Determination and investigation of defect domains in multi-shape monolayer tungsten disulfide.

Single-layer tungsten disulfide (WS2) is among the most widely investigated two-dimensional materials. Synthesizing it over large areas would enable the exploitation of its appealing optical and electronic properties in industrial applications. However, defects of different nature, concentration and distribution profoundly affect the optical as well as the electronic properties of this crystal. Controlling the defect density distribution can be an effective way to tailor the local dielectric environment and therefore the electronic properties of the system. In this work we investigate the defects in single-layer WS2, grown in different shapes by liquid phase chemical vapor deposition, where the concentration of certain defect species can be controlled by the growth conditions. The properties of the material are surveyed by means of optical spectroscopy, photoelectron spectroscopy and Kelvin probe force microscopy. We determine the chemical nature of the defects and study their influence on the optical and electronic properties of WS2. This work contributes to the understanding of the microscopic nature of the intrinsic defects in WS2, helping the development of defect-based technologies which rely on the control and engineering of defects in dielectric 2D crystals.

Microscopic Understanding of Ultrafast Charge Transfer in van der Waals Heterostructures.

Van der Waals heterostructures show many intriguing phenomena including ultrafast charge separation following strong excitonic absorption in the visible spectral range. However, despite the enormous potential for future applications in the field of optoelectronics, the underlying microscopic mechanism remains controversial. Here we use time- and angle-resolved photoemission spectroscopy combined with microscopic many-particle theory to reveal the relevant microscopic charge transfer channels in epitaxial WS_{2}/graphene heterostructures. We find that the timescale for efficient ultrafast charge separation in the material is determined by direct tunneling at those points in the Brillouin zone where WS_{2} and graphene bands cross, while the lifetime of the charge separated transient state is set by defect-assisted tunneling through localized sulphur vacancies. The subtle interplay of intrinsic and defect-related charge transfer channels revealed in the present work can be exploited for the design of highly efficient light harvesting and detecting devices.

Temperature-Dependent Bending Rigidity of AB-Stacked Bilayer Graphene.

The change in bending rigidity with temperature κ(T) for 2D materials is highly debated: theoretical works predict both increase and decrease. Here we present measurements of κ(T), for a 2D material: AB-stacked bilayer graphene. We obtain κ(T) from phonon dispersion curves measured with helium atom scattering in the temperature range 320-400 K. We find that the bending rigidity increases with temperature. Assuming a linear dependence over the measured temperature region we obtain κ(T)=[(1.3±0.1)+(0.006±0.001)T/K] eV by fitting the data. We discuss this result in the context of existing predictions and room temperature measurements.

Patterned tungsten disulfide/graphene heterostructures for efficient multifunctional optoelectronic devices.

One of the major issues in graphene-based optoelectronics is to scale-up high-performing devices. In this work, we report an original approach for the fabrication of efficient optoelectronic devices from scalable tungsten disulfide (WS2)/graphene heterostructures. Our approach allows for the patterned growth of WS2 on graphene and facilitates the realization of ohmic contacts. Photodetectors fabricated with WS2 on epitaxial graphene on silicon carbide (SiC) present, when illuminated with red light, a maximum responsivity R ∼220 A W-1, a detectivity D* ∼2.0 × 109 Jones and a -3 dB bandwidth of 250 Hz. The retrieved detectivity is 3 orders of magnitude higher than that obtained with graphene-only devices at the same wavelength. For shorter illumination wavelengths we observe a persistent photocurrent with a nearly complete charge retention, which originates from deep trap levels in the SiC substrate. This work ultimately demonstrates that WS2/graphene optoelectronic devices with promising performances can be obtained in a scalable manner. Furthermore, by combining wavelength-selective memory, enhanced responsivity and fast detection, this system is of interest for the implementation of 2d-based data storage devices.

Evidence for superconductivity in Li-decorated monolayer graphene.

Monolayer graphene exhibits many spectacular electronic properties, with superconductivity being arguably the most notable exception. It was theoretically proposed that superconductivity might be induced by enhancing the electron-phonon coupling through the decoration of graphene with an alkali adatom superlattice [Profeta G, Calandra M, Mauri F (2012) Nat Phys 8(2):131-134]. Although experiments have shown an adatom-induced enhancement of the electron-phonon coupling, superconductivity has never been observed. Using angle-resolved photoemission spectroscopy (ARPES), we show that lithium deposited on graphene at low temperature strongly modifies the phonon density of states, leading to an enhancement of the electron-phonon coupling of up to λ ≃ 0.58. On part of the graphene-derived π*-band Fermi surface, we then observe the opening of a Δ ≃ 0.9-meV temperature-dependent pairing gap. This result suggests for the first time, to our knowledge, that Li-decorated monolayer graphene is indeed superconducting, with Tc ≃ 5.9 K.

Spine bone texture assessed by trabecular bone score (TBS) to evaluate bone health in thalassemia major.

Due to the increasing survival of thalassemic patients, osteopathy is a mounting clinical problem. Low bone mass alone cannot account for the high fracture risk described; impaired bone quality has been speculated but so far it cannot be demonstrated noninvasively. We studied bone quality in thalassemia major using trabecular bone score (TBS), a novel texture measurement extracted from spine dual-energy X-ray absorptiometry (DXA), proposed in postmenopausal and secondary osteoporosis as an indirect index of microarchitecture. TBS was evaluated in 124 adult thalassemics (age range 19-56 years), followed-up with optimal transfusional and therapeutical regimens, and in 65 non-thalassemic patients (22-52 years) undergoing DXA for different bone diseases. TBS was lower in thalassemic patients (1.04 ± 0.12 [range 0.80-1.30]) versus controls (1.34 ± 0.11 [1.06-1.52]) (p < 0.001), and correlated with BMD. TBS and BMD values correlated with age, indicating that thalassemia negatively affects both bone quality and quantity, especially as the patient gets older. TBS was 1.02 ± 0.11 [0.80-1.28] in the osteoporotic thalassemic patients, 1.08 ± 0.12 [0.82-1.30] in the osteopenic ones and 1.15 ± 0.10 [0.96-1.26] in those with normal BMD. No gender differences were found (males: 1.02 ± 0.13 [0.80-1.30], females 1.05 ± 0.11 [0.80-1.30]), nor between patients with and without endocrine-metabolic disorders affecting bone metabolism. Our findings from a large population with thalassemia major show that TBS is a valuable tool to assess noninvasively bone quality, and it may be related to fragility fracture risk in thalassemic osteopathy.

Thalassemic osteopathy: a new marker of bone deposition.

Osteopathy represents a prominent cause of morbidity in patients with beta-thalassemia major (TM) and manifests as osteopenia/osteoporosis. Biochemical turnover markers (BTMs) are considered a useful, non-invasive tool for the clinical follow-up of osteoporotic patients; they can provide a dynamic view of the remodeling process and give information on the metabolic activity of bone tissue as well as on the pathogenesis of bone loss. The amino-terminal pro-peptide of type I procollagen (P1NP) is a recently introduced marker that is considered the most sensitive index of bone formation. Although demonstrated in several categories of patients with bone disease, there is little information on the clinical usefulness of this bone formation index in thalassemic patients. We evaluated the P1NP levels of 53 adult patients with b-thalassemia major (21 males and 32 females, mean age 34.5 ± 5.7, range 22-46 years) and associated osteopathy. We investigated the correlation between P1NP and bone condition as examined by dual X-ray photon absorptiometry and with BTMs expressing bone resorption and bone mineralization (carboxyterminal collagen cross-linked (CTX) terminal regions of type I collagen and osteocalcin, respectively). P1NP serum levels were correlated with CTX levels (r=0.545, p<0.001); the results were unchanged when males and females, as well as osteoporotic and osteopenic subgroups, were considered separately. No correlation was demonstrated neither between OC and CTX (r=0.17, p=ns), nor between P1NP and OC levels (r=0.11, p=ns). No correlation was demonstrated among the P1NP/CTX ratio and age, OC or densitometric values and no difference was found in the same ratio between osteopenic (0.19 ± 0.16) and osteoporotic (0.15 ± 0.14) patients. Similar results were obtained for the OC/CTX ratio, as it was not correlated with age, P1NP or densitometric values. This is the first report of circulating P1NP in patients with TM-associated osteoporosis. P1NP and CTX assays show good precision and low analytical CV, and, compared to other markers, they can acceptably reflect bone metabolic processes and promptly respond to antiosteoporotic treatments. We trust that this sensitive marker can be useful in the assessment of treatment efficacy and can overcome the pitfalls due to wide variability in the normal values of most BTMs that create difficulty in pinpointing the individual patient's response.

Adatoms and clusters of 3d transition metals on graphene: electronic and magnetic configurations.

We investigate the electronic and magnetic properties of single Fe, Co, and Ni atoms and clusters on monolayer graphene (MLG) on SiC(0001) by means of scanning tunneling microscopy (STM), x-ray absorption spectroscopy, x-ray magnetic circular dichroism (XMCD), and ab initio calculations. STM reveals different adsorption sites for Ni and Co adatoms. XMCD proves Fe and Co adatoms to be paramagnetic and to exhibit an out-of-plane easy axis in agreement with theory. In contrast, we experimentally find a nonmagnetic ground state for Ni monomers while an increasing cluster size leads to sizeable magnetic moments. These observations are well reproduced by our calculations and reveal the importance of hybridization effects and intra-atomic charge transfer for the properties of adatoms and clusters on MLG.

Effect of eye lateralization on contralateral suppression of transient evoked otoacoustic emissions.

Several studies have previously demonstrated that postural changes modify evoked otoacoustic emission. In order to evaluate a possible interaction between eye muscles and ciliated cells in the inner ear, we studied the effects of eye lateralization on the contralateral suppression of transient evoked otoacoustic emissions (TEOAEs). Thirty-eight normal hearing subjects with TEOAEs were recruited. Their TEAOEs at threshold level were recorded with contralateral suppression (white noise) via straight ahead fixation and right or left lateral fixation. Eye lateralization in the same direction of the white noise significantly decreased the suppression at 4 kHz (p = 0.003). The signal-to-noise ratio in the suppression condition with straight ahead was 1.54 (± 4.610) dB, while the ratio was 3.48 (± 4.631) dB in the suppression condition with gaze toward the white noise. Eye lateralization seems to reduce the contralateral suppression effect of TEOAEs at 4 kHz. However, further studies are necessary to investigate the possible mechanisms of this phenomenon.

Outcomes of structural fat grafting for paralytic and non-paralytic dysphonia.

Aims of this prospective study were to evaluate the results of vocal fold structural fat grafting for glottic insufficiency and to compare the outcomes obtained in unilateral vocal fold paralysis (UVFP) and congenital or acquired soft tissue defects in vocal folds. Sixty-six consecutive patients with breathy dysphonia, in 43 cases (aged 16-79 years) related to UVFP and in 23 cases (aged 16-67 years) related to vocal fold iatrogenic scar or sulcus vocalis, underwent autologous structural fat grafting into vocal folds. Lipoaspirates were centrifuged at 1200 g for 3 min to separate and remove blood, cell debris and the oily layer. The refined fat was injected under direct microlaryngoscopy in a multilayered way. The main outcome measures were grade, roughness, breathiness, asthenicity and strain (GRBAS) perceptual evaluation, maximum phonation time (MPT), self-assessed Voice Handicap Index (VHI), and voice acoustic analysis, considered pre-operatively and at 3 and 6 months after fat grafting. After surgery, MPT, VHI, G and B improved in both groups (p < 0.05). In particular, G and VHI functional subscales showed a significantly greater decrease in patients with UVFP (p < 0.05). The acoustic variables improved significantly only in the UVFP group (p < 0.005). From 3 to 6 months postoperatively, most variables showed a trend with further improvement. Vocal fold structural fat grafting was significantly effective in treating glottic insufficiency due to UVFP or soft tissue defects. Perceptual, acoustic and subjective assessments confirmed that patients with UVFP had better outcomes than those with soft tissue defects.

Efficacy of complex herbal compound of Echinacea angustifolia (Imoviral® Junior) in recurrent upper respiratory tract infections during pediatric age: preliminary results.

AIM: Among pediatric population the recurrent upper respiratory tract infections are very common. Several phytotherapies are been proposed as support therapies and, in particular, the efficacy of Echinacea angustifolia is controversial. This paper presents an evaluation of a new herbal compound in the treatment of recurrent upper respiratory tract infections in a pediatric cohort. METHODS: An immunostimulant herbal compound of Echinacea angustifolia, Arabinogalactan, Acerola (Vitamin C), Beta- Glucan e Zinc (Imoviral® Junior) was given to 37 children affected by recurrent pharyngotonsillitis or otitis media. RESULTS: The mean number of inflammatory episodes (i.e. tonsillitis or otitis media) during 6 months before treatment was 3±2.19, during the 6 months following treatment initiation it was 1±0.93 (P=0.04). After the complete treatment, 77% of children reported an improvement of chronic inflammatory in frequency of acute episodes. The total score of a questionnaire about life quality is improved (P=0.04). Finally, none collateral effects was occurred. CONCLUSION: The herbal compound of echinacea, beta-glucan, vitamin c, arabinoglactan and zinc (Imoviral® Junior) can improve the quality of life in pediatric patients affected by recurrent pharyngotonsillitis and otitis media without contralateral effects.

A comparison between metabolic syndrome post-hematopoietic stem cell transplantation and spontaneously occurring metabolic syndrome.

BACKGROUND: Hematopoietic stem cell transplantation (HSCT) is used in the treatment of several hematological and non-hematological disorders. An increasing number of long-term survivors recover from their primary disease, but they are at risk of adverse late effects, including metabolic syndrome (MS), which seems to be common in long-term survivors of HSCT. AIM: To compare common metabolic parameters and adipohormone profiles in post-transplant and spontaneously occurring or "classic" MS patients. SUBJECTS AND METHODS: Post-transplant MS patients (15 women and 14 men; 49.8±9.3 yr) were compared to "classic" MS patients (15 women and 14 men; 52.9±8.0 yr). For each subject a record of conventional clinical parameters was made; moreover, serum leptin, insulin, quantitative C-reactive protein (CRP), tumor necrosis factor-α [TNF-α], and adiponectin concentrations were measured. RESULTS: The patients with post-HSCT MS had significantly higher levels of leptin, CRP, and TNF-α than the patients with "classic" MS. A generalized linear model comprising serum insulin (p=0.022), body mass index (p<0.001), gender (p<0.001), and group (i.e. healthy, post-HSCT with MS, or suffering from "classic" MS; p<0.001) explained serum leptin variability (adjusted R(2)=0.741). Serum leptin concentrations and BMI were related in the patients with "classic" MS but not in those with post-HSCT MS. CONCLUSIONS: A possible pathogenetic mechanism in the development of MS after HSCT could be hyperleptinemia. A potential interaction among circulating leptin, components of MS, and immune function might explain the role of this adipokine in mediating cardiovascular risk after HSCT.

Tinnitus sound therapy with open ear canal hearing aids.

OBJECTIVE: The aims of this study were to evaluate the efficacy of open ear canal hearing aids in tinnitus treatment and to investigate the influence of gender, age, medication usage, tinnitus cause, tinnitus perception side, tinnitus pitch, pure tone audiometry, distortion product otoacoustic emissions, and minimal masking level on outcome. METHODOLOGY: One hundred tinnitus patients were evaluated by the tinnitus handicap inventory (THI) at the beginning of the study and after nine months of treatment. All subjects were submitted to counselling and sound enrichment from the simple sound amplification provided by the open ear canal hearing aids. RESULTS: Initial mean THI score was 54.22 (+/- 20.37) and final mean score was 28.32 (+/- 16.50), p < 0.0001. No statistically significant correlations were found between THI value reduction and the studied parameters. CONCLUSION: Open ear canal hearing aids were useful in all tinnitus patients with mild hearing loss.

Are results of tinnitus retraining therapy maintained over time? 18-month follow-up after completion of therapy.

Tinnitus retraining therapy (TRT) is a useful treatment for tinnitus. The aim of this study was to evaluate the results obtained after 18 months of TRT as well as 18 months after completion of therapy, i.e. 36 months after initiation of TRT. Forty-five subjects suffering from an idiopathic tinnitus with or without hyperacusis for at least 6 months were recruited. There were significant improvements during therapy (p < 0.001) and the mean Tinnitus Handicap Inventory (THI) was lowered by more than 20 points. These improvements persisted 18 months after treatment completion. Furthermore, the percentage of patients reporting the disappearance of their difficulties in various activities (relaxation, concentration, sleep, social relations and work) increased continuously after treatment completion. TRT improved self-perceived disability induced by chronic tinnitus for a long time after the end of therapy.

Development and daily use of an electronic oncological patient record for the total management of cancer patients: 7 years' experience.

BACKGROUND: We describe our experience with an electronic oncological patient record (EOPR) for the total management of cancer patients. METHODS: The web-based EOPR was developed on the basis of a user-centred design including user education and training, followed by continuous assistance; user acceptance was monitored by means of three questionnaires administered after 2 weeks, 6 months and 6 years. RESULTS: The EOPR has been used daily for all in-ward, day hospital and ambulatory clinical activities since July 2000. The most widely appreciated functions are its rapid multipoint access, the self-updated summary of the patients' clinical course, the management of the entire therapeutic programme synchronised with working agendas and oncological teleconsultation. Security and privacy are assured by means of the separate storage of clinical and demographic data, with access protected by login and a password. The questionnaires highlighted appreciation of rapid data retrieval and exchange and the perception of improved quality of care, but also revealed a sense of additional work and a negative impact on doctor-patient relationships. CONCLUSIONS: Our EOPR has proved to be effective in the total management of cancer patients. Its user-centred design and flexible web technology have been key factors in its successful implementation and daily use.

Narrowband UVB phototherapy in vitiligo: evaluation of results in 53 patients.

AIM: Narrowband UVB (NBUVB)phototherapy has been used for vitiligo for years, but today there are no standardized protocols of treatment and follow-up data. A long-term study on 53 patients with localized or diffuse vitiligo is presented with the aim at improving the data availability in the literature. METHODS: Phototherapy was administered two times a week on non-consecutive days; the treatment was continued for one year. The mean total dose administered was 201.28 J/cm2.The response to phototherapy was expressed as percentage of repigmentation: a repigmentation greater than 75% was considered excellent, a repigmentation between 74% and 50% good, a repigmentation between 49% and 25% moderate, a repigmentation less than 24% mild. In case of absence of repigmentation, the patient was judged as non-responder RESULTS: Three point eight percent of patients showed excellent response, 32.05% good response, 32.05% moderate response, 28.3% mild response, while the remaining 3.8% was not responsive. According to statistical analysis best responses, were observed in non-acral areas (P<0.001), in patients with recent vitiligo (P=0.003), in patients with negative family history for vitiligo (P=0.038), and in those not exposed to previous therapies (P=0.005). In 36 patients a mean follow-up of 19.78 months was obtained. CONCLUSION: NBUVB phototherapy is useful and safe for vitiligo, but in the future it will be necessary to compare results of different studies using the same treatment protocols and to obtain data of series endowed with an adequate follow-up.

Prevalence of metabolic syndrome in long-term survivors of hematopoietic stem cell transplantation.

Our purpose was to determine the prevalence and features of metabolic syndrome (MS) in a series of long-term hematopoietic stem cell transplantation (HSCT) survivors. We assessed the clinical, metabolic and endocrinological data, and plasma TNF, leptin, resistin and adiponectin levels relating to 85 HSCT recipients. MS was diagnosed on the basis of the National Cholesterol Education Program-Adult Treatment Panel III criteria. Its prevalence was compared with that observed in an Italian population, and its relationship with the clinical and laboratory parameters was assessed univariately and multivariately. Twenty-nine HSCT recipients had MS instead of the 12.8 expected (P<0.0001), with hypertriglyceridemia being the most common feature. Univariate analysis indicated that high insulin and leptin levels, low-adiponectin levels and hypogonadism were significantly related to a diagnosis of MS; multivariate analysis indicated plasma leptin, insulin resistance, age and hypogonadism. We conclude that HSCT recipients are at increased risk of a form of MS that has particular clinical features. Plasma leptin levels are independently related to MS, thus suggesting that leptin resistance may play a role as a pathogenetic clue, as in other conditions in which MS occurs as a secondary phenomenon. MS deserves consideration as a life-threatening complication in patients who are probably cured of their underlying disease.

[Computer terminals. Evaluation of utilization time]. / Valutazione dei tempi di utilizzo del videoterminale.

The aim of the present study was to compare the duration of computer use assessed through a software package and through self-report by questionnaire. Applied in a large Public Administration the software package led altogether to a remarkable reduction in the number of workers reaching the duration of use which requires medical examination. Nevertheless, it highlighted that self-reporting of a considerable number of workers had underestimated the computer use. The consistency with Italian laws is also discussed.