bluuebunny/crossref_metadata_2025 huggingface dataset:
High Energy Piping Walkdowns in Compliance With ASME B31.1
Authors: Cohn Marvin J. , Gialdini Robert J. , Nye Osborne B.
Published: October 2021

This paper discusses high energy piping (HEP) system walkdown requirements and guidelines in compliance with the American Society of Mechanical Engineers (ASME) B31.1 Code. Chapter VII states that the Operating Company shall develop and implement a program requiring documentation of piping support readings and recorded piping system displacements. Guidelines for this program are provided in Nonmandatory Appendix V, para. V-7. The Code also requires that the Operating Company shall evaluate the effects of unexpected piping position changes, significant vibrations, and malfunctioning supports on the piping system’s integrity and safety. These requirements and guidelines have been developed for personnel safety and piping system reliability.

The HEP system should be maintained to behave as expected in the original design analysis unless a field change is justified by qualified personnel. The walkdown program should be an integral part of an asset integrity management program, including observations, documentation, evaluations, corrective actions, and countermeasures.

A thorough HEP system walkdown includes more than documented hanger readings. It should include visual assessments of possible sagging pipe, unusual pipe slopes, building structure damage, lagging/insulation damage, locked spring hangers, piping interferences, damaged spring coils, loose/missing support fasteners, unloaded rigid supports, bent struts, insufficient hydraulic fluid in snubbers, detached Teflon strips on sliding supports, and confirmation that the current supports are consistent with the original design specifications. If accessible, it should be confirmed that there are no gaps in the sliding supports.

This paper illustrates that it is now possible to photographically document spring support position indicator readings from distances up to 30 feet (9.1 meters). Photographic documentation provides higher confidence in the position indicator readings and can resolve many visual documentation discrepancies, such as incorrect support readings, readings from opposite position indicator sides, and parallax issues. If accessible, closer inspections may confirm if a spring support is in fact internally bottomed-out or topped-out.

Nonmandatory Appendix V provides recommended hot walkdown and cold walkdown forms. These forms provide additional space for applicable notes. Example photographs of many piping system anomalies and associated documentation are provided in this paper. ASME B31.1 requires that significant displacement variations from the expected design displacements shall be considered to assess the piping system’s integrity.
Safety Justification Strategy for the Implementation of Additive Manufacture Small-Bore Globe Valves for Nuclear Plant
Authors: Press Bill , Dukes Adam , Poole Dave , Adams Jack , Burling Luke , Sulley John
Published: October 2021

The Additive Manufacture (AM) of nuclear plant components, such as small-bore globe valves, offers opportunities to reduce costs and improve production lead-times. Cost reductions can be achieved by reducing raw material quantities, removing machining operations, and eliminating the welding of sub-assemblies. Furthermore, there is the opportunity to reduce production lead-times by simplifying the supply chain, e.g. reducing the number of parts to be sourced and eliminating special operations. Such opportunities are important against a backdrop of industry striving to reduce the cost of nuclear power generation in order to ensure viability with other forms of power generation.

However, AM is a relatively new and innovative manufacturing technology, and although now seeing greater use in industry, there are still very few examples of where the technology has been applied to components used in safety critical applications. Furthermore, it is not covered by the American Society of Mechanical Engineers (ASME), Section III, nuclear design code. For nuclear plant applications, it is imperative a robust safety justification is provided.

This paper presents Rolls-Royce’s approach to provision of a high integrity safety justification to enable the implementation of AM small-bore globe valves, up to a nominal bore size of 2” to nuclear plant. The material of construction is AM Laser Powder Bed Fusion (LPBF) 316LN stainless steel, with a Hot Isostatic Press (HIP) bonded LPBF Tristelle 5183 low cobalt hard facing seat.

The paper describes the structure of the safety justification, which follows a multi-legged approach. It provides an overview of the innovative manufacturing process, which is, to the best of Rolls-Royce’s knowledge, the first of a kind application on nuclear pressure boundary components.

The paper provides a summary of the suite of materials testing and metallurgical examinations conducted, and majors on prototype functional and performance testing where comparisons are made with the previous forged form. Pressure testing is covered which includes ultimate pressure testing to 2,000 bar, as well as: functional cyclic testing, hard facing bond strength tests, dynamic loading (shock), and cyclic thermal tests. In all cases the additive manufactured small-bore globe valves performed as well, and in some cases better than the forged material equivalent.
Reliability of Ultrasonic Testing at Crack Fields in Large Forgings
Authors: Juengert Anne , Jacobs Oliver , Gauder Patrick , Weihe Stefan
Published: October 2021

There is a possibility that crack fields form in large forgings, if the chemical composition and the manufacturing conditions interact in an unfavorable way and lead to hydrogen flaking. Comparable crack fields were found for example during ultrasonic inspections in reactor pressure vessels of two Belgian nuclear power plants in 2012. In an ongoing research project, new approaches for the assessment of crack fields are developed. The investigation of the reliability of ultrasonic testing techniques for crack fields is also a part of this project. Ultrasonic testing (UT) took place at a test block containing a crack field. The test block was later cut into plates and test specimen for destructive material tests were manufactured. In addition to the ultrasonic testing, magnetic particle testing (MT) was applied at the cutting surfaces of the plates and radiographic testing (RT) was done at the plates. The sum of all nondestructive examinations lead to a data set, that is in general suitable for the calculation of probability of detection curves (PoD). MT and RT deliver crack locations and crack sizes that are compared to the UT results.

With the results, PoD curves are calculated for UT testing at the crack field. Due to shadowing and material damping, the PoD curves should become poorer for areas deeper in the crack field. The paper shows the results from a PoD calculation using a Hit/Miss-Analysis from experimental data. The limits of the technique are discussed as well. Additionally, the interaction for the detected flaws will be investigated as far as possible according to actual codes.
ASME Post Construction Standards: 25 Years of Progress
Authors: Rodery Clay D.
Published: October 2021

The ASME Post Construction Standards Committee was formed in 1995 in response to an identified need for recognized and generally accepted engineering practices for the inspection and maintenance of pressure equipment after it has been placed in service. In 2020, the Committee marked its 25th year since its inception. This paper provides an overview of the history of that journey. It begins with a review of how post construction activities were addressed in the past, and how requirements for inspection, maintenance and repair of pressure equipment were addressed up until the early 1990s. It then chronicles the ASME activities from the formation of an ad-hoc task group through the formation of the committee, the identification of areas where standards were needed, and the publication of post construction standards within its scope. The paper also provides an overview of the post construction standards the committee has published, as well as other related documents and workshop activities.

The paper concludes with a look into the future, including strengths, weaknesses, opportunities, and threats. It is hoped that this paper offers unique insights into the history of post construction standards for pressure equipment and provides a case for continued involvement by interested volunteers to further develop and advance the mission of the committee.
Hydrogen Damage in Transfer Line Exchanger Tubes
Authors: Adams Amy , Huff Mary Catherine , Penso Jorge
Published: October 2021

This paper presents the analysis of a Transfer Line Exchanger (TLE) tube, which ruptured from hydrogen damage on the steam side. Hydrogen damage occurs where corrosion reactions result in the production of atomic hydrogen. Atomic hydrogen combines at grain boundaries or inclusions in the steel to produce molecular hydrogen. Hydrogen may also react with iron carbides (Fe3C) in the metal to produce methane (CH4). As a result, intergranular microfissures will form, linking to form larger microcracks and leading to eventual through-wall failure. Decarburization might also occur near the tube surface.

TLEs are heat exchangers designed to operate at extreme temperatures. In the exchanger design included in this study, pyrolysis furnace effluent gases enter the inner tubes at over 1500°F (815°C). The heat is then removed by water, which is supplied to concentric outer tubes, to generate steam. It is common for water-side damage in TLEs to occur at the tubesheet, where solids from boiler water are known to deposit and inhibit heat transfer. The nature of the rupture under discussion in this paper differs, because the location of the rupture was not near the tubesheet. Metallurgical analysis confirmed indications that the tube failure is attributed to hydrogen damage.
Effect of Internal Hydrogen on Fatigue Crack Initiation Sites in 316L Austenitic Stainless Steel
Authors: Kagay B. , Ronevich J. , San Marchi C.
Published: October 2021

Internal hydrogen can influence the fatigue life, crack growth rate, and crack morphology of austenitic stainless steel, but little is known about the effect of internal hydrogen on fatigue crack initiation sites. To determine the effect of internal hydrogen on the microstructural fatigue crack initiation sites, the location of small fatigue cracks was evaluated with respect to the microstructural features in notched middle tension M(T) 316L specimens both with and without pre-charged hydrogen. The notches of the M(T) specimens were electropolished prior to fatigue testing to facilitate post-test analysis. Fatigue tests were performed with the same constant load amplitude and an R-ratio of 0.1 for specimens with and without internal hydrogen. The fatigue tests were interrupted after a minimal amount of cracking was detected using the direct current potential difference (DCPD) technique. The microstructural locations of the small fatigue cracks were then evaluated with scanning electron microscopy imaging and electron backscatter diffraction (EBSD). Several small transgranular fatigue cracks initiated in the notches of specimens both with and without internal hydrogen. These transgranular cracks always intersected grain boundaries, twin boundaries, and/or triple points indicating that these microstructural features are the critical locations for crack initiation. The transgranular cracks did not propagate along the prominent slip traces. There was no discernible effect of hydrogen on the microstructural sites of fatigue crack initiation in 316L.
Thermal Analysis of a 9977 Shipping Package During a Fire-Drop-Smoldering Accident
Authors: Tamburello David , Kesterson Matthew , Escobar Andrew
Published: October 2021

The US Department of Energy (DOE) uses the 9977 shipping package to store and transport plutonium bearing materials. The shipping package utilizes a single 6-inch diameter containment vessel with the radioactive material within SAVY-4000 containers, 3013 food-pack containers, or other sealed storage containers separated by spacers. The 6-inch containment vessel is surrounded by load distribution fixtures and a foam insulation overpack to protect against fire and impact events. A facility fire-drop-smoldering accident, which is longer and hotter than the comparable regulatory transportation evaluation, is analyzed to ensure radioactive material containment is maintained. A sensitivity analysis of shipping package configuration and foam insulation reduction is considered with foam eliminated either along the inside wall of the drum body (Inner Foam) or eliminated from the outer walls of the inner chamber where the 6-inch containment vessel is located (Outer Foam). These two different foam reduction configurations were considered to conservatively simulate the potential aging effects on facility safety qualification during storage. In addition, the thermal properties of the foam insulation were varied to explore their potential aging effects. A minimum foam thickness needed to maintain containment during the hypothetical facility fire-drop-smoldering analysis is determined for both the Inner and Outer Foam configurations as well as for both the SAVY-4000 and 3013 food-pack container configurations.
Stress Relaxation Cracking of Thick-Wall Stainless Steel Piping in Various Refining Units
Authors: Penso Jorge , Shargay Cathleen
Published: October 2021

Hydrogen Manufacturing Units which have a Pre-reformer often use large diameter, thick-wall austenitic stainless steel (SS) piping operating at 540–650°C (1000–1200°F). In numerous units, circumferential welds in this piping have experienced failures due to stress relaxation cracking (SRC). Similarly, SRC has been reported in SS piping operating in this temperature range in hydroprocessing, olefin and coking units and in steam superheater coils in various units. This paper describes the in-service SRC mechanism and reports on some cracking case histories. It will also define how the risk varies depending on the process conditions, pipe size and thickness, fabrication steps and more. Additionally, this paper briefly lists the pros and cons of different material choices for this piping based on operating conditions, and ranks the materials for SRC resistance. Various other damage mechanisms also need to be considered and affect the optimum materials choice. The paper recommends steps for minimizing the risk of SRC of SS piping when SS is determined to be the preferred material choice. One of the key steps for providing resistance to in-service SRC is postweld heat treatment of the welds, but this has led to cases of reheat cracking during the fabrication stage. Guidelines for predicting and minimizing this risk are also reported.
Rotational Modular Metastructures for Cobot Impact Energy Absorption
Authors: Agarwal Vipin , Kidambi Narayanan , Wang K. W.
Published: October 2021

Collaborative robots (Cobots) are designed to allow humans to interact and work with them in close proximity. Although they are power- and force-limited compared to traditional industrial robots, residual injury risks in the event of a collision will cause Cobots to be operated at a reduced speed when humans are nearby. This compromises the ability to achieve manufacturing cycle time targets. Outlining safe zones around Cobots may allow quicker operations, but this approach poses challenges to manufacturing efficiency and leads to an increased robot footprint over a true collaborative unit. Incorporating energy-absorbing and force-limiting hardware into the Cobot structure may offer a way to ensure human safety without reducing manufacturing productivity and efficiency. Building upon such a concept, this research proposes a rotational multistable metastructure that can be incorporated in a Cobot’s joint. The metastructure consists of pre-buckled bistable beams constrained within a pair of concentric rings. These bistable elements snap through and absorb energy in consequence of applied rotational loads. In this study, modeling and analyses are performed using Euler’s elastica theory and results are used to guide the design of the metastructure, offering insight into properties such as rotation range, asymmetric bistability, and strain energy absorption. Using the geometric parameters obtained from the elastica study, numerical studies are conducted, and a modular constituent is fabricated and evaluated experimentally. While motivated by Cobot applications, it is expected that this work will serve as an important basis for a variety of engineering applications requiring energy absorption and force limitation for rotational loads.
An Experimental and Numerical Study of a Solid-State Ornithopter Wing Performance
Authors: Katibeh Mohammad , Bilgen Onur
Published: October 2021

Various concepts have been introduced in the literature to recreate avian wings’ flapping motion since natural flight has advantages for certain flight regimes, such as more maneuverability, efficiency, and agility, over fixed-wing aircraft. Similarly, the so-called solid-state ornithopter is designed to achieve a flapping wing motion; however, also achieves to use the minimum number of components. It utilizes an active layer of piezoelectric actuators over a composite substrate, and the flapping motion is generated through the induced strain from the piezoelectric actuators. Previously, a simplified rectangular plate-like design was studied for the variations of important geometric parameters. In this paper, more complicated and realistic geometries are investigated. The flapping performance is studied using a structural finite element model represented by parameters related to the wing’s motion such as tip displacement, bending curvature, and lateral slope. Furthermore, a set of experiments are conducted to verify the simulation results. During the experiments, the wing’s three-dimensional motion is recorded via a camera based motion-capture system. After that, the acquired data are processed using mathematical models to obtain the displacements, and parameters related to curvature, twist, and slope.
Intestinal Bacteriophage Therapy: Looking for Optimal Efficacy
Authors: Javaudin François , Latour Chloé , Debarbieux Laurent , Lamy-Besnier Quentin
Published: October 2021

Several human intestinal microbiota studies suggest that bacteriophages, viruses infecting bacteria, play a role in gut homeostasis. Currently, bacteriophages are considered a tool to precisely engineer the intestinal microbiota, but they have also attracted considerable attention as a possible solution to fight against bacterial pathogens resistant to antibiotics.
Susceptibilities of Human ACE2 Genetic Variants in Coronavirus Infection
Authors: Ren Wenlin , Zhu Yunkai , Lan Jun , Chen Hedi , Wang Yuyan , Shi Hongyang , Feng Fei , Chen Da-Yuan , Close Brianna , Zhao Xiaomin , Wu Jianping , Tian Boxue , Yuan Zhenghong , Zhou Dongming , Saeed Mohsan , Wang Xinquan , Zhang Rong , Ding Qiang
Published: October 2021

There is considerable variation in disease severity among patients infected with SARS-CoV-2, the virus that causes COVID-19. Human genetic variation can affect disease outcome, and the coronaviruses SARS-CoV, SARS-CoV-2, and HCoV-NL63 utilize human ACE2 as the receptor to enter cells.
The Glycan Hole Area of HIV-1 Envelope Trimers Contributes Prominently to the Induction of Autologous Neutralization
Authors: Schorcht Anna , Cottrell Christopher A. , Pugach Pavel , Ringe Rajesh P. , Han Alvin X. , Allen Joel D. , van den Kerkhof Tom L. G. M. , Seabright Gemma E. , Schermer Edith E. , Ketas Thomas J. , Burger Judith A. , van Schooten Jelle , LaBranche Celia C. , Ozorowski Gabriel , de Val Natalia , Bader Daniel L. V. , Schuitemaker Hanneke , Russell Colin A. , Montefiori David C. , van Gils Marit J. , Crispin Max , Klasse P. J. , Ward Andrew B. , Moore John P. , Sanders Rogier W.
Published: October 2021

Forty years after the first description of HIV-1, the search for a protective vaccine is still ongoing. The sole target for antibodies that can neutralize the virus are the trimeric envelope glycoproteins (Envs) located on the viral surface.
Adenovirus Remodeling of the Host Proteome and Host Factors Associated with Viral Genomes
Authors: Dybas Joseph M. , Lum Krystal K. , Kulej Katarzyna , Reyes Emigdio D. , Lauman Richard , Charman Matthew , Purman Caitlin E. , Steinbock Robert T. , Grams Nicholas , Price Alexander M. , Mendoza Lydia , Garcia Benjamin A. , Weitzman Matthew D.
Published: October 2021

Viral infections induce myriad changes to the host cell proteome. As viruses harness cellular processes and counteract host defenses, they impact abundance, posttranslational modifications, interactions, or localization of cellular proteins.
Engaging local health research communities to enhance long-term capacity building in Brazil
Authors: Madia Lourenço Luiza Helena , Baker Bonny Louise , Dias Junior Antonio Gregorio , Jamieson Nina E , Pacheco de Almeida Roque , Queiroz Gurgel Ricardo , Campello Bresani Salvi Cristiane , de Souza Clécio Gabriel , Longo Egmar , Gomes Bruno , Rocha David Mariana , Galvão Pavan Márcio , Pereira de Castro Daniele , Lacerda Nogueira Mauricio , Lang Trudie
Published: October 2021

The ‘2019 Research Capacity Network (REDe) workshop series’ was an initiative led by Brazil-based REDe coordinators and The Global Health Network (TGHN) in partnership with Brazilian researchers interested in arboviruses. This workshop initiative has provided crucial training to the local research community offering transferable skills to effectively respond to health emergencies, with an impact beyond arboviral diseases, as evidenced by further activities undertaken during the COVID-19 pandemic. The success of this approach resulted from several factors, especially the workshops’ local leadership and the combination of in-person training with online sharing of the resources generated in the local language. Analytics data from REDe online platform evidenced the wider reach of the shared resources to a larger audience than the workshop attendees. Importantly, the impact of this approach extends beyond the workshop series per se, with workshop participants afforded access to wider training, career development and collaborative opportunities through REDe and TGHN platforms. In addition, this initiative design resulted in the development of new collaborations between the workshop leaders and other local researchers, who have been jointly writing research projects and applying for grants. As a result, REDe has become a highly dynamic community of practice for health researchers in the region, strengthening the research culture and improving connectivity. Here, we describe the design and implementation of this initiative and demonstrate the value of integrating local expertise, and a practical workshop series format with digital dissemination of research resources and training materials to generate a vibrant and robust community of practice.
Evaluating the utility of digital phenotyping to predict health outcomes in schizophrenia: protocol for the HOPE-S observational study
Authors: Abdul Rashid Nur Amirah , Martanto Wijaya , Yang Zixu , Wang Xuancong , Heaukulani Creighton , Vouk Nikola , Buddhika Thisum , Wei Yuan , Verma Swapna , Tang Charmaine , Morris Robert J T , Lee Jimmy
Published: October 2021

Introduction

The course of schizophrenia illness is characterised by recurrent relapses which are associated with adverse clinical outcomes such as treatment-resistance, functional and cognitive decline. Early identification is essential and relapse prevention remains a primary treatment goal for long-term management of schizophrenia. With the ubiquity of devices such as smartphones, objective digital biomarkers can be harnessed and may offer alternative means for symptom monitoring and relapse prediction. The acceptability of digital sensors (smartphone and wrist-wearable device) and the association between the captured digital data with clinical and health outcomes in individuals with schizophrenia will be examined.

Methods and analysis

In this study, we aim to recruit 100 individuals with schizophrenia spectrum disorders who are recently discharged from the Institute of Mental Health (IMH), Singapore. Participants are followed up for 6 months, where digital, clinical, cognitive and functioning data are collected while health utilisation data are obtained at the 6 month and 1 year timepoint from study enrolment. Associations between digital, clinical and health outcomes data will be examined. A data-driven machine learning approach will be used to develop prediction algorithms to detect clinically significant outcomes. Study findings will inform the design, data collection procedures and protocol of future interventional randomised controlled trial, testing the effectiveness of digital phenotyping in clinical management of individuals with schizophrenia spectrum disorders.

Ethics and dissemination

Ethics approval has been granted by the National Healthcare Group (NHG) Domain Specific Review Board (DSRB Reference no.: 2019/00720). The results will be published in peer-reviewed journals and presented at conferences.

Trial registration number

NCT04230590.
Association between mental health trajectories and somatic symptoms
following a second lockdown in Israel: a longitudinal study
Authors: Ben-Ezra Menachem , Hamama-Raz Yaira , Goodwin Robin , Leshem Elazar , Levin Yafit
Published: October 2021

Objectives

To identify mental health prospective trajectories before and after
a second lockdown during the COVID-19 pandemic and their associations
with somatic symptoms.

Design

Prospective Study.

Setting

Population-based study drawn from a probability-based internet panel
of over 100 000 Israelis.

Participants

Adults aged 18 years or more, representative of the adult Israeli
population. The participants were measured at two time points (time 1
(T1) pre-second lockdown N=1029; response rate=76.17%; time 2 (T2)
post-second lockdown N=764; response rate=74.24%).

Main outcome measures

Trajectories of anxiety and adjustment disorder based on clinical
cut-off score for probable diagnoses across T1-T2, somatic symptoms at
T2. The four trajectories: stable-low, (no probable diagnosis),
stable-high (stable probable diagnosis), exacerbation (no probable
diagnosis at T1, probable diagnosis at T2), recovery (probable diagnosis
at T1, no probable diagnosis at T2).

Results

Three anxiety trajectories predicted probable somatic symptoms
(stable-high OR=6.451; exacerbation OR=5.379; recovery OR=2.025)
compared with the stable-low trajectory. The three adjustment disorder
trajectories also predicted somatic symptoms (stable-high OR=4.726;
exacerbation OR=6.419; recovery OR=4.666) compared with the stable-low
trajectory.

Conclusions

Our data show elevated somatic symptoms among those whose mental
health trajectories were poor, exacerbated and those who recovered
following the second lockdown. The presentation of somatic symptoms may
mask psychological vulnerabilities, even among those who appear to have
recovered from the stressor. This indicates that lockdown may be a
double-edged sword and should be carefully administered given these
populations vulnerabilities.
Community health workers’ job satisfaction in Ebola-stricken areas of Sierra Leone and its implication for COVID-19 containment: a cross-sectional mixed-methods study
Authors: Koroma Osman , Chen Yanhua , Wang Peicheng , Chen Geer , Lin Qian , Cheung Ming Yen , Zhu Jiming
Published: October 2021

Objectives

Community health workers (CHWs) played important roles in supplementing scarce healthcare workforce in Sierra Leone during the Ebola outbreak, causing the government to launch the National Community Health Worker Policy 2016–2020. This study evaluated this ambitious policy and examined CHWs’ sustainability through their job satisfaction and the underlying factors to inform new policy recommendations, especially the implication for COVID-19 containment.

Design

A mixed-methods approach applying structured questionnaires and semistructured interviews.

Setting and participants

188 CHWs in Bombali District (key Ebola-stricken areas) of Sierra Leone, 184 of them participated in follow-up interviews.

Primary and secondary outcome measures

Quantitative and qualitative elements were triangulated to improve robustness of investigation: job satisfaction was measured by the Minnesota Satisfaction Questionnaire (MSQ), and factors associated with job satisfaction were identified through thematic analysis and multivariable logistic regression.

Results

The MSQ score of CHWs in Sierra Leone was 65.09, extremely low even among low-income and middle-income countries. Five themes (grouped from 16 subthemes) emerged through the semistructured interviews and were tested quantitatively. Payment was CHWs’ top concern. Low stipend and payment tardiness were significantly associated with dissatisfaction. Those with Ebola experience were 5.20 times (95% CI 1.51 to 17.95, p=0.009) more likely to be dissatisfied. This study also found that working conditions, medical material supplies and career development were far from what the CHW policy promised. CHWs’ commitment was the only ‘positive’ theme, and their intrinsic job satisfaction (mean=3.61) was much higher than the extrinsic job satisfaction (mean=2.72).

Conclusions

Some critical components of the 2016 National Community Health Worker Policy, aiming to promote CHWs and strengthen primary healthcare, have severe shortfalls in practice. The Sierra Leone government should address the underlying factors that have impaired CHWs’ job satisfaction to ensure sustainability of its CHW network, especially during the combat against COVID-19.
Glucose-lowering drugs and outcome from COVID-19 among patients with type 2 diabetes mellitus: a population-wide analysis in Hong Kong
Authors: Luk Andrea On Yan , Yip Terry C F , Zhang Xinge , Kong Alice Pik Shan , Wong Vincent Wai-Sun , Ma Ronald Ching Wan , Wong Grace Lai-Hung
Published: October 2021

Objectives

To investigate the association between baseline use of glucose-lowering drugs and serious clinical outcome among patients with type 2 diabetes.

Design

Territory-wide retrospective cohort of confirmed cases of COVID-19 between January 2020 and February 2021.

Setting

All public health facilities in Hong Kong.

Participants

1220 patients with diabetes who were admitted for confirmed COVID-19.

Primary and secondary outcome measures

Composite clinical endpoint of intensive care unit admission, requirement of invasive mechanical ventilation and/or in-hospital death.

Results

In this cohort (median age 65.3 years, 54.3% men), 737 (60.4%) patients were treated with metformin, 385 (31.6%) with sulphonylureas, 199 (16.3%) with dipeptidyl peptidase-4 (DPP-4) inhibitors and 273 (22.4%) with insulin prior to admission. In multivariate Cox regression, use of metformin and DPP-4 inhibitors was associated with reduced incidence of the composite endpoint relative to non-use, with respective HRs of 0.51 (95% CI 0.34 to 0.77, p=0.001) and 0.46 (95% CI 0.29 to 0.71, p<0.001), adjusted for age, sex, diabetes duration, glycated haemoglobin (HbA1c), smoking, comorbidities and drugs. Use of sulphonylureas (HR 1.55, 95% CI 1.07 to 2.24, p=0.022) and insulin (HR 6.34, 95% CI 3.72 to 10.78, p<0.001) were both associated with increased hazards of the composite endpoint.

Conclusions

Users of metformin and DPP-4 inhibitors had fewer adverse outcomes from COVID-19 compared with non-users, whereas insulin and sulphonylurea might predict a worse prognosis.
Towards an open and effective dialogue on complementary medicine in oncology: protocol of patient participatory study ‘COMMON’
Authors: Mentink Marit , Noordman Janneke , Busch Martine , van Vliet Liesbeth , Timmer-Bonte Johanna (Anja) , van Dulmen Sandra
Published: October 2021

Introduction

Approximately half of patients with cancer use some form of complementary medicine alongside conventional cancer treatment. The topic of complementary medicine often remains undiscussed in consultations between patients with cancer and their healthcare providers. This results in increased risks for adverse or interaction effects and decreased access to the benefits of evidence-based complementary medicine for patients with cancer. This paper describes the design of patient participatory study titled ‘COMMON’ that aims to explore and enhance open and effective communication about complementary medicine in oncology. The study is carried out in collaboration with 12 (former) patients with breast cancer as coresearchers.

Methods and analysis

The study complies with the six steps of the intervention mapping framework. Three non-academic hospitals recruit participants (patients with cancer, oncology healthcare providers and managers) for interviews about the organisation, experiences and needs regarding complementary medicine. To assess communication about complementary medicine, recorded oncology consultations are analysed. For an overview of evidence-based complementary medicine available to patients with cancer, a review of reviews is conducted on the evidence on cancer patient-reported outcomes of complementary medicine frequently used by patients with cancer, supplemented with an online search and survey among organisations and persons providing complementary medicine to patients with cancer. Together, these steps generate input for the development of a toolbox that supports an open and effective discussion on complementary medicine in oncology. In a pilot study, acceptability and usability of the toolbox are assessed among patients with cancer and oncology healthcare providers. Dissemination of the toolbox is covered by the commitment of stakeholder parties.

Ethics and dissemination

The Medical Ethics Committee Arnhem-Nijmegen declared the study was exempted from formal approval under the Dutch Medical Research Involving Human Subjects Act. The results will be disseminated through open-access, peer-reviewed publications, stakeholder-reporting and presentations at relevant conferences.
Effects of in situ wetting–drying cycles on the mechanical behaviour of an intact loess
Authors: Mu Q.Y. , Dong H. , Liao H.J. , Zhou C. , Li S.B. , Zhang J.W.
Published: October 2021

In situ wetting–drying cycles significantly and repeatedly influence the soil water content in the active zone but not in the steady zone. To investigate effects of in situ wetting–drying cycles on the mechanical behaviour of intact loess, a series of pressure plate tests was carried out with an intact loess sampled from the active and steady zones. Results show that the specimens from the steady zone have higher yield stresses at given suctions and a larger inclination of normalized loading collapse (LC) curve than the specimens from the active zone. As evidenced by the scanning electron microscopy results, the clay particles accumulating around the contacts between silt particles are widely observed in the former specimens but not in the latter specimens. The distribution of clay particles in the former specimens results in a stabilized skeleton with mechanical properties sensitive to suction variations. On the other hand, the maximum collapse potential of the specimen from the steady zone is 37% larger than that of the specimen from the active zone, mainly because of the larger inclination of normalized LC curve owned by the former specimen.
The effect of loading frequency on the long-term cyclic behavior of dense calcareous sand
Authors: He Shao-Heng , Goudarzy Meisam , Ding Zhi , Sun Yifei , Xia Tang-Dai
Published: October 2021

Transportation infrastructure foundations filled with calcareous sand are exposed to long-term cyclic loading under various frequencies. This study presents experimental results about the drained cyclic triaxial tests conducted on dense calcareous sand under different mean effective stresses ([Formula: see text]), cyclic stress ratios (ζ), and loading frequencies (f) to examine the effect of f on the long-term cyclic behavior. Results show that the increase in f causes the significant increase in the accumulated axial strain ([Formula: see text]). As ζ increases, [Formula: see text] becomes more sensitive to f, while the increase of p0 could limit the aggravating effect of f on [Formula: see text]. At a higher ζ, increasing f can even lead to a failure and larger dilated volumetric strain of dense calcareous sand specimens. The increase in f has a considerable impairing effect on the shakedown behavior, which can cause the stable shakedown behavior to transform into transitional or unstable shakedown behaviors. More accurate shakedown discriminant boundaries suitable for calcareous sand under different f were therefore proposed.
Frozen out: unanswered questions about winter biology
Authors: Sutton Alex O. , Studd Emily K. , Fernandes Timothy , Bates Amanda E. , Bramburger Andrew J. , Cooke Steven J. , Hayden Brian , Henry Hugh A.L. , Humphries Murray M. , Martin Rosemary , McMeans Bailey , Moise Eric , O’Sullivan Antóin M. , Sharma Sapna , Templer Pamela H.
Published: October 2021

Winter conditions impose dramatic constraints on temperate, boreal, and polar ecosystems, and shape the abiotic and biotic interactions underpinning these systems. At high latitudes, winter can last longer than the growing season and may have a disproportionately large impact on organisms and ecosystems. Even so, our understanding of the ecological implications of winter is often lacking. Indeed, even what exactly defines winter is currently unclear, and boundaries that delineate this season are blurred across marine, freshwater, and terrestrial realms and fields of biology. Here, we discuss the complexity of defining winter, and highlight the importance of maintaining the capacity to test hypotheses across seasons, realms, and domains of life. We then outline questions drawn from diverse fields of research that address current gaps in our understanding of winter ecology and how winter influences multiple levels of biological organization, from individuals to ecosystems. Finally, we highlight the potential consequences of changes to both the length and severity of winter due to climate change, and discuss the role winter may play in mediating ecosystem function in the future.
Static magnetic susceptibility in finite-density $$SU\left( 2\right) $$ lattice gauge theory
Authors: Buividovich P. V. , Smith D. , von Smekal L.
Published: October 2021

We study static magnetic susceptibility $$\chi (T, \mu )$$

χ
(
T
,
μ
)

in SU(2) lattice gauge theory with $$N_f = 2$$

N
f

=
2

light flavours of dynamical fermions at finite chemical potential $$\mu $$
μ
. Using linear response theory we find that SU(2) gauge theory exhibits paramagnetic behavior in both the high-temperature deconfined regime and the low-temperature confining regime. Paramagnetic response becomes stronger at higher temperatures and larger values of the chemical potential. For our range of temperatures $$0.727 \le T/T_c \le 2.67$$

0.727
≤
T
/

T
c

≤
2.67

, the first coefficient of the expansion of $$\chi \left( T, \mu \right) $$

χ

T
,
μ

in even powers of $$\mu /T$$

μ
/
T

around $$\mu =0$$

μ
=
0

is close to that of free quarks and lies in the range $$(2, \ldots , 5) \cdot 10^{-3}$$

(
2
,
…
,
5
)

·

10

-
3

. The strongest paramagnetic response is found in the diquark condensation phase at $$\mu >m\pi /2$$

μ
>
m
π
/
2

.
Casimir wormholes in $$2+1$$ dimensions with applications to the graphene
Authors: Alencar G. , Bezerra V. B. , Muniz C. R.
Published: October 2021

In this paper we show that wormholes in (2+1) dimensions (3-D) cannot be sourced solely by both Casimir energy density and tension, differently from what happens in a 4-D scenario, in which case it has been shown recently, by the direct computation of the exact shape and redshift functions of a wormhole solution, that this is possible. We show that in a 3-D spacetime the same is not true since the arising of at least an event horizon is inevitable. We do the analysis for massive and massless fermions, as well as for scalar fields, considering quasi-periodic boundary conditions and find that a possibility to circumvent such a restriction is to introduce, besides the 3-D Casimir energy density and tension, a cosmological constant, embedding the surface in a 4-D manifold and applying a perpendicular weak magnetic field. This causes an additional tension on it, which contributes to the formation of the wormhole. Finally, we discuss the possibility of producing the condensed matter analogous of this wormhole in a graphene sheet and analyze the electronic transport through it.
Casimir-Lifshitz pressure on cavity walls
Authors: Romaniega C.
Published: October 2021

We extend our previous work on the electromagnetic Casimir-Lifshitz interaction between two bodies when one is contained within the other. We focus on the fluctuation-induced pressure acting on the cavity wall, which is assumed to be spherical. This pressure can be positive or negative depending on the response functions describing the bodies and the medium filling the cavity. However, we find that under general hypotheses, the sign is independent of the geometry of the configuration. This result is based on the representation of the Casimir-Lifshitz energy in terms of transition operators. In particular, we study the components of these operators related to inside scattering amplitudes, adapting the invariant imbedding procedure to this unfamiliar scattering setup. We find that our main result is in agreement with the Dzyaloshinskii–Lifshitz–Pitaevskii result, which is obtained as a limiting case.
Fundamental Fluid Dynamics Challenges in Inkjet Printing
Authors: Lohse Detlef
Published: October 2021

Inkjet printing is the most widespread technological application of microfluidics. It is characterized by its high drop productivity, small volumes, and extreme reproducibility. This review gives a synopsis of the fluid dynamics of inkjet printing and discusses the main challenges for present and future research. These lie both on the printhead side—namely, the detailed flow inside the printhead, entrained bubbles, the meniscus dynamics, wetting phenomena at the nozzle plate, and jet formation—and on the receiving substrate side—namely, droplet impact, merging, wetting of the substrate, droplet evaporation, and drying. In most cases the droplets are multicomponent, displaying rich physicochemical hydrodynamic phenomena. The challenges on the printhead side and on the receiving substrate side are interwoven, as optimizing the process and the materials with respect to either side alone is not enough: As the same ink (or other jetted liquid) is used and as droplet frequency and size matter on both sides, the process must be optimized as a whole.
Vortex Reconnection and Turbulence Cascade
Authors: Yao Jie , Hussain Fazle
Published: October 2021

As a fundamental topology-transforming event, reconnection plays a significant role in the dynamics of plasmas, polymers, DNA, and fluids—both (classical) viscous and quantum. Since the 1994 review by Kida & Takaoka, substantial advances have been made on this topic. We review recent studies of vortex reconnection in (classical) viscous flows, including the physical mechanism, its relationship to turbulence cascade, the formation of a finite-time singularity, helicity dynamics, and aeroacoustic noise generation.
mRNA Vaccines in the COVID-19 Pandemic and Beyond
Authors: Hogan Michael J. , Pardi Norbert
Published: October 2021

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of coronavirus disease 2019 (COVID-19), emerged in China in December 2019 and quickly spread around the globe, killing more than 4 million people and causing a severe economic crisis. This extraordinary situation prompted entities in government, industry, and academia to work together at unprecedented speed to develop safe and effective vaccines. Indeed, vaccines of multiple types have been generated in record time, and many have been evaluated in clinical trials. Of these, messenger RNA (mRNA) vaccines have emerged as lead candidates due to their speed of development and high degree of safety and efficacy. To date, two mRNA vaccines have received approval for human use, providing proof of the feasibility of this next-generation vaccine modality. This review gives a detailed overview about the types of mRNA vaccines developed for SARS-CoV-2, discusses and compares preclinical and clinical data, gives a mechanistic overview about immune responses generated by mRNA vaccination, and speculates on the challenges and promising future of this emergent vaccine platform.
Endothelial upregulation of mechanosensitive channel Piezo1 in pulmonary hypertension
Authors: Wang Ziyi , Chen Jiyuan , Babicheva Aleksandra , Jain Pritesh P. , Rodriguez Marisela , Ayon Ramon J. , Ravellette Keeley S. , Wu Linda , Balistrieri Francesca , Tang Haiyang , Wu Xiaomin , Zhao Tengteng , Black Stephen M. , Desai Ankit A. , Garcia Joe G. N. , Sun Xin , Shyy John Y.-J. , Valdez-Jasso Daniela , Thistlethwaite Patricia A. , Makino Ayako , Wang Jian , Yuan Jason X.-J.
Published: October 2021

Piezo is a mechanosensitive cation channel responsible for stretch-mediated Ca2+ and Na+ influx in multiple types of cells. Little is known about the functional role of Piezo1 in the lung vasculature and its potential pathogenic role in pulmonary arterial hypertension (PAH). Pulmonary arterial endothelial cells (PAECs) are constantly under mechanic stretch and shear stress that are sufficient to activate Piezo channels. Here, we report that Piezo1 is significantly upregulated in PAECs from patients with idiopathic PAH and animals with experimental pulmonary hypertension (PH) compared with normal controls. Membrane stretch by decreasing extracellular osmotic pressure or by cyclic stretch (18% CS) increases Ca2+-dependent phosphorylation (p) of AKT and ERK, and subsequently upregulates expression of Notch ligands, Jagged1/2 (Jag-1 and Jag-2), and Delta like-4 (DLL4) in PAECs. siRNA-mediated downregulation of Piezo1 significantly inhibited the stretch-mediated pAKT increase and Jag-1 upregulation, whereas downregulation of AKT by siRNA markedly attenuated the stretch-mediated Jag-1 upregulation in human PAECs. Furthermore, the mRNA and protein expression level of Piezo1 in the isolated pulmonary artery, which mainly contains pulmonary arterial smooth muscle cells (PASMCs), from animals with severe PH was also significantly higher than that from control animals. Intraperitoneal injection of a Piezo1 channel blocker, GsMTx4, ameliorated experimental PH in mice. Taken together, our study suggests that membrane stretch-mediated Ca2+ influx through Piezo1 is an important trigger for pAKT-mediated upregulation of Jag-1 in PAECs. Upregulation of the mechanosensitive channel Piezo1 and the resultant increase in the Notch ligands (Jag-1/2 and DLL4) in PAECs may play a critical pathogenic role in the development of pulmonary vascular remodeling in PAH and PH.
Melatonin ameliorates aging-related impaired angiogenesis in gastric endothelial cells via local actions on mitochondria and VEGF-survivin signaling
Authors: Ahluwalia Amrita , Patel Khushin , Hoa Neil , Brzozowska Iwona , Jones Michael K. , Tarnawski Andrzej S.
Published: October 2021

This study showed reduced expression of melatonin receptors MT1 and MT2, angiogenesis, and mitochondrial function in gastric endothelial cells (GECs) isolated from aging rats. Treatment of aging GECs with melatonin increases expression of VEGF receptor and survivin and ameliorates aging-related impaired angiogenesis and mitochondrial function. These studies provide new insight into the mechanisms of the aging-related impairment of angiogenesis and delayed tissue injury healing and provide a rationale for melatonin treatment to reverse these abnormalities.