Implementation of Linear Stability Theory on Hollow Cone-shaped Liquid Sheet

Surface instability of a swirling liquid sheet emanating from a centrifugal injector in presence of external and internal gas flows is studied in this paper. A three-dimensional flow for the liquid sheet and two-dimensional flows for external and internal gas flows are considered. The set of equations involved in this analysis differs from the earlier analyzes. In previous studies, a cylindrical liquid sheet has been considered to implement the linear theory but in this study, the linear stability theory is implemented on a cone-shaped liquid sheet for different cone angles. Actually more over than axial and tangential movements, the radial movements of liquid sheet and gas flows are considered in the present model. Due to complexity of the derived governing equations, semi-analytical and numerical methods were applied to solve them. The case study is oxidizer injector of rocket engines. Implementation of linear stability theory on a hollow cone-shaped liquid sheet better can predict instability phenomenon than the general linear stability analysis for this type of liquid sheets. The results show very close agreement with available experimental data

Predictive data mining approaches in medical diagnosis: A review of some diseases prediction

Due to the increasing technological advances in all fields, a considerable amount of data has been collected to be processed for different purposes. Data mining is the process of determining and an-alyzing hidden information from different perspectives to obtain useful knowledge. Data mining can have many various applications, one of them is in medical diagnosis. Today, many diseases are regarded as dangerous and deadly. Heart disease, breast cancer, and diabetes are among the most dangerous ones. This paper investigates 168 articles associated with the implementation of data mining for diagnosing such diseases. The study concentrates on 85 selected papers which have received more attention between 1997 and 2018. All algorithms, data mining models, and evaluation methods are thoroughly reviewed with special consideration. The study attempts to determine the most efficient data mining methods used for medical diagnosing purposes. Also, one of the other significant results of this study is the detection of research gaps in the application of data mining in health care

Personalized Anomaly Detection in PPG Data using Representation Learning and Biometric Identification

Photoplethysmography (PPG) signals, typically acquired from wearable devices, hold significant potential for continuous fitness-health monitoring. In particular, heart conditions that manifest in rare and subtle deviating heart patterns may be interesting. However, robust and reliable anomaly detection within these data remains a challenge due to the scarcity of labeled data and high inter-subject variability. This paper introduces a two-stage framework leveraging representation learning and personalization to improve anomaly detection performance in PPG data. The proposed framework first employs representation learning to transform the original PPG signals into a more discriminative and compact representation. We then apply three different unsupervised anomaly detection methods for movement detection and biometric identification. We validate our approach using two different datasets in both generalized and personalized scenarios. The results show that representation learning significantly improves anomaly detection performance while reducing the high inter-subject variability. Personalized models further enhance anomaly detection performance, underscoring the role of personalization in PPG-based fitness-health monitoring systems. The results from biometric identification show that it's easier to distinguish a new user from one intended authorized user than from a group of users. Overall, this study provides evidence of the effectiveness of representation learning and personalization for anomaly detection in PPG data

Myopic regression after photorefractive keratectomy: a retrospective cohort study

Background: Myopic regression is a major complication of photorefractive keratectomy (PRK). The rates and causes vary considerably among different studies. This study aimed to investigate myopic regression at six months after myopic PRK. Methods: In this retrospective cohort study, we included all eligible patients with myopia ranging from - 0.75 to - 9 D, aged 18 to 50 years, who underwent PRK by a single surgeon with the availability of preoperative and postoperative data at six months after the initial procedure. All participants underwent comprehensive ophthalmic examinations preoperatively and at six months post-PRK. Overcorrection was planned based on the participant’s age range to achieve the desired refractive result after PRK. All patients received the same postoperative antibiotic and steroid eye drops in a similar dosage regimen, and the contact lenses were removed after complete corneal epithelial healing. Based on the spherical equivalent of refraction six months after PRK, eyes without and with myopic regression were allocated into groups 1 and 2, respectively. Results: We included 254 eyes of 132 patients who underwent myopic PRK with a mean (standard deviation) age of 30.12 (7.48) years; 82 (62.12%) were women and 50 (37.88%) were men. The frequency of myopic regression was significantly lower in patients with younger age, lower preoperative cylindrical refraction, and lower ablation depth (all P < 0.05). Overcorrection was more successful in eyes with low myopia than in eyes with high myopia (P < 0.05). The highest frequency of myopic regression occurred in eyes with moderate myopia (25.68%), followed by eyes with high myopia (20.0%) and low myopia (6.54%). Among different age groups, patients aged less than or equal to 30 years had a lower frequency of myopic regression. The frequency of myopic regression in the different age groups was 5.0% at 18-20 years, 7.46% at 26-30 years, 12.28% at 21-25 years, 21.31% at 31-35 years, and 26.53% at 36-50 years. Conclusions: Overcorrection was more successful in eyes with low myopia than in eyes with high myopia. The success rate was higher in younger patients with lower astigmatism and ablation depths. Myopic regression was most frequent in eyes with moderate myopia, followed by those with high and low myopia. Further studies should replicate our findings over a longer follow-up period with a larger sample size before generalization is warranted

Cu(II)-Schiff base covalently anchored to MIL-125(Ti)-NH2 as heterogeneous catalyst for oxidation reactions

[EN] MIL-125(Ti)-NH2 has been modified by reaction of salicylaldehyde with the terephthalate amino groups to form a salicylideneimine that act as ligand of Cu2+. The success of the postsynthetic modification was assessed by FTIR spectroscopy of the MIL-125(Ti)-NH2-Sal-Cu and by analysis by H-1 NMR spectroscopy of the organic linkers upon dissolution of MIL-125(Ti)-NH2-Sal-Cu. In comparison with parent MIL-125(Ti)-NH2 and MIL-125(Ti)-NH2-Sal, that exhibit a poor activity, the presence of the Cu-Schiff base complex in MIL-125(Ti)-NH2-Sal-Cu catalyst for the oxidation of 1-phenylethanol by tert-butylhydroperoxyde (TBHP, 3 eq.) increases notably the catalytic activity. Hot filtration test and reusability experiments confirm that the process is heterogeneous and that MIL-125(Ti)-NH2-Sal-Cu is stable under the reaction conditions. Quenching studies and EPR spectra using N-(t)butylphenylnitrone indicate the generation of (BuOO)-Bu-t. and (BuO center dot)-Bu-t under the reaction conditions. The scope of MIL-125(Ti)-NH2-Sal-Cu as oxidation catalyst by (BuOOH)-Bu-t was studied for benzyl alcohol as well as alicyclic and aliphatic alcohols and ethylbenzene. (C) 2018 Elsevier Inc. All rights reserved.Financial support by the Spanish Ministry of Economy and Competitiveness (Severo Ochoa) CTQ2014-53292-R is gratefully acknowledged. Generalidad Valenciana is also thanked for funding (Prometeo 2017/063). S.D., A.R.O., D.A., and R.G-V thank H.G., S.N. and M.A., S.D., D.A., and R.G-V gratefully acknowledge financial support from Bu-Ali Sina University. S.N. thanks financial support by the Fundacion Ramon Areces (XVIII Concurso Nacional para la Adjudicacion de Ayudas a la Investigacion en Ciencias de la Vida y de la Materia, 2016).Daliran, S.; Santiago-Portillo, A.; Navalón Oltra, S.; Reza Oveisi, A.; Alvaro Rodríguez, MM.; Ghorbani-Vaghei, R.; Azarifar, D.... (2018). Cu(II)-Schiff base covalently anchored to MIL-125(Ti)-NH2 as heterogeneous catalyst for oxidation reactions. Journal of Colloid and Interface Science. 532:700-710. https://doi.org/10.1016/j.jcis.2018.07.140S70071053

Sentinel lymph node biopsy in upper tract urothelial cancers: an experience with intraoperative radiotracer injection

Background: The feasibility of the sentinel node mapping in upper tract urothelial cancers (UTUC) was evaluated, using a radiotracer as the mapping material. Material and methods: To identify the sentinel lymph nodes, 37 MBq of [99mTc] phytate was injected in five patients with the renal pelvis or ureter cancer, who were candidates for ureterectomy and lymphadenectomy. The radiotracer was injected in a peritumoral fashion following the surgical exposure of the tumour. The sentinel lymph nodes were detected using a handheld gamma probe. Results: By intraoperatively injecting the radiotracer immediately after surgical exposure of the tumour, at least one sentinel lymph node could be detected in each patient, and the detection rate was 100%. The location of sentinel nodes was in the paracaval, renal hill, retro-aortic, para-aortic, common iliac, and external iliac areas, which was dependent on the tumour location. No false-negative case was identified. Conclusions: Sentinel node mapping is feasible in UTUC. Injection technique (intra-vesical approach vs peri-tumoral injection after exposure of the tumour) and location of the tumour (proximal vs distal) may affect the technique’s feasibility