Strain-induced dark exciton generation in rippled monolayer MoS2.

Recently, it has been revealed that dark excitons play a significant role in optically controlled information processing due to their much longer radiative lifetimes than those of bright ones. For the realizable implementation of the features, it is important to understand and manipulate conditions in which dark excitons could exist. We adopt strain-engineered rippling as a new parameter for the modification of the electronic structure of monolayer MoS2 and demonstrate the efficient conversion of bright to dark excitons via a first-principles study. For rippled monolayer MoS2 above a strain of ∼6.8%, we show that the spin order of the conduction band is reversed and the spin forbidden dark exciton then goes below the bright one.

Dual Resonant Sum Frequency Generations from Two-Dimensional Materials.

We propose dual resonant optical sum frequency generation (SFG), where the two most singular resonances could be selected, and report for the monolayer (1L-) WSe2 when one (ω1) of two excitation pulses is resonant to A exciton and their sum frequency (ω1 + ω2) to D exciton. The dual resonant SFG confirms that, under an irradiation of ω1 and ω2 pulses with the same fluence of ∼1.4 × 1010 W/m2, its signal intensity could be enhanced about 20 times higher than the resonant SHG (i.e., 2ω1 to the D excitonic absorption). Further, the dual resonant SFG intensity of 1L-WSe2 is found to be 1 order of magnitude higher than the single resonant SFG intensity of 1L-WS2 under the same condition of two-pulse irradiation. Finally, observations of the dual resonant SFG are thoroughly examined using real-time time-dependent density functional theory (rt-TDDFT), and the relevant nonlinear optical characteristics are scrutinized using the Greenwood-Kubo formalism.

The learning curve for endoscopic tympanoplasties: a single-institution experience, in Birmingham, UK.

OBJECTIVE: This study aimed to assess whether increasing operative experience results in better surgical outcomes in endoscopic middle-ear surgery. METHODS: A retrospective single-institution cohort study was performed. Patients underwent endoscopic tympanoplasty between May 2013 and April 2019 performed by the senior surgeon or a trainee surgeon under direct supervision from the senior surgeon. Following data collection, statistical analysis compared success rates between early (learning curve) surgical procedures and later (experienced) tympanoplasties. RESULTS: In total, 157 patients (86 male, 71 female), with a mean age of 41.6 years, were included. The patients were followed up for an average of 43.2 weeks. The overall primary closure rate was 90.0 per cent. CONCLUSION: This study demonstrates an early learning curve for endoscopic ear surgery that improves with surgical experience. Adoption of the endoscopic technique did not impair the success rates of tympanoplasty.

A rare differential for sinusitis and visual loss.

Erdheim-Chester disease is a rare infiltrative histiocytic disorder with around 800 cases being reported worldwide. Patients most commonly present with skeletal pain, but the condition has been shown to affect multiple other organs. We describe a rare presentation in which the disease infiltrated the sinuses and affected an ex-RAF pilot's vision. After extensive investigation of the elusive diagnosis, repeating of a molecular test using polymerase chain reaction analysis allowed for identification of a mutation (BRAF V600) ultimately leading to the diagnosis of Erdheim-Chester disease.

The incidence and survival of melanoma and nonmelanoma skin cancer in patients with vitiligo: a nationwide population-based matched cohort study in Korea.

BACKGROUND: While studies report a lower incidence of skin cancer in white patients with vitiligo compared with controls, the skin cancer incidence in Asian patients with vitiligo is unknown. OBJECTIVES: To quantify the incidence of melanoma and nonmelanoma skin cancer (NMSC) in Korean patients with vitiligo and compare it with matched nonvitiligo controls. METHODS: A retrospective matched cohort study was performed with 131 245 incident vitiligo cases and 2 624 900 age- and sex-matched (1 : 20) controls at index date, who were selected from the Korean National Health Insurance database between January 2005 and December 2017. Stratified Cox proportional hazards regression (stratified by sex, birth year and index year) was used to calculate the hazard ratio (HR) of skin cancer in patients with vitiligo. RESULTS: Patients with vitiligo were followed up for a mean duration of 6·34 years compared with a follow-up period of 6·27 years for matched controls. Ultraviolet (UV) treatment-adjusted HR for melanoma in patients with vitiligo was 3·32 [95% confidence interval (CI) 2·29-4·81] and 1·29 (95% CI 1·06-1·56) for NMSC. The HRs for melanoma and NMSC in the vitiligo population without a history of UV treatment were 3·37 (95% CI 2·32-4·90) and 1·35 (95% CI 1·11-1·64), respectively. CONCLUSIONS: In contrast to white patients with vitiligo, the risk of skin cancer was increased in the Korean vitiligo population. However, it is noteworthy that the skin cancer incidence in Korean patients with vitiligo was lower than that of their white counterparts. Owing to possible ethnic differences in the susceptibility to skin cancer, skin cancer surveillance in the vitiligo population may be adjusted for race. What's already known about this topic? Prior studies have reported a lower incidence of melanoma and nonmelanoma skin cancer (NMSC) in white patients with vitiligo compared with nonvitiligo controls. The skin cancer incidence in Asian patients with vitiligo is unknown. What does this study add? In contrast to white patients, the risk of both melanoma and NMSC was increased in Korean patients with vitiligo compared with controls. Owing to possible ethnic differences in susceptibility to skin cancer, skin cancer surveillance in the vitiligo population should be adjusted for race.

Anomalous Electron Dynamics Induced through the Valley Magnetic Domain: A Pathway to Valleytronic Current Processing.

An interplay between an applied strain and the Berry curvature reconstruction in the uniaxially strained monolayer MoS2 is explored that leads to the unbalanced Berry curvatures centered at K and -K points and, eventually, the valley magnetization under an external electric field. This is shown to explain a recent experimental observation of the valley magnetoelectric effect and develop a novel concept of the valley magnetic domain (VMD), i.e., a real-space homogeneous distribution of the valley magnetization. A realization of VMD guarantees a sufficient number of stable valley-polarized carriers, one of the most essential prerequisites of the valleytronics. Furthermore, we discover the anomalous electron dynamics through the VMD activation and achieve a manipulation of the anomalous transverse current perpendicular to the electric field, directly accessible to the signal processing [for instance, the current modulation under the VMD (i.e., the VMD wall) moving and the terahertz current rectification under the VMD switching]. This suggests a concept of VMD for use in providing new physical insight into the valleytronic functionality and its manipulation as a key ingredient of potential device applications.

Genomic screening of Fabry disease in young stroke patients: the Taiwan experience and a review of the literature.

BACKGROUND AND PURPOSE: Fabry disease is an X-linked disease, and enzyme-based screening methods are not suitable for female patients. METHODS: In total, 1000 young stroke patients (18-55 years, 661 with ischaemic stroke and 339 with hypertensive intracerebral hemorrhage) were recruited. The Sequenom iPLEX assay was used to detect 26 Fabry related mutation genes. The frequency of Fabry disease in young stroke was reviewed and compared between Asian and non-Asian countries. RESULTS: Two male patients with ischaemic stroke were found to have a genetic mutation of IVS4+919G>A. There was no α-galactosidase A (GLA) gene mutation in female patients. The frequency in Asian stroke patients was 0.62% (male vs. female 0.63% vs. 0.58%) with 0.72% for ischaemic stroke and none for hemorrhagic stroke, compared to 0.88% (0.77% vs. 1.08%) with 0.83% for ischaemic stroke and 1.40% for hemorrhagic stroke reported in western countries. CONCLUSION: IVS4+919G>A is the GLA mutation in Taiwanese young ischaemic stroke patients. Fabry disease is more frequent among non-Asian patients compared to Asian patients.

Severe opioid withdrawal precipitated by Vivitrol®.

The risk of severe precipitated opioid withdrawal (POW) is amplified when precipitated by a long-acting opioid antagonist. IM extended release naltrexone (XRNTX;Vivitrol®) is an FDA approved therapy to prevent relapse of opioid and alcohol abuse. Two cases of precipitated opioid withdrawal from XRNTX are presented that illustrate different patient reactions to POW. A 56-year-old woman developed a hypertensive emergency and required continuous intravenous vasodilator, clonidine, and intensive care monitoring after re-initiation of XRNTX following opioid relapse. A 25-year-old man developed agitation and altered mental status after receipt of XRNTX at the conclusion of a twelve-day detoxification program during which he continued surreptitious use of heroin. The patient received benzodiazepines and haloperidol without adequate affect, and required intubation with propofol, lorazepam, and dexmedetomidine infusions. Management of POW from XRNTX is a challenge to emergency providers and protocols to guide management do not exist. Recommended therapies include intravenous fluids, anti-emetics, clonidine, or benzodiazepines as well as therapy tailored to the organ system affected. To minimize risk of POW it is important for providers instituting XRNTX to adhere to the manufacturers warnings and clinic protocols including a naloxone challenge and ensure an adequate opioid free period prior to administration of XRNTX.

Two-dimensional semiconductors ZrNCl and HfNCl: Stability, electric transport, and thermoelectric properties.

Searching for novel two-dimensional (2D) semiconducting materials is a challenging issue. We investigate novel 2D semiconductors ZrNCl and HfNCl which would be isolated to single layers from van der Waals layered bulk materials, i.e., ternary transition-metal nitride halides. Their isolations are unquestionably supported through an investigation of their cleavage energies as well as their thermodynamic stability based on the ab initio molecular dynamics and phonon dispersion calculations. Strain engineering is found to be available for both single-layer (1L) ZrNCl and 1L-HfNCl, where a transition from an indirect to direct band gap is attained under a tensile strain. It is also found that 1L-ZrNCl has an excellent electron mobility of about 1.2 × 103 cm2 V-1 s-1, which is significantly higher than that of 1L-MoS2. Lastly, it is indicated that these systems have good thermoelectric properties, i.e., high Seebeck coefficient and high power factor. With these findings, 1L-ZrNCl and 1L-HfNCl would be novel promising 2D materials for a wide range of optoelectronic and thermoelectric applications.

Effects of halogens on European air-quality.

Halogens (Cl, Br) have a profound influence on stratospheric ozone (O3). They (Cl, Br and I) have recently also been shown to impact the troposphere, notably by reducing the mixing ratios of O3 and OH. Their potential for impacting regional air-quality is less well understood. We explore the impact of halogens on regional pollutants (focussing on O3) with the European grid of the GEOS-Chem model (0.25° × 0.3125°). It has recently been updated to include a representation of halogen chemistry. We focus on the summer of 2015 during the ICOZA campaign at the Weybourne Atmospheric Observatory on the North Sea coast of the UK. Comparisons between these observations together with those from the UK air-quality network show that the model has some skill in representing the mixing ratios/concentration of pollutants during this period. Although the model has some success in simulating the Weybourne ClNO2 observations, it significantly underestimates ClNO2 observations reported at inland locations. It also underestimates mixing ratios of IO, OIO, I2 and BrO, but this may reflect the coastal nature of these observations. Model simulations, with and without halogens, highlight the processes by which halogens can impact O3. Throughout the domain O3 mixing ratios are reduced by halogens. In northern Europe this is due to a change in the background O3 advected into the region, whereas in southern Europe this is due to local chemistry driven by Mediterranean emissions. The proportion of hourly O3 above 50 nmol mol-1 in Europe is reduced from 46% to 18% by halogens. ClNO2 from N2O5 uptake onto sea-salt leads to increases in O3 mixing ratio, but these are smaller than the decreases caused by the bromine and iodine. 12% of ethane and 16% of acetone within the boundary layer is oxidised by Cl. Aerosol response to halogens is complex with small (∼10%) reductions in PM2.5 in most locations. A lack of observational constraints coupled to large uncertainties in emissions and chemical processing of halogens make these conclusions tentative at best. However, the results here point to the potential for halogen chemistry to influence air quality policy in Europe and other parts of the world.

Acceptability and effectiveness of a web-based psychosocial intervention among criminal justice involved adults.

BACKGROUND: The acceptability, feasibility and effectiveness of web-based interventions among criminal justice involved populations are understudied. This study is a secondary analysis of baseline characteristics associated with criminal justice system (CJS) status as treatment outcome moderators among participants enrolling in a large randomized trial of a web-based psychosocial intervention (Therapeutic Education System [TES]) as part of outpatient addiction treatment. METHODS: We compared demographic and clinical characteristics, TES participation rates, and the trial's two co-primary outcomes, end of treatment abstinence and treatment retention, by self-reported CJS status at baseline: 1) CJS-mandated to community treatment (CJS-mandated), 2) CJS-recommended to treatment (CJS-recommended), 3) no CJS treatment mandate (CJS-none). RESULTS: CJS-mandated (n = 107) and CJS-recommended (n = 69) participants differed from CJS-none (n = 331) at baseline: CJS-mandated were significantly more likely to be male, uninsured, report cannabis as the primary drug problem, report fewer days of drug use at baseline, screen negative for depression, and score lower for psychological distress and higher on physical health status; CJS-recommended were younger, more likely single, less likely to report no regular Internet use, and to report cannabis as the primary drug problem. Both CJS-involved (CJS -recommended and -mandated) groups were more likely to have been recently incarcerated. Among participants randomized to the TES arm, module completion was similar across the CJS subgroups. A three-way interaction of treatment, baseline abstinence and CJS status showed no associations with the study's primary abstinence outcome. CONCLUSIONS: Overall, CJS-involved participants in this study tended to be young, male, and in treatment for a primary cannabis problem. The feasibility and effectiveness of the web-based psychosocial intervention, TES, did not vary by CJS-mandated or CJS-recommended participants compared to CJS-none. Web-based counseling interventions may be effective interventions as US public safety policies begin to emphasize supervised community drug treatment over incarceration.

New Method to Determine the Schottky Barrier in Few-Layer Black Phosphorus Metal Contacts.

Schottky barrier height and carrier polarity are seminal concepts for a practical device application of the interface between semiconductor and metal electrode. Investigation of those concepts is usually made by a conventional method such as the Schottky-Mott rule, incorporating the metal work function and semiconductor electron affinity, or the Fermi level pinning effect, resulting from the metal-induced gap states. Both manners are, however, basically applied to the bulk semiconductor metal contacts. To explore few-layer black phosphorus metal contacts far from the realm of bulk, we propose a new method to determine the Schottky barrier by scrutinizing the layer-by-layer phosphorus electronic structure from the first-principles calculation combined with the state-of-the-art band unfolding technique. In this study, using the new method, we calculate the Schottky barrier height and determine the contact polarity of Ti, Sc, and Al metal contacts to few-layer (mono-, bi-, tri-, and quadlayer) black phosphorus. This gives a significant physical insight toward the utmost layer-by-layer manipulation of electronic properties of few-layer semiconductor metal contacts.

Schottky barrier tuning of the single-layer MoS2 on magnetic metal substrates through vacancy defects and hydrogenation.

For the practical device application of the two-dimensional semiconducting MoS2, it is a critical issue to manipulate the electronic and magnetic properties locally at its contact to the metal electrode. For the tuning of those properties, we have proposed the vacancy-defective 1L-MoS2 or the hydrogenated 1L-MoS2 at the metal [Co(0001) or Ni(111)] contacts and performed first-principles electronic structure calculations. By controlling the atomic vacancy defects and the hydrogen coverages, we investigate the Schottky barrier heights and charge and spin transfers at the interface. Our findings provide a physical insight into the practical device design using the two-dimensional MoS2.

Recent Internet Use and Associations with Clinical Outcomes among Patients Entering Addiction Treatment Involved in a Web-Delivered Psychosocial Intervention Study.

The acceptability and clinical impact of a web-based intervention among patients entering addiction treatment who lack recent internet access are unclear. This secondary analysis of a national multisite treatment study (NIDA Clinical Trials Network-0044) assessed for acceptability and clinical impact of a web-based psychosocial intervention among participants enrolling in community-based, outpatient addiction treatment programs. Participants were randomly assigned to 12 weeks of a web-based therapeutic education system (TES) based on the community reinforcement approach plus contingency management versus treatment as usual (TAU). Demographic and clinical characteristics, and treatment outcomes were compared among participants with recent internet access in the 90 days preceding enrollment (N = 374) and without internet access (N = 133). Primary outcome variables included (1) acceptability of TES (i.e., module completion; acceptability of web-based intervention) and (2) clinical impact (i.e., self-reported abstinence confirmed by urine drug/breath alcohol tests; retention measured as time to dropout). Internet use was common (74 %) and was more likely among younger (18-49 years old) participants and those who completed high school (p < .001). Participants randomized to TES (n = 255) without baseline internet access rated the acceptability of TES modules significantly higher than those with internet access (t = 2.49, df = 218, p = .01). There was a near significant interaction between treatment, baseline abstinence, and internet access on time to dropout (χ 2(1) = 3.8089, p = .051). TES was associated with better retention among participants not abstinent at baseline who had internet access (X 2(1) = 6.69, p = .01). These findings demonstrate high acceptability of this web-based intervention among participants that lacked recent internet access.

Topological band-order transition and quantum spin Hall edge engineering in functionalized X-Bi(111) (X = Ga, In, and Tl) bilayer.

Functionalized X-Bi bilayers (X = Ga, In, and Tl) with halogens bonded on their both sides have been recently claimed to be the giant topological insulators due to the strong band inversion strengths. Employing the first-principles electronic structure calculation, we find the topological band order transition from the order p - p - s of the X-Bi bilayers with halogens on their both sides to the new order p - s - p of the bilayers (especially for X = Ga and In) with halogen on one side and hydrogen on the other side, where the asymmetric hydrogen bonding simulates the substrate. We further find that the p - s bulk band gap of the bilayer bearing the new order p - s - p sensitively depends on the electric field, which enables a meaningful engineering of the quantum spin Hall edge state by controlling the external electric field.

Rectifying the Optical-Field-Induced Current in Dielectrics: Petahertz Diode.

Investigating a theoretical model of the optical-field-induced current in dielectrics driven by strong few-cycle laser pulses, we propose an asymmetric conducting of the current by forming a heterojunction made of two distinct dielectrics with a low hole mass (m_{h}^{*}≪m_{e}^{*}) and low electron mass (m_{e}^{*}≪m_{h}^{*}), respectively. This proposition introduces the novel concept of a petahertz (10^{15} Hz) diode to rectify the current in the petahertz domain, which should be a key ingredient for the electric signal manipulation of future light-wave electronics. Further, we suggest the candidate dielectrics for the heterojunction.

Effect of family caregiver oral care training on stroke survivor oral and respiratory health in Taiwan: a randomised controlled trial.

OBJECTIVE: To evaluate the effectiveness of home-based oral care training programs on tongue coating (TC), dental plaque (DP), and symptoms of respiratory infection (SRI) in stroke survivors. METHODS: A single-blind, randomised, controlled trial conducted in a home-based setting over 2 months. Stroke survivors (n=48, experimental group) and their family caregivers received home-based oral care training programme while a control group of 46 stroke survivors and family caregivers received routine oral care education with swabs. TC, DP, and SRI were assessed at baseline and after one and two months, with results analysed using Mixed Model ANOVA. RESULTS: Poor oral hygiene and overall neglect of home oral care practices were observed at baseline. TC and DP scores were significantly reduced in the experimental group receiving the home-base oral care training program compared to the control group, who received only routine oral care education (P<0.001). The groupxtime interaction was significant, with decreased TC and DP scores for both groups at one month and at two months of additional care (when compared to baseline). The SRI scores were not significantly different between groups (P>0.05). The groupxtime interaction did not correlate with SRI for either group when compared to the baseline and to one month and two months of additional care. No adverse events were encountered and there was no external funding. CONCLUSIONS: Home-based oral care training programme had a beneficial effect on oral health as measured by TC and DP scores. The effect on SRI requires further longitudinal study.

Enterobacter asburiae KE17 association regulates physiological changes and mitigates the toxic effects of heavy metals in soybean.

This study aimed to elucidate the role played by Enterobacter asburiae KE17 in the growth and metabolism of soybeans during copper (100 µm Cu) and zinc (100 µm Zn) toxicity. When compared to controls, plants grown under Cu and Zn stress exhibited significantly lower growth rates, but inoculation with E. asburiae KE17 increased growth rates of stressed plants. The concentrations of plant hormones (abscisic acid and salicylic acid) and rates of lipid peroxidation were higher in plants under heavy metal stress, while total chlorophyll, carotenoid content and total polyphenol concentration were lower. While the bacterial treatment reduced the abscisic acid and salicylic acid content and lipid peroxidation rate of Cu-stressed plants, it also increased the concentration of photosynthetic pigments and total polyphenol. Moreover, the heavy metals induced increased accumulation of free amino acids such as aspartic acid, threonine, serine, glycine, alanine, leucine, isoleucine, tyrosine, proline and gamma-aminobutyric acid, while E. asburiae KE17 significantly reduced concentrations of free amino acids in metal-affected plants. Co-treatment with E. asburiae KE17 regulated nutrient uptake by enhancing nitrogen content and inhibiting Cu and Zn accumulation in soybean plants. The results of this study suggest that E. asburiae KE17 mitigates the effects of Cu and Zn stress by reprogramming plant metabolic processes.

Intensive care unit-acquired blood stream infections: a 5-year retrospective analysis of a single tertiary care hospital in Korea.

PURPOSE: Bloodstream infections (BSIs) are serious complications with high mortality and morbidity in patients with critical illness. This study was conducted to analyze the clinical and microbiological characteristics as well as outcomes in patients with intensive care unit (ICU)-acquired BSIs. METHODS: Data from 1,545 patients admitted to the ICU were retrospectively collected from January 2005 to December 2010. ICU-acquired BSI was defined as a positive blood culture for a clinically significant bacterial or fungal pathogen obtained >72 h after admission to the ICU. Data on clinical and demographic characteristics, comorbid illness, causes of infections, causative pathogens, and clinical outcomes were analyzed. RESULTS: Among the 1,545 ICU patients analyzed, 129 ICU-acquired BSIs occurred in 124 patients. Catheter-related BSIs (CR-BSIs) and ventilator-associated pneumonia (VAP) were the most common causes (29.4 and 20.9%, respectively). The most common isolates were Staphylococcus aureus in 35 (25.7%) and Candida species in 32 (24.8%) cases. Ninety-eight patients died (overall hospital mortality rate, 75.9%). ICU-acquired BSI-related mortality occurred in 23 (63.8%) and 7 (19.4%) of the VAP and CR-BSIs cases, respectively. The most commonly isolated microorganisms from these fatalities were S. aureus (12, 25.7%) and Acinetobacter species (12, 25.7%). In 99 ICU-acquired BSI cases, patients did not receive adequate empirical antimicrobial treatment at the onset of BSIs, whereas the patients in 30 cases did. CONCLUSION: ICU-acquired BSIs may be associated with high mortality in patients with critical illness. Meticulous infection control and adequate treatment may reduce ICU-acquired BSI-related mortality.

Unexpected strong magnetism of Cu doped single-layer MoS2 and its origin.

The magnetism of the 3d transition-metal (TM) doped single-layer (1L) MoS2, where the Mo atom is partially replaced by the 3d TM atom, is investigated using the first-principles density functional calculations. In a series of 3d TM doped 1L-MoS2's, the induced spin polarizations are negligible for Sc, Ti, and Cr dopings, while the induced spin polarizations are confirmed for V, Mn, Fe, Co, Ni, Cu, and Zn dopings and the systems become magnetic. Especially, the Cu doped system shows unexpectedly strong magnetism although Cu is nonmagnetic in its bulk state. The driving force is found to be a strong hybridization between Cu 3d states and 3p states of neighboring S, which results in an extreme unbalanced spin-population in the spin-split impurity bands near the Fermi level. Finally, we also discuss further issues of the Cu induced magnetism of 1L-MoS2 such as investigation of additional charge states, the Cu doping at the S site instead of the Mo site, and the Cu adatom on the layer (i.e., 1L-MoS2).