Ultranarrow heterojunctions of armchair-graphene nanoribbons as resonant-tunnelling devices.

A systematic investigation is performed on the electronic transport properties of armchair-graphene nanoribbon (AGNR) heterojunctions using spin-polarized density functional theory calculations in combination with the non-equilibrium Green's function formalism. 9-AGNR and 5-AGNR structures are used to form a single-well configuration by sandwiching a 5-AGNR between two 9-AGNRs. At the same time, these 9-AGNRs are matched at the left and right to electrodes, 9 and 5 being the number of carbon dimers as width. This heterojunction mimics an electronic device with two potential barriers (9-AGNR) and one quantum well (5-AGNR) where quasi-bound states are confined. First, we study the ground state properties, and then we calculate the electron transport properties of this device as a function of the well width. We show the presence of electronic tunnelling resonances between the barriers by delocalized electron density inside the well's structure. This is corroborated by transmission curves, localized densities of states (LDOS), current-vs.-bias voltage results, and the trend of the resonances as a function of the well width. This work shows that carbon AGNRs may be used as resonant-tunnelling devices for applications in nanoelectronics.

Analysis of the sleep period and the amount of habitual snoring in individuals with sleep bruxism.

BACKGROUND: The literature does not report any association between habitual snoring and sleep bruxism, but these situations can be a reason for frequent complaints of individuals, impairing the quality of life. This study was performed to investigate the sleep period and amount of habitual snoring in individuals with sleep bruxism observing expiratory, inspiratory, and mixed snoring. MATERIAL AND METHODS: A total of 90 individuals were screened and divided into the following groups: with sleep bruxism (n=45) and those without sleep bruxism (n=45). Single night sleep polysomnography was performed to diagnose sleep bruxism, quantify habitual snoring and sleep period. The results were tabulated and submitted to a Multivariate analysis of variance (MANOVA) to compare the means of the two independent groups, considering the affected diagnosis of sleep bruxism, snoring (independent variables) and age as covariate. For the post hoc, was used correcting for multiple comparisons (Bonferroni test, P<.05). RESULTS: There was statistically significant difference among the groups ( p=.001) in the sleep period, in that individuals with sleep bruxism slept for a longer duration (with sleep bruxism group: 460 minutes and without sleep bruxism group: 401 minutes). There were no statistically significant differences among the groups for the number of inspiratory, expiratory and mixed snores, but was observed greater amount of snoring in the with sleep bruxism group. CONCLUSIONS: The main finding of this study is that individuals with sleep bruxism slept longer than the control group. It may also be suggested that individuals with sleep bruxism tended to increase the amount of habitual snoring during sleep.

Influence of sleep bruxism severity on masticatory efficiency: electromyographic analysis.

The objective of the present study was to ascertain masticatory efficiency by evaluating electromyographic activity in the masseter and temporalis muscles in subjects with sleep bruxism of varying severity, as determined by BiteStrip. Thirty-four subjects with sleep bruxism were divided into two groups: a mild sleep bruxism group with a mean (± standard deviation) age of 31.3 ± 6.2 years (n = 15) and a severe sleep bruxism group with a mean age of 29.8 ± 7.1 years (n = 19). Full-night polysomnography (PSG) was performed in eligible subjects. The linear envelope integral was used to determine masticatory efficiency on the basis of the electromyographic signal of the masseter and temporalis muscles during habitual and non-habitual chewing. There was significantly higher (p .05) electromyographic activity in the severe bruxism group than in the mild bruxism group during both peanut chewing in the right (p = .03) and left (p = .03) temporalis muscles and raisin chewing in the right (p = .01) and left (p = .05) temporalis muscles. Furthermore, Parafilm M chewing showed similar results in the right (p = .008) and left (p = .02) temporalis muscles. These results suggested that subjects with severe sleep bruxism had lower masticatory efficiency.

Specific immunotherapy in local allergic rhinitis: A randomized, double-blind placebo-controlled trial with Phleum pratense subcutaneous allergen immunotherapy.

BACKGROUND: Allergen immunotherapy has been shown to be an effective treatment for local allergic rhinitis (LAR) to house dust mites. Studies with pollen allergen immunotherapy are limited to observational studies. The aim of this study was to evaluate the clinical efficacy and safety of Phleum pratense subcutaneous immunotherapy (Phl-SCIT) in LAR. METHODS: In a randomized double-blind placebo-controlled study, 56 patients with moderate-severe LAR to grass pollen received Phl-SCIT with a depigmented polymerized pollen vaccine or placebo for the first year, and Phl-SCIT the second one. The blind was maintained throughout the study. Primary outcome was combined symptom medication score (CSMS) during grass pollen season (GPS). Secondary clinical outcomes included organ-specific symptoms, medication-free days, rhinitis severity and asthma control. Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), nasal allergen provocation test (NAPT), skin testing, serum levels of specific IgG4 and specific IgE and safety were also evaluated. RESULTS: Subcutaneous immunotherapy (SCIT) had a short-term and sustained effect with significant improvements of all primary and secondary clinical outcomes and RQLQ score. SCIT significantly increased serum sIgG4 levels and allergen tolerance, from the 6th to 24th months of treatment. At the end of the study, 83% of patients treated with ≥6 months of SCIT tolerated a concentration of P. pratense over 50 times higher than baseline, and 56% gave a negative NAPT. SCIT was well tolerated; six mild local reactions occurred, and there were no serious adverse events related to the study medication. CONCLUSIONS: Subcutaneous immunotherapy with depigmented polymerized allergen extracts is a safe and clinically effective treatment for LAR to P. pratense.

Technical quality of root canal treatment performed by undergraduate students using hand instrumentation: a meta-analysis.

The technical quality of root canal treatment (RCT) may impact on the outcome. The quality of education received during undergraduate school may be linked to the quality of treatment provided in general dental practice. In this context, the aim of this systematic review was to answer the following focused questions: (i) What is the frequency of acceptable technical quality of root fillings, assessed radiographically, performed by undergraduate students? (ii) What are the most common errors assessed radiographically and reported in these treatments? For this purpose, articles that evaluated the quality of root fillings performed by undergraduate students were selected. Data were collected based on predetermined criteria. The key features from the included studies were extracted. GRADE-tool assessed the quality of the evidence. MAStARI evaluated the methodological quality, and a meta-analysis on all studies was conducted. At the end of the screening, 24 articles were identified. Overall frequency of acceptable technical quality of root fillings was 48%. From this total, 52% related to anterior teeth, 49% to premolars and 26% to molars. The main procedural errors reported were ledge formation, furcation perforation, apical transportation and apical perforation. The heterogeneity amongst the studies was high (84-99%). Five studies had a high risk of bias, eight had a moderate risk, and 11 had low risk. The overall quality of evidence identified was very low. The conclusion was that technical quality of root fillings performed by undergraduate students is low, which may reveal that endodontic education has limited achievement at undergraduate level. A plan to improve the quality of root fillings, and by extrapolation the overall quality of root canal treatment, should be discussed by the staff responsible for endodontic education and training.

Effects of glucosamine supplements on painful temporomandibular joint osteoarthritis: A systematic review.

The purpose of this study was to systematically review the literature for studies that assessed the effects of glucosamine supplements (GS) on pain and maximum mouth opening (MMO) restriction compared to other therapies, placebo or no intervention on painful temporomandibular joint osteoarthritis (TMJ OA). Randomised controlled trials were selected in a two-phase process. Seven electronic databases, in addition to three grey literature databases, were searched. Risk of bias was assessed using the Cochrane Collaboration's tool for assessing risk of bias in randomised trials. Twelve potentially eligible studies were identified, from which three were finally included. Furthermore, two were categorised at low risk and one at high risk of bias. Intervention groups were treated with glucosamine-sulphate, while controls were treated with placebo or ibuprofen. In two studies, GS were equally effective regarding pain reduction and mouth opening improvement compared to ibuprofen taken two or three times a day over 12 weeks; however, one study did not find significant differences in follow-up evaluations concerning these clinical variables in both glucosamine and placebo groups administered over six weeks. There is very low evidence regarding GS therapeutic effects on TMJ OA. Considering a follow-up of 12 weeks, GS were as effective as ibuprofen taken two or three times a day. However, over six weeks of medication intake, GS were not superior to placebo. Still, included studies presented major drawbacks, and therefore, conclusions must be interpreted with caution.

Association between chewing dysfunctions and temporomandibular disorders: A systematic review.

Temporomandibular disorder (TMD) is an umbrella condition presenting several signs and symptoms including pain in the temporomandibular joint (TMJ) and masticatory muscles, articular noises, earache, headache, irregular or restricted jaw function, chewing difficulty, and limited mouth opening. Such TMD impairment may cause disorders during the chewing process. Therefore, the purpose of this systematic review was to assess chewing dysfunctions measured by sEMG, and their association with TMD. A combination and variation in the descriptors "temporomandibular joint disorders", "masticatory dysfunctions", and electromyography were used to perform the searches across databases. The databases chosen were: LILACS, PubMed, Science Direct, Scopus, and Web of Science. Additionally, grey literature was assessed using Google Scholar, ProQuest, and OpenGrey. Studies in adults that diagnosed TMD through the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD), Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) or Helkimo Protocol were selected. Furthermore, those studies should have evaluated chewing processes through surface electromyography (sEMG). Risk of bias of the included studies was assessed through the Meta-Analysis of Statistics Assessment and Review Instrument (MAStARI) tool. Eleven included studies shown significant results; however, they evaluated discrepant parameters, presented high inconsistency in the application, and had chosen different tasks to analyse the sEMG and hence, there was no consensus in the results of studies. In conclusion, strength of recommendations was very low due to a series of limitations on studies and it was not possible to made categorical statement about association between TMD and chewing dysfunctions in adults when parameters of sEMG were analysed.

Association between psychotropic medications and presence of sleep bruxism: A systematic review.

The purpose of this study was to systematically review the literature for studies that investigated the association between use of psychotropic medications and presence of sleep bruxism (SB). Observational studies were selected in a two-phase process. Searches were performed on six electronic databases, and a grey literature search was conducted on three databases. SB diagnosis was based on questionnaires or clinical examinations; no polysomnography examinations were performed. Risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Analytical Cross-Sectional Studies. Overall quality of evidence was evaluated according to the Grading of Recommendations Assessment, Development and Evaluation criteria. Five analytical cross-sectional studies were included, evaluating antidepressants, anticonvulsants and psychostimulants. One study was judged as low risk of bias, three as moderate risk and one high risk. Antidepressants were evaluated in adult populations only; duloxetine (Odds Ratio [OR] = 2.16; 95% Confidence Interval [95% CI] = 1.12-4.17), paroxetine (OR = 3.63; 95% CI = 2.15-6.13) and venlafaxine (OR = 2.28; 95% CI = 1.34-3.86) were positively associated with SB risk. No increased odds of SB were observed considering use of citalopram, escitalopram, fluoxetine, mirtazapine and sertraline. With regard to anticonvulsants, only barbiturates were associated with SB in children (OR = 14.70; 95% CI = 1.85-116.90), while no increased odds were observed for benzodiazepine, carbamazepine and valproate. The only psychostimulant evaluated was methylphenidate, and an association with SB was observed in adolescents (OR = 1.67; 95% CI = 1.03-2.68). Findings from this SR suggested that medications such as duloxetine, paroxetine, venlafaxine, barbiturates and methylphenidate might be associated with SB; however, overall quality of evidence was considered very low, and therefore, caution is recommended.

Immediate Reactions to More Than 1 NSAID Must Not Be Considered Cross-Hypersensitivity Unless Tolerance to ASA Is Verified.

BACKGROUND AND OBJECTIVES: Individuals who develop drug hypersensitivity reactions (DHRs) to chemically unrelated nonsteroidal anti-inflammatory drugs (NSAIDs) are considered cross-hypersensitive. The hallmark for this classification is that the patient presents a reaction after intake of or challenge with acetylsalicylic acid (ASA). Whether patients react to 2 or more NSAIDs while tolerating ASA remains to be studied (selective reactions, SRs). Objective: To identify patients with SRs to 2 or more NSAIDs including strong COX-1 inhibitors. METHODS: Patients who attended the Allergy Service of Hospital Infanta Leonor, Madrid, Spain with DHRs to NSAIDs between January 2011 and December 2014 were evaluated. Those with 2 or more immediate reactions occurring in less than 1 hour after intake were included. After confirming tolerance to ASA, the selectivity of the response to 2 or more NSAIDs was demonstrated by in vivo and/or in vitro testing or by controlled administration. RESULTS: From a total of 203 patients with immediate DHRs to NSAIDs, 16 (7.9%) met the inclusion criteria. The patients presented a total of 68 anaphylactic or cutaneous reactions (mean [SD], 4.2 [2.1]). Most reactions were to ibuprofen and other arylpropionic acid derivatives and to metamizole. Two different NSAIDs were involved in 11 patients and 3 in 5 patients. CONCLUSIONS: Patients with NSAID-induced anaphylaxis or urticaria/angioedema should not be considered cross-hypersensitive unless tolerance to ASA is verified.

Validity of different tools to assess sleep bruxism: a meta-analysis.

This systematic review and meta-analysis (MA) aimed to evaluate the diagnostic validity of questionnaires, clinical assessment and portable diagnostic devices compared to the reference standard method polysomnography (PSG) in assessing sleep bruxism (SB). Two reviewers searched electronic databases for diagnostic test accuracy studies that compared questionnaires, clinical assessment or portable diagnostic devices for SB, with the reference standard method PSG, comprising previous studies from all languages and with no restrictions regarding age, gender or time of publication. Of the 351 articles, eight met the inclusion criteria for qualitative, and seven for quantitative analysis. The methodology of selected studies was evaluated using the Quality Assessment Tool for Diagnostic Accuracy Studies (QUADAS-2). The studies were divided and analysed over three groups: three studies evaluating questionnaires, two regarding the clinical assessment of tooth wear and three covering portable diagnostic devices. The MA indicated that portable diagnostic devices showed the best validity of all evaluated methods, especially as far as a four-channel EMG/ECG recording is concerned. Questionnaires and the clinical assessment can be used as screening methods to identify non-SB individuals, although it is not that good in identifying subjects with SB. The quality of evidence identified through GRADEpro, was from very low-to-moderate, due to statistical heterogeneity between studies.

A non-synonymous polymorphism in galectin-3 lectin domain is associated with allergic reactions to beta-lactam antibiotics.

Genetic predictors of beta-lactam (BL) allergy are mostly related to Immunoglobulin E (IgE) synthesis and atopy. Despite this context, little attention has been devoted to genes of IgE/FcɛRI pathway, such as galectin-3, a ß-galactoside-binding lectin, which binds to IgE. We evaluated the association of LGALS3 polymorphisms with BL allergy in 395 Spanish and 198 Italian cases, compared with 310- and 339-matched controls, respectively. The rs11125 predicted BL allergy with an odds ratio of 4.0 in Spanish population (P<0.0001). This association was replicated with an odds ratio of 5.1 in Italian population (P<0.0001); rs11125 predicted also increased serum level of total IgE in Spanish controls. These data are consistent with the predicted deleterious influence of Gln>His substitution produced by rs11125 on galactose-binding activity of galectin-3. In conclusion, LGALS3 is the strongest genetic predictor of BL allergy reported so far. This association reflects the influence of genes of IgE/FcɛRI pathway in this pathology.

Immediate hypersensitivity reactions to ibuprofen and other arylpropionic acid derivatives.

BACKGROUND: Although ibuprofen and other arylpropionic acid derivatives (APs) are the most common medicines involved in hypersensitivity drug reactions (HDRs) to NSAIDs, no patient series studies have been performed regarding immediate selective reactions (SRs) to these drugs. OBJECTIVE: To characterize patients with immediate selective HDRs to ibuprofen and other APs through clinical history and challenge. METHODS: Subjects who developed an HDR to APs less than 1 h after drug intake were included. Tolerance to aspirin was assessed and challenge was performed with ibuprofen in all cases, and additionally with the culprit drug (if different) in those patients that tolerated ibuprofen. Serum tryptase levels and tryptase immunohistochemical staining in skin biopsies were also assessed in some patients with a positive DPT to ibuprofen. RESULTS: From a total of 245 patients with a confirmed history of HDRs to APs, 17% were classified as selective immediate hypersensitivity reactors by both clinical history and challenge. A selective response to naproxen and dexketoprofen with tolerance to ibuprofen was found in 16 of 20 cases. Significant differences in serum tryptase levels were observed between 2 and 24 h in the 11 cases that were studied further. CONCLUSIONS: Within the group of patients with HDRs to NSAIDs, APs can induce immediate SRs. Within this group, selective responses to a single drug or responders to several APs may exist, suggesting potential immunological cross-reactivity.

The Genetics of Drug Hypersensitivity Reactions.

DHRs are induced by various mechanisms and encompass a heterogeneous set of potentially life-threatening clinical entities. In addition to environmental effects, individual factors play a key role in this intricate puzzle. However, despite commendable efforts in recent years to identify individual predisposing factors, our knowledge of the genetic basis of these reactions remains incomplete. In this manuscript, we summarize current research on the genetics of DHRs, focusing on specific immune-mediated reactions (immediate and nonimmediate) and on pharmacologically mediated reactions (cross-intolerance to nonsteroidal anti-inflammatory drugs). We also provide some thoughts on potential technological approaches that would help us to decipher the molecular mechanisms underlying DHRs. We believe this manuscript will be of interest not only for allergists and basic researchers in the field, but also for clinicians from various areas of expertise who manage these reactions in their clinical practice.

Seasonal Local Allergic Rhinitis in Areas With High Concentrations of Grass Pollen.

BACKGROUND: Local allergic rhinitis (LAR) is a phenotype of allergic rhinitis characterized by the presence of a localized immune response in the nasal mucosa of patients with negative skin prick test (SPT) results and undetectable serum specific IgE (sIgE). It unknown whether LAR is limited to areas with low or moderate aeroallergen exposure. OBJECTIVE: To explore the presence of LAR and the clinical and immunological characteristics of this entity in geographic areas with high grass pollen loads. METHODS: A cross-sectional observational study was carried out in 2 hospitals in central Spain (Madrid and Ciudad Real). Sixty-one patients with seasonal rhinitis and negative SPT results and undetectable serum sIgE were evaluated using a clinical questionnaire, determination of serum total IgE, and a nasal allergen provocation test (NAPT) with Phleum species. The response to NAPT was monitored using assessment of nasal symptoms, acoustic rhinometry, and determination of sIgE, tryptase, and eosinophil cationic protein in the nasal cavity. RESULTS: Seasonal LAR was detected in 37 patients (61%) using the techniques described above. Eleven percent of patients with LAR were adolescents or children, and 14% reported onset of rhinitis in childhood. Most patients reported persistent-moderate seasonal nasal symptoms, and 41% reported worsening of the disease during the last 2 years. Conjunctivitis was the most common comorbidity, affecting 95% of cases. CONCLUSIONS: LAR to grass pollen is relevant in patients with seasonal symptoms indicative of allergic rhinitis but with a negative skin test result who live in areas with high allergenic pollen loads. This entity should be included the differential diagnosis of rhinitis.

Effect of temporomandibular disorder therapy on otologic signs and symptoms: a systematic review.

The most common temporomandibular disorders (TMD) signs and symptoms are related to muscle sensitivity through palpation, restricted mouth opening, asymmetric mandibular movements, joint sounds, pain and otologic signs and symptoms. To date, counselling, occlusal splints, exercises, biofeedback and acupuncture are examples of conservative modalities proposed for TMD therapy. The aim of this systematic review was to investigate the effect of these conservative therapies for TMD on otologic signs and symptoms. The authors searched the following electronic databases published up to 1st May 2015: PubMed, LILACS, Scopus, Web of Science and Science Direct with no time or language limitations. Using a two-phase selection process, the authors identified 08 articles and used them to conduct a qualitative analysis. Methodological quality of each article was performed with the aid of 'Quality Assessment of a Cohort Study' and 'Quality Assessment of a Randomized Clinical Trial', developed by the Dutch Cochrane Centre, a centre of the Cochrane Collaboration. This systematic review showed in seven of the eight studies included that a total or partial resolution of otologic complains occurred after counselling, exercise therapies and occlusal splint therapy. Upon the limitations of the studies included in this systematic review, the present outcomes suggested that there is insufficient evidence in favour or against the conservative therapies for TMD on changes in otologic signs and symptoms. Thus, further studies with a higher level of evidence and more representative samples should be conducted to better understand the relationship of TMD therapy changes on otologic complains.

Influence of age on IgE response in peanut-allergic children and adolescents from the Mediterranean area.

BACKGROUND: Peanut allergens are common triggers of food allergy. Analyses of sensitization patterns, relationships with other allergens, clinical symptoms, and variation with age are needed. We studied sensitization to Ara h 2, Ara h 9, and Pru p 3 in a peanut allergic children/adolescents and the relationship with peach and pollen. METHODS: Peanut allergic patients aged between 1 and 20 years old were classified into two groups: A) allergic to peanut only and B) allergic to peach and peanut. The IgE response was measured to Ara h 2, Ara h 9, and Pru p 3. RESULTS: Of 964 subjects evaluated, 28% were allergic to peanut. From this group, 68% were also sensitized to pollen. Urticaria was the most frequent entity followed by anaphylaxis and OAS. Fifty-eight percent had Ara h 2- and/or Ara h 9-specific IgE. More than half reported symptoms with peanut alone (Group A) and 35% to peanut and peach (Group B). We observed significant differences in sex, age, onset of symptoms, and sensitization to Artemisia between groups. IgE response to Ara h 2 was more frequent in Group A, and Ara h 9 and Pru p 3 in Group B. We observed a decrease in sensitization to Ara h 2 and an increase to Ara h 9 and Pru p 3 with increasing age. CONCLUSION: Peanut allergy is frequent in subjects with allergy to plant foods, with Ara h 2 and Ara h 9 being two important allergens. In younger patients, Ara h 2 predominates over Ara h 9. The reverse was observed in older patients.

Hypersensitivity to Nonsteroidal Anti-inflammatory Drugs in Children and Adolescents: Cross-Intolerance Reactions.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are used worldwide and are responsible for several types of drug hypersensitivity reactions (DHRs) in all age groups. The 2 major groups of DHRs to NSAIDs are those induced by immunological mechanisms (selective reactions) and those where inflammatory mediators are released through activation of the prostaglandin-leukotriene pathway without specific immunological recognition (cross-intolerance). In the present review, we focus on cross-intolerance reactions, which are the most frequent DHRs and are becoming a topic of major interest in children and adolescents. Paracetamol and ibuprofen are the drugs that most frequently cause DHRs in children; other NSAIDs are responsible for reactions in adolescents. In vivo and in vitro tests are of limited diagnostic value, with some exceptions for the less common selective reactions. In cross-intolerance, the clinical history and controlled administration are in many instances the only way to establish a diagnosis and look for alternatives. The clinical history is diagnostic when consistent symptoms occur repeatedly after exposure to NSAIDs with different chemical structures. Cutaneous and respiratory symptoms often co-occur in young children. The natural history of these reactions in children is unknown, and some patients can develop tolerance over time. Atopy remains a major risk factor for cross-intolerant reactions. The increasing interest in hypersensitivity to NSAIDs with improvements in patient phenotyping and the information provided by pharmacogenetics will improve our understanding and management of these reactions in the near future.