38 research outputs found

    Fracture Resistance of computer aided endo-crowns versus conventional endo-supported computer aided full crowns

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    The purpose of the present study was to investigate the fracture resistance of computer aided endo-crowns versus conventional core-supported computer aided full crowns. Ninety human teeth were collected, 30 for each type (maxillary central incisors, maxillary 1st premolars and maxillary 1st molars). Specimens were divided into 3 groups (n=10) according to restoration used: 1) PC: Post-core and crown; 2) NC: Nayyar core and crown and 3) EC: Endo-crown. Each group was further subdivided into 3 subgroups according to the tooth used: I (Incisor), P (Premolar) and M (Molar). For group PC: Fiber post (Radix, Dentsply Maillefer) were cemented using resin cement (Calibra Dual Cure, Denstply Detrey GmbH). For group NC: 3 mm of gutta percha of every canal was removed. For groups PC and NC, after etching and bonding of root-face, transparent core former (Coltène/ Whaledent) was filled with SDR (Smart Dentine Replacement, Dentsply Detrey GmbH) and inverted onto root-face and cured. All specimens were individually scanned and thermocycled for 1000 cycles then submitted to compression test using universal testing machine (Instron 8874; Instron Corp.) Fracture was confirmed by sudden drop in load readings. Subgroup IPC scored the highest mean among group I and subgroup PNC scored the highest mean among group P. One-Way ANOVA detected significant differences among groups I and M with p\u3c 0.05 in I and M groups. Regarding P group, P-value was \u3e 0.05 indicating no significant differences among group. Endocrown showed the highest fracture resistance means in molars, while Nayyar core and crown showed the highest fracture resistance means in premolars. However, post-core and crown revealed the highest fracture resistance means in incisors

    EVALUATION OF AN EXPERIMENTAL SCREW-RETAINED RETRIEVABLE CROWN VERSUS CONVENTIONAL CROWN DESIGN

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    Statement of problem: Removing cemented crowns is usually a complicated procedure that may lead to irreversible damage to the tooth/crown and mostly necessitate remake of crown with added effort for both patient and clinician. Purpose: This in-vitro study evaluated an experimental two-component, screw-retained retrievable crown design in comparison to the conventional design. Materials and methods: A total of 120 extracted maxillary 2nd premolars received root canal treatment and were divided into two groups (n=60 each) according to the crown design they will receive. Gp CC received a threaded modified post, a composite core and a metal coping, while Gp RC received a two-component retrievable crown design. Fracture resistance was assessed by a 90 degrees vertical load to the center of the occlusal surface, using universal testing machine, under a constant crosshead speed of 0.5 mm/min until failure. Microleakage was assessed by placing specimens in methylene blue dye for 12 hours, sectioning the teeth longitudinally, and then examining the sectioned samples under stereomicroscope. Retrievability testing was conducted by 5 prosthodontists who attempted to uncover and unscrew the posts. Data were statistically evaluated using computer software (SPSS version 17; SPSS Inc.). Results: No significant difference between the 2 designs tested regarding microleakage tests (P=.34) whereas the experimental design, was significantly more resistant to fracture and more retrievable than the conventional one (P\u3e.5). Conclusions: The proposed retrievable crown design showed promising results and may be considered as an option to substitute the conventional design. Further studies are needed to confirm that

    Weight bias among health care providers for children in UAE

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    Background: This research looks at weight bias among healthcare providers for children in UAE.Methods: This study was done through self-administered questionnaire. Our targets were health care providers for children working in both governmental and private hospitals in UAE. 198 participants were enrolled in the study after exclusion of invalid questionnaires.Results: While 15.4% of healthcare professions in our study acknowledged practice of weight bias during care of obese children, 52.5% denied and 32.1% are not sure about it. 149 participants (76%) believed that failure of obesity management in children is attributed to their weak willpower and poor commitment. Compared with normal children, overweight/obese children are considered less complaint by 59% of our participants, less active by 78.2%, less willpower by 59.5%, less confident by 73.2% and less intelligent by 17.7%. Finally, 10% of our participants consider treatment of overweight/obesity is a waste of time.Conclusions: This study shows significant weight bias among healthcare profession which can occur unintentionally. Weight bias among health care providers affects the quality of medical care of obese children. Education, training and increasing awareness of weight bias among health care providers in UAE is an initial and essential step to decrease the risk of weight bias which is a significant barrier in management of childhood obesity

    K\u3csub\u3eCa\u3c/sub\u3e2.2 (KCNN2): A Physiologically and Therapeutically Important Potassium Channel

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    One group of the K+ ion channels, the small-conductance Ca2+-activated potassium channels (KCa2.x, also known as SK channels family), is widely expressed in neurons as well as the heart, endothelial cells, etc. They are named small-conductance Ca2+-activated potassium channels (SK channels) due to their comparatively low single-channel conductance of about ~10 pS. These channels are insensitive to changes in membrane potential and are activated solely by rises in the intracellular Ca2+. According to the phylogenic research done on the KCa2.x channels family, there are three channels\u27 subtypes: KCa2.1, KCa2.2, and KCa2.3, which are encoded by KCNN1, KCNN2, and KCNN3 genes, respectively. The KCa2.x channels regulate neuronal excitability and responsiveness to synaptic input patterns. KCa2.x channels inhibit excitatory postsynaptic potentials (EPSPs) in neuronal dendrites and contribute to the medium afterhyperpolarization (mAHP) that follows the action potential bursts. Multiple brain regions, including the hippocampus, express the KCa2.2 channel encoded by the KCNN2 gene on chromosome 5. Of particular interest, rat cerebellar Purkinje cells express KCa2.2 channels, which are crucial for various cellular processes during development and maturation. Patients with a loss-of-function of KCNN2 mutations typically exhibit extrapyramidal symptoms, cerebellar ataxia, motor and language developmental delays, and intellectual disabilities. Studies have revealed that autosomal dominant neurodevelopmental movement disorders resembling rodent symptoms are caused by heterozygous loss-of-function mutations, which are most likely to induce KCNN2 haploinsufficiency. The KCa2.2 channel is a promising drug target for spinocerebellar ataxias (SCAs). SCAs exhibit the dysregulation of firing in cerebellar Purkinje cells which is one of the first signs of pathology. Thus, selective KCa2.2 modulators are promising potential therapeutics for SCAs

    Dermal reaction and bigeminal premature ventricular contractions due to neostigmine: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Neostigmine is a frequently used acetylcholinesterase inhibitor administered to reverse muscular relaxation caused by nondepolarizing neuromuscular relaxants in patients recovering from general anesthesia. Severe allergic reactions and urticaria are rarely reported following the use of neostigmine bromide, and never with methylsulfate-containing drugs. In this case, bigeminal premature ventricular contractions added to urticaria provides a warning about the possibility of a life-threatening situation.</p> <p>Case presentation</p> <p>We report the case of a 23-year-old Persian woman who presented with bigeminal premature ventricular contractions along with urticarial lesions on her arm and trunk as soon as she was administered neostigmine methylsulfate after undergoing a laparoscopy for ectopic pregnancy.</p> <p>Conclusion</p> <p>This case report could be of value not only for anesthesiologists who routinely use neostigmine but also for others who administer the pharmaceutical preparation in other situations. The report presents a rare case of drug reaction following neostigmine use. As a result, one should consider any drug a probable cause of drug reaction. The preparation of resuscitative facilities, therefore, is necessary prior to the prescription of the medication.</p

    An evaluation of membrane properties and process characteristics of a scaled-up pressure retarded osmosis (PRO) process

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    YesThis work presents a systematic evaluation of the membrane and process characteristics of a scaled-up pressure retarded osmosis (PRO). In order to meet pre-defined membrane economic viability ( ≥ 5 W/m2), different operating conditions and design parameters are studied with respect to the increase of the process scale, including the initial flow rates of the draw and feed solution, operating pressure, membrane permeability-selectivity, structural parameter, and the efficiency of the high-pressure pump (HP), energy recovery device (ERD) and hydro-turbine (HT). The numerical results indicate that the performance of the scaled-up PRO process is significantly dependent on the dimensionless flow rate. Furthermore, with the increase of the specific membrane scale, the accumulated solute leakage becomes important. The membrane to achieve the optimal performance moves to the low permeability in order to mitigate the reverse solute permeation. Additionally, the counter-current flow scheme is capable to increase the process performance with a higher permeable and less selectable membrane compared to the co-current flow scheme. Finally, the inefficiencies of the process components move the optimal APD occurring at a higher dimensionless flow rate to reduce the energy losses in the pressurization and at a higher specific membrane scale to increase energy generation

    Translational control of depression-like behavior via phosphorylation of eukaryotic translation initiation factor 4E

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    Translation of mRNA into protein has a fundamental role in neurodevelopment, plasticity, and memory formation; however, its contribution in the pathophysiology of depressive disorders is not fully understood. We investigated the involvement of MNK1/2 (MAPK-interacting serine/threonine-protein kinase 1 and 2) and their target, eIF4E (eukaryotic initiation factor 4E), in depression-like behavior in mice. Mice carrying a mutation in eIF4E for the MNK1/2 phosphorylation site (Ser209Ala, Eif4e ki/ki), the Mnk1/2 double knockout mice (Mnk1/2 -/-), or mice treated with the MNK1/2 inhibitor, cercosporamide, displayed anxiety-and depression-like behaviors, impaired serotonin-induced excitatory synaptic activity in the prefrontal cortex, and diminished firing of the dorsal raphe neurons. In Eif4e ki/ki mice, brain IκBα, was decreased, while the NF-κB target, TNFα was elevated. TNFα inhibition in Eif4e ki/ki mice rescued, whereas TNFα administration to wild-type mice mimicked the depression-like behaviors and 5-HT synaptic deficits. We conclude that eIF4E phosphorylation modulates depression-like behavior through regulation of inflammatory responses

    The evolving SARS-CoV-2 epidemic in Africa: insights from rapidly expanding genomic surveillance

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    Investment in SARS-CoV-2 sequencing in Africa over the past year has led to a major increase in the number of sequences generated, now exceeding 100,000 genomes, used to track the pandemic on the continent. Our results show an increase in the number of African countries able to sequence domestically, and highlight that local sequencing enables faster turnaround time and more regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and shed light on the distinct dispersal dynamics of Variants of Concern, particularly Alpha, Beta, Delta, and Omicron, on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve, while the continent faces many emerging and re-emerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century
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