bluuebunny/crossref_metadata_2025 huggingface dataset:
Economic Burden Associated With Management of Paradoxical Vocal Fold Motion Disorder
Authors: Lunga Tadeas , Thibeault Susan L. , Francis David O.
Published: July 2021

Objectives

Paradoxical vocal fold movement (PVFM) is often misdiagnosed as asthma and tends to have a prolonged time to diagnosis. Study aims were to estimate the time from dyspnea onset to PVFM diagnosis, to estimate associated pre‐ and postdiagnosis direct and indirect healthcare cost, and to compare the cost of postdiagnosis care among patients who did and did not undergo standard‐of‐care speech therapy.

Methods

Patients diagnosed with PVFM were identified retrospectively. Time from dyspnea symptom onset to diagnosis was measured. Direct costs consisting of office visits, procedures, and prescribed pharmaceuticals before and after diagnosis were calculated. Indirect costs associated with lost wages related to healthcare were also estimated. Costs for patients who initiated versus did not initiate speech therapy and who had successful versus unsuccessful therapy were compared.

Results

Among 110 patients, median time from dyspnea onset to PVFM diagnosis was 33 months (interquartile range [IQR] 5–60). Direct and indirect prediagnosis median costs were $8,625 (IQR $1,687–$35,812) and $736 (IQR $421–$1,579) while first year following dyspnea symptom onset median direct and indirect costs were $1,706 (IQR $427–$7,118) and $315 (IQR $131–$631). Median direct and indirect costs of care in the postdiagnosis year were $2,062 (IQR $760–$11,496) and $841 (IQR $631–$1,261). Pharmaceuticals were predominant cost drivers in all time periods. Of those who completed speech therapy, 85% had breathing symptom improvement while incurring significant cost savings compared to those whose symptoms persisted.

Conclusion

Costs of care leading to diagnosis of PVFM are substantial. More efficient methods of identifying patients with PVFM are essential to reduce prolonged time to diagnosis and associated costs.

Level of Evidence

NA Laryngoscope, 132:142–147, 2022
Initial Referring Physician and Radiologist Experience with Neck Imaging Reporting and Data System
Authors: Bunch Paul M. , Meegalla Nuwan T. , Abualruz Abdul‐Rahman , Frizzell Bart A. , Patwa Hafiz S. , Porosnicu Mercedes , Williams Daniel W. , Aiken Ashley H. , Hughes Ryan T.
Published: July 2021

Objectives/Hypothesis

Neck Imaging Reporting and Data System (NI‐RADS) is a radiology reporting system developed for head and neck cancer surveillance imaging, using standardized terminology, numeric levels of suspicion, and linked management recommendations. Through a multidisciplinary, interdepartmental quality improvement initiative, we implemented NI‐RADS for the reporting of head and neck cancer surveillance CT. Our objective is to summarize our initial experience from the standpoints of head and neck cancer providers and radiologists.

Study Design

Quality improvement study.

Methods

Before and 3 months post‐implementation, surveys were offered to referring physicians (n = 21 pre‐adoption; 22 post‐adoption) and radiologists (n = 17 pre‐ and post‐adoption). NI‐RADS utilization was assessed over time.

Results

Survey response rates were 62% (13/21) and 73% (16/22) for referring physicians pre‐ and post‐adoption, respectively, and 94% (16/17) for radiologists pre‐ and post‐adoption. Among post‐adoption provider respondents, 100% (16/16) strongly agreed or agreed with “I want our radiologists to continue using NI‐RADS,” “The NI‐RADS numerical rating of radiologic suspicion is helpful,” and “The language and style of NI‐RADS neck CT reports are clear and understandable.” Among radiologist respondents, 88% (14/16) strongly agreed or agreed with “NI‐RADS improves consistency among our radiologists in the reporting of surveillance neck CTs.” Radiologist NI‐RADS utilization increased over time (46% month 1; 72% month 3).

Conclusions

Most referring physicians and radiologists preferred NI‐RADS. Head and neck cancer providers indicated that NI‐RADS reports are clear, understandable, direct, and helpful in guiding clinical management. Radiologists indicated that NI‐RADS improves radiologist consistency in the reporting of surveillance neck CT, and radiologists increasingly used NI‐RADS over time.

Level of Evidence

4 Laryngoscope, 132:349–355, 2022
Prognostic factors after transoral resection of early hypopharyngeal cancer
Authors: Iritani Keisuke , del Mundo Daryl Anne A. , Iwaki Shinobu , Masuda Kuriko , Kanzawa Maki , Furukawa Tatsuya , Teshima Masanori , Shinomiya Hirotaka , Morimoto Koichi , Otsuki Naoki , Nibu Ken‐ichi
Published: July 2021

Objective

This study aimed to investigate risk factors predictive of local recurrence and/or lymph node metastasis after transoral resection of early hypopharyngeal cancer.

Methods

Forty‐nine consecutive patients who underwent transoral videolaryngoscopic surgery (TOVS) as an initial treatment for hypopharyngeal cancer were evaluated. On univariate and multivariate analysis, local recurrence rates were assessed respectively using log‐rank test and cox regression analysis according to the following parameters: subsite, pT, mucosal margin, lymphatic invasion, vessel invasion, tumor thickness (> 4 mm vs ≤4 mm), history of esophageal cancer, and multiple Lugol‐voiding lesions (LVLs) in the esophagus. Categorical variables were evaluated for their associations with lymph node metastasis using chi‐squared test or Fisher's exact test.

Result

The subsites of primary lesions were piriform sinus in 24 patients, posterior wall in 15 patients, and postcricoid in 10 patients. Thirty patients had esophageal cancer. Local recurrence occurred in 14 patients. Three patients had lymph node metastasis at the time of diagnosis and four patients developed lymph node metastasis after the initial treatment, resulting a total of seven patients having lymph node metastasis. While mucosal margin and LVLs showed significant associations with local recurrence on univariate analysis, only LVLs remained as a significant risk factor on multivariate analysis (P = .0395; hazard ratio = 8.897; 95% confidence interval, 1.113‐71.15). Most cases of local recurrence were satisfactorily controlled by repeated TOVS. While multivariate analysis could not be performed due to the small number of the patients with lymph node metastases, venous invasion (P = .0166) and tumor thickness (P = .0092) were significantly associated with lymph node metastasis on univariate analysis.

Conclusions

Local recurrence was more frequent in patients with LVLs, but most of them were salvaged by repeated TOVS. Patients with venous invasion and/or tumor thickness greater than 4 mm should be followed up with special attention to lymph node metastasis.

Level of Evidence: 3.
Characterization of outcomes and practices utilized in the management of internal carotid artery injury not requiring definitive endovascular management
Authors: London Nyall R. , AlQahtani Abdulaziz , Barbosa Siani , Castelnuovo Paolo , Locatelli Davide , Stamm Aldo , Cohen‐Gadol Aaron A. , Elbosraty Hussam , Casiano Roy , Morcos Jacques , Pasquini Ernesto , Frank Georgio , Mazzatenta Diego , Barkhoudarian Garni , Griffiths Chester , Kelly Daniel , Georgalas Christos , Janakiram Trichy N. , Nicolai Piero , Prevedello Daniel M. , Carrau Ricardo L.
Published: July 2021

Background

After internal carotid artery (ICA) injury during endoscopic skull base surgery, the majority of patients undergo ICA embolization or stenting to treat active extravasation or pseudoaneurysm development. However, management practices when embolization or stenting is not required have not been well described. The objective of this study was to determine how patients with ICA injury but no embolization, stenting, or ligation do long‐term and ascertain the reconstruction methods utilized.

Methods

Twenty‐nine cases of ICA injury were identified in an international multi‐institutional retrospective review. Of these, we identified six cases that were not treated with embolization, stenting, or ICA sacrifice. Information was available for five cases.

Results

A muscle patch was used in the immediate repair of each case. A nasoseptal flap was used in one case. Prefabricated nasal tampons were used in all cases. Nasal packing was initially left in for a median of 7 days prior to removal. The initial muscle patch was reinforced with a second muscle graft in one case. One case demonstrated ICA bleeding at the time of packing removal and was repacked an additional week. Follow‐up for each of these cases was at least 2 years. No cases of subsequent carotid rupture were found and none of these cases ultimately underwent endovascular stenting. Radiation or proton therapy has not been subsequently used in any of these patients.

Conclusions

This study details the reconstruction, lessons learned, and long‐term follow‐up for five cases of ICA injury not treated with embolization, stenting, or ligation.
Metamorphosis of spiny lobsters (Panulirus argusandPanulirus guttatus) in the Yucatan Current as inferred from the distribution of pueruli and final stage phyllosomata
Authors: Briones‐Fourzán Patricia , Candela Julio , Carrillo Laura , Espinosa‐Magaña Alí F. , Negrete‐Soto Fernando , Barradas‐Ortiz Cecilia , Escalante‐Mancera Edgar , Muñoz de Cote‐Hernández Rubén , Martínez‐Calderón Rogelio , Lozano‐Álvarez Enrique
Published: July 2021

For spiny lobsters (Palinuridae), the co‐occurrence of final‐stage larvae (phyllosomata) and postlarvae (pueruli) in sampling stations over oceanic waters is indicative of metamorphosis zones, some of which have been found in boundary currents. We hypothesized that metamorphosis ofPanulirus argusandP. guttatusoff the Mexican Caribbean coast, which has a very narrow shelf, occurs in the swift Yucatan Current (YC). During two cruises conducted in autumn 2012 and spring 2013, a mid‐water trawl and a neuston net were simultaneously towed in night samplings along transects up to ~ 100 km across the YC. Hydrographic and current fields were derived from Conductivity, Temperature and Depth, and altimetry data. Metamorphosis occurred mainly within the YC core. However, velocity and distance to the coast of the YC varied with cruise, and features that may favor retention (a persistent coastal eddy and a countercurrent) were detected. Despite differences in size and condition of pueruli between cruises, their energy stores did not appear to decline during the shoreward migration, suggesting that metamorphosing within strong boundary currents may increase the chances of pueruli arriving more quickly to a shore. Based on previously reported current features and swimming speeds, pueruli metamorphosing up to 12 km offshore are more likely to reach the Mexican Caribbean coast without much loss of energetic reserves. This could also occur for some pueruli metamorphosing up to 30 km offshore if encountering the features favoring retention. In contrast, pueruli metamorphosing > 30 km offshore are more likely to be carried into the Gulf of Mexico and elsewhere.
Stimulated Raman Scattering Tomography Enables Label‐Free Volumetric Deep Tissue Imaging
Authors: Gong Li , Lin Shulang , Huang Zhiwei
Published: July 2021

A novel z‐scan‐free stimulated Raman scattering tomography (SRST) is presented which is enabled by using optical beating technique (OBT) associated with Bessel beams to achieve deeper penetration for label‐free volumetric chemical imaging with subcellular resolution. In SRST, the pump beam is modulated with a spatial light modulator to convert to Bessel beam with optical beating, which is overlapped with the Bessel Stokes beam in the sample. By electronically varying the beating frequency, the depth‐resolved SRS signals about the volumetric tissue are encoded in the spatial frequency domain and thus, SRST can be rapidly retrieved by implementing inverse fast Fourier transform without a need of mechanical depth‐scan. It is demonstrated that SRST imaging using Bessel beams with self‐reconstructing properties provides at least twofold improvement in imaging depth in highly scattering polymer beads phantom as compared to conventional SRS microscopy. The capability of SRST for label‐free volumetric deeper imaging on a variety of imaging targets (e.g., Raman‐active crystals, plant cells, and biological tissue) is also proved. The generality of optical sectioning ability of Bessel beam‐OBT in SRST can be readily extended to practically any other nonlinear optical imaging modalities for deep tissue 3D imaging in biological and biomedical systems.
Cavity Optomechanical Sensing in the Nonlinear Saturation Limit
Authors: Javid Usman A. , Rogers Steven D. , Graf Austin , Lin Qiang
Published: July 2021

Photonic sensors based upon high‐quality microcavities have found a wide variety of applications ranging from inertial sensing, electro‐ and magnetometry to chemical and biological sensing. These sensors have a dynamic range limited by the linewidth of the cavity mode transducing the input. This dynamic range not only determines the range of the signal strength that can be detected, but also affects the resilience of the sensor against large deteriorating external perturbations and shocks in a practical environment. Unfortunately, there is a general trade‐off between the detection sensitivity and the dynamic range, which undermines the performance of all microcavity‐based sensors. Here, an approach is proposed to extend the dynamic range significantly beyond the cavity linewidth limit by exploiting the periodic nature of the modulation signal, making measurements in the nonlinear transduction regime without degrading the detection sensitivity for weak signals. With a cavity optomechanical system, a dynamic range of over six times larger than the cavity linewidth is experimentally demonstrated, far beyond the conventional linear region of operation for such a sensor. This approach will help design microcavity‐based sensors to achieve high detection sensitivity and a large dynamic range at the same time, a crucial property for their use in a practical environment.
Recent Progress of Layer‐by‐layer Assembly, Free‐Standing Film and Hydrogel Based on Polyelectrolytes
Authors: Ivanov Artemii S. , Pershina Lyubov V. , Nikolaev Konstantin G. , Skorb Ekaterina V.
Published: July 2021

Nowadays, polyelectrolytes play an essential role in the development of new materials. Their use allows creating new properties of materials and surfaces and vary them in a wide range. Basically, modern methods are divided into three areas—the process of layer‐by‐layer deposition, free‐standing films, and hydrogels based on polyelectrolytes. Layer‐by‐layer assembly of polyelectrolytes on various surfaces is a powerful technique. It allows giving surfaces new properties, for example, protect them from corrosion. Free‐standing films are essential tools for the design of membranes and sensors. Hydrogels based on polyelectrolytes have recently shown their applicability in electrical and materials science. The creation of new materials and components with controlled properties can be achieved using polyelectrolytes. This review focuses on new technologies that have been developed with polyelectrolytes over the last five years.
Prediction models for multiphase‐flow‐induced corrosion of API X80 steel in CO2/H2S environment
Authors: da Silva Carlos A. , Pereira Henrique B. , Taqueda Maria E. S. , Panossian Zehbour
Published: July 2021

In the offshore oil and gas industry, mainly focusing on the use of rigid or flexible pipes of subsea infrastructure applied to risers or flowlines, one of the greatest difficulties is the interpretation of the combined effects of the various correlated phenomena (hydrodynamic effects of intermittent flow, the effects of corrosivity of the environment in addition to variations in pressure, temperature, and dynamic loading). On the basis of this scenario, defining the degree of severity of each of the correlated system variables becomes of fundamental importance for establishing reliable criteria for selecting materials for subsea application. The established flow pattern directly affects the corrosion rate (or the pipe material mass loss), but the balance of other variables including possible changes in the physical and transported fluid chemical properties may increase the damage up to an order of magnitude, which is a piece of information normally not foreseen in design criteria. Therefore, to improve the understanding of the corrosion study influenced by multiphase flow, a testing loop was designed and assembled at the Corrosion and Protection Laboratory of the Institute for Technological Research, in which API X80 steel coupons were positioned in locations with a 0° and 45° inclinations. Tests were conducted by varying the partial pressure of the gaseous phase containing blends of CO2 and H2S with N2 balance, mixed with the liquid phase containing light oil and heavy oil in water with salinity (NaCl)‐simulating oil well conditions with 80% water cut. The main objective of this study is to establish models that can predict the corrosion intensity in conditions close to those obtained experimentally. To achieve results, the multiple regression and Box–Cox transformation methods were applied. These models will make possible damage prediction and optimization of matrix parameters for the multiphase‐loop test.
A comparison of methods to assess the resistance of reinforcing steel against chloride‐induced corrosion in concrete: Particular consideration of 12% chromium steel
Authors: Boschmann Käthler Carolina , Ebell Gino , Keßler Sylvia , Schiegg Yves , Dauberschmidt Christoph , Angst Ueli M.
Published: July 2021

The critical chloride content Ccrit is an indicator for the corrosion resistance of reinforcing steels in concrete. In this article, several experimental methods for determining the critical chloride content Ccrit of mild and an alloyed (12% Cr) steel in cementitious materials are compared. The methods used include accelerated polarization tests and tests using more natural (unpolarized) conditions in which chloride ingress occurs by diffusion and capillary uptake. The advantages and disadvantages of the methods are discussed, in particular, with the objective of reaching a compromise between applicability to practice and feasibility in laboratory testing.
Structure Evolution in Polyethylene‐Derived Carbon Fiber Using a Combined Electron Beam‐Stabilization‐Sulphurization Approach
Authors: Frank Erik , Muks Erna , Ota Antje , Herrmann Thomas , Hunger Michael , Buchmeiser Michael R.
Published: July 2021

A new approach is described for the production of poly(ethylene) (PE) derived carbon fibers (CFs) that entails the melt spinning of PE fibers from a suitable precursor, their cross‐linking by electron beam (EB) treatment, and sulphurization with elemental sulphur (S8), followed by pyrolysis and carbonization. Instead of focusing on mechanical properties, analysis of CF structure formation during all process steps is carried out by different techniques comprising solid‐state nuclear magnetic resonance spectroscopy, thermogravimetric analysis coupled to mass spectrometry/infrared spectroscopy, elemental analysis, energy dispersive X‐ray scattering, scanning electron microscopy, Raman spectroscopy, and wide‐angle X‐ray diffraction. A key step in structure formation is the conversion of PE into poly(thienothiophene)s during sulphurization; these species are stabile under inert gas up to 700 °C as confirmed by Raman analysis. Above this temperature, they condense into poly(napthathienophene)s, which are then converted into graphite‐type structures during pyrolysis.
Unveiling the infidelity problem in exclusive manufacturer–distributor relationships: A dyadic perspective
Authors: Leonidou Leonidas C. , Aykol Bilge , Hadjimarcou John , Palihawadana Dayananda
Published: July 2021

Infidelity has been a common dark‐side phenomenon in manufacturer–distributor (M–D) relationships, which, despite its harmful effects on operating performance and long‐term viability, has received scant theoretical and empirical attention in marketing research. Using data collected from 103 manufacturers and 101 distributors located in the USA, we investigate this phenomenon by conceptualizing it as a developmental process, comprising motives, symptoms, manifestations, consequences, and remedies. Our findings show that, with a few exceptions, there are no significant differences between manufacturers and distributors with regard to their perceptions of: (a) the structural, processual, and contextual factors contributing to the emergence of infidelity; (b) the behavioral and attitudinal factors helping to diagnose partner infidelity; (c) the ambiguous, explicit, and deceptive manifestations of infidelity; (d) the possible passive, mild, or aggressive consequences of infidelity; and (e) the pre‐emptive or post hoc measures that need to be taken to cure infidelity.
Synthesis of a Thermal‐Responsive Dual‐Modal Supramolecular Probe for Magnetic Resonance Imaging and Fluorescence Imaging
Authors: Zhou Mi , Li Li , Xie Wensheng , He Zejian , Li Jie
Published: July 2021

Dual‐modal imaging can integrate the advantages of different imaging technologies, which could improve the accuracy and efficiency of clinical diagnosis. Herein, a novel amphiphilic thermal‐responsive copolymer obtained from three types of monomers, N‐isopropyl acrylamide, 2‐(acetoacetoxy) ethyl methacrylate, and propargyl methacrylate, by RAFT copolymerization, is reported. It can be grafted with β‐cyclodextrin and aggregation‐induced emission (AIE) luminogens tetraphenylethylene by click chemistry and Biginelli reaction. The multifunctional supramolecular polymer (P4) can be constructed by host–guest inclusion between the copolymer and the Gd‐based contrast agent (CA) modified by adamantane [Ad‐(DOTA‐Gd)]. And it can form vesicles with a bilayer structure in aqueous which will enhance the AIE and magnetic resonance imaging effects. As fluorescent thermometer, P4 can enter HeLa cells for intracellular fluorescence imaging (FI) and is sensitive to temperature with detection limit value of 1.5 °C. As magnetic resonance CA, P4 exhibits higher relaxation compared to Magnevist, which can prolong the circulation time in vivo. In addition, Gd3+ in the polymer can be quickly released from the body by disassembly that reduced the biological toxicity. This work introduces new synthetic ideas for dual‐modal probe, which has great potential for clinical diagnostic applications in bioimaging.
Developing Anisotropy in Self‐Assembled Block Copolymers: Methods, Properties, and Applications
Authors: Robertson Mark , Zhou Qingya , Ye Changhuai , Qiang Zhe
Published: July 2021

Block copolymers (BCPs) self‐assembly has continually attracted interest as a means to provide bottom‐up control over nanostructures. While various methods have been demonstrated for efficiently ordering BCP nanodomains, most of them do not generically afford control of nanostructural orientation. For many applications of BCPs, such as energy storage, microelectronics, and separation membranes, alignment of nanodomains is a key requirement for enabling their practical use or enhancing materials performance. This review focuses on summarizing research progress on the development of anisotropy in BCP systems, covering a variety of topics from established aligning techniques, resultant material properties, and the associated applications. Specifically, the significance of aligning nanostructures and the anisotropic properties of BCPs is discussed and highlighted by demonstrating a few promising applications. Finally, the challenges and outlook are presented to further implement aligned BCPs into practical nanotechnological applications, where exciting opportunities exist.
Fruit and Vegetable Consumption is Inversely Associated with Plasma Saturated Fatty Acids at Baseline in Predimed Plus Trial
Authors: Domínguez‐López Inés , Marhuenda‐Muñoz María , Tresserra‐Rimbau Anna , Hernáez Álvaro , Moreno Juan José , Martínez‐González Miguel Ángel , Salas‐Salvadó Jordi , Corella Dolores , Fitó Montserrat , Martínez José Alfredo , Alonso‐Gómez Ángel M. , Wärnberg Julia , Vioque Jesús , Romaguera Dora , López‐Miranda José , Bernal‐Lopez M. Rosa , Lapetra José , Serra‐Majem J. Luís , Bueno‐Cavanillas Aurora , Tur Josep A. , Martín‐Sánchez Vicente , Pintó Xavier , Delgado‐Rodríguez Miguel , Matía‐Martín Pilar , Vidal Josep , Vázquez Clotilde , Daimiel Lidia , Serra‐Mir Mercè , Vázquez‐Ruiz Zenaida , Nishi Stephanie K. , Sorli Jose V. , Castañer Olga , Abete Itziar , Luna Jessica Vaquero , Carabaño‐Moral Rosa , Asencio Alberto , Prohens Lara , Garcia‐Rios Antonio , Casas Rosa , Gomez‐Perez Ana Maria , Santos‐Lozano José Manuel , Razquin Cristina , Martínez María Ángeles , Saiz Carmen , Robledo‐Pastor Vanesa , Zulet María Angeles , Salaverria Itziar , Eguaras Sonia , Babio Nancy , Malcampo Mireia , Ros Emilio , Estruch Ramon , López‐Sabater M. Carmen , Lamuela‐Raventós Rosa M.
Published: July 2021

Scope

Plasma fatty acids (FAs) are associated with the development of cardiovascular diseases and metabolic syndrome. The aim of our study is to assess the relationship between fruit and vegetable (F&V) consumption and plasma FAs and their subtypes.

Methods and Results

Plasma FAs are assessed in a cross‐sectional analysis of a subsample of 240 subjects from the PREDIMED‐Plus study. Participants are categorized into four groups of fruit, vegetable, and fat intake according to the food frequency questionnaire. Plasma FA analysis is performed using gas chromatography. Associations between FAs and F&V consumption are adjusted for age, sex, physical activity, body mass index (BMI), total energy intake, and alcohol consumption. Plasma saturated FAs are lower in groups with high F&V consumption (‐1.20 mg cL−1 [95% CI: [‐2.22, ‐0.18], p‐value = 0.021), especially when fat intake is high (‐1.74 mg cL−1 [95% CI: [‐3.41, ‐0.06], p‐value = 0.042). Total FAs and n‐6 polyunsaturated FAs tend to be lower in high consumers of F&V only in the high‐fat intake groups.

Conclusions

F&V consumption is associated with lower plasma saturated FAs when fat intake is high. These findings suggest that F&V consumption may have different associations with plasma FAs depending on their subtype and on the extent of fat intake.
A simplified cascade‐based de‐embedding technique for on‐wafer microwave characterization of thin‐film resistors and transmission lines
Authors: Wei Zhennan , Huang Fengyi , Tang Xusheng , Jiang Nan
Published: July 2021

A cascade‐based de‐embedding technique is presented for microwave characterization of thin‐film resistors and transmission lines. Parasitic effects of the probe pads, on‐chip interconnects and access via holes can be directly extracted using two devices under test without resorting to any additional Open/Thru dummy structures. The proposed matrix transformation provides a simplified de‐embedding methodology with a high precision similar to the conventional approaches using multiple dummy structures. The validity of the proposed technique has been demonstrated for GaN thin‐film resistors up to 65 GHz.
High‐resolution model‐based material decomposition in dual‐layer flat‐panel CBCT
Authors: Wang Wenying , Ma Yiqun , Tivnan Matthew , Li Junyuan , Gang Grace J. , Zbijewski Wojciech , Lu Minghui , Zhang Jin , Star‐Lack Josh , Colbeth Richard E. , Stayman J. Webster
Published: July 2021

Purpose

Spectral CT uses energy‐dependent measurements that enable material discrimination in addition to reconstruction of structural information. Flat‐panel detectors (FPDs) have been widely used in dedicated and interventional systems to deliver high spatial resolution, volumetric cone‐beam CT (CBCT) in compact and OR‐friendly designs. In this work, we derive a model‐based method that facilitates high‐resolution material decomposition in a spectral CBCT system equipped with a prototype dual‐layer FPD. Through high‐fidelity modeling of multilayer detector, we seek to avoid resolution loss that is present in more traditional processing and decomposition approaches.

Method

A physical model for spectral measurements in dual‐layer flat‐panel CBCT is developed including layer‐dependent differences in system geometry, spectral sensitivities, and detector blur (e.g., due to varied scintillator thicknesses). This forward model is integrated into a model‐based material decomposition (MBMD) method based on minimization of a penalized weighted least‐squared (PWLS) objective function. The noise and resolution performance of this approach was compared with traditional projection‐domain decomposition (PDD) and image‐domain decomposition (IDD) approaches as well as one‐step MBMD with lower‐fidelity models that use approximated geometry, projection interpolation, or an idealized system geometry without system blur model. Physical studies using high‐resolution three‐dimensional (3D)‐printed water‐iodine phantoms were conducted to demonstrate the high‐resolution imaging performance of the compared decomposition methods in iodine basis images and synthetic monoenergetic images.

Results

Physical experiments demonstrate that the MBMD methods incorporating an accurate geometry model can yield higher spatial resolution iodine basis images and synthetic monoenergetic images than PDD and IDD results at the same noise level. MBMD with blur modeling can further improve the spatial‐resolution compared with the decomposition results obtained with IDD, PDD, and MBMD methods with lower‐fidelity models. Using the MBMD without or with blur model can increase the absolute modulation at 1.75 lp/mm by 10% and 22% compared with IDD at the same noise level.

Conclusion

The proposed model‐based material decomposition method for a dual‐layer flat‐panel CBCT system has demonstrated an ability to extend high‐resolution performance through sophisticated detector modeling including the layer‐dependent blur. The proposed work has the potential to not only facilitate high‐resolution spectral CT in interventional and dedicated CBCT systems, but may also provide the opportunity to evaluate different flat‐panel design trade‐offs including multilayer FPDs with mismatched geometries, scintillator thicknesses, and spectral sensitivities.
Spirometry‐based reconstruction of real‐time cardiac MRI: Motion control and quantification of heart–lung interactions
Authors: Röwer Lena Maria , Uelwer Tobias , Hußmann Janina , Malik Halima , Eichinger Monika , Voit Dirk , Wielpütz Mark Oliver , Frahm Jens , Harmeling Stefan , Klee Dirk , Pillekamp Frank
Published: July 2021

Purpose

To test the feasibility of cardiac real‐time MRI in combination with retrospective gating by MR‐compatible spirometry, to improve motion control, and to allow quantification of respiratory‐induced changes during free‐breathing.

Methods

Cross‐sectional real‐time MRI (1.5T; 30 frames/s) using steady‐state free precession contrast during free‐breathing was combined with MR‐compatible spirometry in healthy adult volunteers (n = 4). Retrospective binning assigned images to classes that were defined by electrocardiogram and spirometry. Left ventricular eccentricity index as an indicator of septal position and ventricular volumes in different respiratory phases were calculated to assess heart–lung interactions.

Results

Real‐time MRI with MR‐compatible spirometry is feasible and well tolerated. Spirometry‐based binning improved motion control significantly. The end‐diastolic epicardial eccentricity index increased significantly during inspiration (1.04 ± 0.04 to 1.19 ± 0.05; P < .05). During inspiration, right ventricular end‐diastolic volume (79 ± 17 mL/m2 to 98 ± 18 mL/m2), stroke volume (41 ± 8 mL/m2 to 59 ± 11 mL/m2) and ejection fraction (53 ± 3% to 60 ± 1%) increased significantly, whereas the end‐systolic volume remained almost unchanged. Left ventricular end‐diastolic volume, left ventricular stroke volume, and left ventricular ejection fraction decreased during inspiration, whereas the left ventricular end‐systolic volume increased. The relationship between stroke volume and end‐diastolic volume (Frank‐Starling relationship) based on changes induced by respiration allowed for a slope estimate of the Frank‐Starling curve to be 0.9 to 1.1.

Conclusion

Real‐time MRI during free‐breathing combined with MR‐compatible spirometry and retrospective binning improves image stabilization, allows quantitative image analysis, and importantly, offers unique opportunities to judge heart–lung interactions.
Noninvasive assessment of steatosis and viability of cold‐stored human liver grafts by MRI
Authors: Young Liam A. J. , Ceresa Carlo D. L. , Mózes Ferenc E. , Ellis Jane , Valkovič Ladislav , Colling Richard , Coussios Constantin‐C. , Friend Peter J. , Rodgers Christopher T.
Published: July 2021

Purpose

A shortage of suitable donor livers is driving increased use of higher risk livers for transplantation. However, current biomarkers are not sensitive and specific enough to predict posttransplant liver function. This is limiting the expansion of the donor pool. Therefore, better noninvasive tests are required to determine which livers will function following implantation and hence can be safely transplanted. This study assesses the temperature sensitivity of proton density fat fraction and relaxometry parameters and examines their potential for assessment of liver function ex vivo.

Methods

Six ex vivo human livers were scanned during static cold storage following normothermic machine perfusion. Proton density fat fraction, T1, T2, andwere measured repeatedly during cooling on ice. Temperature corrections were derived from these measurements for the parameters that showed significant variation with temperature.

Results

Strong linear temperature sensitivities were observed for proton density fat fraction (R2= 0.61,P< .001) and T1(R2= 0.78,P< .001). Temperature correction according to a linear model reduced the coefficient of repeatability in these measurements by 41% and 36%, respectively. No temperature dependence was observed in T2ormeasurements. Comparing livers deemed functional and nonfunctional during normothermic machine perfusion by hemodynamic and biochemical criteria, T1differed significantly: 516 ± 50 ms for functional versus 679 ± 60 ms for nonfunctional,P= .02.

Conclusion

Temperature correction is essential for robust measurement of proton density fat fraction and T1in cold‐stored human livers. These parameters may provide a noninvasive measure of viability for transplantation.
Coherently strained and dislocation‐free architectured AlGaN/GaN submicron‐sized structures
Authors: Khalilian Maryam , Persson Axel , Lindgren David , Rosén Martin , Lenrick Filip , Colvin Jovana , Ohlsson B. Jonas , Timm Rainer , Wallenberg Reine , Samuelson Lars , Gustafsson Anders
Published: July 2021

To improve the performance and efficiency of Al containing III‐Nitride‐based devices, a number of issues must be addressed, especially the presence and generation of dislocations and other structural defects. The main sources of the dislocations are growth on non‐native substrates and heteroepitaxial growth of lattice‐mismatched layers. We demonstrate the ability to completely avoid structural defects including dislocations in AlxGa1‐xN layers with x up to 0.90 and thicknesses over 100 nm, grown directly on submicron‐sized, flat‐topped GaN platelets. These structures have an excellent homogeneity over an entire array. The GaN platelets were produced by epitaxial growth and reformation of GaN nanowires, effectively blocking the propagation of threading dislocations (TDs) from the underlying substrate. The platelets have a sufficiently small volume to elastically accommodate the strain built up in the architectured AlGaN/GaN heterostructures. Effectively, we have designed a sacrificial nano‐scaled GaN seed, with the ability to be strained by the AlGaN layer grown on top of it. The conditions for the growth of the AlGaN are chosen to avoid the creation of misfit dislocations and other structural defects. These thick and structural defect‐free, submicron‐sized AlGaN/GaN structures may open up a new path for highly efficient electronic and optoelectronic devices. These structures can be used as substrates for light‐emitting diodes and transistors, either as individual devices or arrays in parallel, depending on the need for light output or transistor current.
Working experiences of nurses during the novel coronavirus outbreak: A qualitative study explaining challenges of clinical nursing practice
Authors: Alsolami Fatmah
Published: July 2021

Aim

To explore the clinical working experiences of Saudi nurses during the novel Coronavirus outbreak, identify the challenges and determine how these challenges affect their nursing practice.

Background

From the current experience of working during the novel Coronavirus outbreak, it is statistically significant to identify the challenges that nurses in Saudi Arabia face in their clinical practice and determine how these challenges affected their practice.

Designs

A qualitative descriptive study.

Methods

An in‐depth interview with eight Registered Nurses in Saudi Arabia who worked in areas where the novel Coronavirus patients are treated were conducted between 10 and 23 April.

Results

The following eight major themes were identified from this study: physical exhaustion, fear of infection, providing care with uncertainty, uncomfortable use of personal protective equipment, missed nursing care, prolonged procedures, lack of guidance during the outbreak and lack of managerial support.

Conclusion

The results suggest that nurses’ leaders should take active roles in empowering nursing staff. The absence of direct monitoring for nursing performance during their practice compromises patient safety and jeopardises the quality of care through missed nursing care. This study also revealed that nurses who worked during the outbreak need psychological support that can enhance their emotional resilience.
Experiences and needs of home caregivers for enteral nutrition: A systematic review of qualitative research
Authors: Mou Jingjing , Sun Jianan , Zhang Rui , Yang Yang , Yang Wenwen , Zhao Xiaosu
Published: July 2021

Aims

To systematically identify, evaluate and synthesize the qualitative evidence on enteral nutrition of home caregivers.

Design

A qualitative evidence synthesis using the Sandelowski and Barroso methodology.

Data Sources

We reviewed articles from eight databases: CINAHL, Embase, PubMed, Web of Science, Cochrane, CNKI, Wanfang Data and CSTJ. Qualitative, peer‐reviewed, original studies published in English or Chinese before April 2020 on home caregivers’ experience and needs for enteral nutrition were included. The studies were selected by screening titles, abstracts and full texts, and the quality of each study was assessed by two researchers independently.

Review methods

Two researchers independently used qualitative assessment and review tools for quality assessment and thematic synthesis for data analysis.

Results

This review included 10 articles. The themes identified included balance the enteral nutrition, the experiences and feelings in practice and the recommendations to meet challenge.

Conclusion

Home caregivers reported that they played an important role and faced greater pressure. Future studies should establish a systematic and standardized follow‐up schedule to improve home caregivers’ physical and mental health.

Impact

The findings established that home caregivers experienced not only changes in their roles and concerns but also spiritual changes. Home caregivers develop different coping strategies to adapt to enteral nutrition without standardized training and support. Although home caregivers make much account of enteral nutrition and feeding issues, they lack of information and support services. Understanding existing problems from a caregiver's perspective can allow interventions to be more clearly developed and well‐established training standards established in the future.
A positivity‐preserving and energy stable scheme for a quantum diffusion equation
Authors: Huo Xiaokai , Liu Hailiang
Published: July 2021

We propose a new fully‐discretized finite difference scheme for a quantum diffusion equation, in both one and two dimensions. This is the first fully‐discretized scheme with proven positivity‐preserving and energy stable properties using only standard finite difference discretization. The difficulty in proving the positivity‐preserving property lies in the lack of a maximum principle for fourth order partial differential equations. To overcome this difficulty, we reformulate the scheme as an optimization problem based on a variational structure and use the singular nature of the energy functional near the boundary values to exclude the possibility of non‐positive solutions. The scheme is also shown to be mass conservative and consistent.
One-Step Polymerase Chain Reaction-Free Nanowire-Based Plasma Cell-Free DNA Assay to Detect EML4-ALK Fusion and to Monitor Resistance in Lung Cancer
Authors: Lee Youngjoo , Cho Youngnam , Park Eun Young , Park Seong-Yun , Hwang Kum Hui , Han Ji-Youn
Published: July 2021

Background

Next-generation sequencing has mostly been used for genotyping cell-free DNA (cfDNA) in plasma. However, this assay has several clinical limitations. We evaluated the clinical utility of a novel polymerase chain reaction–free nanowire (NW)-based plasma cfDNA assay for detecting ALK fusion and mutations.

Patients, Materials, and Methods

We consecutively enrolled 99 patients with advanced non-small cell lung cancer undergoing a fluorescence in situ hybridization (FISH) test for ALK fusion; ALK-positive (n = 36). The NW-based assay was performed using 50–100 μL of plasma collected at pretreatment and every 8 weeks during ALK inhibitor treatment.

Results

There was high concordance between the NW-based assay and the FISH test for identification of ALK fusion (94.9% with a kappa coefficient value of 0.892, 95% confidence interval [CI], 0.799–0.984). There was no difference in the response rate to the first anaplastic lymphoma kinase inhibitor between the ALK-positive patients identified by the NW-based assay and by the FISH test (73.5% vs. 72.2%, p = .931). In the ALK variant analysis, variants 1 and 3 subgroups were detected in 27 (75.0%) and 8 (22.2%) patients, respectively. Among 24 patients treated with crizotinib, variant 3 subgroup was associated with worse median overall survival than variant 1 subgroup (36.5 months; 95% CI, 0.09–87.6 vs. 19.8 months; 95% CI, 9.9–not reached, p = .004]. A serial assessment identified that ALK L1196M resistance mutation emerged before radiologic progression during crizotinib treatment.

Conclusion

The newly developed simple NW-based cfDNA assay may be clinically applicable for rapid diagnosis of ALK fusion with its variant forms and early detection of resistance.

Implications for Practice

The authors developed a novel one-step polymerase chain reaction–free nanowire (NW)-based plasma cell-free DNA (cfDNA) assay. This study evaluated the clinical utility of this novel method for the diagnosis of EML4-ALK fusion in advanced non-small cell lung cancer (NSCLC). The NW-based assay and FISH test showed high concordance rate in 99 patients with advanced NSCLC. Serial cfDNA assessment demonstrated this method provided early detection of resistance before radiologic progression during crizotinib treatment. Taken together, plasma cfDNA genotyping by the NW-based cfDNA assay may be useful for the rapid diagnosis of ALK fusion, classifying variants, and early detection of resistance.
Hypoxemic Respiratory Failure Following Ruxolitinib Discontinuation in Allogeneic Hematopoietic Cell Transplantation Recipients
Authors: Anandappa Annabelle J. , Hobbs Gabriela S. , Dey Bimalangshu R. , El-Jawahri Areej , Frigault Matthew J. , McAfee Steven L. , O'Donnell Paul V. , Spitzer Thomas R. , Chen Yi-Bin , DeFilipp Zachariah
Published: July 2021

Ruxolitinib, a selective inhibitor of Janus kinases 1 and 2, is increasingly being used in allogeneic hematopoietic cell transplantation (HCT) recipients following its approval by the U.S. Food and Drug Administration for the treatment of steroid-refractory acute graft-versus-host disease. Although there is extensive experience using ruxolitinib for patients with myeloproliferative neoplasms, the biologic effects and clinical implications of its dosing, tapering, and discontinuation for allogeneic HCT recipients are incompletely characterized. We describe three allogeneic HCT recipients who developed acute hypoxemic respiratory failure within 3 months of ruxolitinib discontinuation. Radiographic findings included marked bilateral ground-glass opacities. Systemic corticosteroids and reinitiation of ruxolitinib resulted in rapid clinical improvement in all three patients. All three patients achieved a significant clinical response, with decrease in oxygen requirement and improvement in radiographic changes. Given the increasing use of ruxolitinib in allogeneic HCT recipients, there is significant impetus to characterize the biologic and clinical effects resulting from discontinuation of ruxolitinib, to better tailor treatment plans and prevent potential adverse effects.
A comparison of fabric structures for carbon fiber reinforced composite: Laminated and orthogonal woven structures
Authors: Yang Tao , Hu Lizhu , Xiong Xiaoman , Wang Yuanfeng , Wang Xiaomeng , Petrů Michal , Zhang Shangyong , Mishra Rajesh , Militký Jiří
Published: July 2021

In this research, orthogonal structure carbon fiber reinforced composite was developed and its properties were compared with those of laminated structure composite. To solve the problem of yarn damage caused by friction during the weaving process, a custom‐built weaving device was build up. Compression and vacuum‐assisted resin infusion molding (VARIM) techniques were selected and compared. It was found that fiber geometries could be well retained using the later one. The orthogonal and laminated composites prepared by the VARIM technique with the fiber volume fraction were 32.76% and 38.64%, respectively. Flexure and impact tests were performed to evaluate the properties of laminated and orthogonal composites. The results show that orthogonal composite exhibits superior properties in the warp and weft directions. In addition, due to its straight yarn path and insertion of carbon fiber in the through‐thickness direction, orthogonal fabric reinforced composite exhibits an improved bending strength over composites reinforced by laminated plain woven fabric, although the fiber volume fraction of orthogonal composite is much lower than that of laminated composite. The findings indicate that orthogonal structure composite provides profound guiding significance for product development and application of carbon fiber composite.
Acrylonitrile‐based polymer/graphene nanocomposites: A review
Authors: George Elssa , Joy Jomon , Anas Saithalavi
Published: July 2021

Polymer composite materials fabricated from acrylonitrile‐derived polymers (such as polyacrylonitrile, nitrile butadiene rubber, styrene‐acrylonitrile, acrylonitrile butadiene styrene) with suitable fillers have found tremendous applications due to their highly desirable properties. Graphene, a versatile 2D carbon nanomaterial, with extraordinary properties has been adopted as an effective filler component of a wide range of acrylonitrile‐based polymer composites. The modified and functionalized graphene‐based nanomaterials were incorporated into the acrylonitrile‐based polymer matrix to enhance their various properties. In contrast to conventional 1D carbon nanoparticles, the incorporation of this graphene into the polymer matrix resulted excellent improvement in mechanical, electrical, rheological, and thermal, as well as frictional properties. This has offered advances in diverse applications such as sensors, flexible electronics, Li–S battery, damping, structural, microwave shielding, aircraft, spacecraft, automobile, and so forth. Particularly, the excellent EMI (Electromagnetic interference) shielding ability of these acrylonitrile‐based polymer/graphene composites has been explored widely in microelectronics. This review focuses on the recent progress and new strategies in the development of different acrylonitrile‐based polymer/graphene nanocomposites.