88 research outputs found

    Gentzen-Prawitz Natural Deduction as a Teaching Tool

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    We report a four-years experiment in teaching reasoning to undergraduate students, ranging from weak to gifted, using Gentzen-Prawitz's style natural deduction. We argue that this pedagogical approach is a good alternative to the use of Boolean algebra for teaching reasoning, especially for computer scientists and formal methods practionners

    BAXMC: a CEGAR approach to Max\#SAT

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    Max\#SAT is an important problem with multiple applications in security and program synthesis that is proven hard to solve. It is defined as: given a parameterized quantifier-free propositional formula compute parameters such that the number of models of the formula is maximal. As an extension, the formula can include an existential prefix. We propose a CEGAR-based algorithm and refinements thereof, based on either exact or approximate model counting, and prove its correctness in both cases. Our experiments show that this algorithm has much better effective complexity than the state of the art.Comment: FMCAD 2022, Oct 2022, Trente, Ital

    Prosthetically driven implant planning

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    Ilarion Postolachi Department of Prosthodontics, Nicolae Testemitanu State University of Medicine and Pharmacy, Chisinau, Republic of Moldova, The 8th International Medical Congress for Students and Young Doctors, September 24-26, 2020Introduction. Ideal implant treatment planning requires close collaboration between the prosthodontist and the surgeon to determine the optimal placement of the implant in relation to the available bone and the prosthetic requirements. The ideal placement of dental implants should be determined by prosthetic parameters which depend on the position of a tooth in the arch and occlusion. The exact position of the implant in the bone with respect to location and angulation is often difficult to accurately achieve. Aim of the study. Evaluation of the most commonly used surgical guides for backward planning. Materials and methods.. Five patients, 3 men and 2 women (aged between 30 and 50 years old), have been included in the research. Two cases out of 5 were with frontal single tooth edentation, 1 patient had Kennedy Class II partial edentation, 1 patient with Kennedy Class I edentation and 1 patient with complete edentulism. Ten implants of 2 stages were inserted with partially guided surgery (static guided surgery). One-demand software was used for CBCT analysis and for planning. The Blue Sky Plan and 3Shape softwares were used for surgical guide fabrication. As for the initial planning in 4 cases wax up had been made and scanned, in 1 case for CBCT patient’s old prosthesis had been contrasted. Different surgical guides have been used: 3 of them were tooth-supported, 1 was tooth and tissue supported and 1 was solely tissue supported without the usage of support pins. The deviation degree was analyzed after the implantation by merging the CBCT with the initial planning. Results. In this study, 1 surgical guide was fractured, another surgical had positioning difficulties wich required adjustment. Other guides fitted with no adjustments. After the radiological evaluation it was found a favorable/good angulation and position wich was almost alike with the one planned initilally. Conclusions. It can be concluded that the surgical guides will continue to be a valuable adjunct to achieve precision in today’s prosthetic driven implantology. Backward planning allows for a precise and predictable implant placement that improves the communication between prosthodontist and surgeon with the acheivement of a better result of the treatment

    Urine cell-based DNA methylation classifier for monitoring bladder cancer

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    Background: Current standard methods used to detect and monitor bladder cancer (BC) are invasive or have low sensitivity. This study aimed to develop a urine methylation biomarker classifier for BC monitoring and validate this classifier in patients in follow-up for bladder cancer (PFBC). Methods: Voided urine samples (N = 725) from BC patients, controls, and PFBC were prospectively collected in four centers. Finally, 626 urine samples were available for analysis. DNA was extracted from the urinary cells and bisulfite modificated, and methylation status was analyzed using pyrosequencing. Cytology was available from a subset of patients (N = 399). In the discovery phase, seven selected genes from the literature (CDH13, CFTR, NID2, SALL3, TMEFF2, TWIST1, and VIM2) were studied in 111 BC and 57 control samples. This training set was used to develop a gene classifier by logistic regression and was validated in 458 PFBC samples (173 with recurrence). Results: A three-gene methylation classifier containing CFTR, SALL3, and TWIST1 was developed in the training set (AUC 0.874). The classifier achieved an AUC of 0.741 in the validation series. Cytology results were available for 308 samples from the validation set. Cytology achieved AUC 0.696 whereas the classifier in this subset of patients reached an AUC 0.768. Combining the methylation classifier with cytology results achieved an AUC 0.86 in the validation set, with a sensitivity of 96%, a specificity of 40%, and a positive and negative predictive value of 56 and 92%, respectively. Conclusions: The combination of the three-gene methylation classifier and cytology results has high sensitivity and high negative predictive value in a real clinical scenario (PFBC). The proposed classifier is a useful test for predicting BC recurrence and decrease the number of cystoscopies in the follow-up of BC patients. If only patients with a positive combined classifier result would be cystoscopied, 36% of all cystoscopies can be prevented

    Subacute myoclonic measles encephalitis – An opportunistic HIV-associated infection

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    IntroductionAn unusual cluster of myoclonic epilepsy was observed in a Romanian pediatric HIV cohort concurrent with measles outbreaks. We describe this particular form of subacute measles encephalitis (SME) in a group of HIV-infected children and adolescents with severe immunosuppression.MethodsThis is a single-center study, starting in 1997 and covering 4 measles outbreaks in Romania. The presumptive diagnosis of subacute myoclonic measles encephalitis (SMME) was based on: (1) epidemiological data, previous measles episode or presumed contact with measles virus (MV), (2) clinical presentation with initial localized myoclonic jerks with rapid extension and subsequent motor deficit with preserved mental status, and (3) neuroimaging studies revealing cortical gray matter lesions. Definitive diagnosis was based on a neuropathological exam and immunohistochemistry of brain tissues, and measles RNA detection in the cerebrospinal fluid (CSF).ResultsThirty-six patients were diagnosed with a particular form of SME during consecutive measles outbreaks in Romania: 1996–1998 (22); 2005–2008 (12); 2010–2011 (1) and 2016-2018 (1). Most children were born in the late 80s and had parenterally acquired HIV infection in early childhood. Before the episode of SMME, 11 patients had confirmed measles, while the rest, without typical rash, had a respiratory tract infection and/or presumed previous measles contact. In all patients, the clinical onset was sudden, with unilateral myoclonus. MRI findings revealed mainly focal cortical gray matter lesions. Neurologic symptoms progressed rapidly to coma and death in most patients. Three patients survived SMME, they had higher CD4 count at onset, slower progression of neurological symptoms, and benefit of immune recovery with cART. Immunocytochemistry studies revealed MV in the brain with a pattern suggesting an ascending viral neural infection. MV was isolated from CSF in 7 out of 8 patients. Sequence analysis of MV RNA from both nasopharyngeal swabs and CSF was available for one patient with similar N-450 strain characteristics.ConclusionDuring an outbreak of measles, neurological manifestations, especially myoclonus in immunosuppressed patients, can be related to measles even in the absence of an acute episode. This particular form of subacute myoclonic measles encephalitis is an opportunistic fatal disease. Immune recovery due to effective antiretroviral treatment might increase survival

    The effects of 6-weeks program of physical therapeutic exergames on cognitive flexibility focused by reaction times in relation to manual and podal motor abilities

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    The main purpose of the study was to identify the level of improvement in cognitive flexi-bility manifested by choice and cognition reaction times in relation to manual and podal skills as a result of the implementation of a program of therapeutic exergame exercises, for a time interval of 6 weeks at the level of students. 511 students participated in the cross-sectional study, of which 279 male (54.6%) and 232 female (45.4%), divided into two groups: the experimental group 266 (521%) subjects and the control group 245 (48%) sub-jects. The implementation of the experimental program comprising of 8 physical thera-peutic exergames took place for 6 weeks, in one session per week, within the physical edu-cation lessons, only for the male and female experimental groups. In the initial and final testing session, 2 standardized tests were applied: TMT part A, B and 2 tests adapted for this study: Square Test and 25 Squares Test. The progress registered by the male and fe-male experimental groups was statistically significant. In all tests, the experimental groups showed higher progress compared to the control groups. Depending on the gender differences, it was found that the male experimental and control groups made better pro-gress compared to the female groups in the following tests: TMT part A, Square Test, 25 Squares Tests. The implementation of a physical therapeutic exergame program deter-mined the improvement of cognitive flexibility man-ifested by choice and cognitive reac-tion times in conditions of manual and podal motor skills, demonstrating the effective-ness of exergame technologies adapted and implemented for prophy-lactic purpose

    Generation of an in vitro 3D PDAC stroma rich spheroid model

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    Pancreatic ductal adenocarcinoma (PDAC) is characterized by a prominent desmoplastic/stromal reaction, which contributes to the poor clinical outcome of this disease. Therefore, greater understanding of the stroma development and tumor-stroma interactions is highly required. Pancreatic stellate cells (PSC) are myofibroblast-like cells that located in exocrine areas of the pancreas, which as a result of inflammation produced by PDAC migrate and accumulate in the tumor mass, secreting extracellular matrix components and producing the dense PDAC stroma. Currently, only a few orthotopic or ectopic animal tumor models, where PDAC cells are injected into the pancreas or subcutaneous tissue layer, or genetically engineered animals offer tumors that encompass some stromal component. Herein, we report generation of a simple 3D PDAC in vitro micro-tumor model without an addition of external extracellular matrix, which encompasses a rich, dense and active stromal compartment. We have achieved this in vitro model by incorporating PSCs into 3D PDAC cell culture using a modified hanging drop method. It is now known that PSCs are the principal source of fibrosis in the stroma and interact closely with cancer cells to create a tumor facilitatory environment that stimulates local and distant tumor growth. The 3D micro-stroma models are highly reproducible with excellent uniformity, which can be used for PDAC-stroma interaction analysis and high throughput automated drug-screening assays. Additionally, the increased expression of collagenous regions means that molecular based perfusion and cytostaticity of gemcitabine is decreased in our Pancreatic adenocarcinoma stroma spheroids (PDAC-SS) model when compared to spheroids grown without PSCs. We believe this model will allow an improved knowledge of PDAC biology and has the potential to provide an insight into pathways that may be therapeutically targeted to inhibit PSC activation, thereby inhibiting the development of fibrosis in PDAC and interrupting PSC-PDAC cell interactions so as to inhibit cancer progression

    CIL security proof for a password-based key exchange

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    Computational Indistinguishability Logic (CIL) is a logic for reasoning about cryptographic primitives in computational model. It is sound for standard model, but also supports reasoning in the random oracle and other idealized models. We illustrate the benefits of CIL by formally proving the security of a Password-Based Key Exchange (PBKE) scheme, which is designed to provide entities communicating over a public network and sharing a short password, under a session key

    Collagen-Binding Nanoparticles: A Scoping Review of Methods and Outcomes

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    (1) Background: Collagen is the main component of the connective tissue, playing an important role in the histological architecture and function of living organisms. Targeted therapy and improved imaging diagnosis can be obtained through collagen-binding nanoparticles that concentrate in the extracellular matrix. (2) Methods: We performed a scoping review of studies that analyzed the binding capacity of collagen-targeting nanoparticles. The search algorithm and inclusion criteria were based on PRISMA and ARRIVE guidelines. (3) Results: Fourteen studies matched all the inclusion criteria. All studies analyzed the distribution of nanoparticles in the collagen matrix, either by using collagen-targeting nanoparticles or by using unmodified ones. Most studies used collagen-binding nanoparticles for vascular research to target sites of endothelial injury, atherosclerotic plaques, or myocardial infarction. Two studies targeted the exposed collagen in models of liver fibrosis. (4) Conclusions: Our review summarizes the current literature on the methods and outcomes of using nanoparticles to target collagen. The studies reveal that there is high applicability for collagen-binding nanoparticles in cardiac or hepatic pathology and they could prove useful for targeted therapy of neoplastic lesions, which show an abundance of stromal collagen
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