Quantum Diamonds at the Beach: Chemical Insights into Silica Growth on Nanoscale Diamond using Multimodal Characterization and Simulation.

Surface chemistry of materials that host quantum bits such as diamond is an important avenue of exploration as quantum computation and quantum sensing platforms mature. Interfacing diamond in general and nanoscale diamond (ND) in particular with silica is a potential route to integrate room temperature quantum bits into photonic devices, fiber optics, cells, or tissues with flexible functionalization chemistry. While silica growth on ND cores has been used successfully for quantum sensing and biolabeling, the surface mechanism to initiate growth was unknown. This report describes the surface chemistry responsible for silica bond formation on diamond and uses X-ray absorption spectroscopy (XAS) to probe the diamond surface chemistry and its electronic structure with increasing silica thickness. A modified Stöber (Cigler) method was used to synthesize 2-35 nm thick shells of SiO2 onto carboxylic acid-rich ND cores. The diamond morphology, surface, and electronic structure were characterized by overlapping techniques including electron microscopy. Importantly, we discovered that SiO2 growth on carboxylated NDs eliminates the presence of carboxylic acids and that basic ethanolic solutions convert the ND surface to an alcohol-rich surface prior to silica growth. The data supports a mechanism that alcohols on the ND surface generate silyl-ether (ND-O-Si-(OH)3) bonds due to rehydroxylation by ammonium hydroxide in ethanol. The suppression of the diamond electronic structure as a function of SiO2 thickness was observed for the first time, and a maximum probing depth of ∼14 nm was calculated. XAS spectra based on the Auger electron escape depth was modeled using the NIST database for the Simulation of Electron Spectra for Surface Analysis (SESSA) to support our experimental results. Additionally, resonant inelastic X-ray scattering (RIXS) maps produced by the transition edge sensor reinforces the chemical analysis provided by XAS. Researchers using diamond or high-pressure high temperature (HPHT) NDs and other exotic materials (e.g., silicon carbide or cubic-boron nitride) for quantum sensing applications may exploit these results to design new layered or core-shell quantum sensors by forming covalent bonds via surface alcohol groups.

SLAC microresonator RF (SMuRF) electronics: A tone-tracking readout system for superconducting microwave resonator arrays.

We describe the newest generation of the SLAC Microresonator RF (SMuRF) electronics, a warm digital control and readout system for microwave-frequency resonator-based cryogenic detector and multiplexer systems, such as microwave superconducting quantum interference device multiplexers (µmux) or microwave kinetic inductance detectors. Ultra-sensitive measurements in particle physics and astronomy increasingly rely on large arrays of cryogenic sensors, which in turn necessitate highly multiplexed readout and accompanying room-temperature electronics. Microwave-frequency resonators are a popular tool for cryogenic multiplexing, with the potential to multiplex thousands of detector channels on one readout line. The SMuRF system provides the capability for reading out up to 3328 channels across a 4-8 GHz bandwidth. Notably, the SMuRF system is unique in its implementation of a closed-loop tone-tracking algorithm that minimizes RF power transmitted to the cold amplifier, substantially relaxing system linearity requirements and effective noise from intermodulation products. Here, we present a description of the hardware, firmware, and software systems of the SMuRF electronics, comparing achieved performance with science-driven design requirements. In particular, we focus on the case of large-channel-count, low-bandwidth applications, but the system has been easily reconfigured for high-bandwidth applications. The system described here has been successfully deployed in lab settings and field sites around the world and is baselined for use on upcoming large-scale observatories.

Screening for Osteoporosis Risk Among Community-Dwelling Older Adults: A Scoping Review.

BACKGROUND AND PURPOSE: Due to potential health-related consequences of osteoporosis (OP), health care providers who do not order imaging, such as physical therapists, should be aware of OP screening tools that identify individuals who need medical and rehabilitation care. However, current knowledge and guidance on screening tools is limited. Therefore, we explored OP screening tools that are appropriate and feasible for physical therapy practice, and evaluated tools' effectiveness by examining their clinimetric properties. METHODS: A systematic search of the following databases was performed: PubMed, PEDro, PsycINFO, CINAHL, and Web of Science. Articles were included if the study population was 50 years and older, had a diagnosis of OP, if the screening tool was within the scope of physical therapy practice, and was compared to either a known diagnosis of OP or bone densitometry scan results. Included articles underwent multiple reviews for inclusion and exclusion, with each review round having a different randomly selected pair of reviewers. Data were extracted from included articles for participant demographics, outcome measures, cut-off values, and clinimetric properties. Results were categorized with positive and negative likelihood ratios (+LR/-LR) based on the magnitude of change in the probability of having or not having OP. RESULTS: +LRs ranged from 0.15 to 20.21, with the Fracture Risk Assessment Tool (FRAX) and Study of Osteoporotic Fractures (SOF) having a large shift in posttest probability. -LRs ranged from 0.03 to 1.00, with the FRAX, Male Osteoporosis Risk Estimation Scores, Osteoporosis Self-Assessment Tool (OST), and Simple Calculated Osteoporosis Risk Estimation having a large shift in posttest probability. CONCLUSION: Tools with moderate-large shift for both +LR and -LR recommended for use are: (1) OST; (2) FRAX; and (3) SOF. The variability in cut-off scores and clinimetric properties based on gender, age, and race/ethnicities made it impossible to provide one specific recommendation for an OP screening tool. Future research should focus on OP risk prediction among males and racial and ethnic groups.

Examining physical activity participation barriers among adults 50 years and older: a scoping review.

Background: Addressing physical activity (PA) barriers is essential for increasing PA levels in middle-aged and older adults. However, there are no recommendations on selecting PA barrier assessment tools. Objectives: Thus, we aimed to identify and provide clinimetric properties on PA barrier assessment tools that healthcare providers, exercise experts, and public health officials can use to examine potential barriers faced by community-dwelling adults 50 years and older. Methods: We performed a systematic search of the following databases: PubMed, PsycINFO, CINAHL, and Web of Science. Articles were included if they presented clinimetric data on a PA participation barrier assessment tool for community-dwelling participants with a mean age of 50 years and older. The 561 identified articles underwent multiple rounds of blinded reviews. Included articles underwent data extraction for participant characteristics, scoring, constructs, reference tests, and clinimetric properties. Results: The 35 included articles reported on 33 different PA participation barrier assessment tools. Eighteen articles reported on participants with cardiovascular, musculoskeletal, or neurological diagnoses, diabetes, hemodialysis, history of cancer, or mobility limitations. Tools with two or more supporting publications included the Exercise Benefits/Barrier Scale (EBBS), Episode-Specific Interpretations of Exercise Inventory (ESIE), and Inventory of Physical Activity and Barriers (IPAB). Due to differences in methodologies, across-tool comparison was not possible. Conclusion: The EBBS, ESIE, and IPAB are promising tools for community-dwelling adults 50 years and older. However, additional research is warranted to identify the best PA barrier assessment tool among adults 50 years and older.

Metastable Brominated Nanodiamond Surface Enables Room Temperature and Catalysis-Free Amine Chemistry.

Bromination of high-pressure, high-temperature (HPHT) nanodiamond (ND) surfaces has not been explored and can open new avenues for increased chemical reactivity and diamond lattice covalent bond formation. The large bond dissociation energy of the diamond lattice-oxygen bond is a challenge that prevents new bonds from forming, and most researchers simply use oxygen-terminated NDs (alcohols and acids) as reactive species. In this work, we transformed a tertiary-alcohol-rich ND surface to an amine surface with ∼50% surface coverage and was limited by the initial rate of bromination. We observed that alkyl bromide moieties are highly labile on HPHT NDs and are metastable as previously found using density functional theory. The strong leaving group properties of the alkyl bromide intermediate were found to form diamond-nitrogen bonds at room temperature and without catalysts. This robust pathway to activate a chemically inert ND surface broadens the modalities for surface termination, and the unique surface properties of brominated and aminated NDs are impactful to researchers for chemically tuning diamond for quantum sensing or biolabeling applications.

Examining physical activity participation barriers among adults 50 years and older: a scoping review protocol.

Background: Despite the benefits of physical activity (PA), 61% of adults 50 years and older do not meet the recommended levels of PA. One method of increasing PA participation is assessing and addressing PA participation barriers. Currently, no guidance on methodologies for assessing PA participation barriers exist. Objective: The primary objective of this scoping review is to map the methodologies used to examine potential PA participation barriers faced by community-dwelling adults 50 years and older. A secondary objective is to evaluate the clinimetric properties of these methodologies. Methods: This scoping review protocol is registered with Open Science Framework (https://osf.io/wd2hx). A systematic search of the following databases will be performed: PubMed, PsycINFO, CINAHL, Web of Science, and PEDro. Included studies will 1) present either a) data on development or clinimetric properties of PA participation barrier tool (s); or b) relative risk or odds ratios of PA participation barrier(s); 2) compare PA participation barriers or PA participation barrier tool(s) to either subjective or objective measures of PA; and 3) comprise of community-dwelling participants with a mean age of 50 years and older. A two-phase blinded independent screening process will be conducted to select the included publications. Data will be extracted using a standardized form and cross-checked by the first author. A narrative summary will accompany the results presented in tables and figures. Conclusion: This scoping review will provide a comprehensive understanding of current literature and gaps related to PA participation barrier methodologies used with adults 50 years and older.

Depth-dependent valence stratification driven by oxygen redox in lithium-rich layered oxide.

Lithium-rich nickel-manganese-cobalt (LirNMC) layered material is a promising cathode for lithium-ion batteries thanks to its large energy density enabled by coexisting cation and anion redox activities. It however suffers from a voltage decay upon cycling, urging for an in-depth understanding of the particle-level structure and chemical complexity. In this work, we investigate the Li1.2Ni0.13Mn0.54Co0.13O2 particles morphologically, compositionally, and chemically in three-dimensions. While the composition is generally uniform throughout the particle, the charging induces a strong depth dependency in transition metal valence. Such a valence stratification phenomenon is attributed to the nature of oxygen redox which is very likely mostly associated with Mn. The depth-dependent chemistry could be modulated by the particles' core-multi-shell morphology, suggesting a structural-chemical interplay. These findings highlight the possibility of introducing a chemical gradient to address the oxygen-loss-induced voltage fade in LirNMC layered materials.

Chemical control of competing electron transfer pathways in iron tetracyano-polypyridyl photosensitizers.

Photoinduced intramolecular electron transfer dynamics following metal-to-ligand charge-transfer (MLCT) excitation of [Fe(CN)4(2,2'-bipyridine)]2- (1), [Fe(CN)4(2,3-bis(2-pyridyl)pyrazine)]2- (2) and [Fe(CN)4(2,2'-bipyrimidine)]2- (3) were investigated in various solvents with static and time-resolved UV-Visible absorption spectroscopy and Fe 2p3d resonant inelastic X-ray scattering (RIXS). This series of polypyridyl ligands, combined with the strong solvatochromism of the complexes, enables the 1MLCT vertical energy to be varied from 1.64 eV to 2.64 eV and the 3MLCT lifetime to range from 180 fs to 67 ps. The 3MLCT lifetimes in 1 and 2 decrease exponentially as the MLCT energy increases, consistent with electron transfer to the lowest energy triplet metal-centred (3MC) excited state, as established by the Tanabe-Sugano analysis of the Fe 2p3d RIXS data. In contrast, the 3MLCT lifetime in 3 changes non-monotonically with MLCT energy, exhibiting a maximum. This qualitatively distinct behaviour results from a competing 3MLCT → ground state (GS) electron transfer pathway that exhibits energy gap law behaviour. The 3MLCT → GS pathway involves nuclear tunnelling for the high-frequency polypyridyl breathing mode (hν = 1530 cm-1), which is most displaced for complex 3, making this pathway significantly more efficient. Our study demonstrates that the excited state relaxation mechanism of Fe polypyridyl photosensitizers can be readily tuned by ligand and solvent environment. Furthermore, our study reveals that extending charge transfer lifetimes requires control of the relative energies of the 3MLCT and the 3MC states and suppression of the intramolecular distortion of the acceptor ligand in the 3MLCT excited state.

Soft X-ray spectroscopy with transition-edge sensors at Stanford Synchrotron Radiation Lightsource beamline 10-1.

We present results obtained with a new soft X-ray spectrometer based on transition-edge sensors (TESs) composed of Mo/Cu bilayers coupled to bismuth absorbers. This spectrometer simultaneously provides excellent energy resolution, high detection efficiency, and broadband spectral coverage. The new spectrometer is optimized for incident X-ray energies below 2 keV. Each pixel serves as both a highly sensitive calorimeter and an X-ray absorber with near unity quantum efficiency. We have commissioned this 240-pixel TES spectrometer at the Stanford Synchrotron Radiation Lightsource beamline 10-1 (BL 10-1) and used it to probe the local electronic structure of sample materials with unprecedented sensitivity in the soft X-ray regime. As mounted, the TES spectrometer has a maximum detection solid angle of 2 × 10-3 sr. The energy resolution of all pixels combined is 1.5 eV full width at half maximum at 500 eV. We describe the performance of the TES spectrometer in terms of its energy resolution and count-rate capability and demonstrate its utility as a high throughput detector for synchrotron-based X-ray spectroscopy. Results from initial X-ray emission spectroscopy and resonant inelastic X-ray scattering experiments obtained with the spectrometer are presented.

Synthesis of a copper-supported triplet nitrene complex pertinent to copper-catalyzed amination.

Terminal copper-nitrenoid complexes have inspired interest in their fundamental bonding structures as well as their putative intermediacy in catalytic nitrene-transfer reactions. Here, we report that aryl azides react with a copper(I) dinitrogen complex bearing a sterically encumbered dipyrrin ligand to produce terminal copper nitrene complexes with near-linear, short copper-nitrenoid bonds [1.745(2) to 1.759(2) angstroms]. X-ray absorption spectroscopy and quantum chemistry calculations reveal a predominantly triplet nitrene adduct bound to copper(I), as opposed to copper(II) or copper(III) assignments, indicating the absence of a copper-nitrogen multiple-bond character. Employing electron-deficient aryl azides renders the copper nitrene species competent for alkane amination and alkene aziridination, lending further credence to the intermediacy of this species in proposed nitrene-transfer mechanisms.

Surface-to-Bulk Redox Coupling through Thermally Driven Li Redistribution in Li- and Mn-Rich Layered Cathode Materials.

Li- and Mn-rich (LMR) layered cathode materials have demonstrated impressive capacity and specific energy density thanks to their intertwined redox centers including transition metal cations and oxygen anions. Although tremendous efforts have been devoted to the investigation of the electrochemically driven redox evolution in LMR cathode at ambient temperature, their behavior under a mildly elevated temperature (up to ∼100 °C), with or without electrochemical driving force, remains largely unexplored. Here we show a systematic study of the thermally driven surface-to-bulk redox coupling effect in charged Li1.2Ni0.15Co0.1Mn0.55O2. We for the first time observed a charge transfer between the bulk oxygen anions and the surface transition metal cations under ∼100 °C, which is attributed to the thermally driven redistribution of Li ions. This finding highlights the nonequilibrium state and dynamic nature of the LMR material at deeply delithiated state upon a mild temperature perturbation.

Lynx x-ray microcalorimeter.

Lynx is an x-ray telescope, one of four large satellite mission concepts currently being studied by NASA to be a flagship mission. One of Lynx's three instruments is an imaging spectrometer called the Lynx x-ray microcalorimeter (LXM), an x-ray microcalorimeter behind an x-ray optic with an angular resolution of 0.5 arc sec and ∼2 m2 of area at 1 keV. The LXM will provide unparalleled diagnostics of distant extended structures and, in particular, will allow the detailed study of the role of cosmic feedback in the evolution of the Universe. We discuss the baseline design of LXM and some parallel approaches for some of the key technologies. The baseline sensor technology uses transition-edge sensors, but we also consider an alternative approach using metallic magnetic calorimeters. We discuss the requirements for the instrument, the pixel layout, and the baseline readout design, which uses microwave superconducting quantum interference devices and high-electron mobility transistor amplifiers and the cryogenic cooling requirements and strategy for meeting these requirements. For each of these technologies, we discuss the current technology readiness level and our strategy for advancing them to be ready for flight. We also describe the current system design, including the block diagram, and our estimate for the mass, power, and data rate of the instrument.

Use of Transition Models to Design High Performance TESs for the LCLS-II Soft X-Ray Spectrometer.

We are designing an array of transition-edge sensor (TES) microcalorimeters for a soft X-ray spectrometer at the Linac Coherent Light Source at SLAC National Accelerator Laboratory to coincide with upgrades to the free electron laser facility. The complete spectrometer will have 1000 TES pixels with energy resolution of 0.5 eV full-width at half-maximum (FWHM) for incident energies below 1 keV while maintaining pulse decay-time constants shorter than 100 µs. Historically, TES pixels have often been designed for a particular scientific application via a combination of simple scaling relations and trial-and-error experimentation with device geometry. We have improved upon this process by using our understanding of transition physics to guide TES design. Using the two-fluid approximation of the phase-slip line model for TES resistance, we determine how the geometry and critical temperature of a TES will affect the shape of the transition. We have used these techniques to design sensors with a critical temperature of 55 mK. The best sensors achieve an energy resolution of 0.75 eV FWHM at 1.25 keV. Building upon this result, we show how the next generation of sensors can be designed to reach our goal of 0.5 eV resolution.

Readiness for Clinical Practice Promoting Safe Student Performance in Physical Therapy Education.

BACKGROUND: Physical therapy educators have a responsibility to graduate entry-level PTs who can provide safe high-quality care. The main purpose of this retrospective study was to determine if students who were not safe on campus have different midterm Clinical Performance Instrument (CPI) safety scores on clinical education experiences (CEEs) than students who were safe on campus. METHODS: Forty-six DPT students were categorized into two safety groups: (1) students who were not safe on campus and had successful safety remediation (n=17) and (2) students who were safe on campus (n=29). Student self-assessment (SSA) and clinical instructor (CI) midterm CPI safety scores were analyzed from 10-week CEEs (Practicum 2, 3, and 4). RESULTS: CPI data show that neither SSA nor CI midterm CPI safety scores were significantly different between safety groups for Practicum 2, 3, and 4 (p>0.05). Students who were not safe on campus had significantly higher Practicum 2 SSA midterm CPI safety scores in the majority outpatient setting (median 12.0) compared to the majority inpatient setting (median 8.5) (p=0.015). CONCLUSION: Early identification and formal remediation of safety concerns on campus can lead to suc¬cessful safety performance during CEEs.

L-edge spectroscopy of dilute, radiation-sensitive systems using a transition-edge-sensor array.

We present X-ray absorption spectroscopy and resonant inelastic X-ray scattering (RIXS) measurements on the iron L-edge of 0.5 mM aqueous ferricyanide. These measurements demonstrate the ability of high-throughput transition-edge-sensor (TES) spectrometers to access the rich soft X-ray (100-2000 eV) spectroscopy regime for dilute and radiation-sensitive samples. Our low-concentration data are in agreement with high-concentration measurements recorded by grating spectrometers. These results show that soft-X-ray RIXS spectroscopy acquired by high-throughput TES spectrometers can be used to study the local electronic structure of dilute metal-centered complexes relevant to biology, chemistry, and catalysis. In particular, TES spectrometers have a unique ability to characterize frozen solutions of radiation- and temperature-sensitive samples.

Professionalism in Physician Assistant, Physical Therapist, Occupational Therapist, Clinical Psychology, and Biomedical Sciences Students.

UNLABELLED: Interprofessional collaboration for healthcare requires a better understanding of the commonalities and differences in student perceptions of professionalism. METHODS: 217 students in five programs (PA 71, PT 46, OT 29, CP 12, and BMS 59) completed a 22-item survey (response rate 79.5%). A Likert scale grading from 1 (hardly ever) to 5 (always) was used to assess professional attitudes and behaviors. RESULTS: A mixed-model MANOVA, supplemented with post-hoc analyses, showed significant group by time interactions for 5 items. Sensitivity to differences and diversity of other people increased for BMS students, but decreased for PT students. Timeliness increased for BMS students, but did not change for PA students. Seeking out new learning experiences increased for BMS students, but did not change for PA or PT students. Taking a group leadership role increased for BMS students, decreased for PT students, while PA and OT students showed no change. Volunteering time to serve others decreased for OT and PA students, while BMS and BM students showed no change. CONCLUSION: It is plausible that these findings emerge from differences in program curricula and specific training objectives. The findings provide initial insight to educators on ways that attitudes and behaviors pertaining to professionalism sometimes vary among students in different health science programs.

A cryogenic rotation stage with a large clear aperture for the half-wave plates in the Spider instrument.

We describe the cryogenic half-wave plate rotation mechanisms built for and used in Spider, a polarization-sensitive balloon-borne telescope array that observed the cosmic microwave background at 95 GHz and 150 GHz during a stratospheric balloon flight from Antarctica in January 2015. The mechanisms operate at liquid helium temperature in flight. A three-point contact design keeps the mechanical bearings relatively small but allows for a large (305 mm) diameter clear aperture. A worm gear driven by a cryogenic stepper motor allows for precise positioning and prevents undesired rotation when the motors are depowered. A custom-built optical encoder system monitors the bearing angle to an absolute accuracy of ±0.1(∘). The system performed well in Spider during its successful 16 day flight.

Prototype phantoms for characterization of ultralow field magnetic resonance imaging.

PURPOSE: Prototype phantoms were designed, constructed, and characterized for the purpose of calibrating ultralow field magnetic resonance imaging (ULF MRI) systems. The phantoms were designed to measure spatial resolution and to quantify sensitivity to systematic variation of proton density and relaxation time, T1 . METHODS: The phantoms were characterized first with conventional magnetic resonance scanners at 1.5 and 3 T, and subsequently with a prototype ULF MRI scanner between 107 and 128 µT . RESULTS: The ULF system demonstrated a 2-mm spatial resolution and, using T1 measurements, distinguished aqueous solutions of MnCl2 differing by 20 µM [Mn(2+) ]. CONCLUSION: The prototype phantoms proved well-matched to ULF MRI applications, and allowed direct comparison of the performance of ULF and clinical systems.

Self-assessment of professionalism in physical therapy education.

OBJECTIVE: With the physical therapy (PT) professions' advancement to the clinical doctorate degree and the promotion of autonomous practice, exemplary professional conduct is an expectation of the PT profession. PT education programs are being challenged to develop methods to teach and assess professional behavior. PARTICIPANTS: Forty-three PT students (11 male and 32 female, ages 20-28 years) completed the APTA Professionalism in Physical Therapy: Core Values Self-Assessment (PPTCVSA) after their first 3 week clinical experience and again after their final clinical experience. METHODS: A mixed design ANOVA compared participants' total scores and individual Core Value scores on the Professionalism in Physical Therapy: Core Values Self-Assessment (PPTCVSA) after 3 and 33 weeks of clinical education. The effects of gender, age, and undergraduate area of study on growth in professionalism scores were also investigated. RESULTS: Total PPTCVSA scores and individual Core Value scores on professionalism (accountability, altruism, compassion/caring, excellence, integrity, professional duty, and social responsibility) were higher after 33 weeks compared to scores after 3 weeks of clinical education. Female student's total professionalism scores were higher than male student's scores on both the first and second self-assessments. In addition, female students scored themselves higher than their male peers on accountability, excellence, integrity, and professional duty. CONCLUSIONS: Improved scores on the PPTCVSA indicate that physical therapy education is playing an important role in the development of professional behavior, knowledge, and application in practice.

Evidence of galaxy cluster motions with the kinematic Sunyaev-Zel'dovich effect.

Using high-resolution microwave sky maps made by the Atacama Cosmology Telescope, we for the first time present strong evidence for motions of galaxy clusters and groups via microwave background temperature distortions due to the kinematic Sunyaev-Zel'dovich effect. Galaxy clusters are identified by their constituent luminous galaxies observed by the Baryon Oscillation Spectroscopic Survey, part of the Sloan Digital Sky Survey III. We measure the mean pairwise momentum of clusters, with a probability of the signal being due to random errors of 0.002, and the signal is consistent with the growth of cosmic structure in the standard model of cosmology.