bluuebunny/crossref_metadata_2025 huggingface dataset:
Stellar limits on light CP-even scalar
Authors: Bhupal Dev P.S. , Mohapatra Rabindra N. , Zhang Yongchao
Published: May 2021

We revisit the astrophysical constraints on a generic light CP-even scalar particle S, mixing with the Standard Model (SM) Higgs boson, from observed luminosities of the Sun, red giants, white dwarfs and horizontal-branch stars. The production of S in the stellar core is dominated by the electron-nuclei bremsstrahlung process e + N → e + N + S. With the S decay and reabsorption processes taken into consideration, we find that the stellar luminosity limits exclude a broad range of parameter space in the S mass-mixing plane, with the scalar mass up to 350 keV and the mixing angle ranging from 7.0 × 10-18 to 3.4 × 10-3. We also apply the stellar limits to a real-singlet scalar extension of the SM, where we can relate the mixing angle to the parameters in the scalar potential. In both the generic scalar case and the real-singlet extension, we show that the stellar limits preclude the scalar interpretation of the recently observed XENON1T excess in terms of the S particles emitted from the Sun.
Mass varying neutrinos with different quintessence potentials
Authors: Mandal Sayan , Chitov Gennady Y. , Avsajanishvili Olga , Singha Bijit , Kahniashvili Tina
Published: May 2021

The mass-varying neutrino scenario is analyzed for three trial quintessence potentials (Ferreira-Joyce, inverse exponential,
and thawing oscillating).
The neutrino mass is generated via Yukawa coupling to the scalar field which represents dark energy.
The inverse exponential and oscillating potentials are shown to successfully generate the neutrino masses in the range m ∼ 10-2-10-3 eV
and to yield the current dark energy density in the regime of the late-time acceleration of the Universe.
Depending on the choice of potentials, the acceleration could occur in two different regimes:
(1) the regime of instability, and (2) the stable regime. The first regime of instability is after the Universe underwent a first-order transition and is rolling toward the new stable vacuum. The imaginary sound velocity c2
s < 0 in this regime implies growing fluctuations of the neutrino density (clustering). In the second regime, the Universe smoothly changes its stable states via a continuous transition. Since c2
s > 0, the neutrino density is stable.
For all cases the predicted late-time acceleration of the Universe is asymptotically very close to that of the ΛCDM model.
Further extensions of the theory to modify the neutrino sector of the Standard Model and to incorporate inflation are also discussed.
It is also shown that in the stable regimes where the neutrino mass is given by the minimum of the thermodynamic potential, the tree-level dynamics of the scalar field is robust with respect to one-loop bosonic and fermionic corrections to the potential.
One-dimensional atom laser in microgravity*
Authors: Qin Yi , Shen Xiaoyang , Xia Lin
Published: May 2021

Using coupled Gross–Pitaevksii (GP) equations, we simulate the output of one-dimensional pulsed atom laser in space station. We get two atom laser pulses propagating in opposite directions with one pulsed RF coupling. Compared with atom laser under gravity, the laser pulse in microgravity shows much slower moving speed, which is suitable to be used for long-term investigations. We also simulate the output flux at different coupling strengths.
Thermal and mechanical properties and micro-mechanism of SiO2/epoxy nanodielectrics*
Authors: Wang Tian-Yu , Zhang Gui-Xin , Li Da-Yu
Published: May 2021

In addition to electrical insulation properties, the thermal properties of nanodielectrics, such as glass transition temperature, thermal expansion coefficients, thermal conductivity, and mechanical properties, including Young’s modulus, bulk modulus, and shear modulus, are also very important. This paper describes the molecular dynamics simulations of epoxy resin doped with SiO2 nanoparticles and with SiO2 nanoparticles that have been surface grafted with hexamethyldisilazane (HMDS) at 10% and 20% grafting rates. The results show that surface grafting can improve certain thermal and mechanical properties of the system. Our analysis indicates that the improved thermal performance occurs because the formation of thermal chains becomes easier after the surface grafting treatment. The improved mechanical properties originate from two causes. First, doping with SiO2 nanoparticles inhibits the degree of movement of molecular chains in the system. Second, the surface grafting treatment weakens the molecular repulsion between SiO2 and epoxy resin, and the van der Waals excluded region becomes thinner. Thus, the compatibility between SiO2 nanoparticles and polymers is improved by the grafting treatment. The analysis method and conclusions in this paper provide guidance and reference for the future studies of the thermal and mechanical properties of nanodielectrics.
A double quantum dot defined by top gates in a single crystalline InSb nanosheet*
Authors: Chen Yuanjie , Huang Shaoyun , Mu Jingwei , Pan Dong , Zhao Jianhua , Xu Hong-Qi
Published: May 2021

We report on the transport study of a double quantum dot (DQD) device made from a freestanding, single crystalline InSb nanosheet. The freestanding nanosheet is grown by molecular beam epitaxy and the DQD is defined by the top gate technique. Through the transport measurements, we demonstrate how a single quantum dot (QD) and a DQD can be defined in an InSb nanosheet by tuning voltages applied to the top gates. We also measure the charge stability diagrams of the DQD and show that the charge states and the inter-dot coupling between the two individual QDs in the DQD can be efficiently regulated by the top gates. Numerical simulations for the potential profile and charge density distribution in the DQD have been performed and the results support the experimental findings and provide a better understanding of fabrication and transport characteristics of the DQD in the InSb nanosheet. The achieved DQD in the two-dimensional InSb nanosheet possesses pronounced benefits in lateral scaling and can thus serve as a new building block for the developments of quantum computation and quantum simulation technologies.
Analysis of the rogue waves in the blood based on the high-order NLS equations with variable coefficients*
Authors: Yang Ying , Gao Yu-Xiao , Yang Hong-Wei
Published: May 2021

The research of rogue waves is an advanced field which has important practical and theoretical significances in mathematics, physics, biological fluid mechanics, oceanography, etc. Using the reductive perturbation theory and long wave approximation, the equations governing the movement of blood vessel walls and the flow of blood are transformed into high-order nonlinear Schrödinger (NLS) equations with variable coefficients. The third-order nonlinear Schrödinger equation is degenerated into a completely integrable Sasa–Satsuma equation (SSE) whose solutions can be used to approximately simulate the real rogue waves in the vessels. For the first time, we discuss the conditions for generating rogue waves in the blood vessels and effects of some physiological parameters on the rogue waves. Based on the traveling wave solutions of the fourth-order nonlinear Schrödinger equation, we analyze the effects of the higher order terms and the initial deformations of the blood vessel on the wave propagation and the displacement of the tube wall. Our results reveal that the amplitude of the rogue waves are proportional to the initial stretching ratio of the tube. The high-order nonlinear and dispersion terms lead to the distortion of the wave, while the initial deformation of the tube wall will influence the wave amplitude and wave steepness.
MoO3–MoS2vertical heterostructures synthesized via one-step CVD process for optoelectronics
Authors: Guo Yuxi , Kang Lixing , Song Pin , Zeng Qingsheng , Tang Bijun , Yang Jiefu , Wu Yao , Tian Dan , Xu Manzhang , Zhao Wu , Qi Xiaofei , Zhang Zhiyong , Liu Zheng
Published: May 2021

The 2D transitional metal oxides/transition-metal dichalcogenides vertical heterostructures of MoO3–MoS2are successfully synthesized on SiO2/Si substrates via one-step chemical vapor deposition process. The vertical MoO3–MoS2heterostructures exhibit the average size of ∼20μm and the thickness down to ∼10 nm. Moreover, the phototransistor device based on MoO3–MoS2heterostructures presents responsivity of 5.41 × 103A W−1, detectivity of 0.89 × 1010Jones and external quantum efficiency of 1263.4%, respectively, under a 532 nm wavelength light. This study affords a new path to simplify process of fabricating MoO3–MoS2vertical heterostructures for electronic and optoelectronic applications.
Study of machining indentations over the entire surface of a target ball using the force modulation approach
Authors: Wang Yuzhang , Geng Yanquan , Li Guo , Wang Jiqiang , Fang Zhuo , Yan Yongda
Published: May 2021

A modified five-axis cutting system using a force control cutting strategy was to machine indentations in different annuli on the entire surface of a target ball. The relationship between the cutting depths and the applied load as well as the microsphere rotation speed were studied experimentally to reveal the micromachining mechanism. In particular, aligning the rotating center of the high precision spindle with the microsphere center is essential for guaranteeing the machining accuracy of indentations. The distance between adjacent indentations on the same annulus and the vertical distance between adjacent annuli were determined by the rotating speed of the micro-ball and the controllable movement of the high-precision stage, respectively. In order to verify the feasibility and effect of the proposed cutting strategy, indentations with constant and expected depths were conducted on the entire surface of a hollow thin-walled micro-ball with a diameter of 1 mm. The results imply that this machining methodology has the potential to provide the target ball with desired modulated defects for simulating the inertial confinement fusion implosion experiment.
Research progress on preparation technology of oxide dispersion strengthened steel for nuclear energy
Authors: Wang Jianqiang , Liu Sheng , Xu Bin , Zhang Jianyang , Sun Mingyue , Li Dianzhong
Published: May 2021

Nuclear energy is a low-carbon, safe, efficient, and sustainable clean energy. The new generation of nuclear energy systems operate in harsher environments under higher working temperatures and irradiation doses, while traditional nuclear power materials cannot meet the requirements. The development of high-performance nuclear power materials is a key factor for promoting the development of nuclear energy. Oxide dispersion strengthened (ODS) steel contains a high number density of dispersed nano-oxides and defect sinks and exhibits excellent high temperature creep performance and irradiation swelling resistance. Therefore, ODS steel has been considered as one of the most promising candidate materials for fourth-generation nuclear fission reactor cladding tubes and nuclear fusion reactor blankets. The preparation process significantly influences microstructure of ODS steel. This paper reviews the development and perspective of several preparation processes of ODS steel, including the powder metallurgy process, improved powder metallurgy process, liquid metal forming process, hybrid process, and additive forging. This paper also summarizes and analyzes the relationship between microstructures and the preparation process. After comprehensive consideration, the powder metallurgy process is still the best preparation process for ODS steel. Combining the advantages and disadvantages of the above preparation processes, the trend applied additive forging for extreme manufacturing of large ODS steel components is discussed with the goal of providing a reference for the application and development of ODS steel in nuclear energy.
Cellsnp-lite: an efficient tool for genotyping single cells
Authors: Huang Xianjie , Huang Yuanhua
Published: May 2021

Single-cell sequencing is an increasingly used technology and has promising applications in basic research and clinical translations. However, genotyping methods developed for bulk sequencing data have not been well adapted for single-cell data, in terms of both computational parallelization and simplified user interface. Here, we introduce a software, cellsnp-lite, implemented in C/C++ and based on well-supported package htslib, for genotyping in single-cell sequencing data for both droplet and well-based platforms. On various experimental datasets, it shows substantial improvement in computational speed and memory efficiency with retaining highly concordant results compared to existing methods. Cellsnp-lite, therefore, lightens the genetic analysis for increasingly large single-cell data.

Availability and implementation

The source code is freely available at https://github.com/single-cell-genetics/cellsnp-lite.

Supplementary information

Supplementary data are available at Bioinformatics online.
Microvesicles and exosomes released by amnion epithelial cells under oxidative stress cause inflammatory changes in uterine cells†
Authors: Shahin Hend I , Radnaa Enkhtuya , Tantengco Ourlad Alzeus G , Kechichian Talar , Kammala Ananth Kumar , Sheller-Miller Samantha , Taylor Brandie D , Menon Ramkumar
Published: May 2021

Extracellular vesicles play a crucial role in feto-maternal communication and provide an important paracrine signaling mechanism in pregnancy. We hypothesized that fetal cells-derived exosomes and microvesicles (MVs) under oxidative stress (OS) carry unique cargo and traffic through feto-maternal interface, which cause inflammation in uterine cells associated with parturition. Exosomes and MVs, from primary amnion epithelial cell (AEC) culture media under normal or OS-induced conditions, were isolated by optimized differential centrifugation method followed by characterization for size (nanoparticle tracking analyzer), shape (transmission electron microscopy), and protein markers (western blot and immunofluorescence). Cargo and canonical pathways were identified by mass spectroscopy and ingenuity pathway analysis. Myometrial, decidual, and cervical cells were treated with 1 × 107 control/OS-derived exosomes/MVs. Pro-inflammatory cytokines were measured using a Luminex assay. Statistical significance was determined by paired T-test (P < 0.05). AEC produced cup-shaped exosomes of 90–150 nm and circular MVs of 160–400 nm. CD9, heat shock protein 70, and Nanog were detected in exosomes, whereas OCT-4, human leukocyte antigen G, and calnexin were found in MVs. MVs, but not exosomes, were stained for phosphatidylserine. The protein profiles for control versus OS-derived exosomes and MVs were significantly different. Several inflammatory pathways related to OS were upregulated that were distinct between exosomes and MVs. Both OS-derived exosomes and MVs significantly increased pro-inflammatory cytokines (granulocyte-macrophage colony-stimulating factor, interleukin 6 (IL-6), and IL-8) in maternal cells compared with control (P < 0.05). Our findings suggest that fetal-derived exosomes and MVs under OS exhibited distinct characteristics and a synergistic inflammatory role in uterine cells associated with the initiation of parturition.
Neither gonadotropin nor cumulus cell expansion is needed for the maturation of competent porcine oocytes in vitro†
Authors: Redel Bethany K , Spate Lee D , Yuan Ye , Murphy Clifton N , Roberts R Michael , Prather Randall S
Published: May 2021

In-vitro maturation (IVM) of oocytes from immature females is widely used in assisted reproductive technologies. Here we illustrate that cumulus cell (CC) expansion, once considered a key indicator of oocyte quality, is not needed for oocytes to mature to the metaphase II (MII) stage and to gain nuclear and cytoplasmic competence to produce offspring. Juvenile pig oocytes were matured in four different media: (1) Basal (−gonadotropins (GN) − FLI); (2) −GN + FLI (supplement of FGF2, LIF, and IGF1); (3) +GN − FLI; and (4) +GN + FLI. There was no difference in maturation to MII or progression to the blastocyst stage after fertilization of oocytes that had been matured in −GN + FLI medium and oocytes matured in +GN + FLI medium. Only slight CC expansion occurred in the two media lacking GN compared with the two where GN was present. The cumulus-oocytes-complexes (COC) matured in +GN + FLI exhibited the greatest expansion. We conclude that FLI has a dual role. It is directly responsible for oocyte competence, a process where GN are not required, and, when GN are present, it has a downstream role in enhancing CC expansion. Our study also shows that elevated phosphorylated MAPK may not be a necessary correlate of oocyte maturation and that the greater utilization of glucose by COC observed in +GN + FLI medium probably plays a more significant role to meet the biosynthetic needs of the CC to expand than to attain oocyte developmental competence. Gene expression analyses have not been informative in providing a mechanism to explain how FLI medium enhances oocyte competence without promoting CC expansion.
Influence of estradiol on bovine trophectoderm and uterine gene transcripts around maternal recognition of pregnancy
Authors: Northrop-Albrecht Emmalee J , Rich Jerica J J , Cushman Robert A , Yao Runan , Ge Xijin , Perry George A
Published: May 2021

Embryo survival and pregnancy success is increased among animals that exhibit estrus prior to fixed time-artificial insemination, but there are no differences in conceptus survival to d16. The objective of this study was to determine effects of preovulatory estradiol on uterine transcriptomes, select trophectoderm (TE) transcripts, and uterine luminal fluid proteins. Beef cows/heifers were synchronized, artificially inseminated (d0), and grouped into either high (highE2) or low (lowE2) preovulatory estradiol. Uteri were flushed (d16); conceptuses and endometrial biopsies (n = 29) were collected. RNA sequencing was performed on endometrium. Real-time polymerase chain reaction (RT-PCR) was performed on TE (n = 21) RNA to measure relative abundance of IFNT, PTGS2, TM4SF1, C3, FGFR2, and GAPDH. Uterine fluid was analyzed using 2D Liquid Chromatography with tandem mass spectrometry-based Isobaric tags for relative and absolute quantitation (iTRAQ) method. RT-PCR data were analyzed using the MIXED procedure in SAS. There were no differences in messenger RNA (mRNA) abundances in TE, but there were 432 differentially expressed genes (253 downregulated, 179 upregulated) in highE2/conceptus versus lowE2/conceptus groups. There were also 48 differentially expressed proteins (19 upregulated, 29 downregulated); 6 of these were differentially expressed (FDR < 0.10) at the mRNA level. Similar pathways for mRNA and proteins included: calcium signaling, protein kinase A signaling, and corticotropin-releasing hormone signaling. These differences in uterine function may be preparing the conceptus for improved likelihood of survival after d16 among highE2 animals.
18 Manipulation Under Anaesthetic for Frozen Shoulder: Does Post-Operative Supervised Physiotherapy Affect the Outcome?
Authors: Castelhano R , Woods J , Akehurst H , Mitra A , James M , Tasker A , Woods D
Published: May 2021

Introduction

This study compares two pathways for patients undergoing MUA for FS, one where physiotherapy advice is only given to the patient (Group 1), and the other where supervised hydrotherapy and physiotherapy occur post operatively (Group 2).

Method

A descriptive analysis of pre- and post-operative Oxford Shoulder Scores and change scores were performed.

Analysis of covariance (ANCOVA) was used to measure the effect of physiotherapy on post-operative OSS, with pre-operative OSS as the only covariate.

Results

The results for post-operative OSS were significantly greater for Group 2 than for Group 1 (40.7 for NHS and 44.7 for private, improvement of 17.32 for NHS and 18.23 for Private). The estimated effect of physiotherapy on postoperative OSS was an increase of 3.2 (95% confidence interval 1.5 – 4.8).

Conclusions

We detected a statistically significant increase in post-operative OSS in patients treated for frozen shoulder with MUA + physiotherapy compared with patients receiving MUA plus advice alone. These results suggest that physiotherapy does confer a real benefit, however the increased OSS is below the clinically significant level. Therefore, in a resource poor environment, such as may exist after COVID in many health care systems, MUA plus physio advice alone gives an excellent outcome for the treatment of FS.
223 The Clinical Applications of Machine Learning in Plastic and Reconstructive Surgery: A Systematic Review
Authors: Mantelakis A
Published: May 2021

Background

Machine learning (ML) is a set of models and methods that can automatically detect patterns in vast amounts of data and use this information to perform various kinds of decision-making under uncertain conditions. The aim of this review is to evaluate the applications of machine learning in plastic and reconstructive surgery.

Method

EMBASE, MEDLINE and CENTRAL were searched from 1990 to 2020 for studies in which machine learning has been employed in the clinical setting of reconstructive surgery. Primary outcomes will be the evaluation of the accuracy of machine learning models in predicting a clinical diagnosis and post-surgical outcomes.

Results

The database identified 1181 articles, of which 51 articles were included in this review. The clinical utility of these algorithms was to assist clinicians in diagnosis prediction (n = 22), outcome prediction (n = 21) and pre-operative planning (n = 8). The mean accuracy for diagnosis prediction, outcome prediction and pre-operative planning was 88.80%, 86.11% and 80.28% respectively. The most commonly used models were neural networks (n = 31), support vector machine (n = 13), decision trees/random forests (10) and logistic regression (n = 9).

Discussion

ML has demonstrated excellent performance in diagnosis and outcome predictions, but it is still in its infancy. Further research is warranted to evaluate its applications.
616 Preventing Biofilms on BACTIGON® Coated Camstent Urinary Catheters in Patients Undergoing Elective Colorectal Surgery: A Single Centre Pilot Study
Authors: Lewis-Lloyd C , Dubern J , Kalenderski K , Halliday N , Alexander M , Irvine D , Adiamah A , Williams P , Hume D
Published: May 2021

Introduction

Catheter associated urinary tract infections account for 40% of hospital acquired infections. They are associated with biofilms consisting of bacterial cells enmeshed in a self-generated extracellular matrix adhering to catheter surfaces. We have developed a novel polymer family that, coated onto urinary catheters, creates a “non-stick” surface preventing biofilm development.

Method

Prospective cohort of elective colorectal patients recruited pre-operatively, received a standard silicone (SS) or Camstent (BACTIGON®) coated urinary catheter. After removal, catheters were cut longitudinally into 3 segments. Biomass and biomineralisation were analysed using confocal fluorescence microscopy. Data were normalised by square rooting the catheter indwelling duration. Environmental scanning electron microscopy and energy dispersive x-ray spectroscopy was performed.

Results

Of 40 patients, 20 each received a SS or coated catheter. Between SS and coated catheters, average indwelling duration was similar and biofilm biomass was 32.068µg/cm2 (95%CI ±21.950) vs. 1.948µg/cm2 (95%CI ±2.595) (P = 0.0111). Confocal microscopy suggested a 93.93% reduction in biofilm biomass on coated catheters. Mineral compositions were different with biofilm and struvite/apatite on SS and calcium oxalate, endogenously derived, on coated catheters.

Conclusions

Inert BACTIGON® coated catheters appear superior at preventing biofilm formation than SS catheters. Clinical trials are needed to determine the clinical and health economic benefit of this intervention.
666 Innovations in ENT Surgery During The COVID-19 Pandemic
Authors: Aziz M , Benamer M , Hany S , Sahib Y
Published: May 2021

Introduction

Severe acute respiratory syndrome coronavirus 2 (SARS-COV-2), is responsible for the coronavirus disease 2019 (COVID – 19) global pandemic. Similar coronavirus epidemics over the past years affected healthcare workers significantly. Aerosol generating procedures (AGPs) presented a unique risk to ear, nose and throat (ENT) Surgeons. We introduce various methods of reducing risk in ENT AGPs.

Recommendations

During trachesostomies we advocate the adoption of a specialist checklist based on ENT UK guidelines.

We also advise the use of a clear drape to create a clear barrier between the patient and staff.

For ear surgery we advise suturing 2 microscope pieces together end-to-end so that a clear drape can sperate the patient from surgeon.

During nasal and sinus surgery, we advise attaching a clear drape to the sterile camera drape used in rigid nasal endoscopy to create a barrier between patient and surgeon.

Discussion

Our recommendations will create an extra barrier between the patient and the rest of healthcare team. This should reduce the risks to theatre staff from AGPs.

Conclusions

COVID 19 is a serious health issue affecting healthcare workers, especially during AGPs in ENT surgery. We recommend several techniques to reduce risk. These can also be used during future epidemics.
906 Implementing and Re-Designing A Virtual Fracture Clinic (VFC) During The COVID-19 Pandemic
Authors: Erotocritou M , Overton A , Ang W W , Walker M , Burns S , Berber O
Published: May 2021

Introduction

We have implemented a VFC model during the COVID-19 pandemic to minimise the number of face-to-face consultations and the risk of transmission.

Method

The VFC was implemented and assessed using 3 PDSA cycles. Initially, a paper referral system was introduced along with treatment pathways. Subsequently an electronic referral system was established. The 3rd PDSA cycle involved training A&E staff on referrals and treatment pathways. At each stage the number of VFC referrals and clinic follow-ups were measured. Patient satisfaction was assessed using a telephone survey with a random sample of 30 patients.

Results

There was a statistically significant reduction in face-to-face follow-ups between pre-VFC (Total:4083, Average:86.87) and post-VFC (Total:713, Average:35.65) p-value<0.0001. There was a statistically significant increase in patient satisfaction after the implementation of the electronic referral system and staff re-training(9.25) compared to paper referrals(8.23), p-value=0.02064.

Conclusions

Our study demonstrated that the VFC successfully reduced the number of face-to-face follow-ups while maintaining patient satisfaction. Thus, it is an effective alternative to conventional fracture clinics. A similar model can be introduced at other hospitals to minimise in-person consultations and risk of transmission, while standardising patient care. It has also highlighted the importance of appropriate technological infrastructure, staff training and service evaluation.
26 COVID-19 Diagnosis in Patients with Acute Abdominal Pain Without Respiratory Symptoms: A UK Emergency General Surgical Unit Experience
Authors: Zuberi S , Mushtaq Y , Patel K , Vickramarajah S , Askari A , Rashid F , Gurprashad R
Published: May 2021

Introduction

Evidence has emerged reporting atypical symptoms of the coronavirus (COVID-19). There is a sparsity of existing studies examining COVID-19 related abdominal pain and the role of investigative imaging for the virus in these patients. Study aims were to determine COVID-19 incidence in those with acute abdominal pain in the absence of respiratory symptoms and to assess the performance of Computer Tomography (CT) thoracic imaging.

Method

Retrospective analysis of all patients admitted to our emergency general surgical unit between 1st March 2020 and 31st May 2020 was performed. All patients underwent nasal and oro-pharyngeal COVID-19 RT-PCR swabs as well as CT on admission.

Results

From 112 patients admitted with acute abdominal pain in the absence of respiratory symptoms, 16 (14.3%) tested positive for COVID-19 on RT-PCR swab testing. 50% (8/16) of these patients had no intra-abdominal pathology on CT. The sensitivity and specificity of CT thoracic imaging for COVID-19 was 43.8% and 91.7%.

Conclusions

One in seven patients with abdominal pain without any respiratory symptoms tested positive. Half these patients represented COVID-19 manifesting primarily as acute abdominal pain. Combined swab testing and CT imaging should be performed in all abdominal pain presentations due to the varying diagnostic performance of thoracic CT in diagnosing COVID-19.
88 Prevalence Of SARS-COVID-19 Serum Igg Antibodies Amongst Staff on An Acute Surgical Unit
Authors: Isheerwood J , Winyard J , Bekhyat Karki B , Chung W Y , Layton G , Issa E , Garcea G , Dennison A
Published: May 2021

Background

The United Kingdom now has one of the highest death rates from COVID 19, with over 40,000 deaths (1). It has been posited that the identification of care workers with immunity or increased resistance could be important in developing future strategies.

Method

This was a retrospectively conducted survey of general surgical staff at a tertiary surgical unit.

Results

We surveyed 215 staff that had undergone antibody testing. Of the 175/215 who reported contact with COVID-19 positive patients, 6/215 had a positive PCR result and 15/215 reported a positive antibody test. Only 3/6 that had a positive PCR test demonstrated antibodies.

Conclusions

Our “immunity” rate of 7% is extremely low and is concerning especially in respect of the anticipated “herd immunity” which would mitigate many of the issues presently being confronted and it is likely to be many months at least before this makes realistic contribution. Continued testing for the presence of COVID-19 antibodies will contribute to crucial seroprevalence data that can be used by public health bodies whose advice will necessarily evolve as increasing data sets become available.
198 Orthopaedic Trauma Services During A National Lockdown and Pandemic: Workload and Outcomes from A UK Major Trauma Centre. The Need for Continuing the Provision of Services
Authors: Donovan R , Tilston T , Frostick R , Chesser T
Published: May 2021

Aim

To review the trauma operating workload, theatre time and outcomes at a time of national lockdown and the beginning of the COVID-19 pandemic, comparing it with 2019.

Method

A retrospective analysis at a single UK MTC. We included all patients undergoing emergency/urgent T&O surgery. Data collected included anatomical injury site, mechanism of injury, operative procedure, anaesthesia, theatre time, complications, and 30-day mortality.

Results

159 operations were performed on 142 patients in April 2019, and 110 operations on 106 patients in April 2020 (national lockdown). This led to a decrease of 30% due to reduced numbers from RTAs and sport-related injuries. Volumes of hip fractures and injuries from low-energy falls remained the same. Operative total theatre time increased by a mean of 14 minutes, and complications and mortality were not significantly changed. The incidence of COVID-19 in the patients tested was 8.5%, which matched the population incidence at the time.

Conclusion

Orthopaedic trauma services must be maintained during a national lockdown. There is no decrease in the volume of patients sustaining falls, including hip fractures. Mean operating time only increases by 14 minutes with the wearing of PPE. This should be part of future planning of any pandemics or national lockdowns.
263 Airway, Voice and Swallow Outcomes Following Endotracheal Intubation and Mechanical Ventilation For COVID-19 Pneumonitis: Preliminary Results of a Prospective Cohort Study
Authors: Miu K , Miller B , Tornari C , Slack A , Murphy P , Ahmed I , Burnay V , Karagama Y
Published: May 2021

Introduction

The COVID-19 pandemic has placed exceptional demands on Intensive Care Units (ICU) across the world – particularly requiring patients to be intubated and mechanically ventilated. Laryngeal injury following intubation is a common occurrence, therefore this study aims to analyse airway, voice, and swallow (AVS) outcomes of patients intubated for COVID-19 pneumonitis and compares it to intubated non-COVID-19 respiratory patients and other ICU admissions.

Method

We collected data from inpatient records, and follow-up clinics on intubated adult patients discharged from a tertiary care hospital ICU between 01/03/20 and 30/04/20. Patients were assessed with the AVS Scale, Voice Handicap Index-10 (VHI-10), and Eating Assessment Tool-10 (EAT-10).

Results

86 patients were admitted with COVID-19 pneumonitis, 17 patients were admitted with non-COVID-19 respiratory failure, and 26 patients were admitted with a non-respiratory diagnosis.

The COVID-19 cohort demonstrated higher rates of AVS difficulties (airway 59% vs 44% and 31%, voice 40% vs 19% and 19%, swallow 21% vs 6% and 12%). VHI-10 and EAT-10 scores showed no significant differences between groups.

Conclusions

Patients intubated for COVID-19 pneumonitis reported higher rates of AVS difficulties against non-COVID-19 reasons for intubation. Robust prospective screening protocols are essential to improving patient outcomes by highlighting and therefore managing laryngological sequelae that occur following intubation.
266 Mini C-Arm Use in The Emergency Department for Fracture Management During The COVID-19 Pandemic: A Pilot Study in A Tertiary Paediatric Referral Centre
Authors: Rammohun A , Studnicka K , Talbot C
Published: May 2021

Introduction

We introduced the use of a Mini C-arm in managing distal limb fractures to minimise admissions and patient flow within the hospital.

Method

Prospective data collected between April and June 2020. Treatment details and imaging obtained from patient notes and PACS. A matching group from 2019 analysed for comparison.

Results

Mini c-arm was used for manipulation of closed fractures of forearm (9), tibia (2), distal humerus (1), and foreign body removal (1). 11 procedures performed in ED with intranasal diamorphine and Entonox (5), intravenous Ketamine (5), or local anaesthetic (1), two in fracture clinic under Entonox. Fracture position was on average 7° from the anatomical. 1 Distal humerus required surgical correction. 1 admission after sedation. In the control group, 8 patients underwent manipulation under GA (4 ORIFs) and 2 procedures were done under sedation in ED. All patients were admitted. The quality of reduction varied on average 4º from anatomical. No patients required repeated procedures and all were followed up in a face to the face fracture clinic.

Conclusions

Reduced admission rate, need for GA and flow to RD without an obvious reduction in the quality of manipulation resulted from both mini c-arm use and good cooperation with ED facilitating the sedation.
341 The Diagnosis and Management of Appendicitis During the COVID-19 Pandemic: The Pennine Acute Trust Experience
Authors: Idama D , Aldersley G , Connolly M , O'Connor A
Published: May 2021

Introduction

Appendicitis management has evolved recently with more reliance on Computed Topography (CT) and laparoscopic surgery being commonplace. In this project we looked at how the Coronavirus pandemic (COVID-19) had impacted the diagnosis, management and outcomes of patients with appendicitis in our unit.

Method

A retrospective review of patients diagnosed with appendicitis from 1st March – 30th April in 2019 and 2020. Data was collected on diagnosis, management and outcomes.

Results

In 2020, 91 patients were identified (mean 33, range 6-85, F:M 1:1.4). In 2019, 107 patients were identified (mean 32, range 7-69, M:F 1:1.1). There was no significant difference in patients’ symptom duration (p = 0.21), White Cell Count (p = 0.20) or C-Reactive Protein (p = 0.10). More CTs were performed in 2020 (56/91, 61.5%) than in 2019 (40/107, 37.4%). Less patients underwent appendicectomy in 2020 (75/91, 82.4%) than in 2019 (104/107, 97.2%). Open appendicectomies were performed in 64% (48/75) of those operated in 2020 compared with 12.2% (13/104) in 2019. There was no difference in hospital length of stay or re-admissions rates.

Conclusions

The diagnosis and management of appendicitis changed considerably at our trust during COVID-19 with more reliance on CT diagnosis and less use of laparoscopy. Despite this, outcomes remained unchanged.
555 The Unintended Consequences Of COVID-19 on the Quality of Documentation of Operation-Notes
Authors: Camilleri-Brennan J , Lim M
Published: May 2021

Introduction

Operation-notes are crucial as they impact on the care of patients post-operatively. During COVID-19, a sizeable proportion of General Surgical procedures were performed at a local “cold” site private hospital. This study aims to determine the direct impact of COVID-19 on the standard of operation-note documentation at a non-routine site compared to our routine site.

Method

The Royal College of Surgeons Good Surgical Practice guidance highlights 19 key-variables to record within operation-notes. 300 consecutive operations were identified between May and August 2020 and details of electronic operation-notes collected. Throughout this study period, educational emails and posters were introduced at both sites secondary to ongoing audit.

Results

228/300 (76%) operations took place at our main hospital. The remainder were commissioned to the other. Operating surgeons and anaesthetists were similar at both sites. Quality of documentation was poorer for many key variables at the cold site when compared with the main site (operating-surgeons (22% vs 91%), urgency of operation (62% vs 99%), antibiotic prophylaxis (72% vs 99%) and DVT prophylaxis (21% vs 98%)).

Conclusions

COVID-19 has resulted in many unintended consequences including a reduction in the quality of operation-notes. Moving forward, this may be reduced by improving information technology resources and increasing awareness and education.
749 Delivering Safe and Timely Cancer Care During COVID 19. Lessons and Successes from The Transition Period
Authors: Dirie J , Hart E , Mahesan T , Fawcett W , Perry M , Janardanan S , Moschonas D , Krishnaji P , Chedid W A
Published: May 2021

Introduction

Delivering timely cancer care during the COVID-19 pandemic was a major challenge. We analysed our success in addressing this.

Method

A key factor was the proximity of a private hospital (GN) to the primary trust. GN acted as a ‘clean site’. From 6th April 2020, two robots and dedicated staff were relocated to day surgery theatres with direct access to GN. Procedures and post-operative recovery happened in GN. National surgical guidelines were followed related to Covid-19. All theatre staff were swabbed weekly. Patients were risk stratified prior to admittance.

Results

We reviewed operations performed and cancer pathway data from March to June 2020 and compared it to data collected from August to November 2019. From March until June 2020 we performed 369 cancer operations; 120 robotic, 138 endoscopic and 7 open cases. From August to November 2019 we performed 407 cancer operations; 116 robotic, 175 endoscopic and 7 open cases. No elective patient developed symptomatic COVID-19 secondary to admission.

Conclusions

This study demonstrates that with rapid development of separate ‘clean’ and ‘COVID’ sites, we successfully delivered a comparable, safe and effective cancer service. As we potentially face a second wave we share our success to see if these changes can be replicated elsewhere.
764 Human Factors in Operative Theatres During the Covid-19 Pandemic: A Cross-sectional Analysis of Operating Theatre Staff Experiences in a Regional Centre
Authors: Murchison L E , Anbarasan R , Mathur A , Kulkarni M
Published: May 2021

Introduction

In the already high-risk, high-stress environment of the operating theatre, operating during Covid-19 has brought its own unique challenges. Communication, teamwork and anxiety related new operating practices secondary to Covid-19 are hypothesised to have a negative impact on patient care.

Method

We conducted a single-centre online survey of operating theatre staff from 22nd June–6th July 2020. Respondents completed 18 human factors questions related to COVID-19 precautions including communication, teamwork, situational awareness, decision making, stress, fatigue, work environment and organisational culture. Questions consisted of yes/no responses, multiple choice and Likert items. Kruskall-Wallis tests, Chi-Squared, Mann Whitney U tests, Spearman’s correlation coefficient, lambda and Cramer’s V tests were used. Free-text responses were also reviewed.

Results

116 theatre staff responded. Visual (90.5%), hearing/ understanding (96.6%) difficulties, feeling faint/lightheaded (66.4%) and stress (47.8%) were reported. Decreased situational awareness was reported by 71.5% and correlated with visors (r = 0.27 and p = 0.03) and FFP2/3 mask usage (r = 0.29 and p = 0.01). Reduced efficiency of theatre teams was reported by 75% of respondents and 21.5% felt patient safety was at greater risk due to Covid-19 precautions in theatre.

Conclusions

Organisational adjustments are required, and research focused on development of fit-for-purpose personal protective equipment (PPE).
829 Is There an Ongoing Role For 'Telephone Triage Clinics' Post COVID-19?
Authors: Holmes B , Mirza U , Manning C , Cooke R , Jugdey R
Published: May 2021

Introduction

COVID-19 has placed unprecedented demand on services at ELHT and it has become necessary to have telephone clinics to reduce the number of face-to-face clinics. A ‘telephone triage clinic’ was set up for referrals from A&E. Our project evaluated patient and clinician satisfaction on this.

Method

We carried out a retrospective telephone questionnaire with patients over a one-week period during the pandemic. We focussed on overall satisfaction of the consultation and quality of communication. Consultants were also surveyed for their opinion on the clinics.

Results

From 30 patients, 77% said they were ‘very satisfied’ with the overall experience. 80% of patients were ‘very satisfied’ with the overall length of the telephone consultation. 50% of patients felt the clinician was only ‘adequately’ able to assess them over the telephone. The consultants were less satisfied with the overall experience of telephone consultation. A common theme was that they felt ED documentation could be improved to help inform ongoing management.

Conclusions

Overall, patients were satisfied with the consultations. It has been successful in minimising face to face consultations however some presentations necessitate further evaluation. We need to identify those injuries appropriate for virtual follow up and design a local protocol for these.
941 Post-Operative Outcomes of Patients Undergoing Surgery During the Acceleration Period of COVID-19 Infection
Authors: Fifer H , Coe P , Geogloman I , Qaiser R , Saleh A , Adair R , Peter M , Dobbins B , Saha A
Published: May 2021

Introduction

There are concerns around the safety of performing surgery during COVID-19 outbreaks with few sources of robust evidence.

Method

We analysed 5020 consecutive patients who underwent surgery during the acceleration phase of COVID-19 at our hospital from 31st January to 13th April 2020. Data were also analysed for all patients who had a COVID-19 positive test result during the same study period.

Results

156 patients (3%) developed COVID-19 symptoms after surgery; 28 patients (<1%) subsequently had a positive swab result. All-cause mortality was 44 patients (0.9%); 33 deaths (75%) were due to non COVID-19 diagnoses. There were no adverse COVID-19 related outcomes in any of the 648 patients who had cancer operations. Of 28 COVID-19 positive patients, 11 died (8 orthopaedic, 2 urology, 1 vascular surgery) of which 10 had an emergency admission; all were over 70 years of age. Recent surgery was not an independent prognostic factor for survival after COVID-19 infection. 12% of positive COVID-19 swabs were from long-stay patients.

Conclusions

Of 5020 operative patients, 0.2% died from COVID-19 and most complications were not related to the infection. With careful consideration, surgery can be provided safely during times of COVID-19 outbreaks with particular emphasis on avoiding in-hospital transmission.
956 Patient Satisfaction of Teleconsultation in Plastic Surgery During the COVID-19 Pandemic
Authors: Rafii M , Freethy A , Chan J
Published: May 2021

Introduction

The COVID-19 pandemic has witnessed an increased reliance on telemedicine. Patient satisfaction is a key indicator of whether telephone consultations deliver high-quality care. This study evaluates patient perceptions of telephone consultations conducted in a single plastic surgery outpatient department.

Method

Structured telephone interviews using an adapted Telehealth Usability Questionnaire and the NHS Friends and Family Test were conducted in 98 patients who had undergone outpatient telephone consultations with a plastic surgeon. 13 questions explored domains of usefulness, interaction quality, reliability, patient satisfaction, and future use of telehealth.

Results

72 of 98 (73%) completed the survey. Male(49):Female(23). Mean age 59 (range 17-91). 50.4% Strongly agreed (SA) and 24.3% agreed (A) to questions addressing usefulness of the platform. For interaction quality; 63% SA and 21% A. 47% disagreed with questions pertaining to reliability.

Overall, 75% were either SA/A for satisfaction and 81% would use telehealth again. No significant difference was found in domain scores when comparing sex or age groups.

Conclusions

Overall, patient perceptions were positive towards the usefulness and interaction quality of telephone consultations. However, reliability scored poorly. Most patients were satisfied with the care provided. Comparison to other telehealth mediums e.g. video consultation and patient safety studies are needed.
981 Management of Epistaxis During The COVID-19 Pandemic Our Experience
Authors: Eastwood M , Metcalfe C , Lovett A , Isles M
Published: May 2021

Introduction

Epistaxis is a frequently encountered emergency by ENT services. With the COVID-19 outbreak, examination and procedures on the upper airway may put otolaryngologists at increased risk of infection. ENT UK released new guidance for the management of epistaxis during COVID-19 pandemic to safely manage epistaxis and reduce admissions. We report our experience in managing epistaxis using a locally approved protocol using this guidance.

Method

Prospective audit of management and outcomes of patients presenting to acute ENT services at a large teaching hospital with epistaxis over a 3-month period.

Results

58 patients attended with epistaxis. Various management strategies were used with 50% managed with non-absorbable packing. 15 cases required admission only 8 solely due to epistaxis. Only 5 cases (8.6%) reported re-bleeding within 30 days with one case (1.7%) requiring readmission.

Conclusions

The current guidance appears to be a safe and effective method for managing epistaxis and minimising the number of admissions which may lead to a permanent shift in epistaxis management.