bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a self-driving car prototype for educational and research purposes
Authors: Fan X , Zhang Z , Wang Y
Published: May 2021

Self-driving car (SDC) is one of the most challenging topics in artificial intelligence. However, current off-the-shelf SDC platforms are expensive and difficult to modify, which prevents more researchers from working towards the improvement of self-driving technologies. This paper presents the development of a SDC prototype with low-cost sensors and an open-source software platform for educational and academic research purposes. The goal of such a SDC prototype is to serve as a testbench, which allows students and researchers to easily test new algorithms of SDC. Localization is one of the most basic and important problems in SDC. To achieve high performance using low-cost sensors, a localization method based on Lidar-INS fusion was investigated under the framework of Kalman filtering. Autonomous driving experiments were conducted on roads of a university campus environment and the results are used to show the performance.
An ADRC-based Stick-slip Vibration Control Method for Drill String
Authors: Shuguang Liu , Wuyang Chen , Kecheng Wu , Jia Jiang
Published: May 2021

For complex deep wells, the drill string stick-slip vibration is a intensive destructiveness torsional vibration caused by twisting vibration and down hole drag. This phenomenon can be explained that the bit is motionless for some time, and when the torque on drill string is large enough, the bit suddenly rotate at a high-speed. The stick-slip vibration has become a major problem to be solved urgently in the exploration and exploitation of deep and ultra-deep wells. In drilling operations, the stick-slip will occur in drilling for more than half of the time. Usually, the stick-slip vibration leads to the decrease of penetration rate and the increase of completion cycle. In serious cases, it leads to drill string fracture, bit failure, and even serious downhole accidents. In this thesis, the drill string torsion model is established, the drill string stick-slip vibration mechanical model is proposed, the equation of stick-slip vibration motion is analyzed and the general laws of drill string stick-slip vibration are acquired. In order to effectively suppress stick-slip vibration, an auto-disturbance rejection control (ADRC) method is adopted. Result of experiment shows that the soft-torque control method can make the actual speed of motor changed according to the torque, so as to decrease the motor torque fluctuations, eliminate stick-slip vibration and achieve the drill string soft-torque control.
Surface Topography of the Metal surface in Robot Polishing under Control Force
Authors: Zhao Wenliang , Mohsin Imran , Huang Longlong , He Kai
Published: May 2021

Polishing is an important finishing process in the field of manufacturing, which enhances product quality and increases its life span. Compared with manual polishing, robotics polishing has advantages in terms of cost and productivity. This paper presents a new study on the surface topography of metal workpiece in the robotic polishing test. Various workpieces with different surface roughness were polished with the industrial robot under similar polishing parameters, and the variation of surface topography with polishing was studied utilizing microscopic scanning.
Autonomous vehicle adoption: use phase environmental implications
Authors: Kontar Wissam , Ahn Soyoung , Hicks Andrea
Published: May 2021

This paper investigates the environmental trade offs resulting from the adoption of autonomous vehicles (AVs) as a function of modal shifts and use phase. An empirical approach is taken to formulate a mode choice model informed from a stated preference (SP) survey conducted in Madison, Wisconsin. A life cycle analysis based on well-to-wheel model is then conducted to quantify the use phase environmental impacts across different categories. The mode choice analysis reveals the potential users of AVs and its attractiveness as a mode of transportation, ultimately competing with traditional modes available. This translates into modal shifts that are shown to result in an expected increase in environmental impacts across all studied categories: energy consumption (5.93%), greenhouse gas emissions (5.72%), particulate matter (6.80%), sulfur (6.85%) and nitrogen oxides (5.70%). The adoption of electric AVs (E-AVs) is then analyzed as an offsetting strategy to combat the increase in environmental impacts. The analysis reveals that E-AVs are capable of offsetting the foreseen impacts, yet their effectiveness is dependent on the electricity generation mix and adoption rate.
How unprecedented was the February 2021 Texas cold snap?
Authors: Doss-Gollin James , Farnham David J , Lall Upmanu , Modi Vijay
Published: May 2021

Winter storm Uri brought severe cold to the southern United States in February 2021, causing a cascading failure of interdependent systems in Texas where infrastructure was not adequately prepared for such cold. In particular, the failure of interconnected energy systems restricted electricity supply just as demand for heating spiked, leaving millions of Texans without heat or electricity, many for several days. This motivates the question: did historical storms suggest that such temperatures were known to occur, and if so with what frequency? We compute a temperature-based proxy for heating demand and use this metric to answer the question ‘what would the aggregate demand for heating have been had historic cold snaps occurred with today’s population?’. We find that local temperatures and the inferred demand for heating per capita across the region served by the Texas Interconnection were more severe during a storm in December 1989 than during February 2021, and that cold snaps in 1951 and 1983 were nearly as severe. Given anticipated population growth, future storms may lead to even greater infrastructure failures if adaptive investments are not made. Further, electricity system managers should prepare for trends in electrification of heating to drive peak annual loads on the Texas Interconnection during severe winter storms.
Biomass partitioning of C3- and C4-dominated grasslands in response to climatic variability and climate extremes
Authors: Hossain Md Lokman , Li Jianfeng
Published: May 2021

The rising temperature, altering precipitation, and increasing extreme events under climate warming affect the stability and sustainability of grassland ecosystems. The dynamics of above-ground biomass (AGB), below-ground biomass (BGB), and biomass partitioning (BGB:AGB ratio) of grasslands are of fundamental importance to understand their feedback to climate change. In this study, we used grassland productivity data extracted from the Oak Ridge National Laboratory Distributed Active Archive Center, Tennessee, USA, in which the AGB was collected within a 1.0 m × 0.25 m quadrat and the BGB was sampled within the center of the quadrat. Using multiple pairwise tests and Pearson’s correlation analysis, we assessed the variations of grassland productivity and examined the response of single-harvest and annual biomass partitioning of C3- and C4-dominated grasslands to the growing-season and annual climatic variability and climate extremes in seven sites belonging to four ecoregions (i.e. cold steppe, humid temperate, humid savanna, and savanna). The results show that the annual and single-harvest BGB:AGB ratio varied significantly across the plant types and ecoregions. Overall, the C3-dominated grasslands exhibited a higher BGB:AGB ratio than that of C4-dominated grasslands. Growing-season temperatures (GSTs) were found to be the key determinants in explaining the single-harvest BGB:AGB ratio rather than growing-season precipitation. For instance, the single-harvest BGB:AGB ratio of C4-dominated grasslands increased, while that of C3-dominated grasslands decreased with elevated GSTs. The growing-season extreme dry climates significantly increased the single-harvest BGB:AGB ratio of C4 plants by a large reduction of AGB, potentially affecting the ecosystem functioning and stability. The C3-dominated grasslands in the cold steppe ecoregion are at great threat of drought-induced stress, as we observed that growing-season extreme dry climates reduced, albeit insignificantly, both the single-harvest AGB and BGB. This study provides key insights into factors influencing the biomass partitioning of C3- and C4-dominated grasslands and has important implications for assessing the grassland functioning and stability under increasing climate extremes.
Excited Rydberg states in MoSe2/WSe2 heterostructures
Authors: Viner Jacob J S , McDonnell Liam P , Ruiz-Tijerina David A , Rivera Pasqual , Xu Xiaodong , Fal’Ko Vladimir I , Smith David C
Published: May 2021

The functional form of Coulomb interactions in the transition metal dichalcogenides (TDMs) and other van der Waals solids is critical to many of their unique properties, e.g. strongly-correlated electron states, superconductivity and emergent ferromagnetism. This paper presents measurements of key excitonic energy levels in MoSe2/WSe2 heterostructures. These measurements are obtained from resonance Raman experiments on specific Raman peaks only observed at excited states of the excitons. This data is used to validate a model of the Coulomb potential in these structures which predicts the exciton energies to within ∼5 meV. This model is used to determine the effect of heterostructure formation on the single-particle band gaps of the layers and will have a wide applicability in designing the next generation of more complex TDM structures.
Assessment of a commercial EPID dosimetry system to detect radiotherapy treatment errors
Authors: Doolan Paul , Nikolaou Maria , Ferentinos Konstantinos , Anagnostopoulos Georgios
Published: May 2021

One method for detecting radiotherapy treatment errors is to capture the exit dose using an electronic portal imaging device. In comparison with a baseline integrated image, subsequent fractions can be compared and differences in images suggest a difference in the radiation treatment delivered. The aim of this work was to assess the sensitivity of a commercial software PerFRACTION in detecting such differences, arising from three possible sources: (i) changes in the radiation beam or EPID position; (ii) changes in the patient position; and (iii) changes in the patient anatomy. By systematically introducing errors, PerFRACTION was shown to be very sensitive to changes in the radiation beam. Variation in the beam output could be detected within 0.3%, field size within 0.4 mm, collimator rotation within 0.3° and MLC positioning could be verified to within 0.1 mm. EPID misalignment could be detected within 0.3 mm. PerFRACTION was able to detect the mispositioning of an anthropomorphic phantom by 3 mm with static beams, however there was a relative dependency between the patient geometry and the direction of the shift. VMAT beams were less sensitive to patient misalignments, with a shift of 10 mm only detectable once a strict criterion of 1% dose difference was applied. In another simulated scenario PerFRACTION was also able to detect a weight loss equivalent to a 5 mm change in patient separation in VMAT plans and 10 mm in conformal plans. This work showed that the PerFRACTION software could be relied upon to detect potential radiotherapy treatment errors, arising from a variety of sources.
Metric rigidity of Kähler manifolds with lower Ricci bounds and almost maximal volume
Authors: Datar Ved , Seshadri Harish , Song Jian
Published: May 2021

In this short note we prove that a Kähler manifold with lower Ricci curvature bound and almost maximal volume is Gromov-Hausdorff close to the projective space with the Fubini-Study metric. This is done by combining the recent results on holomorphic rigidity of such Kähler manifolds (see Gang Liu [Asian J. Math. 18 (2014), 69–99]) with the structure theorem of Tian-Wang (see Gang Tian and Bing Wang [J. Amer. Math. Soc 28 (2015), 1169–1209]) for almost Einstein manifolds. This can be regarded as the complex analog of the result on Colding on the shape of Riemannian manifolds with almost maximal volume.
The impact of additional payments on functional decline among long-term care health facility residents in Japan
Authors: Jin Xueying , Tamiya Nanako , Uda Kazuaki , Yasunaga Hideo
Published: May 2021

Background

Additional payment approach has been one of the most important incentives in long-term care (LTC) systems for the past 20 years in Japan.

Objective

To estimate the effect of additional payments on functional decline in long-term care health facility (LTCHF) residents of Japan.

Design

A 24-month retrospective cohort study.

Setting and subjects

Residents aged ≥65 years who were newly admitted to LTCHFs in the 2014 fiscal year.

Methods

National LTC claims data were linked to the survey of institutions and establishments for LTC. Competing risk regression was performed with functional decline as the primary outcome, and additional payments as exposure, controlling for individual and facility characteristics. The level of LTC needs certified in the LTC insurance system was applied as a proxy of functional ability. Death, hospitalisation, discharge to home and transfer to other LTC facilities were treated as competing events. Individual- and facility-level additional payments were presented as binary variables: being reimbursed or not during the follow-up period.

Results

At baseline, 146,311 residents from 3,724 LTCHFs were included. The vast majority of additional payments were associated with a lower risk of functional decline at follow-up. At the individual level, additional payment for pre/post admission instructions had the strongest association with a lower risk of functional decline. Despite this, only 8% of residents were reimbursed for this additional payment. At the facility level, residents in LTCHFs with additional payments for support for home-life resumption and nutritional management were associated with a decreased risk of functional decline.

Conclusions

The results of our study may be of particular interest to policymakers in monitoring and evaluating additional payment approaches and provide insight into improving quality of care.
SMARCA4-Deficient Undifferentiated Tumor Diagnosed on Adrenal Sampling
Authors: Ashour Salam , Reynolds Jordan P , Mukhopadhyay Sanjay , McKenney Jesse K
Published: May 2021

Objectives

SMARCA4-deficient undifferentiated tumor has distinct clinicopathologic features. We describe our experience with primary diagnosis on adrenal sampling.

Methods

We collected six SMARCA4-deficient undifferentiated tumors diagnosed on adrenal sampling. Immunostains for SMARCA4, SF-1, inhibin, calretinin, S-100 protein, EMA, and TTF-1 were performed. A control group of 63 primary adrenocortical tumors was also immunostained.

Results

Patients included four men and two women (aged 52-77 years). Five had unilateral adrenal masses and one bilateral (range, 2.4-9.6 cm). Five had pulmonary masses, and one had a midline mediastinal mass. All cases had a monotonous epithelioid appearance and variable rhabdoid morphology. Immunophenotypically, all six cases had loss of nuclear SMARCA4 expression and no staining for SF-1, inhibin, calretinin, or S-100 protein. Variable EMA immunoreactivity was present in four of six cases and focal nuclear TTF-1 expression in one of six. All 63 adrenocortical neoplasms had retained nuclear SMARCA4 expression.

Conclusions

SMARCA4-deficient undifferentiated tumor may present in the adrenal gland, and this series likely represents metastases from thoracic primaries. Because of the frequent absence of lineage marker expression, knowledge of the characteristic clinical presentation, the rhabdoid morphology, and the typical immunophenotype (loss of SMARCA4/BRG1) allow for appropriate distinction from adrenocortical carcinoma.
Review of Quantitative Imaging for Objective Assessment of Fat Grafting Outcomes in Breast Surgery
Authors: Sampathkumar Urmila , Nowroozilarki Zhale , Bordes Mary Catherine , Reece Gregory P , Hanson Summer E , Markey Mia K , Merchant Fatima A
Published: May 2021

This article presents a comprehensive review of the use of quantitative measurements based on breast images to assess fat retention, breast aesthetics, and fat necrosis after autologous fat grafting. Breast volume measured from MRI and 3-dimensional surface images is widely used as a measure of fat retention. Breast aesthetics are assessed from a combination of anthropometric (distance and contour) measurements on breast surface images. Examination of radiologic images (ultrasonography, mammography, and MRI) is utilized to assess fat necrosis. The article discusses implementation guidelines for objective outcome assessment to support robust quantification and enable investigations of fat grafting efficacy.

Level of Evidence: 4
Assessing Clinical Outcomes in Autologous Fat Grafting: A Current Literature Review
Authors: Moak Teri N , Ebersole Trina G , Tandon Damini , Tenenbaum Marissa
Published: May 2021

Autologous fat grafting, first described in the 1890s, has since undergone many modifications to optimize safety and efficacy. These changes have resulted in the technique that we now consider standard of care, one that is applied to reconstruction and cosmetic enhancement of the breast and the face both independently and in conjunction with surgical treatment. There is a growing body of evidence that this application has positive outcomes for patient satisfaction, surgeon satisfaction, and overall aesthetic appearance. This article summarizes the body of literature regarding these outcomes, reviews complications of fat grafting in the face and breast, and discusses controversies including radiologic imaging changes and longevity of grafting.

Level of Evidence: 4
Males benefit personally from family life: evidence from a wild burying beetle population
Authors: Keppner Eva M , Steiger Sandra
Published: May 2021

Family life in animals is often considered as beneficial for offspring but costly for parents. However, parents might also profit from remaining aggregated within a family unit, especially if a nutrient-rich resource is used for reproduction. We aimed to reveal the potential personal benefits of breeding within a family environment for male Nicrophorus vespilloides, a species of burying beetles that use small vertebrate cadavers to raise their larvae. We previously hypothesized that males obtain an advantage from remaining with their family, because they themselves can feed from the cadaver. This, in turn, enables them to produce more sex pheromone, thereby making them more attractive to females after leaving their brood. However, whether such personal benefits arise under natural conditions is currently unclear because we have no knowledge of the nutritional condition of wild beetles. If carrion is abundant anyways, feeding from a vertebrate cadaver during breeding might not have a noticeable positive effect on the males’ body condition. In the current study, we caught wild males with a natural feeding history and compared their body mass and attractiveness before and after participating in family life. We show that wild males gain weight during breeding and attract more and larger females afterwards. Our study suggests that access to a highly nutrient-rich meal can be a driver of the evolution of family life and eventually biparental care. Males benefit indirectly from defending the resource and offspring against competitors and benefit personally by a higher chance of mating again after breeding.
Distinct effect of prenatal and postnatal brain expression across 20 brain disorders and anthropometric social traits: a systematic study of spatiotemporal modularity
Authors: Jia Peilin , Manuel Astrid M , Fernandes Brisa S , Dai Yulin , Zhao Zhongming
Published: May 2021

Different spatiotemporal abnormalities have been implicated in different neuropsychiatric disorders and anthropometric social traits, yet an investigation in the temporal network modularity with brain tissue transcriptomics has been lacking. We developed a supervised network approach to investigate the genome-wide association study (GWAS) results in the spatial and temporal contexts and demonstrated it in 20 brain disorders and anthropometric social traits. BrainSpan transcriptome profiles were used to discover significant modules enriched with trait susceptibility genes in a developmental stage-stratified manner. We investigated whether, and in which developmental stages, GWAS-implicated genes are coordinately expressed in brain transcriptome. We identified significant network modules for each disorder and trait at different developmental stages, providing a systematic view of network modularity at specific developmental stages for a myriad of brain disorders and traits. Specifically, we observed a strong pattern of the fetal origin for most psychiatric disorders and traits [such as schizophrenia (SCZ), bipolar disorder, obsessive–compulsive disorder and neuroticism], whereas increased co-expression activities of genes were more strongly associated with neurological diseases [such as Alzheimer’s disease (AD) and amyotrophic lateral sclerosis] and anthropometric traits (such as college completion, education and subjective well-being) in postnatal brains. Further analyses revealed enriched cell types and functional features that were supported and corroborated prior knowledge in specific brain disorders, such as clathrin-mediated endocytosis in AD, myelin sheath in multiple sclerosis and regulation of synaptic plasticity in both college completion and education. Our study provides a landscape view of the spatiotemporal features in a myriad of brain-related disorders and traits.
Family Rank: a graphical domain knowledge informed feature ranking algorithm
Authors: Saul Michelle , Dinu Valentin
Published: May 2021

Motivation

When designing prediction models built with many features and relatively small sample sizes, feature selection methods often overfit training data, leading to selection of irrelevant features. One way to potentially mitigate overfitting is to incorporate domain knowledge during feature selection. Here, a feature ranking algorithm called ‘Family Rank’ is presented in which features are ranked based on a combination of graphical domain knowledge and feature scores computed from empirical data.

Results

A simulated dataset is used to demonstrate a scenario in which family rank outperforms other state-of-the-art graph based ranking algorithms, decreasing the sample size needed to detect true predictors by 2- to 3-fold. An example from oncology is then used to explore a real-world application of family rank.

Availability and implementation

An implementation of Family Rank is freely available at https://cran.r-project.org/package=FamilyRank.

Supplementary information

Supplementary data are available at Bioinformatics online.
HEPARIN AS AN ANTIBACTERIAL COATING ON BIODEGRADABLE URETERAL STENTS: EXPERIMENTAL STUDY OF BRAIDSTENT®-H
Authors: E de la Cruz Conty J , Budía Alba A , Sanz Migueláñez J L , Galán Llopis J A , Fernández Aparicio T , Sánchez Margallo F M , Soria Gálvez F
Published: May 2021

INTRODUCTION

The aim of this study is to assess the effectiveness of heparin to inhibit the development of early bacteriuria as a coating for biodegradable ureteral stents.

MATERIAL AND METHODS

The BraidStent®-H biodegradable stent, whose heparin coating is incorporated by dip coating, was chosen for this study. Twenty-four swine were randomly divided into two groups: 12 animals underwent unilateral placement of the BraidStent®-H and 12 were fitted with a standard double-j stent (DJS). Bacteriuria is comparatively analyzed over time by consecutive urine sampling at 0, 1, 3, 6, 12, 24 and 48 hours. In addition, the concentration of heparin released in vitro in artificial urine at 0, 3, 6, 12, 24, 48, 72, 92 and 120 hours is determined via ELISA.

RESULTS

BraidStent®-H generates a significantly lower bacteriuria rate than a DJS at 6 and 12 hours. Heparin coating shows a significant delaying effect on the onset of bacteriuria, reaching 100% of the animals at 48 hours, compared to the DJS, which takes place at 6 hours. ELISA results reveal the presence of heparin in urine for a total of 72 hours. The coating does not affect the degradation of the device, which is completed at 6 weeks.

CONCLUSIONS

Heparin evidences an effective inhibition of early bacteriuria, showing its potential as an antibacterial coating for biodegradable ureteral stents. Future studies should focus on the development of long-term heparin coatings for biodegradable materials.
INTERVENTIONAL PULMONARY ASSISTANCE (iLA) AS A BRIDGE TO LUNG TRANSPLANTATION
Authors: Burgos Frías N , Córdoba Peláez M , Sánchez Calle A , Campo Cañaveral J L , Martínez López D , Serrano-Fiz García S , Varela Ugarte A , Burgos Lázaro R J
Published: May 2021

INTRODUCTION

According to the “International Society for Heart and Lung Transplantation” (ISHLT), between 1 and 4% of patients awaiting a lung transplant will need some type of respiratory assistance as a bridge to transplantation. The objective of this study is to analyze the results of patients assisted with the iLA “Interventional Lung Assist” system (Novalung®).

MATERIAL AND METHODS

The iLA respiratory assistance system (Novalung®) has been used in 12 patients as a bridge to lung transplantation (three chronic obstructive pulmonary disease, five obliterative bronchiolitis, two pulmonary fibrosis, one chest trauma, one pulmonary leiomyomatosis). The gasometric parameters that indicated the assistance were: PaO2: 76.1 ± 29; PaCO2: 110.6 ± 49; pH: 7.12 ± 0.1. The patients were anticoagulated with intravenous sodium heparin (aPTT 160-180 seconds).

RESULTS

Six hours after the start of respiratory assistance, the gasometric parameters were: PaO2: 89 ± 17 (p > 0.05); PaCO2: 54.6 ± 5 (p < 0.05); pH 7.34 ± 0.1 (p < 0.05). The mean time of attendance was 16.8 ± 8 (4-28) days. Of the total number of patients attended: one died during the care and the remaining 11 were transplanted, of which 8 survived the lung transplant.

CONCLUSIONS

Respiratory assistance using iLA (Novalung®) has proven to be an effective method as a bridge to lung transplantation. It allows to improve lung function and avoid mechanical ventilation. It is indicated in patients with nonpermissive hypercapnia to avoid mechanical ventilation. In mechanically ventilated patients, iLA assistance improves ventilator tidal volume, FiO2 and PEEP.
BIOMECHANICS OF A NEW TECHNIQUE FOR FLEXOR TENDON TENORRAPHY OF THE HAND
Authors: García Cabeza S , Lara Guerrero M , Salinas Ramila F , Martínez Magide G J , Carnero López S , Martín Muñiz C , Pérez Arias A , Camporro Fernández D
Published: May 2021

INTRODUCTION

The present study compares ultimate tensile strength, gap strength (2, 4, 6 mm), distortion time and breaking time in a new flexor tendon suture, to a conventional technique.

MATERIAL AND METHODS

The flexor digitorum profundus tendons of 40 porcine forelimbs were repaired. The biomechanical analysis was carried out in a universal testing machine applying a constant speed. Tenotomy gap, the force applied and the rupture point were analysed.

RESULTS

The ultimate tensile strength, and 4 and 6 mm gap strength were significantly higher with the new technique compared with the conventional 4-strand cruciate technique.

CONCLUSIONS

The new technique is a higher provider of repair strength during early active mobilization when compared with the conventional 4-strand cruciate technique. These findings suggest that this new suture can be considered a biomechanically favourable technique for the repair of flexor tendon lacerations.
DIAGNOSTIC ACCURACY IN RESECABLE ESOPHAGEAL CANCER
Authors: Andres Imaz A , Martí Gelonch l , Echeveste Varela A , Ariño Hervas I , Eizaguirre Letamendia E , Asensio Gallego J I , Murgoitio Lazcano F J , Enríquez Navascués J M
Published: May 2021

INTRODUCTION

In localized oesophageal cancer (EC), a correct clinical tumor staging is essential in order to offer an optimal treatment, although often challenging. The aim of this work is to assess the accuracy of the diagnostic tests by comparing them with the pathological staging.

MATERIAL AND METHODS

Retrospective observational study of patients who underwent oesophagectomy for cancer in a referral hospital between January 2003 and September 2019. Those patients who received neoadjuvant treatment were excluded in order to avoid bias from dowstaging effects. The preoperative stage cT and cN as well as the combination of both (cTNM) were compared with the pathological stage of the surgical specimen (pT, pN, pTNM), considered the gold standard. Computed tomography (CT) and endoscopic ultrasound (EUS) were evaluated for cT and cN, while Positron emission tomography (PET/CT) only for cN. Furthermore, the pT stage was correlated with the tumor length described in the oesophagogram (EG).

RESULTS

Among the 63 patients included, the clinical staging was correct in 16 cases (global accuracy 25.4%), it was overstaged in 21 (33.2%) and understaged in 26 (41.3%). For cT staging, the accuracy of EUS was higher than that of CT (46.6% and 34.9% respectively), specially for early stages. EG tumor length correlated with pT stage (p < 0.05). For cN staging, PET/CT had the highest sensitivity (50.0%) and NPV (75.0%).

CONCLUSIONS

Despite the multiple diagnostic tools used, the global accuracy of clinical staging in localized EC is still a challenge, with the therapeutic and prognostic implications that this entails.
SURGICAL TREATMENT IN RAYNAUD'S DISEASE
Authors: Núñez García B , Álvarez García N , Pérez-Gaspar M , Esteva Miró C , Betancourth Alvarenga J E , Jiménez Gómez J , Santiago Martínez S , Jiménez Arribas P
Published: May 2021

INTRODUCTION

In primary or refractory cases of Raynaud's Disease (RD), with severe symptoms (pain, ulcers, and disability), minimally invasive surgical treatments such as thoracoscopic sympathectomy have recently been proposed.

The objective of this study will be to evaluate the viability, feasibility and results of this therapeutic option in this type of patient.

MATERIAL AND METHODS

Descriptive prospective study from January 2017 to January 2019 where all patients with a diagnosis of RD, with poor clinical control and disability, and refractory to medical treatment are collected.

RESULTS

Seven girls (9-15 years old) were collected. All underwent bilateral thoracoscopic sympathectomy, T2-T4, with a mean surgical time of 55 min. No need for pleural drainage. All of them were discharged before 36 hours after surgery (12-36 hours) without any immediate intra or postoperative complications.

All reported an immediate postoperative period without incident, without new episodes of pain or intense vasoconstriction. However, 6 months after surgery, 3 of the 7 (42.85%) presented partial reappearance of the symptoms. However, the 7 presented 100% satisfaction with the surgical results.

CONCLUSIONS

There are currently very few published studies regarding this surgical option.

We believe that our series is the first pediatric series to be collected, although it is very limited. However, the results obtained to date, in global terms, are encouraging.

We consider that thoracoscopic sympathectomy is a feasible and safe surgical technique to consider in patients with RD refractory to conservative treatment.
CURCUMIN PREVENTING INTESTINAL ISCHEMIA-REPERFUSION INJURY
Authors: Velasco X , Herrero de la Parte B , Palomares T , García-Alonso I
Published: May 2021

INTRODUCTION

Ischemia-reperfusion injury is a clinically relevant process. Several drugs have been tested to prevent or reduce its deleterious effects. Curcumin is a natural substance, common in many diets, known to have antioxidant proprieties. Our aim is to check its capacity to prevent intestinal reperfusion injury.

METHODS

Four groups of six WAG/RijHsd rats (males, 240 g). Three of them had 1 h clamping of the superior mesenteric artery, being sacrificed 4 hours later. One of these groups received no other treatment (control), other was given Curcumin 24h and 2 h prior to ischemia (200 mgr/kg, oral), and the third one was given alpha-Tocopherol 2h prior to ischemia (20 mgr/kg, ip). To assess histological injury four samples from distal ileon were retrieved from each animal. Once embedded in paraffin, histological sections were stained with H-E and blinded, prior to assessing the damage according to Chiu’s scale. Results were analyzed with ANOVA & Dunnet’s and Sidak’s multiple comparison tests.

RESULTS

In healthy animals, over a scale ranging from 0 to 12, the damaged registered was 0.92 ± 0.56. Ischemic control animals showed an index damage of 10.14 ± 1.43, while those receiving Curcumin only reached 6.15 ± 1.71. Animas pre-treated with alpha-Tocopherol showed an even lower index damage: 4.05 ± 0.62. So both treatments significantly reduced histological damage following intestinal reperfusion (p < 0.0001), being slightly bigger the effect of alpfa-Tocopherol (p < 0.05).

CONCLUSION

Curcumin given the day before significantly reduces intestinal reperfusion injury, though it does is as much effective as alpha-Tocopherol pre-treatment.
NEW MOLECULAR RECEPTORS FOR DIAGNOSIS AND THERAPY OF PANCREATIC DUCTAL ADENOCARCINOMA
Authors: Lorenzo Gómez R , Miranda Castro R , García Ocaña M , de los Toyos J R , Barneo L , de los Santos Álvarez N , Lobo Castañón M J
Published: May 2021

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDAC) is one of the cancers with worst prognosis due to the intense desmoplastic reaction that occurs in this disease, which hinders the action of therapeutic agents and contributes to cancer progression. A possible way to develop new strategies for PDAC diagnosis and therapy is the study of the abnormal components of the tumor stroma. However, new receptors capable of detecting these components are needed.

MATERIALS AND METHODS

Two types of molecular receptors, monoclonal antibodies and aptamers, were developed in parallel targeting an extracellular matrix protein with potential as a PDAC marker. Antibodies were generated using mice of the DBA/1J strain, while aptamers were obtained by means of an in vitro selection method called SELEX. The analytical characteristics of the developed receptors were studied by ELISA-like assays, as well as cytochemistry on positive and negative cell lines for the protein of interest.

RESULTS

A total of 44 potential aptamers were identified. After a first bioinformatic screening, 9 candidates were chosen for evaluating their binding affinity in vitro. Two of them showed dissociation constants in the nanomolar range. One of the aptamers also showed specific staining of cells positive for the marker protein, as did one of the generated antibody clones.

CONCLUSIONS

The newly developed receptors have shown a great potential in the study of PDAC. However, their diagnostic and therapeutic usefulness requires a more in-depth evaluation, currently in progress.

ACKNOWLEDGEMENTS

This research was funded by the Spanish Government (RTI-2018-095756-B-I00) and Principado de Asturias Government (IDI2018-000217), co-financed by FEDER funds. R.L.G. thanks the Spanish Government for a predoctoral FPU fellowship (FPU16/05670).
THE MOST REALISTIC SURGICAL SIMULATION MODEL TO GAIN SKILLS IN LAPAROSCOPIC SURGERY IS THE CADAVERIC MODEL THIEL, ACCORDING TO OPINIONS OF DIFFERENT SPECIALIST SURGEONS
Authors: Soler Silva A , Sanchís López A , Sánchez Guillén L , Triguero Cánovas D , López Rodríguez Arias F , Aranaz Ostáriz V , Alcaide Quirós M J , Arroyo Sebastián A
Published: May 2021

INTRODUCTION

Laparoscopic procedures are still a challenge for the surgeon residents and young surgeon physicians. Different learning systems have been used without achieving a realism faithful to the lived in the operation room. All existing surgical simulation systems should be compared, with the aim of identifying the most realistic of them, for improving the surgical learning.

MATERIAL AND METHODS

An 18-item survey was sent to different specialized surgeons (general surgeons, gynecologists and urologists) who participated in international postgraduate laparoscopic surgery courses on cadavers embalmed by Thiel method. Participants were asked to the differences and improving skills in each surgical procedure, about the different surgical simulation models that the participants had already used. Surgeons were asked if they would recommend doing it during residency to improve their confidence in the operating room.

RESULTS

Attendees (n = 104) had a response rate of 92% (96 replies). The 91.8% surgeons recognized that Thiel model was more realistic than others simulation methods. The 97.9 % of respondents believed that had improved their surgical skills. Globally, 96.9% (93) of the participants surveyed recommended the conducting of these courses with Thiel cadavers to different colleagues of other specialties as a reliable simulation measure during the residency period.

CONCLUSIONS

Participants in the laparoscopic surgery course on the cadaver Thiel recognized that this is more realistic surgical simulation model than conventional models, one of the best ways to gain confidence and improve laparoscopic skills in operation room for inexperienced surgeons.
SPLENIC ANGIOGRAPHIC EMBOLIZATION IN IV AND V-GRADE SPLENIC INJURIES. DOES IT WORK? OUR EXPERIENCE ON THE MANAGEMENT OF SPLENIC INJURIES IN THE LAST 14 YEARS
Authors: Lucas Guerrero V , Montmany S , Rebasa P , Luna A , Navarro S
Published: May 2021

INTRODUCTION

Spleen is frequently damaged in abdominal trauma. Patients with splenic injury with hemodynamic instability, peritonism signs or other surgical injuries need emergent surgery. Hemodynamically stable patients are treated conservatively. Splenic embolization is indicated in injuries with blush, pseudoaneurysms or arteriovenous fistulas. It is unclear its indication in IV and V-grade splenic injuries without contrast extravasation.

Our hypothesis is that IV and V-grade splenic injuries embolization decreases conservative treatment failure.

MATERIAL AND METHODS

Retrospective observational study, including all patients with blunt splenic injuries, prospectively included in our registry of polytraumatic patients (>16 years) since 2006.

RESULTS

One hundred and seventy patients have been included since 2006. In 2006-2013, when splenic injuries with active bleeding, pseudoaneurysms or arteriovenous fistulas were embolized, 94 patients were included. 37,2% required surgery and 62,8% conservative treatment. Splenic embolization was performed in 17% of patients who were treated conservatively. Conservative treatment failure was 16,9%: 10 cases out of those who underwent medical treatment (4 required embolization and 6 needed surgery).

From 2014 to the present, when IV and V-grade injuries were included in the indications for embolization, 76 patients have been included. 38,2% required surgery and 61,8% were treated conservatively (40,4% were embolized and the rest were treated medically). One case (3,6%) of those treated medically and another (5,3%) of those embolized failed. Overall failure of conservative treatment was 4,3%.

CONCLUSION

Embolization of IV and V-grade splenic injuries decreases conservative treatment failure from 16,9% to 4,3%.
LONG-TERM OUTCOMES OF TRANSANAL TOTAL MESORECTAL EXCISION FOR RECTAL CANCER
Authors: Labalde Martínez M , Vivas Lopez A , Ocaña Jimenez J , García Villar O , Nevado García C , Narvaez Chavez C , García Borda F J , Ferrero Herrero E
Published: May 2021

INTRODUCTION

Transanal total mesorectal excision (TaTME) for rectal cancer offers a better vision of the dissection planes and facilitates the distal transection of the rectum. The aim of this study was to compare functional outcomes, local recurrence rate y 2-years overall survival and disease free survival rates of TaTME and laparoscopic total mesorectal excision (LPC TME).

MATERIAL AND METHODS

From December 2016 to October 2018, 50 patients (36 males and 14 females) with low rectal cancer and an age of 67 (55.7-75.2) years underwent TME (20 TaTME and 30 LPCTME).

RESULTS

Clinical features and quality indicators for rectal cancer surgery were similar in both groups. After a median follow-up of 35 (30-40) months, low anterior resection syndrome rate was 14% (15% vs 13%, p = 0.043), fecal incontinence rate was 8% (15% vs 3%, p = 0.017) and sexual dysfunction was 8% (15% vs 3%, p = 0.017). Systemic recurrence rate was 10% (15% vs 6%, p = 0.377). One patient presented local recurrence 2 years after TATME. 2-years overall survival rate was 98% (95% vs 100%, p = 0.400) and 2-years disease free survival rate was 90 % (85% vs 93%, p = 0.377).

CONCLUSION

Although 2-years overall survival and disease free survival rates were similar in TaTME and LPC TME group, functional outcomes were worse after TATME in our study.
PREVENTION OF INCISIONAL HERNIA AFTER MIDLINE LAPAROTOMY WITH MODIFICATION OF CLOSURE TECHNIQUE: SYSTEMATIC REVIEW AND META ANALYSIS
Authors: Lozada Hernández E E , Hernández Bonilla J P , Hinojosa Ugarte D
Published: May 2021

INTRODUCTION

Incisional hernia is the main complication after laparotomy, the prevention of this is currently aimed at preoperative rehabilitation, modification of the closure technique and the use of prophylactic mesh. The objective of the study was to measure the effectiveness of the modification in the laparotomy closure technique to reduce the incidence of incisional hernia.

MATERIAL AND METHODS.

A systematic review and meta-analysis were carried out following the PRISMA guidelines. The first objective was to determine the incidence of incisional hernia at one year of follow-up, comparing the modification in the closure technique with the usual closure. The secondary objective was to determine the difference in wound dehiscence and surgical site infection between these two groups. Only clinical trials were included and the random effects method was used for their analysis.

RESULTS

Seven clinical trials were included, comparing 1612 patients, the incidence of incisional hernia was significantly lower in the surgical technique modification group OR 0.55 (95% CI 0.38-79). Efficacy to reduce the incidence of wound dehiscence was also analyzed without finding a difference between the two groups OR 0.58 (95% CI 0.27-1.21). There was no statistically significant difference between both groups when comparing seroma hematoma and surgical site infection.

CONCLUSIONS

The modification in the laparotomy closure technique reduces the incidence of incisional hernia. However, when analyzing globally, only the Small bites and Reinforced tension line techniques contributed to this result.
IS EMERGENCY CHOLECISTOSTOMY STILL VALID IN THE MANAGEMENT OF ACUTE CHOLECYSTITIS? ANALYSIS OF OUR EXPERIENCE IN A SERIES OF 145 PATIENTS
Authors: Pujante Menchón M , Mella Laborde M , Rius Acebes l , Aparicio Navarro J , Morales Calderón M , Compañ Rosique A F
Published: May 2021

INTRODUCTION

Laparoscopic cholecystectomy may not be suited in elderly patients with comorbidities. Our objective is to evaluate whether our indication for cholecystostomy is in accordance with the 2018 Tokio Guidelines and to determine the clinical-epidemiological and analytical characteristics as well as the clinical results depending on the treatment (surgical, conservative or cholecystostomy).

MATERIAL AND METHODS

Retrospective observational study with patients diagnosed with acute cholecystitis between the 25/01/2019 and the 13/03/2020.

RESULTS

Out of 145 patients, 87 (60%) underwent cholecystectomy (average age 63 years), 47 (32,4%) treated conservatively (74,8) and 11 (7,6%) by cholecystostomy (85,8). The multivariate analysis showed that suffering from cardio and cerebrovascular diseases, CKD, taking anticoagulants and altered levels of creatinine, Quick or CRP, multiplies by 5.2, 6.4, 10.9, 4.6, 1.2 and 1.1 the probability of cholecystostomy versus cholecystectomy (p < 0,005). Both the time of admission and of antibiotic treatment was longer in the cholecystostomy group (15.2 and 11.5 days) compared to conservative (7 and 9) and surgical (5.3 and 5.8) (p = 0,000 and p = 0,011). Only one patient in the cholecystostomy group underwent subsequent surgery compared to 50% in the conservative group. The mortality rate did no differ. Out of 11 cholecystostomies, 6 met the Tokio Guidelines criteria.

CONCLUSIONS

1. Patients undergoing cholecystostomy are older, multipathological and present greater systemic involvement (KD, coagulopathy and elevated APR). They require a longer hospital stay and duration of antibiotic treatment.

2. 54,54% of the cholecystostomies performed were adapted to the 2018 Tokio Guidelines.

3. Conservative treatment means higher long-term complication rates.
A NOVEL EXTENSIVE EX-VIVO OCT DATABASE FROM MURINE MODELS OF COLORECTAL CANCER
Authors: Bote J , Ortega-Morán J F , Saratxaga C L , Pagador B , Picón A , Terradillos E , Moreno-Lobato B , Sánchez-Margallo F M
Published: May 2021

INTRODUCTION

New non-invasive technologies for improving early diagnosis of colorectal cancer (CRC) are demanded by clinicians. Optical Coherence Tomography (OCT) provides sub-surface structural information and offers diagnosis capabilities of colon polyps, further improved by machine learning methods. Databases of OCT images are necessary to facilitate algorithms development and testing.

MATERIALS AND METHODS

A database has been acquired from rat colonic samples with a Thorlabs OCT system with 930nm centre wavelength that provides 1.2KHz A-scan rate, 7μm axial resolution in air, 4μm lateral resolution, 1.7mm imaging depth in air, 6mm x 6mm FOV, and 107dB sensitivity. The colon from anaesthetised animals has been excised and samples have been extracted and preserved for ex-vivo analysis with the OCT equipment.

RESULTS

This database consists of OCT 3D volumes (C-scans) and 2D images (B-scans) of murine samples from: 1) healthy tissue, for ground-truth comparison (18 samples; 66 C-scans; 17,478 B-scans); 2) hyperplastic polyps, obtained from an induced colorectal hyperplastic murine model (47 samples; 153 C-scans; 42,450 B-scans); 3) neoplastic polyps (adenomatous and adenocarcinomatous), obtained from clinically validated Pirc F344/NTac-Apcam1137 rat model (232 samples; 564 C-scans; 158,557 B-scans); and 4) unknown tissue (polyp adjacent, presumably healthy) (98 samples; 157 C-scans; 42,070 B-scans).

CONCLUSIONS

A novel extensive ex-vivo OCT database of murine CRC model has been obtained and will be openly published for the research community. It can be used for classification/segmentation machine learning methods, for correlation between OCT features and histopathological structures, and for developing new non-invasive in-situ methods of diagnosis of colorectal cancer.