gini (g) index and the Kolkata (k) index, two standard measures of inequality used in the analysis of various social sectors through data analysis. The Kolkata index, denoted as k, indicates the proportion of the 'wealth' owned by (1-k) fraction of the 'people'. Our findings suggest that both the Gini index and the Kolkata index tend to converge to similar values (around g=k≈0.87, starting from the point of perfect equality, where g=0 and k=0.5) as competition increases in different social institutions, such as markets, movies, elections, universities, prize winning, battle fields, sports (Olympics), etc., under conditions of unrestricted competition (no social welfare or support mechanism). In this review, we present the concept of a generalized form of Pareto's 80/20 law (k=0.80), where the coincidence of inequality indices is observed. The observation of this coincidence is consistent with the precursor values of the g and k indices for the self-organized critical (SOC) state in self-tuned physical systems such as sand piles. These results provide quantitative support for the view that interacting socioeconomic systems can be understood within the framework of SOC, which has been hypothesized for many years. These findings suggest that the SOC model can be extended to capture the dynamics of complex socioeconomic systems and help us better understand their behavior.

10.
J Phys Condens Matter ; 35(33)2023 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-37116501

RESUMO

Simple route of engineering topological phases for any desired value of winding and Chern numbers is found in the Su-Schrieffer-Heeger (SSH) model by adding a further neighbor hopping term of varying distances. It is known that the standard SSH model yields a single topological phase with winding number,ν = 1. In this study it is shown that how one can generate topological phases with any values of winding numbers, for examples,ν=±1,±2,±3,…,in the presence of a single further neighbor term which preserves inversion, particle-hole and chiral symmetries. Quench dynamics of the topological and trivial phases are studied in the presence of a specific nonlinear term. Another version of SSH model with additional modulating nearest neighbor and next-nearest-neighbor hopping parameters was introduced before which exhibit a single topological phase characterized by Chern number,C=±1. Standard form of inversion, particle-hole and chiral symmetries are broken in this model. Here this model has been studied in the presence of several types of parametrization among which, for a special case the system is found to yield a series of phases with Chern numbers,C=±1,±2,±3,….In another parametrization, multiple crossings within the edge states energy lines are found in both trivial and topological phases. Topological phase diagrams are drawn for every case. Emergence of spurious topological phases is also reported.

11.
Indian J Ophthalmol ; 71(4): 1561-1565, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37026302

RESUMO

Purpose: In cases of eyelid malignancies requiring full thickness excisional biopsy followed by reconstruction of the created defect, the Meibomian glands are lost. Post-operative varying degrees of dry eye disease (DED) are expected in such patients. The aim was to evaluate the objective and subjective statuses of DED in cases of full thickness eyelid reconstruction following excisional biopsy because of malignancies. Methods: This was a cross-sectional pilot study. Objective and subjective dry eye parameters are assessed in cases of full thickness eyelid reconstruction following excisional biopsy because of malignancies in 37 eyes at 6 months post-operative follow-up. Analysis of variance and Chi square test were used for statistical analysis. Results: When compared with fellow eye, all the parameters were found to be statistically significant (P < 0.0). Subjective assessment of dry eye by ocular surface disease index (OSDI) scoring did not corroborate with the objective data (p 0.00). Lower eyelid reconstruction showed a minimum number of dry eye cases (P > 0.05). Conclusion: Prevalence of post-operative dry eye is more with increasing percentage of full thickness upper eyelid reconstruction. Disparity was found between objective and subjective parameters of dry eye in patients requiring varying percentages of upper eyelid reconstruction because of malignancies.


Assuntos
Síndromes do Olho Seco , Lágrimas , Humanos , Estudos Transversais , Projetos Piloto , Glândulas Tarsais/patologia , Síndromes do Olho Seco/diagnóstico , Síndromes do Olho Seco/etiologia
12.
Indian J Psychol Med ; 45(1): 38-42, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36778628

RESUMO

Background: Depression has emerged as one of the prime morbidities affecting professional and personal lives worldwide. Antidepressants are one of the mainstays of management of depressive episodes. Although antidepressants are considered a safe class of drugs, the studies examining the effects of antidepressant prescription on intraocular pressure (IOP) have shown a propensity to increase IOP, but not consistently. This study aimed to compare the changes in IOP and iridocorneal angle in drug-naïve patients with depressive episodes prescribed escitalopram or amitriptyline. Methods: Overall, 109 patients were recruited, of which 53 were prescribed amitriptyline and 56, escitalopram. A comparison of IOP and the iridocorneal angle at weeks 0, 4, and 8 was done using a two-way repeated-measures analysis of variance (two-way RM analysis of variance). Results: Patients initiated on escitalopram tended to show a higher rise in the IOP (left eye-[F = 3.27; P = 0.04]; right eye [F = 2.47; P = 0.08]). No difference was found in the iridocorneal angles in any of the four quadrants across both eyes. Conclusions: Escitalopram use had an association with an increase in IOP. While initiating patients on antidepressants, clinicians should be aware of this possibility, which can lead to ocular emergencies, and obtain a proper history of ocular morbidities.

13.
Indian J Ophthalmol ; 70(10): 3544-3549, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36190044

RESUMO

Purpose: To assess the incidence and cause of idiopathic, irreversible loss of vision ("wipe-out") in the early post-operative period after glaucoma-filtration surgery in advanced glaucoma. Methods: It was a prospective, interventional cohort study. Patients with advanced glaucoma and macular split fixation underwent either only trabeculectomy (group A) or combined phaco-emulsification with trabeculectomy (group B). The incidence and cause of visual loss, changes in intra-ocular pressure, visual acuity, and visual field indices during 2 months post surgery were assessed. Results: Thirty patients (30 eyes) were divided in two groups. No significant difference was noted between the pre-operative and post-operative mean deviations in both groups (P = 0.41, P = 0.65). Two eyes in group A and one eye in group B had visual loss of two lines or more at the end of 2 months because of cataract and choroidal detachment. None of the eyes showed "wipe-out". Conclusion: "Wipe-out" is a rare phenomenon after surgery in advanced glaucoma.


Assuntos
Glaucoma , Trabeculectomia , Estudos de Coortes , Glaucoma/complicações , Glaucoma/cirurgia , Humanos , Pressão Intraocular , Trabeculectomia/efeitos adversos , Transtornos da Visão/etiologia , Acuidade Visual
14.
RSC Adv ; 12(30): 19412-19416, 2022 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-35865587

RESUMO

Earth-abundant and water-tolerant manganese(i) catalyzed alkenylation of 2-arylindazole with alkyl and aryl alkynes through C-H bond activation is described with a unique level of E-selectivity. The reaction proceeds through the control of C3 nucleophilicity of 2-aryl indazoles. This method is applied to the late-stage functionalization of complex molecules including ethinylestradiol, norethisterone, and N-protected amino acid derivatives. The kinetic isotope studies suggest that the C-H bond activation step may not be the rate-determining step.

15.
Nonlinear Dyn ; 109(1): 47-55, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35502431

RESUMO

The global pandemic due to the outbreak of COVID-19 ravages the whole world for more than two years in which all the countries are suffering a lot since December 2019. In this article characteristics of a multi-wave SIR model have been studied which successfully explains the features of this pandemic waves in India. Origin of the multi-wave pattern in the solution of this model is explained. Stability of this model has been studied by identifying the equilibrium points as well as by finding the eigenvalues of the corresponding Jacobian matrices. In this model, a finite probability of the recovered people for becoming susceptible again is introduced which is found crucial for obtaining the oscillatory solution in other words. Which on the other hand incorporates the effect of new variants, like delta, omicron, etc in addition to the SARS-CoV-2 virus. The set of differential equations has been solved numerically in order to obtain the variation of susceptible, infected and removed populations with time. In this phenomenological study, some specific sets of parameters are chosen in order to explain the nonperiodic variation of infected population which is found necessary to capture the feature of epidemiological wave prevailing in India. The numerical estimations are compared with the actual cases along with the analytic results.

16.
J Org Chem ; 87(9): 5682-5689, 2022 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-35471944

RESUMO

An efficient, metal-free, and direct oxidative amination of aldehyde-derived hydrazones with azoles has been developed using 2,3-dichloro-5,6-dicyano-1,4-benzoquinone as an organocatalyst at ambient temperature. This protocol provides a wide range of aminated hydrazone derivatives in a step and atom economical fashion. The reaction possibly follows a radical mechanism.


Assuntos
Aldeídos , Hidrazonas , Aminação , Azóis , Catálise , Estresse Oxidativo , Temperatura
17.
Int J Ophthalmol ; 15(4): 527-532, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35450177

RESUMO

AIM: To share clinical pattern of presentation, the modalities of surgical intervention and the one month post-surgical outcome of rhino-orbito-mucormycosis (ROCM) cases. METHODS: All COVID associated mucormycosis (CAM) patients underwent comprehensive multidisciplinary examination by ophthalmologist, otorhinolaryngologist and physician. Patients with clinical and radiological evidence of orbital apex involvement were included in the study. Appropriate medical and surgical intervention were done to each patient. Patients were followed up one-month post intervention. RESULTS: Out of 89 CAM patients, 31 (34.8%) had orbital apex syndrome. Sixty-six (74.2%) of such patients had pre-existing diabetes mellitus, 18 (58%) patients had prior documented use of steroid use, and 55 (61.8%) had no light perception (LP) presenting vision. Blepharoptosis, proptosis, complete ophthalmoplegia were common clinical findings. Seventeen (19.1%) of such patients had variable amount of cavernous sinus involvement. Endoscopic debridement of paranasal sinuses and orbit with or without eyelid sparing limited orbital exenteration was done in most cases, 34 (38.2%) patients could retain vision in the affected eye. CONCLUSION: Orbital apex involvement in CAM patients occur very fast. It not only leads to loss of vision but also sacrifice of the eyeball, orbital contents and eyelids. Early diagnosis and prompt intervention can preserve life, vision and spare mutilating surgeries.

18.
Philos Trans A Math Phys Eng Sci ; 380(2224): 20210163, 2022 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-35400180

RESUMO

We report the numerical results for the steady-state income or wealth distribution [Formula: see text] and the resulting inequality measures (Gini [Formula: see text] and Kolkata [Formula: see text] indices) in the kinetic exchange models of market dynamics. We study the variations of [Formula: see text] and of the indices [Formula: see text] and [Formula: see text] with the saving propensity [Formula: see text] of the agents, with two different kinds of trade (kinetic exchange) dynamics. In the first case, the exchange occurs between randomly chosen pairs of agents and in the next, one of the agents in the chosen pair is the poorest of all and the other agent is randomly picked up from the rest of the population (where, in the steady state, a self-organized poverty level or SOPL appears). These studies have also been made for two different kinds of saving behaviours. One, where each agent has the same value of [Formula: see text] (constant over time) and the other where [Formula: see text] for each agent can take two values (0 and 1), changing randomly over a fraction of time [Formula: see text] of choosing [Formula: see text]. We find that the inequality decreases with increasing savings ([Formula: see text]); inequality indices ([Formula: see text] and [Formula: see text]) decrease and SOPL increases with increasing [Formula: see text], indicating possible applications in economic policy making. This article is part of the theme issue 'Kinetic exchange models of societies and economies'.


Assuntos
Renda , Pobreza
19.
Mol Plant Microbe Interact ; 35(2): 131-145, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34689599

RESUMO

Root nodule symbiosis (RNS) is the pillar behind sustainable agriculture and plays a pivotal role in the environmental nitrogen cycle. Most of the genetic, molecular, and cell-biological knowledge on RNS comes from model legumes that exhibit a root-hair mode of bacterial infection, in contrast to the Dalbergoid legumes exhibiting crack-entry of rhizobia. As a step toward understanding this important group of legumes, we have combined microscopic analysis and temporal transcriptome to obtain a dynamic view of plant gene expression during Arachis hypogaea (peanut) nodule development. We generated comprehensive transcriptome data by mapping the reads to A. hypogaea, and two diploid progenitor genomes. Additionally, we performed BLAST searches to identify nodule-induced yet-to-be annotated peanut genes. Comparison between peanut, Medicago truncatula, Lotus japonicus, and Glycine max showed upregulation of 61 peanut orthologs among 111 tested known RNS-related genes, indicating conservation in mechanisms of nodule development among members of the Papilionoid family. Unlike model legumes, recruitment of class 1 phytoglobin-derived symbiotic hemoglobin (SymH) in peanut indicates diversification of oxygen-scavenging mechanisms in the Papilionoid family. Finally, the absence of cysteine-rich motif-1-containing nodule-specific cysteine-rich peptide (NCR) genes but the recruitment of defensin-like NCRs suggest a diverse molecular mechanism of terminal bacteroid differentiation. In summary, our work describes genetic conservation and diversification in legume-rhizobia symbiosis in the Papilionoid family, as well as among members of the Dalbergoid legumes.[Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.


Assuntos
Arachis , Medicago truncatula , Arachis/genética , Arachis/microbiologia , Diferenciação Celular , Medicago truncatula/microbiologia , Fixação de Nitrogênio/genética , Nódulos Radiculares de Plantas/microbiologia , Simbiose/genética , Transcriptoma/genética
20.
Org Lett ; 23(16): 6510-6514, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34379426

RESUMO

A mild, efficient, and one-pot protocol for three-component carbosilylation of alkenes with imidazoheterocycle and silanes has been developed by merging iron(II) and visible-light photocatalysis. This C-C and C-Si bond-forming method provides functionalized organosilicon derivatives having imidazoheterocycles moieties in good yields. The reaction possibly proceeds through a radical pathway.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...