Difficult management of an extremely rare case of giant pigmented epithelioid melanocytoma

Pigmented epithelioid melanocytoma (PEM), a heavily pigmented and highly uncommon melanocytic lesion, is extremely rare. It comes under several forms and names. We report the case of a three-year-old boy born with an isolated right lumbopelvic and femoral giant PEM. The boy was unable to walk due to the size and the shape of the lesion. He underwent two stages of intra lesional resections, one in Benin and the second in Switzerland. The first surgery was followed by hypothetic hypovolemic and anaphylactic shocks, and the second surgery by a continuous lymphatic leakage from the wounds for months. The strategic management approach, the surgery and follow-up of this case of giant PEM presented a real challenge. (C) 2017 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND licens

Band gap engineering in AA-stacked bilayer graphene

We demonstrate that AA-stacked bilayer graphene (AA-BLG) encapsulated by dielectric materials can possess an energy gap due to the induced mass term. Using the four-band continuum model, we evaluate transmission and reflection probabilities along with the respective conductance. Considering interlayer mass-term difference opens a gap in the energy spectrum and also couples the two Dirac cones. This cone coupling induces an inter-cone transport that is asymmetric with respect to the normal incidence in the presence of asymmetric mass-term. The energy spectrum of the gapped AA-BLG exhibits electron-hole asymmetry that is reflected in the associated intra- and inter-cone channels. We also find that even though Klein tunneling exists in gated and biased AA-BLG, it is precluded by the interlayer mass-term difference and instead Febry-P\'erot resonances appear.Comment: 11 pages, 9 figure

Smell Dysfunction in Patients with Primary Sjögren’s Syndrome: Impact on Quality of Life

Objectives: Patients with primary Sjögren’s syndrome (pSS) often report smell and taste disturbances. However, the correlation between smell impairment and mucosal dryness is not well understood. The objectives of this study were to investigate the following: (1) the prevalence of smell hypofunction in patients with SS; (2) the impact of smell hypofunction on their quality of life (QoL); (3) whether the patients’ smell is correlated with xerostomia; and (4) whether the patients’ smell is affected by taste hypofunction, disease duration, age, smoking or self-reported neuropathy. Methodology: An ethically approved cross-sectional study was conducted on 65 female patients with SS and 62 sex-matched healthy controls. Their smell was assessed using the University of Pennsylvania Smell Identification Test. Their taste acuity was assessed using the Taste Strips Test. A visual analogue scale was used for the self-assessment of smell and taste functions. Xerostomia was assessed by the salivary flow rate, clinical oral dryness score and the Xerostomia Inventory. The patients’ QoL and mental health well-being were assessed using validated questionnaires. Results: In the SS group, the patients’ smell function was impaired in 27/65 patients compared with the controls (15/62, p < 0.05), and it did not correlate with the severity of xerostomia, taste acuity (r = 0.05, p = 0.6) or self-reported nasal dryness (r = −0.02, p = 0.7). In the patients’ group, smell hypofunction was not correlated with disease duration (β = 0.1, 95% CI = −0.07–0.1) or smoking (β = −0.02, 95% CI = −8–7). Age was not correlated with the smell function in the patients’ group (β = −0.1, p = 0.5) but was correlated significantly with smell in the healthy participants’ group (β = −0.3, p = 0.02). Neuropathy affected 81.2% of the patients’ group. Their QoL and mental health well-being were not affected by smell hypofunction. Conclusion: Smell hypofunction appears to be a clinical manifestation in patients with SS, but it does not seem to be associated with the severity of mucosal dryness or with taste disturbance

THE EFFECT OF PRIMARY SJӦGREN’S SYNDROME ON THE SENSES OF SMELL, TASTE AND SEXUALITY IN FEMALE PATIENTS IN THE UK: IMPACT ON QUALITY OF LIFE

It is well established that mucosal dryness is the most common symptom in primary Sjögren’s Syndrome (pSS) patients, affecting the nasal, oral and genital mucosa. A systematic review was conducted and a study with the following aims was established: 1) To assess the functions of the smell, taste and sexuality in patients with pSS. 2) To determine whether the mucosal dryness has an impact on the functions of the smell, taste and sexuality in pSS patients. 3) To investigate the impact of the impairment of the functions of smell, taste and sexuality on the quality of life (QoL) and mental health well-being in women with pSS. Methodology: Sixty-five pSS patients and 62 sex-matched healthy volunteers were recruited for this study. The smell function was assessed by the University of Pennsylvania Smell Identification Test (UPSIT). The taste function was comprehensively evaluated by assessing the gustatory function using the Taste Strips Test (TST), and the neurosensory threshold by an electrogustometer (EGM). The sexual function was assessed by the Female Sexual Function Index (FSFI). The oral dryness was assessed by means of stimulated and unstimulated salivary flow rate (SFR), clinical assessment of oral dryness scale (CODS) and Xerostomia Inventory (XI). The World Health Organisation Quality of Life-BRÉF (WHOQoL- BRÉF) and Oral Health Impact Profile-14 (OHIP-14) were used for the general and oral health related QoL respectively. The Hospital Anxiety and Depression Scale (HADS) was used to assess the mental health status. Results: Data analysis showed that the smell dysfunction was twice as prevalent in the patients group (41.5%, n=27/65) compared with healthy volunteers (24.1%, n=15/62). This difference was even more pronounced when assessing the gustatory function impairment, which was six times more prevalent in pSS patients (54%, n=34/63) than in healthy participants (8.3%, n=5/60). The neurosensory threshold of taste was three times higher in the patients’ group (31.7%, n=20/64) compared with the healthy volunteers (9.8%, n=6/61), and was associated with gustatory deterioration in pSS group (β=-0.4, 95% CI=-0.2 – 0), indicating possible neurological impairment in this group. As expected, the salivary flow rate and the clinical oral dryness score were significantly lower in the patient group compared with healthy volunteers. No evidence was found to support that the oral dryness was associated with deterioration of smell, taste or sexual functions in pSS patients. The number of sexually active pSS patients (n=28) was half of that in the healthy volunteers group (n=42), and the FSFI showed that the sexual function was significantly impaired in pSS patients (p=<0.05). The self-administered questionnaires showed that the life quality was significantly compromised in patients, who were more anxious (58.5%, n=38/65) and four times more depressed (32.3%, n=21/65) compared with healthy volunteers (Anxiety=21%, n=13/61; depression=8.2%, n=5/61). However, neither smell nor taste dysfunction were contributory factors to the reduced QoL, but the sexual dysfunction was the main factor contributed to the compromised general QoL in pSS patients. Conclusion: The smell, taste and sexual impairment are manifestations seen in pSS, but only the sexual dysfunction appear to have a diminishing effect on the QoL and mental health well-being of patients. The taste deterioration in pSS does not seem to be associated with mucosal dryness but maybe precipitated by a Sjӧgren’s syndrome-associated neuropathy

Topological Flat Bands in Graphene Super-moir\'e Lattices

Moir\'e-pattern based potential engineering has become an important way to explore exotic physics in a variety of two-dimensional condensed matter systems. While these potentials have induced correlated phenomena in almost all commonly studied 2D materials, monolayer graphene has remained an exception. We demonstrate theoretically that a single layer of graphene, when placed between two bulk boron nitride crystal substrates with the appropriate twist angles can support a robust topological ultra-flat band emerging from the second hole band. This is one of the simplest platforms to design and exploit topological flat bands

Infected epidermal cyst of the clitoris in an infant

Clitoral enlargement in the pediatric population is a rare condition, usually related to problems of sexual differentiation, but malignant and benign clitoral lesions have also been described. We report the case of a newborn infant, investigated at birth for an intersex disorder because of clitoromegaly. Hormonal screening was normal and ultrasound (US) did not show a pelvic or abdominal mass. Three weeks later, the lesion was larger, tense and erythematous. An abscess was suspected. A drainage was then performed, and the bacteriological culture revealed the presence of Staphylococci aurei. A magnetic resonance imaging (MRI) performed to exclude a tumor of the soft tissue was normal. A diagnosis of infected epidermal cyst was confirmed by the pathology. Two months later, the external genital aspect was normal and the child asymptomatic

Wild-type and mutant SOD1 share an aberrant conformation and a common pathogenic pathway in ALS.

Many mutations confer one or more toxic function(s) on copper/zinc superoxide dismutase 1 (SOD1) that impair motor neuron viability and cause familial amyotrophic lateral sclerosis (FALS). Using a conformation-specific antibody that detects misfolded SOD1 (C4F6), we found that oxidized wild-type SOD1 and mutant SOD1 share a conformational epitope that is not present in normal wild-type SOD1. In a subset of human sporadic ALS (SALS) cases, motor neurons in the lumbosacral spinal cord were markedly C4F6 immunoreactive, indicating that an aberrant wild-type SOD1 species was present. Recombinant, oxidized wild-type SOD1 and wild-type SOD1 immunopurified from SALS tissues inhibited kinesin-based fast axonal transport in a manner similar to that of FALS-linked mutant SOD1. Our findings suggest that wild-type SOD1 can be pathogenic in SALS and identify an SOD1-dependent pathogenic mechanism common to FALS and SALS

Carrier transport theory for twisted bilayer graphene in the metallic regime

The mechanisms responsible for the strongly correlated insulating and superconducting phases in twisted bilayer graphene are still debated. The authors provide a theory for phonon-dominated transport that explains several experimental observations, and contrast it with the Planckian dissipation mechanism. Understanding the normal-metal state transport in twisted bilayer graphene near magic angle is of fundamental importance as it provides insights into the mechanisms responsible for the observed strongly correlated insulating and superconducting phases. Here we provide a rigorous theory for phonon-dominated transport in twisted bilayer graphene describing its unusual signatures in the resistivity (including the variation with electron density, temperature, and twist angle) showing good quantitative agreement with recent experiments. We contrast this with the alternative Planckian dissipation mechanism that we show is incompatible with available experimental data. An accurate treatment of the electron-phonon scattering requires us to go well beyond the usual treatment, including both intraband and interband processes, considering the finite-temperature dynamical screening of the electron-phonon matrix element, and going beyond the linear Dirac dispersion. In addition to explaining the observations in currently available experimental data, we make concrete predictions that can be tested in ongoing experiments

Analytical Model for Atomic Relaxation in Twisted Moir\'e Materials

By virtue of being atomically thin, the electronic properties of heterostructures built from two-dimensional materials are strongly influenced by atomic relaxation. The atomic layers behave as flexible membranes rather than rigid crystals. Here we develop an analytical theory of lattice relaxation in twisted moir\'e materials. We obtain analytical results for the lattice displacements and corresponding pseudo gauge fields, as a function of twist angle. We benchmark our results for twisted bilayer graphene and twisted WSe$_2$ bilayers using large-scale molecular dynamics simulations. Our theory is valid in graphene bilayers for twist angles $\theta \gtrsim 1^\circ$, and in twisted transition metal dichalcogenides for $\theta \gtrsim 4^\circ$. We also investigate how relaxation alters the electronic structure in twisted bilayer graphene, providing a simple extension to the continuum model to account for lattice relaxation