bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of Deformable Focusing Micromirrors
Authors: Yen Hanchee , Lee Chimin , Chen Rongshun , Lin Meng-Ju
Published: November 2021

A deformable mirror is an adaptive optical device that can deform its surface shape to self-adjust its focal length. This paper designed a center-anchored circular deformable micromirror, which is a two-layer structure; a metal layer atop a structure layer, fabricated using surface micromachining process and actuated by electrostatic force.

A series of simulations are performed to investigate the process- and voltage-induced deformations and thus to determine the focal length under various parameters for the designed micro-mirror. Because of warpage occurring after release, the two-layer center-anchored circular plate was cut into several sectors when fabricated, in which the diameters of the circular plate and the centric anchor are 500 (before deformation) and 100 μms, respectively. The profiles of deformable mirror are measured and the curvature radius measured is estimated from 200 to 400 μm.
Modeling and Optimization of a High Sensitivity Out-of-Plane Microgyroscope
Authors: Li Shifeng , Chen Shaochen
Published: November 2021

This paper presents an optimal model for microgyroscope design. According to gyroscope topology, one lumped dynamic model is built to optimise the microgyroscope performances. The design parameters are categorized into function variables and style variables to reduce optimisation cost. The maximum sensitivity and minimum area of the device are selected and weighted as the combined multiple objective functions. The optimisation is conducted with a solver in Excel9.5™. FEM is chosen to verify these optimised results. The FE results show good agreement with the model calculation. The discrepancy of mode shape is less than 5%. The discrepancy of sensitivity is less than 3%. The output linearity is less than 1.5%.
Characterizing the Poisson’s Ratio of Thin Films Using Resonance Method
Authors: Tsai Hsin-Chang , Lai Wen-Pin , Fang Weileun
Published: November 2021

In this study, we proposed a new and simple technique to characterize the Poisson’s ratio of thin films. The diagnostic micromachined cantilevers are fabricated using the thin film to be determined. The Poisson’s ratio of the thin film can be determined after the bending and torsional vibration modes are measured. To obtain cantilevers with prismatic cross section, the micromachined beams were fabricated on the (111) silicon substrate. The primary advantage of this technique is that the error of Poisson’s ratio due to the deviation of film thickness can be significantly reduced. In application of this technique, the Poisson’s ratio of thermally grown silicon dioxide is measured to be 0.26± 0.01.
Creation of Nanometer-Sized Features in Polysilicon Using Fusing
Authors: Levitan Jeremy A. , Good Dan , Sinclair Michael J. , Jacobson Joseph M.
Published: November 2021

Current microfabrication systems can achieve resolutions of approximately 0.1μm. We present physical methods for creating structures with length scales and characteristic dimensions significantly below current fabrication resolutions. These structures, themselves fabricated in conventional, gross-resolution (greater than 2μm) semiconductor facilities, undergo structural change to create features below the lithography limits of the fabrication process.

These devices — dog-boned microfabricated polysilicon fuses — are heated just below melting, and a small perturbation current heats a narrow, necked region of the beam, resulting in fusing.

Infrastructure has already been constructed to create gross-resolution structures in microfabrication. Novel processes and mechanisms are needed to utilize these resolutions and create structures capable of addressing biological systems, functioning quantum mechanically, use single electrons, or require extreme speeds.
Experimental Study on Roughness Effect for Laminar Micro-Channel Gas Flow
Authors: Tu Jih-Hsing , Tseng Fangang , Chieng Ching-Chang
Published: November 2021

Present study investigates the roughness effect on laminar gas flow for microchannels ranging from 40 to 600 μm with various roughness heights (40–82 nm) by systematical experiments. The micro-channels are manufactured by micro-machining technology and KOH anisotropic etching is employed to achieve various roughness patterns. Experimental results shows that higher product levels of Reynolds number (Reh) and friction factor (f) are obtained for microchannels of larger size and smaller relative roughness and friction factor f approaches to laminar flow theory value f0 for very smooth channel but the ratio of (f/f0) decreases as the surface roughness increases.
Instability Modes of Two-Phase Flows in a Mixing-Layer Microdevice
Authors: Yu Tak For , Lee Sylvanus Yuk Kwan , Zohar Yitshak , Wong Man
Published: November 2021

Extensive development of biomedical and chemical analytic microdevices involves microscale fluid flows. Merging of fluid streams is expected to be a key feature in such devices. An integrated microsystem consisting of merging microchannels and distributed pressure microsensors has been designed and characterized to study this phenomenon on a microscale. The two narrow, uniform and identical channels merged smoothly into a wide, straight and uniform channel downstream of a splitter plate. All of the devices were fabricated using standard micromachining techniques. Mass flow rates and pressure distributions were measured for single-phase gas flow in order to characterize the device. The experimental results indicated that the flow developed when both inlets were connected together to the gas source could be modeled as gas flow through a straight and uniform microchannel. The flow through a single branch while the other was blocked, however, could be modeled as gas flow through a pair of microchannels in series. Flow visualizations of two-phase flows have been conducted when driving liquid and gas through the inlet channels. Several instability modes of the gas/liquid interface have been observed as a function of the pressure difference between the two streams at the merging location.
Micropump Design for Optimum Pressure/Flow Characteristics
Authors: Williams Brian E. , Forster Fred K.
Published: November 2021

Until now there have been no reports of design techniques that include a means for developing pumps that can pump against higher pressure loads at the cost of less volume flow rate delivered to the load or vice versa. We address this problem for membrane micropumps that incorporate no-moving-parts valves (NMPV). A design approach is presented that utilizes a linear low-order model, finite element analysis to optimize piezoelectric actuation, and an algorithm to interrogate a design space of membrane thickness and valve size for any specified pressure load. The results indicate that optimum designs are relatively far from existing pumps and that significant improvements are possible. These gains appear to be due to the ability of the design approach to select non-obvious combinations of membrane stiffness and valve size to better “tune” the system, which is crucial in the case of NMPV pump, because excellent resonant behavior can make up for the fact that the valves do not open and close. Another important observation was that the optimal design point for pressure was not the same as for flow. This result is an indication that pumps can be designed for pressure or flow through careful design.
Precision Alignment Packaging for Microsystems With Multiple Fluid Connections
Authors: Galambos Paul , Benavides Gilbert L. , Okandan Murat , Jenkins Mark W. , Hetherington Dale
Published: November 2021

The application of microfluidic Microsystems to solve real world problems depends on effective packaging techniques. In this paper, we report on packaging methods that allow the connection of multiple fluid lines to a microfluidic chip. Eight different fluid connections are made in a 5 mm square area (100 connections possible) using a flip chip aligner/bonder with precise alignment on the order of 10 microns between holes (1 micron precision possible). The critical fluid connections are made using 0.002 inch thick double sided adhesive tape and are shown to hold greater than 20 atm of pressure without leaking. The packaging flow manifold and assembly methods are suitable for inexpensive mass production and are compatible with existing electronics packaging technologies.
Design, Fabrication, and Testing of a Continuous Flow, Submicroliter Scale PCR for the Analysis of Plant Genomes
Authors: Zheng Wei , Chen Shaochen
Published: November 2021

In recent years, many micromachined polymerase chain reaction (PCR) chips have been reported. These miniaturized PCR chips have great advantages such as the significant reduction in reagent costs and vastly reduced reaction times over the conventional PCR reactions. In this paper a micro analysis system that will allow submicro-liter scale, continuous-flow PCR to be conducted in a glass chip has been presented. This glass chip is fabricated through thermally bonding two pyrex 7740 glass wafers. One pyrex wafer is etched to form the 20-cycle microchannel with 80 microns wide and 30 microns deep. Another pyrex wafer is thermally bonded to the etched wafer to produce closed a continuous microchannel for PCR. The total length of the microchannel is 0.5 m. This PCR chip has a significant reagent reduction with a volume of less than 1 micro-liter. With 1 micro-liter reagent we obtain a total reaction time of 0.5 min to 3 min depending on various flow rates. This analytical chip is fabricated using standard micromachining techniques with a total size of 56 mm × 24 mm × 1 mm. The advantages of this chip include very small quantities of reagent needed, rapid thermal cycling, standard micromachining processes and batch fabrication which result in a significant cost reduction.
Design and Analysis of a Miniature Rotary Wankel Compressor
Authors: Finger G. W. , Kapat J. S. , Chow L. C.
Published: November 2021

Design and analysis of a meso-scale rotary Wankel compressor is presented here. The compressor is primarily designed for a hand-held power generation system, based on a modified Brayton cycle and capable of producing 20 W with a specific energy of 2400 to 3800 W-hr/kg for usage duration of 72 to 240 hours. The small size of the overall system makes the conventional design rules and concepts inappropriate, thus requiring new design concepts for the compressor and other components.

In the current design, the major axis of the epitrochoid is 14 mm. The three-lobed rotor is driven by a drive shaft through an internal gear system such that each revolution of the rotor corresponds to 3 revolutions of the drive shaft and 6 compression “strokes”. There are two intake ports and two discharge ports. The valves within these ports operate to limit the pressure ratio to 2.5, the target of the design. Rotor thickness is 9.1 mm and at a rotational speed of 5000 rpm, the compressor can provide a flow rate of 0.138 g/s air, as needed by the power generation system.

The pressure ratio of the compressor is a function of geometry (not rotor speed), and hence this design is well-suited for load following in a variable load application. Its drive shaft can be de-coupled from other system components of the power generation system. This mechanical isolation can lead to thermal isolation, which is essential for miniature power generation devices.

Micro-stereo lithography and micro-EDM appear to be the best methods to fabricate the necessary components of the compressor. Micro-stereo lithography, in particular, can provide a seamlessly integrated compressor, thus reducing the integration and assembly cost. Micro-EDM is more suited for production of large batch sizes because of the relatively high initial cost. More sophisticated micro-fabrication methods such as LIGA, UV-LIGA and lithography SU-8 can also be used. However, since the device thickness is rather large compared to what is typically done with these methods, multiple layers need to be bonded in both of these approaches because of the large thickness of the proposed design.
Resound: A Full Spectrum Modelling Method
Authors: Shorter P. J. , Gardner B. K. , Patil A.
Published: November 2021

The response of a structural-acoustic system in the mid-frequency range typically consists of both long and short wavelength behavior. Modeling the short-wavelength behavior deterministically is usually computationally prohibitive and structural-acoustic techniques such as SEA are often adopted. However, SEA cannot adequately capture the long-wavelength global behavior of the system. Recent work aimed at addressing the mid-frequency problem has led to the development of a hybrid approach based on a wavenumber partitioning scheme [1]. This paper provides an overview of the approach and presents some recent research developments.
Design and Optimization of Broadband Vibration Absorbers for Noise Control
Authors: Heinze Emily S. , Grissom Michael D. , Belegundu Ashok
Published: November 2021

A general and practical approach is presented for optimizing structural additions to a base structure for broadband dynamic objectives when the base structure is excited by an arbitrary forcing function. The mode shapes and natural frequencies of the base structure are first found using a commercial finite element code or an experimental modal analysis. The mode shapes are used as basis shapes to reduce the size of the equations. The structural additions are then added as impedances into the reduced modal model. An efficient analysis algorithm is presented to reduce the computational burden for broadband analysis and optimization loops. The power transferred into a Broadband Vibration Absorber (BBVA) from a base structure is maximized as an example application. The numerical results are experimentally verified demonstrating the practical design capabilities of the method.
High-Order Optimized Numerical Schemes for Computational Aeroacoustics
Authors: Zheng S. , Zhuang M.
Published: November 2021

This paper presents a new optimization approach for the high-order finite difference schemes. Due to the fact that it is common for a sound field to consist of several dominant wavenumbers, the proposed numerical schemes are optimized at these dominant wavenumbers instead of over a range of wavenumber. These optimized multi-component schemes, as referred to in this paper, give very accurate solutions if used to predict an acoustic wave traveling with these dominant wavenumbers. In addition, for broadband waves, it is shown that the performance of the optimized upwind multi-component scheme is comparable to that of the optimized upwind broadband scheme, which is optimized over a range of wavenumber. The results of the Fourier analysis also show that the optimized central multi-component schemes are at least comparable to if not better than the optimized central broadband schemes when solving broadband waves.
Siting and Safety Associated With a Municipal Skate Park
Authors: Pyatt D. W.
Published: November 2021

The town of Mount Airy, MD chose to construct a skateboard and roller blade park in 1998 because of the many young adults skating on parking lots, streets, and sidewalks within the Town Limits. Many citizens and merchants complained of hazards both to the young adults as well as to pedestrians and drivers. Several sites were selected for evaluation; the final site selection was an existing Town Park. The next step was to design the Skate Park to satisfy both the recreational needs and safety of skaters of all ages and skill levels. In this capacity, the author worked with skating groups, including professional skaters, and insurance experts who insured the Town’s facilities. A design was made, submitted for bids, and constructed in October 1999. The Skate Park has operated safely in the past year and has won recognition as a skater’s park. This paper will discuss how this was accomplished.
The Role of the Engineer in 21st Century Industry
Authors: Koenig Daniel T.
Published: November 2021

1. What you think of as the traditional role of the engineer in Industry no longer exists.

2. Engineers no longer occupy purely technical positions.

3. There are more engineers in traditionally nontechnical positions than in structured Design, Mfg. Engineering, and R&D positions.

4. These facts are not discipline specific, but true across the board for all types of Engineering.

5. This means that how we prepare engineers for their first jobs and how we continue to learn, or as Dick Golstein says, how we engage in life long learning is undergoing radical change.

6. The fact is engineers in industry are pragmatic technically trained business persons, not technologists or scientist and we need to recognize that basic truth.

7. Now, with this as the state of the engineers position in industry, I’d like to discuss the changing nature of the strategy of operations that the engineer has to contend with and the education needs to support that strategy.
Bioengineering: From Mechanics and Devices to Tissue Engineering and Genetics
Authors: Phillips Winfred M.
Published: November 2021

The National Institutes of Health (NIH) defines bioengineering as an interdisciplinary field that applies physical, chemical, and mathematical sciences and engineering principles to the study of biology, medicine, behavior, and health. Bioengineering advances knowledge from the molecular to the organ systems level, and develops new and novel biologics, materials, processes, implants, devices, and informational approaches for the prevention, diagnosis, and treatment of disease, for patient rehabilitation, and for improving health.

Enormous contributions to the advancement of health care have been made through bioengineering. It has been instrumental in establishing the United States as the world leader in health care technology, as evidenced by a $4.6 billion trade surplus for this sector in 1993. The field, through basic and applied research and technology assessment, has given us such devices as the pacemaker, orthopedic implants, and noninvasive diagnostic imaging. Bioengineers have developed new processes for manufacturing products in the pharmaceutical and biotechnology industries. An example is the manufacturing of human insulin, the first product based on recombinant DNA technology, where bioengineering was critical to the ability to commercialize the product.

These continuing contributions and unprecedented growth, focus, and opportunity in bioengineering will be a continuing frontier and opportunity for the United States and the world.
Microsensors, MEMS and NEMS Based Complex Adaptive Smart Devices and Systems
Authors: Varadan Vijay K.
Published: November 2021

The microelectronics industry has seen explosive growth during the last thirty years. Extremely large markets for logic and memory devices have driven the development of new materials, and technologies for the fabrication of even more complex devices with features sizes now down at the sub micron level. Recent interest has arisen in employing these materials, tools and technologies for the fabrication of miniature sensors and actuators and their integration with electronic circuits to produce smart devices and MicroElectroMechanical Systems (MEMS). This effort offers the promise of:

1. Increasing the performance and manufacturability of both sensors and actuators by exploiting new batch fabrication processes developed for the IC and microelectronics industry. Examples include micro stereo lithographic and micro molding techniques.

2. Developing novel classes of materials and mechanical structures not possible previously, such as diamond like carbon, silicon carbide and carbon nanotubes, micro-turbines and micro-engines.

3. Development of technologies for the system level and wafer level integration of micro components at the nanometer precision, such as self-assembly techniques and robotic manipulation.

4. Development of control and communication systems for MEMS devices, such as optical and RF wireless, and power delivery systems.
Sound source localization based on multi-task learning and image translation network
Authors: Wu Yifan , Ayyalasomayajula Roshan , Bianco Michael J. , Bharadia Dinesh , Gerstoft Peter
Published: November 2021

Supervised learning-based sound source localization (SSL) methods have been shown to achieve a promising localization accuracy in the past. In this paper, MTIT, SSL for indoors using Multi-Task learning and Image Translation network, an image translation-based deep neural networks (DNNs) framework for SSL is presented to predict the locations of sound sources with random positions in a continuous space. We extract and represent the spatial features of the sound signals as beam response at each direction which can indicate the chance of the source in each point of the room. We utilize the multi-task learning (MTL) based training framework. There are one encoder and two decoders in our DNN. The encoder aims to obtain a compressed representation of the input beamspectrum surfaces while the two decoders focus on two tasks in parallel. One decoder focuses on resolving the multipath caused by reverberation and the other decoder predicts the source location. Since these two decoders share the same encoder, by training these two decoders in parallel, the shared representations are refined. We comprehensively evaluate the localization performance of our method in the simulated data, measured impulse response and real recordings datasets and compare it with multiple signal classification, steered response power with phase transform, and a competing convolutional neural network approach. It turns out that MTIT can outperform all of the baseline methods in a dynamic environment and also can achieve a good generalization performance.
Experiences of Playing Volt Hockey With Focus on Well-Being According to Positive Emotion, Engagement, Relationships, Meaning, Achievement: An Interview Study
Authors: Aho Anna Carin , Renmarker Elisabeth , Axelsson Malin , Jakobsson Jenny
Published: November 2021

Volt hockey is a team sport developed for persons with physical disabilities, but its influence on well-being is unknown. Elements of well-being have been described as positive emotions, engagement, relationships, meaning, and achievement constituting a theoretical framework referred to as PERMA. The purpose of this study was to describe how well-being according to PERMA is reflected in the experiences of playing volt hockey. Data were collected through focus group and individual interviews including 21 players. A deductive analysis was conducted using the elements in PERMA as preexisting main categories with an additional main category, named resources needed. Findings showed that all five elements constituting well-being according to PERMA were reflected in the experiences of playing volt hockey. In addition, players emphasized the importance of having the resources needed to play volt hockey. In conclusion, having the opportunity to enjoy playing volt hockey enabled the players to flourish and experience feelings of subjective well-being.
Clathrin-coated structures support 3D directed migration through local force transmission
Authors: Bresteau Enzo , Elkhatib Nadia , Baschieri Francesco , Bellec Karen , Guérin Mélanie , Montagnac Guillaume
Published: November 2021

Adhesive clathrin-coated structures steer cell migration by accumulating on collagen fibers decorated with specific ligands.
Modulating the pro-apoptotic activity of cytochrome c at a biomimetic electrified interface
Authors: Gamero-Quijano Alonso , Bhattacharya Shayon , Cazade Pierre-André , Molina-Osorio Andrés F. , Beecher Cillian , Djeghader Ahmed , Soulimane Tewfik , Dossot Manuel , Thompson Damien , Herzog Grégoire , Scanlon Micheál D.
Published: November 2021

An electrified aqueous-organic interface modulates the conformational plasticity of the protein cytochrome c.
Networks of habenula-projecting cortical neurons regulate cocaine seeking
Authors: Mathis Victor P. , Williams Maya , Fillinger Clementine , Kenny Paul J.
Published: November 2021

Cortical neurons that project to habenula then locus coeruleus regulate cocaine relapse.
Solar plus batteries is now cheaper than fossil power
Authors: Service Robert F.
Published: November 2021

Falling prices help utilities start to decarbonize.
Enhanced CAR–T cell activity against solid tumors by vaccine boosting through the chimeric receptor
Authors: Ma Leyuan , Dichwalkar Tanmay , Chang Jason Y. H. , Cossette Benjamin , Garafola Daniel , Zhang Angela Q. , Fichter Michael , Wang Chensu , Liang Simon , Silva Murillo , Kumari Sudha , Mehta Naveen K. , Abraham Wuhbet , Thai Nikki , Li Na , Wittrup K. Dane , Irvine Darrell J.
Published: November 2021

A boost for CAR–T cells

Chimeric antigen receptor (CAR)–T cell immunotherapy has been highly successful for treating certain blood cancers. Yet this approach has been a challenge for solid tumors, in part because it is difficult to target functional engineered T cells to the tumor site. Ma
et al.
designed a vaccine strategy to improve the efficacy of CAR–T cells by restimulating the CAR directly within the native lymph node microenvironment (see the Perspective by Singh and June). Injected “amph-ligand” vaccines promoted synthetic antigen presentation and led to CAR–T cell activation, expansion, and increased tumor killing. The system could potentially be applied to boost any CAR–T cell.

Science
, this issue p.
162
; see also p.
119
Sheath-run artificial muscles
Authors: Mu Jiuke , Jung de Andrade Mônica , Fang Shaoli , Wang Xuemin , Gao Enlai , Li Na , Kim Shi Hyeong , Wang Hongzhi , Hou Chengyi , Zhang Qinghong , Zhu Meifang , Qian Dong , Lu Hongbing , Kongahage Dharshika , Talebian Sepehr , Foroughi Javad , Spinks Geoffrey , Kim Hyun , Ware Taylor H. , Sim Hyeon Jun , Lee Dong Yeop , Jang Yongwoo , Kim Seon Jeong , Baughman Ray H.
Published: November 2021

Getting the most out of muscles

Materials that convert electrical, chemical, or thermal energy into a shape change can be used to form artificial muscles. Such materials include bimetallic strips or host-guest materials or coiled fibers or yarns (see the Perspective by Tawfick and Tang). Kanik
et al.
developed a polymer bimorph structure from an elastomer and a semicrystalline polymer where the difference in thermal expansion enabled thermally actuated artificial muscles. Iterative cold stretching of clad fibers could be used to tailor the dimensions and mechanical response, making it simple to produce hundreds of meters of coiled fibers. Mu
et al.
describe carbon nanotube yarns in which the volume-changing material is placed as a sheath outside the twisted or coiled fiber. This configuration can double the work capacity of tensile muscles. Yuan
et al.
produced polymer fiber torsional actuators with the ability to store energy that could be recovered on heating. Twisting mechanical deformation was applied to the fibers above the glass transition temperature and then stored via rapid quenching.

Science
, this issue p.
145
, p.
150
, p.
155
; see also p.
125
Seabird clues to ecosystem health
Authors: Velarde Enriqueta , Anderson Daniel W. , Ezcurra Exequiel
Published: November 2021

Seabird monitoring provides essential information on the state of marine ecosystems
Molecular structure elucidation with charge-state control
Authors: Fatayer Shadi , Albrecht Florian , Zhang Yunlong , Urbonas Darius , Peña Diego , Moll Nikolaj , Gross Leo
Published: November 2021

Visualizing molecular charging

High-resolution atomic force microscopy (AFM) has been used to control and image the charge state of organic molecules adsorbed on multilayer sodium chloride films. Fatayer
et al.
biased an AFM probe tip with a voltage to charge and discharge molecules such as azobenzene and porphine from cations to anions. Subsequent imaging with carbon monoxide–functionalized tips revealed changes in the conformation, bond order, and aromaticity of the organic molecules resulting from charge-state changes.

Science
, this issue p.
142
Paneth cell dysfunction and the intestinal microbiome in XIAP deficiency
Authors: Azabdaftari Aline , Uhlig Holm H.
Published: November 2021

New data suggest how epithelial dysfunction and intestinal dysbiosis contribute to inflammatory bowel disease in patients and in models of XIAP deficiency (see the related Research Articles by

Strigli
et al
.

and

Wahida
et al
.

).
Supplemental Material: Zircon (U-Th)/He thermochronology of Grand Canyon resolves 1250 Ma unroofing at the Great Unconformity and <20 Ma canyon carving
Authors: Thurston Olivia G. , al. et
Published: November 2021

All geologic and thermochronologic constraints used in the forward models, major forward model results from the zircon radiation damage accumulation and annealing model (ZRDAAM) of Guenthner et al. (2013), and alternative HeFTy forward model result using different sample inputs.
Supplemental Material: Monthly insolation linked to the time-transgressive nature of the Holocene East Asian monsoon precipitation maximum
Authors: Zhou Xin , al. et
Published: November 2021

Supplemental information on the records used, the chronological framework of different sites, reconstructions of precipitation changes, and the defined time of the Holocene monsoon precipitation maximum.
Latest Permian–Triassic magmatism of the Taimyr Peninsula: New evidence for a connection to the Siberian Traps large igneous province
Authors: Kurapov Mikhail , Ershova Victoria , Khudoley Andrei , Luchitskaya Marina , Stockli Daniel , Makariev Alexander , Makarieva Elena , Vishnevskaya Irina
Published: November 2021

This study presents new whole rock major and trace element, Sr-Nd isotopic, petrographic, and geochronologic data for seven latest Permian (Changhsingian)–Late Triassic (Carnian) granitoid intrusions of the northwestern and northeastern Taimyr Peninsula in the Russian High Arctic. U-Pb zircon ages, obtained using secondary ion mass spectrometry (SIMS), sensitive high-resolution ion microprobe (SHRIMP), and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), define the crystallization age of the Taimyr intrusions studied as ranging from ca. 253 Ma to 228 Ma, which suggests two magmatic pulses of latest Permian–Early Triassic and Middle–Late Triassic age. Ar-Ar dating of biotite and amphibole indicate rapid cooling of the intrusions studied, but Ar-Ar ages of several samples were reset by secondary heating and hydrothermal activity induced by the Middle–Late Triassic magmatic pulse. Petrographic data distinguish two groups of granites: syenite–monzonites and granites–granodiorites. Sr-Nd isotopic data, obtained from the same intrusions, show a variation of initial (87Sr/86Sr)i ratios between 0.70377 and 0.70607, and εNd(t) values range between –6.9 and 1.2. We propose that the geochemical and isotopic compositions of the Late Permian–Triassic Taimyr granites record the existence of a magma mush zone that was generated by the two pulses of Siberian Traps large igneous province (LIP) magmatism.
General population screening for childhood type 1 diabetes: is it time for a UK strategy?
Authors: Besser Rachel Elizabeth Jane , Ng Sze May , Gregory John W , Dayan Colin M , Randell Tabitha , Barrett Timothy
Published: November 2021

Type 1 diabetes (T1D) is a chronic autoimmune disease of childhood affecting 1:500 children aged under 15 years, with around 25% presenting with life-threatening diabetic ketoacidosis (DKA). While first-degree relatives have the highest risk of T1D, more than 85% of children who develop T1D do not have a family history. Despite public health awareness campaigns, DKA rates have not fallen over the last decade. T1D has a long prodrome, and it is now possible to identify children who go on to develop T1D with a high degree of certainty. The reasons for identifying children presymptomatically include prevention of DKA and related morbidities and mortality, reducing the need for hospitalisation, time to provide emotional support and education to ensure a smooth transition to insulin treatment, and opportunities for new treatments to prevent or delay progression. Research studies of population-based screening strategies include using islet autoantibodies alone or in combination with genetic risk factors, both of which can be measured from a capillary sample. If found during screening, the presence of two or more islet autoantibodies has a high positive predictive value for future T1D in childhood (under 18 years), offering an opportunity for DKA prevention. However, a single time-point test will not identify all children who go on to develop T1D, and so combining with genetic risk factors for T1D may be an alternative approach. Here we discuss the pros and cons of T1D screening in the UK, the different strategies available, the knowledge gaps and why a T1D screening strategy is needed.
Secular trends in early motor development between 1980 and 2010 in Japan
Authors: Yoshii Keisuke , Michihata Nobuaki , Hirasawa Kyoko , Nagata Satoru , Morisaki Naho
Published: November 2021

Objective

Recent changes in birth characteristics in Japan may have a potential influence on children’s developments. Therefore, we investigated secular trends in gross motor milestones.

Design

Data were collected from an official Japanese nationwide serial cross-sectional survey conducted every 10 years since 1960. 22 320 participants aged 2–18 months were identified from the four surveys from 1980 to 2010.

Outcomes

We assessed whether or not a child achieved four gross motor milestones including rolling over (rolling), sitting without support (sitting), standing with support (standing) and walking alone (walking). The target age was defined as the age when the attainment rate ranged from >5% to >95% of the total. Multivariate logistic regression models were fitted.

Results

The final cohort included 20 570 children. The target ages were determined as follows: 3–6 months for rolling; 5–9 months for sitting; 6–11 months for standing; and 9–15 months for walking. The attainment rates of sitting, standing and walking in 1990 were higher than those in 2010, even after adjusting for child characteristics (sitting: adjusted OR (aOR)=2.07 (95% CI 1.62 to 2.65); standing: aOR=1.63 (95% CI 1.32 to 2.02); and walking: aOR=1.61 (95% CI 1.34 to 1.95)).

Conclusions

The proportion of children who attained three motor milestones (sitting, standing and walking) by set target ages decreased between 1990 and 2010. The contribution of birth characteristics including a decrease in gestational age and fetal growth, as well as changes in other child characteristics, failed to explain why this decrease occurred.
Evaluation of a contactless neonatal physiological monitor in Nairobi, Kenya
Authors: Wang Dee , Macharia William M , Ochieng Roseline , Chomba Dorothy , Hadida Yifat S , Karasik Roman , Dunsmuir Dustin , Coleman Jesse , Zhou Guohai , Ginsburg Amy Sarah , Ansermino J Mark
Published: November 2021

Background

Globally, 2.5 million neonates died in 2018, accounting for 46% of under-5 deaths. Multiparameter continuous physiological monitoring (MCPM) of neonates allows for early detection and treatment of life-threatening health problems. However, neonatal monitoring technology is largely unavailable in low-resource settings.

Methods

In four evaluation rounds, we prospectively compared the accuracy of the EarlySense under-mattress device to the Masimo Rad-97 pulse CO-oximeter with capnography reference device for heart rate (HR) and respiratory rate (RR) measurements in neonates in Kenya. EarlySense algorithm optimisations were made between evaluation rounds. In each evaluation round, we compared 200 randomly selected epochs of data using Bland-Altman plots and generated Clarke error grids with zones of 20% to aid in clinical interpretation.

Results

Between 9 July 2019 and 8 January 2020, we collected 280 hours of MCPM data from 76 enrolled neonates. At the final evaluation round, the EarlySense MCPM device demonstrated a bias of −0.8 beats/minute for HR and 1.6 breaths/minute for RR, and normalised spread between the 95% upper and lower limits of agreement of 6.2% for HR and 27.3% for RR. Agreement between the two MCPM devices met the a priori–defined threshold of 30%. The Clarke error grids showed that all observations for HR and 197/200 for RR were within a 20% difference.

Conclusion

Our research indicates that there is acceptable agreement between the EarlySense and Masimo MCPM devices in the context of large within-subject variability; however, further studies establishing cost-effectiveness and clinical effectiveness are needed before large-scale implementation of the EarlySense MCPM device in neonates.

Trial registration number

NCT03920761.
Even low doses of steroids increase the risk of cardiovascular disease in people with inflammatory diseases
Authors: Saul Helen , Gursul Deniz
Published: November 2021

The study

Pujades-Rodríguez M, Morgan AW, Cubbon RM, Wu J. Dose-dependent oral glucocorticoid cardiovascular risks in people with immune-mediated inflammatory diseases: a population-based cohort study.
PLoS Med
2020;17:e1003432.

To read the full NIHR Alert, go to:
https://evidence.nihr.ac.uk/alert/low-doses-steroids-increase-cardiovascular-risks-in-inflammatory-diseases/
Power analysis in health policy and systems research: a guide to research conceptualisation
Authors: Topp Stephanie M , Schaaf Marta , Sriram Veena , Scott Kerry , Dalglish Sarah L , Nelson Erica Marie , SR Rajasulochana , Mishra Arima , Asthana Sumegha , Parashar Rakesh , Marten Robert , Costa João Gutemberg Quintas , Sacks Emma , BR Rajeev , Reyes Katherine Ann V , Singh Shweta
Published: November 2021

Power is a growing area of study for researchers and practitioners working in the field of health policy and systems research (HPSR). Theoretical development and empirical research on power are crucial for providing deeper, more nuanced understandings of the mechanisms and structures leading to social inequities and health disparities; placing contemporary policy concerns in a wider historical, political and social context; and for contributing to the (re)design or reform of health systems to drive progress towards improved health outcomes. Nonetheless, explicit analyses of power in HPSR remain relatively infrequent, and there are no comprehensive resources that serve as theoretical and methodological starting points. This paper aims to fill this gap by providing a consolidated guide to researchers wishing to consider, design and conduct power analyses of health policies or systems. This practice article presents a synthesis of theoretical and conceptual understandings of power; describes methodologies and approaches for conducting power analyses; discusses how they might be appropriately combined; and throughout reflects on the importance of engaging with positionality through reflexive praxis. Expanding research on power in health policy and systems will generate key insights needed to address underlying drivers of health disparities and strengthen health systems for all.
Ethnic minority status as social determinant for COVID-19 infection, hospitalisation, severity, ICU admission and deaths in the early phase of the pandemic: a meta-analysis
Authors: Agyemang Charles , Richters Anke , Jolani Shahab , Hendriks Stevie , Zalpuri Saurabh , Yu Evan , Pijls Bart , Prins Maria , Stronks Karien , Zeegers Maurice P
Published: November 2021

Introduction

Early literature on the COVID-19 pandemic indicated striking ethnic inequalities in SARS-CoV-2-related outcomes. This systematic review and meta-analysis aimed to describe the presence and magnitude of associations between ethnic groups and COVID-19-related outcomes.

Methods

PubMed and Embase were searched from December 2019 through September 2020. Studies reporting extractable data (ie, crude numbers, and unadjusted or adjusted risk/ORs) by ethnic group on any of the five studied outcomes: confirmed COVID-19 infection in the general population, hospitalisation among infected patients, and disease severity, intensive care unit (ICU) admission and mortality among hospitalised patients with SARS-CoV-2 infection, were included using standardised electronic data extraction forms. We pooled data from published studies using random-effects meta-analysis.

Results

58 studies were included from seven countries in four continents, mostly retrospective cohort studies, covering a total of almost 10 million individuals from the first wave until the summer of 2020. The risk of diagnosed SARS-CoV-2 infection was higher in most ethnic minority groups than their White counterparts in North American and Europe with the differences remaining in the US ethnic minorities after adjustment for confounders and explanatory factors. Among people with confirmed infection, African-Americans and Hispanic-Americans were also more likely than White-Americans to be hospitalised with SARS-CoV-2 infection. No increased risk of COVID-19 outcomes (ie, severe disease, ICU admission and death) was found among ethnic minority patients once hospitalised, except for a higher risk of death among ethnic minorities in Brazil.

Conclusion

The risk of SARS-CoV-2 diagnosis was higher in most ethnic minorities, but once hospitalised, no clear inequalities exist in COVID-19 outcomes except for the high risk of death in ethnic minorities in Brazil. The findings highlight the necessity to tackle disparities in social determinants of health, preventative opportunities and delay in healthcare use. Ethnic minorities should specifically be considered in policies mitigating negative impacts of the pandemic.

PROSPERO registration number

CRD42020180085.
Efficacy of a glucagon-like peptide-1 agonist and restrictive versus liberal oxygen supply in patients undergoing coronary artery bypass grafting or aortic valve replacement: study protocol for a 2-by-2 factorial designed, randomised clinical trial
Authors: Wiberg Sebastian , Kjaergaard Jesper , Møgelvang Rasmus , Møller Christian Holdflod , Kandler Kristian , Ravn Hanne , Hassager Christian , Køber Lars , Nilsson Jens Christian
Published: November 2021

Introduction

Coronary artery bypass grafting (CABG) and/or aortic valve replacement (AVR) are associated with risk of death, as well as brain, heart and kidney injury. Glucagon-like peptide-1 (GLP-1) analogues are approved for treatment of type 2 diabetes, and GLP-1 analogues have been suggested to have potential organ-protective and anti-inflammatory effects. During cardiopulmonary bypass (CPB), consensus on the optimal fraction of oxygen is lacking. The objective of this study is to determine the efficacy of the GLP-1-analogue exenatide versus placebo and restrictive oxygenation (50% fractional inspired oxygen, FiO2) versus liberal oxygenation (100% FiO2) in patients undergoing open heart surgery.

Methods and analysis

A randomised, placebo-controlled, double blind (for the exenatide intervention)/single blind (for the oxygenation strategy), 2×2 factorial designed single-centre trial on adult patients undergoing elective or subacute CABG and/or surgical AVR. Patients will be randomised in a 1:1 and 1:1 ratio to a 6-hour and 15 min infusion of 17.4 µg of exenatide or placebo during CPB and to a FiO2 of 50% or 100% during and after weaning from CPB. Patients will be followed until 12 months after inclusion of the last participant. The primary composite endpoint consists of time to first event of death, renal failure requiring renal replacement therapy, hospitalisation for stroke or heart failure. In addition, the trial will include predefined sub-studies applying more advanced measures of cardiac- and pulmonary dysfunction, renal dysfunction and cerebral dysfunction. The trial is event driven and aims at 323 primary endpoints with a projected inclusion of 1400 patients.

Ethics and dissemination

Eligible patients will provide informed, written consent prior to randomisation. The trial is approved by the local ethics committee and is conducted in accordance with Danish legislation and the Declaration of Helsinki. The results will be presented in peer-reviewed journals.

Trial registration number

NCT02673931.
Extraocular muscle resection, recession length and surgery outcome modelling in strabismus treatment: a pilot study
Authors: Paduca Ala , Arnaut Oleg , Bendelic Eugeniu , Bruenech Jan Richard , Lundmark Per Olof
Published: November 2021

Background

Many surgical formulas have been developed and proposed based on the experience of surgeons to improve the predictability of strabismus surgery. However, the consent among strabismus surgeons regarding the dose effect of the extraocular muscle (EOM) recession or resection was not achieved yet and the disagreement about the appropriate amount of strabismus surgery still exists.

Objective

Our study aimed to propose an instrument for EOM resection (RsL) and recession length (RcL) estimation before the surgery and second to elaborate an postoperative angle of deviation (PAD) predictive model using simple potential predictors.

Methods and Analysis

The analytical prospective clinical study was conducted from April 2016 to July 2019, on a sample of 216 patients (aged between 2–58) with concomitant strabismus who underwent strabismus surgery in Clinical Republican Hospital ‘Timofei Mosneaga’and Children Hospital ‘Em Cotaga’ from Republic of Moldova. The correlations of patients’ age, strabismus type, amblyopia degree, RsL, RcL, preoperative angle of deviation (PreAD) with PAD were estimated using Pearson’s correlation analysis. Multiple linear regression analysis, multicollinearity analysis and residual analysis were performed.

Results

The EOM RsL was predicted using strabismus type, patient’s age, PreAD and EOM RcL. EOM RcL, in turn, was estimated by the similar covariates set, instead of RcL being RsL. PAD modelling showed the PreAD, EOM RsL and EOM RcL predictive ability for strabismus surgery outcome prediction.

Conclusion

In our study, we propose four mathematical models as potential instruments for EOM RsL, EOM RcL and PAD modelling in esotropia and exotropia surgery.
At risk child: a contemporary analysis of injured children in London and the South East of England: a prospective, multicentre cohort study
Authors: Elbourne Ceri , Cole Elaine , Marsh Stephen , Rex Dean , Makin Erica , Salter Rebecca , Brohi Karim , Edmonds Naomi , Cleeve Stewart , O'Neill Breda
Published: November 2021

Background

Injury is a leading health burden in children yet relatively little is reported about the contemporary risks they face. Current national registry data may under-represent the true burden of injury to children. We aim to analyse contemporary patterns of paediatric trauma and identify current factors putting children at risk of injury.

Methods

A 3-month prospective multicentre cohort evaluation of injured children across the London Major Trauma System was performed. All children receiving a trauma team activation; meeting National Institute for Health and Care Excellence CT head criteria; or admitted/transferred out due to trauma were included. Data were collected on demographics, mechanism and location of injury, and body region injured. The primary outcome was in-hospital mortality and secondary outcome was safeguarding concerns.

Results

659 children were included. Young children were more likely to be injured at home (0–5 years old: 70.8%, n=167 vs adolescents: 15.6%, n=31). Adolescents were more likely to be injured in the street (42.7%, n=85). Head trauma caused over half of injuries in 0–5 years old (51.9%, n=121). Falls were common and increasingly prevalent in younger children, causing 56.6% (n=372) of injuries. In adolescents, penetrating violence caused more than one in five injuries (21.9%, n=50). Most injured children survived (99.8%, n=658), however, one in four (26.1%, n=172) had safeguarding concerns and a quarter of adolescents had police, third sector or external agency involvement (23.2%, n=53).

Conclusions

This study describes modern-day paediatric trauma and highlights the variance in injury patterns in young children and adolescents. Importantly, it highlights differences in actual rates of injuries compared with those reported from current national registry data. We must understand real risks facing 21st century children to effectively safeguard future generations. The results provide an opportunity to reassess the current approach to injury prevention, child and adolescent safeguarding, and public health campaigns for child safety.