A level set approach to segmenting a deforming myocardium from dynamically acquired SPECT projection data

Dynamic cardiac single photon emission computed tomography (SPECT) offers an effective way for observing fundamental physiological functions of organs and could aid in the early diagnosis of cardiovascular disease, in particular, for those patients with minimal disease. This would improve the chances of recovery by initiating appropriate therapy and an altered life style. To make dynamic cardiac SPECT viable with present clinical scanners methods need to be developed that reconstruct time activity curves from dynamically moving organs representing the change of tracer concentration as a function of time from projection data acquired from slowly rotating gamma cameras. This type of data analysis faces the challenge of modeling both rigid and non-rigid body deformation as well as modeling of a time varying tracer concentration. In the work presented here, we develop methods for segmenting the beating heart using an approach based upon level sets, which can deal naturally with topological changes. A variational formulation of the level set method was implemented. This allowed the inclusion of a priori information and was computationally efficient. The algorithm was first evaluated with simulated dynamic cardiac image data. The MCAT phantom was used to generate data containing 32 time frames over one cardiac cycle. Each frame had a matrix size of 64×64×32 voxels with a resolution of 6.25 mm. Starting with an initial estimate of the boundary, the algorithm then converged to an accurate segmentation of the deforming heart. The initial estimate was not important and we could segment simultaneously both interior and exterior boundaries. This algorithm forms the foundation for the segmentation of the boundary of the deforming myocardium directly from projection data

Cellulose acetate membranes functionalized with resveratrol by covalent immobilization for improved osseointegration

Covalent immobilization of resveratrol onto cellulose acetate polymeric membranes used as coating on a Mg-1Ca-0.2Mn-0.6Zr alloy is presented for potential application in the improvement of osseointegration processes. For this purpose, cellulose acetate membrane is hydrolysed in the presence of potassium hydroxide, followed by covalent immobilization of aminopropyl triethoxy silane. Resveratrol was immobilized onto membranes using glutaraldehyde as linker. The newly synthesised functional membranes were thoroughly characterized for their structural characteristics determination employing X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (FT-IR), Raman spectroscopy, thermogravimetric analysis (TGA/DTG) and scanning electron microscopy (SEM) techniques. Subsequently, in vitro cellular tests were performed for evaluating the cytotoxicity biocompatibility of synthesized materials and also the osseointegration potential of obtained derivatised membrane material. It was demonstrated that both polymeric membranes support viability and proliferation of the pre-osteoblastic MC3T3-E1 cells, thus providing a good protection against the potential harmful effects of the compounds released from coated alloys. Furthermore, cellulose acetate membrane functionalized with resveratrol exhibits a significant increase in alkaline phosphatase activity and extracellular matrix mineralization, suggesting its suitability to function as an implant surface coating for guided bone regeneration

Retrosigmoid approach for a ruptured pontine cavernous malformation, in a 10 years old pacient: Case report

Brainstem cavernous malformations have a high risk of hemorrhage, ranging from 4 to 60%, this risk being even higher in children where larger lesions are encountered. Even small hemorrhages can cause ,severe neurological symptoms because of the high density of cranial nerve nuclei and fiber tracts within the brainstem. The goal of surgical treatment is not only the improvement of neurological symptoms, but also preservation of the patient’s quality of life. We present a case of a 10 years old female pacient who presented after a 5 weeks conservative treatment with right sided weakness and loss of coordination, right hemihipoesthesia, She was diagnosed with a large left pontine cavernous malformation on MRI. The cavernoma was resected using a retrosigmoidian approach , but a small remnant was left, when the surgery had to be stopped due to severe bradicardia. The neurological deficit improved at follow up.The choice of the surgical approach that allows the best exposure of the lesion is mandatory. In this case the lesion was evident on the surface of the brainstem and this facilitated its resection. Traction on the tumor and coagulation near the cranial nerves nuclei should be avoided, but if bradicardia appears the surgery must be stopped.Surgery is the best choice for the patients with symptomatic brainstem cavernomas that present with hemorrhage and neurological deficit, and its objectives should be complete removal and improvement of neurological deficit.&nbsp

Dataset of electrophysiological patch-clamp recordings of the effect of the compounds deltamethrin, ATx-II and β4-peptide on human cardiac Nav1.5 sodium channel gating properties.

This article describes the effect of the pyrethroid insecticide deltamethrin on the cardiac voltage-gated sodium channel Nav1.5. Two concentrations of deltamethrin were used and the effects were compared with those of the sea anemone toxin ATx-II and β4-peptide, which is the C-terminus of the Nav channel β-subunit. Activation, fast inactivation, deactivation, persistent currents and resurgent currents of Nav1.5 channels were assessed in the presence of these compounds. The data display not only the effect of separately applied compounds on Nav1.5 channels but also investigates how combinations of these substances affect Nav1.5 channel gating properties. The dataset presented in this article is related to the research article "Mechanism underlying hooked resurgent-like tail currents induced by an insecticide in human cardiac Nav1.5″ (Sarah Thull, Cristian Neacsu, Andrias O. O'Reilly, Stefanie Bothe, Ralf Hausmann, Tobias Huth, Jannis Meents, Angelika Lampert, doi: 10.1016/j.taap.2020.11501), that investigates the effect of the pyrethroid insecticide deltamethrin on Nav channel gating properties and explains the mechanism underlying hooked, resurgent-like tail currents induced by deltamethrin in Nav1.5 channels

Surgical treatment and outcome of cerebral cavernomas: A 10 years’ experience

Cavernous malformations (cavernomas) are congenital low flow angiographic occult vascular lesions with a high tencency to bleeding. The prevalence of cerebral cavernous vascular malformations is estimated to be 0.4% to 0.9%.2,7 CMs in deep locations, including the brainstem, thalamus, and basal ganglia, account for 9% to 35% of all malformations in the brain. We performed a retrospective 10 years study on 130 operated cerebral cavernomas and discussed the clinical status at presentation, the choice and timing of the surgical approach and the short and longterm follow up. The 130 operated cases were divided into a supratentorial 102 (78.46%) group and an infratantorial group 28 (21.53%). The average age at presentation was 43,62 years old (17-76) and there was no sex predominance, male/female = 1,44 (77/53). Only in 14 cases (10.76%) we could find multiple cavernomas which had relatives with multiple cavrnomas, but the familial inheritance was not studied, and only the symptomatic lesion was resected. We divided the outcome results reporting for agroup with superficial respectively profound lesions. The long term follow up for the patients in the profound lesions group showed that 31/37 (83,78%) of patients had a mRS between 0 and 2, and the rest had a poor long term outcome. After surgery there was no clinical deterioration in the superficial lesions group and 22 patients from those who presented in mRS 2 showed neurological improvement on long term follow up, meaning that 82,79% of patients had a 0 or 1 mRS. Microsurgery is the treatment of choice in symptomatic brain cavernomas, total resection being the only curative treatment, capable to prevent further bleeding and to offer an efficient control of seizures.Key words: cavernous malformation, microneurosurgery, seizures

Confidence does not mediate a relationship between owner experience and likelihood of using weight management approaches for native ponies

Funding: This study was funded by Mars Petcare and is part of a PhD studentship funded by the Scottish Funding Council Research Excellence Grant (REG). Authors WR and MN receive salary support from the Rural and Environment Science and Analytical Services Division (RESAS). With the exception of PH (employed by the funding organization), the funding organization did not have any additional role in the conceptualization, methodology, investigation, data curation, formal analysis, decision to publish, or preparation of the manuscript. PH was involved in study design, data interpretation, and manuscript preparation.Peer reviewedPublisher PD

Clip reconstruction of a large right MCA bifurcation aneurysm: Case report

We report a case of complex large middle cerebral artery (MCA) bifurcation aneurysm that ruptured during dissection from the very adherent MCA branches but was successfully clipped and the MCA bifurcation reconstructed using 4 Yasargill clips. Through a right pterional craniotomy the sylvian fissure was largely opened as to allow enough workspace for clipping the aneurysm and placing a temporary clip on M1.The pacient recovered very well after surgery and was discharged after 1 week with no neurological deficit. Complex MCA bifurcation aneurysms can be safely reconstructed using regular clips, without the need of using fenestrated clips or complex by-pass procedures

Advanced Scanning Electron Microscopy Methods and Applications to Integrated Circuit Failure Analysis

Semiconductor device failure analysis using the scanning electron microscope (SEM) has become a standard component of integrated circuit fabrication. Improvements in SEM capabilities and in digital imaging and processing have advanced standard acquisition modes and have promoted new failure analysis methods. The physical basis of various data acquisition modes, both standard and new, and their implementation on a computer controlled SEM image acquisition/processing system are discussed, emphasizing the advantages of each method. Design considerations for an integrated, online failure analysis system are also described. Recent developments in the integration of the information provided by electron beam analysis, conventional integrated circuit (IC) testing, computer-aided design (CAD), and device parameter testing into a single system promise to provide powerful future tools for failure analysis