Search

We present a first-principles scheme for incorporating many-body interactions into the unified description of the quadratic optical response to light of noncentrosymmetric crystals. The proposed method is based on time-dependent current-density response theory and includes the electron-hole attraction \textit{via} a tensorial long-range exchange-correlation kernel, which we calculate self-consistently using the bootstrap method. By bridging with the Wannier-interpolation of the independent-particle transition matrix elements, the resulting numerical scheme is very general and allows resolving narrow many-body spectral features at low computational cost. We showcase its potential by inspecting the second-harmonic generation in the benchmark zinc-blende semiconductor GaAs, the layered graphitic semiconductor BC$_{2}$N and the Weyl semimetal TaAs. Our results show that excitonic effects can give rise to large and sharply localized one- and two-photon resonances that are absent in the independent-particle approximation. We find overall good agreement with available experimental measurements, capturing the magnitude and peak-structure of the spectrum as well as the angular dependence at fixed photon energy. The implementation of the method in Wannier-based code packages can serve as a basis for performing accurate theoretical predictions of quadratic optical properties in a vast pool of materials., Comment: 15 pages, 6 figures

Background: As the body's protective skin barrier is breached in open fractures, and the potential of contamination is high, these can lead to significant morbidity. Vacuum-assisted closure (VAC) is the application of the negative pressure in open wounds, and it significantly improves wound healing both at the macro and micro levels. Material and Method: A total of 30 patients (23 males and 7 females with a mean age of 27 years) with large open fractures of long bones who received VAC therapy during the early period of treatment were studied. VAC dressing over wound was done following percutaneous pinning or external fixation. In addition, rates of infection, fracture union, duration of application of VAC, and the association of duration of VAC with the development of complications were evaluated. Results: The mean time between the trauma and the first debridement was 8.20 hours (range, 2–23). The mean duration of VAC application was ten days (range, 3–16). Delayed wound closure was performed in nine patients. In the remaining 21 patients, the mean decrease in the wound dimensions between pre and post-VAC application was found to be 43.06% (range, 20–60%). Conclusion: VAC application increases the patient's comfort by reducing the need for dressing changes, improves blood circulation, accelerates the formation of granulation tissue, reduces the rate of infection from the hospital environment, decreases edema, alleviates the need for secondary interventions, and also decreases wound dimensions. Keywords: wound, open fractures, vacuum-assisted closure, wound healing.

Spinel vanadates (AV2O4) are a class of materials where an interesting interplay between spin and orbital degrees of freedom on a frustrated lattice is manifested in the multiple structural and magnetic phase transitions. CoV2O4 is unique among the spinel vanadates as it shows no or very weak cubic to tetragonal structural phase transition but two magnetic (paramagnetic to collinear ferrimagnetic and collinear to noncollinear ferrimagnetic) phase transitions at lower temperatures in its bulk form. In a recent experiment (Thompson et al., Phys. Rev. Mater. 2 (2018) 104411), an epitaxial thin film of CoV2O4 grown on the SrTiO3 (001) substrate, is observed to have an orthorhombic structural phase accompanied by a noncollinear magnetic state where the spin moments of Co and V are reoriented from [001] (seen in the bulk form) to the [110] direction. In this work, we have explored the mechanism behind this complex spin-reorientation and noncollinear magnetic ground state by investigating the electronic structure, magnetic, and structural properties of CoV2O4 in its orthorhombic phase and compared with the corresponding properties of the cubic phase using the first principles density functional theory. Our GGA+U+SO calculations on orthorhombic CoV2O4 reveal that spin moments prefer to lie in the ab-plane with the crystallographic b-direction being the preferred direction in the collinear ferrimagnetic state where it has a larger band gap and orbital moment (of V) as compared to the cases with spin moments aligned parallel to a and c-directions. We further observe competing magnetic exchange interaction values in orthorhombic phase when the spins lie in the ab-plane giving rise to more frustration and hence more canting in the non-collinear magnetic ground stateas compared to the cubic phase, consistent with experiment. With the help of source-free exchange–correlation (XC) functional we were able to capture the non-collinear magnetic ground state and the spin-reorientation in this system. We also discussed the possible orbital ordering in the orthorhombic phase of CoV2O4., MS would like to acknowledge the Ministry of Education, India for the research fellowship and also expresses gratitude for the computing facility (KALAM HPC) at Physics Department IITR, India.

Obstructive sleep apnea occurs in a significant proportion of children and adolescents and requires a sleep study to diagnose the condition. However, there are relatively few sleep laboratories that serve this population. Consequently, this means sleep studies are not done in a timely manner, and many of these patients do not get studies performed when indicated. Building new pediatric-focused sleep laboratories or expanding service in an adult-focused laboratory to children can help overcome this barrier.The decision to build or modify an existing sleep laboratory for children brings many considerations that are different than for adults. The location of the laboratory is partially determined by the need for the presence of a sleep technologist. Whether they are done in the community or a hospital will be affected by the patient's medical complexity. The design of the sleep laboratory can also be influenced by the presence of children. All children, under 18 years of age, will require a parent to sleep in the room with them. Safety will also be impacted. For example, electric outlets need to be protected, furniture should be child safe, and transportation to emergency facilities must be managed. In addition, service to children also raises technical issues. They require different types of leads and smaller equipment and the software must meet required pediatric specifications. The staff must understand pediatric developmental, social, and medical needs. It is also critical that they have a desire to work with children.This article is written to assist the reader in building a sleep laboratory with the pediatric patient in mind.

Using first principles density functional theory, we have studied the interaction mechanism of NO2 and SO2 gas molecules on an MoB2 monolayer, for gas sensing applications. The selectivity for a particular gas by the sensor has been analyzed through electronic structure calculations and adsorption studies. The calculations have been performed by considering the fact that the MoB2 monolayer as a sensing material encounters a change in its electrical properties, when gas molecules with different orientations get adsorbed on the surface. From the density of states study, we find better selectivity for NO2 as compared to SO2, as the latter leaves the electronic structure of the sensing material unaffected. Further, the adsorption curves support the above fact as the larger value of adsorption energy (Ead ∼ −1 eV) for NO2 indicates stronger adsorption. The chemisorptive nature for NO2, in contrast with the relatively weaker physisorption for SO2, additionally supports the fact that NO2 gas has a better perspective for MoB2 sensor application. Charge density plots for each case are in good agreement with the above conclusions. The faster recovery time attributes the MoB2 monolayer better as a sensor material for NO2 interaction.

Background: Avascular necrosis (AVN) or osteonecrosis is the death of bone tissues due to decreased blood flow of femoral head, it is a major orthopaedic disease with many risk factors including the chronic alcohol and tobacco consumption. Aims and objectives: To study the relationship of alcohol and tobacco with AVN of femoral head in adult population. Materials and Methods: This study included 72 patients of AVN of femoral head (ONFH) who attending our hospital between Sept 2018 to Sept 2020. History of alcoholism and tobacco consumption, detailed information of the amount and duration of smoking and alcohol intake was recorded. Results: Majority of the AVN patients were working age groups males (72%) and 28% were females. Out of 72 patient 55% had history of alcohol consumption and 60% were smokers which indicates a positive correlation of cellular toxicity with AVN of femoral head. Conclusion: Present study conclude that the alcohol ingestion and tobacco smoking are the major cause of cellular toxicity and AVN of femoral heads. Keywords: alcohol drinking, femur head necrosis, smoking

Introduction: Adhesive capsulitis is a painful impairment characterized by the restriction of movement of shoulder due to the adhesions across the glenohumeral joint, injection of platelet-rich plasma is effective treatment to reduce the pain and restore the movement of shoulder. Aim: To assess the effectiveness single PRP injection in management of adhesive capsulitis. Material and Methods: This study enrolled 12 patients experiencing the shoulder pain for at least 3 months and attending our medical college hospital. Patients with adhesive capsulitis were given a single injection of PRP (4 ml) and followed up for 12 weeks, VAS scores and Disability Index scores were recorded and compared with the baseline scores. Result: In present study majority of patients were females with mean duration of symptoms was 3 months. Post PRP treatment all the patients have shown significant improvement on pains VAS score, movement VAS score on 2nd, 6th, and 12th weeks follow up. Conclusion: Present studies conclude that the AC is more prevalent among females which can be treated effectively with PRP technique. PRP as is a simple, safe and cost-effective management of AC without any adverse effects. Keywords: Adhesive Capsulitis, Platelet-Rich Plasma, Corticosteroid, Intra-articular

The purpose of this chapter is to provide a framework that will guide the reader through a practical stepwise approach toward a well-rounded initial clinical encounter with pediatric patients presenting with sleep complaints. Aspects of normal human sleep that are useful in the initial encounter are emphasized. The finer points of history-taking skills that may hold the key to successful interventions are discussed. The spectrum of diagnostic possibilities and available assessment tools are illustrated with the help of a concept map in order to provide a 10,000-foot view of the management approach. Within this map, diagnostic categories that overarch the spectrum of sleep disorders are presented alongside pointers to diagnostic tools that may be useful in these scenarios. Common scenarios where investigations are not indicated and only reassurance is required are presented. It is hoped that this chapter will provide the less experienced sleep practitioner with the initial building blocks for constructing what will eventually be their own unique clinical style.

Background Prucalopride drug estimation was reported previously by UV spectroscopy methods and few HPLC methods with retention time 4.73 min as per literature survey. Aim of study A new analytical RP- HPLC method development and validation for bulk and pharmaceutical dosage forms of Prucalopride drug with less retention time than reported methods.Methodology The separation was carried out by using RP-HPLC with the mixture of 0.1 orthophosphoric acid methanol in ratio of 3070 vv as mobile phase. The mobile phase at a flow rate of 1 mLmin was pumped and UV detection was found at 225 nm.Results The selected chromatographic conditions gave retention time at 1.5 min for Prucalopride. Conclusion This developed method was validated for precision accuracy linearity robustness as per International Conference of Harmonization ICH guidelines.

The recent discovery of high-${T}_{c}$ superconductivity in Sr-doped ${\mathrm{NdNiO}}_{2}$ has sparked a renewed interest in investigating nickelates as cuprate counterparts. Parent cuprates $[{\mathrm{Cu}}^{2+}:{d}^{9}]$ are antiferromagnetic charge transfer insulators with the involvement of a single ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ band around the Fermi level and strong $p\text{\ensuremath{-}}d$ hybridization. In contrast, isoelectronic ${\mathrm{NdNiO}}_{2}$ $[{\mathrm{Ni}}^{+}:{d}^{9}]$ is metallic with a ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ band self-doped by Nd-$d$ states. Using first principles calculations, we study the effect of Sr doping in the electronic and magnetic properties of infinite-layer nickelates as well as the nature of holes upon doping. We find that hole doping tends to make the material more cupratelike as it minimizes the self-doping effect, it enhances the $p\text{\ensuremath{-}}d$ hybridization, and it produces low-spin ($S=0$, nonmagnetic) ${\mathrm{Ni}}^{2+}$ dopants.

The discovery of superconductivity in Sr-doped NdNiO$_{2}$ is a crucial breakthrough in the long pursuit for nickel oxide materials with electronic and magnetic properties similar to those of the cuprates. NdNiO$_2$ is the infinite-layer member of a family of square-planar nickelates with general chemical formula R$_{n+1}$Ni$_n$O$_{2n+2}$ (R = La, Pr, Nd, $n= 2, 3, ... \infty$). In this letter, we investigate superconductivity in the trilayer member of this series (R$_4$Ni$_3$O$_8$) using a combination of first-principles and $t-J$ model calculations. R$_4$Ni$_3$O$_8$ compounds resemble cuprates more than RNiO$_2$ materials in that only Ni-$d_{x^{2}-y^{2}}$ bands cross the Fermi level, they exhibit a largely reduced charge transfer energy, and as a consequence superexchange interactions are significantly enhanced. We find that the superconducting instability in doped R$_4$Ni$_3$O$_8$ compounds is considerably stronger with a maximum gap about four times larger than that in Sr$_{0.2}$Nd$_{0.8}$NiO$_2$., 16 pages, 7 figures

In view of the recent experimental predictions of a weak structural transition in CoV

This preliminary study investigated the tolerability and efficacy of a novel mattress technology-the Sound-To-Sleep (STS) system-in the treatment of sleep problems in children with autism.After screening, 45 children, ages 2.5 to 12.9 years, were randomized to order of mattress technology use (On-Off vs. Off-On). Treatment conditions (On vs. Off) lasted two weeks with immediate crossover. Tolerability, including study discontinuation and parent-report of mattress tolerance and ease of use, was tracked throughout the study. Efficacy assessments were obtained at baseline, prior to crossover, and end of study and included measures of autism traits, other psychopathology symptoms, sensory abnormalities, communication difficulties, quality of life, sleep diary parameters, and single-blinded actigraphy-derived sleep parameters. Statistical analyses evaluated differences in tolerability and efficacy when the STS system was on versus off.STS system use was well tolerated (n = 2, 4.4% dropout) and resulted in parent-reported sleep quality improvements (STS off mean = 4.3, 95% CI = 4.05-4.54 vs. on mean = 4.9, 95%CI = 4.67-5.14). The technology was described by parents as very easy to use and child tolerance was rated as good. Parent-diary outcomes indicated improvements in falling asleep and reduced daytime challenging behavior. Actigraphy-derived sleep parameters indicated improved sleep duration and sleep efficiency. Improvements in child and family quality of life were identified on parent questionnaires.A future large sample phase 2 trial of the STS system is warranted and would benefit from extended study duration, an objective primary efficacy outcome, and careful attention to methodological issues that promote compliance with the intervention and study procedures.

In view of the recent experimental predictions of a weak structural transition in CoV$_{2}$O$_{4}$ we explore the possible orbital order states in its low temperature tetragonal phases from first principles density functional theory calculations. We observe that the tetragonal phase with I4$_1/amd$ symmetry is associated with an orbital order involving complex orbitals with a reasonably large orbital moment at Vanadium sites while in the phase with I4$_1/a$ symmetry, the real orbitals with quenched orbital moment constitute the orbital order. Further, to study the competition between orbital order and electron itinerancy we considered Mn$_{0.5}$Co$_{0.5}$V$_{2}$O$_{4}$ as one of the parent compounds, CoV$_{2}$O$_{4}$, lies near itinerant limit while the other, MnV$_{2}$O$_{4}$, lies deep inside the orbitally ordered insulating regime. Orbital order and electron transport have been investigated using first principles density functional theory and Boltzmann transport theory in CoV$_{2}$O$_{4}$, MnV$_{2}$O$_{4}$ and Mn$_{0.5}$Co$_{0.5}$V$_{2}$O$_{4}$. Our results show that as we go from MnV$_{2}$O$_{4}$ to CoV$_{2}$O$_{4}$ there is enhancement in the electron's itinerancy while the nature of orbital order remains unchanged., 8 pages, 6 figures

Capturing the non-collinear magnetic ground state of the spinel vanadates AV$_2$O$_4$ (A= Mn, Fe and Co) remains an outstanding challenge for state-of-the-art ab-initio methods. We demonstrate that both the non-collinear spin texture, as well as the magnitude of local moments, are captured by a single value of the on-site Hubbard $U$ of 2.7~eV in conjunction with the local spin density approximation (LSDA+$U$), provided the source term (i.e., magnetic monopole term) is removed from the exchange-correlation magnetic field ${\bf B}_{XC}$. We further demonstrate that the magnetic monopole structure in ${\bf B}_{XC}$ is highly sensitive to the value of $U$, to the extent that the interplay between on-site localization and local moment magnitude is qualitatively different depending on whether the source term is removed or not. This suggests that in treating strongly correlated magnetic materials within the LSDA+$U$ formalism, subtraction of the unphysical magnetic monopole term from the exchange-correlation magnetic field is essential to correctly treat the magnetic ground state., Comment: 4 pages, 3 figures

The association between childhood obstructive sleep apnea (OSA) and sleep enuresis has been known for some time. This case discusses current understanding of the pathophysiologic relationship between the two. The authors also discuss the current diagnostic criteria and standardized terminology of enuresis as developed by the International Children’s Continence Society and the American Academy of Sleep Medicine. Components of a sleep history and physical examination that are key to establishing the complex relationships between enuresis and OSA are reviewed. Hypotheses for the higher prevalence of sleep enuresis in patients with OSA are summarized. Although the treatment of OSA often results in reversal of enuresis, and the mechanistic pathways appear plausible, the strength of evidence in the literature that OSA causes enuresis in children is not very strong, and further research is warranted.

A new multisensor (i.e. resistive and magnetic) $CrI_{3}$-$WTe_{2}$ heterostructure (HS) to detect the toxic gases $BrF_3$ and $COCl_2$ (Phosgene) has been theoretically studied in our present investigation. The HS has demonstrated sensitivity towards both the gases by varying its electronic and magnetic properties when gas molecule interacts with the HS. Fast recovery time ($< 0.14 fs$) under UV radiation has been observed. We have considered two configurations of $BrF_3$ adsorbed HS; 1) when F ion interacts with HS (C1) and 2) when Br ion interacts with HS (C2). In C1 case the adsorption energy $E_{ad}$ is observed to be -0.66 eV while in C2 it is -0.95 eV. On the other hand in case of $COCl_2$ $E_{ad}$ is found to be -0.42 eV. Magnetic moments of atoms are also found to vary upon gas adsorption indicates the suitability of the HS as a magnetic gas sensor. Our observations suggests the suitability of $CrI_{3}$-$WTe_{2}$ HS to respond detection of the toxic gases like $BrF_3$ and $COCl_2$., 7 pages, 4 figures

Using first principles density functional theory, we have studied the interaction mechanism of NO2 and SO2 gas molecules on an MoB2 monolayer, for gas sensing applications. The selectivity for a particular gas by the sensor has been analyzed through electronic structure calculations and adsorption studies. The calculations have been performed by considering the fact that the MoB2 monolayer as a sensing material encounters a change in its electrical properties, when gas molecules with different orientations get adsorbed on the surface. From the density of states study, we find better selectivity for NO2 as compared to SO2, as the latter leaves the electronic structure of the sensing material unaffected. Further, the adsorption curves support the above fact as the larger value of adsorption energy (Ead ∼ -1 eV) for NO2 indicates stronger adsorption. The chemisorptive nature for NO2, in contrast with the relatively weaker physisorption for SO2, additionally supports the fact that NO2 gas has a better perspective for MoB2 sensor application. Charge density plots for each case are in good agreement with the above conclusions. The faster recovery time attributes the MoB2 monolayer better as a sensor material for NO2 interaction.

Objective There is a lack of consensus and a paucity of data regarding how to best treat pediatric patients with mild obstructive sleep apnea. The objective of our study was to compare outcomes following adenotonsillectomy vs. observation in children with mild obstructive sleep apnea based on polysomnography results. Methods A retrospective chart review was performed on children ages 9 months to 9 years with 2 or more polysomnograms completed at a tertiary care academic center. Children diagnosed with mild obstructive sleep apnea (obstructive apnea–hypopnea index 1–5) on polysomnography performed from 1999 to 2013 were included. Patients underwent adenotonsillectomy or watchful waiting for obstructive sleep apnea. The primary outcome was the change in apnea–hypopnea index. Results There were 62 patients who met inclusion criteria for the study; 19 of the 62 patients were obese, while 15 had a craniofacial syndrome or hypotonia. Eighteen patients underwent adenotonsillectomy for mild obstructive sleep apnea while 44 were observed. The mean apnea–hypopnea index of patients after adenotonsillectomy improved from 3.50 (95% Confidence Interval [CI] 2.97–4.03) to 2.69 (95% CI 1.48–3.90), while the mean apnea–hypopnea index of the observation group worsened from 3.09 (95% CI 2.76–3.42) to 5.18 (95% CI 2.46–7.90). Between-group analysis showed significant improvement in the surgery group ( p = 0.03), with a persistent improvement on multivariate analysis adjusting for baseline apnea–hypopnea index ( p = 0.05). This difference was seen mostly in non-obese, non-syndromic children ( p = 0.04). There was no significant difference between groups amongst obese ( p = 0.25) and syndromic ( p = 0.36) patients. Conclusions Adenotonsillectomy leads to a significant improvement in apnea–hypopnea index on follow-up polysomnography over an observational approach, especially in non-obese, non-syndromic children. A prospective, randomized trial is necessary to help determine appropriate treatment strategies for pediatric mild obstructive sleep apnea.

Recent experimental measurements on the layered triangular-lattice antiferromagnet ${\mathrm{EuCd}}_{2}{\mathrm{As}}_{2}$ have revealed an interesting interplay among magnetism, charge transport, and optical properties. To explore the nature of the interaction among these degrees of freedom, the electronic structure, magnetic properties, electrical transport, and optical properties of ${\mathrm{EuCd}}_{2}{\mathrm{As}}_{2}$ are investigated using density functional theory and Boltzmann transport theory under various approximations such as the generalized gradient approximation (GGA), GGA+$U$, and GGA+$U$+spin orbit (SO). A semimetallic electronic structure with compensating electron and hole pockets is observed. Among the various magnetic states studied, A-type antiferromagnetic (A-AFM) and ferromagnetic (FM) states emerge as having competing total energies even though A-AFM is found to be energetically favored. Further, our GGA+$U$+SO calculations reveal the presence of a magnetic anisotropy which drives the spin moments to align along the crystallographic $b$ direction. We observe from our transport calculations that in the case of A-AFM, the anisotropy between out-of-plane and in-plane resistivities $({\ensuremath{\rho}}_{zz}/{\ensuremath{\rho}}_{xx})$ is much higher than that in the FM case, and it increases as temperature goes down, exactly what has been observed experimentally for this system. The huge difference between the resistivities of A-AFM and FM states at lower temperatures is indicative of the presence of negative magnetoresistance in the system as seen in the experimental measurements. In-plane optical reflectivity reveals that intraband contributions play a major role in reproducing the experimental features in the low-frequency regime.

Two dimensional (2D) layered transition metal dichalcogenides (TMDs) have recently become the foremost candidate for future electronic device applications overcoming graphene as latter has no bandgap which limits some of the applications. WTe2 is one such TMD whose magnetoresistance (MR) continue to increase with magnetic field without any indication of saturation. Inspired by this, we have theoretically investigated the material using first principle density functional theory (DFT) approach to study the effect of magnetic field on electronic structure of the compound. The magnetic field is seen to enhance the hole pockets’ size along Γ-Z direction, which brings in significant change in the Fermi surface topology.

Inspired by the recent experiments, we have theoretically investigated the compound Mn1-xCoxV2O4 using first-principles density functional theory for x = 0.0, 0.25, 0.5, 0.75. On increasing Co doping on Mn site, chemical pressure on V-V bonds increases which make the system more itinerant as indicated by decrease in the calculated RV-V values with increasing x. The calculated band gap is also seen to decrease with increasing x. This Co-doping induced itinerancy facilitates superexchange interaction among Co and V ions leading to an increase in the magnetic transition temperature.

Among disorders of circadian rhythm, Delayed Sleep-Wake Phase Syndrome is common in adolescents and young adults, a population that has a natural endogenous shift towards later bedtimes. In the current edition of the International Classification of Sleep Disorders (ICSD-3) it is now listed as Delayed Sleep-Wake Phase Disorder (DSWPD). Genetic, environmental, social, and behavioral factors play important roles in the development and perpetuation of this disorder. Delay in the ability to fall asleep at conventional times in affected individuals gives the appearance of sleep-onset insomnia. However, the affected individuals sleep for a normal amount of time if they do not have a social obligation to wake up at a conventional time. Usually, no problems with sleep maintenance are described. If sleep is curtailed due to social obligations, daytime consequences of DSWPD may occur, including sleep inertia, excessive daytime sleepiness, mood changes, cognitive deficits, or decline in academic performance. These may trigger excessive caffeine intake or substance use. A comprehensive sleep history with sleep logs and actigraphy (if available) are essential for an appropriate diagnosis of DSWPD. A number of treatment options exist including phase shifting (advancing or delaying), melatonin, bright light therapy, and improvement in sleep hygiene. Comorbid sleep disorders must be carefully screened for and excluded. Successful outcomes hinge very much on school and family cooperation as well as the patient’s motivation for change.

Venous malformations and lymphatic malformations of the head and neck region are uncommon causes for obstructive sleep apnea in the pediatric population. The need for treatment for these malformations depends on the location and size of lesion and associated complications such as ulceration, bleeding, or chronic airway obstruction leading to obstructive sleep apnea. Treatment options for obstructive sleep apnea include conservative approach with continuous positive airway pressure therapy, surgical excision, and sclerotherapy. Management of children with large venous or lymphatic malformations that develop severe obstructive sleep apnea often requires multidisciplinary care involving otolaryngology, sleep medicine, and interventional radiology. We report 2 pediatric cases, one with congenital lymphatic malformation and another with venous malformation causing polysomnographically confirmed severe sleep apnea and discuss their management.

A 15 year-old girl who was previously well presented with severe recurrent episodic hypersomnia associated with abnormal behavior and hyperphagia after recovery from a mild upper respiratory tract infection (URTI). Physical examination was unremarkable with normal blood tests, brain imaging and electroencephalogram (EEG). A multiple sleep latency test (MSLT) during a typical episode showed moderate hypersomnolence in contrast to a normal MSLT performed an the interval between episodes. Clinical features were consistent with Kleine-Levin syndrome (KLS). She was started on carbamazepine treatment after failing a trial of methylphenidate and is currently being followed up for her symptoms.

5p- is a well-defined syndrome, but phenotypic correlations of 5q are poorly described in the literature. We present a case of a female child with interstitial deletion in the 5q13.1q15 region. Comparison of the clinical features of this patient with others reported in the literature suggests an emerging clinical syndrome defined by short stature, failure to thrive, mental retardation, slanting palpebral fissures, malformed ears, short neck and depressed nasal bridge. Based on our endocrine testing, we hypothesize that the short stature could be, in part, due to growth hormone deficiency. The recent assignment of growth hormone receptor gene to the short arm of chromosome 5 and the presence of several genes for growth factors and growth factor receptors on 5q raise interesting possibilities for the explanation of short stature in such cases.

Understand the role of the sleep laboratory for diagnosis and management of a spectrum of pediatric sleep disorders.Learn about the special equipment and techniques important in studying pediatric patients.Understand recent advances and newer techniques in monitoring pediatric sleep.

Caffeine, a commonly consumed psychoactive substance, can have significant effects on sleep. Caffeine intake among children is increasing, mainly in the form of sodas. However, adolescent caffeine consumers may lack knowledge about the caffeine content in common beverages. If true, this very fact may hamper the assessment of the effects of caffeine consumption on sleep in children if such assessments are a priori dependent on responders being able to reliably distinguish between caffeinated and noncaffeinated beverages. This preliminary study investigated adolescents' caffeine knowledge and intake at a Cleveland-area public middle school.Seventh- and eighth-grade students were surveyed using: (1) the Caffeine Literacy and Sleep Study (CLASS), a 15-question pilot instrument designed to assess caffeine knowledge and intake by type, quantity and timing, as well as sleep habits; and (2) the Cleveland Adolescent Sleepiness Questionnaire (CASQ), a validated survey measuring excessive daytime sleepiness in adolescents. These questionnaires were distributed and collected during a specified class period.Of the 635 seventh- and eighth-grade students who attended school on the day of the study, 555 (87%) participated. Lack of knowledge about caffeine content of particular drinks was noted in seventh and eighth graders of both sexes with nearly 29% unaware that their favorite drinks contain caffeine and more than 50% unable to correctly identify the drinks with the most caffeine. A low percentage of students correctly identified light-colored sodas lacking caffeine: 7-Up (24.1%), Sierra Mist (38.9%), ginger ale (39.8%), Sprite (39.8%), and Fresca (53.7%). The percentages of students correctly identifying caffeinated light-colored beverages were: Arizona Green Tea (43.5%), Mello Yellow (50.9%), and AW cream soda (67.6%). However, Mountain Dew was correctly identified by most (93.5%) as caffeinated.Students were not consistently able to identify caffeine content or lack thereof in some common beverages. The results of this pilot study show that caffeine literacy in adolescents warrants further investigation and educational intervention.

While neck circumference (NC) is a useful predictor of obstructive sleep apnea (OSA) in adults, childhood OSA is difficult to predict clinically. We utilized the neck circumference-height ratio (NHR) to normalize NC in growing children. Our study aimed to determine if (1) NC is a reproducible clinical measurement; (2) NHR predicts OSA in children; (3) this metric translates to adults.For this retrospective study, paired NC measurements (from clinic and sleep laboratory) in 100 consecutive adult subjects were used to confirm inter-observer reproducibility. Polysomnographic (PSG) and anthropometric data from children aged 5-18 years presenting consecutively between July 2007 and February 2012 was obtained. Children with genetic syndromes, severe neurological disorders, craniofacial abnormalities, tracheostomy, past adenotonsillectomy, in-hospital PSG or sleep efficiency80% were excluded. Data were analyzed using χ(2) test and logistic and linear regression models. These analyses were also applied to 99 adult patients with similar exclusion criteria.Adult NC measurement had inter-observer correlation of 0.85 (N = 100). Among children, after correcting for BMI-Z scores, NHR conferred additional predictive value, in both logistic regression and linear models, for both apnea-hypopnea index (AHI)2 and5 (N = 507). In children, for NHR0.25, the odds ratio of AHI2 was 3.47. In adults, for NHR0.25, the odds ratio of AHI5 was 18.NHR can be included as a simple screening tool for OSA in children and adults, which along with other predictors, may improve the ability of clinicians to triage children and adults at risk for OSA for further evaluation with PSG.

Advanced radiological imaging has largely replaced exploratory operations and has become an essential diagnostic tool clinicians routinely rely on. However, physicians are faced with a lot of radiological findings without histological proof, and assuming a more serious diagnosis may lead to unnecessary investigations and emotional stress for patients. We report an unusual presentation of chronic appendicitis with a synchronous peritoneal nodule on CT in a 76-year-old woman who presented with poor appetite, weight loss and a mass in the right iliac fossa. The coincidental finding of the nodule in addition to the suspicious appearance of the appendix raised concerns for primary appendiceal cancer with peritoneal metastasis. The case illustrates the patient's management and reflects on the learnt lessons with regard to careful use of invasive radiology-guided biopsies and interval imaging, as these could sometimes delay the diagnosis and management of a readily treatable disease.

Children with Down syndrome (DS) commonly have obstructive sleep apnea syndrome (OSAS) and may assume a unique sleeping position not systematically described previously. We describe this sleep position in DS and explore its relationship with OSAS in comparison to control children (CC).Overnight video-polysomnograms (PSG) of consecutive children with DS (age 2-18 y), referred to our center between April 2008 and October 2009, were retrospectively analyzed by a single scorer (ES). CC group comprised age and gender matched, non-syndromic, neurologically intact children referred to us for suspected OSAS over the same period.Each group had 17 subjects matched for age (median [IQR]; 6 [4-8]) and gender (65% female). DS group had higher BMI (median [IQR]; 18.8 [17.4-21.0]) than CC (17 [14.7 -18.8]; p = 0.03). There were however no significant differences (median [IQR]) between DS and CC with respect to sleep time in minutes (460 [425-499] vs 424[410-483]), sleep efficiency (%) (90.9 [87.4-92.4] vs 88.6 [79.9-93.1]), REM time (%) (17.1 [14.2-22.1] vs 19.2 [14.9-22.1]), supine time (%) (40.7 [24.8-56.0] vs 15.8 [0.40-44.5], p 0.06), mean oxygen saturation (%) (95 [94-96] vs 96 [95-97]), oxygen saturation nadir (89 [86-91] vs 89[94-92]), or total apnea-hypopnea index (4.3 [3-7.8] vs 5.1[1.9-9.6]). Despite these similarities between the groups, 9 (53%) DS children slept seated bent forward with head resting on bed for at least part of the total sleep time (%) (7.8 ± 10.9, range 0.8-35.7).This was absent in the CC group (p = 0.06).Some DS children assume a peculiar body position, sitting cross-legged flopped-forward with head resting on bed while asleep. This is absent in age- and gender-matched controls showing otherwise similar PSG characteristics. The reason for this posture is unclear from this study. However, this novel report of a unique sleeping position would provide us with a basis to conduct a prospective study involving a larger population to ascertain the contribution of this position for OSAS protection or to determine if it may be forme fruste parasomnia.

This study was designed to determine the need for water supplementation to maintain water homoeostasis in exclusively breastfed infants during summer in a tropical country. A prestudy questionnaire revealed that 97% of 34 nurses and 63% of 70 doctors advocated such supplementation. 45 healthy, male, exclusively breastfed babies, aged 1-4 months, were recruited from a well-baby clinic. 9 who had never received supplemental water plus a random selection of 14 others were allocated to group I (breastmilk only); the remaining 22 infants were allocated to group II (breastmilk plus supplemental fluid according to the mother's usual practice). The babies were studied at the hospital for 8 h; breastmilk intake was measured by weighing the infant before and after each feed, water intake by calibrated bottles, and urine output by accurate collection and measurement. The maximum room temperatures were 34-41 degrees C and relative humidities 9-60% (below 50% in all but 3 infants). In group II the mean water intake was 11% (95% confidence interval 7-16%) of the total fluid intake. Both breastmilk intake (274 vs 210 ml) and total fluid intake (274 vs 233 ml) were higher in group I than in group II (p = 0.003, p = 0.073, respectively), after adjustment for age, weight, length, room temperature, and humidity. However, there were no significant differences between the groups in urine output, urine or serum osmolality, weight change, or rectal temperature whether or not the factors adjusted for included total fluid intake. Thus, exclusively breastfed infants do not need supplemental water to maintain water homoeostasis; a reduced breastmilk intake is a potential disadvantage of this practice.