Improvements of optical tactile sensors for robotic system by gold nanocomposite material.

In this work we propose the evolution of a new class of optical pressure sensors suitable for robot tactile sensing. The sensors are based on a tapered optical fiber, where optical signals travel embedded into a PDMS-gold nanocomposite material. By applying different pressure forces on the PDMS-based nanocomposite we measure in real time the change of the optical transmitted intensity due to the coupling between the gold nanocomposite material and the tapered fiber region. The intensity reduction of the transmitted light intensity is correlated with the pressure force magnitude.

Wettability control by laser texturing process generating localized gold nanoparticles on polymeric thin films.

In this work a new approach is introduced for surface properties control by laser texturing process. By UV laser irradiation, we are able to control the surface wettability of a chitosan polymeric film in which is introduced a chloroauric acid salt by immersion. Specifically the UV irradiation is responsible for the creation of gold nanoparticles at the irradiated surface of the polymeric film. This photolytic process allows us to localize and design accurately surface patterns and moreover to tune metallic particle size in the range of nanoscale. After the characterization of our gold textured surfaces by atomic force and scanning electron microscopies, we demonstrate the link between wettability surface properties and gold nanoparticles size. The experimental results indicate the influence of the laser intensity, the irradiation time and the polymer film thickness (by increasing the gold concentration) on the gold nanoparticle density and size.

Efficient and wideband horn nanoantenna.

In this Letter, we present the design of a horn nanoantenna working at near-IR frequencies. The proposed layout consists of an Ag-air-Ag nanotransmission line terminated in a tapered horn. The antenna design is validated through proper full-wave numerical simulations, taking into account actual dispersion and losses of the involved materials. The numerical results show that the designed nanohorn is matched over a broad range of frequencies (more than 50% of fractional bandwidth) and radiates efficiently in the same frequency band (the realized gain is greater than 10 dBi). Such promising results may find application in different technical and scientific fields, ranging from smart lighting to optical wireless communications.

Ustekinumab treatment for moderate-to-severe plaque psoriasis: eight-year real-life experience.

Background: Limited information is available from real-life studies evaluating the long-term efficacy and drug retention of ustekinumab.Research design and methods: Data from 378 patients with moderate-severe psoriasis were retrospectively analyzed. Over 8 years, disease severity and treatment response were evaluated using the PASI score. Predictors of PASI response were evaluated by logistic regression. Ustekinumab retention rate was calculated by the Kaplan-Meier method.Results: Over the 8 years, >80% of patients achieved a PASI score of <3 and PASI 75, 90 and 100 response was achieved in 76.2%, 61.9% and 57.1% of patients, respectively. Predictor variables for improved PASI response (after 2 years) were HLA-C*06-POS patients, female gender and BMI <30 Kg/M2. The 2-year retention rate was 81% and 59% after 8 years with mean retention rate of 5.4 years. Improved retention rate was observed in patients positive for the HLA-C*06 allele (3.7 vs. 2.5 years, p = 0.005) and female gender (3.7 vs. 3.3 years, p = 0.06), with no significant difference observed in other patient groups. Ustekinumab was generally well tolerated without evidence of cumulative toxicity or organ toxicity.Conclusion: The long-term use of ustekinumab was observed to be effective and safe in patients with moderate-severe chronic psoriasis in a real world-setting.

Novel grating design approach by radiation modes coupling in nonlinear optical waveguides.

In integrated optics the radiation modes represent a negative aspect regarding the propagation of guided modes. They characterize the losses of the substrate region but can contribute to enhance the guided modes by considering the coupling through properly designed gratings arranged at the core/substrate interface. By tailored gratings, the radiation modes become propagating modes and increase the guided power inside the waveguide guiding region. This enhancement is useful especially in low intensity processes such as second harmonic chi(2) conversion process. For this purpose, we analyze accurately the radiation modes contribution in a chi(2) GaAs/AlGaAs nonlinear waveguide where second harmonic signal is characterized by a low power intensity. This analysis considers a new design approach of multiple grating which enhances a fundamental guided mode at lambda(FU) =1.55 microm and a codirectional second harmonic guided mode at lambda(SH) =0.775 microm. In particular we analyze the second harmonic conversion efficiency by studying the coupling effect of three gratings. The combined effects of the gratings provide an efficient second harmonic field conversion. Design considerations, based on the coupled mode equations analysis, are theoretically discussed. A good agreement between analytical and numerical results is observed.

The neural cell adhesion molecule (NCAM) present in the cerebrospinal fluid of multiple sclerosis patients is unsialylated.

The neural cell adhesion molecule (NCAM) is a glycoprotein localised in the plasma membrane of neural and glial cells, which plays a role in myelination and remyelination. It increases in the cerebrospinal fluid (CSF) of acute multiple sclerosis (MS) patients treated with corticosteroids who are improving after an attack, but it has not been shown if it appears in its sialylated (PSA) or unsialylated form. We studied the NCAM and the PSA-NCAM in serum and CSF samples of 16 acute and non-acute MS patients and in the sera of 10 non-neurological controls. The NCAM and the PSA-NCAM were dosed by two different ELISA previously set-up. The NCAM in the serum and in the CSF of the control group presented mean levels similar to those shown in previous papers: 1620 +/- 216 and 970 +/- 210 ng/ml. In the MS patient group the means were 1700 +/- 546 in the sera and 926 +/- 285 in the CSFs. All the sera were PSA-NCAM-positive: the mean PSA-NCAM concentration in the control group was 3150 +/- 950 ng/ml, while in the MS patient group it was 3570 +/- 905 ng/ml. The correlation between serum levels of NCAM and PSA-NCAM was highly significant (p < 0.001). Student's "t" test did not show any significant difference between serum levels of the two groups, both for the NCAM and for the PSA-NCAM. CSF samples did not show any positive results for the PSA-NCAM, in either controls or in MS patients. These results demonstrate that the high levels of NCAM we previously found in the CSF of improving MS patients treated with steroids did not contain a quota of PSA-NCAM, but only the unsialylated soluble form of the molecule.

Spotlight on brodalumab in the treatment of plaque psoriasis: the evidence to date.

The IL-17/IL-23 axis is now understood to influence psoriasis, and the development of novel IL-17 inhibitor medications marks a sea change in the treatment of psoriasis. Brodalumab is a recombinant, fully human immunoglobulin IgG2 monoclonal antibody specifically targeted against IL-17RA. This article discusses the mechanism of action and the efficacy and safety profile of brodalumab presented in the literature. Brodalumab, the latest approved anti-IL-17-class medication, is the only one that exerts its effects on IL-17C as well as on IL-17A and IL-17F, blocking the shared IL-17 receptor A. In this sense, considering the recent evidence, brodalumab could have beneficial effects not only on psoriasis, but also on atopic dermatitis. It could also serve as a therapeutic alternative in patients who develop paradoxical eczematous reactions or atopic-like dermatitis during treatment with other anti-IL-17A (secukinumab, ixekizumab).

Pharmacotherapeutic management of psoriasis in adolescents and children.

Introduction: Psoriasis is a relatively common condition, with a lot of discordance in studies about the peak of onset. In a large German study, an almost linear prevalence increase was reported during childhood, ranging from 0.12% at 1 year to 1-2% at 18 years. According to recent studies, plaque psoriasis is the most common variant in childhood disease. Areas covered: This article focuses on topical, systemic and biologic therapies used in childhood psoriasis. The authors performed a full literature PubMed research, while incorporating case reports and experience. Topical agents are considered the first step, but they always have little efficacy in the extensive form of the disease. In this case, systemic and particularly biological therapy must be evaluated. The most studied treatment in the pediatric population is etanercept, but adalimumab and ustekinumab are also approved in pediatric and adolescent populations. Expert opinion: Larger studies are needed to further investigate the use of new compounds in childhood psoriasis. Recent evidence suggests that practitioners should consider interceding in the early immunologic psoriatic process to halt this march and stunt immunological scar development. An early investment would provide lasting effects and serious impact in long-term disease modification.

Scalar time domain modeling and coupling of second harmonic generation process in GaAs discontinuous optical waveguide.

We present in this work the scalar potential formulation of second harmonic generation process in chi((2)) nonlinear analysis. This approach is intrinsically well suited to the applications of the concept of circuit analysis and synthesis to nonlinear optical problems, and represents a novel alternative method in the analysis of nonlinear optical waveguide, by providing a good convergent numerical solution. The time domain modeling is applied to nonlinear GaAs asymmetrical waveguide with dielectric discontinuities in the hypothesis of quasi phase matching condition in order to evaluate the efficiency conversion of the second harmonic signal. The accuracy of the modeling is validated by the good agreement with the published experimental results. The effective dielectric constant method allows to extend the analysis also to 3D optical waveguides.

Ensuring signal quality of cerebral near infrared spectroscopy during continuous longterm monitoring.

BACKGROUND: Near infrared spectroscopy (NIRS) derived hemoglobin difference (HbD: oxygenated [HbO2] - reduced hemoglobin [Hb]) and total hemoglobin (HbT: HbO2+Hb) have been used as surrogate measures of cerebral blood flow and volume, respectively. Statistically, a lack of HbD-blood pressure (BP) or negative HbT-BP association is regarded as a state of intact cerebral pressure autoregulation (CPA). In contrast, a co-variation of HbD/HbT and systemic blood pressure (BP) in the same direction is thought of as a failure of CPA. If the quality of one (NIRS/BP) or both signals is compromised, the reliability of the results may be adversely affected. In this work, we develop an analytic approach to assess the quality of the NIRS signals. NEW METHOD: Given that cardiac pulses cause hemodynamic changes that are transmitted through the peripheral vasculature, cerebral NIRS signals should exhibit cyclical changes at the pulse frequency. Therefore, we propose that an association between HbD/HbT and electrocardiogram (EKG) signals would be an indicator of NIRS quality. We demonstrate the application of this approach with data collected from six newborns undergoing therapeutic hypothermia for neonatal encephalopathy. RESULTS: We observed an intermittent lack of association between NIRS signals and EKG data over the course of several hours of continuous records, indicating a loss in the strength in NIRS signals. COMPARISON WITH EXISTING METHOD: Existing CPA characterization suffers from Type-II error which the current preprocessing approach can mitigate. CONCLUSIONS: The proposed approach will allow for real-time assessment of NIRS signal quality that is essential for accurate CPA monitoring.

Design and modeling of tapered waveguide for photonic crystal slab coupling by using time-domain Hertzian potentials formulation.

This work introduces a new simulation approach to the evaluation of the time-domain electromagnetic (EM) field useful in the modeling of tapered waveguide for the Photonic Crystal Slab (PCS) coupling. Only solutions of two scalar Helmholtz-equations are used in the evaluation of electric and magnetic Hertzian-potentials that yields the EM field and the frequency response of the tapered waveguide. By considering simultaneously an analytical and a numerical approximation it is possible to reduce the computational burden. In order to compare the computational time we analyze the 2D structure by also using the Finite Difference Time Domain (FDTD) method and by the 3D Finite Element Method (FEM). The method is applied by starting from design criteria of the tapered structures in order to set the correct geometrical and physical parameters, and considers the field-perturbation effect in proximity of the dielectric discontinuities by generators modeling.

[(111)In]Pentetreotide SPECT scintigraphy in neuroendocrine tumors: variability of reconstructing parameters related to patient characteristics and each body part.

AIM: Multi-headvariable-geometry gammacamera, allow us to carry out multi-dimensional scintigraphic single photon emission computed tomography (SPECT) studies, with the possibility of creating coronal, axial, sagittal, three-dimensional images like the last generation of multi-slice RMI or multislice CT scan. The aim of this paper is to weigh up the reconstruction parameters to apply in [(0111)In]Pentetreotide scintigraphy for evaluating neuroendocrine tumors and try to standardize them. METHODS: We have studied a group of 93 patients suffering from neuroendocrine tumors. Examination was carried out after administration of [111In] Pentetreotide with whole body and static acquisitions after 4 and 24 h, followed by SPECT acquisitions of head, thorax and abdomen after 24 h. RESULTS: The results obtained show that the Filtered Back Projection using Butterworth filter can produce images of greater resolution than the iterative reconstruction method. Moreover, the reconstruction parameters are easily standardizable for head and thorax while for the abdomen the choice of these parameters is more difficult. CONCLUSIONS: Our data show that filtered back projection with Butterworth filter is the best procedure to carry out a SPECT examination with [111In] Pentetreotide.

Accurate planning of minimally invasive surgery of parathyroid adenomas by means of [(99m)Tc]MIBI SPECT.

AIM: The aim of the study was to evaluate the clinical role or [(99m)Tc]MIBI SPECT in selecting primary hyperparathyroid (PHPT) patients for minimally invasive radioguided surgery (MIRS). METHODS: One hundred and forty-one consecutive PHPT patients were studied by a single-session [(99m)Tc]Percethnetate/[(99m)Tc]MIBI subtraction scintigraphy, followed by [(99m)Tc]MIBI SPECT in order to localize hyperfunctioning parathyroid adenoma (PA) and plan the surgical approach. RESULTS: A solitary PA was depicted at preoperative scintigraphy in 135 of 141 patients (95.7%), two or more PA in 5 patients, and was negative in 6 patients (4.3%). In 27 patients, the PA was located deep in the paraesophageal/paratracheal space. One hundred and twenty-four patients (in 18 of them the PA was located deeply in the neck) underwent successful MIRS using the low 37 MBq (1 mCi) [(99m)Tc]MIBI dose protocol. Intraoperative quick parathyroid hormone (QPTH) assay demonstrated a fall >50% in respect to the baseline value in all patients, confirming successful parathyroidectomy. After a follow-up of 6 to 37 months (median 18 months), no case of persistent/recurrent PHPT was recorded. When comparing the parathyroid to background (P/B) ratio measured at planar and SPECT preoperative scintigraphy with that measured intraoperatively with the gamma probe, a significant linear correlation was found between the SPECT and intraoperative gamma probe measurements (r = 0.91; P <0.01) while no correlation was found with planar scintigraphic data. CONCLUSIONS: Our data suggest that the P/B ratio calculated by means of [(99m)Tc]MIBI SPECT is more accurate in predicting the intraoperative measurements with the intraoperative gamma probe. Thus, a preoperative [(99m)Tc]MIBI SPECT acquisition should be recommended for a better selection of PHPT patients to offer MIRS.

Inflammatory cytokine response and reduced heart rate variability in newborns with hypoxic-ischemic encephalopathy.

OBJECTIVE: To determine whether systemic inflammation-modulating cytokine expression is related to heart rate variability (HRV) in newborns with hypoxic-ischemic encephalopathy (HIE). STUDY DESIGN: The data from 30 newborns with HIE were analyzed. Cytokine levels (IL-2, IL-4, IL-6, IL-8, IL-10, IL-13, IL-1ß, TNF-α, IFN-λ) were measured either at 24 h of cooling (n=5), 72 h of cooling (n=4) or at both timepoints (n=21). The following HRV metrics were quantified in the time domain: alpha_S, alpha_L, root mean square (RMS) at short time scales (RMS_S), RMS at long time scales (RMS_L), while low-frequency power (LF) and high-frequency power (HF) were quantified in the frequency domain. The relationships between HRV metrics and cytokines were evaluated using mixed-models. RESULT: IL-6, IL-8, IL-10, and IL-13 levels were inversely related to selected HRV metrics. CONCLUSION: Inflammation-modulating cytokines may be important mediators in the autonomic dysfunction observed in newborns with HIE.

Patterns of Brain Injury in Newborns Treated with Extracorporeal Membrane Oxygenation.

BACKGROUND AND PURPOSE: Neonates treated with extracorporeal membrane oxygenation are at risk for brain injury and subsequent neurodevelopmental compromise. Advances in MR imaging and improved accessibility have led to the increased use of routine MR imaging after extracorporeal membrane oxygenation. Our objective was to describe the frequency and patterns of extracorporeal membrane oxygenation-related brain injury based on MR imaging findings in a large contemporary cohort of neonates treated with extracorporeal membrane oxygenation. MATERIALS AND METHODS: This was a retrospective study of neonatal patients treated with extracorporeal membrane oxygenation from 2005-2015 who underwent MR imaging before discharge. MR imaging and ultrasound studies were reviewed for location and type of parenchymal injury, ventricular abnormalities, and increased subarachnoid spaces. Parenchymal injury frequencies between patients treated with venoarterial and venovenous extracorporeal membrane oxygenation were compared by χ2 tests. RESULTS: Of 81 neonates studied, 46% demonstrated parenchymal injury; 6% showed infarction, mostly in vascular territories (5% anterior cerebral artery, 5% MCA, 1% posterior cerebral artery); and 20% had hemorrhagic lesions. The highest frequency of injury occurred in the frontal (right, 24%; left, 25%) and temporoparietal (right, 14%; left, 19%) white matter. Sonography had low sensitivity for these lesions. Other MR imaging findings included volume loss (35%), increased subarachnoid spaces (44%), and ventriculomegaly (17% mild, 5% moderate, 1% severe). There were more parenchymal injuries in neonates treated with venoarterial (49%) versus venovenous extracorporeal membrane oxygenation (29%, P = .13), but the pattern of injury was consistent between both modes. CONCLUSIONS: MR imaging identifies brain injury in nearly half of neonates after treatment with extracorporeal membrane oxygenation. The frontal and temporoparietal white matter are most commonly affected, without statistically significant laterality. This pattern of injury is similar between venovenous and venoarterial extracorporeal membrane oxygenation, though the frequency of injury may be higher after venoarterial extracorporeal membrane oxygenation.

Cerebral modulation of the autonomic nervous system in term infants.

OBJECTIVE: Central topography of autonomic nervous system (ANS) function has yet to be fully deciphered. In adults it has been shown to lateralize sympathetic and parasympathetic influence predominantly to the right and left cerebral hemispheres, respectively. We examined functional topography of central ANS in newborn subjects utilizing spectral analysis of heart rate variability (HRV), an established measure of ANS function. STUDY DESIGN: We studied newborns with hypoxic-ischemic encephalopathy participating in a prospective study undergoing a therapeutic hypothermia protocol.We included subjects with continuous heart rate data over the first 3 h of normothermia (post rewarming) and brain magnetic resonance imaging, which was reviewed and scored according to a 4 region scheme. HRV was evaluated by spectral analysis in the low-frequency (0.05 to 0.25 Hz) and high-frequency (0.3 to 1 Hz) ranges. The relationship between injured brain regions and HRV was studied using multiple regressions. RESULTS: Forty eight newborns were included. When examined in isolation, right hemisphere injury had a significant negative effect on HRV (-0.088; 95% CI: -0.225,-0.008). The combination of posterior fossa region injury with right hemispheric injury or left hemispheric injury demonstrated significant positive (0.299; 95% CI: 0.065, 0.518) and negative (-0.475; 95% CI: -0.852, -0.128) influences on HRV, respectively. The association between brain injury location and HRV in the high-frequency range did not reach significance. CONCLUSION: Our data support the notion that lateralized cerebral modulation of the ANS, specifically of its sympathetic component, is present in the term newborn, and suggest complex modulation of these tracts by components of the posterior fossa.

Impact of prenatal diagnosis of fetus-in-fetu.

Fetus in fetu (FIF) is an extremely rare condition (1/500,000 live births) in which a fetiform structure is incorporated into the body of its twin. FIF can be a diagnostic dilemma due to its similarity to a teratoma, but identification of FIF is important for subsequent medical and surgical management. We compare two cases of fetal masses diagnosed on prenatal imaging that were later identified as FIF through further radiological, surgical, and pathologic evaluation. We use these cases to illustrate key pre- and postnatal features of FIF and highlight the benefits of prenatal detection and follow-up for postnatal management.

Rigorous time-domain analysis of dielectric optical waveguides using Hertzian potentials formulation.

This work analyzes a new simulation approach to the evaluation of the time-domain electromagnetic (EM) field by reducing the number of equations to solve. Scalar Helmholtz-equations are utilized in order to determine the electric and magnetic Hertzian-potentials that yield the EM field. The method is applied to the example of optical waveguide arrays by considering the field-perturbation effect due to high dielectric contrast and dielectric discontinuities. The rigorous Hertzian potentials formulation is extended to bi-dimensional structures.

Can delivery room management impact the length of hospital stay in premature infants?

OBJECTIVES: To evaluate the impact of initiating early nasal continuous positive airway pressure (ENCPAP) on the length of hospital stay (LOS) for the very low birth weight (VLBW) infants. STUDY DESIGN: LOS at the George Washington University Hospital (GW) after the institution of ENCPAP policy was compared to benchmark values using two-tail t-tests. The incidence of neonatal morbidity was calculated using Bonferroni corrected 95% confidence interval as compared to benchmark rates (alpha=0.001). Comparisons were repeated after stratification of the population into four birth weight subcategories: group A (GrpA) (501 to 750 g), GrpB (751 to 1000 g), GrpC (1001 to 1250 g) and GrpD (1251 to 1500 g). RESULTS: We studied 228 consecutive VLBW infants (birth weight: 995+/-294 g and gestational age: 27.7+/-2.7 weeks). Compared to benchmark values, the GW experience was associated with a significant reduction of 5.1 days in LOS (55.9+/-25.2 vs 61+/-32 days; P=0.04). The decrease in LOS was consistent in all subgroups, but was most noticeable in infants of the smallest weight subcategory (LOS in GrpA=86+/-21 vs 104+/-32, P=0.004; in GrpB=69.9+/-16.7 vs 79+/-27, P=0.018; in GrpC=48.2+/-13 vs 56+/-22, P<0.001 and in GrpD=31.7+/-12.5 vs 40+/-19, P=0.003). In the overall population, a lower incidence of chronic lung disease (CLD) (17.8 vs 29%, P<0.001) was also noted. There were no differences in mortality rates (9 vs 14%), or the incidence of necrotizing enterocolitis (NEC) (8 vs 6%) or intraventricular hemorrhage (6.2 vs 9%) between GW and the established benchmark rates. CONCLUSION: ENCPAP may reduce LOS in VLBW infants in our study population. This relatively shorter LOS was associated with a lower incidence of CLD, which may be a contributing factor.