Quantifying Chemical Reactions and Interfacial Properties at Buried Polymer/Polymer Interfaces.

Maleic anhydride (MAH)-modified polymers are used as tie layers for binding dissimilar polymers in multilayer polymer films. The MAH chemistry which promotes adhesion is well characterized in the bulk; however, only recently has the interfacial chemistry been studied. Sum frequency generation vibrational spectroscopy (SFG) is an interfacial spectroscopy technique which provides detailed information on interfacial chemical reactions, species, and molecular orientations and has been essential for characterizing the MAH chemistry in both nylon and ethyl vinyl alcohol copolymer (EVOH) model systems and coextruded multilayer films. Here, we further characterize the interfacial chemistry between MAH-modified polyethylene tie layers and both EVOH and nylon by investigating the model systems over a range of MAH concentrations. We can detect the interfacial chemical reaction products between MAH and the barrier layer at MAH concentrations of ≥0.022 wt % for nylon and ≥0.077 wt % for EVOH. Additionally, from the concentration-dependent reaction reactant/product SFG peak positions and the product imide or ester/acid C═O group tilt angles extracted from the polarization-dependent SFG spectra, we quantitatively observe concentration-dependent changes to both the interfacial chemistry and interfacial structure. The interfacial chemistry and molecular orientation as a function of MAH concentration are well correlated with the adhesion strength, providing important quantitative information for the future design of MAH-modified tie layers for a variety of important applications.

Corn Oil-Water Separation: Interfacial Behavior of Extended Surfactant and Glutelin.

The purification and collection of various products from oil/water mixtures are routine procedures. However, the presence of emulsifiers that can displace other surface active components in the mixtures can significantly influence the efficiency of such procedures. Previously, we investigated interfacial mechanisms of zein protein-induced emulsification and the opposing surfactant-induced demulsification related to corn oil refinement. In this paper, we further investigated a different class of protein, glutelin, inside corn and proved that glutelin acts as an oil/water emulsifier in an acidic water environment. Furthermore, an extended surfactant's protein disordering and removal ability was tested and compared with a conventional surfactant. An extended surfactant contains a poly(propylene oxide) or poly(propylene oxide)-poly(ethylene oxide) chain inserted between the hydrophilic head and the hydrophobic tail. In this study, a nonlinear optical spectroscopic technique, sum frequency generation (SFG) vibration spectroscopy, was used to study the behavior of glutelin and extended as well as regular surfactants at the corn oil/water or aqueous solution interface. In most cases, the conventional surfactant shows better protein disordering or removal ability than the extended surfactant. However, with the addition of heat and salt to an extended surfactant solution, the experiment resulted in a substantial increase in the extended surfactant's protein disorder or removal ability.

Magnetic Effect of Dopants on Bright and Dark Excitons in Strongly Confined Mn-Doped CsPbI3 Quantum Dots.

We investigated the magnetic effect of Mn2+ ions on an exciton of Mn-doped CsPbI3 quantum dots (QDs), where we looked for the signatures of an exciton magnetic polaron known to produce a large effective magnetic field in Mn-doped CdSe QDs. In contrast to Mn-doped CdSe QDs that can produce ∼100 T of magnetic field upon photoexcitation, manifested as a large change in the energy and relaxation dynamics of a bright exciton, Mn-doped CsPbI3 QDs exhibited little influence of a magnetic dopant on the behavior of a bright exciton. However, a µs-lived dark exciton in CsPbI3 QDs showed 40% faster decay in the presence of Mn2+, equivalent to the effect of ∼3 T of an external magnetic field. While further study is necessary to fully understand the origin of the large difference in the magneto-optic property of an exciton in two systems, we consider that the difference in antiferromagnetic coupling of the dopants is an important contributing factor.

Intense Dark Exciton Emission from Strongly Quantum-Confined CsPbBr3 Nanocrystals.

Dark exciton as the lowest-energy (ground) exciton state in metal halide perovskite nanocrystals is a subject of much interest. This is because the superior performance of perovskites as the photon source combined with long lifetime of dark exciton can be attractive for many applications of exciton. However, the direct observation of the intense and long-lived dark exciton emission, indicating facile access to dark ground exciton state, has remained elusive. Here, we report the intense photoluminescence from dark exciton with microsecond lifetime in strongly confined CsPbBr3 nanocrystals and reveal the crucial role of confinement in accessing the dark ground exciton state. This study establishes the potential of strongly quantum-confined perovskite nanostructures as the excellent platform to harvest the benefits of extremely long-lived dark exciton.

Spinal Manipulation vs Prescription Drug Therapy for Chronic Low Back Pain: Beliefs, Satisfaction With Care, and Qualify of Life Among Older Medicare Beneficiaries.

OBJECTIVE: The objective of this study was to compare patients' perspectives on the use of spinal manipulative therapy (SMT) compared to prescription drug therapy (PDT) with regard to health-related quality of life (HRQoL), patient beliefs, and satisfaction with treatment. METHODS: Four cohorts of Medicare beneficiaries were assembled according to previous treatment received as evidenced in claims data: SMT, PDT, and 2 crossover cohorts (where participants experienced both types of treatments). A total of 195 Medicare beneficiaries responded to the survey. Outcome measures used were a 0-to-10 numeric rating scale to measure satisfaction, the Low Back Pain Treatment Beliefs Questionnaire to measure patient beliefs, and the 12-item Short Form Health Survey to measure HRQoL. RESULTS: Recipients of SMT were more likely to be very satisfied with their care (84%) than recipients of PDT (50%; P = .002). The SMT cohort self-reported significantly higher HRQoL compared to the PDT cohort; mean differences in physical and mental health scores on the 12-item Short Form Health Survey were 12.85 and 9.92, respectively. The SMT cohort had a lower degree of concern regarding chiropractic care for their back pain compared to the PDT cohort's reported concern about PDT (P = .03). CONCLUSION: Among older Medicare beneficiaries with chronic low back pain, long-term recipients of SMT had higher self-reported rates of HRQoL and greater satisfaction with their modality of care than long-term recipients of PDT. Participants who had longer-term management of care were more likely to have positive attitudes and beliefs toward the mode of care they received.

Size-dependent dark exciton properties in cesium lead halide perovskite quantum dots.

The fine structure of the band edge exciton and the dark exciton photoluminescence (PL) are topics of significant interest in the research of semiconducting metal halide perovskite nanocrystals, with several conflicting reports on the level ordering of the bright and dark states and the accessibility of the emitting dark states. Recently, we observed the intense dark exciton PL in strongly confined CsPbBr3 nanocrystals at cryogenic temperatures, in contrast to weakly confined nanocrystals lacking dark exciton PL, which was explained by the confinement enhanced bright-dark exciton splitting. In this work, we investigated the size-dependence of the dark exciton photoluminescence properties in CsPbBr3 and CsPbI3 quantum dots in the strongly confined regime, showing the clear role of confinement in determining the bright-dark energy splitting (ΔEBD) and the dark exciton lifetime (τD). We observe the increase in both ΔEBD and τD with increasing quantum confinement in CsPbBr3 and CsPbI3 QDs, consistent with the earlier predictions on the size-dependence of ΔEBD and τD. Our results show that quantum confinement plays a crucial role in determining the accessibility to the dark exciton PL and its characteristics in metal halide perovskite nanocrystals.

On the determination of absorption cross section of colloidal lead halide perovskite quantum dots.

The absorption cross section of lead halide perovskite nanocrystals is important for understanding their photophysical properties, especially those depending on the density of photoexcited charge carriers. Despite its importance, there are large discrepancies among the reported absorption cross section values determined employing different methods. Here, we measured the absorption cross section of CsPbBr3 quantum dots (QDs) of varying sizes using elemental analysis and transient absorption (TA) saturation methods and compared with the previously reported values determined from elemental analysis and transient photoluminescence (PL) saturation methods. A careful comparison indicates that the reliable absorption cross section of lead halide perovskite QDs is obtained from both elemental analysis and TA saturation methods, while many previously reported values determined from the PL saturation method underestimate the absorption cross section.

Precise Control of Quantum Confinement in Cesium Lead Halide Perovskite Quantum Dots via Thermodynamic Equilibrium.

Cesium lead halide (CsPbX3) nanocrystals have emerged as a new family of materials that can outperform the existing semiconductor nanocrystals due to their superb optical and charge-transport properties. However, the lack of a robust method for producing quantum dots with controlled size and high ensemble uniformity has been one of the major obstacles in exploring the useful properties of excitons in zero-dimensional nanostructures of CsPbX3. Here, we report a new synthesis approach that enables the precise control of the size based on the equilibrium rather than kinetics, producing CsPbX3 quantum dots nearly free of heterogeneous broadening in their exciton luminescence. The high level of size control and ensemble uniformity achieved here will open the door to harnessing the benefits of excitons in CsPbX3 quantum dots for photonic and energy-harvesting applications.

Risk Factors Associated With Early Complications of Revision Surgery for Head-Neck Taper Corrosion in Metal-on-Polyethylene Total Hip Arthroplasty.

BACKGROUND: Adverse local tissue reactions (ALTRs) due to tribocorrosion of head-neck taper junctions in contemporary metal-on-polyethylene (MoP) total hip arthroplasty (THA) are emerging as an important reason for failure requiring revision surgery. This study aimed at: (1) reporting early complication rates and outcome, and (2) identifying risk factors associated with complications of revision surgery for head-neck taper corrosion in patients with MoP THA. METHODS: Forty consecutive revision surgeries in 39 patients (male, 16; female, 23) with MoP THA were evaluated. The follow-up period after revision was a minimum of 14 months (range, 14-45). The indication for revision surgery was the presence of symptomatic ALTR on magnetic resonance imaging (MRI) with elevated metal ion levels. RESULTS: The overall complication rate was 25% and the reoperation rate was 10%. The median serum level of cobalt ions decreased significantly 8.2 µg/L (1.2-56.1 µg/L) pre-revision to 3.1 µg/L (0.2-14.0 µg/L) post-revision (P < .01). High fretting and corrosion grades (Goldberg score ≥ 3) were observed in 82% of retrieved implants. MRI findings of solid lesion(s) with abductor deficiency (P < .01) and intraoperative tissue damage at revision (P = .02) were significantly associated with post-revision complications. CONCLUSION: A high rate of early complications (25%) and re-revisions (10%) was observed after revision of ALTR associated with head-neck taper corrosion. Pre-revision MRI findings of solid lesion(s) with abductor deficiency and intraoperative tissue damage were risk factors associated with the occurrence of a complication after revision surgery. This information provides clinically useful information for clinical decision-making and preoperative counseling of MoP THA patients undergoing revision surgery for head-neck taper corrosion.

Photoinduced Anion Exchange in Cesium Lead Halide Perovskite Nanocrystals.

Cesium lead halide (CsPbX3) perovskite nanocrystals (NCs) possess the unique capability of post-synthesis anion exchange providing facile tunability of the optical properties, which is usually achieved by mixing NCs with reactive anion precursors. In this work, we show that the controllable anion exchange can be achieved in a dihalomethane solution of CsPbX3 NC in the absence of any spontaneously reacting anion source using photoexcitation of CsPbX3 NCs as the triggering mechanism for the halide ion exchange. The reaction begins with the photoinduced electron transfer from CsPbX3 NCs to dihalomethane solvent molecules producing halide ions via reductive dissociation, which is followed by anion exchange. The reaction proceeds only in the presence of excitation light and the rate and extent of reaction can be controlled by varying the light intensity. Furthermore, the asymptotic extent of reaction under continuous excitation can be controlled by varying the wavelength of light that self-limits the reaction when light becomes off-resonance with the absorption of NCs. The light-controlled anion exchange demonstrated here can be utilized to pattern the post-synthesis chemical transformation of CsPbX3 NCs, not readily achievable using typical methods of anion exchange.

Photoemission of Energetic Hot Electrons Produced via Up-Conversion in Doped Quantum Dots.

The benefits of the hot electrons from semiconductor nanostructures in photocatalysis or photovoltaics result from their higher energy compared to that of the band-edge electrons facilitating the electron-transfer process. The production of high-energy hot electrons usually requires short-wavelength UV or intense multiphoton visible excitation. Here, we show that highly energetic hot electrons capable of above-threshold ionization are produced via exciton-to-hot-carrier up-conversion in Mn-doped quantum dots under weak band gap excitation (∼10 W/cm2) achievable with the concentrated solar radiation. The energy of hot electrons is as high as ∼0.4 eV above the vacuum level, much greater than those observed in other semiconductor or plasmonic metal nanostructures, which are capable of performing energetically and kinetically more-challenging electron transfer. Furthermore, the prospect of generating solvated electron is unique for the energetic hot electrons from up-conversion, which can open a new door for long-range electron transfer beyond short-range interfacial electron transfer.

Nonplasmonic Hot-Electron Photocurrents from Mn-Doped Quantum Dots in Photoelectrochemical Cells.

We report the measurement of the hot-electron current in a photoelectrochemical cell constructed from a glass/ITO/Al2 O3 (ITO=indium tin oxide) electrode coated with Mn-doped quantum dots, where hot electrons with a large excess kinetic energy were produced through upconversion of the excitons into hot electron hole pairs under photoexcitation at 3 eV. In our recent study (J. Am. Chem. Soc. 2015, 137, 5549), we demonstrated the generation of hot electrons in Mn-doped II-VI semiconductor quantum dots and their usefulness in photocatalytic H2 production reaction, taking advantage of the more efficient charge transfer of hot electrons compared with band-edge electrons. Here, we show that hot electrons produced in Mn-doped CdS/ZnS quantum dots possess sufficient kinetic energy to overcome the energy barrier from a 5.4-7.5 nm thick Al2 O3 layer producing a hot-electron current in photoelectrochemical cell. This work demonstrates the possibility of harvesting hot electrons not only at the interface of the doped quantum dot surface, but also far away from it, thus taking advantage of the capability of hot electrons for long-range electron transfer across a thick energy barrier.

Identification of a cell-of-origin for fibroblasts comprising the fibrotic reticulum in idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a progressive disease of the middle aged and elderly with a prevalence of one million persons worldwide. The fibrosis spreads from affected alveoli into contiguous alveoli, creating a reticular network that leads to death by asphyxiation. Lung fibroblasts from patients with IPF have phenotypic hallmarks, distinguishing them from their normal counterparts: pathologically activated Akt signaling axis, increased collagen and α-smooth muscle actin expression, distinct gene expression profile, and ability to form fibrotic lesions in model organisms. Despite the centrality of these fibroblasts in disease pathogenesis, their origin remains uncertain. Here, we report the identification of cells in the lungs of patients with IPF with the properties of mesenchymal progenitors. In contrast to progenitors isolated from nonfibrotic lungs, IPF mesenchymal progenitor cells produce daughter cells manifesting the full spectrum of IPF hallmarks, including the ability to form fibrotic lesions in zebrafish embryos and mouse lungs, and a transcriptional profile reflecting these properties. Morphological analysis of IPF lung tissue revealed that mesenchymal progenitor cells and cells with the characteristics of their progeny comprised the fibrotic reticulum. These data establish that the lungs of patients with IPF contain pathological mesenchymal progenitor cells that are cells of origin for fibrosis-mediating fibroblasts. These fibrogenic mesenchymal progenitors and their progeny represent an unexplored target for novel therapies to interdict fibrosis.

Exploiting the Features of Clinical Judgment to Improve Assessment of Disease Severity in the Emergency Department: An Acutelines Study.

BACKGROUND: Clinical judgment, also known as gestalt or gut feeling, can predict deterioration and can be easily and rapidly obtained. To date, it is unknown what clinical judgement precisely entails. The aim of this study was to elucidate which features define the clinical impression of health care professionals in the ED. METHOD: A nominal group technique (NGT) was used to develop a consensus-based instrument to measure the clinical impression score (CIS, scale 1-10) and to identify features associated with either a more severe or less severe estimated disease severity. This single-center observational cohort study included 517 medical patients visiting the ED. The instrument was prospectively validated.. The predictive value of each feature for the clinical impression was assessed using multivariate linear regression analyses to adjust for potential confounders and validated in the infection group. RESULTS: The CIS at the ED was associated with ICU admission (OR 1.67 [1.37-2.03], p < 0.001), in-hospital mortality (OR 2.25 [1.33-3.81], p < 0.001), and 28-day mortality (OR 1.33 [1.07-1.65], <0.001). Dry mucous membranes, eye glance, red flags during physical examination, results of arterial blood gas analysis, heart and respiratory rate, oxygen modality, triage urgency, and increased age were associated with a higher estimated disease severity (CIS). On the other hand, behavior of family, self-estimation of the patient, systolic blood pressure, and Glascow Coma Scale were associated with a lower estimated disease severity (CIS). CONCLUSION: We identified several features that were associated with the clinical impression of health care professionals in the ED. Translating the subjective features and objective measurements into quantifiable parameters may aid the development of a novel triage tool to identify patients at risk of deterioration in the ED.

Bridging the Gap: A Systematic Review on Reporting Baseline Characteristics, Process, and Outcome Parameters in Rectosigmoid Hirschsprung's Disease.

The variation in standardized, well-defined parameters in Hirschsprung's disease (HSCR) research hinders overarching comparisons and complicates evaluations of care quality across healthcare settings. This review addresses the significant variability observed in these parameters as reported in recent publications. The goal is to compile a list of commonly described baseline characteristics, process and outcome measures, and to investigate disparities in their utilization and definitions. A systematic review of literature on the primary care process for HSCR was performed according to PRISMA guidelines. Relevant literature published between 2015 and 2021 was obtained by combining the search term "Hirschsprung's disease" with "treatment outcome," "complications," "mortality," "morbidity," and "survival" in Medline, Embase, and the Cochrane Library. We extracted study characteristics, reported process and outcome parameters, and patient and disease characteristics. We extracted 1,026 parameters from 200 publications and categorized these into patient characteristics (n = 226), treatment and care process characteristics (n = 199), and outcomes (n = 601). A total of 116 parameters were reported in more than 5% of publications. The most frequently reported characteristics were sex (88%), age at the time of surgery (66%), postoperative Hirschsprung-associated enterocolitis (64%), type of repair (57%), fecal incontinence (54%), and extent of aganglionosis (51%). This review underscores the pronounced variation in reported parameters within HSCR studies, highlighting the necessity for consistent, well-defined measures and reporting systems to foster improved data interpretability. Moreover, it advocates for the use of these findings in the development of a Core Indicator Set, complementing the recently developed Core Outcome Set. This will facilitate quality assessments across pediatric surgical centers throughout Europe.

Traditional food: a better compatibility with industry requirements.

The objective of this article is to summarise the main results of the TRUEFOOD Integrated project, which is supported by the European Commission in the European Framework Program 6 (FP6). This project started in 2006 and ended in 2010. TRUEFOOD aimed to improve quality and safety and introduce innovation into Traditional European Food production systems through research, demonstration, dissemination and training activities. It focuses on increasing value to both consumers and producers and on supporting the development of realistic business plans for all components of the food chain, using a farm-to-fork approach.

Heterostructures of Cu2-xS/Cu2-xTe plasmonic semiconductors: disappearing and reappearing LSPR with anion exchange.

Localized surface plasmon resonance (LSPR) of Cu2-xS nanorods is quenched during the initial Cu2-xS/Cu2-xTe core/shell stage of anion exchange then returns as Cu2-xTe progresses into the nanorod. Phase change within the core accounts for this behaviour illustrating the complexity emergent from anion exchange.

Initial Choice of Spinal Manipulation Reduces Escalation of Care for Chronic Low Back Pain Among Older Medicare Beneficiaries.

STUDY DESIGN: We combined elements of cohort and crossover-cohort design. OBJECTIVE: The objective of this study was to compare longterm outcomes for spinal manipulative therapy (SMT) and opioid analgesic therapy (OAT) regarding escalation of care for patients with chronic low back pain (cLBP). SUMMARY OF BACKGROUND DATA: Current evidence-based guidelines for clinical management of cLBP include both OAT and SMT. For long-term care of older adults, the efficiency and value of continuing either OAT or SMT are uncertain. METHODS: We examined Medicare claims data spanning a five-year period. We included older Medicare beneficiaries with an episode of cLBP beginning in 2013. All patients were continuously enrolled under Medicare Parts A, B, and D. We analyzed the cumulative frequency of encounters indicative of an escalation of care for cLBP, including hospitalizations, emergency department visits, advanced diagnostic imaging, specialist visits, lumbosacral surgery, interventional pain medicine techniques, and encounters for potential complications of cLBP. RESULTS: SMT was associated with lower rates of escalation of care as compared to OAT. The adjusted rate of escalated care encounters was approximately 2.5 times higher for initial choice of OAT vs. initial choice of SMT (with weighted propensity scoring: rate ratio 2.67, 95% confidence interval 2.64-2.69, P < .0001). CONCLUSION: Among older Medicare beneficiaries who initiated long-term care for cLBP with opioid analgesic therapy, the adjusted rate of escalated care encounters was significantly higher as compared to those who initiated care with spinal manipulative therapy.Level of Evidence: 3.

Does the rural trauma team development course shorten the interval from trauma patient arrival to decision to transfer?

BACKGROUND: The Rural Trauma Team Development Course (RTTDC) was developed by the ad hoc Rural Trauma Committee of the American College of Surgeons, Committee on Trauma to address the increased mortality of the rural trauma patient. The effectiveness of the RTTDC in shortening the interval from patient arrival to decision to transfer and the effect on the transfer process of communication training emphasizing team building is the focus of this study. METHOD: Rural level III and level IV trauma centers (N=18) were enrolled in a multiinstitutional 3-month longitudinal study of transferred trauma patients. Results were compared with institutions having hosted RTTDC versus those institutions not yet exposed to the course. RESULTS: One-way analysis of variance was conducted. Results indicated that RTTDC training alone and RTTDC including communication training resulted in a statistically significantly shorter (p<0.05) time for decision to transfer. Transferring squad arrival time was also significantly reduced (p<0.01) as was the number of transferring squads contacted (p<0.01). No differences were observed among the trauma facilities and the number of receiving facilities contacted, (p=0.64) or in the time required to find an accepting facility (p=0.72). CONCLUSION: The RTTDC alone and with the embedded communication module significantly reduce delays in the transfer process of the rural trauma patient.