54 research outputs found

    Early versus delayed flow diversion for ruptured intracranial aneurysms: A meta-analysis

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    Objective: The use and timing of flow diversion for aneurysmal subarachnoid hemorrhage is controversial. The objective of this study is to perform a meta-analysis and systematic review to compare overall complication rate between early versus delayed flow diversion for ruptured aneurysms.Methods: A literature search for all eligible articles was performed using PubMed, Cochrane, and Web of Science databases. The primary outcome was the overall complication rate (any complication in the perioperative period), and secondary outcomes were 1) hemorrhage and 2) stroke/death (all hemorrhagic/ischemic strokes and/or death).Results: Thirteen articles including 142 patients met inclusion criteria. Eighty-nine (62.7%) patients underwent early deployment of flow diverters (i.e., 2 days or less). The odds ratio for overall complication rate with early versus delayed flow diversion was 0.95 (95% confidence interval [CI] 0.36-2.49, P = 0.42). The odds ratio for the secondary outcome of hemorrhagic complication for early versus delayed flow diversion was 1.44 (95% CI 0.45-4.52, P = 0.87) and of stroke/death was 1.67 (95% CI 0.5-4.9, P = 0.69). The odds ratio of early versus delayed flow diversion for blister/dissecting/fusiform aneurysms was 0.82 (95% CI 0.29-2.30) and for saccular/giant aneurysms was 2.23 (95% CI 0.17-29.4). At last follow-up, 71.6% of patients had good performance status (modified Rankin Scale score 0-2), and the rate of angiographic aneurysm occlusion was 90.2%.Conclusions: This meta-analysis did not show a difference in overall complication rate between early versus delayed flow diversion for ruptured aneurysms. Early flow diversion for ruptured blister/fusiform/dissecting aneurysms carries a lower risk of aneurysm rerupture and overall complications as compared with that for ruptured saccular/giant aneurysms

    Quantifying intra-tumoral genetic heterogeneity of glioblastoma toward precision medicine using MRI and a data-inclusive machine learning algorithm

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    Glioblastoma (GBM) is one of the most aggressive and lethal human cancers. Intra-tumoral genetic heterogeneity poses a significant challenge for treatment. Biopsy is invasive, which motivates the development of non-invasive, MRI-based machine learning (ML) models to quantify intra-tumoral genetic heterogeneity for each patient. This capability holds great promise for enabling better therapeutic selection to improve patient outcomes. We proposed a novel Weakly Supervised Ordinal Support Vector Machine (WSO-SVM) to predict regional genetic alteration status within each GBM tumor using MRI. WSO-SVM was applied to a unique dataset of 318 image-localized biopsies with spatially matched multiparametric MRI from 74 GBM patients. The model was trained to predict the regional genetic alteration of three GBM driver genes (EGFR, PDGFRA, and PTEN) based on features extracted from the corresponding region of five MRI contrast images. For comparison, a variety of existing ML algorithms were also applied. The classification accuracy of each gene was compared between the different algorithms. The SHapley Additive exPlanations (SHAP) method was further applied to compute contribution scores of different contrast images. Finally, the trained WSO-SVM was used to generate prediction maps within the tumoral area of each patient to help visualize the intra-tumoral genetic heterogeneity. This study demonstrated the feasibility of using MRI and WSO-SVM to enable non-invasive prediction of intra-tumoral regional genetic alteration for each GBM patient, which can inform future adaptive therapies for individualized oncology.Comment: 36 pages, 8 figures, 3 table

    Razvoj i vrednovanje dvoslojnih tableta propranolol hidroklorida

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    The objective of the present research was to develop a bilayer tablet of propranolol hydrochloride using superdisintegrant sodium starch glycolate for the fast release layer and water immiscible polymers such as ethyl cellulose, Eudragit RLPO and Eudragit RSPO for the sustaining layer. In vitro dissolution studies were carried out in a USP 24 apparatus I. The formulations gave an initial burst effect to provide the loading dose of the drug followed by sustained release for 12 hrs from the sustaining layer of matrix embedded tablets. In vitro dissolution kinetics followed the Higuchi model via a non-Fickian diffusion controlled release mechanism after the initial burst release. FT-IR studies revealed that there was no interaction between the drug and polymers used in the study. Statistical analysis (ANOVA) showed no significant difference in the cumulative amount of drug release after 15 min, but significant difference (p 0.005) in the amount of drug released after 12 h from optimized formulations was observed.U radu je opisan razvoj dvoslojnih tableta propranolol hidroklorida, koristeći superdezintegrator škrob glikolat natrij u sloju za brzo oslobađanje i polimere koji se ne miješaju s vodom (etil celuloza, Eudragit RLPO i Eudragit RSPO) u sloju za usporeno oslobađanje. In vitro oslobađanje praćeno je u USP aparatu I te je uočeno početno naglo oslobađanje ljekovite tvari iza kojeg slijedi polagano oslobađanje tijekom 12 sati. In vitro kinetika oslobađanja prati Higouchijev model, dok mehanizam kontroliranog oslobađanja ne slijedi Fickov zakon poslije početnog naglog oslobađanja. FT-IR studije ukazuju da nema interakcije između ljekovite tvari i polimera upotrebljenih u oblikovanju. Statistička analiza (ANOVA) nije pokazala značajne razlike u kumulativnoj količini oslobođenog lijeka iz optimiranih formulacija poslije 15 minuta i polije 12 h

    Hydrogen Epoch of Reionization Array (HERA) Phase II Deployment and Commissioning

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    This paper presents the design and deployment of the Hydrogen Epoch of Reionization Array (HERA) phase II system. HERA is designed as a staged experiment targeting 21 cm emission measurements of the Epoch of Reionization. First results from the phase I array are published as of early 2022, and deployment of the phase II system is nearing completion. We describe the design of the phase II system and discuss progress on commissioning and future upgrades. As HERA is a designated Square Kilometre Array pathfinder instrument, we also show a number of “case studies” that investigate systematics seen while commissioning the phase II system, which may be of use in the design and operation of future arrays. Common pathologies are likely to manifest in similar ways across instruments, and many of these sources of contamination can be mitigated once the source is identified

    Space charge induced augmented dielectric permittivity and improved energy harvesting ability of nano-Ag decorated ZnSnO3 filled PVDF based flexible nanogenerator

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    Here we report the effect of conducting Ag decoration on ZnSnO3 filler surface on the dielectric and mechanical energy harvesting performance of the resulting PVDF based composite films. The room temperature dielectric permittivity significantly enhanced for Ag@ZnSnO3 loaded PVDF compared to that of the ZnSnO3 loaded PVDF films through the effect of improved space charge polarization after Ag decoration on ZnSnO3 filler. The dielectric permittivity of the composite films was found to be increased gradually with the increase in the Ag concentration on ZnSnO3 filler surface. All the films exhibited low value of dielectric loss ((<)0.05 at 10 kHz) which proved their good applicability in flexible dielectrics. The improved polarization enhanced the mechanical energy harvesting performance of the composite films. The output peak to peak open circuit ac voltage (V-OC) for Ag@ZnSnO3-PVDF (5A10ZS) (with maximum Ag concentration on ZnSnO3 in the present experiment) film after repeated human finger tapping on it was found to be increased to similar to 20 V from a value of similar to 3.5 V and 11 V for neat PVDF and ZnSnO3-PVDF (5ZS) films, respectively. A 10 mu F capacitor was charged to similar to 3.8 V dc after rectification of output V-OC from 5A10ZS sample by 270 s of applied stress on it. During discharging, this dc electrical signal was able to light up some LEDs (connected in parallel) together instantaneously which proved the real life applicability of the nanogenerator device in self-powered flexible electronics

    Hydroxylated BiFeO3 as efficient fillers in poly(vinylidene fluoride) for flexible dielectric, ferroelectric, energy storage and mechanical energy harvesting application

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    Here we report the effect of surface hydroxylation of BiFeO3 fillers on the dielectric, ferroelectric, energy storage and mechanical energy harvesting performance of poly(vinylidene fluoride). Surface hydroxylation helped to improve the interfacial interaction between the filler and PVDF matrix by introducing a strong hydrogen bonding between the -OH group of the hydroxylated BiFeO3 filler surface and the -CF2 dipole of PVDF in place of electrostatic interfacial interaction between non-hydroxylated BiFeO3 and the -CH2 dipole of PVDF. The amount of polar phase increased to around 91% for a 7 wt% hydroxylated BiFeO3 loaded PVDF film (7BFOH) by this new type of interfacial interaction. The dielectric, ferroelectric, energy storage and mechanical energy harvesting performance of the PVDF based composite films also improved by the above said technique. Upon repeated human finger tapping, the 7BFOH film delivered similar to 18 V output peak to peak open circuit ac voltage (V-OC). After rectification, the V-OC of the 7BFOH film was able to charge a 10 mu F capacitor up to similar to 3 V which was able to light up some LEDs (connected in parallel) together instantaneously, which proved the real life applicability of the composite films in low power consuming self-powered electronic devices

    Lithium doping and photoluminescence properties of ZnO nanorods

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    This article presents a comprehensive experimental study of optical properties of Li-doped ZnO nanorods grown by a low temperature (300 °C) thermal decomposition method. In particular, a study of the room temperature photoluminescence spectra dependence on the Li concentration is presented here. The doping of Li in ZnO nanorods results in a redshift in near band edge emission (NBE) compared to the undoped ZnO nanorods. Depending on the Li concentration, we observe a green emission in Photoluminescence spectra. The possible physical mechanisms governing the visible region luminescence are also discussed. These results show that Li-doped ZnO nanorods with strong visible region luminescence have potential applications in optoelectronic devices

    Annular Pancreas: A Rare Cause of Duodenal Obstruction in Adults

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    Annular pancreas is an uncommon congenital anomaly which usually presents itself in infants and newborn. Rarely it can present in late adult life with wide range of clinical severities thereby making its diagnosis difficult. Pre-operative diagnosis is often difficult. CT scan can illustrate the pancreatic tissue encircling the duodenum. ERCP and MRCP are useful in outlining the annular pancreatic duct. Surgery still remains necessary to confirm diagnosis and bypassing the obstructed segment.We report a case of 61 year female presenting with duodenal obstruction due to annular pancreas
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