bluuebunny/crossref_metadata_2025 huggingface dataset:
High temperature phase stability of the compositionally complex alloy AlMo0.5NbTa0.5TiZr
Authors: Kloenne Zachary T. , Kadirvel Kamalnath , Couzinie Jean-Philippe , Viswanathan Gopal B. , Wang Yunzhi , Fraser Hamish L.
Published: October 2021

Recently, a class of refractory high-entropy alloys has been developed with a refined microstructure consisting of an ordered B2 matrix with cuboidal BCC precipitates resembling an “inverted superalloy-like” microstructure. In this paper, we have studied the evolution of the duplex microstructure of AlMo0.5NbTa0.5TiZr during aging at elevated temperatures, particularly with regard to the nature of the B2 and BCC phases. Samples were aged at 1000 °C for 6 h, followed by a water quench. It was found that while the relative volume fractions of the B2 and BCC phases remained nearly constant after ageing, compositional changes of both the B2 and BCC phases were determined. In the aged condition, there is evidence from high-resolution STEM HAADF imaging that suggests that the B2 phase in the aged condition may undergo a spinodal reaction, with the sub-lattice occupancies differing within the ordered precipitates. A change in size and shape of the BCC precipitates was also noted, and this was accompanied by a difference in the nature of the B2/BCC interfaces. Thus, a step-like B2/BCC interface is evidenced in the aged condition, in contrast with the planar {100} interfaces in the “superalloy-like” microstructure, likely adopted to accommodate a change in coherency resulting from an increase in misfit between the two phases from compositional changes occurring during the coarsening of the BCC precipitates.
Comprehensive analysis of 14-3-3 family genes and their responses to cold and drought stress in cucumber
Authors: Xu Mingyuan , Hu Zhaoyang , Lai Wei , Liu Shiqiang , Wu Hao , Zhou Yong
Published: October 2021

The 14-3-3 proteins play essential roles in regulating various biological processes and abiotic stress responses in plants. However, there have been few studies of 14-3-3 family members in cucumber. Here, we identified a total of ten 14-3-3 genes (named as CsGF14a–j) in the cucumber genome. These genes are unevenly distributed across six cucumber chromosomes, and six of them were found to be segmentally duplicated. A phylogenetic analysis of 14-3-3 proteins in cucumber and other plant species showed that they could be divided into two distinct groups (ε and non-ε). Members in the same group tend to have similar exon-intron structure and conserved motif patterns. Several hormone-, stress- and development-related cis-elements associated with transcriptional regulation were found in the promoters of CsGF14 genes. RNA-seq data showed that most CsGF14 genes have broad expression in different tissues, and some had preferential expression in specific tissues and variable expression at certain developmental stages during fruit development. Quantitative real-time PCR (qRT-PCR) results revealed that nearly all tested CsGF14 genes were significantly up-regulated under cold and drought stress at certain time points. These results provide important information about the functions of CsGF14 genes in cucumber.
Linking species traits and demography to explain complex temperature responses across levels of organization
Authors: Wieczynski Daniel J. , Singla Pranav , Doan Adrian , Singleton Alexandra , Han Ze-Yi , Votzke Samantha , Yammine Andrea , Gibert Jean P.
Published: October 2021

Significance

Microbes regulate nutrient flux and carbon storage within ecosystems, making them essential to the global carbon cycle and ecosystem responses to climate change. Understanding how climate change will alter microbial communities and how this will feed back to influence the pace of climate change requires linking processes across levels of organization, from individual organisms to whole ecosystems. We show that the physical characteristics (traits) of protist species influence how their populations will respond to changes in temperature. These species-level temperature responses also alter the composition, dynamics, and functioning of whole microbial communities. Using traits to understand how complex, multilevel microbial processes change with temperature can help us anticipate possible consequences of rapid global climate change.
Dynamic changes in tRNA modifications and abundance during T cell activation
Authors: Rak Roni , Polonsky Michal , Eizenberg-Magar Inbal , Mo Yufeng , Sakaguchi Yuriko , Mizrahi Orel , Nachshon Aharon , Reich-Zeliger Shlomit , Stern-Ginossar Noam , Dahan Orna , Suzuki Tsutomu , Friedman Nir , Pilpel Yitzhak
Published: October 2021

The tRNA pool determines the efficiency, throughput, and accuracy of translation. Previous studies have identified dynamic changes in the tRNA (transfer RNA) supply and mRNA (messenger RNA) demand during cancerous proliferation. Yet dynamic changes may also occur during physiologically normal proliferation, and these are less well characterized. We examined the tRNA and mRNA pools of T cells during their vigorous proliferation and differentiation upon triggering their antigen receptor. We observed a global signature of switch in demand for codons at the early proliferation phase of the response, accompanied by corresponding changes in tRNA expression levels. In the later phase, upon differentiation, the response of the tRNA pool relaxed back to the basal level, potentially restraining excessive proliferation. Sequencing of tRNAs allowed us to evaluate their diverse base-modifications. We found that two types of tRNA modifications, wybutosine and ms
2
t6A, are reduced dramatically during T cell activation. These modifications occur in the anticodon loops of two tRNAs that decode “slippery codons,” which are prone to ribosomal frameshifting. Attenuation of these frameshift-protective modifications is expected to increase the potential for proteome-wide frameshifting during T cell proliferation. Indeed, human cell lines deleted of a wybutosine writer showed increased ribosomal frameshifting, as detected with an HIV gag-pol frameshifting site reporter. These results may explain HIV’s specific tropism toward proliferating T cells since it requires ribosomal frameshift exactly on the corresponding codon for infection. The changes in tRNA expression and modifications uncover a layer of translation regulation during T cell proliferation and expose a potential tradeoff between cellular growth and translation fidelity.
Spontaneous helielectric nematic liquid crystals: Electric analog to helimagnets
Authors: Zhao Xiuhu , Zhou Junchen , Li Jinxing , Kougo Junichi , Wan Zhe , Huang Mingjun , Aya Satoshi
Published: October 2021

Significance

The recent discovery of the emerging ferroelectric nematics opens an avenue not only for exploring exotic polar matter states in condensed matter physics but also for providing opportunities toward brand new liquid crystal technologies. Here, we revealed the existence of a helielectric nematic state by introducing the chirality into the ferroelectric nematics. Combining multiple intercorrelated measurements, we confirmed a helicoidal-type polar vector field in the helielectric nematics. The emergent polar symmetry triggers distinctions in topology to the dielectric cholesterics. Via proper doping of chiral generators, the helielectric state can survive down to room temperature, retaining excellent nonlinear optical and dielectric properties. Hence, it offers a stable material platform for exploring unidentified polarity–chirality–coupled textures and developing functional electrooptical devices.
A topic modeling analysis of Korea’s T&I research trends in the 2010s
Authors: Lee Changsoo
Published: October 2021

The present study aims to demonstrate the relevance of topic modeling as a new research tool for analyzing research trends in the T&I field. Until now, most efforts to this end have relied on manual classification based on pre-established typologies. This method is time- and labor-consuming, prone to subjective biases, and limited in describing a vast amount of research output. As a key component of text mining, topic modeling offers an efficient way of summarizing topic structure and trends over time in a collection of documents while being able to describe the entire system without having to rely on sampling. As a case study, the present paper applies the technique to analyzing a collection of abstracts from four Korean Language T&I journals for the 2010s decade (from 2010 to 2019). The analysis proves the technique to be highly successful in uncovering hidden topical structure and trends in the abstract corpus. The results are discussed along with implications of the technique for the T&I field.
Figurative language in multilingual students’ L2 Swedish – a usage-based perspective
Authors: Prentice Julia
Published: October 2021

The aim of the current paper is to reinterpret some results of two previous studies on the mastery of figurative
expressions from the perspective of usage-based linguistics. The reanalysis aims to shed more light on the learning and use of
figurative language by multilingual students by exploring the complex interplay of linguistic creativity, expressivity, and
conventionality in figurative expressions. The reinterpretation shows that many of the examples that were previously categorized
as novel figurative expressions used in students’ writing, can be analyzed as instances of regular patterns, i.e.
constructions, with certain lexical idiosyncrasies. Modifications of conventionalized figurative expressions are discussed and
reinterpreted in terms of strength of entrenchment of links between form and meaning within certain constructions or links between
constructions and conventionalized pragmatic information in the multilinguals’ mental construction. Implications for the treatment
of Swedish figurative expressions in the second language class room are, in line with previous research, that focusing on
regularity might reduce unpredictability, often seen as the core difficulty in the learning of such expressions in an L2. The
paper also offers some directions for further investigation of the socio-cognitive processes involved in the learning of
figurative language in an additional language.
Linear instability of elliptic rhombus solutions to the planar four-body problem
Authors: Liu Bowen
Published: October 2021

In this paper, we study the linear stability of the elliptic rhombus solutions, which are the Keplerian homographic solution with the rhombus central configurations in the classical planar four-body problems. Using ω-Maslov index theory and trace formula, we prove the linear instability of elliptic rhombus solutions if the shape parameter u and the eccentricity of the elliptic orbit e satisfy

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where u
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≈
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. Motivated on numerical results of the linear stability to the elliptic Lagrangian solutions in Martínez et al (2006 J. Differ. Equ.
226 619–651), we further analytically prove the linear instability of elliptic rhombus solutions for

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Effect of shear thickening gel on structure and properties of flexible polyurethane foam
Authors: Liu Xiaoke , Yu Kejing , Sun Jie , Guo Wenwen , Qian Kun
Published: October 2021

Compression and low-velocity impact properties of shear thickening gel/polyurethane foam (STG/PUF), a soft protective material, have been reported. In order to have a deeper understanding of the relationship between the structure and properties of this material, we utilized Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and Proton nuclear magnetic resonance (1H-NMR) to study and prove that STG and polyurethane (PU) did not produce new chemical bonds during the blending process, which belongs to physical blending. Because the molecular chains of STG and PU are intertwined, the composites are endowed with higher thermal stability, safety protection performance, and shape memory performance. For instance, Young’s modulus (E) of the STG/PUF was automatically increased by 57% when stimulated by external forces at different rates and the Emax
over 200 kPa, demonstrating a pronounced shear thickening effect. Shape memory tests showed that the shape fixity ratio of STG/PUF gradually increases with the increase of STG content, and the shape recovery ratio remained at 100%. More importantly, the STG/PUF was flexible and comfortable, had excellent mechanical properties and a longer service life, and can be extended to various human protective equipment.
Preparation of a small-size superconducting joint for C-doped 30-filament MgB2 wires
Authors: Xi Dan , Wang Dayou , Xinwei Cai , Wang Qingyang , Huang Zigeng , Nie Ruijuan , Yan Guo , Wang Furen , Gan Zizhao
Published: October 2021

A preparation method of a small-size MgB2 superconducting joint with 2.0 mm diameter for C-doped 30-filament MgB2 wires is presented in this paper. Herein, an unreacted in situ C-doped monofilament wire was utilized as the connecting structure, since it contains a low quantity of dense precursor which needs less pressure during fabrication, avoiding distortion of the multifilament in the parent wires, as shown in SEM images. After heat treatment, the formed C-doped MgB2 bulk with small volume in the joint has the ability to release heat quickly, resulting in good stability. The morphology of the joint proved the MgB2–MgB2 interface between the monofilament and 30-filament wire had been successfully connected. The joint sintered at 600 °C for 2 h shows an apparent superconducting transition with T
c-on = 33.49 K and has negligible resistance below 30.56 K as depicted in the R–T curve. It also has approximately 40% Jc
value of the parent 30-filament wire, at 4.2 K in 3 T.
Quasi-exactly solvable decatic model description of nuclei near the X(5) critical point
Authors: Sobhani Hadi , Hassanabadi Hassan , Bonatsos Dennis , Pan Feng , Draayer Jerry P
Published: October 2021

The Bohr Hamiltonian with axially deformed shape confined in a quasi-exactly solvable decatic β-part potential is studied. It is shown that the decatic model can well reproduce the X(5) model results as far as the energy ratios in the ground and beta band and related B(E2) values are concerned. Fitting results to the low-lying energy ratios and relevant B(E2) values of even–even X(5) candidates 150Nd, 156Dy, 164Yb, 168Hf, 174Yb, 176,178,180Os, and 188,190Os show that the decatic model provides the best fitting results for the energy ratios, while the X(5) model is the best at reproducing the B(E2) values of these nuclei, in which the beta-bandhead energy is lower than that of the gamma band. While for even–even nuclei, such as 154,156,158Gd, with bandhead energies of the beta and gamma bands more or less equal within the X(5) critical point to the axially deformed region, our numerical analysis indicates that the decatic model is better than the X(5) model in describing both the low-lying level energies and related B(E2) values.
Investigation of plasma wall interactions between tungsten plasma facing components and helium plasmas in the WEST tokamak
Authors: Tsitrone E. , Pegourie B. , Gunn J.P. , Bernard E. , Bruno V. , Corre Y. , Delpech L. , Diez M. , Douai D. , Ekedahl A. , Fedorczak N. , Gallo A. , Loarer T. , Vartanian S. , Gaspar J. , Le Bohec M. , Rigollet F. , Bisson R. , Brezinsek S. , Dittmar T. , De Temmerman G. , Hakola A. , Wauters T. , Balden M. , Mayer M. , WEST Team
Published: October 2021

ITER will operate with a tungsten divertor, a material featuring surface morphology changes when exposed to helium plasmas, in particular the formation of the so called tungsten fuzz under specific conditions. Investigating interactions between tungsten plasma facing components and helium plasmas in a tokamak environment is therefore a key point to consolidate predictions for the ITER divertor performance and lifetime. To this end, a dedicated helium campaign was performed in the full tungsten WEST tokamak, cumulating ∼2000 s of repetitive L mode discharges. It is shown that conditions for tungsten fuzz formation, as derived from linear devices experiments (incident helium energy E
inc > 20 eV, helium fluence >1024 He/m2, surface temperature T
surf > 700 °C), were met in the outer strike point (OSP) area of the inertially cooled tungsten divertor elements of WEST. Preliminary inspection of the components after the campaign did not show visible signs of surface modification, but points to significant net erosion in the OSP area. An extensive post mortem analysis is now ongoing to confirm these first indications. These results underline that the complex balance between erosion/redeposition (in particular linked to impurities) and tungsten fuzz formation needs to be taken into account in tokamak conditions.
Enabling peristalsis of human colon tumor organoids on microfluidic chips
Authors: Fang Guocheng , Lu Hongxu , Al-Nakashli Russul , Chapman Robert , Zhang Yingqi , Ju Lining Arnold , Lin Gungun , Stenzel Martina H , Jin Dayong
Published: October 2021

Peristalsis in the digestive tract is crucial to maintain physiological functions. It remains challenging to mimic the peristaltic microenvironment in gastrointestinal organoid culture. Here, we present a method to model the peristalsis for human colon tumor organoids on a microfluidic chip. The chip contains hundreds of lateral microwells and a surrounding pressure channel. Human colon tumor organoids growing in the microwell were cyclically contracted by pressure channel, mimicking the in vivo mechano-stimulus by intestinal muscles. The chip allows the control of peristalsis amplitude and rhythm and the high throughput culture of organoids simultaneously. By applying 8% amplitude with 8 ∼ 10 times min−1, we observed the enhanced expression of Lgr5 and Ki67. Moreover, ellipticine-loaded polymeric micelles showed reduced uptake in the organoids under peristalsis and resulted in compromised anti-tumor efficacy. The results indicate the importance of mechanical stimuli mimicking the physiological environment when using in vitro models to evaluate nanoparticles. This work provides a method for attaining more reliable and representative organoids models in nanomedicine.
Predicting Cohort-Specific Cervical Cancer Incidence From Population-Based Surveys of Human Papilloma Virus Prevalence: A Worldwide Study
Authors: Schulte-Frohlinde Rosa , Georges Damien , Clifford Gary M , Baussano Iacopo
Published: October 2021

Predictions of cervical cancer burden and the impact of measures taken to control this cancer are usually data-demanding and based on complex assumptions. We propose a predictive method (called PANDORA) based on human papillomavirus (HPV) prevalence, measured 1993–2008, and cervical cancer incidence (CCI), measured 1993–2012, in the same birth cohorts from different worldwide locations, informed by data on age at detection of high-risk HPV and sexual debut. The model can predict CCI among high-risk HPV–positive women and predict CCI up to 14 years following high-risk HPV detection. We found CCI to increase during the 14 years following high-risk HPV detection in unscreened women aged <35 years but to remain mainly constant among women ≥35 years. Age at sexual debut was a significant modifier of CCI. Using our model, we accurately reproduced CCI among high-risk HPV–positive women as observed in cohort studies and in the general population of multiple countries. We also predicted the annual number of cervical cancer cases and CCI in locations with HPV prevalence data but no cancer registry. These findings could inform cervical cancer control programs in settings without cancer registries, as they can be used to predict future cervical cancer burden from population-based surveys of HPV prevalence.
209 A Comparison of Soft Tissue Reactions Seen with Different Bone Anchored Hearing Aid Abutments: Smooth-Titanium Vs Hydroxyapatite-Coated
Authors: George R , Wasson J
Published: October 2021

Aim

Bone Anchored Hearing Aids allow hearing via stimulation of the cochlear through bone conduction. These devices are largely successful; however, soft tissue reactions often hinder their benefit. The type of abutment used could contribute to complications. We aimed to investigate whether using smooth-titanium abutments instead of hydroxyapatite-coated abutments reduced the rate of soft tissue reactions and need for revision surgery.

Method

A retrospective cohort analysis of all patients who received a Bone Anchored Hearing Aid during a 3-year period. An electronic database was screened for skin reactions and surgical revisions. A comparison was made between patients who received a hydroxyapatite-coated abutment and smooth-titanium abutments. The same surgical technique, linear incision skin preservation surgery, was used for inserting both abutments.

Results

Sixty-six patients received a Bone Anchored Hearing Aid. Forty-five patients received hydroxyapatite-coated abutments and twenty-one received smooth-titanium abutments, two patients had smooth-titanium inserted bilaterally. The groups were significantly similar with regards to age and gender. Significantly more patients who received hydroxyapatite-coated abutments recorded soft tissue reactions, 77.78% vs 23.81% (p < 0.0001). Significantly more patients who received hydroxyapatite-coated abutments required surgical revision, 40% vs 9.52% (p = 0.0197). 17.14% underwent skin revision and change of abutment. 5.7% had the abutments removed and were not immediately replaced.

Conclusions

When utilising skin preservation surgery for Bone Anchored Hearing Aid insertion smooth-titanium abutments have a favourable complication profile; with less soft tissue reactions and subsequent need for revision surgery, in comparison with hydroxyapatite-coated abutments. The reasons behind these differences warrant further investigations.
558 Summarising the Reporting of Outcomes in Studies of Robot Assisted Cholecystectomy: A Systematic Review
Authors: Jones C S , Kirkham E , Gourbault L , Hollowood F , Dada M , Baker W , Pathak S , Blencowe N ,   On behalf of the RoboSurg Collaborative
Published: October 2021

Background

Robot-assisted cholecystectomy (RC) has seen increasing adoption into clinical practice despite a lack of evidence to demonstrate superiority over conventional methods. Consistency in outcome selection, definition and reporting between studies is required for effective evidence synthesis and to minimise research waste. The aim of this study was to conduct an in-depth analysis of the outcomes reported in studies of RC. This work will inform the need for a core outcome set (COS).

Method

Systematic searches identified all published studies reporting RC, from inception to February 2020. Outcomes reported in each manuscript were recorded verbatim and categorised into domains. All outcomes were coded in duplicate. Where reported, the follow up period of each study was documented.

Results

Of 1425 abstracts screened, ninety studies met the criteria for inclusion. A total of 878 outcomes were reported. Each study included a median of 8 outcomes (range 3-26). Outcome selection was heterogeneous, with those relating to technical/operative factors (n = 383, 88 studies), complications (n = 245, 81 studies) and health economics (n = 139, 72 studies) used most frequently. No single outcome, or outcome domain, was reported in all studies. Only 30 studies reported a follow-up period, which ranged from 14 days to 46 months. In thirteen, the follow-up was for less than or equal to one month.

Conclusions

We identified significant heterogeneity in the selection and reporting of outcomes in studies of RC and support calls for standardisation and development of a COS.
1237 Optimising Outpatient Care After Paediatric Burns: The Development of a Chatbot To Identify Complications And Provide Clinical Advice
Authors: Geoghegan L , Harrison C , Collins D , Gardiner M , Rodrigues J
Published: October 2021

Aim

More than 6000 children require specialist care from one of fourteen regional burns services in England and Wales each year. Families often have to travel long distances and may not have access to specialist care with restricted services due to Covid-19. This quality improvement project aimed to:

Method

We conducted a national service evaluation of children’s burns services in England and Wales. We then conducted a PRISMA compliant systematic review up to September 2020 to identify studies reporting chatbot use to deliver outpatient care. A chatbot was then developed using Dialogflow to identify complications and provide advice to families.

Results

Across England and Wales, 11 children’s burns services reported outpatient practice: six services follow up all children at three months, three have variable follow-up and two discharge all patients. Our systematic review identified 10 studies reporting chatbot use although none were used following burns. A frame-based system-focused chatbot was developed in conjunction with expert burns surgeons and patient representatives.

Conclusions

Chatbots are effective and acceptable alternatives for in-person follow up. We demonstrate national variation in the provision of outpatient paediatric burn care and have developed a chatbot that can address clinical concerns and provide reassurance to patients and family members. Future studies will determine the acceptability and safety of this chatbot.
564 Freedom from Urethral Catherisation – Using QI Methodology to Improve Patient Outcome and Experiences
Authors: Odedra A , Allchorne P , Parker M , Lee J , Moyo-Gnahui S , Green J
Published: October 2021

Aim

To reduce catheter burden on patients who could instead be free of urethral catheter and taught intermittent self-catheterisation (ISC).

Method

2 PDSA (Plan, Do, Study, Act) cycles were performed over a 21-month period from February 2018 to November 2020. Using multiple nurse-led TWOC clinics, data was extracted using nurse-completed proformas and electronic patient records to determine: TWOC rate; urethral catheter-free rate; and ISC rate. Following baseline measurement, interventions were made, such as centralisation of TWOC services, emphasis on ISC teaching and the introduction of industry-nurse led clinics.

Results

At baseline, TWOC rate, urethral catheter-free rate and ISC rate were 55.7%, 68% and 28.2%, respectively. Following centralisation of TWOC services and emphasis on ISC teaching in Cycle 1, urethral catheter-free rate rose to 77.8% whilst ISC rate fell to 25%. Cycle 2 followed the introduction of industry-nurse led clinics. Following this, urethral catheter-free rate rose further to 81.6%, with ISC rate rising dramatically to 56.3%

Conclusions

To those capable, ISC frees patients of catheter burden and its sequalae. Evidently, a greater onus on ISC training will increase the number of patients left catheter-free.
1164 St Andrew’s COVID Surgery Safety (StACS) Study: Skin Cancer
Authors: Miranda B , Jica R , Pinto-Lopes R , Mopuri N , Sood M , Tare M , Shelley O , El-Muttardi N ,   St Andrew`s Collaborative
Published: October 2021

Background

Skin cancer represents the most common malignancy worldwide and it is imperative that we develop strategies to ensure safe and sustained delivery of cancer care which are resilient to the ongoing impact of COVID-19.

Objective

This study prospectively evaluates the COVID-19 related patient risk and skin cancer management at a single tertiary referral centre, which rapidly implemented national COVID-safety guidelines.

Method

A prospective cohort study was performed in all patients who underwent surgery for elective skin cancer service management, during the UK COVID-19 pandemic peak (April-May 2020). ‘Real-time’ 30-day hospital database deceased data were collected. Random selection was undertaken for patients who either underwent operative (surgery group) management or remained on the waiting list (control group); these groups were also prospectively followed-up within a controlled cohort study design and telephoned at the end of June 2020 for the control group or 30 days post-operatively.

Results

Of the 767 patients who had operations, there were no COVID-19 related deaths. Both the surgery (n = 384) and control (n = 100) groups were matched for age, sex, ethnicity, BMI, presence of comorbidities, smoking and positive COVID-19 contact. There were no differences in post-operative versus any symptom development (1.3%, 5/384 vs. 4%, 4/100, p = 0.093), or proportion of positive tests (8.6%, 33/384 vs. 8%, 8/100; p = 0.849), between the surgery and control groups.

Conclusions

These data support continued and safe service provision, and no increased risk to skin cancer patients who require surgical management, which is vital for continuation of cancer treatment in the context of a pandemic.
800 The Impact of the COVID-19 Pandemic on The Management of Patients with Vascular Conditions: The Vascular and Endovascular Research Network (VERN) COVID-19 Vascular Service (COVER) Tier 3 Study
Authors: Birmpili P ,   Vascular and Endovascular Research Network (VERN) COVER Study Collaborative
Published: October 2021

Introduction

The COVID-19 pandemic has had significant impact on healthcare delivery internationally. The aim of this study was to evaluate the changes in the management of vascular conditions during the COVID-19 pandemic compared to pre-pandemic standards.

Method

An international multicentre prospective cohort study was conducted over a 4-week period from March 2020. All patients referred to vascular services with acute vascular conditions were eligible to participate. Data on patient demographics, diagnosis and treatment delivered during the pandemic were collected. If there was a deviation from the pre-pandemic management plan, this ‘ideal’ plan was recorded, and the severity of modification scored on a 5-point scale.

Results

A total of 1801 patients from 52 centres in 19 countries were included in the study, most commonly referred with lower limb conditions (54.4%). Only 2.3% of patients had a confirmed diagnosis of COVID-19. A deviation from the pre-pandemic treatment standard occurred in 35% of unruptured ≥5.5cm diameter abdominal aortic aneurysms, 24.7% of patients with carotid disease, 17% with acute or chronic limb-threatening ischaemia and 12.7% with diabetic foot conditions. Of these modifications, 40.7% were significant, such as endovascular instead of open aneurysm repair or treatment delays, 38.1% major, such as non-operative management of carotid and lower limb disease, and 4.9% life-changing/ending including major amputation or palliation.

Conclusions

The COVID-19 pandemic has significantly impacted upon the management decisions for vascular conditions, independent of COVID status, with 17% of all-referred patients receiving suboptimal care due to limited resources and difficulty accessing services.
954 An International Multi-Centre Appraisal of The Management of Acute CHOLEcystitis During The COVID-19 Pandemic: The CHOLECOVID Study
Authors: Spiers H V M ,   CHOLECOVID Collaborative
Published: October 2021

Aim

National guidance issued in response to COVID-19 resulted in adoption of non-surgical modes of treatment in emergency surgery, including acute cholecystitis (AC). The aim of the CHOLECOVID Study is to understand the changes in management and outcomes of AC during COVID19, since becoming the definitive global study on the subject.

Method

Patients >18 years admitted to hospital with radiologically confirmed AC, during two predefined 8-week time periods: P1 (pre-pandemic) 12/09/19-12/11/19; P2 (during the pandemic) 12/03/20-12/05/20, were included. The primary outcome was 30-day all-cause mortality. Secondary outcomes included severity of AC, radiological diagnostic modalities implemented, definitive management and pulmonary complications.

Results

9,615 patients were included from 39 countries (P1:5,381; P2:4,234). 30-day mortality was higher in P2 (1.7%vs2.4%;p<0.015). Higher rates of moderate and severe AC were seen in P2 (30.1%vs35.1%;3.7%vs4.1%). First-line CT imaging was more common in P2 (36.3%vs46.3%;p<0.001). There were higher failure rates of conservative management in P2 (37.4% vs 44.4%; P < 0.001). Cholecystostomy rates were higher in P2 (5.8%vs8.8%;P<0.001). Overall, 4.6% (n = 193) of P2 patients were COVID-19 positive, with overall mortality of 0.7% (n = 30). There was no significant difference in pulmonary complications between COVID-19 positive or negative patients.

Conclusions

During the COVID-19 pandemic, a small increase in mortality among AC patients was noted, when compared to the pre-pandemic cohort. Patients during the COVID-19 pandemic presented with more severe AC, resulting in altered trends in diagnosis and management. New guidance and clear pathways are required to safely manage AC moving forward, in the face of further waves of COVID-19.
204 A Systematic Review of Clinical Outcomes for Outpatient vs Inpatient Shoulder Arthroplasty
Authors: Perera E , Flood B , Madden K , Goel D , Leroux T , Khan M
Published: October 2021

Aim

Outpatient shoulder arthroplasty is growing in popularity as a cost-effective and potentially equally safe alternative to inpatient arthroplasty. We investigated literature relating to outpatient shoulder arthroplasty, looking at clinical outcomes, complications, readmission, and cost compared to inpatient arthroplasty.

Method

We systematically searched Medline, Embase, PubMed using relevant search terms. Methodological quality of included studies was assessed using Methodological Index for Non-Randomised Studies score.

Results

We included 17 studies in our review with 11 included in the meta-analyses. A meta-analysis of hospital readmissions demonstrated that there was no statistically significant difference between outpatient and inpatient cohorts (OR = 0.89, 95% CI: 0.63-1.25, p = 0.49, I2=56%). Pooling results for all post-operative complications identified decreased complications in those undergoing outpatient surgery (OR = 0.70; 95% CI: 0.52-0.94, p = 0.02, I2=50%). No statistically significant difference was identified with respect to medical complications (OR = 0.86, 95% CI: 0.74-1.01, p = 0.07, I2=0%) or surgical complications (OR = 0.71, 95% CI: 0.45-1.12, p = 0.14, I2=26%). Considerable cost saving of between $3 614 – $53 202 (19.7 – 69.9%) per patient were present in the outpatient setting.

Conclusions

Shoulder arthroplasty in the outpatient setting is as safe as shoulder arthroplasty in the inpatient setting, with a significant reduction in cost. There is no demonstrable statistically significant difference with regards to readmissions between outpatient and inpatient shoulder arthroplasty. In the appropriately selected patient, outpatient shoulder arthroplasty is safe and cost-effective; however, we still need to work towards understanding who the appropriate patients are for this post-operative care pathway.
275 Validation of The Radiographic Union Score for Humeral Fractures (RUSHU) For Prediction of Humeral Shaft Nonunion
Authors: Arora N
Published: October 2021

Aim

To validate the use of RUSHu score in prediction of humerus non union.

Method

All patients having radiographs of humerus performed between Jan 2016 to December 2018 were assessed based on inclusion and exclusion criteria. The RUSHu scoring system as published was used to score each 6-week radiograph, separately by 2 blinded observers. 6 months was used as end point to assess outcome. Cohort of 188 observations were used to assess utility of scoring system to predict non union.

Results

94 suitable fractures were identified. Union rate of 72.3% was observed. Mean score in union group was 9.6, 6.4 for non-unions. There was substantial inter-observer reliability with an ICC of 0.73. Rate of union progressively increases with increasing RUSHu scores. ROC curve analysis identifies 8 as most suitable for use as threshold. Area under the curve is high (0.9)

Conclusions

A low RUSH score at 6 weeks is a reliable predictor of non union down the line. If a score 7 or lower is observed, it should trigger a discussion with the patient and review of correctable factors contributing to development of non union. Consideration of surgical fixation should be made at this stage if instability is felt to be a major contributing cause. A patient with score of 8 or higher is more likely to go on to union. Routine use of RUSHu score can aid in clinical decision making and introduce an element of objectivity in clinical assessment. It has potential to prompt earlier intervention and reduce morbidity duration.
328 Patellar Height After Anterior Cruciate Ligament Rupture Reconstruction Using the Autologous Bone-Patellar Tendon-Bone Graft Technique in The Maltese Population
Authors: Psaila R , Bugeja K
Published: October 2021

Aim

The primary aim of this study is to determine whether there is a change in patellar height after closure of the patellar tendon defect after a bone-patellar tendon-bone graft harvesting. The secondary aim is to evaluate clinical and functional outcomes.

Method

A retrospective observational study was conducted. Patients who were diagnosed with ACL injury and underwent reconstruction of ACL using the B-p-T-B graft technique from 2015 to 2020 were included (56 patients). All patients underwent the same procedural steps in the same centre. All patients had pre- and post-operative knee radiographs (antero-posterior and lateral views). The Caton- Deschamps Index was used to measure patellar height pre- and post-operatively. The International Knee Documentation Committee-Subjective Knee Evaluation Form was used to assess functional outcome. Clinical outcome was assessed by reviewing patient records.

Results

There was a change from the pre-op index 0.995 +/- 0.144 (mean +/- SD) to the post-op index 0.948 +/- 0.150. With a statistically significant decrease in index of 0.048 +/- 0.131 (p value 0.009) was found. The null hypothesis (that there is no change) is rejected and therefore the alternative hypothesis (a decrease in patellar height) is accepted. The mean IKDC-SKF score was 76.851 +/- 15.015 (SD) ranging from 40.2 to 100

Conclusions

Performing ACL reconstruction using the B-pT-B technique, although predisposing to a decreased patellar height, it does not increase the incidence of patella baja. An overall good functional outcome was achieved, mean IKDC-SKF 76.85. However, no clear association between change in patellar height and PF symptoms could be demonstrated.
Diagnostic accuracy using low-dose versus standard radiation dose CT in suspected acute appendicitis: prospective cohort study
Authors: Haijanen Jussi , Sippola Suvi , Tammilehto Ville , Grönroos Juha , Mäntyoja Siiri , Löyttyniemi Eliisa , Niiniviita Hannele , Salminen Paulina
Published: October 2021

Background

Contrast-enhanced CT is the reference standard used in diagnostic imaging for acute appendicitis in adults. The radiation dose has been of concern. This study aimed to assess whether a lower radiation dose would affect the diagnostic accuracy of CT.

Methods

This was a prospective single-centre cohort study of patients (aged over 16 years) with suspected appendicitis evaluated for enrolment in concurrent APPAC II–III trials. The diagnostic accuracy of contrast-enhanced low- and standard-dose CT was compared with study protocols guiding imaging based on BMI; this enabled direct CT imaging comparison only in patients with a BMI below 30 kg/m2. The on-call CT diagnosis was compared with the final clinical diagnosis.

Results

Among all 856 patients investigated, the accuracy of low-dose (454 patients) and standard-dose (402 patients) CT in identifying patients with and without appendicitis was 98·0 and 98·5 per cent respectively. In patients with a BMI under 30 kg/m2, respective values were 98·2 per cent (434 patients) and 98·6 per cent (210 patients) (P = 1·000). The corresponding accuracy for differentiating between uncomplicated and complicated acute appendicitis was 90·3 and 87·6 per cent in all patients, and 89·8 and 88·4 per cent respectively among those with a BMI below 30 kg/m2 (P = 0·663). The median radiation dose in the whole low- and standard-dose CT groups was 3 and 7 mSv respectively. In the group with BMI below 30 kg/m2, corresponding median doses were 3 and 5 mSv (P < 0·001).

Conclusion

Low- and standard-dose CT were accurate both in identifying appendicitis and in differentiating between uncomplicated and complicated acute appendicitis. Low-dose CT was associated with a significant radiation dose reduction, suggesting that it should be standard clinical practice at least in patients with a BMI below 30 kg/m2.
The Key-Dependent Capacity in Multidimensional Linear Cryptanalysis
Authors: Cao Wenqin , Zhang Wentao , Zhao Xuefeng
Published: October 2021

The capacity is an important parameter in multidimensional linear attack. In this paper, we firstly explore the distribution of the key-dependent capacity. Based on the magnitude of the correlation contributions, we divide the linear approximations subspace into two sets: one set consists of the strong linear approximations, and the other set consists of the weak linear approximations. We construct two statistics using the linear approximations in the two sets, respectively. Under reasonable assumptions, both of the two statistics follow Gamma distribution. Thus, the capacity is the sum of two statistics that follow Gamma distribution. Secondly, the accuracy of the model is verified by experiments on SMALLPRESENT[4]. Our experimental results show that this model can estimate the variance of the key-dependent capacity more accurately. Thus, we obtain more precise knowledge of the data complexity of the multidimensional linear attack. We derive the upper bound of the data complexity for multidimensional linear attack. Finally, based on our theoretical results, we explore the data complexity of Cho’s multidimensional linear attack on PRESENT. Our results are the smallest data complexity for the same round attack so far.
SR-Mitochondria Crosstalk Shapes Ca Signalling to Impact Pathophenotype in Disease Models Marked by Dysregulated Intracellular Ca Release
Authors: Tow Brian D , Deb Arpita , Neupane Shraddha , Patel Shuchi M , Reed Meagan , Loper Anna-Beth , Eliseev Roman A , Knollmann Björn C , Györke Sándor , Liu Bin
Published: October 2021

Aims

Diastolic Ca release (DCR) from sarcoplasmic reticulum (SR) Ca release channel ryanodine receptor (RyR2) has been linked to multiple cardiac pathologies, but its exact role in shaping divergent cardiac pathologies remains unclear. We hypothesize that the SR-mitochondria interplay contributes to disease phenotypes by shaping Ca signalling.

Methods and results

A genetic model of catecholaminergic polymorphic ventricular tachycardia (CPVT2 model of CASQ2 knockout) and a pre-diabetic cardiomyopathy model of fructose-fed mice (FFD), both marked by DCR, are employed in this study. Mitochondria Ca (mCa) is modulated by pharmacologically targeting mitochondria Ca uniporter (MCU) or permeability transition pore (mPTP), mCa uptake, and extrusion mechanisms, respectively. An MCU activator abolished Ca waves in CPVT2 but exacerbated waves in FFD cells. Mechanistically this is ascribed to mitochondria’s function as a Ca buffer or source of reactive oxygen species (mtROS) to exacerbate RyR2 functionality, respectively. Enhancing mCa uptake reduced and elevated mtROS production in CPVT2 and FFD, respectively. In CPVT2, mitochondria took up more Ca in permeabilized cells, and had higher level of mCa content in intact cells vs. FFD. Conditional ablation of MCU in the CPVT2 model caused lethality and cardiac remodelling, but reduced arrhythmias in the FFD model. In parallel, CPVT2 mitochondria also employ up-regulated mPTP-mediated Ca efflux to avoid mCa overload, as seen by elevated incidence of MitoWinks (an indicator of mPTP-mediated Ca efflux) vs. FFD. Both pharmacological and genetic inhibition of mPTP promoted mtROS production and exacerbation of myocyte Ca handling in CPVT2. Further, genetic inhibition of mPTP exacerbated arrhythmias in CPVT2.

Conclusion

In contrast to FFD, which is more susceptible to mtROS-dependent RyR2 leak, in CPVT2 mitochondria buffer SR-derived DCR to mitigate Ca-dependent pathological remodelling and rely on mPTP-mediated Ca efflux to avoid mCa overload. SR-mitochondria interplay contributes to the divergent pathologies by disparately shaping intracellular Ca signalling.
Genetic inhibition of nuclear factor of activated T-cell c2 prevents atrial fibrillation in CREM transgenic mice
Authors: Ni Li , Lahiri Satadru K , Nie Jiali , Pan Xiaolu , Abu-Taha Issam , Reynolds Julia O , Campbell Hannah M , Wang Haihao , Kamler Markus , Schmitz Wilhelm , Müller Frank Ulrich , Li Na , Wei Xiang , Wang Dao Wen , Dobrev Dobromir , Wehrens Xander H T
Published: October 2021

Aims

Abnormal intracellular calcium (Ca2+) handling contributes to the progressive nature of atrial fibrillation (AF), the most common sustained cardiac arrhythmia. Evidence in mouse models suggests that activation of the nuclear factor of activated T-cell (NFAT) signalling pathway contributes to atrial remodelling. Our aim was to determine the role of NFATc2 in AF in humans and mouse models.

Methods and results

Expression levels of NFATc1–c4 isoforms were assessed by quantitative reverse transcription–polymerase chain reaction in right atrial appendages from patients with chronic AF (cAF). NFATc1 and NFATc2 mRNA levels were elevated in cAF patients compared with those in normal sinus rhythm (NSR). Western blotting revealed increased cytosolic and nuclear levels of NFATc2 in AF patients. Similar findings were obtained in CREM-IbΔC-X transgenic (CREM) mice, a model of progressive AF. Telemetry ECG recordings revealed age-dependent spontaneous AF in CREM mice, which was prevented by NFATc2 knockout in CREM:NFATc2–/– mice. Programmed electrical stimulation revealed that CREM:NFATc2–/– mice lacked an AF substrate. Morphometric analysis and histology revealed increased atrial weight and atrial fibrosis in CREM mice compared with wild-type controls, which was reversed in CREM:NFATc2–/– mice. Confocal microscopy showed an increased Ca2+ spark frequency despite a reduced sarcoplasmic reticulum (SR) Ca2+ load in CREM mice compared with controls, whereas these abnormalities were normalized in CREM:NFATc2–/– mice. Western blotting revealed that genetic inhibition of Ca2+/calmodulin-dependent protein kinase II-mediated phosphorylation of S2814 on ryanodine receptor type 2 (RyR2) in CREM:RyR2-S2814A mice suppressed NFATc2 activation observed in CREM mice, suggesting that NFATc2 is activated by excessive SR Ca2+ leak via RyR2. Finally, chromatin immunoprecipitation sequencing from AF patients identified Ras and EF-hand domain-containing protein (Rasef) as a direct target of NFATc2-mediated transcription.

Conclusion

Our findings reveal activation of the NFAT signalling pathway in patients of Chinese and European descent. NFATc2 knockout prevents the progression of AF in the CREM mouse model.