bluuebunny/crossref_metadata_2025_split huggingface dataset:
1013 Preoperative Nasopharyngeal Swab Testing and Postoperative Pulmonary Complications in Patients Undergoing Elective Surgery During The SARS-Cov-2 Pandemic
Authors:   COVIDSurg Collaborative
Published: May 2021

Abstract

Introduction
This study aimed to evaluate the association between preoperative SARS-CoV-2 testing and postoperative pulmonary complications in patients undergoing elective cancer surgery.

Method
International cohort study including adult patients undergoing elective surgery for cancer in areas affected by SARS-CoV-2 up to 19 April 2020 (NCT04384926). Patients suspected preoperatively of SARS-CoV-2 infection were excluded. The primary outcome measure was postoperative pulmonary complications at 30 days after surgery.

Results
Of 8784 patients (432 hospitals, 53 countries), 2303 patients (26.2%) underwent preoperative testing: 1458 (16.6%) had a swab test, 521 (5.9%) CT only, and 324 (3.7%) swab and CT. The overall pulmonary complication rate was 3.9% and SARS-CoV-2 infection rate was 2.6%. After risk adjustment, only a nasopharyngeal swab test (adjusted odds ratio 0.68, 95% confidence interval 0.68-0.98, p = 0.040) was associated with lower rates of pulmonary complications. Swab testing remained beneficial before major surgery and in high SARS-CoV-2 population risk areas but not before minor surgery in low incidence areas.

Conclusions
Preoperative nasopharyngeal swab testing was beneficial before major surgery and in high SARS-CoV-2 incidence areas. There was no proven benefit of swab testing before minor surgery in low incidence areas.
35 Comparative Performance of Prediction Model, Non-Expert and Tele-Diagnosis of Common External and Middle Ear Disease Using A Patient Cohort from Cambodia That Included One Hundred and Thirty-Eight Ears
Authors: Schuster-Bruce J , Shetty P , O'Donovan J , Mandavia R , Sokdavy T , Bhutta M 
Published: May 2021

Abstract

Introduction
Globally 6% of the population suffers from disabling hearing loss and the majority resides in low- and middle-income countries, but diagnosis and treatment are hampered by poor availability of expert diagnosis. We compared the utility of tele-diagnosis, non-expert diagnosis, and prediction model diagnosis as a screening tool for common external and middle ear disorders.

Method
We recruited consecutive adult and paediatric patients presenting with ear or hearing symptoms to ENT outpatients at Children’s Surgical Centre, Cambodia. Each participant underwent sequential symptomatic and otoscopic assessment by a non-specialist and an ENT specialist. The non-specialist captured data using a novel automated symptom questionnaire loaded onto a smartphone otoscope. An ENT specialist in the UK subsequently reviewed these data.

Results
138 ears were recruited. The prediction model performed poorly, but absence of otorrhoea was found to reliably exclude a diagnosis of chronic suppurative otitis media (negative predictive value=0.99). Both on-site non-expert and expert tele-diagnosis had high diagnostic specificity (90-99% and 86-99%), but low sensitivity (&lt;43% and 32-100%).

Conclusions
We report the first study to directly compare approaches for non-specialist diagnosis of disorders of the middle/external ear, which shows suboptimal but comparable performance using an automated questionnaire, on site non-expert diagnosis, or remote expert diagnosis
182 Treating Distal Femur Fractures Without Fluoroscopy: Comparison of Implants Used in a Rural Hospital in Tanzania
Authors: Allen J , Kiewsa S 
Published: May 2021

Abstract

Introduction
SIGN is a charity providing implants for hospitals with limited resources. There are two nails that can be inserted without fluoroscopy - the standard SIGN nail and the Fin nail. We aimed to evaluate the effectiveness of these implants in treating distal femur fractures.

Method
Retrospective analysis of SIGN database at Nkoaranga Hospital, Tanzania between July 2017 and January 2019. 28 patients (20 male, 8 female) with distal femur fractures had a standard nail (n = 14) or a Fin nail (n = 14). Inclusion criteria: distal femur fractures treated with intramedullary nail. Exclusion criteria: age&lt;16, open injury, antegrade approach, no follow-up at 4 weeks.

Results
Mean age was 41.4 (18-81). Average time from injury to surgery was 29 days. Average first follow-up was 14 weeks (4-73). Painless weight-bearing was achieved in 93% (13/14) of standard nails and 100% (14/14) of Fin nails. Knee flexion &gt;30° was 64% (9/14) in standard nails and 50% (7/14) in Fin nails. Screw loosening was seen in 7% (1/14) in standard nails and no patients with Fin nails. There were no instances of implant breakage, clinical deformity, or infection.

Conclusions
Patients had variable follow-up and presented late causing delayed treatment. Both nails can achieve excellent results. A larger sample size is required.
203 Developing and Fine-Tuning Novel 3D-Printed Biodegradable Scaffolds to Promote Auricular Cartilaginous Regeneration for Surgical Implantation
Authors: Srivastava A , Long E , Wu L , Song W H 
Published: May 2021

Abstract

Introduction
Microtia, a congenital cartilaginous defect, poses major challenges in cosmetic surgery. Biodegradable polymers promote chondrogenesis, with promises of seeding cells into synthetic-polymer-implants for surgical fixation. However, existing polymers used in auricular reconstruction present limitations including inflammation, fibrosis, and extrusion. This study aimed to modulate the mechanical properties of the novel polylactic-acid/polyhydroxyalkanoate (PLA/PHA) blend by 3D-printing and hence, evaluate its suitability to the auricular microenvironment in developing next-generation reconstructs.

Method
Digitally defined PLA/PHA scaffolds were free-form 3D-printed at various infill densities and thicknesses. Through tensile testing, tensile moduli, yield point, maximum strength, tensile toughness, and stiffness were calculated, alongside Finite Element Analysis (FEA) and contact angle tests. Finally, preliminary cell seeding was conducted.

Results
Increasing infill densities of PLA/PHA scaffolds from 30%-60% significantly increased tensile moduli, yield point and maximum strength (P &lt; 0.01). Tensile stiffness increased significantly with scaffold thicknesses between 1mm-2mm (P &lt; 0.05). Cell studies showed promising proliferative activity.

Conclusions
The mechanical properties and structural stiffness of 3D-printed PLA/PHA scaffolds can be significantly tailored by altering infill density and thickness, respectively. The digitally defined interconnected pores within printed PLA/PHA scaffolds reduce stiffness mismatches between surgical-synthetic polymers and auricular cartilage, potentially promoting cell migration and nutrition transportation in future reconstructs.
306 Anterior Cruciate Ligament Graft Rupture: Analysis of Anteromedial Versus Trans-Tibial Portal Technique for Femoral Tunnel Placement in 473 Patients
Authors: Al-Hourani K , Shepperd J , Sripathmanathan K , Zhang Y , Hull B , Murray I R , Duckworth A D , Keating J F , White T O 
Published: May 2021

Abstract

Introduction
Correct femoral tunnel position in anterior cruciate ligament reconstruction (ACLR) is critical in obtaining good clinical outcomes. We aimed to delineate whether any difference exists between the anteromedial and trans-tibial portal femoral tunnel placement techniques on the primary outcome of ACLR, graft rupture.

Method
Adult patients (&gt;18 years old) who underwent primary ACLR between January 2011 - January 2018 were identified and divided based on portal technique (anteromedial v trans-tibail). The primary outcome measure was graft rupture. Univariate analysis was used to delineate association between independent variables and outcome. Binary logistic regression was utilised to delineate odds ratios of significant variables.

Results
473 patients were analysed. Median age at surgery was 27 years old (range 18-70). 152/473 (32.1%) patients were anteromedial group compared to 321/473 (67.9%) trans-tibial. 25/473 (5.3%) patients sustained graft rupture. Median time to graft rupture was 12 months (IQR 9). A higher odd for graft rupture was associated with the anteromedial group, which trended towards significance (OR 2.03; 95% CI 0.90 - 4.56, p = 0.081).

Conclusions
There is no statistically significant difference in ACLR graft rupture rates when comparing anteromedial and trans-tibial portal technique for femoral tunnel placement. There was a trend towards higher rupture rates in the anteromedial portal group.
975 Outcome of Low Verus Standard Pressure Pneumoperitoneum in Laparoscopic Cholecystectomy: A Randomized Trial
Authors: Anwaar H , Ahmed R , Hashmi Z , Qavi Q , Zafar T 
Published: May 2021

Abstract

Introduction
Recent studies have shown that patients may experience considerable pain after laparoscopic cholecystectomy as well. Hence, this study was done to compare results on post op pain with low pressure pneumoperitoneum compared with standard pneumoperitoneum.

Method
100 patients were selected for study and equally divided in two groups randomized into Low pressure (n = 50) and Standard pressure (n = 50). Operative time (min), postoperative pain (VAS) and frequency of Shoulder Tip Pain was noted in both groups

Results
A total of 100 patients were enrolled for this study. Patients were divided into two groups i.e. Group-A (Standard pressure) and Group-B (Low pressure). In group-A, there were 35(70%) males and 15(30%) females, while in group-B, there were 41(82%) males and 9(18%) females. Mean age of group-A patients was 42.0±7.0 years and 44.5±8.1 years in group-B. In group-A, 18(36%) patients had shoulder tip pain, while 4(8%) patients had had shoulder tip pain in group-B patients with a p-value of 0.001, which is statistically significant.

Conclusions
Laparoscopic cholecystectomy using low pressure pneumoperitoneum is feasible and results in less post-operative shoulder tip pain.
1022 Socioeconomic Deprivation and Colorectal Cancer Survival
Authors: Ali F , Jha M 
Published: May 2021

Abstract

Background
Factors related to CRC survival include age, tumour site and stage. Other factors that may play a role on survival include race and socioeconomic status(SES).We aim to investigate the impact of SES on CRC survival.

Method
All patients diagnosed with CRC between January 2006-January 2019 were included. Demographics were collected from a prospective database. SES was defined using the Index of Multiple Deprivation(IMD).Cox-regression was used to investigate the effect of factors on survival and Kaplan-Meier to estimate survival.

Results
A total of 5,073 patients diagnosed with CRC with a median follow up of 65 months were include. Overall survival was 72.2% (76.0%0-78.4%), 59.6%(58.2%-61.0%) and 50.3% (48.8%-51.8%) at 1 year, 3 years and 5 years, respectively. Colon cancer was associated with worse survival(p = 0.00256,HR = 1.163). On multivariate analysis, socioeconomic deprivation was associated with poorer survival (HR = 1.02,p=0.00302).Male and female sex were associated with similar survival outcomes(HR = 0.9831 and 0.9341,respectively; p = 0.986 and 0.946 respectively).

Conclusions
SES impact on CRC survival seems to be inconsistent across the literature potentially due to lack of uniformity of indices used to assess SES and the heterogeneity of access to healthcare. This could ultimately impact comparability across different studies investigating the impact SES on CRC survival.
Control method for the stable operation of distributed inverters following the introduction of large-scale renewable energy to a remote island grid
Authors: Sato Shoichi , Noro Yasuhiro 
Published: May 2021

Abstract
The introduction of large-scale renewable energy requires a control system that can operate multiple distributed inverters in a stable way. This study proposes an inverter control method that uses information corresponding to the inertia of the synchronous generator to coordinate the operation of battery energy storage systems. Simulation results for a system with multiple inverters applying the control method are presented. Various faults such as line-to-line short circuits and three-phase line-to-ground faults were simulated. Two fault points with different characteristics were compared. The voltage, frequency and active power quickly returned to their steady-state values after the fault was eliminated. From the obtained simulation results, it was verified that our control method can be operated stably against various faults.
Performance analysis of a floating photovoltaic covering system in an Indian reservoir
Authors: Ravichandran Nagananthini , Ravichandran Nagavinothini , Panneerselvam Balamurugan 
Published: May 2021

Abstract
Floating photovoltaic (FPV) systems are one of the globally emerging technologies of renewable energy production that tend to balance the water–energy demand by effectively saving the evaporated water from reservoirs while generating electrical power. This study presents the performance analysis of a model FPV plant in an Indian reservoir. The Mettur dam reservoir located in Tamil Nadu, India with a hydroelectric power plant of 150-MW capacity is considered as a test case. The preliminary design of the FPV plant is proposed based on a detailed study of the key design elements and their suitability for Indian reservoirs. The proposed plant is numerically analysed for various tilt angles, mounting systems and tracking mechanisms in order to assess its potential power generation. A flat-mount system in landscape orientation was found to exhibit a high performance ratio. Further, a fixed-tilt FPV system with a panel slope of 10° and an FPV system with single-axis tracking were found to be suitable for the Mettur reservoir. Further, cost analysis of the FPV system is also presented along with the carbon-footprint estimation to establish the economic and environmental benefits of the system. The results show that the total potential CO2 saving by a FPV system with tracking is 135 918.87 t CO2 and it is 12.5% higher than that of a fixed-mount FPV system.
The spread of COVID-19 and the BCG vaccine: A natural experiment in reunified Germany
Authors: Bluhm Richard , Pinkovskiy Maxim 
Published: May 2021

Summary
The ‘BCG hypothesis' suggests that the Bacillus Calmette-Guérin (BCG) vaccine against tuberculosis limits the severity of COVID-19. We exploit the differential vaccination practices of East Germany and West Germany prior to reunification to test this hypothesis. Using a difference in regression discontinuities (RD-DD) design centred on the end of universal vaccination in the West, we find that differences in COVID-19 severity across cohorts in the East and West are insignificant or have the wrong sign. We document a sharp cross-sectional discontinuity in the severity of the disease, which we attribute to limited mobility across the long-gone border and which disappears when we control for social connectedness. Case and death data after the end of the first lockdown on 26 April does not display a discontinuity at the former border, suggesting that mobility (as opposed to BCG vaccination) played a major role during the initial outbreak.
Identification in simple binary outcome panel data models
Authors: Honoré Bo E , de Paula Áureo 
Published: May 2021

SummaryThis paper first reviews some of the approaches that have been taken to estimate the common parameters of binary outcome models with fixed effects. We limit attention to situations in which the researcher has access to a data set with a large number of units (individuals or companies, for example) observed over a number of time periods. We then apply some of the existing approaches to study fixed-effects panel data versions of entry games, like the ones studied in Bresnahan and Reiss (1991) and Tamer (2003).
Case report: multimodality imaging to diagnose cardiac diffuse large B-cell lymphoma
Authors: Alansari Yahya E , Yudhistiara Brian , Michel René P , Elstein Eleanor 
Published: May 2021

Abstract

Background
Primary cardiac lymphoma (PCL) is rare and can present with a wide variety of clinical symptoms, frequently leading to a delay in diagnosis.

Case summary
We report a case of a PCL in an 81-year-old man. Cardiac magnetic resonance imaging showed multiple masses in the right atrium and a mass in the right ventricular outflow tract extending to the pulmonary artery. Biopsy revealed a diffuse large B-cell lymphoma. The patient also had metastases to the liver and lung on the positron emission tomography–computed tomography (PET–CT) scan. He was treated with R-CHOP chemotherapy, with complete remission documented PET–CT scans.

Conclusion
Although most patients with PCL die before chemotherapy can be initiated, a timely diagnosis can result in a favourable outcome.
Uncertainty estimation for deep learning-based automated analysis of 12-lead electrocardiograms
Authors: Vranken Jeroen F , van de Leur Rutger R , Gupta Deepak K , Juarez Orozco Luis E , Hassink Rutger J , van der Harst Pim , Doevendans Pieter A , Gulshad Sadaf , van Es René 
Published: May 2021

Abstract

Aims
Automated interpretation of electrocardiograms (ECGs) using deep neural networks (DNNs) has gained much attention recently. While the initial results have been encouraging, limited attention has been paid to whether such results can be trusted, which is paramount for their clinical implementation. This study aims to systematically investigate uncertainty estimation techniques for automated classification of ECGs using DNNs and to gain insight into its utility through a clinical simulation.

Methods and results
On a total of 526 656 ECGs from three different datasets, six different methods for estimation of aleatoric and epistemic uncertainty were systematically investigated. The methods were evaluated based on ranking, calibration, and robustness against out-of-distribution data. Furthermore, a clinical simulation was performed where increasing uncertainty thresholds were applied to achieve a clinically acceptable performance. Finally, the correspondence between the uncertainty of ECGs and the lack of interpretational agreement between cardiologists was estimated. Results demonstrated the largest benefit when modelling both epistemic and aleatoric uncertainty. Notably, the combination of variational inference with Bayesian decomposition and ensemble with auxiliary output outperformed the other methods. The clinical simulation showed that the accuracy of the algorithm increased as uncertain predictions were referred to the physician. Moreover, high uncertainty in DNN-based ECG classification strongly corresponded with a lower diagnostic agreement in cardiologist’s interpretation (P &lt; 0.001).

Conclusion
Uncertainty estimation is warranted in automated DNN-based ECG classification and its accurate estimation enables intermediate quality control in the clinical implementation of deep learning. This is an important step towards the clinical applicability of automated ECG diagnosis using DNNs.
Effectiveness of genomic selection for improving provitamin A carotenoid content and associated traits in cassava
Authors: Esuma Williams , Ozimati Alfred , Kulakow Peter , Gore Michael A , Wolfe Marnin D , Nuwamanya Ephraim , Egesi Chiedozie , Kawuki Robert S 
Published: May 2021

Abstract
Global efforts are underway to develop cassava with enhanced levels of provitamin A carotenoids to sustainably meet increasing demands for food and nutrition where the crop is a major staple. Herein, we tested the effectiveness of genomic selection (GS) for rapid improvement of cassava for total carotenoids content and associated traits. We evaluated 632 clones from Uganda’s provitamin A cassava breeding pipeline and 648 West African introductions. At harvest, each clone was assessed for level of total carotenoids, dry matter content, and resistance to cassava brown streak disease (CBSD). All clones were genotyped with diversity array technology and imputed to a set of 23,431 single nucleotide polymorphic markers. We assessed predictive ability of four genomic prediction methods in scenarios of cross-validation, across population prediction, and inclusion of quantitative trait loci markers. Cross-validations produced the highest mean prediction ability for total carotenoids content (0.52) and the lowest for CBSD resistance (0.20), with G-BLUP outperforming other models tested. Across population, predictions showed low ability of Ugandan population to predict the performance of West African clones, with the highest predictive ability recorded for total carotenoids content (0.34) and the lowest for CBSD resistance (0.12) using G-BLUP. By incorporating chromosome 1 markers associated with carotenoids content as independent kernel in the G-BLUP model of a cross-validation scenario, prediction ability slightly improved from 0.52 to 0.58. These results reinforce ongoing efforts aimed at integrating GS into cassava breeding and demonstrate the utility of this tool for rapid genetic improvement.
Generation of Drosophila attP containing cell lines using CRISPR-Cas9
Authors: Mariyappa Daniel , Luhur Arthur , Overton Danielle , Zelhof Andrew C 
Published: May 2021

Abstract
The generation of Drosophila stable cell lines has become invaluable for complementing in vivo experiments and as tools for genetic screens. Recent advances utilizing attP/PhiC31 integrase system has permitted the creation of Drosophila cells in which recombination mediated cassette exchange (RMCE) can be utilized to generate stably integrated transgenic cell lines that contain a single copy of the transgene at the desired locus. Current techniques, besides being laborious and introducing extraneous elements, are limited to a handful of cell lines of embryonic origin. Nonetheless, with well over 100 Drosophila cell lines available, including an ever-increasing number CRISPR/Cas9 modified cell lines, a more universal methodology is needed to generate a stably integrated transgenic line from any one of the available Drosophila melanogaster cell lines. Here, we describe a toolkit and procedure that combines CRISPR/Cas9 and theaaa PhiC31 integrase system. We have generated and isolated single cell clones containing an Actin5C::dsRed cassette flanked by attP sites into the genome of Kc167 and S2R+ cell lines that mimic the in vivo attP sites located at 25C6 and 99F8 of the Drosophila genome. Furthermore, we tested the functionality of the attP docking sites utilizing two independent GFP expressing constructs flanked by attB sites that permit RMCE and therefore the insertion of any DNA of interest. Lastly, to demonstrate the universality of our methodology and existing constructs, we have successfully integrated the Actin5C::dsRed cassette flanked by attP sites into two different CNS cell lines, ML-DmBG2-c2 and ML-DmBG3-c2. Overall, the reagents and methodology reported here permit the efficient generation of stable transgenic cassettes with minimal change in the cellular genomes in existing D. melanogaster cell lines.