bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrasonic Properties of Zinc-Lithium Phosphate Glass: Effect of Strontium
Authors: Nur Fatihah N. , Nurhafizah H. , Ahmad N.H.
Published: April 2021

Glasses of the general formula (50-x)P2O5 - 30ZnO - 20Li2O - (x)SrCO3, where (0.00 ≤ x ≤ 5.00 mol%) were prepared via the melt-quench technique. The mechanical properties of the glass are utilized by using ultrasonic testing. The absence of distinct and Bragg peaks in XRD spectra, confirming the amorphous nature of samples. The glass densities are found increases as well as the packing densities with respect to SrCO3 concentration, which leading to the decrease in molar volume values, indicating the rigidity of the glasses. The ultrasonic results and other measured parameters attribute to the Sr ion increase in the cross-link density by the formation of P-O-Sr due to the value of Poisson’s ratio obtained are between range of 0.1 to 0.2.
Fabrication and characterization of hydroxyapatite based cow bone polysulfone mixed matrix membrane
Authors: Nor Suhaida Rasman Siti , Riduan Jamalludin Mohd , Najieha Kamarudin Suraya , Khadijah Hubadillah Siti , Arif Budiman Pauzan Mohammad , Hafiz Dzarfan Othman Mohd
Published: April 2021

In this work, polysulfone (PSf)/hydroxyapatite (HAp) mixed matrix membrane were prepared were prepared by using phase inversion technique for ultrafiltration application. The prepared PSf/HAp mixed matrix membrane were characterized in term of morphological and physicochemical properties by using SEM, contact angle measurement, membrane tensile measurement and membrane porosity. Meanwhile the performance of PSf/HAp mixed matrix membrane was conducted in term of pure water flux (PWF) by using permeability machine. The surface morphology of the MMMs showed the increasing pore number and size as the concentration of HAp increase. The increment weight ratio of the HAp in PSf membrane enhanced the membrane water flux from 113.44 L/m2.h.bar to 228.13 L/m2.h.bar due to increased porosity of the membrane. Meanwhile, the strength of the membrane was increased from 3.82 MPa to 5.2 MPa as HAp increases from 0 to 1.0 wt.% and decreased to 2.49 MPa at 1.5 wt.% HAp. This study suggested that HAp is a promising candidate as additive that can improve PSf membrane performance.
Removal of direct red dye using polysulfone-chitosan ultrafiltration membrane
Authors: Hamdan J , Sabri N S M , Hasbullah H , Sokri M N M , Rahman S A , Kadirkhan F
Published: April 2021

Textile industries are one of the largest pollution contributor to the environment through high amount of wastewater discharge that contain high concentration dyes. The present state of application of using membrane technology in the removal of dyes from textile wastewater has shown positive pathway for this research. Chitosan are biopolymer that are naturally occurring. It is used as a hydrophilic additive in the fabrication of polysulfone (PSF) and chitosan (CS) membrane. Different loadings of CS at 0.1, 0.3, 0.5, 0.7 and 1.0wt% were used. The fabricated PSF-CS membrane by phase inversion method were characterized using SEM for its morphology, FTIR for its functional group and contact angle for membrane hydrophilicity. As the addition of CS increase the hydrophilicity of the PSF-CS membrane, excessive CS precipitation was observed at chitosan loading at 1.0wt% creating a large macro void causing lower permeation performance. It is found that PSF-CS membrane with 0.7wt% has the best contact angle and dye rejection performance of 65.49º and 99.78%.
Synthesis of graphene oxide via electrochemical process: A short review towards flexible synthesis method
Authors: Edward I I , Abdul Manaf N , Tahir Abdul Muthalib S A , Musram Rakunman M R , Tan L.S. , Tsuji T
Published: April 2021

Graphene-based material for instance graphene oxide (GO) and reduce graphene oxide (rGO) emerge as unique frontier material that have been widely applied in various application such as energy conversion, nanotechnology as well as oil and gas industry. It properties such as high mechanical properties and enhance electrical conductor have made this material outperforms existing frontier material thus features large-scale commercialization opportunity. At present, electrochemical method has attracted much attention in synthesizing graphene-based material (GO/rGO) due to its green technology (environmentally friendly process), low cost and enhanced efficiency. Nevertheless, based on contemporary studies, different demand in GO/rGO quality requires different parametric setup and characterization analyses subsequently provides significant challenge to identify a standard design of electrochemical that can produce various quality of GO/rGO. This inflexibility affects the progress of commercial scale-up thus entails a systematic review related to various aspects of electrochemical studies for instance parametric analysis, product/material characterization and applications. A parametric analysis includes electrolyte concentration, type of electrolyte, temperature, synthesis time, cathode and anode materials and voltage demand. While, for product characterization, several methods are evaluated for instance Transmission electron microscopy (TEM) and Raman spectroscopy (RAMAN). This review paper is beneficial to the researcher and industries as a rapid guideline towards the flexible mass-production of GO/rGO via electrochemical method. Finally, future research should be conducted on the flexible design of unit operation (i.e. reactor) to ensure process feasibility.
An insight into advance self-healing composites
Authors: Kadam Shankar , Chavan Sachin , Kanu Nand Jee
Published: April 2021

The purpose of the investigation is to review self-healing mechanisms and various advanced self-healing materials which are recently used for repairing composite materials. The manufacturing and characterization processes are studied in depth for self-healing carbon fiber reinforced composites, microcapsules, and supra-molecular elastomers. The composite structures fail due to internal cracks. These cracks are initiated due to continuous loading of structures. It is not possible to fill those cracks especially when the structures are at remote locations. Self-healing materials are designed and prepared to heal their cracks. The present review is about self-healing materials used for the fabrication of composites. It is expected that future applications are based on such advanced self-healing composite materials and thus it is needed to review advanced self-healing composite structures. A brief review of self-healing techniques and materials as well as applications are discussed in the present investigation. The efficient and effective manufacturing techniques are suggested through the article.
Deuterium permeability of a novel AlCrTaTiZr high entropy alloy coating
Authors: Zhang Wei , Wang Long , Luo Xiaofang , Gong Baoping , Wang Xiaoyu , Yang Jijun , Feng Yongjin
Published: April 2021

AlCrTaTiZr, AlCrTaTiZr nitride, and AlCrTaTiZr oxide coatings as tritium permeation barriers (TPBs) were prepared by magnetron co-sputtering technology on a CLF-1 (RAFM) substrate, to evaluate their hydrogen/deuterium permeation resistance. X-ray diffraction (XRD) analysis showed that the as-deposited coatings were amorphous. Scanning electron microscopy (SEM) results revealed that the deposition rates of the AlCrTaTiZr coating, AlCrTaTiZr nitride coating and AlCrTaTiZr oxide coating were approximately 2 μm h−1, 0.75 μm h−1 and 0.15 μm h−1, respectively. The properties of these high-entropy alloy (HEA) coatings were studied with electrochemical hydrogen (ECH) permeation test equipment and a high-temperature gas-driven deuterium permeation (GDP) device. The AlCrTaTiZr HEA coating had the best hydrogen permeation resistance during the electrochemical hydrogen permeation test. However, the AlCrTaTiZr nitride coating had the best deuterium permeation resistance during the gas-deuterium permeation test. Annealing experiments of these coatings showed that changes in their microstructures during the gas-driven deuterium permeation test were the main reasons for the different permeabilities of these coatings during the heating and cooling processes. The oxidization of the HEA coating during the deuterium permeation experiment may have been the main reason that the HEA coating showed better deuterium permeation resistance than the HEA oxide coating.
Intrinsically disordered proteins at the nano-scale
Authors: Ehm T , Shinar H , Meir S , Sekhon A , Sethi V , Morgan I L , Rahamim G , Saleh O A , Beck R
Published: April 2021

The human proteome is enriched in proteins that do not fold into a stable 3D structure. These intrinsically disordered proteins (IDPs) spontaneously fluctuate between a large number of configurations in their native form. Remarkably, the disorder does not lead to dysfunction as with denatured folded proteins. In fact, unlike denatured proteins, recent evidence strongly suggests that multiple biological functions stem from such structural plasticity. Here, focusing on the nanometer length-scale, we review the latest advances in IDP research and discuss some of the future directions in this highly promising field.
On the derivation of exact eigenstates of the generalized squeezing operator
Authors: Pereverzev Andrey , Bittner Eric R
Published: April 2021

We construct the states that are invariant under the action of the generalized squeezing operator

exp
(

za

†
k

−

z

*

a

k

)

for arbitrary positive integer k. The states are given explicitly in the number representation. We find that for a given value of k there are k such states. We show that the states behave as n
−k/4 when occupation number n → ∞ . This implies that for any k ≥ 3 the states are normalizable. For a given k, the expectation values of operators of the form

a

†

a

j

are finite for positive integer j < (k/2 − 1) but diverge for integer j ≥ (k/2 − 1). For k = 3 we also give an explicit form of these states in the momentum representation in terms of Bessel functions.
Defining a Safe Corridor of Cervical Branch Preservation in Lateral Platysmaplasty Surgery During Facial Rejuvenation Surgery
Authors: Malins William L E , Walker Hamish , Guirguis John , Riaz Muhammad , Saleh Daniel B
Published: April 2021

Background

During rhytidectomies, the cervical branch of the facial nerve (CBFN) can easily be encountered, and potentially injured, when releasing the cervical retaining ligaments in the lateral neck. This nerve has been shown to occasionally co-innervate the depressor anguli oris muscle, and damage to it can thus potentially compromise outcomes with a postoperative palsy.

Objectives

The authors sought to examine the lateral cervical anatomy specific to the CBFN to ascertain if the position of the nerve can be predicted, thereby enhancing safety of the platysmal flap separation and dissection from this lateral zone of adhesion.

Methods

Eleven cadaveric hemifaces were dissected, and the distance between the medial border of sternocleidomastoid muscle (SCM) and the CBFN was measured at 3 key points: (1) superior: the distance between the SCM and the nerve at the level of the angle of the mandible in neutral; (2) narrowest: the narrowest distance measurable between the superior and inferior points as the CBFN descends into the neck medial to the SCM; and (3) inferior: the distance at the most distal part of the cervical nerve identified before its final intramuscular course.

Results

The average distances (in mms) were as follows: superior = 12.1 (range, 10.1-15.4), narrowest = 8.8 (range, 5.6-12.2), and inferior = 10.9 (range, 7.9-16.7).

Conclusions

There is a narrow range between the nerve and the anterior border of SCM. We thus propose a safe corridor where lateral deep-plane dissection can be performed to offer cervical retaining ligament release, with reduced risk of endangering the CBFN.
COVID-19 biomarkers and their overlap with comorbidities in a disease biomarker data model
Authors: Gogate Nikhita , Lyman Daniel , Bell Amanda , Cauley Edmund , Crandall Keith A , Joseph Ashia , Kahsay Robel , Natale Darren A , Schriml Lynn M , Sen Sabyasach , Mazumder Raja
Published: April 2021

In response to the COVID-19 outbreak, scientists and medical researchers are capturing a wide range of host responses, symptoms and lingering postrecovery problems within the human population. These variable clinical manifestations suggest differences in influential factors, such as innate and adaptive host immunity, existing or underlying health conditions, comorbidities, genetics and other factors—compounding the complexity of COVID-19 pathobiology and potential biomarkers associated with the disease, as they become available. The heterogeneous data pose challenges for efficient extrapolation of information into clinical applications. We have curated 145 COVID-19 biomarkers by developing a novel cross-cutting disease biomarker data model that allows integration and evaluation of biomarkers in patients with comorbidities. Most biomarkers are related to the immune (SAA, TNF-∝ and IP-10) or coagulation (D-dimer, antithrombin and VWF) cascades, suggesting complex vascular pathobiology of the disease. Furthermore, we observe commonality with established cancer biomarkers (ACE2, IL-6, IL-4 and IL-2) as well as biomarkers for metabolic syndrome and diabetes (CRP, NLR and LDL). We explore these trends as we put forth a COVID-19 biomarker resource (https://data.oncomx.org/covid19) that will help researchers and diagnosticians alike.
O16: TARGETING THE LOX-1 SCAVENGER RECEPTOR ATTENUATES ATHEROSCLEROSIS AND NEOINTIMAL HYPERPLASIA IN APO-E NULL TRANSGENIC MICE
Authors: Cuthbert GA , Yuldasheva N , Tomlinson DC , Ponnambalam S , Homer-Vanniasinkam S
Published: April 2021

Introduction

The clinical consequences of atherosclerosis and post-procedure neointimal hyperplasia (NIH) represent a significant proportion of the vascular surgeon's workload. Lectin-like oxidized low density lipoprotein receptor-1 (LOX-1) is a class E scavenger receptor expressed in endothelial cells implicated in atherosclerosis and NIH. This study aims to demonstrate the therapeutic potential of LOX-1 targeting using a transgenic mouse model and LOX-1-specific non-antibody synthetic protein scaffolds called affimers.

Method

Apolipoprotein-E (APO-E) null and APO-E/LOX-1 double-null transgenic mice were fed a high cholesterol western diet for 12 weeks. One group of APO-E null mice was treated subcutaneously with LOX-1 affimer. All mice underwent unilateral common femoral artery wire injury at week 8. Mice were culled and tissues harvested for evaluation of atherosclerotic burden and femoral artery NIH. Studies were carried out with Home Office approval.

Result

Compared with APO-E null controls, carotid and femoral bifurcation atherosclerosis (p<0.05) and total aortic plaque coverage (p<0.01) were significantly reduced in APO-E/LOX-1 double-null mice. Reductions were observed in APO-E null mice treated with LOX-1 affimer, however these were non-significant. Femoral artery NIH was reduced by 16% in APO-E/LOX-1 double null and 11% in LOX-1 affimer treated APO-E null mice compared with untreated APO-E controls, however these reductions were non-significant.

Conclusion

This study demonstrates the therapeutic potential of LOX-1 targeting in large vessel atherosclerotic disease and NIH. Knockout of the LOX-1 transgene produced promising results, while results following LOX-1 affimer therapy were less impressive. Improvements in affimer pharmacokinetics and drug delivery optimisation are avenues for future studies.

Take-home message

The LOX-1 scavenger receptor is a potential novel therapeutic target in large-vessel atherosclerosis and neointimal hyperplasia.
O36: DEVELOPING A TRAUMA REGISTRY IN A MIDDLE INCOME COUNTRY – BOTSWANA
Authors: Joseph Motsumi Mpapho , Mashalla Yohana , Sebego Miriam , Ho-Foster Ari , Motshome Paul , Mokokwe Lebogang , Mmalane Mompati , Montshiwa Thapelo
Published: April 2021

Background

Botswana has a large burden of disease from injury, but no trauma registry. This study sought to design and pilot test a trauma registry at two hospitals.

Methods

A cross sectional study was piloted at a tertiary hospital and a secondary level hospital in Botswana. The study consisted of two stages: stage 1 mainly involved stakeholder consultations on existing data collection tools. Stage 2 consisted of two phases: Phase I involved retrospective collection of existing data from existing data collection tools and Phase II collected data prospectively using the proposed trauma registry prototype.

Results

The pre-hospital road traffic accident data is collected using hard copy forms and some of this data is transferred to a stand-alone electronic registry. The hospital phase of road traffic accident data all goes into hard copy files then stored in institutional registry departments. The post-hospital data is also partially stored as hard copies and some data is stored in a stand-alone electronic registry. The demographics, pre-hospital, triage, diagnosis, management and disposition had a high percent variable completion rate with no significant difference between phases I and II. However, the primary survey variables in Phase I had a low percent variable completion rate which was significantly different from the high completion rates in phase II at both hospitals. A similar picture was observed for the secondary survey at both hospitals.

Conclusion

Electronic trauma registries are feasible and data completion rate is high when using the electronic data registry as opposed to data collected using the existing paper-based data collection tools.

Keywords

Trauma registry, Injury registry, Road Traffic Accident Trauma Registry, Road Traffic Crushes Registry, Road Accident Registry.

SYSTEMATIC REVIEWS
O38: TACKING VERSUS NO TACKING IN LAPAROSCOPIC TOTALLY EXTRAPERITONEAL REPAIR OF PRIMARY INGUINAL HERNIA - A SYSTEMATIC REVIEW AND META-ANALYSIS
Authors: Horan J , M Sahebally S , Rogers A , Winter D
Published: April 2021

Introduction

The necessity of mesh fixation in laparoscopic totally extraperitoneal (TEP) inguinal hernia repair remains controversial. We performed a systematic review and meta-analysis to compare the effectiveness of mesh tacking versus no tacking in laparoscopic TEP repair for primary inguinal hernia.

Materials and Methods

PubMed, EMBASE and Cochrane databases were searched for relevant articles from inception until November 2019. All studies that compared tacking versus no tacking in TEP repairs for inguinal herniae were included. Recurrent and femoral herniae were excluded from the current analysis. The primary outcome measure was recurrence, while secondary outcomes included postoperative pain scores at discharge and at 1 month, mean operative time, length of stay and seroma rates. Random effects models were used to calculate pooled effect size estimates.

Result

Eight randomised controlled trials were included capturing 557 patients and 715 inguinal herniae. On random effects analysis, there were no significant differences between tacking and no tacking in terms of recurrence (OR 0.94, 95% CI=0.10 to 9.28, p=0.96), postoperative pain scores on discharge (Mean difference 0.82, 95% CI=-0.35 to 2.00, p=0.17) or at 1 month (Mean difference 0.53, 95% CI=-0.75 to 1.82, p=0.41), mean operative time (Mean difference 1.58 mins, 95% CI=-0.22 to 3.37, p=0.09), seroma (OR=0.70, 95% CI=0.28 to 1.74, p=0.44) or length of stay (Mean difference 0.11 days, 95% CI=-0.04 to 0.25, p=0.14).

Conclusion

Mesh tacking in laparoscopic TEP repair for primary inguinal herniae does not translate into improved postoperative outcomes and may be omitted.

Take-home message

Mesh tacking in laparoscopic TEP repair for primary inguinal herniae does not translate into improved postoperative outcomes and may be omitted.
P15: EVALUATING THE INTERNATIONAL USABILITY OF A LOW-COST LAPAROSCOPIC TRAINER IN LOW- AND HIGH-INCOME SETTINGS
Authors: Franco C , Sawhney R , Burke J , Aruparayil N , Chauhan M , Bolton W , Mishra A , Valdastri P , Jayne D
Published: April 2021

Introduction

Limited access to equipment and trained personnel restrict the adoption of laparoscopic surgery globally. There are a wide range of laparoscopic trainers available; however, most of these are not affordable. We propose an ultra-low-cost laparoscopic trainer (Lap-Pack), designed for portability, ease of assembly and compatibility with smart devices. The study aims to evaluate the usability of Lap-Pack as a training tool in low- and high-income settings.

Method

An international usability study was conducted in India and the UK in 2019. The participants (n=60), consisting of senior surgeons (n=18), junior trainees (n=20) and medical students (n=22), were asked to complete two tasks using Lap-Pack. Participants then scored Lap-Pack in a 25-point questionnaire, including a pre-established Face-Validity Criteria and four major evaluation categories – Usability, Camera, View, Material.

Result

Lap-Pack scored highly in Face-Validity with a combined mean score of 4.63 (95%CI: 4.31, 4.95, p <0.05) of a possible 6. In both cohorts, the Usability and Camera categories scored highest, with combined values respectively of 6.10 (95%CI: 6.01, 6.19, p <0.05) and 6.09 (95%CI: 5.88, 6.31, p <0.05) of a possible 7. For both centres, the highest-scoring individual criteria were its light weight and portability.

Conclusion

Overall, Lap-Pack was received positively by medical students and consultants alike, suggesting it is a suitable device for development of skills as part of a larger laparoscopic training curriculum. Its ease of assembly, portability and versatility show promise of increasing access to training opportunities worldwide.

Take-home message

Lap-Pack is an ultra-low-cost, portable laparoscopic simulator featuring compatibility with smart devices designed to help increase access to laparoscopic training worldwide. An international usability study found medical students, junior trainees and senior surgeons rated its usability and camera features highly, suggesting its employability as a laparoscopic training tool on a global scale.
P31: INTESTINAL GIP RELEASE MODIFICATIONS WOULD BE RELATED TO DUODENAL EXCLUSION: BARIATRIC SURGERY CONSEQUENCES
Authors: Pérez-Arana G , Almorza-Gomar D , Falckenheiner J , Camacho-Ramirez A , Bancalero-DelosReyes J , Prada-Oliveira JA
Published: April 2021

Introduction

The surgical techniques employed in the treatment of obesity discovered consequences on the global enterohomonal equilibrium. Many hypotheses focused on these enterohormonal system to explain the improvement of Type 2 Diabetes mellitus; as many other functional improvements. GIP is a hormone released for the duodenal and jejunal K cells, which had been implied in the glucose homeostasis. Our purpose was studied the changes in K cells populations, that could be related to the GIP serum level.

Method

We employed 16 non obese euglycemic male Wistar rats, randomised in the surgical groups. These groups were the surgical techniques (Sleeve gastric –SG-, Roux en Y Gastric Bypass –RYGB- and massive intestinal resection –IR50-), and two controls (fasting and Sham). After three months, rats were sacrificed. The intestinal portions (duodenum, jejunum and ileum) were resected and processed for the immunocytochemical technique.

Result

analysis showed several aspects. We found a significant increase of GIP K-cells (number GIP+/mm2 intestinal portion) in the duodenum of RYGB and RI50 versus both control groups. Other data showed a significant decrease of GIP K-cells in SG jejunum versus both control groups. Ileum did not significances.

Conclusion

GIP hormone was related to the nutrient flow through the intestine. Our data showed that GIP expression was inverse to the exclusion to this flow, as in RYGB technique. The increase was severe in IR50 too, which the duodenum was not affected. This mechanism revealed a complex physiologic mechanism, probably established by the feed-back with other hormones, as PPY.

Take-home message

The metabolic consequences after bariatric surgeries are related in enterohormones changes. The GIP release cellularity suffer changes according to the flow of nutrients.
P33: PROPOSAL OF A NEW SCORING TOOL FOR PREDICTION OF HYPOCALCEMIA IN PATIENTS UNDERGOING SURGERY FOR PAPILLARY THYROID CANCER
Authors: Ravindhran B , Rajan S , Mohan L N
Published: April 2021

Introduction

Post-operative hypocalcemia occurs more frequently in certain high-risk patients. The aim of our study is to propose a preliminary scoring system to identify patients who are more likely to develop hypocalcemia following surgery for papillary thyroid cancer.

Method

The study was performed with a retrospective developmental cohort(n=131) and a prospective validation cohort(n=71). Patients underwent either Total Thyroidectomy(TT), TT+Central Neck Dissection(CND) or TT+CND+Modified Radical Neck Dissection(MRND). Significant pre-operative variables and operative findings were converted into categorical variables for analysis. Univariate, multivariate analysis and a logistic regression were used to select significant predictors. The score was constructed by converting into integer, the regression coefficients of independently predictive factors in the logistic regression model. This score was validated prospectively in the validation cohort.

Result

24(18%) out of 131 patients in the developmental cohort and 16(22.5%) out of 71 patients in the validation cohort had symptomatic hypocalcemia. Thyroiditis, positive lymph node metastasis, central and lateral compartment dissection, Neutrophil-to-lymphocyte ratio(NLR)>3.35 and platelet-to-lymphocyte ratio(PLR)>135 were selected as significant predictors. A score with a range of 0-11 was created. The cut-off value for the score was 6 points(sensitivity of 92.0% and specificity of 89.0%). Areas under the ROC curve for the scores were 0.926 and 0.901 in the developmental and validation cohorts, respectively.

Conclusion

This score could be a tool in the prediction of hypocalcemia and could help in identifying patients at a higher risk of post-operative hypocalcemia and guide calcium/Vitamin D treatment, as well as facilitate a safe earlier hospital discharge for low risk patients.

Take-home message

The proposed scoring system could help in identification of patients at a higher risk of post-operative hypocalcemia.
Analysis of trimodal and bimodal therapy in a selective-surgery paradigm for locally advanced oesophageal squamous cell carcinoma
Authors: Zhou N , Mitchell K G , Corsini E M , Truong V T T , Antonoff M B , Mehran R J , Rajaram R , Rice D C , Roth J A , Sepesi B , Swisher S G , Vaporciyan A A , Walsh G L , Ajani J A , Hofstetter W L
Published: April 2021

Background

Long-term survival outcomes of trimodal therapy (TMT; chemoradiation plus surgery) and bimodal therapy (BMT; chemoradiation) have seldom been analysed. In a selective-surgery paradigm, the benefit of TMT in patients with a complete clinical response is controversial. Factors associated with survival in patients with a clinical complete response to chemoradiation were evaluated.

Methods

Patients with stage II–III oesophageal squamous cell carcinoma treated with TMT or BMT from 2002 to 2017 were evaluated. The BMT group consisted of patients who were otherwise eligible for surgery but underwent chemoradiation alone followed by observation. This group included patients who later had salvage oesophagectomy. Survival was evaluated and compared between TMT and BMT groups. Elastic net regularization was performed to select co-variables for Cox multivariable survival analysis in patients with a clinical complete response.

Results

Of 143 patients, 60 (41.9 per cent) underwent TMT and 83 (58.0 per cent) BMT. Patients who underwent TMT had longer median overall survival than those who had BMT (77 versus 33 months; P = 0.019). For patients with a clinical complete response, TMT achieved longer median overall survival than BMT (123 versus 55 months; P = 0.04). BMT had a high locoregional recurrence rate (48 versus 6 per cent; P < 0.001); 26 of 29 patients with locoregional recurrence in the BMT groupunderwent salvage resection. Cox multivariable analysis demonstrated that upper–mid oesophageal tumour location (hazard ratio (HR) 2.04; P = 0.024) and tumour length (HR 1.18; P = 0.046) were associated with worse survival. Although TMT was not associated with survival, it was a predictor of reduced recurrence (HR 0.28; P = 0.028). The maximum standardized uptake value after chemoradiation also predicted recurrence (HR 1.33; P < 0.001).

Conclusion

In patients who achieve a clinical complete response, TMT reduces locoregional recurrence but may not prolong survival. The differences in survival outcomes may be due to patient selection; therefore, a selective-surgery strategy in oesophageal squamous cell carcinoma is a reasonable approach.
Modelling the Impact of Vector Control on Lymphatic Filariasis Programs: Current Approaches and Limitations
Authors: Davis E L , Prada J , Reimer L J , Hollingsworth T D
Published: April 2021

Vector control is widely considered an important tool for lymphatic filariasis (LF) elimination but is not usually included in program budgets and has often been secondary to other policy questions in modelling studies. Evidence from the field demonstrates that vector control can have a large impact on program outcomes and even halt transmission entirely, but implementation is expensive. Models of LF have the potential to inform where and when resources should be focused, but often simplify vector dynamics and focus on capturing human prevalence trends, making them comparatively ill-designed for direct analysis of vector control measures. We review the recent modelling literature and present additional results using a well-established model, highlighting areas of agreement between model predictions and field evidence, and discussing the possible determinants of existing disagreements. We conclude that there are likely to be long-term benefits of vector control, both on accelerating programs and preventing resurgence.
Graft reduction surgery is associated with poorer outcome after lung transplantation: a single-centre propensity score-matched analysis
Authors: Montoya Pilar , Bello Irene , Ascanio Fernando , Romero Laura , Pérez Javier , Rosado Joel , Sánchez Leire , Sacanell Judith , Ribas Montserrat , Berastegui Cristina , Deu Maria , Jáuregui Alberto
Published: April 2021

OBJECTIVES

Implanted lung volume-reduction surgery due to donor/recipient size mismatch could affect both lung function and survival. We examined the outcomes of lung volume-reduction procedures post-lung transplant.

METHODS

We retrospectively reviewed 366 consecutive adult lung transplants carried out between January 2014 and December 2018 at one single centre. Patients were divided into either a non-reduced-size lung transplant or a reduced-size lung transplant (RT) group. To adjust for covariates, a propensity score analysis was performed. Survival was estimated using the Kaplan–Meier method. Differences were considered significant with P-values <0.05.

RESULTS

In the RT group, 45 patients (12.3%) had some type of graft reduction surgery: 31 (68.9%) patients had pulmonary lobectomies and 14 (31.1%) wedge resections. Of the total cohort, 30 patients (8.2%) were prioritized, 23% of whom required graft reduction surgery. The propensity score analysis matched 41 patients in each group. In the RT group, there was an increased need for cardiopulmonary bypass (P = 0.017) during surgery and extracorporeal membrane oxygenation (P = 0.025) after lung transplant. Furthermore, the median length of mechanical ventilation was higher (P = 0.008), and lung function at discharge, 3 and 6 months post-lung transplant was significantly lower in the RT group (P < 0.05). Survival analysis demonstrated a significantly poorer overall outcome at 1, 3 and 5 years post-lung transplantation in patients with a reduced graft (P = 0.007), while the 1-year conditional survival was also worse in this group (P = 0.025).

CONCLUSIONS

Graft reduction surgery in lung transplant recipients is associated with lower pulmonary function and poorer overall survival. However, it does allow transplantation in prioritized recipients for whom it might otherwise be impossible to find an organ of suitable size.
Atrial fibrillation and kidney function: a bidirectional Mendelian randomization study
Authors: Park Sehoon , Lee Soojin , Kim Yaerim , Lee Yeonhee , Kang Min Woo , Kim Kwangsoo , Kim Yong Chul , Han Seung Seok , Lee Hajeong , Lee Jung Pyo , Joo Kwon Wook , Lim Chun Soo , Kim Yon Su , Kim Dong Ki
Published: April 2021

Aims

The aim of this study was to investigate the causal effects between atrial fibrillation (AF) and kidney function.

Methods and results

We performed a bidirectional summary-level Mendelian randomization (MR) analysis implementing the results from a large-scale genome-wide association study for estimated glomerular filtration rate (eGFR) by the CKDGen (N = 765 348) and AF (N = 588 190) to identify genetic instruments. The inverse variance weighted method was the main MR method used. For replication, an allele score-based MR was performed by individual-level data within a UK Biobank cohort of white British ancestry individuals (N = 337 138). A genetic predisposition to AF was significantly associated with decreased eGFR [for log-eGFR, beta −0.003 (standard error, 0.0005), P < 0.001] and increased risk of chronic kidney disease [beta 0.059 (0.0126), P < 0.001]. The significance remained in MR sensitivity analyses and the causal estimates were consistent when we limited the analysis to individuals of European ancestry. Genetically predicted eGFR did not show a significant association with the risk of AF [beta −0.366 (0.275), P = 0.183]. The results were similar in allele score-based MR, as allele score for AF was significantly associated with reduced eGFR [for continuous eGFR, beta −0.079 (0.021), P < 0.001], but allele score for eGFR did not show a significant association with risk of AF [beta −0.005 (0.008), P = 0.530].

Conclusions

Our study supports that AF is a causal risk factor for kidney function impairment. However, an effect of kidney function on AF was not identified in this study.
A capture-based assay for detection and characterization of transposon polymorphisms in maize
Authors: Li Minqi , Noshay Jaclyn M , Dong Xiaoxiao , Springer Nathan M , Li Qing
Published: April 2021

Transposons can create allelic diversity that affects gene expression and phenotypic diversity. The detection of transposon polymorphisms at a genome-wide scale across a large population is difficult. Here, we developed a targeted sequencing approach to monitor transposon polymorphisms of interest. This approach can interrogate the presence or absence of transposons reliably across various genotypes. Using this approach, we genotyped a set of 965 transposon-related presence/absence polymorphisms in a diverse panel of 16 maize (Zea mays L.) inbred lines that are representative of the major maize breeding groups. About 70% of the selected regions can be effectively assayed in each genotype. The consistency between the capture-based assay and PCR-based assay are 98.6% based on analysis of 24 randomly selected transposon polymorphisms. By integrating the transposon polymorphisms data with gene expression data, ∼18% of the assayed transposon polymorphisms were found to be associated with variable gene expression levels. A detailed analysis of 18 polymorphisms in a larger association panel confirmed the effects of 10 polymorphisms, with one of them having a stronger association with expression than nearby SNP markers. The effects of seven polymorphisms were tested using a luciferase-based expression assay, and one was confirmed. Together, this study demonstrates that the targeted sequencing assay is an effective way to explore transposon function in a high-throughput manner.
Tales From the Front Lines: The Creative Essay as a Tool for Teaching Genetics
Authors: Koehler Kara E , Hawley R Scott
Published: April 2021

In contrast to the more typical mock grant proposals or literature reviews, we describe the use of the creative essay as a novel tool for teaching human genetics at the college level. This method has worked well for both nonmajor and advanced courses for biology majors. The 10- to 15-page essay is written in storylike form and represents a student's response to the choice of 6–8 scenarios describing human beings coping with various genetic dilemmas. We have found this tool to be invaluable both in developing students' ability to express genetic concepts in lay terms and in promoting student awareness of genetic issues outside of the classroom. Examples from student essays are presented to illustrate these points, and guidelines are suggested regarding instructor expectations of student creativity and scientific accuracy. Methods of grading this assignment are also discussed.
Reconstructing the Prior Probabilities of Allelic Phylogenies
Authors: Golding G Brian
Published: April 2021

In general when a phylogeny is reconstructed from DNA or protein sequence data, it makes use only of the probabilities of obtaining some phylogeny given a collection of data. It is also possible to determine the prior probabilities of different phylogenies. This information can be of use in analyzing the biological causes for the observed divergence of sampled taxa. Unusually “rare” topologies for a given data set may be indicative of different biological forces acting. A recursive algorithm is presented that calculates the prior probabilities of a phylogeny for different allelic samples and for different phylogenies. This method is a straightforward extension of Ewens' sample distribution. The probability of obtaining each possible sample according to Ewens' distribution is further subdivided into each of the possible phylogenetic topologies. These probabilities depend not only on the identity of the alleles and on 4Nμ (four times the effective population size times the neutral mutation rate) but also on the phylogenetic relationships among the alleles. Illustrations of the algorithm are given to demonstrate how different phylogenies are favored under different conditions.
Genetic Analysis of Early Flowering Mutants in Arabidopsis Defines a Class of Pleiotropic Developmental Regulator Required for Expression of the Flowering-Time Switch Flowering Locus C
Authors: Zhang Hua , Ransom Callista , Ludwig Philip , van Nocker Steven
Published: April 2021

The Arabidopsis flowering-repressor gene FLOWERING LOCUS C (FLC) is a developmental switch used to trigger floral induction after extended growth in the cold, a process termed vernalization. In vernalized plants, FLC becomes transcriptionally silenced through a process that involves an epigenetic mechanism. We identified recessive mutations designated vernalization independence (vip) that confer cold-independent flowering and suppression of FLC. These mutations also lead to developmental pleiotropy, including specific defects in floral morphology, indicating that the associated genes also have functions unrelated to flowering time. We identified the VIP3 gene by positional cloning and found that it encodes a protein consisting almost exclusively of repeated Trp-Asp (WD) motifs, suggesting that VIP3 could act as a platform to assemble a protein complex. Constitutive transgenic expression of VIP3 in vernalized plants is insufficient to activate FLC, and thus VIP3 probably participates in the regulation of FLC as one component of a more extensive mechanism. Consistent with this, genetic analyses revealed that the VIP loci define a functional gene class including at least six additional members. We suggest that VIP3 and other members of this gene class could represent a previously unrecognized flowering mechanism.
DNA Polymorphism in the β-EsteraseGene Cluster ofDrosophila melanogaster
Authors: Balakirev Evgeniy S , Chechetkin V R , Lobzin V V , Ayala Francisco J
Published: April 2021

We have analyzed nucleotide polymorphism within a 5.3-kb region encompassing the functional Est-6 gene and the ψEst-6 putative pseudogene in 28 strains of Drosophila melanogaster and one of D. simulans. Two divergent sequence types were detected, which are not perfectly associated with Est-6 allozyme variation. The level of variation (π) is very close in the 5′-flanking region (0.0059) and Est-6 gene (0.0057), but significantly higher in the intergenic region (0.0141) and putative pseudogene (0.0122). The variation in the 3′-flanking region is intermediate (0.0083). These observations may reflect different levels of purifying selection in the different regions. Strong linkage disequilibrium occurs within the region studied, with the largest values revealed in the putative pseudogene and 3′-flanking region. Moreover, recombination is restricted within ψEst-6. Gene conversion is detected both within and (to a lesser extent) between Est-6 and ψEst-6. The data indicate that ψEst-6 exhibits some characteristics that are typical of nonfunctional genes, while other characteristics are typically attributed to functional genes; the same situation has been observed in other pseudogenes (including Drosophila). The results of structural entropy analysis demonstrate higher structural ordering in Est-6 than in ψEst-6, in accordance with expectations if ψEst-6 is indeed a pseudogene. Taking into account that the function of ψEst-6 is not known (but could exist) and following the terminology of J. Brosius and S. J. Gould, we suggest that the term “potogene” may be appropriate for ψEst-6, indicating that it is a potential gene that may have acquired some distinctive but unknown function.
PrBn, a Major Gene Controlling Homeologous Pairing in Oilseed Rape (Brassica napus) Haploids
Authors: Jenczewski Eric , Eber Frédérique , Grimaud Agnès , Huet Sylvie , Lucas Marie Odile , Monod Hervé , Chèvre Anne Marie
Published: April 2021

Precise control of chromosome pairing is vital for conferring meiotic, and hence reproductive, stability in sexually reproducing polyploids. Apart from the Ph1 locus of wheat that suppresses homeologous pairing, little is known about the activity of genes that contribute to the cytological diploidization of allopolyploids. In oilseed rape (Brassica napus) haploids, the amount of chromosome pairing at metaphase I (MI) of meiosis varies depending on the varieties the haploids originate from. In this study, we combined a segregation analysis with a maximum-likelihood approach to demonstrate that this variation is genetically based and controlled mainly by a gene with a major effect. A total of 244 haploids were produced from F1 hybrids between a high- and a low-pairing variety (at the haploid stage) and their meiotic behavior at MI was characterized. Likelihood-ratio statistics were used to demonstrate that the distribution of the number of univalents among these haploids was consistent with the segregation of a diallelic major gene, presumably in a background of polygenic variation. Our observations suggest that this gene, named PrBn, is different from Ph1 and could thus provide complementary information on the meiotic stabilization of chromosome pairing in allopolyploid species.
Characterization of High-Copy-Number Retrotransposons From the Large Genomes of the Louisiana Iris Species and Their Use as Molecular Markers
Authors: Kentner Edward K , Arnold Michael L , Wessler Susan R
Published: April 2021

The Louisiana iris species Iris brevicaulis and I. fulva are morphologically and karyotypically distinct yet frequently hybridize in nature. A group of high-copy-number TY3/gypsy-like retrotransposons was characterized from these species and used to develop molecular markers that take advantage of the abundance and distribution of these elements in the large iris genome. The copy number of these IRRE elements (for iris retroelement), is ∼1 × 105, accounting for ∼6–10% of the ∼10,000-Mb haploid Louisiana iris genome. IRRE elements are transcriptionally active in I. brevicaulis and I. fulva and their F1 and backcross hybrids. The LTRs of the elements are more variable than the coding domains and can be used to define several distinct IRRE subfamilies. Transposon display or S-SAP markers specific to two of these subfamilies have been developed and are highly polymorphic among wild-collected individuals of each species. As IRRE elements are present in each of 11 iris species tested, the marker system has the potential to provide valuable comparative data on the dynamics of retrotransposition in large plant genomes.
Estimating Mutation Rate: How to Count Mutations?
Authors: Fu Yun-Xin , Huai Haying
Published: April 2021

Mutation rate is an essential parameter in genetic research. Counting the number of mutant individuals provides information for a direct estimate of mutation rate. However, mutant individuals in the same family can share the same mutations due to premeiotic mutation events, so that the number of mutant individuals can be significantly larger than the number of mutation events observed. Since mutation rate is more closely related to the number of mutation events, whether one should count only independent mutation events or the number of mutants remains controversial. We show in this article that counting mutant individuals is a correct approach for estimating mutation rate, while counting only mutation events will result in underestimation. We also derived the variance of the mutation-rate estimate, which allows us to examine a number of important issues about the design of such experiments. The general strategy of such an experiment should be to sample as many families as possible and not to sample much more offspring per family than the reciprocal of the pairwise correlation coefficient within each family. To obtain a reasonably accurate estimate of mutation rate, the number of sampled families needs to be in the same or higher order of magnitude as the reciprocal of the mutation rate.
An Argonaute-Like Protein Is Required for Meiotic Silencing
Authors: Lee Dong W , Pratt Robert J , McLaughlin Malcolm , Aramayo Rodolfo
Published: April 2021

We demonstrate the involvement of suppressor of meiotic silencing-2 (sms-2+), a Neurospora gene coding for an Argonaute-like protein, in meiotic silencing and normal sexual development.
False Discovery Rate in Linkage and Association Genome Screens for Complex Disorders
Authors: Sabatti Chiara , Service Susan , Freimer Nelson
Published: April 2021

We explore the implications of the false discovery rate (FDR) controlling procedure in disease gene mapping. With the aid of simulations, we show how, under models commonly used, the simple step-down procedure introduced by Benjamini and Hochberg controls the FDR for the dependent tests on which linkage and association genome screens are based. This adaptive multiple comparison procedure may offer an important tool for mapping susceptibility genes for complex diseases.