bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Approach for Bounding the Stress Experienced by the Core of Utility-Scale Printed Circuit Heat Exchangers Under Thermohydraulic Loads
Authors: Katz Alon , Messner Mark C. , Ranjan Devesh
Published: August 2021

Printed circuit heat exchangers (PCHEs) have rapidly gained popularity since being introduced nearly three decades ago, and they are currently widely deployed in the petrochemical and aviation industry. Their compactness, thermohydraulic efficiency, inherent suitability for high temperature/pressure fluids containment, and demonstrated durability are some of the reasons the nuclear industry is seeking to adopt this technology as well. However, the relatively strict nuclear-related regulatory design code, especially when classified as critical to the safety of the reactors, is posing challenges to adopting the technology. From stress analysis point of view, one undesirable feature of PCHEs is their geometrical complexity, which is implied by their multilength-scale features. As a result, a full-scale model of a utility-scale exchanger cannot simply be solved on a computer because meshing such components results in a vast number of degrees-of-freedom. This work seeks to address the challenge of stress analyses to PCHEs by presenting a method to simplify the geometry of PCHE designs. The models proposed by this work can be practically analyzed on a standard computer and provide a path for implementing ASME design rules. The analyses presented herein are divided into five separate investigations. Each is carried out to incrementally simplify the analyzed model by addressing features such as the shapes of the flow passages, the complex distribution of stress in large components, the three-dimensionality of the stress and strain, the thermal stresses caused by thermohydraulic operation observed experimentally and more.
Neuromodulation Applications for Chronic Pain
Authors: Persaud-Sharma Dharam , William Mallet John , Panjeton Geoffrey Danial , Ogbemudia Blessing , Ahmad Affan , Coombes Stephen , Antony Ajay
Published: August 2021

Chronic back pain is highly prevalent worldwide, affecting over 10% of the global population. It is a complex medical problem that affects individuals, families, and communities and has a costly economic impact through an impaired workforce. Pain mechanisms are complicated and include biological, psychological, and social components that can combine to drive unique pain experiences. Beyond conservative management with multimodal pharmacotherapy and more invasive surgical intervention for an identifiable anatomical abnormality, there are limited therapies for the resolution of chronic pain. However, exciting technological developments in spinal cord stimulation have renewed interest in neuromodulation for patients with refractory pain after both conservative and surgical management. Here, we review the efficacy of spinal cord stimulator technologies and other related technologies, including dorsal root ganglion stimulators and peripheral nerve stimulators, as well as highlight future areas of research.
Robotic Tensegrity Structure With a Mechanism Mimicking Human Shoulder Motion
Authors: Li Lengxue , Kim Sunhong , Park Junho , Choi Youngjin , Lu Qiang , Peng Dongliang
Published: August 2021

This paper proposes a three degrees-of-freedom tensegrity structure with a mechanism inspired by the ligamentous structure of the shoulder. The proposed mechanism simulates the wide motion ranges of the human shoulder joint and is composed of 3 rigid bodies and 16 steel wires with 3 mutually perpendicular rotating axes. Since it belongs to the class 1 tensegrity structure that the rigid bodies do not make any contact with each other, the joint has a certain amount of flexibility, which not only can help protect its mechanism from external impacts but also can prevent human injury that might happen when the mechanism and humans interact each other. Moreover, the proposed mechanism can be manufactured using fewer materials than a fully rigid mechanism, and thus, it can be made in a lightweight fashion and reduce the inertial effects as well. Finally, to actuate the robotic shoulder, the cables connected to each motor are able to drive the rotating shafts of the joint mechanism.
Analytical Modeling of Machining Forces and Friction Characteristics in Ultrasonic-Assisted Turning Process
Authors: Airao Jay , Nirala Chandrakant K.
Published: August 2021

Intermittent cutting characteristics of ultrasonic-assisted turning (UAT), compared with conventional turning (CT), has shown a significant enhancement in the machinability of hard-to-cut materials. The enhancement in machinability is associated with machining forces and friction characteristics of the process. The present article covers an analytical approach to predict the output responses such as machining forces and friction characteristics in UAT and CT processes. Specific cutting energy (SCE) for a particular work-piece material was considered to predict the output responses. The predictions were made by considering the conventional machining theories. Experiments for the UAT and the CT of SS 304 were carried out to validate the predicted model. The results from the analytical model showed that the shear angle increases and the tool work-piece contact ratio (TWCR) decrease with an increase in amplitude and frequency of vibration. The results obtained from the analytical model were found to be in close agreement with the experimental ones, with an approximate error of 2–20%.
Impact of Cooling Injection on Shock Wave Over a Flat Tip in High Pressure Turbine
Authors: Ma Haiteng , Zeng Wei , Jiang Hongmei , Hong Jun
Published: August 2021

Cooling design of highly loaded turbine blade tips is challenged by the scarcity of experimental data and the lack of physical understanding in cooling and overtip leakage (OTL) interaction under transonic conditions. To address these issues, this paper carried out transient thermal measurements through infrared thermography on a transonic flat tip with and without cooling injection. Experimental data of Nusselt number and cooling effectiveness were obtained and compared with computational fluid dynamics (CFD) results for numerical validation. Both experimental data and simulation results show that cooling injection drastically augments tip Nusselt number near pressure side (PS) which is upstream of ejection, and in areas around coolant holes. Moreover, a strikingly low Nusselt number stripe is observed downstream of cooling injection from one of the holes in aft portion of blade. The strip is directed transverse to local OTL streamline flowing from pressure to suction side (SS) and sprawls to adjacent coolant wakes. Further numerical analyses concluded that cooling injection changes tip aerodynamics and overtip shock wave structure fundamentally. Oblique shock waves across the uncooled flat tip are replaced by a confined shock train downstream of cooling injection and between cooling holes, which is constituted by two shocks normal to local OTL flow coming from pressure side. Across the first shock, density and pressure increases abruptly, contributing to thickening of tip boundary layer and the plummet of skin friction on tip surface, which is responsible for the sharp decline of tip Nusselt number and therefore, formation of low heat transfer stripe downstream cooling injection.
Global Optimization of a Transonic Fan Blade Through AI-Enabled Active Subspaces
Authors: Lopez Diego I. , Ghisu Tiziano , Shahpar Shahrokh
Published: August 2021

The increased need to design higher performing aerodynamic shapes has led to design optimization cycles requiring high-fidelity CFD models and high-dimensional parametrization schemes. The computational cost of employing global search algorithms on such scenarios has typically been prohibitive for most academic and industrial environments. In this paper, a novel strategy is presented that leverages the capabilities of artificial neural networks for regressing complex unstructured data, while coupling them with dimensionality reduction algorithms. This approach enables employing global-based optimization methods on high-dimensional applications through a reduced computational cost. This methodology is demonstrated on the efficiency optimization of a modern jet engine fan blade with constrained pressure ratio. The outcome is compared against a state-of-the-art adjoint-based approach. Results indicate that the strategy proposed achieves comparable improvements to its adjoint counterpart with a reduced computational cost and can scale better to multi-objective optimization applications.
Investigating Gas Turbine Internal Cooling Using Supercritical CO2 at Higher Reynolds Numbers for Direct Fired Cycle Applications
Authors: Searle Matthew , Roy Arnab , Black James , Straub Douglas , Ramesh Sridharan
Published: August 2021

Experimental and numerical investigations of three variants of internal cooling configurations—dimples only, ribs only, and ribs with dimples have been explored at process conditions (96 °C and 207 bar) with sCO2 as the coolant. The designs were chosen based on advanced internal cooling features typically used for air-breathing gas turbines. The experimental study described utilizes additively manufactured square channels with the cooling features over a range of Reynolds number from 80,000 to 250,000. Nusselt number is experimentally calculated utilizing the Wilson Plot method and three heat transfer characteristics—augmentation in Nusselt number, friction factor, and overall thermal performance factor (TPF) are reported. To explore the effect of surface roughness introduced due to additive manufacturing, two baseline flow cases are considered—a conventional smooth tube and an additively manufactured square tube. A companion computational fluid dynamics (CFD) simulation is also performed for the corresponding cooling configurations reported in the experiments using the Reynolds-averaged Navier–Stokes (RANS) based turbulence model. Both experimental and computational results show increasing Nusselt number augmentation as higher Reynolds numbers are approached, whereas prior work on internal cooling of air-breathing gas turbines predict a decay in the heat transfer enhancement as Reynolds number increases. Comparing cooling features, it is observed that the “ribs only” and “ribs with dimples” configurations exhibit higher Nusselt number augmentation at all Reynolds numbers compared with the “dimples only” and the “no features” configurations. However, the frictional losses are almost an order of magnitude higher in the presence of ribs.
Evaluation method for acoustic underwater propulsion systems
Authors: Kong Deqing , Qian Yuan , Kurosawa Minoru Kuribayashi , Aoyagi Manabu
Published: August 2021

Acoustic underwater propulsion systems based on bulk acoustic waves and surface acoustic waves have been studied. In this study, an acoustic propulsion system that consists of a 2.065-MHz thickness-vibration-mode lead-zirconate-titanate ultrasonic transducer is evaluated. A prototype swimmer is designed and fabricated. The admittance difference of the transducer in water and air is investigated. The vibration amplitude of the transducer is measured to evaluate transducer performance. The acoustic radiation force is calculated to describe acoustic propulsion. The zero-speed propulsion (ZSP) force and no-load speed (NLS) are measured in water. Swimmer movement starts at a NLS of 6.1 mm/s and a ZSP force of 0.2 mN for an input voltage and input power of 12.4 V peak to peak and 0.4 W, respectively. Although the average efficiency of the acoustic propulsion system is 69% in water, the overall movement efficiency of the swimmer is less than 1% because of fluid resistance and wire traction. Based on admittance, acoustic propulsion calculations, ZSP force, NLS measurements, and efficiency analysis, an evaluation method is proposed for optimizing swimmers with an acoustic underwater propulsion system. Small size, high power density, and simple structure of an acoustic propulsion system with an ultrasonic transducer make such systems suitable for applications such as pipeline inspection and repair.
Circuit model for thermoviscous propagation in annular waveguides
Authors: Ricci Yuri , La Torraca Paolo , Larcher Luca
Published: August 2021

This paper presents a circuit model of the thermoviscous acoustic wave propagation in waveguides with annular cross section. The model, validated against finite element method simulations of the input acoustic impedance, captures the annular waveguide behavior with good accuracy within a frequency bandwidth consistent with the lumped-element approximation. The cascading of multiple circuit models easily allows extending the bandwidth while preserving the same accuracy. The circuit model was derived from the low reduced frequency (LRF) wave propagation model in rectangular layers, representing a valid approximation of the complex LRF solution in annular waveguides. The simplified analytical description allows for the formulation of a compact T-network model comprised of standard circuit elements. This circuit model can be implemented in circuit simulators to accelerate both the analysis and engineering of devices having elements with annular cross section, such as micro-electro-mechanical systems devices or microphones.
Model-based localization of deep-diving cetaceans using towed line array acoustic data
Authors: Barkley Yvonne M. , Nosal Eva-Marie , Oleson Erin M.
Published: August 2021

Passive acoustic monitoring using a towed line array of hydrophones is a standard method for localizing cetaceans during line-transect cetacean abundance surveys. Perpendicular distances estimated between localized whales and the trackline are essential for abundance estimation using acoustic data. Uncertainties in the acoustic data from hydrophone movement, sound propagation effects, errors in the time of arrival differences, and whale depth are not accounted for by most two-dimensional localization methods. Consequently, location and distance estimates for deep-diving cetaceans may be biased, creating uncertainty in abundance estimates. Here, a model-based localization approach is applied to towed line array acoustic data that incorporates sound propagation effects, accounts for sources of error, and localizes in three dimensions. The whale's true distance, ship trajectory, and whale movement greatly affected localization results in simulations. The localization method was applied to real acoustic data from two separate sperm whales, resulting in three-dimensional distance and depth estimates with position bounds for each whale. By incorporating sources of error, this three-dimensional model-based approach provides a method to address and integrate the inherent uncertainties in towed array acoustic data for more robust localization.
A three-dimensional finite difference model for ocean acoustic propagation and benchmarking for topographic effects
Authors: Liu Wei , Zhang Lilun , Wang Wenke , Wang Yongxian , Ma Shuqing , Cheng Xinghua , Xiao Wenbin
Published: August 2021

A three-dimensional (3D) finite difference (FD) model with formal fourth-order accuracy has been developed for the ocean acoustic Helmholtz equation (HE), which can be used to address arbitrary bathymetry and provide more accurate benchmark solutions for other 3D underwater acoustic approximate models. The derivatives in the acoustic HE are numerically discretized based on regular grids, and the perfectly matched layer is introduced to absorb unphysical reflections from the boundaries where Sommerfeld radiation conditions are deployed. The system of linear equations is solved using a parallel matrix-free geometric multigrid preconditioned biconjugate gradient stabilized iteration method, and the code (named COACH) is run on the Tianhe-2 supercomputer in China. Four 3D topographic benchmark acoustic cases—a wedge waveguide, Gaussian canyon, conical seamount, and corrugated seabed—are simulated to test the present FD model, and the maximum number of grid points reaches 33.15 × 109 in the wedge waveguide case, running in parallel with 988 central processing unit cores. Furthermore, the accuracy and generality of the present model have been verified by solution comparisons with other available 3D acoustic propagation models, and the two-dimensional and 3D transmission loss contours are presented to facilitate the distinguishing among the acoustic field features of these cases.
A Reflection on the State of Sport Coaching Research, Its Community, and Representation: The 2020 International Council for Coaching Excellence Research Committee Consultation
Authors: North Julian , Callary Bettina , Dieffenbach Kristen , Galatti Larissa , Lara-Bercial Sergio , Nash Christine , O’Connor Donna
Published: August 2021

This article provides an overview of the context, details, and outcomes of a consultation and review of the International Council for Coaching Excellence’s interactions and engagements with, and service provision to, the international sport coaching research community. The consultation and review were undertaken by the International Council for Coaching Excellence Research Committee (RC). The paper starts with a description of the sport coaching research landscape. It then provides details of the role of the International Council for Coaching Excellence, its Research Fair, and RC. The paper then offers an overview of the formal initiation of the consultation and review at the Global Coach Conference, Japan 2019, as well as a brief overview of the approach used. It then details the consultation findings providing direction for the RC moving forward. The resultant revised RC terms of reference are included as an appendix.
Factors That Influence Walking Intervention Adherence for Older Adults Living in Retirement Communities
Authors: Davila Victoria S. , Conroy David E. , Danilovich Margaret K.
Published: August 2021

Walking interventions improve health outcomes among older adults. However, few clinical trials evaluate long-term behavior change adherence. The authors explored factors that influence walking adherence in older adults following their participation in a clinical trial. They conducted n = 7 focus groups with n = 23 participants enrolled in the parent study (ClinicalTrials.gov number: NCT03654807). The authors used content analysis to code data according to the social–ecological model. They found that supportive services (exercise classes) in retirement communities have multilevel impacts on adherence to walking activity. Residents from communities offering services continued walking because of increased confidence gained in the parent trial, while residents in communities without services were motivated by their functional improvements. Residents voiced frustration with retirement community physical activity programs that did not address the full spectrum of physical functioning. Findings support the need for retirement communities to account for various motivational factors in tailoring programs to promote increased physical activity for older adults.
Lifetime mobility of an Arctic woolly mammoth
Authors: Wooller Matthew J. , Bataille Clement , Druckenmiller Patrick , Erickson Gregory M. , Groves Pamela , Haubenstock Norma , Howe Timothy , Irrgeher Johanna , Mann Daniel , Moon Katherine , Potter Ben A. , Prohaska Thomas , Rasic Jeffrey , Reuther Joshua , Shapiro Beth , Spaleta Karen J. , Willis Amy D.
Published: August 2021

A mammoth’s life

Fossils have long given us glimpses of the life that came before us, but these glimpses are generally static. They tell us a bit about species that lived, but not much about how they lived. Evolving techniques are deepening our viewpoint. Wooller
et al
. examined isotopes collected from the tusk of a 17,000-year-old mammoth to elucidate his movements from birth to death. This included his time—likely with a herd—as an infant and juvenile, then as a prime age adult, and then a declining senior over his approximately 28-year life span. —SNV
Integrate biodiversity targets from local to global levels
Authors: Obura David O. , Katerere Yemi , Mayet Mariam , Kaelo Dickson , Msweli Simangele , Mather Khalid , Harris Jean , Louis Maxi , Kramer Rachel , Teferi Taye , Samoilys Melita , Lewis Linzi , Bennie Andrew , Kumah Frederick , Isaacs Moenieba , Nantongo Pauline
Published: August 2021

A shared Earth approach links biodiversity and people
Searching for life on Mars and its moons
Authors: Hyodo Ryuki , Usui Tomohiro
Published: August 2021

Sample-return missions will look for extraterrestrial life and biomarkers on Mars and Phobos
Hybrid radical-polar pathway for excision of ethylene from 2-oxoglutarate by an iron oxygenase
Authors: Copeland Rachelle A. , Zhou Shengbin , Schaperdoth Irene , Shoda Tokufu Kent C. , Bollinger J. Martin , Krebs Carsten
Published: August 2021

Tracing a path to ethylene

Ethylene is produced industrially from fossil carbon sources, but plants and microbes produce small amounts through a handful of unusual enzymatic reactions. Copeland
et al
. studied a microbial ethylene-forming enzyme using oxygen isotope–tracing experiments and biochemical assays to test mechanistic proposals. This enzyme, which uses a non–heme iron center to activate oxygen, catalyzes two distinct oxidation reactions with different mechanisms. One reaction is entirely off-pathway and results in fragmentation of a co-substrate, arginine. The other reaction can completely fragment 2-oxoglutarate into ethylene, bicarbonate, and two molecules of carbon dioxide; however, it occasionally derails and yields an omega–hydroxy acid product. —MAF
When did terrestrial plants arise?
Authors: Gensel Patricia G.
Published: August 2021

Microfossils suggest that co-option of algal genes may affect land plant origination time
Richard C. Lewontin (1929–2021)
Authors: Berry Andrew , Petrov Dmitri A.
Published: August 2021

Groundbreaking evolutionary geneticist
Draft
De Novo
Genome Assembly of Acinetobacter pittii Strain VKPM B-3780, a Prospective Multifunctional Bioremediation Agent
Authors: Izotova A. O. , Petrova K. O. , Korzhenkov A. A. , Bavtushnyi A. A. , Sidoruk K. V. , Patrusheva E. V. , Patrushev M. V. , Kwon D. A. , Toshchakov S. V.
Published: August 2021

Acinetobacter pittii
strain B-3780 is a prospective degrader of oil and methanol, isolated from industrial wastewater. Here, we present the draft genome sequence of strain B-3780, obtained using Illumina sequencing of the fragment genomic library.
Complete Genome Sequence of Mycobacteriophage Joy99
Authors: Cox Faith , Katuri Josh , Adams Megan , Bachhofer Danielle , Cooper Ashleigh , Doty Jessica , Fuentes Miranda , Hanson Leeila , Miller Travis , Musgrave Jonathan , Palumbo Aleksey , Trautman Camille , Edwards Julie , Edwards Dustin
Published: August 2021

Joy99 is a siphoviral mycobacteriophage with a 59,837-base pair double-stranded DNA genome and is predicted to contain 97 protein-coding genes and a single tRNA gene. Joy99 was isolated in Saint Louis, MO, and annotated by students at Bluff Dale High School in community engagement with Tarleton State University.
Rhabdophane Th-Pb ages indicate reactivation of Mesoarchean structures in west Pilbara Craton during breakup of Greater India and Australia-Antarctica
Authors: Rasmussen Birger , Zi Jian-Wei , Muhling Janet R.
Published: August 2021

Uranium-Th-Pb dating of phosphate minerals in very low-grade metasedimentary rocks from the Archean Pilbara Craton, Western Australia, has revealed a long history of deformation and fluid flow during the Paleoproterozoic. However, this technique has not detected evidence for fluid flow along craton margins during Phanerozoic rifting and breakup. We report the use of in situ Th-Pb geochronology of rhabdophane, a hydrous light rare earth element phosphate, to date fluid flow in shale from the 2.76 Ga Mount Roe Basalt from drill hole number 6 of the Archean Biosphere Drilling Program (ABDP6), northwestern Pilbara Craton. Thorium-Pb dating of rhabdophane in carbonaceous shale yields three main populations with weighted mean 208Pb/232Th ages of 152 ± 6 Ma, 132 ± 4 Ma, and 119 ± 4 Ma, which indicates phosphate growth up to 2.64 b.y. after deposition. The rhabdophane ages are coeval with three major breakup events in eastern Gondwana: separation of Southwest Borneo and Argoland from Australia (ca. 156–152 Ma), breakup of Greater India from Australia (ca. 140–135 Ma), and separation of Greater India/India from Antarctica (ca. 123 Ma). The proximity of drill hole ABDP6 to major Mesoarchean faults and shear zones on the craton margin, which are parallel to rift propagation and basin development, points to episodic reactivation of ancient crustal structures >2.8 b.y. after their formation. Our results also highlight the potential of rhabdophane as a U-Th-Pb geochronometer for dating low-temperature (<200 °C) fluid flow and hydrous alteration. The migration of Mesozoic fluids through Archean shales adds weight to questions about the origin of geochemical signals in ancient altered rocks and how to extract information about the early environment and biosphere.
Late Weichselian ice-sheet flow directions in the Russian northern Barents Sea from high-resolution imagery of submarine glacial landforms
Authors: Dowdeswell Julian A. , Montelli Aleksandr , Akhmanov Grigorii , Solovyeva Marina , Terekhina Yana , Mironyuk Sergey , Tokarev Mikhail
Published: August 2021

The locations and orientations of more than 1000 late Quaternary subglacial and ice-marginal landforms, including streamlined sedimentary bed forms, glacitectonic hill-hole pairs, meltwater channels, and eskers, were mapped from blocks of multibeam data (area of 4861 km2) in the little-known Russian Barents Sea. Between Sentralbanken and Admiralty Bank, at ∼75°N, there is evidence for southward ice flow. Ice-flow indicators between Franz Josef Land and Novaya Zemlya show northeast flow into the head of St. Anna Trough. There is also evidence of southeast flow off the bank to the south of Franz Josef Land, and of flow convergence with northeast-flowing ice in Sedov Trough. Northeast flow of ice between Novaya Zemlya and Franz Josef Land suggests that the latter archipelago was not overrun by ice flowing north from the Barents Sea and, therefore, that a subsidiary ice dome was likely on Franz Josef Land. A major ice divide was also present at ∼76°N –77°N in the Russian Barents Sea.
Extrahepatic portal vein thrombosis in a pregnant patient with COVID-19: a rare thrombotic event survivor
Authors: Agarwal Mukta , Singh Smita , Sinha Upasna , Bhushan Divendu
Published: August 2021

A COVID-19 infection predisposes the infected person to thrombotic events. Myocardial infarction, acute limb ischaemia, mesenteric artery thrombosis and pulmonary embolism are all well-documented complications of this infection. Here we describe a pregnant patient who presented with obstructed labour with asymptomatic COVID-19 infection and developed ascites during the postoperative period. Further work-up of the patient revealed portal hypertension due to portal vein thrombosis (PVT). As the patient was healthy before this index pregnancy, a causative link between COVID-19 and PVT cannot be ruled out. Her COVID-19 infection progressed to a moderate disease. She was managed with steroids and appropriate antibiotics for secondary bacterial peritonitis. She was finally discharged after 2.5 months of multidisciplinary treatment. This is a case of a survivor of complications due to pregnancy, COVID-19 and extrahepatic portal vein obstruction.
Two-year longitudinal trajectory patterns of albuminuria and subsequent rates of end-stage kidney disease and all-cause death: a nationwide cohort study of biopsy-proven diabetic kidney disease
Authors: Yamanouchi Masayuki , Furuichi Kengo , Hoshino Junichi , Toyama Tadashi , Shimizu Miho , Yamamura Yuta , Oshima Megumi , Kitajima Shinji , Hara Akinori , Iwata Yasunori , Sakai Norihiko , Oba Yuki , Matsuoka Shusaku , Ikuma Daisuke , Mizuno Hiroki , Suwabe Tatsuya , Sawa Naoki , Yuzawa Yukio , Kitamura Hiroshi , Suzuki Yoshiki , Sato Hiroshi , Uesugi Noriko , Ueda Yoshihiko , Nishi Shinichi , Yokoyama Hitoshi , Nishino Tomoya , Samejima Kenichi , Kohagura Kentaro , Shibagaki Yugo , Makino Hirofumi , Matsuo Seiichi , Ubara Yoshifumi , Wada Takashi
Published: August 2021

Introduction

Data on the association between longitudinal trajectory patterns of albuminuria and subsequent end-stage kidney disease (ESKD) and all-cause mortality in diabetic kidney disease (DKD) are sparse.

Research design and methods

Drawing on nationally representative data of 329 patients with biopsy-proven DKD and an estimated glomerular filtration rate above 30 mL/min/1.73 m2at the time of biopsy, we used joint latent class mixed models to identify different 2-year trajectory patterns of urine albumin to creatinine ratio (UACR) and assessed subsequent rates of competing events: ESKD and all-cause death.

Results

A total of three trajectory groups of UACR were identified: ‘high-increasing’ group (n=254; 77.2%), ‘high-decreasing’ group (n=24; 7.3%), and ‘low-stable’ group (n=51; 15.5%). The ‘low-stable’ group had the most favorable risk profile, including the baseline UACR (median (IQR) UACR (mg/g creatinine): ‘low-stable’, 109 (50–138); ‘high-decreasing’, 906 (468–1740); ‘high-increasing’, 1380 (654–2502)), and had the least subsequent risk of ESKD and all-cause death among the groups. Although there were no differences in baseline characteristics between the ‘high-decreasing’ group and the ‘high-increasing’ group, the ‘high-decreasing’ group had better control over blood pressure, blood glucose, and total cholesterol levels during the first 2 years of follow-up, and the incidence rates of subsequent ESKD and all-cause death were lower in the ‘high-decreasing’ group compared with the ‘high-increasing’ group (incidence rate of ESKD (per 1000 person-years): 32.7 vs 77.4, p=0.014; incidence rate of all-cause death (per 1000 person-years): 0.0 vs 25.4, p=0.007).

Conclusions

Dynamic changes in albuminuria are associated with subsequent ESKD and all-cause mortality in DKD. Reduction in albuminuria by improving risk profile may decrease the risk of ESKD and all-cause death.
Reflections on benefits and challenges of longitudinal organisational network analysis as a tool for health systems research and practice
Authors: Glandon Douglas , Paina Ligia , Hoe Connie
Published: August 2021

As health systems practitioners and researchers increasingly turn towards systems thinking approaches and work on building interorganisational networks, they have demonstrated increasing interest in network analysis for investigating relationships and interactions between system actors, both at the individual and organisational levels. Despite the potential of network-based approaches to improve health system efficiency, effectiveness and responsiveness, both the theoretical and practical guidance on designing and evaluating network-building strategies is underdeveloped within the field. While there are multiple tools and resources to help users collect, manage and analyse network data, there is much less guidance on the practical applications of this information. One apparent gap is the limited application of longitudinal organisational network analysis, in which data are collected from the same organisational actors repeatedly over multiple time points. This yields insights into the dynamic nature of networks, including how the network structure and interactions change over time. Given that networks are rarely static, the addition of the time dimension has the potential to substantially enhance the analytical value of network analysis and contribute to more nuanced guidance for interested practitioners and policymakers. In this article, the authors draw on their experiences in conducting longitudinal network analysis of interorganisational relationships in the USA and India to comment on the opportunities and challenges of the methodology within the field of health systems research. We also provide suggestions as to how some of these challenges may be addressed or mitigated.
Are COVID-19 mitigation measures reducing preterm birth rate in China?
Authors: Bian Zheng , Qu Xiaoxian , Ying Hao , Liu Xiaohua
Published: August 2021

Objective

Preterm birth is the leading cause of child morbidity and mortality globally. We aimed to determine the impact of the COVID-19 mitigation measures implemented in China on 23 January 2020 on the incidence of preterm birth in our institution.

Design

Logistic regression analysis was used to investigate the association between the national COVID-19 mitigation measures implemented in China and the incidence of preterm birth.

Setting

Shanghai First Maternity and Infant Hospital, Shanghai China.

Participants

All singleton deliveries abstracted from electronic medical record between 1 January 2014 to 31 December 2020.

Main outcome measures

Preterm birth rate.

Results

Data on 164 107 singleton deliveries were available. COVID-19 mitigation measures were consistently associated with significant reductions in preterm birth in the 2-month, 3-month, 4-month, 5-month time windows after implementation (+2 months, OR 0.80, 95% CI 0.69 to 0.94; +3 months, OR 0.83, 95% CI 0.73 to 0.94; +4 months, OR 0.82, 95% CI 0.73 to 0.92; +5 months, OR 0.84, 95% CI 0.76 to 0.93). These reductions in preterm birth were obvious across various degrees of prematurity, but were statistically significant only in moderate-to-late preterm birth (32 complete weeks to 36 weeks and 6 days) subgroup. The preterm birth difference disappeared gradually after various restrictions were removed (7th–12th month of 2020, OR 1.02, 95% CI 0.94 to 1.11). There was no difference in stillbirth rate across the study time window.

Conclusion

Substantial decreases in preterm birth rates were observed following implementation of the national COVID-19 mitigation measures in China. Further study is warranted to explore the underlying mechanisms associated with this observation.
Pregnancy in Patients with Multiple Sclerosis
Authors: Arneth Borros M
Published: August 2021

Multiple sclerosis (MS) is an autoimmune disorder that affects ~2.5 million people globally. Women of reproductive age are highly susceptible to this disease. This study aims to explore the association between MS and pregnancy. Articles related to the topic under investigation were identified; the search terms included “pregnancy”, “multiple sclerosis”, “MS”, and “women”. Only articles published between 2010 and 2020 were included in the review. This review shows that researchers have attempted to explore the link between pregnancy and MS, and the results from previous studies indicate that pregnancy reduces the risk of MS relapse. However, evidence suggesting that pregnancy can affect the long-term progression of MS is lacking. The research results also indicate that MS does not increase the risk of maternal and fetal complications. MS remains a serious autoimmune disorder that affects many women worldwide. The data gathered during this review indicate that a significant correlation exists between pregnancy and MS relapse rates. The findings presented in this review can aid in the management of MS during pregnancy. Furthermore, these research results provide vital insights that caregivers can use to monitor patients with MS during pregnancy.
Multicenter phase II trial (SWOG S1609, cohort 51) of ipilimumab and nivolumab in metastatic or unresectable angiosarcoma: a substudy of dual anti-CTLA-4 and anti-PD-1 blockade in rare tumors (DART)
Authors: Wagner Michael J , Othus Megan , Patel Sandip P , Ryan Chris , Sangal Ashish , Powers Benjamin , Budd G Thomas , Victor Adrienne I , Hsueh Chung-Tsen , Chugh Rashmi , Nair Suresh , Leu Kirsten M , Agulnik Mark , Sharon Elad , Mayerson Edward , Plets Melissa , Blanke Charles , Streicher Howard , Chae Young Kwang , Kurzrock Razelle
Published: August 2021

Purpose

Angiosarcoma is a rare aggressive endothelial cell cancer with high mortality. Isolated reports suggest immune checkpoint inhibition efficacy in angiosarcoma, but no prospective studies have been published. We report results for angiosarcoma treated with ipilimumab and nivolumab as a cohort of an ongoing rare cancer study.

Methods

This is a prospective, open-label, multicenter phase II clinical trial of ipilimumab (1 mg/kg intravenously every 6 weeks) plus nivolumab (240 mg intravenously every 2 weeks) for metastatic or unresectable angiosarcoma. Primary endpoint was objective response rate (ORR) per RECIST 1.1. Secondary endpoints include progression-free (PFS) and overall survival, and toxicity. A two-stage design was used.

Results

Overall, there were 16 evaluable patients. Median age was 68 years (range, 25–81); median number of prior lines of therapy, 2. Nine patients had cutaneous and seven non-cutaneous primary tumors. ORR was 25% (4/16). Sixty per cent of patients (3/5) with primary cutaneous scalp or face tumors attained a confirmed response. Six-month PFS was 38%. Altogether, 75% of patients experienced an adverse event (AE) (at least possibly related to drug) (25% grade 3–4 AE); 68.8%, an immune-related AE (irAE) (2 (12.5%), grade 3 or 4 irAEs (alanine aminotransferase/aspartate aminotransferase increase and diarrhea)). There were no grade 5 toxicities. One of seven patients in whom tumor mutation burden (TMB) was assessed showed a high TMB (24 mutations/mb); that patient achieved a partial response (PR). Two of three patients with PDL1 immunohistochemistry assessed had high PDL1 expression; one achieved a PR.

Conclusion

The combination of ipilimumab and nivolumab demonstrated an ORR of 25% in angiosarcoma, with three of five patients with cutaneous tumors of the scalp or face responding. Ipilimumab and nivolumab warrant further investigation in angiosarcoma.

Trial registration number

NCT02834013.
Supporting the pursuit of professionalism during a crisis
Authors: Cooper William O , Lorenzi Nancy M , Davidson Heather A , Baldwin Cynthia A , Feinberg Daniel M , Hopkins Joseph , Spell Nathan O , Uthe Craig J , Hickson Gerald B
Published: August 2021

Background

Crisis plans for healthcare organisations most often focus on operational needs including staffing, supplies and physical plant needs. Less attention is focused on how leaders can support and encourage individual clinical team members to conduct themselves as professionals during a crisis.

Methods

This qualitative study analysed observations from 79 leaders at 160 hospitals that participate in two national professionalism programmes who shared their observations in focus group discussions about what they believed were the essential elements of leading and addressing professional accountability during a crisis.

Results

Analysis of focus group responses identified six leadership practices adopted by healthcare organisations, which were felt to be essential for organisations to navigate the crisis successfully. Unique aspects of maintaining professionalism during each phase of the pandemic were identified and described.

Conclusions

Leaders need a plan to support an organiation’s pursuit of professionalism during a crisis. Leaders participating in this study identified practices that should be carefully woven into efforts to support the ongoing safety and quality of the care delivered by healthcare organisations before, during and after a crisis. The lessons learnt from the COVID-19 pandemic may be useful during subsequent crises and challenges that a healthcare organisation might experience.
Periodontitis is associated to increased systemic inflammation in postmyocardial infarction patients
Authors: Lira-Junior Ronaldo , Boström Elisabeth Almer , Gustafsson Anders
Published: August 2021

Objective

Periodontitis has been independently associated to cardiovascular disease. However, the biological mechanisms underlying such association are still partially unknown. Thus, this study aimed to discover immunological clues accounting for the increased risk of myocardial infarction (MI) in patients having periodontitis.

Methods

We included 100 patients with a first MI, 50 with and 50 without severe periodontitis, and 100 age-matched, sex-matched and area-matched controls from the Periodontitis and Its Relation to Coronary Artery Disease Study. Participants underwent comprehensive clinical and laboratory examinations 6–10 weeks after the MI and plasma expression of 92 inflammation-related markers was assessed through proximity extension assay.

Results

Patients who had an MI displayed altered expression of CCL19, TNFRSF9 and LAP TGF-β1 in comparison with controls. TNFRSF9 correlated significantly with the amount of alveolar bone loss. MI patients with deep periodontal pockets showed increased white cell count and higher expression of FGF-21, HGF, OSM, CCL20 and IL-18R1 than patients without. White cell count correlated significantly with four of these proteins.

Conclusions

Collectively, our results indicate molecular markers that could be responsible for the increased systemic inflammatory activity in patients with MI with periodontitis.
Buprenorphine management in the perioperative period: educational review and recommendations from a multisociety expert panel
Authors: Kohan Lynn , Potru Sudheer , Barreveld Antje M , Sprintz Michael , Lane Olabisi , Aryal Anuj , Emerick Trent , Dopp Anna , Chhay Sophia , Viscusi Eugene
Published: August 2021

Background

The past two decades have witnessed an epidemic of opioid use disorder (OUD) in the USA, resulting in catastrophic loss of life secondary to opioid overdoses. Medication treatment of opioid use disorder (MOUD) is effective, yet barriers to care continue to result in a large proportion of untreated individuals. Optimal analgesia can be obtained in patients with MOUD within the perioperative period. Anesthesiologists and pain physicians can recommend and consider initiating MOUD in patients with suspected OUD at the point of care; this can serve as a bridge to comprehensive treatment and ultimately save lives.

Methods

The Board of Directors of the American Society of Regional Anesthesia and Pain Medicine, American Society of Anesthesiologists, American Academy of Pain Medicine, American Society of Addiction Medicine and American Society of Health System Pharmacists approved the creation of a Multisociety Working Group on Opioid Use Disorder, representing the fields of pain medicine, addiction, and pharmacy health sciences. An extensive literature search was performed by members of the working group. Multiple study types were included and reviewed for quality. A modified Delphi process was used to assess the literature and expert opinion for each topic, with 100% consensus being achieved on the statements and each recommendation. The consensus statements were then graded by the committee members using the United States Preventive Services Task Force grading of evidence guidelines. In addition to the consensus recommendations, a narrative overview of buprenorphine, including pharmacology and legal statutes, was performed.

Results

Two core topics were identified for the development of recommendations with >75% consensus as the goal for consensus; however, the working group achieved 100% consensus on both topics. Specific topics included (1) providing recommendations to aid physicians in the management of patients receiving buprenorphine for MOUD in the perioperative setting and (2) providing recommendations to aid physicians in the initiation of buprenorphine in patients with suspected OUD in the perioperative setting.

Conclusions

To decrease the risk of OUD recurrence, buprenorphine should not be routinely discontinued in the perioperative setting. Buprenorphine can be initiated in untreated patients with OUD and acute pain in the perioperative setting to decrease the risk of opioid recurrence and death from overdose.
Green Health in Guatemala: How can we build mutual trust and partnerships to develop an evidence-base for local medicines and realize their potential?
Authors: Berger-Gonzalez Monica , Scotti Francesca , Garcia Ana Isabel , Hesketh Alan , Hitziger Martin , Thompson Ian , Heinrich Michael
Published: August 2021

The implementation of access and benefit-sharing (ABS) protocols, and especially the Nagoya Protocol, has created new hurdles for international collaborations around Indigenous Traditional Knowledge. Overall, these frameworks push for the development of novel collaborative North–South agendas to improve the fair distribution of benefits. The Green Health Project (Guatemala) aims to implement a culturally pertinent and mutually accepted framework for sustainable use, as well as ABS of traditional medicinal plants. It involves developing a consensus among Indigenous groups, government officials, industry, and academia. We describe steps undertaken to design and implement an intercultural transdisciplinary process that promotes trust building and advances herbal medicine research in a respectful and innovative way. This involves joint definition of goals and methods. The consortium co-researched Q’eqchi’ Maya traditional medicine, collected voucher specimens of medicinal plants with traditional Healers, identified their taxa, and later developed a literature-based evaluation identifying species for potential product development. No samples for further research and development were collected. By applying the emic–etic concept, the project helped improve understanding of the main drivers of each stakeholder and the associated obstacles for reaching an ABS agreement. The project also explored the emergence of potential new drivers for developing evidence-based herbal medicine from the perspectives of academia, policy, cooperation, and grassroots Indigenous movements.
Biochar in temperate soils: opportunities and challenges
Authors: Lévesque Vicky , Oelbermann Maren , Ziadi Noura
Published: August 2021

Biochar, a carbon (C)-rich material produced by the pyrolysis of organic residues, is frequently used as a soil amendment to enhance soil fertility and improve soil properties in tropical climates. However, in temperate agriculture, the impact of biochar on soil and plant productivity remains uncertain. The objective of this review is to give an overview of the challenges and opportunities of using biochar as an amendment in temperate soils. Among the various challenges, the type of feedstock and the conditions during pyrolysis produces biochars with different chemical and physical properties, resulting in contrasting effects on soils and crops. Furthermore, biochar aging, biochar application rates, and its co-application with mineral fertilizer and (or) organic amendments add further complexity to our understanding of the soil-amendment-plant continuum. Although its benefits on crop yield are not yet well demonstrated under field studies, other agronomic benefits of biochar in temperate agriculture have been documented. In this review, we proposed a broader view of biochar as a temperate soil amendment, moving beyond our current focus on crop productivity, and instead target its capacity to improve soil properties. We explored biochar’s benefits in remediating low-productive agricultural lands and its environmental benefits through long-term C sequestration and reduced nutrient leaching while curtailing our reliance on fertilizer input. We also discussed the persistence of beneficial impacts of biochar in temperate field conditions. We concluded that biochar displays great prospective to improve soil health and its productivity, enhance plant stress resilience, mitigate greenhouse gas emissions, and restore degraded soils in temperate agriculture.