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GNRA tetraloop-binding receptor interactions are key components in the macromolecular assembly of a variety of functional RNAs. In nature, there is an apparent bias for GAAA/11nt receptor and GYRA/helix interactions, with the former interaction being thermodynamically more stable than the latter. While past in vitro selections allowed isolation of novel GGAA and GUGA receptors, we report herein an in vitro selection that revealed several novel classes of specific GUAA receptors with binding affinities comparable to those from natural GAAA/11nt interactions. These GUAA receptors have structural homology with double-locked bulge RNA modules naturally occurring in ribosomal RNAs. They display mutational robustness that enables exploration of the sequence/phenotypic space associated to GNRA/receptor interactions through epistasis. Their thermodynamic self-assembly fitness landscape is characterized by a rugged neutral network with possible evolutionary trajectories toward natural GNRA/receptor interactions. High throughput sequencing analysis revealed synergetic mutations located away from the tertiary interactions that positively contribute to assembly fitness. Our study suggests that the repertoire of GNRA/receptor interactions is much larger than initially thought from the analysis of natural stable RNA molecules and also provides clues for their evolution towards natural GNRA/receptors.
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RNA/química , Evolução Molecular Direcionada , Modelos Moleculares , Mutagênese , Conformação de Ácido NucleicoRESUMO
Fixed bonded retainers are increasingly being recommended as the only way to ensure long-term stability of an orthodontic treatment result. However, frequent debonding of the fixed bonded retainer is a constant source of frustration for the orthodontist. Bond failure is most commonly attributed to the difficulty encountered in stabilizing the retainer wire in the precise position during the bonding process. This paper presents a clinical approach that makes use of Kansal Separator; a self-secured orthodontic spring separator as a simple, efficient, and dependable fixed retainer stabilizer.
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Colagem Dentária/instrumentação , Contenções Ortodônticas , Humanos , Desenho de Aparelho Ortodôntico , Fios Ortodônticos , Torção MecânicaRESUMO
AIM: Aim of this cross sectional study was to compare the bite force and the individual tooth load among three groups of patients: cases finished with the Self ligation appliance (Damon-Q®, 0.022"X0.028" prescription) cases finished with the MBT (McLaughlin, Bennett and Trevisi) appliance system (0.022"X0.028"prescription) and orthodontically untreated cases using T-Scan® 9.0 version. MATERIAL & METHODS: A sample size of sixty non-extraction cases were divided equally into three groups - Group 1: patients treated with Self-ligation appliance (Damon Q®), Group 2: cases treated with the MBT prescription and Group 3: untreated subjects with Class I canine and molar relationship who were used as the control group. The bite force and distribution of force was measured on the right and left side as well as individual tooth loads were measured using the T-Scan® 9.0 device and inter-and intra-group comparisons made using Paired t-Test, ANOVA and Chi-square test. RESULT: The bite forces were balanced on both the sides in cases treated with Self-ligation and MBT appliance. The Self-ligation finishes were marginally better than the MBT group but the difference was statistically insignificant. CONCLUSION: Orthodontically treated individuals had a better (or more even) bite force distribution compared to untreated participants.
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BACKGROUND: The COVID-19 pandemic has made dentists very assiduous about cross-infection during dental treatment, thereby delaying dental radiographs for treatment. However, patients needing dental emergency treatment in the ongoing pandemic require relevant intra/extraoral dental radiography for adequate diagnosis and treatment planning. METHODS: This article is aimed at adding to the hot debate: Is delay for intraoral radiographs justified or a possible proxy? As a narrative review, it provides an insight into the reasons for delaying intra-oral dental radiographs during in the pandemic and options of the nontraditional radiographic techniques available until the pandemic subsides. Discussion and Conclusion. Cross-contamination concerns through respiratory droplets grow while using intraoral film holders that stimulate gag reflex, coughing, saliva secretion, and if proper disinfection protocols are not applied. Since the patients' acquiring emergency dental treatment cannot be neglected, the return-to-work guidelines by the health regulatory bodies urge to prioritize extraoral radiographic imaging techniques to curb the infection, offering the best diagnostic efficacy. The dental professionals can consider cone-beam computed tomography (CBCT) scans and sectional dental panoramic radiographs (SDPRs), followed by a risk assessment for COVID-19, a safer modality in reducing cross-contamination and assuring an innocuous environment for both patient and coworkers.
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COVID-19 , Radiografia Dentária/métodos , COVID-19/epidemiologia , Tomografia Computadorizada de Feixe Cônico , Humanos , Pandemias , Planejamento de Assistência ao Paciente , Radiografia Dentária Digital/métodos , Radiografia Panorâmica , Tempo para o TratamentoAssuntos
Incisivo/anormalidades , Procedimentos de Ancoragem Ortodôntica , Técnicas de Movimentação Dentária , Parafusos Ósseos , Arco Dental/anormalidades , Feminino , Humanos , Procedimentos de Ancoragem Ortodôntica/instrumentação , Procedimentos de Ancoragem Ortodôntica/métodos , Técnicas de Movimentação Dentária/instrumentação , Técnicas de Movimentação Dentária/métodos , Adulto JovemRESUMO
PURPOSE: PaO2 to FiO2 ratio (P/F) is used to assess the degree of hypoxemia adjusted for oxygen requirements. The Berlin definition of Acute Respiratory Distress Syndrome (ARDS) includes P/F as a diagnostic criterion. P/F is invasive and cost-prohibitive for resource-limited settings. SaO2/FiO2 (S/F) ratio has the advantages of being easy to calculate, noninvasive, continuous, cost-effective, and reliable, as well as lower infection exposure potential for staff, and avoids iatrogenic anemia. Previous work suggests that the SaO2/FiO2 ratio (S/F) correlates with P/F and can be used as a surrogate in ARDS. Quantitative correlation between S/F and P/F has been verified, but the data for the relative predictive ability for ICU mortality remains in question. We hypothesize that S/F is noninferior to P/F as a predictive feature for ICU mortality. Using a machine-learning approach, we hope to demonstrate the relative mortality predictive capacities of S/F and P/F. METHODS: We extracted data from the eICU Collaborative Research Database. The features age, gender, SaO2, PaO2, FIO2, admission diagnosis, Apache IV, mechanical ventilation (MV), and ICU mortality were extracted. Mortality was the dependent variable for our prediction models. Exploratory data analysis was performed in Python. Missing data was imputed with Sklearn Iterative Imputer. Random assignment of all the encounters, 80% to the training (n = 26690) and 20% to testing (n = 6741), was stratified by positive and negative classes to ensure a balanced distribution. We scaled the data using the Sklearn Standard Scaler. Categorical values were encoded using Target Encoding. We used a gradient boosting decision tree algorithm variant called XGBoost as our model. Model hyperparameters were tuned using the Sklearn RandomizedSearchCV with tenfold cross-validation. We used AUC as our metric for model performance. Feature importance was assessed using SHAP, ELI5 (permutation importance), and a built-in XGBoost feature importance method. We constructed partial dependence plots to illustrate the relationship between mortality probability and S/F values. RESULTS: The XGBoost hyperparameter optimized model had an AUC score of .85 on the test set. The hyperparameters selected to train the final models were as follows: colsample_bytree of 0.8, gamma of 1, max_depth of 3, subsample of 1, min_child_weight of 10, and scale_pos_weight of 3. The SHAP, ELI5, and XGBoost feature importance analysis demonstrates that the S/F ratio ranks as the strongest predictor for mortality amongst the physiologic variables. The partial dependence plots illustrate that mortality rises significantly above S/F values of 200. CONCLUSION: S/F was a stronger predictor of mortality than P/F based upon feature importance evaluation of our data. Our study is hypothesis-generating and a prospective evaluation is warranted. Take-Home Points. S/F ratio is a noninvasive continuous method of measuring hypoxemia as compared to P/F ratio. Our study shows that the S/F ratio is a better predictor of mortality than the more widely used P/F ratio to monitor and manage hypoxemia.
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BACKGROUND: The present study aimed to determine the correlation between pharyngeal airway volume and craniofacial morphology through cone-beam computed tomography (CBCT). Additionally, the study analyzed the influence of gender on pharyngeal airway volume. (2) Methods: 80 CBCT scans of 40 male and 40 female patients (mean age: 15.38 + 1.10 years) fulfilling the eligibility criteria were included. CBCT scans were evaluated for pharyngeal airway volume using the In Vivo Dental 5.1 software. Additionally, CBCT-derived lateral cephalograms were used to assess various craniofacial morphology parameters. To examine the influences of gender on airway volume, T-test was carried out. Correlation between airway volume and craniofacial parameters were measured using Pearson correlation followed by regression analysis. The value of p < 0.05 was considered statistically significant. RESULTS: The mean airway volume was significantly greater in males than in females. A statistically significant negative correlation was found between maxillary plane inclination and pharyngeal airway volume. In contrast, a positive correlation was observed between mandibular length and lower molar inclination with oropharyngeal and total pharyngeal airway volume. Females showed a statistically significant positive correlation between the pharyngeal airway volume and sagittal position of maxilla and mandible; they also showed a negative correlation between oropharyngeal airway volume and the mandibular plane angle. CONCLUSIONS: Overall, the pharyngeal airway space differs significantly between males and females. Craniofacial morphology does have a significant effect on the pharyngeal airway, especially on the oropharyngeal airway volume.
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Tomografia Computadorizada de Feixe Cônico Espiral , Adolescente , Cefalometria , Tomografia Computadorizada de Feixe Cônico , Feminino , Humanos , Imageamento Tridimensional , Masculino , Projetos Piloto , Estudos RetrospectivosRESUMO
OBJECTIVE: The aim of this study was to assess & compare the changes in cytokine levels in GCF samples of patients wearing clear aligners. METHODS: GCF samples of 10 patients undergoing orthodontic treatment, for correction of lower anterior crowding with clear aligners, were collected on day 0, 1, 3, 7 and 21 using periopaper strips. The upper arch was taken as the control site. The samples collected were further analyzed using commercially available ELISA based kits. RESULTS: The mean levels of IL-1ß at day 0, 1, 3, 7 and 21 were compared between experimental and control sites using unpaired t-test and it was found that the levels of IL-1ß were significantly elevated on experimental site in comparison to control site. CONCLUSION: It was concluded from the study that elevation in levels of IL-1ß as a biomarker of orthodontic tooth movement reaches its peak after 24 h of force application. The clear aligners, as an alternative to conventional fixed orthodontic treatment, were found to be efficient in correcting mild to moderate lower arch crowding.
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Pressure-regulated volume control (PRVC) is a mode of ventilation in which the ventilator attempts to achieve set tidal volume at lowest possible airway pressure. This mode of ventilation is being commonly used as the initial mode of ventilation in many intensive care units. We describe two cases where this adaptive mode of ventilation became maladaptive leading to patient-ventilator dyssynchrony.
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This article is a rumination on the outbreak of the dreaded coronavirus disease-2019 (COVID-19) pandemic which has engulfed both the developed and the developing countries, thereby causing widespread global public health concerns and threats to human lives. Although countries have made varied efforts, the pestilence is escalating due to the high infectivity. It is highly likely that dental professionals in upcoming days will come across COVID-19 patients and SARS-CoV-2 carriers, and hence must ensure a tactful handling of such patients to prevent its nosocomial spread. Despite the avalanche of information that has exploded in relation to this rapidly spreading disease, there is a lack of consolidated information to guide dentists regarding clinical management including precautions to take materials to use and postprocedure care, during and after the COVID-19 pandemic. Available sources of information have been analyzed, while relying on peer-reviewed reports followed by information available from the most respected authoritative sources, such as WHO, Centers for Disease Control and Prevention (CDC), and ADA. This review aims to provide a comprehensive summary from the available literature on COVID-19, its insinuation in dentistry, recommendations that have been published, and the actual in-practice implications, so a plan can be formulated and adapted to the circumstances of each dental practice during the pandemic and the times to follow. HOW TO CITE THIS ARTICLE: Kochhar AS, Bhasin R, Kochhar GK, et al . Dentistry during and after COVID-19 Pandemic: Pediatric Considerations. Int J Clin Pediatr Dent 2020;13(4):399-406.
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INTRODUCTION: The esoteric Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) infection or COVID-19 has been an unusual plummet in dental/orthodontic practice. Based on current recommendations for various amendments in an orthodontic practice, this scoping review aims to identify orthodontic appliances that are most appropriate to us during this on-going pandemic. METHODS: Electronic databases (PubMed, Scopus, Web of Science, Science Direct, and Google Scholar) were searched up until August 11, 2020. Full-text articles in English with keywords "COVID-19 and Orthodontics" and related search terms were included. RESULTS: Out of 17 retracted articles, only 4 articles were found to be brief the choice for orthodontic appliances in pandemic times speculating clear aligner therapy (CAT) to be a pragmatic solution. The remaining articles were also thoroughly studied and the new norms set by the pandemic were determined. Criteria for orthodontic appliance selection included careful patient screening and collection of records, minimal physical visits, efficient use of technology, virtual consultations but the use of PPE for physical appointments; and lesser AGPs with a lesser risk of airborne transmission. CONCLUSIONS: Subject to regional demands, CAT can be considered as the relatively safer modality-predictable and effective apposite to fixed orthodontic appliances in these unprecedented times.
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Hypotonic hyponatremia is a common electrolyte disorder defined by a blood serum sodium value of less than 136 meq/L. A challenge in managing hyponatremia is accurately determining the etiology for the free water excess as management can markedly differ. Accurate diagnosis of the etiology of hypotonic hyponatremia requires precision in the determination of extracellular volume status. Determination of volume status has traditionally relied on physical examination, imaging modalities, and clinical gestalt, all of which are inaccurate. Portal vein pulsatility is an easy to perform bedside ultrasound imaging study which can be used as a marker for hypervolemia and venous congestion. We present 2 cases of hypervolemic hyponatremia in which portal vein pulsatility was used in the diagnosis and management and as a marker for efficacy of treatment.
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The intensive care unit (ICU) is an incredibly complex environment, and ICU rounds are mentally taxing. The cognitive biases that tend to arise in mentally taxing environments such as the ICU pose a risk to patients. This review discusses 10 common cognitive biases and logical fallacies using examples in Nephrology Critical Care. Our objective is to promote metacognition (i.e., an awareness of one's cognition) among physicians. A state of metacognition is not a panacea, but aspiring for metacognition allows the critical care physician to improve chances for optimal patient outcomes.
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OBJECTIVE: The objective of this clinical study was to assess the predicted software models and clinical models and to compare the stage models of both the groups so as to evaluate the efficacy of tooth movement with clear aligner. METHODS: The sample size included 10 cases with mild anterior crowding treated with aligner therapy. The predicted software models were superimposed on the clinical stereolithography (STL) models at various stages by using the MeshLab software. The predicted software models showing orthodontic tooth movement were compared with the actual movement achieved clinically. RESULTS: The results of the present study have shown that when a comparison was made on the basis of irregularity scores in both the groups, it was seen that the irregularity score was higher at 2.55 at T4, 1.65 at T6, and 1.0 at T8 in the clinical STL group at each stage, whereas it was 2.0 at T4, 0.90 at T6, and 0.25 at T8 in the software model group. In addition, in comparing the mean accuracy of these three stages, the analysis of data showed that the mean accuracy is 62.5% at T4, 68.8% at T6, and 78.1% at T8. CONCLUSION: The predicted software models do not accurately reflect the patient's tooth position. There is an overestimation by predicted software as compared with actual clinically achieved tooth position. There is a need of overcorrection to be built in the treatment planning stage itself and execution of the anticipated end result.
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Early stage acute kidney injury (AKI) is an independent risk factor for an increase in mortality. Accurate assessment of volume status is a major challenge during the early stages of acute renal injury. Determining volume status based on the history and physical exam lacks accuracy. Urine sodium and free excretion of sodium (FENa) provide objective evidence of intravascular volume status when interpreted carefully and is helpful to delineate prerenal from intrinsic renal failure. In recent years point of care ultrasound has been used to assess volume status. Our team conducted a retrospective chart review to assess the association of inferior vena cava collapsibility by point of care ultrasound (POCUS) and urine electrolytes (urine sodium, fractional excretion of sodium) during early stage AKI (Stage 1-2 of KDIGO guidelines). We reviewed 150 cases based on the provisional diagnosis. 36 patients met the criteria for further review. Using bivariate analysis, we found a strong association between >50% IVC collapsibility with FENa < 0.4% with an odds ratio 5.3 (CI 1.1-24.5, p = 0.04), and urine sodium <20 meq/dl with an odds ratio of 6.7 (Cl 1.5-30, p = 0.02). Subsequently, multivariate analysis and Spearman correlation showed an inverse relation between IVC collapsibility and fractional excretion of sodium FENa (ß = -0.4, p = 0.001) and (r = -0.44, p = 0.01). These findings suggest the role of POCUS and urinary markers in determining the intravascular volume status in AKI. POCUS is also valuable to assess volume status in cases of renal failure where urine studies are difficult to interpret.
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We report a case of a 25-year-old obese, currently smoking, female diagnosed with EBV infectious mononucleosis. The patient complained of sudden onset abdominal pain with progressively increasing intensity in the left upper quadrant. Abdominal CT scan showed a wedge infarct of the spleen. We present this rare case that EBV may cause splenic infarct in young adults.
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Pneumatosis intestinalis is a radiographic finding that represents a spectrum of conditions ranging from benign disease to abdominal sepsis and death. Along with portal venous gas, it is generally considered an ominous sign prompting emergency operative intervention. We report a rare case showing that nonoperative therapy can be considered in a seriously ill patient with esophageal, gastric and portal venous air.
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Leptospirosis is a rare zoonotic disease which occurs in people exposed to contaminated water or/and animal urine. We report two cases of moderate to severe leptospirosis. The first case was a healthy middle-aged biology professor who recently visited his family in Jamaica and presented with multi-organ failure. The second case was a 27-year-old police officer who was admitted for acute liver injury and thrombocytopenia after helping people evacuate during a flood/disaster situation.