33 research outputs found

    Effect of Different Polymerization Methods on the Cytotoxicity of Dental Composites

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    Objectives: The aim of this study was to compare the cytotoxic effects of various dental composites polymerized with two different curing units. Methods: Disc-shaped test samples of composites Filtek Z250, Filtek A110, Filtek P60, Filtek Supreme, and SDI Rok were polymerized using one quartz tungsten halogen (QTH) and one light emitting diode (LED) light curing unit (LCU), namely Optilux 501 (QTH) and Elipar Freelight 2 (LED). L-929 mouse fibroblast cultures (3x104 cells/ml) were incubated with the samples in 96 well culture plates for evaluation after 8, 24, 48, 72 h. At the end of each period, the cells were counted and examined under a light microscope, and a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay was performed. The degree of cytotoxicity for each sample was determined according to the reference value represented by the cells in a control group (a culture without sample). Results: A significant 3 factor interaction occurred among LCUs, composites, and time factors (P<.005). In general, the test materials cured with the LED LCU demonstrated higher cell survival rates when compared with those cured with halogen LCUs. Conclusions: This study shows that polymerization of dental composites with a light emitting diode LCU positively influences the L-929 mouse fibroblast cell viability.PubMe

    Do Resin Cements Alter Action Potentials of Isolated Rat Sciatic Nerve?

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    Objectives: The purpose of this study was to explore the effects dual-cure resin cements on nerve conduction. Methods: Panavia F, RelyX ARC, and Variolink II polymerized either by light-emitting diode (LED) or quartz tungsten halogen (QTH) were used in the study (n=10). The conductance of sciatic nerves of 50 rats were measured before and after contact with the specimens for 1 h. Results: The time-dependent change in nerve conductance and the comparison of LED versus QTH showed that differences between groups are significant (P<.05). For both polymerization techniques, pair-wise comparisons of resin cements showed that the nerve conductance between groups is different (P<.05). RelyX ARC elicited irreversible inhibition of compound action potentials (more than 50% change) and Panavia F and Variolink II polymerized by LED and QTH did not alter nerve conduction beyond physiologic limits. Conclusions: Resin cements may alter nerve conductance and even lead to neurotoxic effects.PubMe

    Ultrasound Can Facilitate Percutaneous Endoscopic Gastrostomy Tube Insertion in the Non-Transilluminated Abdominal Wall

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    Percutaneous endoscopic gastrostomy (PEG), first described in the 1980s, is an enteral nutrition route used for long-term nutrition in patients who cannot be fed by mouth for various reasons but have no gastrointestinal disturbance. It is inserted percutaneously into the stomach with the aid of an endoscope. However, the light of the scope may not be seen in some patients due to certain reasons (obesity, prior operations). In this case, it is not safe to send the needle through the abdominal wall. Ultrasound can facilitate the procedure and also reduce adjacent organ injury

    SeamlessM4T-Massively Multilingual & Multimodal Machine Translation

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    What does it take to create the Babel Fish, a tool that can help individuals translate speech between any two languages? While recent breakthroughs in text-based models have pushed machine translation coverage beyond 200 languages, unified speech-to-speech translation models have yet to achieve similar strides. More specifically, conventional speech-to-speech translation systems rely on cascaded systems that perform translation progressively, putting high-performing unified systems out of reach. To address these gaps, we introduce SeamlessM4T, a single model that supports speech-to-speech translation, speech-to-text translation, text-to-speech translation, text-to-text translation, and automatic speech recognition for up to 100 languages. To build this, we used 1 million hours of open speech audio data to learn self-supervised speech representations with w2v-BERT 2.0. Subsequently, we created a multimodal corpus of automatically aligned speech translations. Filtered and combined with human-labeled and pseudo-labeled data, we developed the first multilingual system capable of translating from and into English for both speech and text. On FLEURS, SeamlessM4T sets a new standard for translations into multiple target languages, achieving an improvement of 20% BLEU over the previous SOTA in direct speech-to-text translation. Compared to strong cascaded models, SeamlessM4T improves the quality of into-English translation by 1.3 BLEU points in speech-to-text and by 2.6 ASR-BLEU points in speech-to-speech. Tested for robustness, our system performs better against background noises and speaker variations in speech-to-text tasks compared to the current SOTA model. Critically, we evaluated SeamlessM4T on gender bias and added toxicity to assess translation safety. Finally, all contributions in this work are open-sourced and accessible at https://github.com/facebookresearch/seamless_communicatio

    Single-stage correction, with extensive pulmonary arterial reconstruction, of a pulmonary arterial sling associated with tetralogy of Fallot

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    Pulmonary arterial sling, rare in itself, is even rarer when associated with tetralogy of Fallot. Successful single-stage correction of this combination, with extensive pulmonary arterial reconstruction, has been reported only occasionally. We describe our experience with an 18 month-old girl, showing that extensive reconstruction of both the pulmonary arteries and the right ventricular Outflow tract can permit single-stage correction in selected patients, resulting in favourable physiology and anatomy

    Lightweight Block Ciphers Revisited: Cryptanalysis of Reduced Round PRESENT and HIGHT

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    Design and analysis of lightweight block ciphers have become more popular due to the fact that the future use of block ciphers in ubiquitous devices is generally assumed to be extensive. In this respect, several lightweight block ciphers are designed, of which PRESENT and HIGHT are two recently proposed ones by Bogdanov et al. and Hong et al. respectively. In this paper, we propose new attacks on PRESENT and HIGHT. Firstly, we present the first related-key cryptanalysis of 128-bit keyed PRESENT by introducing 17-round related-key rectangle attack with time complexity approximately 2 104 memory accesses. Moreover, we further analyze the resistance of HIGHT against impossible differential attacks by mounting new 26-round impossible differential and 31-round related-key impossible differential attacks where the former requires time complexity of 2(119.53) reduced round HIGHT evaluations and the latter is slightly better than exhaustive search
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