bluuebunny/crossref_metadata_2025 huggingface dataset:
Reverse supply chain conceptual model for construction and demolition waste
Authors: Brandão Rayra , Edwards David J , Hosseini M Reza , Silva Melo André Cristiano , Macêdo Alcebiades Negrão
Published: March 2021

Construction and demolition waste (CDW) substantially contributes to environmental degradation because of its intrinsic characteristics of fast and high generation volume, low recycling rate, and low revenue margins. A systemic problem is that recycling facilities are not usually a part of a reverse supply chain (RSC) specific for CDW. This makes the recovery process costs prohibitive, especially where companies are unable to receive and process large volumes of waste continuously. This paper presents a systematic analysis of the extant literature and utilizes the results accrued to develop a conceptual RSC model for CDW. In so doing, the research seeks to provide clarity on this phenomenon, while simultaneously stimulating wider academic discourse and further research endeavours. A mixed philosophies epistemological design was adopted using both interpretavism and constructivism to undertake a qualitative systematic analysis of the literature. A process diagram was produced to represent the conceptual model (CM) and thematically group the nodes into three key swim lanes that delineate the boundaries between distribution, manufacturing, and sourcing and warehousing processes. Within each swim lane, stakeholders were incorporated as key actors. A further layer of nuanced complexity was added to illustrate the key actors involved in the process, government strategies, and activity flow paths. This novel CM offers both practical and theoretical contributions to existing knowledge and signposts a future research direction. Such work will demystify reverse logistics for managing CDW, and assist government policy-makers to develop informed policies that reduce the negative environmental impact of construction activities.
The “Structurally Adjusted” School: A Case from New York
Authors: Michaels Erin
Published: March 2021

This article argues that U.S. education reforms for “failing” schools are strikingly similar to a domestic Structural Adjustment Program; and that comparing the two clarifies: how K–12 schools are neoliberalized and how neoliberalism’s key feature is the making of a larger yet less democratic state. The study contrasts with the scholarship claiming that reforms epitomized by the “No Child Left Behind Act” are neoliberal because they stem from interests in privatization for capital accumulation. The analysis focuses on a “failing” school navigating federal reforms in New York State, drawing on education policy, school documents, ethnography, and interviews. It shows how the neoliberal state took power from local school authorities, and largely did not shrink the state via privatization. This work illustrates how neoliberal reforms for “failing” schools are at least as much about power as they are about profits and demonstrates the large-scale continuity in neoliberal restructuring strategies and outcomes.
L1 neural network adaptive fault-tolerant controller for unmanned aerial vehicle attitude control system
Authors: Zhou Yan , Liu Huiying , Guo Huijuan , Li Jing
Published: March 2021

In this article, a L1 neural network adaptive fault-tolerant controller is exploited for an unmanned aerial vehicle attitude control system in presence of nonlinear uncertainties, such as system uncertainties, external disturbances, and actuator faults. A nonlinear dynamic inversion controller with sliding mode control law is designed as the outer-loop controller to track the attitude angles quickly and accurately which reduces dependence on model accuracy. A L1 neural network adaptive controller of the inner loop is introduced to compensate the nonlinear uncertainties and have a good attitude tracking. The radial basis function neural network technique is introduced to approximate a lumped nonlinear uncertainty and guarantee the stability and transient performance of the closed-loop system, instead of converting it to a half-time linear system by the parametric linearization method. Simulation results demonstrate the effectiveness of the proposed controller.
Early fault detection of gas turbine hot components under different ambient and operating conditions
Authors: Liu Jiao , Liu Jinfu , Yu Daren , Wang Zhongqi , Yan Weizhong , Pecht Michael
Published: March 2021

Failure of hot components in gas turbines often causes catastrophic results. Early fault detection can prevent serious incidents and improve the availability. A novel early fault detection method of hot components is proposed in this article. Exhaust gas temperature is usually used as the indicator to detect the fault in the hot components, which is measured by several exhaust thermocouples with uniform distribution at the turbine exhaust section. The healthy hot components cause uniform exhaust gas temperature (EGT) profile, whereas the hot component faults could cause the uneven EGT profile. However, the temperature differences between different thermocouple readings are also affected by different ambient and operating conditions, and it sometimes has a greater influence on EGT than the faults. In this article, an accurate EGT model is presented to eliminate the influence of different ambient and operating conditions on EGT. Especially, the EGT profile swirl under different ambient and operating conditions is also included by considering the information of the thermocouples’ spatial correlations and the EGT profile swirl angle. Based on the developed EGT model, the detection performance of early fault detection of hot components in gas turbine is improved. The accuracy and effectiveness of the developed early fault detection method are evaluated by the real-world gas turbine data.
Improvement of structural characteristics of composite thin-walled beams using variable stiffness concept via curvilinear fiber placement
Authors: Farsadi Touraj , Bozkurt Mirac Onur , Coker Demirkan , Kayran Altan
Published: March 2021

This study presents the use of variable stiffness concept via curvilinear fiber placement to achieve improved structural characteristics in composite thin-walled beams (TWBs). The TWB used in the study is constructed in circumferentially asymmetric stiffness (CAS) configuration. The variation of fiber angles along the span and the width of the TWB is included by defining two fiber path functions. A parametric study is performed to investigate the effects of different fiber paths on the structural performance metrics including frequency spacing, unit twist, and critical buckling load. For this purpose, a semi-analytical solution method is developed to conduct free vibration, deformation, and buckling analyses of the TWB with curvilinear fibers. The semi-analytical method is validated with several finite element (FE) analyses performed using ABAQUS. Elastic stress analyses of TWBs with selected fiber paths subjected to simplified distributed loading are also conducted using the FE method, and a ply failure criterion is applied to evaluate the strength of these TWBs. Overall results show that curvilinear fiber placement varied along the span leads to greater structural performance for a composite TWB than the straight fiber configuration.
Fault-tolerant control allocation of a flexible satellite with an infinite-dimensional model
Authors: Ashayeri Leila , Doustmohammadi Ali , Fani Saberi Farhad
Published: March 2021

Fault-tolerant control allocation (FTCA) strategy is proposed for attitude stabilization of a flexible satellite with actuator redundancy. The control scheme is based on the infinite-dimensional model of a flexible satellite with no discretization, so the spillover instability is eliminated. This is one of the important benefits of the proposed control scheme over the previous FTCA schemes that have been used for the flexible satellite. The proposed scheme contains two modules. The first module provides a virtual control law to meet stabilization and vibration control objectives in the presence of uncertainties and external disturbances. There is no need to implement in-domain actuators on panels to stabilize their vibration. In this module, the virtual control is designed using adaptive integral sliding mode approach where the sliding surface includes angular velocities, internal reaction torques, and nominal control for healthy system. The second module, based on fault/failure information and using a control allocation scheme, provides redistribution of the virtual control law among the available actuators. Due to simultaneous actuator faults and control constraints, there is an error between the actual virtual control and the designed control that affects the overall system stability. To eliminate this error, gain of the virtual control signal is adjusted by an adaptive updating law. The closed-loop system stability is guaranteed for small changes in a neighborhood of the sliding surface with simultaneous vibration damping. A numerical example illustrates the effectiveness of the proposed control strategy.
Oxygen concentration distribution in a pulse detonation engine with nozzle–ejector combinational structures
Authors: Wang Zhiwu , Wei Lisi , Qin Weifeng , Liang Zijian , Zhang Kun
Published: March 2021

Pulse detonation engines (PDEs) with three different types of nozzle–straight ejector combinational structures at three different ejector positions were simulated by the unsteady 2-D axisymmetric method to understand the influence of nozzle–ejector combinational structures on the performance of PDEs. Three types of nozzles included the straight nozzle, convergent nozzle, and convergent–divergent (CD) nozzle. Three ejector positions were considered according to the ratio of the distance between the nozzle outlet and the ejector inlet to the diameter of PDEs (Δx/d). Propane was used as the fuel and air as the oxidizer. The simulation results indicated that for the PDE with the straight nozzle, it took the shortest time for high-temperature burnt gas to exhaust from the detonation tube. For the PDE with the CD nozzle, the time at which the ejector was filled with external air was the fastest. Within the time range of t = 0–10 ms, the ejected air was less than the original air in the ejector among all the nine combinational structures. The maximum ejected air was obtained with the convergent nozzle, followed by the CD nozzle, and the minimum with the straight nozzle. For certain nozzles, the maximum air was ejected at the ejector position of Δx/d = +1, followed by the ejector position of Δx/d = 0, and the minimum at the ejector position of Δx/d = −1. For the convergent nozzle–ejector combinational structure, the air ejection speed was the fastest. Oxygen concentration distribution in the PDE with the CD nozzle was more uniform along the axial direction than the other nozzles.
Pressure measurements in detonation engines
Authors: Ivanov Vladislav S , Frolov Sergei M , Sergeev Sergei S , Mironov Yurii M , Novikov Andrei E , Schultz Iliya I
Published: March 2021

The influence of waveguide tubes on the signals received by remote pressure sensors measuring pressure histories in pulsed detonation engines (PDEs) and rotating detonation engines (RDEs) is studied computationally. Two types of pressure sensors are considered: low-frequency static pressure sensors and high-frequency sensors of pressure pulsations. Three approaches to solving the problem are used: based on Euler (inviscid flow), Navier–Stokes (laminar flow), and unsteady Reynolds-averaged Navier–Stokes (turbulent flow) equations. The approaches based on the inviscid and laminar flow models are shown to provide the best predictive capability. The laminar flow model is applied to analyzing the readings of pressure sensors installed remotely in the waveguide tubes attached to the hydrogen-fueled PDE, RDE, and detonation ramjet (DR). It is shown that the measurements of static pressure and pressure pulsations by remote pressure sensors do not correspond to the time-averaged mean and local instantaneous values of pressure in the combustors. The pressure time histories can be recovered based on the measurements and computational fluid dynamics calculations of the operation process. The latter is demonstrated by analyzing the results of test fires with a dual-duct DR model.
Spacecraft attitude determination using electrostatically suspended gyroscope with rotating rings
Authors: Ghanbarpourasl Habib
Published: March 2021

This article presents a novel method for satellite attitude determination, using two electrostatically suspended gyroscopes (ESGs). In this method, two superconducting rings (like gimbals) rotated around each suspended spherical rotor, which causes a variable flux in the rings. A voltage will be induced in the rings according to Faraday’s law of induction. Satellite attitude is determined by integrating of the induced voltages and strap-down rate gyros using the extended Kalman filter. This gyroscope works precisely when the rotor is maintained at the center of the gyroscope cavity, between three pairs of the circular electrodes, and then a backstepping control algorithm is designed for this purpose. The performance of attitude determination using such sensor and designed control algorithm is evaluated by six-degree-of-freedom simulation of a satellite in the MATLAB software. The simulations show the proposed algorithm works in an excellent manner and has lower than a few hundred arc second errors. The accurately aligning of rotors in the known direction to space is essential and is another problem that we do not address here.
Investigation of bone fracture diagnosis system using transverse vibration response
Authors: Yoon Gil Ho , Woo Yeon-Jun , Sim Seong-Gyu , Kim Dong-Yoon , Hwang Se Jin
Published: March 2021

In this study, a new diagnostic system is developed to easily identify bone fractures in non-medical environments. It is difficult to determine the extent of cracks, fractures, and the healing process inside humans owing to the differences among people and limitations of state-of-the-art medical devices. Thus, various medical techniques, such as X-ray, computed tomography, or fork tuning systems have been developed, and more advanced technologies are emerging in the medical engineering field. In hazardous circumstances, medical devices to detect bone fracture are not available or cannot be easily applied. Thus, there is a need for the rapid detection of bone fractures without medical devices. To this end, this study analyzes the transverse vibration responses of bones because bone fractures cause different mechanical vibration reactions. By comparing the transverse vibration responses of both healthy and fractured bones, the modal assurance criterion can be calculated and applied to detect the existence of bone fractures. The transverse vibration responses at low and high frequencies are different and exhibit different modal assurance criteria depending on whether or not they are abnormal. Then, the virtual spectrogram of the differences between the signals from non-fractured and fractured bones is calculated. With the help of the present criterion with transverse vibration data, this difference can be analyzed quantitatively and effectively. To validate the proposed system, experiments with artificial specimens, animal legs, and a cadaver are performed.
Teacher beliefs about instructional approaches: Interrogating the notion of teaching methods
Authors: Wesely Pamela M. , Vyn Reuben , Neubauer Diane
Published: March 2021

World language teachers have historically relied on the notion of teaching methods to inform elements of design and procedure in their instructional practice. Teacher beliefs about teaching methods, however, have been shown to be significantly influenced by their context, including their institution and their learners. This phenomenon has led some scholars to identify a postmethod condition, where teachers prioritize making responsive, principled decisions about instruction based on their context. This qualitative study investigated the patterns and realities of the postmethod condition in practice through the lens of teacher beliefs about teaching methods, focusing on ten secondary-level world language teachers of French and Spanish in the USA. Data sources included a survey about teaching methods, in-depth interviews, and classroom observations. Data analysis included descriptive statistics, multiple phases of coding, and integrating analysis of the three sources. Findings indicated that teachers in this group largely identified as adhering to one main teaching approach, with eight of the ten self-identifying as using primarily comprehensible input and/or TPRS (Teaching Proficiency through Reading and Storytelling) methods. However, through investigating their beliefs about grammar and accuracy; the four skills of reading, writing, listening, and speaking; the importance of input and output; and instructional flow, we found that the teachers examined and reexamined their teaching methods regularly, largely due to the influences of their learners and their institution. The relationship between the teachers’ beliefs and practices was mediated by context-driven instructional decision-making, indicating the presence of a postmethod condition.
Referencing word and phrase lists in an online vocabulary notebook
Authors: Carney Nathaniel
Published: March 2021

The current study investigated 29 first-year Japanese university students’ usage of an online vocabulary notebook that automatically searched eight different word and phrase lists to provide students with reference information about their self-selected vocabulary. Over the course of a 14-week period, participants read English books and articles and added self-selected vocabulary that they wanted to learn to individual online vocabulary notebooks. The notebooks immediately and automatically showed whether the vocabulary appeared on any of eight different reference vocabulary lists. The distribution of participant vocabulary across lists was examined and participant surveys and interviews were conducted to understand usage of the system. Analysis of participant vocabulary, learner surveys, and interviews indicated that participants selected relatively high percentages of standardized-test related vocabulary (i.e. TOEIC and TOEFL), chose individual vocabulary items over multi-word expressions, and studied vocabulary items even when they did not appear on any reference lists. Learner surveys and interview results suggested that use of the system directly or indirectly influenced half of the participants’ decisions about which vocabulary to include in their notebooks, though participants reported that it did not affect their choice of reading material.
‘Having to use English others us': South African terminologies of sexual and gender diversity
Authors: Lynch Ingrid , Reygan Finn , Ramphalile Molemo
Published: March 2021

The linguistic coding of sexual and gender diversity remains highly contested in African contexts. While English language terminologies reflecting rights-based talk proliferate, such terms fail to fully reflect the lived realities of African queerness. This paper engages existing South African research on indigenous terminologies to describe sexual and gender diversity, focusing on representations of male same-sex sexualities. Our findings show that local terminologies serve not only to ‘other’ sexual and gender diversity, but also hold the potential to render those existing outside of normative sex/gender binaries as socially intelligible. Two core themes emerged: (i) the persistence of heterogendered subjectivities, where sexual dissidence is mapped onto a normative male/female binary; and (ii) a procreative imperative focused on communitarian norms that privilege heterosexual childbearing. The findings highlight the limitations of global terminologies of sexual and gender diversity by engaging the ways in which local African terminologies provide social recognition for same-sex sexualities in generally heteronormative community spaces. We discuss the implications of this gendered encoding of sexual dissidence in terms of advocacy strategies for the greater social inclusion of sexual and gender minorities.
Physician experiences of screen-level features in a prominent electronic health record: Design recommendations from a qualitative study
Authors: Khairat Saif , Coleman Cameron , Teal Randall , Rezk Salma , Rand Victoria , Bice Thomas , Carson Shannon S
Published: March 2021

The goal of this qualitative study was to assess physicians’ perceptions around features of key screens within a prominent commercial EHR, and to solicit end-user recommendations for improved retrieval of high-priority clinical information. We conducted a qualitative, descriptive study of 25 physicians in a medical ICU setting. at a tertiary academic medical center. An in-depth, semi-structured interview guide was developed to elicit physician perceptions on information retrieval as well as favorable and unfavorable features of specific EHR screens. Transcripts were independently coded in a qualitative software management tool by at least two trained coders using a common code book. We successfully obtained vendor permission to map physicians perception’s on full Epic© screenshots. Among the 25 physician participants (13 female; 5 attending physicians, 9 fellows, 11 residents), the majority of participants reported experiencing challenges finding clinical information in the EHR. We present the most favorable and unfavorable screen-level features for four central EHR screens: Flowsheet, Notes/Chart Review, Results Review, and Vital Signs. We also compiled participants’ recommendations for a comprehensive EHR dashboard screen to better support clinical workflow and information retrieval in the medical ICU through User-Centered Design. ICU physicians demonstrated a mix of positive and negative attitudes toward specific screen-level features in a major vendor-based EHR system. Physician perceptions of information overload emerged as a theme across multiple EHR screens. Our findings underscore the importance of qualitative research and end-user feedback in EHR software design and interface optimization at both the vendor and institutional level.
Hybrid Repair of a Common Carotid Pseudoaneurysm and Concomitant Internal Carotid Stenosis With Retrograde Stenting and Carotid Endarterectomy
Authors: Zarmakoupis Constantinos , Galyfos George , Tsoukalos Grigorios , Dalla Panagiota , Triantafyllou Alexandra , Zografos Konstantinos , Sigala Fragiska , Filis Konstantinos
Published: March 2021

This report aims to present a rare case of a common carotid artery (CCA) pseudoaneurysm with a concomitant internal carotid artery (ICA) stenosis that were treated with a hybrid technique. This strategy included the retrograde placement of a CCA covered stent under ICA clamping followed by standardized carotid endarterectomy. The technique will be discussed and compared with other possible treatments.
What are the most common reasons for return of ethics submissions? An audit of an Australian health service ethics committee
Authors: Brandenburg Caitlin , Thorning Sarah , Ruthenberg Carine
Published: March 2021

One of the key criticisms of the ethical review process is the time taken to decision, and associated resource use. A key source of delay is that most submissions are required to respond to at least one request for further information or clarification from the Human Research Ethics Committee (HREC). This study audited the request letters of a single Australian public health HREC using content analysis. Twenty-four submissions were analysed, including 355 individual request elements. Most submissions received a single request letter. There was a mean number of 14.2 (SD = 5.5) elements per letter for the first request and a mean of 2.1 (SD = 1.2) for subsequent requests. Administrative errors were the most common source of request for further information, occurring in all submissions. The second most common theme was the content of the Participant Information and Consent Form, occurring in 79% of submissions. Other common themes, present in over 50% of submissions, concerned: data collection and study procedures; general ethical considerations; recruitment and consent; site, setting or patient pool; research design and methodology; and data management and security. In terms of the general purpose of the HREC comments, 44% were direct corrections or specific requests for changes, 42% were asking for more information or clarification of existing information, and 14% were the HREC expressing concerns about an element of the study, without directly suggesting a change. Overall, the study provides some evidence to show that the quality of the submission (ensuring correct attachments, up to date documents, clear information etc.) could account for a significant proportion of the burden and delay associated with ethical review.
A meta-analysis of aspirin and subarachnoid hemorrhage in patients with intracranial aneurysms yields different results to the general population
Authors: Ewbank Frederick , Birks Jacqueline , Bulters Diederik
Published: March 2021

Background

Some studies have shown a protective association between aspirin use and subarachnoid hemorrhage. Other studies have found no relationship or the reverse. These studies differ in their study populations and definitions of subarachnoid hemorrhage.

Aims

Our aim was to establish (1) if there is an association between aspirin and subarachnoid hemorrhage, (2) how this differs between the general population and those with intracranial aneurysms.

Summary of review

Studies reporting aspirin use and the occurrence of subarachnoid hemorrhage were included and grouped based on population (general population vs. aneurysm population). Odds ratios, hazard ratios, and confidence intervals were combined in random-effects models. Eleven studies were included. Overall, there was an association between aspirin and subarachnoid hemorrhage (OR 0.68 [0.48, 0.96]). However, populations were diverse and heterogeneity between studies high ( p < 0.00001), questioning the validity of combining these studies and justifying analysis by population. In the general population, there was no difference in aspirin use between individuals with and without subarachnoid hemorrhage (OR 1.15 [0.96, 1.38]). In patients with intracranial aneurysms, aspirin use was greater in patients without subarachnoid hemorrhage (OR 0.37 [0.24, 0.58]), although these studies were at higher risk of bias.

Conclusions

There is an association between aspirin use and subarachnoid hemorrhage in patients with intracranial aneurysms. This apparent protective relationship is not seen in the general population. Prospective randomized studies are required to further investigate the effect of aspirin on unruptured intracranial aneurysms.
Teleneurology Comprehensive Inpatient Consultations Expedite Access to Care and Decreases Hospital Length of Stay
Authors: McCormick Robert , Estrada Juan , Whitney Cynthia , Hinrichsen Mona , Lee Patrick T. , Cohen Adam B. , Schwamm Lee , Matiello Marcelo
Published: March 2021

Background and Purpose:

While the successful provision of telestroke care has been well documented in the literature, studies on the impact of comprehensive teleneurology service (TN) to hospital measures are lacking. We evaluated 3 traditional health services metrics of hospital performance: time from consult request to consult completion, inpatient length of stay (LOS), and the rate of patients transferred for tertiary care.

Methods:

Medical records (n = 899) from 3 community hospitals and our TN consultation database were retrospectively reviewed during the 2 years before (n = 703, 3 hospitals) and 4 months (n = 2 hospitals) to 2 years (n = 1 hospital) after implementation (n = 196) of a TN program for routine and urgent consult requests. Consult order time, consult completion time, total length of stay and discharge disposition were compared across the pre-TN implementation group, which consisted of in-person consultations and the post-TN implementation group, which consisted of TN consultations only.

Results:

After TN implementation, median length of stay decreased 28% (3.9 vs. 2.8 days, p < 0.0001) and median time from consult order to consult completion decreased by 74% across all diagnoses (5.8 vs. 1.5 hours, p < 0.0001). There were no significant differences in the percentage of patients discharged home (52.3% vs. 56.1%, p = 0.10) or transferred to tertiary care (6.1% to 9.2%, p = 0.10).

Conclusions:

Implementation of TN program was associated with significant reductions in LOS and time to consultation completion without an increase in shunting of patients to more advanced facilities. Further research is warranted to confirm these findings in independent cohorts and other models of teleneurology delivery.
Preoperative “Cervical Axis” Deviation Increases the Risk of Distal Adding-On Following Surgery in Lenke 1 and 2 Adolescent Idiopathic Scoliosis Patients
Authors: Chan Chris Yin Wei , Ch’ng Pei Ying , Lee Sin Ying , Chung Weng Hong , Chiu Chee Kidd , Kwan Mun Keong
Published: March 2021

Study Design:

Retrospective.

Purpose:

To evaluate the relationship between shoulder/ neck imbalance with distal adding-on phenomenon and to identify other risk factors in Lenke 1 and 2 (non-AR curves) adolescent idiopathic scoliosis (AIS) patients.

Methods:

100 Lenke 1 and 2 AIS patients with lowest instrumented vertebra (LIV) cephalad to or at L1 were recruited. Medial shoulder/ neck balance was represented by T1-tilt and cervical axis (CA). Lateral shoulder balance was represented by clavicle angle (Cla-A) and radiographic shoulder height (RSH). Distal adding-on phenomenon was diagnosed when there was disc wedging below LIV of >5o at final follow-up. Predictive factors and odds ratio were derived using univariate and multivariate logistic regression analysis.

Results:

Mean age of this cohort was 15.9 ± 4.4 years. Mean follow-up duration was 30.9 ± 9.6 months. Distal adding-on phenomenon occurred in 19 patients (19.0%). Only Risser grade, preoperative CA and final follow-up lumbar Cobb angle were the independent factors. A positive preoperative CA deviation increased the odds of distal adding-on by 5.4 times (95% CI 1.34-21.51, P = 0.018). The mean immediate postoperative T1-tilt, CA, RSH and Cla-A were comparable between the group with distal adding-on and the group without.

Conclusion:

Distal adding-on phenomenon occurred in 19.0% of patients. Preoperative “Cervical Axis” was an important factor and it increased the risk of distal adding-on by 5.4 times. Other significant predictive factors were Risser grade and lumbar Cobb angle at final follow-up. Immediate postoperative shoulder or neck imbalance was not a significant factor for postoperative distal adding-on phenomenon.
Acellular Cartilage Repair Technique Based on Ultrapurified Alginate Gel Implantation for Advanced Capitellar Osteochondritis Dissecans
Authors: Momma Daisuke , Onodera Tomohiro , Kawamura Daisuke , Urita Atsushi , Matsui Yuichiro , Baba Rikiya , Funakoshi Tadanao , Kondo Makoto , Endo Toshiya , Kondo Eiji , Iwasaki Norimasa
Published: March 2021

Background:

One of the most important limitations of osteochondral autograft transplant is the adverse effect on donor sites in the knee. Ultrapurified alginate (UPAL) gel is a novel biomaterial that enhances hyaline-like cartilage repair for articular defects. To avoid the need for knee cartilage autografting when treating osteochondritis dissecans (OCD) of the capitellum, we developed a surgical procedure involving a bone marrow stimulation technique (BMST) augmented by implantation of UPAL gel.

Hypothesis:

BMST augmented by UPAL gel implantation improves the cartilage repair capacity and provides satisfactory clinical outcomes in OCD of the capitellum.

Study Design:

Case series; Level of evidence, 4.

Methods:

A total of 5 athletes with advanced capitellar OCD in the dominant elbow underwent BMST augmented by implantation of UPAL gel. The osteochondral defects were filled with UPAL gel after BMST. At a mean follow-up of 97 weeks, all patients were evaluated clinically and radiographically.

Results:

At final follow-up, all 5 patients had returned to competitive-level sports, and 4 patients were free from elbow pain. The mean Timmerman-Andrews score significantly improved from 100 to 194 points. Radiographically, all patients exhibited graft incorporation and a normal contour of the subchondral cortex. Magnetic resonance imaging showed that the preoperative heterogeneity of the lesion had disappeared, and the signal intensity had returned to normal. Arthroscopic examinations consistently exhibited improvement in the International Cartilage Regeneration and Joint Preservation Society (ICRS) grade of lesions from 3 or 4 to 1 or 2 in 4 patients at 85 weeks postoperatively. Histologic analysis of biopsy specimens revealed an average total ICRS Visual Assessment Scale II histologic score of 1060.

Conclusion:

The acellular cartilage repair technique using UPAL gel for advanced capitellar OCD provided satisfactory clinical and radiographic results. The present results suggest that this novel technique is a useful, minimally invasive approach for treating cartilaginous lesions in athletes.
Delegation and Decentralization: Reform Ideas for Bihar’s Economic Transformation
Authors: Khemani Stuti
Published: March 2021

This article proposes reform ideas for Bihar using advances in economics research on the role of institutions in economic development. Institutions—the formal and informal rules of the ‘game’ of how people interact in society—are fundamental determinants of economic activity and entrepreneurship. Historical institutions of caste-based feudalism in Bihar have been regarded as depressing entrepreneurship and encouraging lawlessness and corruption. New survey data–based evidence shows the potential of two reforms to bring about Bihar’s institutional and economic transformation: greater delegation of public policy implementation in bureaucracies and greater decentralization of public policy selection to local governments. Greater delegation means giving autonomy and discretion to agents in bureaucracies, and promoting professional norms for service delivery rather than hierarchical monitoring and disciplining to achieve performance. Greater decentralization means that more policy choices—such as on the composition of public expenditures, tariffs and fees for public infrastructure—are made by local leaders who gain the power to make these choices by winning more local elections. Communication within bureaucracies and through local media about the performance of public policies is part of these institutional reforms. Taken together, these can reduce the influence of patronage politics and enable the selection of leaders who pursue policies in the broad public interest. In turn, these institutional changes can spur greater economic activity and entrepreneurship, including all social groups in growth and prosperity.
Management of hospitalised adults with coronavirus disease 2019 (COVID-19): a European Respiratory Society living guideline
Authors: Chalmers James D. , Crichton Megan L. , Goeminne Pieter C. , Cao Bin , Humbert Marc , Shteinberg Michal , Antoniou Katerina M. , Ulrik Charlotte Suppli , Parks Helen , Wang Chen , Vandendriessche Thomas , Qu Jieming , Stolz Daiana , Brightling Christopher , Welte Tobias , Aliberti Stefano , Simonds Anita K. , Tonia Thomy , Roche Nicolas
Published: March 2021

Introduction

Hospitalised patients with coronavirus disease 2019 (COVID-19) as a result of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have a high mortality rate and frequently require non-invasive respiratory support or invasive mechanical ventilation. Optimising and standardising management through evidence-based guidelines may improve quality of care and therefore patient outcomes.

Methods

A task force from the European Respiratory Society, and endorsed by the Chinese Thoracic Society, identified priority interventions (pharmacological and non-pharmacological) for inclusion in this “living guideline” using the PICO (Population, Intervention, Comparator, Outcomes) format. The GRADE (Grading of Recommendations, Assessment, Development and Evaluations) approach was used for assessing the quality of evidence and strength of recommendations. Systematic literature reviews were performed, and data pooled by meta-analysis where possible. Evidence tables were presented and evidence-to-decision frameworks were used to formulate recommendations.

Results

Based on the available evidence at the time of guideline update (14 February 2022) the panel makes a strong recommendation in favour of the use of systemic corticosteroids in patients requiring supplementary oxygen or ventilatory support, and of interleukin-6 receptor antagonist monoclonal antibodies or baricitinib for patients requiring supplementary oxygen and for the use of anticoagulation in hospitalised patients. The panel makes a conditional recommendation for continuous positive airway pressure in patients with acute hypoxaemic respiratory failure and for combination treatment with casirivimab and imdevimab in patients who have no detectable SARS-CoV-2 spike antibodies (seronegative) and a susceptible variant. No recommendation was made for remdesivir in patients requiring supplemental oxygen. The panel recommended against multiple therapeutics, including hydroxychloroquine, azithromycin, convalescent plasma, lopinavir-ritonavir and colchicine. Further recommendations for research are made.

Conclusion

Several interventions reduce mortality and improve clinical outcomes in patients with severe COVID-19 infection. These guidelines will be regularly updated as further evidence becomes available.
Official ERS technical standard: Global Lung Function Initiative reference values for static lung volumes in individuals of European ancestry
Authors: Hall Graham L. , Filipow Nicole , Ruppel Gregg , Okitika Tolu , Thompson Bruce , Kirkby Jane , Steenbruggen Irene , Cooper Brendan G. , Stanojevic Sanja
Published: March 2021

Background

Measurement of lung volumes across the life course is critical to the diagnosis and management of lung disease. The aim of the study was to use the Global Lung Function Initiative methodology to develop all-age multi-ethnic reference equations for lung volume indices determined using body plethysmography and gas dilution techniques.

Methods

Static lung volume data from body plethysmography and gas dilution techniques from individual, healthy participants were collated. Reference equations were derived using the LMS (lambda-mu-sigma) method and the generalised additive models of location shape and scale programme in R. The impact of measurement technique, equipment type and being overweight or obese on the derived lung volume reference ranges was assessed.

Results

Data from 17 centres were submitted and reference equations were derived from 7190 observations from participants of European ancestry between the ages of 5 and 80 years. Data from non-European ancestry populations were insufficient to develop multi-ethnic equations. Measurements of functional residual capacity (FRC) collected using plethysmography and dilution techniques showed physiologically insignificant differences and were combined. Sex-specific reference equations including height and age were developed for total lung capacity (TLC), FRC, residual volume (RV), inspiratory capacity, vital capacity, expiratory reserve volume and RV/TLC. The derived equations were similar to previously published equations for FRC and TLC, with closer agreement during childhood and adolescence than in adulthood.

Conclusions

Global Lung Function Initiative reference equations for lung volumes provide a generalisable standard for reporting and interpretation of lung volumes measurements in individuals of European ancestry.
The isobaric pulmonary arterial compliance in pulmonary hypertension
Authors: Chemla Denis , Berthelot Emmanuelle , Weatherald Jason , Lau Edmund M. T. , Savale Laurent , Beurnier Antoine , Montani David , Sitbon Olivier , Attal Pierre , Boulate David , Assayag Patrick , Humbert Marc , Hervé Philippe
Published: March 2021

Pulmonary hypertension is associated with stiffening of pulmonary arteries which increases right ventricular pulsatile loading. High pulmonary artery wedge pressure (PAWP) in postcapillary pulmonary hypertension (Pc-PH) further decreases pulmonary arterial compliance (PAC) at a given pulmonary vascular resistance (PVR) compared with precapillary pulmonary hypertension, thus responsible for a higher total arterial load. In all other vascular beds, arterial compliance is considered as mainly determined by the distending pressure, due to non-linear stress-strain behaviour of arteries. We tested the applicability, advantages and drawbacks of two comparison methods of PAC depending on the level of mean pulmonary arterial pressure (mPAP; isobaric PAC) or PVR.

Right heart catheterisation data including PAC (stroke volume/pulse pressure) were obtained in 112 Pc-PH (of whom 61 had combined postcapillary and precapillary pulmonary hypertension) and 719 idiopathic pulmonary arterial hypertension (iPAH).

PAC could be compared over the same mPAP range (25–66 mmHg) in 792 (95.3%) out of 831 patients and over the same PVR range (3–10.7 WU) in only 520 (62.6%) out of 831 patients. The main assumption underlying comparisons at a given PVR was not verified as the PVR×PAC product (RC-time) was not constant but on the contrary more variable than mPAP. In the 788/831 (94.8%) patients studied over the same PAC range (0.62–6.5 mL·mmHg−1), PVR and thus total arterial load tended to be higher in iPAH.

Our study favours comparing PAC at fixed mPAP level (isobaric PAC) rather than at fixed PVR. A reappraisal of the effects of PAWP on the pulsatile and total arterial load put on the right heart is needed, and this point deserves further studies.
Metagenomic sequencing revealed the potential of banknotes as a repository of microbial genes
Authors: Lin Jun , Jiang Wenqian , Chen Lin , Zhang Huilian , Shi Yang , Liu Xin , Cai Weiwen
Published: March 2021

Background

Genetic resources are important natural assets. Discovery of new enzyme gene sequences has been an ongoing effort in biotechnology industry. In the genomic age, genomes of microorganisms from various environments have been deciphered. Increasingly, it has become more and more difficult to find novel enzyme genes. In this work, we attempted to use the easily accessible banknotes to search for novel microbial gene sequences.

Results

We used high-throughput genomic sequencing technology to comprehensively characterize the diversity of microorganisms on the US dollars and Chinese Renminbis (RMBs). In addition to finding a vast diversity of microbes, we found a significant number of novel gene sequences, including an unreported superoxide dismutase (SOD) gene, whose catalytic activity was further verified by experiments.

Conclusions

We demonstrated that banknotes could be a good and convenient genetic resource for finding economically valuable biologicals.
IGFBP-1 and IGFBP-2 are associated with a decreased pulse-wave velocity in young, healthy adults
Authors: Pettersson-Pablo Paul , Nilsson Torbjörn K. , Breimer Lars H. , Hurtig-Wennlöf Anita
Published: March 2021

Background and aims

In healthy, young adults we analyzed a panel of cardiovascular disease related proteins in plasma and compared them with the vascular health of the subjects. The aim was to identify proteins with a relationship to the early atherosclerotic process in healthy individuals.

Methods

We employed the proximity extension assay from OLINK proteomics to analyze 92 cardiovascular disease (CVD) related proteins on 833 subjects (men and women, ages 18–26). The women were further divided into an estrogen-using group and non-users. Protein expression was analyzed using principal component analysis (PCA). The following vascular examinations were performed: Pulse-wave velocity (PWV), augmentation index (AIX), carotid-intima media thickness (cIMT).

Results

Three principal components were obtained using PCA to analyze the protein expression. None of the obtained principal components correlated significantly with AIX or cIMT. One of the components, explaining 6% of the total variance of the data, was significantly correlated with PWV. Upon examination of the proteins with the highest factor loadings on this component independently in a multivariable model, adjusting for established CVD risk biomarkers, insulin-like growth factor-binding protein 1 (IGFBP-1) and insulin-like growth factor-binding protein 2 (IGFBP-2) were found to independently, negatively correlate with PWV. Among the established risk factors included in the multivariable model, age was significantly and adversely correlated with all vascular measurements.

Conclusions

In this population of healthy, young adults, groups of CVD related proteins correlate with PWV, but not AIX or cIMT. This group of proteins, of which IGFBP-1 and IGFBP-2 were independently, negatively correlated in a multivariable model with PWV, could have benificial effects on vascular stiffness. The robust association between age and PWV, AIX and cIMT provide insight into the impact of aging on the vasculature, which is detectable even in a population of young, healthy, non-smoking individuals of ages spanning only 8 years.
Early detection of cervical cancer in western Kenya: determinants of healthcare providers performing a gynaecological examination for abnormal vaginal discharge or bleeding
Authors: Mwaliko Emily , Van Hal Guido , Bastiaens Hilde , Van Dongen Stefan , Gichangi Peter , Otsyula Barasa , Naanyu Violet , Temmerman Marleen
Published: March 2021

Background

In western Kenya, women often present with late-stage cervical cancer despite prior contact with the health care system. The aim of this study was to predict primary health care providers’ behaviour in examining women who present with abnormal discharge or bleeding.

Methods

This was a cross-sectional survey using the theory of planned behaviour (TPB). A sample of primary health care practitioners in western Kenya completed a 59-item questionnaire. Structural equation modelling was used to identify the determinants of providers’ intention to perform a gynaecological examination. Bivariate analysis was conducted to investigate the relationship between the external variables and intention.

Results

Direct measures of subjective norms (DMSN), direct measures of perceived behavioural control (DMPBC), and indirect measures of attitude predicted the intention to examine patients. Negative attitudes toward examining women had a suppressor effect on the prediction of health workers’ intentions. However, the predictors of intention with the highest coefficients were the external variables being a nurse (β = 0.32) as opposed to a clinical officer and workload of attending less than 50 patients per day (β = 0.56).

In bivariate analysis with intention to perform a gynaecological examination, there was no evidence that working experience, being female, having a lower workload, or being a private practitioner were associated with a higher intention to conduct vaginal examinations. Clinical officers and nurses were equally likely to examine women.

Conclusions

The TPB is a suitable theoretical basis to predict the intention to perform a gynaecological examination. Overall, the model predicted 47% of the variation in health care providers’ intention to examine women who present with recurrent vaginal bleeding or discharge. Direct subjective norms (health provider’s conformity with what their colleagues do or expect them to do), PBC (providers need to feel competent and confident in performing examinations in women), and negative attitudes toward conducting vaginal examination accounted for the most variance. External variables in this study also contributed to the overall variance. As the model in this study could not explain 53% of the variance, investigating other external variables that influence the intention to examine women should be undertaken.