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BACKGROUND Contrast bolus variation during contrast-enhanced magnetic resonance angiography (CE-MRA) acquisition may lead to vessel blurring. PURPOSE To combine knowledge of how contrast signal intensity (SI) evolves for different injection strategies with anatomically familiar parametric computer models to measure and visually assess the effects of a wide range of variables on modeled CE-MRA, and in doing so develop contrast rate injection guidelines. STUDY TYPE Computer modeling. PHANTOM Digital three-dimensional phantom consisting of orthogonal "aorta," 7 mm diameter "renal arteries" (with 57% and 86% diameter stenoses), and 7 mm diameter "superior mesenteric artery" (with 57% diameter stenosis). FIELD STRENGTH/SEQUENCE One millimeter in-plane resolution arterial CE-MRA imaging at 3 T. ASSESSMENT "Background" (time invariant) and "vascular" (time varying) components of the phantom were each Fourier transformed into the spatial frequency domain, the latter modulated by the SI evolution of a contrast bolus of varying "plateau" lengths and "tail" heights. Data are presented as surface plots of stenosis measurement error and blurring vs. a reference-standard injection. STATISTICAL TESTS Descriptive. RESULTS Shorter plateau lengths and lower tail heights resulted in increased measured stenosis error and blurring vs. the reference standard. Under a 44-second acquisition, full width half maximum stenosis error of the 86% stenosis with 25% plateau length and 25% tail height is 24% as compared to that from the reference standard. As plateau length and tail height approach 100%, stenosis error and blurring approach a floor defined by the MR acquisition's limitations. DATA CONCLUSION We propose that to achieve minimal degradation with CE-MRA, one can create a contrast bolus with either 60% plateau and 50% tail height or 80% plateau with any tail. These considerations may well prove to be of practical importance, possibly via manipulating the tail by means of multiphasic contrast injections. LEVEL OF EVIDENCE 3 TECHNICAL EFFICACY: Stage 1.

Perovskite-based photovoltaic materials have been attracting attention for their strikingly improved performance at converting sunlight into electricity. The beneficial and unique optoelectronic characteristics of perovskite structures enable researchers to achieve an incredibly remarkable power conversion efficiency. Flexible hybrid perovskite photovoltaics promise emerging applications in a myriad of optoelectronic and wearable/portable device applications owing to their inherent intriguing physicochemical and photophysical properties which enabled researchers to take forward advanced research in this growing field. Flexible perovskite photovoltaics have attracted significant attention owing to their fascinating material properties with combined merits of high efficiency, light-weight, flexibility, semi-transparency, compatibility towards roll-to-roll printing, and large-area mass-scale production. Flexible perovskite-based solar cells comprise of 4 key components that include a flexible substrate, semi-transparent bottom contact electrode, perovskite (light absorber layer) and charge transport (electron/hole) layers and top (usually metal) electrode. Among these components, interfacial layers and contact electrodes play a pivotal role in influencing the overall photovoltaic performance. In this comprehensive review article, we focus on the current developments and latest progress achieved in perovskite photovoltaics concerning the charge selective transport layers/electrodes toward the fabrication of highly stable, efficient flexible devices. As a concluding remark, we briefly summarize the highlights of the review article and make recommendations for future outlook and investigation with perspectives on the perovskite-based optoelectronic functional devices that can be potentially utilized in smart wearable and portable devices.

Evidence mounts that the steady-state cellular water efflux (unidirectional) first-order rate constant (k

We introduce a new

The development of perovskite solar cells (PSCs) as an efficient and cost-effective alternative to traditional approaches to solar energy transduction has received much recent attention, and there has been considerable progress made with reported power conversion efficiencies now surpassing 25%. This development is encouraging and is a result of intensive research on device design, factors affecting long-term stability of PSCs, and systematic material development in which electron transport layer (ETL) materials play a crucial role to afford high-performance PSC devices. ETL materials, including (6-(1,10-phenanthrolin-3-yl)naphthalen-2-yl)diphenylphosphine oxide (Phen-NaDPO), and n-type materials based on the naphthalene diimide (NDI) structure, appear to be amongst the most promising materials to date. This article provides an up-to-date review on organic n-type ETL materials, both polymeric and small molecules, based on NDI format, detailing reports of structures with key relevant parameters, such as the efficiency and stability of PSCs. The review is written from a perspective of organic chemistry and we believe this will provide fundamental advice on the future design of new ETL materials based on NDIs that will afford more efficient and stable PSCs.

In this paper, an analysis of three-dimensional transient thermal transfer is presented to evaluate the performance of a photovoltaic thermal module with an optimize structural design, incorporating direct use of an aluminum collector as the substrate. The effect of cross-sectional geometries and ratios of size and spacing was considered to optimize the performance of a photovoltaic-thermal (PVT) module. The temperature, velocity and pressure distributions were demonstrated in a steady state model using a finite element method. Simulation results indicated the temperature of the PVT module was increased by the solar irradiation incident with the panel, yet overall decreased by an increased flow velocity. In this study, we examine seven types of media used as the medium to cool the PVT module, where water was preferred, due to its higher specific heat capacity. Further, for multiple interconnected PVT modules, connecting method in parallel and series resulted in pressure drop for the PVT module. In addition, the simulations were compared to experimental data providing validation of the estimated operating temperature in agreement with simulation results, and the outcomes will provide an indication for preferred assembly of PVT modules for application in building integration and future product design.

Genetic kidney disease is increasingly identified as a cause of chronic kidney disease (CKD) in patients who have previously had no known etiology.1 Following advances in genetic sequencing and understanding, more than 500 monogenic etiologies have been identified as causes of CKD, and there are likely many additional genes yet to be identified.1 Kidney transplantation is currently the most effective form of kidney replacement therapy, and living kidney transplants continue to have the greatest short- and long-term patient and allograft survival.2 However, living-related kidney transplantation in patients with an unknown cause of end-stage kidney disease (ESKD) is clinically and ethically complex, as a donating family member may also have undiagnosed genetic kidney disease in a presymptomatic state. By removing a kidney, the time to ESKD for the donor is potentially shortened.

Efficiencies of perovskite solar cells (PSCs) have risen unprecedentedly from 3.8% to 25.2% in just over a decade as the light absorber material has evolved from the original methylammonium (MA)- to formamidinium (FA)-dominated perovskite. While FA lead iodide (FAPbI3) has a lower bandgap and, therefore, a higher theoretical efficiency limit, it is less phase stable, although this can overcome by incorporating cesium (Cs), MA, bromide (Br), or a combination of these. Cs being a nonvolatile component remains in the perovskite film and therefore it is important to understand the effect of the amount of Cs on film properties and associated PSC performance and stability. Future research opportunities for Cs-containing PSCs including large-area demonstrations are also discussed in this review.

Background. Cardiovascular disease is a major cause of morbidity and mortality in kidney transplant recipients. Trial evidence to improve cardiovascular outcomes is limited by inconsistent reporting of outcomes, which may also lack patient-relevance. This study aimed to assess the range and consistency of cardiovascular outcomes reported by contemporary trials in kidney transplant recipients. Methods. A systematic review of all randomized controlled trials involving adult kidney transplant recipients that reported at least 1 cardiovascular outcome from January 2012 to December 2019 was performed, including Embase, MEDLINE, Cochrane, and ClinicalTrials.gov electronic databases. Trial characteristics were extracted and all levels of specification of the cardiovascular outcome measures reported were analyzed (the measure definition, metric‚ and method of aggregation). Measures assessing a similar aspect of cardiovascular disease were categorized into outcomes. Results. From 93 eligible trials involving 27 609 participants, 490 outcome measures were identified. The outcome measures were grouped into 38 outcomes. A cardiovascular composite was the most common outcome reported (40 trials, 43%) followed by cardiovascular mortality (42%) and acute coronary syndrome (31%). Cardiovascular composite was also the most heterogeneous outcome with 77 measures reported followed by cardiovascular mortality (n = 58) and inflammatory biomarkers (n = 51). The most common cardiovascular composite outcome components reported were major cardiovascular events (18 trials), stroke unspecified (11 trials), and myocardial infarction unspecified (10 trials). Conclusions. There is substantial heterogeneity in cardiovascular outcome reporting in kidney transplant trials.

Perovskite solar cells (PSCs) have achieved unprecedented progress in terms of enhancement of power conversion efficiency (PCE). Nevertheless, device stability is still an obstacle to the commercialization of this emerging photovoltaic technology. Though strategies such as compositional management and ligand engineering have been reported to tackle this critical issue, these methods often have drawbacks such as compromised device performance. Herein, we propose an approach combining material dimensionality control and interfacial passivation by a post-device treatment via triethylenetetramine (TETA) vapor to enhance both efficiency and stability of Cs0.05FA0.79MA0.16PbI2.5Br0.5-based PSCs. Results of X-ray diffraction and scanning electron microscopy show the formation of low-dimensional perovskites at the interface between the perovskite film and the hole transporting layer after the TETA vapor treatment. Measurements of the energy level alignment and electrochemical properties by ultraviolet photoelectron spectroscopy and impedance spectra confirm the reduced density of trap states and improved interfacial charge transport. Consequently, TETA-based treatment significantly enhances both efficiency (from 17.07 to 18.03%) and stability (PCE retention from 73.4 to 88.9%) of the PSCs under >65% relative humidity for 1000 h compared to the controlled device without TETA treatment. Furthermore, the TETA vapor also shows an advantageous effect of dramatically improving the performance of PSC devices, which initially had poor performance (from 6.8 to 10.5%) through surface defect passivation.

Defects at discontinuities of the perovskite lattice limit the performance of the perovskite solar cell (PSC). Lead iodide (PbI2) and pyridine have been shown to passivate these defects. We treat methylammonium lead iodide (MAPbI3) films with pyridine solutions to investigate the effects of the two passivators. By comparing confocal fluorescence microscopy (CFM) images at 405 nm excitation and then at 559 nm excitation we demonstrate the pyridine treatment passivates and forms PbI2 crystallites which cause additional passivation.

Radiation is energy travelling through space. Sunlight radiation such as ultraviolet (UV) radiation are higher-energy radiation which are used in medicine and energy industry such as dye sensitized solar cells (DSSCs). We recently designed new Ru-complexes through novel ligands based on a recently synthesised high performance dye, i.e. [(η6-p-cymene)Ru(4,4′,5,5′-H4tcbpy)Cl]Cl [1] (A as L1-Ru-L2) for applications in DSSCs. Two electron rich top-ligands, η6-N, N, N′, N′-tetramethyl-p-phenylenediamine (new dye D) and η6- 1,4 di[(dimethylamino)ethyl] benzene (new dye E) outperform other ligands for the new high performance Ru-complexes. Our time dependent density functional theory (TD-DFT) using the CAM-B3LYP/6-311G+(d)/LANL2DZ functional and basis-set model reveals the apparent enhancement of the major UV–vis bands of metal to ligand charge transfer (MLCT) in the new dyes. The major UV–vis bands of the new dyes D and E are red shifted 35 nm and 78 nm, respectively, from the MLCT band of the reference dye A centred at 433 nm. We further discovered that the electron rich top-ligands (L1) are responsible to lift a cluster of occupied outer valence orbitals such as HOMO, HOMO-1 and HOMO-2 in the new D and E complexes, while the virtual orbitals which concentrate on the lower ligand L2 (4,4′,5,5′ H4 tcbpy) remain almost unchanged. The top-ligand L1 enhances the MLCT transition of the new dyes D and E through the dominant 7dz2 electrons of the transition metal Ru in their HOMOs. The present study provides the rational of ligand control for metal complexes in broader applications such as electron transfer and electronics.

Device instability has become an obstacle for the industrial application of organic–inorganic metal halide perovskite solar cells that has already demonstrated over 23% laboratory power conversion efficiency (PCE). It has been discovered that the sliding of A-site cations in the perovskite compound through and out of the three-dimensional [PbI6]4– crystal frame is one of the main reasons that are responsible for decomposition of the perovskite compound. Herein, we report an effective method to enhance the stability of the FA0.79MA0.16Cs0.05PbI2.5Br0.5 perovskite film through the incorporation of n-propylammonium iodide (PAI). Both density functional theory calculation and the X-ray diffraction patterns have confirmed the formation of two-dimensional (PA)2PbI4 with the Ruddlesden–Popper perovskite as a result of the reaction between PAI and PbI2 in the perovskite film. X-ray photoelectron spectroscopy reveals less −COOH (carboxyl) groups on the surface of the perovskite film containing (PA)2PbI4, which indicates the suppressed penetration of oxygen and moisture into the perovskite material. This is further confirmed by the surface water wettability test of the (PA)2PbI4 film that exhibits excellent hydrophobic property with over 110° contact angle. Ultraviolet photoelectron spectroscopy demonstrates the introduction of PAI additives that resulted in the upshift of the conduction band minimum of the perovskite by 160 meV, leading to a more favorable energy alignment with an adjacent electron transporting material. As a consequence, enhanced 17.23% PCE with suppressed hysteresis was obtained with the 5% PAI additive (molar ratio) in perovskite solar cells that retained nearly 50% of the initial efficiency after 2000 h in air without encapsulation under 45% average relative humidity.

Intracellular protein homeostasis is maintained by a network of chaperones that function to fold proteins into their native conformation. The eukaryotic TRiC chaperonin (TCP1-ring complex, also called CCT for cytosolic chaperonin containing TCP1) facilitates folding of a subset of proteins with folding constraints such as complex topologies. To better understand the mechanism of TRiC folding, we investigated the biogenesis of an obligate TRiC substrate, the reovirus σ3 capsid protein. We discovered that the σ3 protein interacts with a network of chaperones, including TRiC and prefoldin. Using a combination of cryoelectron microscopy, cross-linking mass spectrometry, and biochemical approaches, we establish functions for TRiC and prefoldin in folding σ3 and promoting its assembly into higher-order oligomers. These studies illuminate the molecular dynamics of σ3 folding and establish a biological function for TRiC in virus assembly. In addition, our findings provide structural and functional insight into the mechanism by which TRiC and prefoldin participate in the assembly of protein complexes.

Transition metal complexes offer cost-effective alternatives as hole-transport materials (HTMs) in perovskite solar cells. However, the devices suffer from low performance. We boost the power conversion efficiency of devices with transition metal complex HTMs from 2% to above 10% through energy level tuning. We further demonstrate the excellent photostability of the device based on the additive-free HTM.

Purpose The purpose of the study was to increase the proportion of youth living with HIV (YLWH) aged ≥11 years who undergo developmentally appropriate disclosure about their HIV status. Methods A quality improvement project was initiated at an urban pediatric HIV clinic between July 2018 and March 2020. The primary outcome measure was the proportion of YLWH aged ≥11 years who were disclosed to about their HIV status. The proportion of undisclosed YLWH who had documented nondisclosure status was also assessed as a process measure. Plan-Do-Study-Act (PDSA) cycles for change included monthly clinic staff check-ins to discuss new disclosures, quarterly team meetings to discuss strategies to improve disclosure, and modifying a clinic note template to prompt providers to document disclosure status. Annotated run charts were used to analyze the data. Results Before the first PDSA cycle, 26/46 (57%) of the target population of YLWH aged ≥11 years had their HIV status disclosed to them, and none of the undisclosed youth had disclosure status documented in their medical record. After 20 months and six PDSA cycles, the proportion of YLWH aged ≥11 years disclosed to about their HIV status increased to 80% and the proportion of undisclosed YLWH with documentation of their disclosure status increased to 100%. Conclusions Several interventions integrated throughout the pediatric HIV care process were associated with an increase in the proportion of YLWH with developmentally appropriate HIV disclosure and documentation of disclosure status, an important psychosocial aspect of care in these individuals.

Defects at discontinuities of the perovskite lattice limit the performance of the perovskite solar cell (PSC). Lead iodide (PbI

Background:Peritoneal dialysis (PD)-associated peritonitis carries significant morbidity, mortality, and is a leading cause of PD technique failure. This study aimed to assess the scope and variability of PD-associated peritonitis reported in randomized trials and observational studies.Methods:Cochrane Controlled Register of Trials, MEDLINE, and Embase were searched from 2007 to June 2018 for randomized trials and observational studies in adult and pediatric patients on PD that reported PD-associated peritonitis as a primary outcome or as a part of composite primary outcome. We assessed the peritonitis definitions used, characteristics of peritonitis, and outcome reporting and analysis.Results:Seventy-seven studies were included, three were randomized trials. Thirty-eight (49%) of the included studies were registry-based observational studies. Twenty-nine percent ( n = 22) of the studies did not specify how PD-associated peritonitis was defined. Among those providing a definition of peritonitis, three components were reported: effluent cell count ( n = 42, 54%), clinical features consistent with peritonitis (e.g. abdominal pain and/or cloudy dialysis effluent) ( n = 35, 45%), and positive effluent culture ( n = 19, 25%). Of those components, 1 was required to make the diagnosis in 6 studies (8%), 2 out of 2 were required in 22 studies (29%), 2 out of 3 in 11 studies (14%), and 3 out of 3 in 4 studies (5%). Peritonitis characteristics and outcomes reported across studies included culture-negative peritonitis ( n = 47, 61%), refractory peritonitis ( n = 42, 55%), repeat peritonitis ( n = 9, 12%), relapsing peritonitis ( n = 5, 7%), concomitant exit site ( n = 16, 21%), and tunnel infections ( n = 8, 10%). Peritonitis-related hospitalization was reported in 38% of the studies ( n = 29), and peritonitis-related mortality was variably defined and reported in 55% of the studies ( n = 42). Peritonitis rate was most frequently reported as episodes per patient year ( n = 40, 52%).Conclusion:Large variability exists in the definitions, methods of reporting, and analysis of PD-associated peritonitis across trials and observational studies. Standardizing definitions for reporting of peritonitis and associated outcomes will better enable assessment of the comparative effect of interventions on peritonitis. This will facilitate continuous quality improvement measures through reliable benchmarking of this patient-important outcome across centers and countries.

Ultra-small superparamagnetic iron oxide (USPIO) nanoparticles provide a safer alternative to gadolinium-based contrast agents (GBCAs) in T1-weighted MR imaging. MRI contrast behavior of USPIOs depends on their magnetic properties, which in turn depend on their physicochemical composition. Identifying and tailoring USPIO structural characteristics that influence proton relaxation in MRI is crucial to developing effective gadolinium-free T1 contrast agents. Here, we present a systematic empirical evaluation of the relationship between USPIO size and MRI relaxivity (r1 and r2 values). Monodisperse USPIO cores, with precisely controlled core diameter (dC ) were synthesized via the thermal decomposition of iron(III)-oleate precursor. USPIOs with dC = 6.34, 7.58, 8.58, and 9.50nm, were dispersed in aqueous phase via ligand exchange with silane or dopamine-modified polyethylene glycol (PEG) polymers. Relaxivity characterization in a 1.5 T clinical MRI scanner showed the r2 /r1 ratio increased linearly with USPIO core diameter (R2 = 0.95), but varied little with both hydrodynamic diameter (dH ) and PEG molecular weight. One sample, DOPA-6-20 (6.34nm USPIO cores coated with 20 kDa dopamine-modified PEG), provided the lowest r2 /r1 value (3.44) and thus promise as a potential T1 contrast agent. In a preliminary study, we evaluated DOPA-6-20 for in vivo angiography imaging in a mouse with a 7 T scanner and observed strong T1-weighted enhancement of the mouse blood pool. Key anatomical features in the vascular network were visible even 5 min after intravenous administration. Using empirical data, we have presented the basis of a structure-property relationship that can help develop optimized USPIO-based T1 contrast agents. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A:2440-2447, 2018.

Histomorphometry of endomyocardial biopsies is one component of arrhythmogenic right ventricular cardiomyopathy (ARVC) diagnosis, although there is a need for stricter diagnostic criteria for this disease in pediatrics. The clinical utility of biopsy analysis as a component of ARVC diagnosis was evaluated in pediatric patients. Histomorphometric analysis of fibrofatty infiltrate was completed on pediatric right ventricular endomyocardial biopsy samples. Myocardial replacement by fat and fibrosis was quantified. ARVC diagnosis was established using the 2010 ARVC Task Force criteria, with the biopsy measures compared across various ARVC diagnoses (definite, borderline, possible, or no ARVC). Receiver-operating characteristic (ROC) curve analysis was also completed using biopsy measures. The greatest proportion of fat, fibrosis, and myocardial replacement was in the definite ARVC cohort, and was significantly larger than for the other diagnosis cohorts. ROC curve analysis (with the biopsy analysis removed from the diagnostic classification) produced cutoff values of 15 and 25% myocardial replacement, which is lower than current adult diagnosis criteria. We propose modifications in pediatric major and minor biopsy diagnosis criteria to allow for improved sensitivity. This study suggests that biopsy analysis in children is most significant for subjects with a more severe disease presentation.

In printable mesoscopic perovskite solar cells (PSCs), carbon electrodes play a significant role in charge extraction and transport, influencing the overall device performance. The work function and electrical conductivity of the carbon electrodes mainly affect the open-circuit voltage (VOC) and series resistance (Rs) of the device. In this paper, we propose a hybrid carbon electrode based on a high-temperature mesoporous carbon (m-C) layer and a low-temperature highly conductive carbon (c-C) layer. The m-C layer has a high work function and large surface area and is mainly responsible for charge extraction. The c-C layer has a high conductivity and is responsible for charge transport. The work function of the m-C layer was tuned by adding different amounts of NiO, and at the same time, the conductivities of the hybrid carbon electrodes were maintained by the c-C layer. It was supposed that the increase of the work function of the carbon electrode can enhance the VOC of printable mesoscopic PSCs. Here, we...

Organic–inorganic hybrid lead halide perovskite solar cells have demonstrated competitive power conversion efficiency over 22%; nevertheless, critical issues such as unsatisfactory device stability, serious current–voltage hysteresis, and formation of photo nonactive perovskite phases are obstacles for commercialization of this photovoltaics technology. Herein we report a facial yet effective method to hinder formation of photoinactive δ-FAPbI3 and hysteresis behavior in planar heterojunction perovskite solar cells based on Kx(MA0.17FA0.83)1–xPbI2.5Br0.5 (0≤ x ≤ 0.1) through incorporation of potassium ions (K+). X-ray diffraction patterns demonstrate formation of photoinactive δ-FAPbI3 was almost completely suppressed after K+ incorporation. Density functional theory calculation shows K+ prefers to enter the interstitial sites of perovskite lattice, leading to chemical environmental change in the crystal structure. Ultrafast transient absorption spectroscopy has revealed that K+ incorporation leads to enh...

A smooth and compact light absorption perovskite layer is a highly desirable prerequisite for efficient planar perovskite solar cells. However, the rapid reaction between CH3NH3I methylammonium iodide (MAI) and PbI2 often leads to an inconsistent CH3NH3PbI3 crystal nucleation and growth rate along the film depth during the two-step sequential deposition process. Herein, a facile solvent additive strategy is reported to retard the crystallization kinetics of perovskite formation and accelerate the MAI diffusion across the PbI2 layer. It was found that the ultrasmooth perovskite thin film with narrow crystallite size variation can be achieved by introducing favorable solvent additives into the MAI solution. The effects of dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, chlorobenzene, and diethyl ether additives on the morphological properties and cross-sectional crystallite size distribution were investigated using atomic force microscopy, X-ray diffraction, and scanning electron microscopy. Further...

We obtain a novel kind of highly-conductive, low-temperature and perovskite-compatible carbon paste treated with the functional additives of titanium (IV) isopropoxide and acetic acid. The functional additives in the carbon paste can in si-tu generate newly complex polymeric Ti-O-Ti species acting as binder and plasticizer. It helps the electrical conductivity of carbon film increase to 1.13 × 104 S m−1, which corresponds to a sheet resistance of 4 Ω □−1 for a typical 20 μm film, superior to the transparent FTO/ITO electrode (15 Ω □−1). Then the carbon film is applied as the low-temperature carbon electrode into fully printable mesoscopic perovskite solar cells and a champion efficiency of 14.04% is achieved. Meanwhile, the series resistance of device based on low-temperature carbon electrode can be reduced from 21 to 13 Ω cm2, compared to device based on high temperature carbon electrode only. This low-temperature, low cost, highly-conductive carbon film shows promising application in the future module design of fully printable mesoscopic perovskite solar cells.

Background:Pseudomonas aeruginosa uncommonly causes illness in neonatal intensive care units (NICU). A cluster of 4 infections was appreciated over 6 weeks in our inborn–delivery NICU, prompting an investigation. Methods: Upon recognition of a cluster of infections, we retrospectively audited all cultures positive for P. aeruginosa from all sites (sterile and nonsterile) over the prior year in the index NICU (NICU 1, inborn) and for comparison in the adjacent NICU (NICU 2, larger, outborn–surgical). We performed multilocus sequence testing (MLST) of available clinical isolates to identify clonality. We initiated quarterly prospective surveillance of P. aeruginosa colonization of infants through nares, perirectal swabs, and tracheal aspirates of intubated infants or oropharyngeal swabs of nonintubated infants. We also swabbed incubators, ventilatory equipment, and sinks for selective P. aeruginosa culturing. Results: We identified 7 invasive P. aeruginosa infections in the inborn NICU (5 bloodstream and 2 pneumonia) over an 11-month period (Figure 1). Over the same period, there were no P. aeruginosa bloodstream infections in the adjacent NICU. Affected neonates were high risk: gestational age ranged from 22 weeks and 4 days to 26 weeks and 3 days; day of life at infection ranged from 6 to 37; 6 infants were on a jet ventilator; and all infants were receiving enteral nutrition (6 of 7 with donor human milk and 7 of 7 with expressed mother’s milk). Two infants died from their infection, and 5 infants survived to hospital discharge. All 7 isolates were pansusceptible to routine antimicrobials. MLST of the first 4 available isolates demonstrated 4 different sequence types; however, the first 2 were from the same clonal complex, indicating relatedness (Figure 1). For environmental samples, 8 obtained 8 cultures (swabs) of incubators and ventilatory equipment, and 24 cultures of faucets and drains of all sinks. Only sink cultures were positive, yielding 3 isolates identified as P. aeruginosa and 4 isolates identified as P. aeruginosa–like. Whole-genome sequencing (WGS) is underway to identify relatedness to the clinical isolates. We initiated quarterly infant surveillance by swab culture for P. aeruginosa nasal colonization then escalated to perirectal and oropharyngeal swab or tracheal aspirate cultures (intubated infants) in subsequent quarters. We did not detect any infants colonized with P. aeruginosa. Conclusions: We identified a cluster of P. aeruginosa in high-risk neonates with no point source. Molecular typing indicated a multiclonal cluster. This finding poses a management dilemma. A colonized water system is suspected and WGS of environmental samples is underway.Funding: NoDisclosures: None

Introduction: Salmonella causes 0.45% of osteomyelitis cases(1) and is uncommon without predisposing conditions.(2) Vertebral infection with Salmonella is rare.(1,3) We report a previously healthy adolescent with Salmonella oranienburg cervical osteomyelitis. Case Description: A 15-year-old male presented with several years of intermittent neck pain, which worsened over four days. Associated symptoms included subjective fevers, one day of vomiting, and near-syncope the day prior to presentation. Symptoms were preceded by a febrile respiratory illness two weeks before. He denied sore throat, abdominal pain, diarrhea, weakness, or numbness. Besides playing soccer, he had no trauma. He traveled to Mexico two months prior. His mother recently returned from Malaysia. On examination, his temperature was 38.3 degrees …

Black phosphorus (BP) has emerged as an exciting 2D material for optics, photonics, and electronics. However, there are few studies on BP in terms of modulation and enhancement of their electronic and optical properties and their concurrent reactivity and hence reduction after exposure to the ambient environment. To resolve such challenges, creating inorganic–organic hybrid materials is a suitable approach that offers significant opportunities to enhance the utility of BP by combining them with an organic material which has a complementary set of properties. Herein, a hybrid‐layered BP material coupled with a low bandgap donor–acceptor organic semiconducting polymer, selenophene‐flanked diketopyrrolopyrrole with thienyl‐vinylene‐thienyl (PDPPSe–TVT) is reported, to broaden the optical absorption and tune the ambipolar field effect transistor characteristics. A highly sensitive, nongated broadband photodetection capability of the hybrid device with a detection range from UV–vis to near‐IR (280–1050 nm) and responsivities of up to 4.22 × 103 A W−1 in ambient conditions. In addition to improved photodetection, simultaneous enhancement in both hole (71%) and electron (91%) mobilities is achieved while protecting the sensitive BP material from rapid environmental degradation. The findings therefore report a breakthrough in enhancing the utility of BP as a light‐active material for versatile photonics and electronics applications without operating in an inert environment.

Summary The power conversion efficiency (PCE) of metal halide perovskite solar cells (PSCs) has improved dramatically from 3.8% to 25.5% in only a decade. Gas quenching is a desirable method for fabricating high-efficiency cells as it does not consume antisolvents and is compatible with large-area deposition methods such as doctor blading and slot-die coating. To further improve PCEs for gas-quenched PSCs, here, we develop complementary bulk and surface passivation strategies by incorporating potassium iodide (KI) in the perovskite precursor and applying n-hexylammonium bromide (HABr) to the perovskite surface. We show that (1) KI induces a spatial-compositional change, improving grain boundary properties; (2) KI and HABr reduce traps, especially at levels close to the mid-gap; and (3) HABr greatly improves the built-in potential of the device, thereby improving voltage output. The champion device achieves a steady-state PCE of 23.6% with a VOC of 1.23V, which is, to the best of our knowledge, the highest for PSC by gas quenching to date.

BACKGROUNDInfants and young children are frequently colonized with C. difficile but rarely have symptomatic disease. However, C. difficile testing remains prevalent in this age group.OBJECTIVETo design a computerized provider order entry (CPOE) alert to decrease testing for C. difficile in young children and infants.DESIGNAn interventional age-targeted before-after trial with comparison groupSETTINGMonroe Carell Jr. Children’s Hospital at Vanderbilt University, Nashville, Tennessee.PATIENTSAll children seen in the inpatient or emergency room settings from July 2012 through July 2013 (pre-CPOE alert) and September 2013 through September 2014 (post-CPOE alert)INTERVENTIONIn August of 2013, we implemented a CPOE alert advising against testing in infants and young children based on the American Academy of Pediatrics recommendations with an optional override. We further offered healthcare providers educational seminars regarding recommended C. difficile testing.RESULTSThe average monthly testing rate significantly decreased after the CPOE alert for children 0–11 months old (11.5 pre-alert vs 0 post-alert per 10,000 patient days; PPP=.3) who were not targeted with a CPOE alert. There were no complications in those children who testing positive for C. difficile.CONCLUSIONSThe average monthly testing rate for C. difficile for children C. difficile.Infect Control Hosp Epidemiol 2017;38:542–546

Background Membranoproliferative glomerulonephritis (MPGN) is an uncommon cause of end stage kidney disease (ESKD) and the clinical outcomes of patients with MPGN who commence kidney replacement therapy have not been comprehensively studied. Methods All adult patients with ESKD due to glomerulonephritis commencing kidney replacement therapy in Australia and New Zealand from January 1, 1996 to December 31, 2016 were reviewed. Patients with ESKD due to MPGN were compared to patients with other forms of glomerulonephritis. Patient survival on dialysis and following kidney transplantation, kidney recovery on dialysis, time to transplantation, allograft survival, death-censored allograft survival and disease recurrence post-transplant were compared between the two groups using Kaplan Meier survival curves and Cox proportional hazards regression. Results Of 56,481 patients included, 456 (0.8%) had MPGN and 12,660 (22.4%) had another form of glomerulonephritis. Five-year patient survival on dialysis and following kidney transplantation were similar between patients with ESKD from MPGN and other forms of glomerulonephritis (Dialysis: 59% vs. 62% p = 0.61; Transplant: 93% vs. 93%, p = 0.49). Compared to patients with other forms of glomerulonephritis, patients with MPGN had significantly poorer 5-year allograft survival (70% vs. 81% respectively, p = 0.02) and death censored allograft survival (74% vs. 87%, respectively; p p p Conclusions Compared with other forms of glomerulonephritis, patients with MPGN experienced comparable rates of survival on dialysis and following kidney transplantation, but significantly higher rates of allograft loss due to disease recurrence.

Background Adolescents and young adults living with HIV (AYALWH) comprise a heterogeneous population but have a common need for successful transitioning to adult care. Many institutions have formal transitioning protocols but many obstacles to successful implementation exist. Aims The purpose of this project was to investigate, design, and implement a Transition Clinic for AYALWH with a goal of maximizing retention during the transition and addressing their comprehensive health care needs. Methods We initially conducted a literature review to identify best practices of engaging AYALWH to care and to identify gaps in health care needs. We then conducted several site visits to learn how other institutions prepared and engaged AYALWH for transition of care. We identified 15 AYALWH (Age 17-26) in our community who were experiencing difficulties in transitions to adult care and had unmet health care needs. Results We determined the barriers to care for AYALWH in our community are stigma, transportation, and insurance navigation. In August of 2018 we initiated the Adolescent and Young Adult Health Care Transition Clinic. The clinic is staffed by an Adolescent Physician, an HIV care physician, an Adolescent Social Worker, and an Adult Transition Nurse and is embedded within the General Adolescent Clinic. We have seen 11 clients for a total of 23 visits since inception. We have addressed contraceptive/sexual health needs, primary care needs, behavioral health, and transition preparedness by offering a multidisciplinary approach and focusing on Youth Friendly Services. Our team spends time discussing and addressing barriers to care at each visit. Conclusions A multidisciplinary clinic can engage and improve access to health care for AYALWH. The potential benefits of this approach include reduction in stigma, improved comprehensive care, and focused time to discuss transition to adult care for youth living with a chronic ailment. We have commenced individualizing transition preparedness for each client through an IRB approved transition survey. Future directions include assessing adherence to treatment through our transition program by measuring serial viral loads during successful transition.

Device instability has become an obstacle for the industrial application of organic-inorganic metal halide perovskite solar cells that has already demonstrated over 23% laboratory power conversion efficiency (PCE). It has been discovered that the sliding of A-site cations in the perovskite compound through and out of the three-dimensional [PbI

Nanostructured tin (IV) oxide (SnO2) is emerging as an ideal inorganic electron transport layer in n–i–p perovskite devices, due to superior electronic and low-temperature processing properties. However, significant differences in current–voltage performance and hysteresis phenomena arise as a result of the chosen fabrication technique. This indicates enormous scope to optimize the electron transport layer (ETL), however, to date the understanding of the origin of these phenomena is lacking. Reported here is a first comparison of two common SnO2 ETLs with contrasting performance and hysteresis phenomena, with an experimental strategy to combine the beneficial properties in a bilayer ETL architecture. In doing so, this is demonstrated to eliminate room-temperature hysteresis while simultaneously attaining impressive power conversion efficiency (PCE) greater than 20%. This approach highlights a new way to design custom ETLs using functional thin-film coatings of nanomaterials with optimized characteristics for stable, efficient, perovskite solar cells.

BACKGROUND Gadolinium concentration variation during acquisition of contrast-enhanced MR angiography (CE-MRA) may lead to artifacts. PURPOSE To compare signal intensity (SI) profiles of four different contrast agent injection strategies during CE-MRA with the goal of minimizing SI variation during acquisition. STUDY TYPE Prospective. SUBJECTS Forty subjects randomized to receive one of four injection profiles of gadobenate dimeglumine (0.1 mmol/kg), either undiluted (0.5 M) or diluted to 40 ml total volume. Tested profiles: 1) nondiluted single-phase ("standard" NS; 1.6 ml/s), 2) diluted single-phase (DS; 1.6 ml/s), 3) diluted biphasic (DB; 9 ml @ 3.3 ml/s, 29 ml @ 1.4 ml/s), 4) patient-tailored protocol using linear prediction (DT). FIELD STRENGTH/SEQUENCE Time-resolved SI measured at 3T with spoiled gradient echo sequences having analogous parameters to those of CE-MRA. ASSESSMENT Plateau arrival time, rise time, duration, peak and tail SI, plateau quality (sum of squared residuals; SSR), average SI for each injection type derived were used. STATISTICAL TEST Two-tailed t-test. RESULTS Peak SI, arrival, and rise times were not significantly different between groups, excepting peak SI DB slightly > DS (P = 0.042). Duration of NS vs. the diluted groups was significantly shorter (all P < 0.0001), and DS duration was significantly shorter than that of DT and DB (NS 11.4 ± 3.5 vs. DS 22.9 ± 4.3, DB 25.4 ± 2.3, DT 28.3 ± 4.1 sec). Quality (SSR) of the 20-second plateau was significantly better for DS, DB, DT as compared with NS (all P < 0.001). DATA CONCLUSION Three different strategies to power-inject diluted gadobenate dimeglumine targeting a 20-second plateau produced SI profiles with longer duration, more consistent plateau, and no significant loss in peak SI. Such injection profiles may provide more uniform SI during CE-MRA, potentially reducing blurring artifacts. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;50:1808-1816.

BACKGROUNDRV144 is the only preventive HIV vaccine regimen demonstrating efficacy in humans. Attempting to build upon RV144 immune responses, we conducted a phase 1, multicenter, randomized, double-blind trial to assess the safety and immunogenicity of regimens substituting the DNA-HIV-PT123 (DNA) vaccine for ALVAC-HIV in different sequences or combinations with AIDSVAX B/E (protein).METHODSOne hundred and four HIV-uninfected participants were randomized to 4 treatment groups (T1, T2, T3, and T4) and received intramuscular injections at 0, 1, 3, and 6 months (M): T1 received protein at M0 and M1 and DNA at M3 and M6; T2 received DNA at M0 and M1 and protein at M3 and M6; T3 received DNA at M0, M1, M3, and M6 with protein coadministered at M3 and M6; and T4 received protein and DNA coadministered at each vaccination visit.RESULTSAll regimens were well tolerated. Antibodies binding to gp120 and V1V2 scaffold were observed in 95%-100% of participants in T3 and T4, two weeks after final vaccination at high magnitude. While IgG3 responses were highest in T3, a lower IgA/IgG ratio was observed in T4. Binding antibodies persisted at 12 months in 35%-100% of participants. Antibody-dependent cell-mediated cytotoxicity and tier 1 neutralizing-antibody responses had higher response rates for T3 and T4, respectively. CD4+ T cell responses were detectable in all treatment groups (32%-64%) without appreciable CD8+ T cell responses.CONCLUSIONThe DNA/protein combination regimens induced high-magnitude and long-lasting HIV V1V2-binding antibody responses, and early coadministration of the 2 vaccines led to a more rapid induction of these potentially protective responses.TRIAL REGISTRATIONClinicalTrials.gov NCT02207920.FUNDINGNational Institute of Allergy and Infectious Diseases (NIAID) grants UM1 AI068614, UM1 AI068635, UM1 AI068618, UM1 AI069511, UM1 AI069470, UM1 AI069534, P30 AI450008, UM1 AI069439, UM1 AI069481, and UM1 AI069496; the National Center for Advancing Translational Sciences, NIH (grant UL1TR001873); and the Bill & Melinda Gates Foundation (grant OPP52845).

Halide perovskites are promising semiconductors for inexpensive, high-performance optoelectronics. Despite a remarkable defect tolerance compared to conventional semiconductors, perovskite thin films still show substantial microscale heterogeneity in key properties such as luminescence efficiency and device performance. However, the origin of the variations remains a topic of debate, and a precise understanding is critical to the rational design of defect management strategies. Through a multi-scale investigation - combining correlative synchrotron scanning X-ray diffraction and time-resolved photoluminescence measurements on the same scan area - we reveal that lattice strain is directly associated with enhanced defect concentrations and non-radiative recombination. The strain patterns have a complex heterogeneity across multiple length scales. We propose that strain arises during the film growth and crystallization and provides a driving force for defect formation. Our work sheds new light on the presence and influence of structural defects in halide perovskites, revealing new pathways to manage defects and eliminate losses.

Methylammonium lead triiodide (MAPbI3) perovskite solar cells have gained significant attention with an impressive certified power conversion efficiency of 22.1%. Suppression of recombination at the interface and grain boundaries is critical to achieve high performance perovskite solar cells (PSCs). Here, we report a simple method to improve the performance of PSCs by incorporating a lead chloride (PbCl2) material into the MAPbI3 perovskite precursor through a Lewis acid–base adduct. The optimal concentration of PbCl2 that helps increase the grain size of MAPbI3 with introduction of the ideal amount secondary phases (lead iodide and methylammonium lead tri-chloride) is 2.5% (molar ratio, relative to lead iodide). Examination by steady-state photoluminescence and time-resolved photoluminescence has shown that devices based on MAPbI3-2.5% of PbCl2 facilitated longer charge carrier lifetime and electron–hole collection efficiency which is ascribed to reduced defects and concurrent improved material crystallinity. Electrochemical impedance spectra (EIS) of the corresponding PSCs have revealed that, compared to the pristine MAPbI3 perovskite film, the 2.5% PbCl2-additive increased the recombination resistance of the PSCs by 2.4-fold. Meanwhile, measurement of the surface potential of the perovskite films has indicated that the PbCl2-additive modifies the electronic properties of the film, shifting the fermi-level of the MAPbI3 film by 90 meV, leading to a more favourable energetic band matching for charge transfer. As a result, the performance of PSCs is enhanced from an average efficiency of 16.5% to an average efficiency of 18.1% with maximum efficiency reaching 19% due to the significantly improved fill-factor (from 0.69 to 0.76), while the hysteresis effect is also suppressed with the PbCl2-additive.

Perovskite materials have generated significant interest from academia and industry as a potential component in next-generation, high-efficiency, low-cost, photovoltaic (PV) devices. The record efficiency reported for perovskite solar cells has risen rapidly, and is now more than 22%. However, due to their complex dynamic behaviour, the process of measuring the efficiency of perovskite solar cells appears to be much more complicated than for other technologies. It has long been acknowledged that this is likely to greatly reduce the reliability of reported efficiency measurements, but the quantitative extent to which this occurs has not been determined. To investigate this, we conduct the first major inter-comparison of this PV technology. The participants included two labs accredited for PV performance measurement (CSIRO and NREL) and eight PV research laboratories. We find that the inter-laboratory measurement variability can be almost ten times larger for a slowly responding perovskite cell than for a control silicon cell. We show that for such a cell, the choice of measurement method, far more so than measurement hardware, is the single-greatest cause for this undesirably large variability. We provide recommendations for identifying the most appropriate method for a given cell, depending on its stabilisation and degradation behaviour. The results of this study suggest that identifying a consensus technique for accurate and meaningful efficiency measurements of perovskite solar cells will lead to an immediate improvement in reliability. This, in turn, should assist device researchers to correctly evaluate promising new materials and fabrication methods, and further boost the development of this technology.

3D printing facilitates the creation of accurate physical models of patient-specific anatomy from medical imaging datasets. While the majority of models to date are created from computed tomography (CT) data, there is increasing interest in creating models from other datasets, such as ultrasound and magnetic resonance imaging (MRI). MRI, in particular, holds great potential for 3D printing, given its excellent tissue characterization and lack of ionizing radiation. There are, however, challenges to 3D printing from MRI data as well. Here we review the basics of 3D printing, explore the current strengths and weaknesses of printing from MRI data as they pertain to model accuracy, and discuss considerations in the design of MRI sequences for 3D printing. Finally, we explore the future of 3D printing and MRI, including creative applications and new materials. Level of Evidence: 5 J. Magn. Reson. Imaging 2016.

The recent rise in power conversion efficiencies reported for perovskite solar cells has been a remarkable development in photovoltaics research. It is now pressing that the technology transitions from a research phenomenon to a real-world deployable device: this will require both robust methods for efficiency measurement, and accurate models for performance variation at different conditions. However, the generally slow response of perovskite solar cells to changes in voltage bias and irradiance, and the susceptibility of these cells to degradation, presents significant challenges. In this paper, we investigate current and voltage stabilisation of planar CH3NH3PbI3 perovskite solar cells and observe remarkably large variations in stabilisation time depending on exposure history. To address this, we demonstrate a dynamic approach that continues device pre-conditioning until pre-determined stability criteria are met. This approach is then employed to obtain measurements of short-circuit current and open-circuit voltage temperature coefficients under quasi-steady-state conditions for perovskite devices and a control monocrystalline silicon cell. The obtained open-circuit voltage temperature coefficient for the perovskite is −2700 ppm/°C, which interestingly, is similar to typically reported values for crystalline silicon devices. It is shown that the implemented approach can successfully differentiate between transient responses to the onset of illumination and true temperature related changes. We also find new manifestations of the complex transient processes that occur in perovskite devices. These observations highlight the importance of sophisticated characterisation approaches for correct characterisation of the performance of perovskite solar cells. Copyright © 2016 John Wiley & Sons, Ltd.

We report the synthesis and properties of new ruthenium-p-cymene complexes [(η6- -cymene)Ru(L)Cl][Cl] prepared from tetracarboxylic acid ligands L = 3,3′,4,4′-tetracarboxylicacid-2,2′-bipyridine (3,3′,4,4′-H4tcbpy), their methyl and ethyl ester derivatives (R4tcbpy), 4,4′,5,5′-tetracarboxylicacid-2,2′-bipyridine (4,4′,5,5′-H4tcbpy), and 4,4′-di-n-nonyl bipyridine (4,4′-dnbpy). The complexes were fully characterized by NMR, IR, MS, elemental analysis, UV–vis spectroscopy, and cyclic voltammetry. The single-crystal structure of [(η6-p-cymene)Ru(4,4′,5,5′-H4tcbpy)Cl]Cl 2 shows a ‘piano stool’ geometry with Ru-C (2.177(2)-2.231(2) A), Ru-N (2.0791–2.0801 A) distances and an N-Ru-N bond angle (77.4°) similar to equivalents in the 4,4′-dicarboxylic acid sister complex. Compared to the latter and also the 4,4′-dnbpy derivative 3, the UV–vis spectra show MLTC absorptions of the tetracarboxylates shifted to lower energy. The CVs show Ru(II/III) oxidation processes at 0.56–0.98 V (vs Fc/Fc+), depending on the ligand substitution. Changes in the electronic situation at the Ru centre reflected in the UV–vis and voltammetric data are correlated to HOMO levels calculated from photoelectron spectroscopy in air spectra recorded for all complexes. According to NMR experiments rapid ligand dissociation occurred when dissolving [(η6-p-cymene)Ru(3,3′,4,4′-Me4tcbpy)Cl]Cl 1b in DMF. In hot DMF decarboxylation led to the isolation of the 4′-dicarboxylic acid complex derivative.