Carbon sp chains in diamond nanocavities.

We propose a new class of carbon allotropes obtained by combining linear sp carbon chains with sp3 bulk carbon. The structure of these crystalline carbon allotropes consists of sp chains inserted in cylindrical cavities periodically arranged in hexagonal diamond (lonsdaleite). We carry out a detailed computational analysis of the structural, electronic, and vibrational properties of a simple form in this class: a single C6 strand embedded in a nm-sized cavity. We obtain a metallic allotrope exhibiting characteristic high-frequency vibrations associated with the sp chain stretching modes, and characterized by long-time room-temperature stability. In addition, we suggest how numerous similar allotropes could be constructed within this class, that we call zayedenes, all characterized by comparable metallicity and high-frequency vibrations.

Effects of pulsed electromagnetic field therapy at different frequencies and durations on rotator cuff tendon-to-bone healing in a rat model.

BACKGROUND: Rotator cuff tears affect millions of individuals each year, often requiring surgical intervention. However, repair failure remains common. We have previously shown that pulsed electromagnetic field (PEMF) therapy improved tendon-to-bone healing in a rat rotator cuff model. The purpose of this study was to determine the influence of both PEMF frequency and exposure time on rotator cuff healing. METHODS: Two hundred ten Sprague-Dawley rats underwent acute bilateral supraspinatus injury and repair followed by either Physio-Stim PEMF or high-frequency PEMF therapy for 1, 3, or 6 hours daily. Control animals did not receive PEMF therapy. Mechanical and histologic properties were assessed at 4, 8, and 16 weeks. RESULTS: Improvements in different mechanical properties at various endpoints were identified for all treatment modalities when compared with untreated animals, regardless of PEMF frequency or duration. Of note, 1 hour of Physio-Stim treatment showed significant improvements in tendon mechanical properties across all time points, including increases in both modulus and stiffness as early as 4 weeks. Collagen organization improved for several of the treatment groups compared with controls. In addition, improvements in type I collagen and fibronectin expression were identified with PEMF treatment. An important finding was that no adverse effects were identified in any mechanical or histologic property. CONCLUSIONS: Overall, our results suggest that PEMF therapy has a positive effect on rat rotator cuff healing for each electromagnetic fundamental pulse frequency and treatment duration tested in this study.

Highly photoresponsive, ZnO nanorod-based photodetector for operation in the visible spectral range.

While significant advances have been made for gold nanoparticle (AuNP)-coupled zinc oxide (ZnO) as visibly blind, ultraviolet photodetection devices, very few ZnO nanomaterial systems have been developed specifically for use in the visible wavelength regime. Further efforts to develop ZnO-based visible photodetectors (PDs) are still highly warranted in order to better understand the precise effect of AuNP load, operation wavelength, and beam position on the device output. In this study, we demonstrate significantly enhanced, photoresponse behaviors of AuNP-coupled ZnO nanorod (NR) network devices in the visible wavelength range with their photoresponse capacity comparable to, if not far exceeding, most commercial PDs as well as recently reported, visible, AuNP-coupled ZnO detectors. In addition, the nature and degree of the photoresponsivity enhancement are systematically elucidated by investigating their light-triggered electrical signals under varying incident wavelengths, AuNP amounts, and illumination positions. We discuss a possible photoconduction mechanism of our AuNP-coupled ZnO NR PDs and the origins of the high photoresponsivity. Specifically related to the AuNP amount-dependent photoresponse behaviors, the nanoparticle density yielding photoresponse maxima is explained as the interplay between localized surface plasmon resonance, plasmonic heating, and scattering in our photothermoelectric effect-driven device. We show that the AuNP-coupled ZnO NR PDs can be constructed via a straightforward method without the need for ultrahigh vacuum, sputtering procedures, or photo/electron-beam lithographic tools. Hence, the approach demonstrated in this study may serve as a convenient and viable means to advance the current state of ZnO-based PDs for operation in the visible spectral range with greatly increased photoresponsivity.

Radio frequency-mediated local thermotherapy for destruction of pancreatic tumors using Ni-Au core-shell nanowires.

We present a novel method of radio frequency (RF)-mediated thermotherapy in tumors by remotely heating nickel (Ni)-gold (Au) core-shell nanowires (CSNWs). Ectopic pancreatic tumors were developed in nude mice to evaluate the thermotherapeutic effects on tumor progression. Tumor ablation was produced by RF-mediated thermotherapy via activation of the paramagnetic properties of the Ni-Au CSNWs. Histopathology demonstrated that heat generated by RF irradiation caused significant cellular death with pyknotic nuclei and nuclear fragmentation dispersed throughout the tumors. These preliminary results suggest that thermotherapy ablation induced via RF activation of nanowires provides a potential alternative therapy for cancer treatment.

Version Correction via Eccentric Reaming Compromises Remaining Bone Quality in B2 Glenoids: A Computational Study.

BACKGROUND: Version correction via eccentric reaming reduces clinically important retroversion in Walch type B2 glenoids (those with substantial glenoid retroversion and a second, sclerotic neoglenoid cavity) before total shoulder arthroplasty (TSA). Clinically, an increased risk of glenoid component loosening in B2 glenoids was hypothesized to be the result of compromised glenoid bone quality attributable to eccentric reaming. However, no established guidelines exist regarding how much version correction can be applied without compromising the quality of glenoid bone. QUESTIONS/PURPOSES: (1) How does version correction correlate to the reaming depth and the volume of resected bone during eccentric reaming of B2 glenoids? (2) How does version correction affect the density of the remaining glenoid bone? (3) How does version correction affect the spatial distribution of high-quality bone in the remaining glenoid? METHODS: CT scans of 25 patients identified with Walch type B2 glenoids (age, 68 ± 9 years; 14 males, 11 females) were selected from a cohort of 111 patients (age, 69 ± 10 years; 50 males, 61 females) with primary shoulder osteoarthritis who underwent TSA. Virtual TSA with version corrections of 0°, 5°, 10°, and 15° was performed on 25 CT-reconstructed three-dimensional models of B2 scapulae. After simulated eccentric reaming at each version correction angle, bone density (Hounsfield units [HUs]) was analyzed in five adjacent 1-mm layers under the reamed glenoid surface. Remaining high-quality bone (> 650 HUs) distribution in each 1-mm layer at different version corrections was observed on spatial distribution maps. RESULTS: Larger version corrections required more bone resection, especially from the anterior glenoid. Mean bone densities in the first 1-mm bone bed under the reamed surface were lower with 10° (523.3 ± 79.9 HUs) and 15° (479.5 ± 81.0 HUs) version corrections relative to 0° (0°, 609.0 ± 103.9 HUs; mean difference between 0° and 15°, 129.5 HUs [95% CI, 46.3-212.8 HUs], p < 0.001; mean difference between 0° and 10°, 85.7 HUs [95% CI, 8.6-162.9 HUs], p = 0.021) version correction. Similar results were observed for the second 1-mm bone bed. Spatial distribution maps qualitatively showed a decreased frequency of high-quality bone in the anterior glenoid as version correction increased. CONCLUSIONS: A version correction as low as 10° was shown to reduce the density of the glenoid bone bed for TSA glenoid fixation in our computational study that simulated reaming on CT-reconstructed B2 glenoid models. Increased version correction resulted in gradual depletion of high-quality bone from the anterior region of B2 glenoids. CLINICAL RELEVANCE: This computational study of eccentric reaming of the glenoid before TSA quantitatively showed glenoid bone quality is sensitive to version correction via simulated eccentric reaming. The bone density results of our study may benefit surgeons to better plan TSA on B2 glenoids needing durable bone support, and help to clarify goals for development of precision surgical tools.

Epidemiology of Herpes Zoster Ophthalmicus: Recurrence and Chronicity.

PURPOSE: A hospital-based epidemiology study to describe herpes zoster ophthalmicus (HZO) prevalence and risk factors for recurrent and chronic disease. DESIGN: Retrospective, hospital-based cohort study. PARTICIPANTS: All patients evaluated in the Broward and Miami Veterans Administration Healthcare System (MIAVHS) during the study period. METHODS: Retrospective medical record review of patients seen in the MIAVHS from January 1, 2010, through December 31, 2014, with a HZO clinical diagnosis. Assessment of the patient's clinical course was defined by the following: an acute episode of HZO was defined as quiescence of disease within 90 days of initial presentation, HZO recurrence was defined as any recurrent eye disease or rash 90 days or more after quiescence of disease was noted off therapy, and chronic HZO was defined as active disease persisting more than 90 days from initial presentation. MAIN OUTCOME MEASURES: Main outcome measures included the frequency of HZO with and without eye involvement, HZO recurrence rates, and risk factors for recurrent or chronic HZO. RESULTS: Ninety patients with HZO were included in the study. The mean age at incident episode of HZO was 68±13.8 years (range, 27-95 years). Most patients were white (73%), immune competent (79%), and did not receive zoster vaccination at any point during the follow-up (82%). Patients were followed for a mean of 3.9±5.9 years (range, 0-33 years). The period prevalence of HZ in any dermatome was 1.1%, the frequency of HZ involving V1 (HZO) was 0.07%, and the frequency of HZO with eye involvement was 0.05%. The overall 1-, 3-, and 5-year recurrence rates for either recurrent eye disease or rash were 8%, 17%, and 25%, respectively. Ocular hypertension (hazard ratio [HR], 4.6; 95% confidence interval [CI], 1.3-16.5; odds ratio [OR], 6.7; 95% CI, 1.5-31.2) and uveitis (HR, 5.7; 95% CI, 1.7-19.0; OR, 6.7; 95% CI, 1.5-31.2) increased the risk of recurrent and chronic disease. CONCLUSIONS: This study supports newer data indicating that a significant proportion of patients experience recurrent and chronic HZO. Further study is needed to guide preventative and therapeutic approaches to recurrent and chronic HZO.

Outcomes of Custom Flange Acetabular Components in Revision Total Hip Arthroplasty and Predictors of Failure.

BACKGROUND: Custom triflange acetabular components (CTAC) have become more popular in the treatment of Paprosky type IIIB defects with an average survivorship of 80% at 4 years. Many studies report survivorship of CTAC, but radiographic parameters of CTAC success or failure have not been previously reported. The purpose of the study was to assess radiographic and patient factors predictive of failure in CTAC. METHODS: A retrospective review of 63 patients with >24 months of follow-up was completed. Continuous and categorical variables were compared between failed vs successful CTAC using Wilcoxon rank-sum test and Fisher exact test, respectively. RESULTS: The failure rate of the CTAC was 13.5% over an average follow-up of 4.32 years (±2.94). Patients had a mean of 2 revisions (range, 0-11) before CTAC implantation. Compared with the contralateral hip center of rotation, the failed CTAC group tended to lateralize the hip center by a mean of 18.29 mm (±11.90 mm) compared to a mean of 9.86 mm (±11.89) in the intact group, although this did not reach statistical significance (P = .1029). The Western Ontario and McMaster Universities Osteoarthritis Index function score improved from 38.94 (±14.23) to 71.35 (±21.96) at most recent follow-up (P = .0002). The Western Ontario and MacMaster Universities Osteoarthritis Index scores were not significantly different between intact and failed CTAC groups. CONCLUSIONS: CTAC tends to lateralize the hip center by approximately 1 cm, and there is a trend toward nearly 2 cm of lateralization in the small subset of failed CTAC. Future efforts should focus on medializing the hip center in CTAC to improve ingrowth and survivorship.

The effects of progressive lateralization of the joint center of rotation of reverse total shoulder implants.

BACKGROUND: There has been a renewed interest in lateralizing the center of rotation (CoR) in implants used in reverse shoulder arthroplasty. The aim of this study was to determine the sensitivity of lateralization of the CoR on the glenohumeral joint contact forces, muscle moment arms, torque across the bone-implant interface, and the stability of the implant. METHODS: A 3-dimensional virtual model was used to investigate how lateralization affects deltoid muscle moment arm and glenohumeral joint contact forces. This model was virtually implanted with 5 progressively lateralized reverse shoulder prostheses. The joint contact loads and deltoid moment arms were calculated for each lateralization over the course of 3 simulated standard humerothoracic motions. RESULTS: Lateralization of the CoR leads to an increase in the overall joint contact forces across the glenosphere. Most of this increased loading occurred through compression, although increases in anterior/posterior and superior/inferior shear were also observed. Moment arms of the deltoid consistently decreased with lateralization. Bending moments at the implant interface increased with lateralization. Progressive lateralization resulted in improved stability ratios. CONCLUSIONS: Lateralization results in increased joint loading. Most of that loading occurs through compression, although there were also increases in shear forces. Anterior/posterior shear is currently not accounted for in implant fixation studies, leaving its effect on implant fixation unknown. Future studies should incorporate shear forces into their models to more accurately assess fixation methods.

Functional consequences of T-stem mutations in E. coli tRNAThrUGU in vitro and in vivo.

The binding affinities between Escherichia coli EF-Tu and 34 single and double base-pair changes in the T stem of E. coli tRNA(Thr)(UGU) were compared with similar data obtained previously for several aa-tRNAs binding to Thermus thermophilus EF-Tu. With a single exception, the two proteins bound to mutations in three T-stem base pairs in a quantitatively identical manner. However, tRNA(Thr) differs from other tRNAs by also using its rare A52-C62 pair as a negative specificity determinant. Using a plasmid-based tRNA gene replacement strategy, we show that many of the tRNA(Thr)(UGU) T-stem changes are either unable to support growth of E. coli or are less effective than the wild-type sequence. Since the inviable T-stem sequences are often present in other E. coli tRNAs, it appears that T-stem sequences in each tRNA body have evolved to optimize function in a different way. Although mutations of tRNA(Thr) can substantially increase or decrease its affinity to EF-Tu, the observed affinities do not correlate with the growth phenotype of the mutations in any simple way. This may either reflect the different conditions used in the two assays or indicate that the T-stem mutants affect another step in the translation mechanism.

Materials Innovations for Quantum Technology Acceleration: A Perspective.

A broad perspective of quantum technology state of the art is provided and critical stumbling blocks for quantum technology development are identified. Innovations in demonstrating and understanding electron entanglement phenomena using bulk and low-dimensional materials and structures are summarized. Correlated photon-pair generation via processes such as nonlinear optics is discussed. Application of qubits to current and future high-impact quantum technology development is presented. Approaches for realizing unique qubit features for large-scale encrypted communication, sensing, computing, and other technologies are still evolving; thus, materials innovation is crucially important. A perspective on materials modeling approaches for quantum technology acceleration that incorporate physics-based AI/ML, integrated with quantum metrology is discussed.

Handheld Lung Ultrasound to Detect COVID-19 Pneumonia in Inpatients: A Prospective Cohort Study.

Background: Chest imaging, including chest X-ray (CXR) and computed tomography (CT), can be a helpful adjunct to nucleic acid test (NAT) in the diagnosis and management of Coronavirus Disease 2019 (COVID-19). Lung point of care ultrasound (POCUS), particularly with handheld devices, is an imaging alternative that is rapid, highly portable, and more accessible in low-resource settings. A standardized POCUS scanning protocol has been proposed to assess the severity of COVID-19 pneumonia, but it has not been sufficiently validated to assess diagnostic accuracy for COVID-19 pneumonia. Purpose: To assess the diagnostic performance of a standardized lung POCUS protocol using a handheld POCUS device to detect patients with either a positive NAT or a COVID-19-typical pattern on CT scan. Methods: Adult inpatients with confirmed or suspected COVID-19 and a recent CT were recruited from April to July 2020. Twelve lung zones were scanned with a handheld POCUS machine. Images were reviewed independently by blinded experts and scored according to the proposed protocol. Patients were divided into low, intermediate, and high suspicion based on their POCUS score. Results: Of 79 subjects, 26.6% had a positive NAT and 31.6% had a typical CT pattern. The receiver operator curve for POCUS had an area under the curve (AUC) of 0.787 for positive NAT and 0.820 for a typical CT. Using a two-point cutoff system, POCUS had a sensitivity of 0.90 and 1.00 compared to NAT and typical CT pattern, respectively, at the lower cutoff; it had a specificity of 0.90 and 0.89 compared to NAT and typical CT pattern at the higher cutoff, respectively. Conclusions: The proposed lung POCUS protocol with a handheld device showed reasonable diagnostic performance to detect inpatients with a positive NAT or typical CT pattern for COVID-19. Particularly in low-resource settings, POCUS with handheld devices may serve as a helpful adjunct for persons under investigation for COVID-19 pneumonia.

Fabrication and characterization of RF nanoantenna on a nanoliter-scale 3D microcontainer.

We report the design and fabrication of a nanoantenna structure on the surface of a 3D nanoliter-scale container for the development of communicable nanoliter-scale chemical delivery systems. The porous container was self-assembled, after which the nanoantenna was fabricated on the top of the microcontainer using focused ion beam (FIB) ion-induced metal deposition. The nanoantenna was structured as a rectangular metal coil composed of platinum (Pt) nanowires (70 nm in width). The response of the nanoantenna structure was simulated using finite element software and showed a strong resonant feature at 10.8 GHz, which was confirmed by high frequency measurements.

Development and validation of a novel prediction score for cardiac tamponade in emergency department patients with pericardial effusion.

AIMS: Determining which patients with pericardial effusion require urgent intervention can be challenging. We sought to develop a novel, simple risk prediction score for patients with pericardial effusion. METHODS AND RESULTS: Adult patients admitted through the emergency department (ED) with pericardial effusion were retrospectively evaluated. The overall cohort was divided into a derivation and validation cohort for the generation and validation of a novel risk score using logistic regression. The primary outcome was a pericardial drainage procedure or death attributed to cardiac tamponade within 24 h of ED arrival. Among 195 eligible patients, 102 (52%) experienced the primary outcome. Four variables were selected for the novel score: systolic blood pressure < 100 mmHg (1.5 points), effusion diameter [1-2 cm (0 points), 2-3 cm (1.5 points), >3 cm (2 points)], right ventricular diastolic collapse (2 points), and mitral inflow velocity variation > 25% (1 point). The need for pericardial drainage within 24 h was stratified as low (<2 points), intermediate (2-4 points), or high (≥4 points), which corresponded to risks of 8.1% [95% confidence interval (CI) 3.0-16.8%], 63.8% [95% CI 50.1-76.0%], and 93.7% [95% CI 84.5-98.2%]. The area under the curve of the simplified score was 0.94 for the derivation and 0.91 for the validation cohort. CONCLUSION: Among ED patients with pericardial effusion, a four-variable prediction score consisting of systolic blood pressure, effusion diameter, right ventricular collapse, and mitral inflow velocity variation can accurately predict the need for urgent pericardial drainage. Prospective validation of this novel score is warranted.

Nanoleite: a new semiconducting carbon allotrope predicted by density functional theory.

In this report, a new carbon allotrope named nanoleite is proposed. Its crystal structure is constructed by embedding carbon nanotubes into the matrix of lonsdaleite periodically, leading to a hexagonal primitive unit cell. The equilibrium structure of nanoleite is fully relaxed by density functional theory calculation, and we demonstrate that nanoleite is a semiconductor with an indirect energy bandgap of 2.06 eV. Furthermore, it has a high absorption coefficient in the visible spectrum range, which is comparable to that of the gallium arsenide and indium phosphide. X-ray diffraction patterns and phonon modes are also studied.