Reentrant Localization Transition in a Quasiperiodic Chain.

Systems with quasiperiodic disorder are known to exhibit a localization transition in low dimensions. After a critical strength of disorder, all the states of the system become localized, thereby ceasing the particle motion in the system. However, in our analysis, we show that in a one-dimensional dimerized lattice with staggered quasiperiodic disorder, after the localization transition, some of the localized eigenstates become extended for a range of intermediate disorder strengths. Eventually, the system undergoes a second localization transition at a higher disorder strength, leading to all states being localized. We also show that the two localization transitions are associated with the mobility regions hosting the single-particle mobility edges. We establish this reentrant localization transition by analyzing the eigenspectra, participation ratios, and the density of states of the system.

Quasiperiodic disorder induced critical phases in a periodically driven dimerized p-wave Kitaev chain.

The intricate relationship between topology and disorder in non-equilibrium quantum systems presents a captivating avenue for exploring localization phenomenon. Here, we look for a suitable platform that enables an in-depth investigation of the topic. To this end, we delve into the nuanced analysis of the topological and localization characteristics exhibited by a one-dimensional dimerized Kitaev chain under periodic driving and perform detailed analyses of the Floquet Majorana modes. Such a non-equilibrium scenario is made further interesting by including a spatially varying quasiperiodic potential with a temporally modulated amplitude. Apriori, the motivation is to explore an interplay between dimerization and a quasiperiodic disorder in a topological setting which is also known to demonstrate unique (re-entrant) localization properties. While the topological properties of the driven system confirm the presence of zero and π Majorana modes, the phase diagram obtained by constructing a pair of topological invariants ( Z × Z ), also referred to as the real space winding numbers, at different driving frequencies reveal intriguing features that are distinct from the static scenario. In particular, at either low or intermediate frequency regimes, the phase diagram concerning the zero mode involves two distinct phase transitions, one from a topologically trivial to a non-trivial phase, and another from a topological phase to an Anderson localized phase. On the other hand, the study of the Majorana π mode unveils the emergence of a unique topological phase, characterized by complete localization of both the bulk and the edge modes, which may be called as the Floquet topological Anderson phase. Moreover, different frequency regimes showcase distinct localization features which can be examined via the localization toolbox, namely, the inverse and the normalized participation ratios. Specifically, the low and high-frequency regimes demonstrate the existence of completely extended and localized phases, respectively. While at intermediate frequencies, we observe the critical (multifractal) phase of the model which is further investigated via a finite-size scaling analysis of the fractal dimension. Finally, to add depth into our study, we have performed a mean level spacing analyses and computed the Hausdorff dimension which yields specific characteristics inherent to the critical phase, offering profound insights into its underlying properties.

Clinical Outcomes and Treatment Efficacy in Cervical Cancer Patients in the UAE: A Retrospective Cohort Study.

Background and objectives Cervical cancer remains a significant global health issue, particularly in low- and middle-income countries. While high-income countries have seen reduced incidence and mortality rates due to effective screening and HPV vaccination programs, these rates are still high in areas with limited healthcare infrastructure. In the United Arab Emirates (UAE), recent efforts are improving public health initiatives and awareness. This retrospective cohort study evaluates clinical outcomes and treatment efficacy in cervical cancer patients at a tertiary cancer center in Al Ain, Abu Dhabi. It analyzes treatment regimens, their effectiveness, and factors affecting survival, disease progression, and treatment completion. Methods and material The study included 275 cervical cancer patients treated between January 2008 and December 2021. Data were extracted from medical records, including demographic information, clinical characteristics, and treatment details. Statistical analyses, including Kaplan-Meier survival curves and Cramér's V correlation matrix, were used to evaluate survival outcomes and the relationships between various categorical variables. Results The mean age of patients was 48.88 years, with the majority being non-nationals, 221 (80.37%). Histopathologically, there were 234 (85.18%) cases of squamous cell carcinoma (SCC) and 33 (11.85%) cases of adenocarcinomas. The International Federation of Gynecology and Obstetrics (FIGO) staging indicated that 137 (49.80%) patients were in stage II and 60 (21.81%) were in stage III. Pelvic lymph node involvement was observed in 139 (50.54%) patients. The treatment modalities included surgery in 39 (14.18%) patients, 3D conformal radiotherapy (3D-CRT) in 247 (89.81%) patients, intensity-modulated radiation therapy (IMRT) in 11 (4.00%) patients, brachytherapy in 213 (77.45%) patients, and chemotherapy in 248 (90.18%) patients. The survival analysis showed no significant differences in survival among different treatment groups, as indicated by the Log-rank test (p = 0.4060). Conclusion The study highlights the demographic and clinical characteristics of cervical cancer patients in the UAE, emphasizing the prevalence of advanced-stage diagnoses and high-grade tumors. Despite significant efforts to improve screening and treatment, cervical cancer remains a concern in the UAE. The findings underscore the need for enhanced early detection and comprehensive treatment strategies. Addressing the study's limitations, such as the retrospective design and the absence of human papillomavirus (HPV) data, could further refine cervical cancer management and improve patient outcomes in future research.

Endometrial Carcinoma: A Comprehensive Analysis of Clinical Parameters, Treatment Modalities, and Prognostic Outcomes at a Tertiary Oncology Center in the UAE.

Background Endometrial carcinoma (EC) remains a pressing global health issue, with a discernible upsurge in incidence, especially in developed countries. Notably, the United Arab Emirates (UAE) has witnessed a surge in EC cases, demanding an in-depth, region-specific exploration into the disease's clinical, treatment, and prognostic facets against the backdrop of its unique socio-genetic and environmental contours. Aim This study aimed to profess a comprehensive understanding of EC by examining clinical parameters, treatment modalities, and prognostic outcomes in the UAE context, thereby seeking to delineate potential correlations between varied therapeutic combinations, patient demographics, and tumor characteristics in affecting prognostic outcomes. Materials and methods A retrospective cohort study involving 93 patients diagnosed with EC from January 2011 to March 2023 at a leading oncology center in the UAE was conducted. Data, including demographic information, clinical presentation, treatment modalities, and prognostic outcomes, were meticulously extracted and analyzed. The R software (version 4.2.2) facilitated exhaustive statistical analyses, involving descriptive statistics, correlation analyses with the polycor package, and survival analyses utilizing the Kaplan-Meier method and Cox regression analysis via the survival and survminer packages, respectively. Results Although the correlation matrix revealed a noticeable relationship between "Family history" and "Age," most parameters displayed independence, offering a robust platform for ensuing multivariate analyses. Kaplan-Meier survival curves, stratified by therapeutic modalities, exhibited no statistically significant survival differences across therapeutic cohorts (p-values: 0.44, 0.86, and 0.83). Conversely, the composite Cox regression model underscored "non-national" demographic, Diabetes Mellitus II, and stromal invasion as pivotal prognostic factors, indicating the multifactorial nature of survival in EC patients and emphasizing demographic and tumor characteristics over therapeutic modalities as influential prognostic determinants. Conclusion In conclusion, while therapy types were not directly correlated with survival, demographic and tumor traits prominently impacted prognostic outcomes, advocating for an intricate, multidimensional approach to managing EC in the UAE. This study hopes to sow seeds for subsequent research, shaping clinically and culturally apt practices and policies in the region's healthcare landscape.

Conduction analysis in mixed cardiomyocytes-fibroblasts cultures using microelectrode arrays.

Models for cardiac arrhythmia currently exist primarily in in-vivo and computer simulation form. Towards the development of such a model in-vitro, a better understanding of electrical conduction in heterogeneous cultures is required. Increasing ratios of cardiomyocytes and fibroblasts were cultured on 500x500 microm arrays of 36 microelectrodes to study the emergence and properties of action potential propagation in mixed cultures. A minimum ratio of 70% cardiomyocytes to 30% fibroblasts was found to be necessary for detection of electrical activity. However, the establishment of a continuous, homogeneous depolarization wave across the culture required a higher proportion of cardiomyocytes; even a 90:10 ratio was unable to consistently produce a unidirectional, uniform depolarization wave as is seen in controls. This model underlines the importance and sensitivity of tissue homogeneity in supporting electrical conduction, and is especially relevant to studies of arrhythmia (reentry) and stem cell grafts.