A switching synchronization scheme for a class of chaotic systems

In this Letter, we propose an observer-based synchronization scheme for a class of chaotic systems. This class of systems are given by piecewise-linear dynamics. By using some properties of such systems, we give a procedure to construct the gain of the observer. We prove various stability results and comment on the robustness of the proposed scheme. We also present some simulation results. © 2002 Elsevier Science B.V. All rights reserved

Multi-aspect analysis of ureteral access sheath usage in retrograde intrarenal surgery: A RIRSearch group study

Objective: To evaluate the effect of ureteral access sheath (UAS) use and calibration change on stone-free rate and complications of retrograde intrarenal surgery (RIRS). Methods: Data from 568 patients undergoing RIRS for kidney or upper ureteral stones were retrospectively included. Firstly, patients were compared after 1:1 propensity score matching, according to UAS usage during RIRS (UAS used [+] 87 and UAS non-used [?] 87 patients). Then all UAS+ patients (n=481) were subdivided according to UAS calibration: 9.5–11.5 Fr, 10–12 Fr, 11–13 Fr, and 13–15 Fr. Primary outcomes of the study were the success and complications of RIRS. Results: Stone-free rate of UAS+ patients (86.2%) was significantly higher than UAS? patients (70.1%) after propensity score matching (p=0.01). Stone-free rate increased with higher caliber UAS (9.5–11.5 Fr: 66.7%; 10–12 Fr: 87.3%; 11–13 Fr: 91.3%; 13–15 Fr: 100%; p<0.0001). Postoperative complications of UAS+ patients (11.5%) were significantly lower than UAS? patients (27.6%) (p=0.01). Complications (8.7%) with 9.5–11.5 Fr UAS was lower than thicker UAS (17.3%) but was not statistically significant (p=0.08). UAS usage was an independent factor predicting stone-free status or peri- and post-operative complications (odds ratio [OR] 3.654, 95% confidence interval [CI] 1.314–10.162; OR 4.443, 95% CI 1.350–14.552; OR 4.107, 95% CI 1.366–12.344, respectively). Conclusion: Use of UAS in RIRS may increase stone-free rates, which also increase with higher caliber UAS. UAS usage may reduce complications; however, complications seemingly increase with higher UAS calibration. © 2022 Editorial Office of Asian Journal of Urolog

NUMERICAL RECONSTRUCTION OF A SPACE-DEPENDENT SOURCE TERM FOR MULTIDIMENSIONAL SPACE-TIME FRACTIONAL DIFFUSION EQUATIONS

In this paper, we consider the problem of identifying the unknown source function in the time-space fractional diffusion equation from the final observation data. An implicit difference technique is proposed in conjunction with the matrix transfer scheme for approximating the solution of the direct problem. The challenge pertains to an inverse scenario encompassing a nonlocal ill-posed operator. The problem under investigation is formulated as a regularized optimization problem with a least-squares cost function minimization objective. An approximation for the source function is obtained using an iterative non-stationary Tikhonov regularization approach. Three numerical examples are reported to verify the efficiency of the proposed schemes. © 2023, Publishing House of the Romanian Academy. All rights reserved.Deanship of Scientific Research, Imam Mohammed Ibn Saud Islamic University: IMSIU-RP23095Acknowledgements. This work was supported and funded by the Deanship of Scientific Research at Imam Mohammad Ibn Saud Islamic University (IMSIU) (grant number IMSIU-RP23095)

Pharmacological Properties of Edible Asparagus acutifolius and Asparagus officinalis Collected from North Iraq and Turkey (Hatay)

In this study, antioxidant, oxidant, antimicrobial, and antiproliferative activities of Asparagus acutifolius L. and Asparagus officinalis L., known for their nutritional properties, were determined. In this context, methanol (MeOH) and dichloromethane (DCM) extracts of plants were obtained. Total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) were determined using Rel Assay kits. Antimicrobial activities of plant extracts were determined against the test microorganisms using the agar dilution method. Antiproliferative activity was tested on the lung cancer cell line A549. As a result of the studies, it has been determined that the plant species have high antioxidant potential. In addition, it was observed that the antifungal potentials of plant extracts are high. Antiproliferative activity was determined to be at high level in both plant species. As a result, it has been determined that A. acutifolius and A. officinalis have medical potential and can be used as natural agents in pharmacological designs

HPV16 Oncoproteins Induce MMPs/RECK-TIMP-2 Imbalance in Primary Keratinocytes: Possible Implications in Cervical Carcinogenesis

Cervical cancer is the third most common cancer in women worldwide. Persistent infection with high-risk HPV types, principally HPV16 and 18 is the main risk factor for the development of this malignancy. However, the onset of invasive tumor occurs many years after initial exposure in a minority of infected women. This suggests that other factors beyond viral infection are necessary for tumor establishment and progression. Tumor progression is characterized by an increase in secretion and activation of matrix metalloproteinases (MMPs) produced by either the tumor cells themselves or tumor-associated fibroblasts or macrophages. Increased MMPs expression, including MMP-2, MMP-9 and MT1-MMP, has been observed during cervical carcinoma progression. These proteins have been associated with degradation of ECM components, tumor invasion, metastasis and recurrence. However, few studies have evaluated the interplay between HPV infection and the expression and activity of MMPs and their regulators in cervical cancer. We analyzed the effect of HPV16 oncoproteins on the expression and activity of MMP-2, MMP-9, MT1-MMP, and their inhibitors TIMP-2 and RECK in cultures of human keratinocytes. We observed that E7 expression is associated with increased pro-MMP-9 activity in the epithelial component of organotypic cultures, while E6 and E7 oncoproteins co-expression down-regulates RECK and TIMP-2 levels in organotypic and monolayers cultures. Finally, a study conducted in human cervical tissues showed a decrease in RECK expression levels in precancer and cancer lesions. Our results indicate that HPV oncoproteins promote MMPs/RECK-TIMP-2 imbalance which may be involved in HPV-associated lesions outcome