bluuebunny/crossref_metadata_2025 huggingface dataset:
Calculation and assessment of measures of the residual operating life of non-restorable items
Authors: Sadykhov G S , Kudryavtseva S S
Published: May 2021

The widespread use of cutting-edge components in the composition of non-restorable items has made it difficult to assess their reliability at the stages of designing and production. Therefore, items with underestimated values of the assigned (warranted) operating life are put into operation. By now, the service life of such items has reached the assigned limits, the items still maintaining a fairly high dependability rate. Thus, there has been a problem of extending the service life beyond the originally assigned rates. As originally assigned rates are determined by such measures as the mean operating life and gamma-percentile operating life, the non-restorable item’s life margin is determined as related to these rates by means of measures of the residual operating life, namely the mean residual operating life and gamma-percentile residual operating life. The mean residual operating life and gamma-percentile residual operating life are determined in this paper, to calculate the extendable service life. For these measures, we have derived calculation formulas and assessments which make it possible to determine the extended service life. In addition, for these measures, calculation formulas and assessments are obtained for non-restorable items whose margin allocation is distributed exponentially and uniformly. The paper examines the issues of attainability of the obtained assessments and the conditions of their attainability; also, the influence of failure rate monotonic change on the assessments is analyzed.
Analysis of errors in measuring displacement by a laser interferometer used as a feedback sensor precision lathe module feed drive
Authors: Ignatiev A A , Sigitov E A , Dobryakov V A , Ignatiev S A , Kazinsky A A , Nasad T G , Bokova L G
Published: May 2021

The article considers the structure of errors in measuring the displacement by a laser interferometer used as a feedback sensor for the feed drive of a turning module, and the conditions for their minimization to ensure precision machining of parts.
Digital traceability of measuring information
Authors: Zhirnova E A , Kulakova N S , Kuzmich R I , Yakimova L D , Kashapova N R
Published: May 2021

The issues of improving the quality of measurements on the basis of ensuring digital traceability of measuring information for measuring the volumetric flow rate of liquid on the example of water meters are investigated. The main technical and metrological characteristics of portable calibration facilities were considered. Comparative analysis of portable installations by differential and complex methods was carried out. New requirements for measuring equipment are substantiated. Based on the use of information technology, a model for ensuring the traceability of measuring information when checking water meters was developed.
Multi-objective Optimization of Intake Pipe and Valve Timing Based on Improved NSGA-II
Authors: Wei Sihang
Published: May 2021

The current research is based on a high-speed gasoline engine. The influence of intake pipe structural parameters and valve timing on engine’s performance was analysed by establishing thermodynamic model through software GT-Power. Full factorial experimental design was adopted and moving least squares method to establish response surface model at the full-load speed of 5500 r/min. Multi-objective optimization is carried out with genetic algorithm to solve Pareto frontier curve of economic and dynamic performance. The optimization effect by simulation was verified afterwards. The optimization can serve as guidance to determine valve timing of the fully variable valve and intake pipe. Optimization method proposed to this paper provides control parameters and theoretical basis for fully variable valve and intake pipe, reduces experimental workload and improves development efficiency.
Research and Application of Attitude Control and Stability Adjustment Technology for Underwater Robot Platform
Authors: Shi Hankun , Wang Xuelin , Zhang Wei
Published: May 2021

This research is mainly aimed at the difficulty in maintaining the stability of the position and posture of underwater visual equipment, and it is unable to provide reliable images for underwater search and salvage rescue operations. Investigating the existing mature technology and scheme, combined with the characteristics of the underwater operation of the visual equipment and based on the comprehensive analysis, a set of motion attitude stability analysis theory suitable for the underwater platform is proposed. Combined with various control theories, the motion control equations of underwater robots are established, and the optimal control method is designed. The control method is verified by computer simulation.The research results of the project can provide a reliable technical support and decision-making means for underwater search and salvage work, improve the automation level of underwater operations, reduce the difficulty of underwater operations, and improve the comprehensive response capability and technical level of deepwater search and rescue salvage levels.
An evaluation of Lidar-based 2D SLAM techniques with an exploration mode
Authors: Fan X , Wang Y , Zhang Z
Published: May 2021

SLAM is a fundamental problem in robotic field and there have been many techniques on it. It is necessary to give an insight on weakness and strength of these techniques specific to the intended final application. This paper presents a study of three most common laser-based 2D SLAM techniques: Gmapping, KartoSLAM and Cartographer. Each technique was applied to construct maps combined with autonomous exploration. All the approaches have been evaluated and compared in terms of inaccuracy of constructed maps against the ground truth. In order to draw conclusions on the performance of the tested techniques, a metrics of average distance to the nearest neighbor (ADNN) was applied. Moreover, the computational load of each technique is examined.
Future RPC developments
Authors: Cardarelli R.
Published: May 2021

The Resistive Plate Chamber detectors (RPC) proposed in the
'80s had time resolution of the order of ns, the spatial resolution
of the order of cm and counting capability of tens of
Hz/cm2. These detectors underwent since then a great
improvement in their performances. The improvement in counting
capability was obtained decreasing the average counting charge
thanks to a very high-performance front-end, which made it possible
to switch from the streamer discharge to the avalanche discharge
regime. The improvement in time resolution was achieved by
decreasing the thickness of the gas gap (MultiGap-RPCs) or
increasing the gas pressure (Pestov-RPCs). The improvement in
spatial resolution was obtained by measuring the position with the
charge weighted centre method by means of a very low noise analogic
electronics. In this paper, we suggest the possibility of creating
cylindrical RPCs called RCCs (Resistive Cylindric Chambers). We
discuss the advantages and disadvantages of the cylindrical
configuration, which could allow to obtain high temporal resolution
with a single thick pressurized gas-gap. Very preliminary results
were obtained with a RCC prototype. Possible application in future
experiments are discussed.
Finite element simulation and experimental verification of quasi-static compression properties for 3D spacer fabric/hollow microspheres reinforced three phase composites
Authors: Yu Lingjie , He Xiaoyi , Liang Fanchao , Meng Jiaguang , Fu Sida , Zhi Chao , Zhang Yuming , Sun Fengxin
Published: May 2021

To enhance the compressive properties of syntactic foams, a new type of ternary composite named 3D spacer fabric/hollow microspheres reinforced composite (3DSMRC) was designed by adding warp-knitted space fabric (WKSF) into traditional syntactic foam. In order deeply understand the meso-mechanical properties of 3DSMRC composites, the compression tests of 3DSMRC were carried out and the quasi-static compression finite element models were established based on COMSOL Multiphysics. The results show that the compression properties of 3DSMRC were obviously controlled by structures of WKSF. To be specific, the 3DSMRC composites with more spacer yarns per unit area could withstand higher critical load, and with denser surface layers and larger spacer yarns inclination-angle could gain better compression capacities. Meanwhile, different types of microspheres also had important impact on the compression capacities of specimens, which could be improved by using smaller radius ratio (higher strength) microspheres. In addition, the finite element model can accurately reproduce the compression process and stress-strain curves of representative 3DSMRC samples, and then accurately simulate the values of compressive modulus and yield strength. The simulation and experimental studies of 3DSMRC can help to obtain a better and deeper understanding of the compression properties of this new type of composite, and finally provide a useful theoretical reference for the optimization design of 3DSMRC.
Backscatter factors calculation for intraoral dental radiology
Authors: Paixão Lucas , Oliveira Bruno B , Vieira Leandro A
Published: May 2021

The dosimetry of intraoral radiography procedures is of great interest since dental examinations are among the most numerous radiological procedures. Usually, the surveys are performed using measurements free in air. The entrance surface air kerma (K

e
) can be estimated from measurements of incident air kerma and the use of backscatter factors (BSF). The purpose of this work is to calculate BSF values suitable for intraoral radiography. In addition to specific intraoral radiography, a comprehensive reassessment of internationally recommended BSF values was performed through Monte Carlo simulations. Moreover, the K

e
was estimated using the calculated BSF values for a sample of 44 intraoral radiography systems. The interpolation of intraoral radiography BSF values from reference data can lead to an overestimation of up to 10% and 6% in comparison with the values calculated in this work for monoenergetic photons and x-ray spectra, respectively. Such discrepancy may be relevant when defining diagnostic reference levels (DRLs) or performing quality control tests. The calculations for a sample of 44 intraoral radiography systems showed that the majority of the equipment operates with an entrance surface air kerma higher than 3.5 mGy. In the case of adopting a single value to estimate K

e
, the use of BSF equal to 1.2 results in less dispersion compared to calculated values in this work and the use of 1.1 can underestimate K

e
values up to 12%.
Methods used to attribute costs avoided from pharmacist interventions in acute care: A scoping review
Authors: Narayan Sujita W , Abraham Ivo , Erstad Brian L , Haas Curtis E , Sanders Arthur , Patanwala Asad E
Published: May 2021

Purpose

Cost-avoidance studies are common in pharmacy practice literature. This scoping review summarizes, critiques, and identifies current limitations of the methods that have been used to determine cost avoidance associated with pharmacists’ interventions in acute care settings.

Methods

An Embase and MEDLINE search was conducted to identify studies that estimated cost avoidance from pharmacist interventions in acute care settings. We included studies with human participants and articles published in English from July 2010 to January 2021, with the intent of summarizing the evidence most relevant to contemporary practice.

Results

The database search retrieved 129 articles, of which 39 were included. Among these publications, less than half (18 of 39) mentioned whether the researchers assigned a probability for the occurrence of a harmful consequence in the absence of an intervention; thus, a 100% probability of a harmful consequence was assumed. Eleven of the 39 articles identified the specific harm that would occur in the absence of intervention. No clear methods of estimating cost avoidance could be identified for 7 studies. Among all 39 included articles, only 1 attributed both a probability to the potential harm and identified the cost specific to that harm.

Conclusion

Cost-avoidance studies of pharmacists’ interventions in acute care settings over the last decade have common flaws and provide estimates that are likely to be inflated. There is a need for guidance on consistent methodology for such investigations for reporting of results and to confirm the validity of their economic implications.
The Impact of the Coronavirus Lockdown on Domestic Violence
Authors: McCrary Justin , Sanga Sarath
Published: May 2021

We use 911 call records and mobile device location data to study the impact of the coronavirus lockdown on domestic violence. The percent of people at home sharply increased at all hours, and nearly doubled during regular working hours, from 45% to 85%. Domestic violence increased 12% on average and 20% during working hours. Using neighborhood-level identifiers, we show that the rate of first-time abuse likely increased even more: 16% on average and 23% during working hours. Our results contribute to an urgent need to quantify the physical and psychological burdens of prolonged lockdown policies.
Large-Volume Autologous Fat Grafting to the Breast
Authors: Nahabedian Maurice Y
Published: May 2021

Autologous fat grafting in the setting of breast augmentation and reconstruction has become globally accepted and routinely performed. There is general consensus that small-volume grafting is reproducible and predictable; however, large-volume fat grafting (>100 mL) is less predictable and is not as commonly performed. The aim of this article was to review outcomes following large-volume and megavolume fat grafting in the setting of breast augmentation and reconstruction.

Level of Evidence: 4
Facial Rejuvenation With Fat Grafting and Fillers
Authors: Crowley J Sarah , Kream Elizabeth , Fabi Sabrina , Cohen Steven R
Published: May 2021

Facial rejuvenation requires a multi-modality approach to address the sun damage, volume loss, and thinning of skin that occurs with aging. With age, the collagen fibrils that provide strength become fragmented and fibroblasts connections become weak, leading to skin laxity and loss of youthful skin. Fillers can lead to a more youthful appearance by providing volumetric support. Synthetic fillers such as hyaluronic acid products, calcium hydroxyapatite, polylactic acid, and polymethylmethacralate have bio-stimulatory affects, ranging from small effects on fibroblast production to prolonged stimulatory effects on dermal thickness and blood supply. Fat grafting is also an ideal technique for facial rejuvenation because it is readily available, natural, and has regenerative effects. This review describes a new technique of fat grafting for the face called Injectable Tissue Replacement and Regeneration that specifically addresses the different anatomic compartments of the face with volume loss. With this brief review, we aim to evaluate the currents trends of fat grafting and fillers in the management of facial rejuvenation, including the cellular changes that occur with facial aging, the bio-stimulatory effects of fillers, and the anatomic replacement of tissue with fat grafting.

>Level of Evidence: 4
Surgical Decision Making in Autologous Fat Grafting: An Evidence-Based Review of Techniques to Maximize Fat Survival
Authors: Nemir Stephanie , Hanson Summer E , Chu Carrie K
Published: May 2021

Autologous fat grafting is an important tool in plastic surgery and is widely used for a variety of applications, both aesthetic and reconstructive. Despite an ever-increasing list of indications and extensive research over many years into improving outcomes, fat grafting remains plagued by incomplete and often unpredictable graft survival. Decisions made at each stage of surgery can potentially contribute to ultimate success, including donor site selection and preparation, fat harvest, processing, and purification of lipoaspirate, recipient site preparation, and delivery of harvested fat to the recipient site. In this review, we examine the evidence for and against proposed techniques at each stage of fat grafting. Areas of consensus identified include use of larger harvesting and grafting cannulas and slow injection speeds to limit cell damage due to shearing forces, grafting techniques emphasizing dispersion of fat throughout the tissue with avoidance of graft pooling, and minimizing exposure of the lipoaspirate to the environment during processing. Safety considerations include use of blunt-tipped needles or cannulas to avoid inadvertent intravascular injection as well as awareness of cannula position and avoidance of danger zones such as the subgluteal venous plexus. We believe that using the evidence to guide surgical decision-making is the key to maximizing fat grafting success.

Level of Evidence: 4
TECHNOLOGICAL BARRIERS OF LATINAMERICAN SURGICAL TRAINING CENTERS IN TIMES OF PANDEMIC: EXPERIENCES IN LOW RESOURCE ENVIRONMENTS
Authors: Reyes Monasterio A R , Cabrera Vargas L F , Reyes Herrera T , Acevedo Parrales J D
Published: May 2021

INTRODUCTION

In 2020, the SARS-CoV-2 / COVID-19 pandemic merited the reorganization of health institutions. It was necessary to suspend a large number of elective surgical procedures. For this reason, many surgical programs adopted new education measures such as simulation and virtual meetings. However, the reality in low- and middle-income countries is very different; so these initiatives could be challenging.

MATERIAL AND METHODS

It was an observational, descriptive, cross-sectional study. During the period from March 1 to December 31, 2020. 4 Latin American countries (Colombia, Mexico, Nicaragua and Venezuela) with a representative for each country. A survey was conducted in general surgery residents in order to assess the surgical education modalities used by training institutions to adapt the challenges of the SARS-CoV-2 / COVID-19 pandemic.

RESULTS

63 residents were evaluated. 32% dońt have internet access from home. 44% dońt have access to the internet in their training centers. 52% of residents deny using any social media to support the learning process. 90% have access to a personal smart device. 79% dońt have access to any simulation system to complement their training.

CONCLUSION

The internet access, the use of social media and simulation continues to be barriers to the learning process in times of pandemic in Latin American surgical residents.
3-D TECHNOLOGY & PEDIATRIC SURGERY: IBERO-AMERICAN SURVEY
Authors: Siles Hinojosa A , Roldón Golet M , Zabala Travers S , Hernández del Arco S
Published: May 2021

INTRODUCTION

The aim of this study is to evaluate the status and difficulty of 3-D technology implantation in the Ibero-American pediatric surgical field and to assess the opinion of medical professionals.

MATERIAL AND METHODS

Descriptive study of the results of an online survey conducted through google forms platform.

RESULTS

217 physicians from 15 countries answered the survey: 72.8% surgeons, 14.3% radiologists and others (12.9%). The majority (59%) do not have 3-D technology. Among those who used it (35.9%), 32.1% have worked with 3-D printing, 22.9% in virtual surgical planning and 15.6% with design and printing of customized surgical guides. Only 14.3% of the respondents received specific training; the majority know the technology through conversations with colleagues (39.2%) and attendance at medical conferences (45.6%). According to the pediatric surgeons who answered the survey, the areas that could benefit most from the use of 3-D are oncological surgery (56.4%), thoracic (49.5%) and hepatobiliary (42.7%). Lack of financial support (67%), ignorance (59.6%) and lack of human resources (46.8%) are considered the main difficulties of implantation. Most of the respondents agree that 3-D anatomical models have a positive impact on patient's ability to understand the disease (87.5%) and the risks of the surgical procedure (88%).

CONCLUSION

The implantation of 3-D technology in the Ibero-American pediatric surgical field is still limited and its causes are multiple. Despite this, professionals consider that this technological inclusion would have a positive impact on their clinical practice.
RESULTS OF LUNG TRANSPLANTATION ASSISTED WITH EXTRACORPOREAL MEMBRANE OXYGENATOR (ECMO)
Authors: Burgos Lázaro R J , Burgos Frías N , Rivas Oyarzabal J , Sánchez Calle A , Macías Sotuel A , Campo Cañaberal J L , Forteza Gil A , Varela Ugarte A
Published: May 2021

INTRODUCTION

According to the registry of the “International Society for Heart and Lung Transplantation” (ISHLT), 32% of lung transplants (Tx P) will require respiratory assistance in the perioperative period. The aim of the study is to compare the results of the Tx P that required ECMO, versus those that did not require respiratory assistance.

MATERIAL AND METHODS

Between January 2015 and December 31th 2018, 184 lung transplants were performed in the organ transplant unit. In 119 (64.7%) of the transplants, they did not need respiratory assistance and in 65 (35.3%) they required ECMO either intraoperatively and/or postoperatively. The indications for lung transplantation were: interstitial fibrosis 77 (41.8%), pulmonary emphysema 64 (34.7%), cystic fibrosis 28 (15.3%), others 15 (8.2%).

RESULTS

Patients with Mean Pulmonary Pressure (MPP) greater than 54 mmHg required assistance with ECMO during transplantation (p < 0.03). 83% of transplanted patients remained in NYHA grade I and grade II. Hospital mortality was 21/184 (11.4%); ECMO mortality 14/67 (20.9%) vs NO-ECMO mortality 6/117 (5.1%), significantly higher (p < 0.005 OR = 4.98). Survival and quality of life at 5 years were similar in both groups (p = 0.09).

CONCLUSIONS

ECMO has proven to be safe and effective in Tx P. Patients with PMP> 54 mmHg required ECMO (p < 0.03). After the hospital postoperative period, the quality of life and survival at five years were similar in both groups.
PERITONEAL DIALYSIS, A MEDICAL-SURGICAL COLLABORATION, DO WE OFFER QUALITY STANDARDS?
Authors: Llosa Pérez J , Michi Campos J L , Rodicio Miravalles J L , Astudillo Cortés E , Bande Fernández J , Rodríguez Suárez C , López-Negrete Cueto E , Granero Trancón J E
Published: May 2021

INTRODUCTION

Peritoneal dialysis is one of the renal replacement therapy options for patients with advanced chronic kidney disease. It provides an improvement in quality of life since it is practiced at home once a previous training has been completed, waiting for kidney transplant or if the patient is not a candidate for it.

MATERIAL AND METHODS

Between January 2014 and December 2017, an observational, descriptive, longitudinal and retrospective study was performed with 211 patients treated with peritoneal dialysis in a tertiary level hospital. In a 2-year follow-up, the complications, results and situation of peritoneal dialysis were analyzed, providing solutions for a better quality of patient care. Clinical and surgical variables were collected.

RESULTS

Survival of the first and second catheters was greater than 12 months in 79.5% and 86.2% of the patients, respectively. In the first 30 days after catheter placement, 4.7% of the patients had peritonitis. In no case was there visceral damage during surgery, nor was a reoperation required during the immediate postoperative period. Neither postoperative transfusions were needed nor were there leaks. The most important cause of end of technique (34.1%) was receiving a kidney transplant.

CONCLUSIONS

The peritoneal dialysis technique can be considered a good medical-surgical collaboration, since, in addition to complying with the established quality standards regarding this treatment, it is self-sufficient and effective as a renal replacement treatment in patients with advanced chronic kidney disease.
EFFECT OF TEMPERATURE ON THE MECHANICAL BEHAVIOR OF THE HUMAN AORTA AND CAROTID ARTERIES
Authors: Burgos Frías N , Burgos Lázaro R J , Rivas Oyarzabal J , Ospina Mosquera V , Rojo Pérez F , Atienza Riera J M , Forteza Gil A , Guinea Tortuero G
Published: May 2021

INTRODUCTION

Temperature affects the mechanical behavior of the arteries, a fact that intervenes in their function, both in physiology and in pathological states. The aim of the study is to analyze the mechanical response in the arteries (aorta and carotids) to changes in temperature.

MATERIAL AND METHODS

The thermo-mechanical behavior of human arteries (26 primitive carotids and 26 thoracic aortas) from cadaveric organ donors has been studied. The tests were carried out in a passive state, without electrical or chemical activation of the vessels. Pressurization tests were carried out at 4 different temperatures (17, 27, 37 and 42ºC) correlating internal pressure-external diameter of the vessels. The thermo-mechanical analysis was evaluated using the pressure-diameter curves at different temperatures, for this the coefficient of thermal expansion (α = (ΔD / D) / ΔT) and the Hayashi stiffness (β), exponential equation (Pressure / Diameter ratio).

RESULTS

The effect of temperature on arterial behavior is maximum when the curves refer to the initial diameter of the vessel at 0 mmHg for each temperature. At low pressures, the coefficient of dilation is negative, while above a certain threshold pressure (different for each type of artery), the coefficient of dilation becomes positive.

CONCLUSIONS

The stiffness of the vessels is manifested in the slope of the pressure-diameter curves and decreases with increasing temperature. The coefficient of thermal expansion is a function of the internal pressure to which the arteries are subjected.
TUNNELED LAPAROSCOPIC PERITONEAL DIALYSIS CATHETER AS A RESOURCE TECHNIQUE IN PERITONEAL DIALYSIS
Authors: Díaz Vico T , Rodicio Miravalles J L , Suárez Sánchez A , García Munar M , Carrasco Aguilera B , del Val Ruiz P , Amoza Pais S , Sanz Álvarez L M
Published: May 2021

INTRODUCTION

Surgical approach to peritoneal dialysis (PD) catheters is the main step in achieving successful PD therapy. It is important to conduct a simple and safe procedure, with adequate visualization of the path and location of the catheter, to avoid discontinuation of PD. The tunneled laparoscopic PD catheter (TLPDC) is a reliable surgical alternative in patients who are candidates for PD.

MATERIAL AND METHODS

This is a retrospective and descriptive study that includes all the patients in whom TLPDC was placed from October 2019 to January 2021. The objective is to know the rate of functioning and evaluate the complications derived from the procedure.

RESULTS

TLPDC was placed in 7 patients with a mean age of 51.4 (7.7) years and a mean BMI of 26.6 (8.0) kg/m2. Rescue therapy was considered in 6 (85.7%) patients, after removal of a previous PD catheter. There was no case (0.0%) of displacement, being the adequate functioning rate of 85.7%. One (14.3%) case of bacterial peritonitis was diagnosed, resolved with conservative management, and early TLPDC dysfunction in another (14.3%) case, requiring laparoscopic revision on the eleventh postoperative day and its repositioning, with current suspicion of encapsulating peritonitis.

CONCLUSIONS

The TLPDC approach is a safe and simple technique, avoiding displacement of the catheter and, thus, a higher success rate. However, as a counterpoint, it requires general anesthesia to be performed. Furthermore, an adequate selection of a suitable candidate for PD is necessary to ensure the success of the procedure.
RESULTS OF HYPERTHERMIC INTRAPERITONEAL CHEMOTHERAPY AND CYTOREDUCTIVE SURGERY FOR PERITONEAL CARCINOMATOSIS OF COLORECTAL ORIGIN
Authors: Merayo Alvarez M , Turienzo Santos E , García Munar M , Cifrián Canales I , Rodicio Miravalles J L , Moreno Gijón M , Sanz Alvarez L
Published: May 2021

INTRODUCTION

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is supported by clinical practice and published series as a fundamental treatment for increasing survival of selected patients with colorectal peritoneal carcinomatosis. The results were evaluated since having implemented a peritoneal oncological surgery program five years ago.

MATERIAL AND METHODS

Descriptive analysis was conducted to patients who had been diagnosed with peritoneal carcinomatosis from May 2014 to December 2020. 36 out of 100 patients who had undergone surgery were included in the CRS and HIPEC assessment and 6 patients without HIPEC, were excluded.

RESULTS

The mean preoperative PCI was 7.81±6.61 accomplishing complete cytoreduction CC 0-CC-1 in the 36 cases. An average of 1.86±1.22 peritonectomies were performed. Among procedures, complete pelviperitonectomy (11 patients) and liver metastasis resection (6 patients) should be noticed. Complications were presented in 16 patients (8 patients over Clavien Dindo>III) and 6 required reinterventions due to hematoma (2) or anastomotic leak (2) mostly. The 4-year overall survival is 76.2% and the disease-free interval is 34 months within an average follow-up of 23 months.

CONCLUSIONS

The overall survival and disease-free interval rates are above the standards. Currently, peritoneal carcinomatosis might be considered a curative disease. The multidisciplinary assessment allows selecting patients who will benefit from surgery.
INFLUENCE OF COVID-19 IN ACUTE APPENDICITIS
Authors: Arango Bravo A , Mateos Palacios C , Pérez Prudencio E , Soto Dopazo M , Nuño Iglesias C , Álvarez Laso C J , Sosa Rodríguez V
Published: May 2021

INTRODUCTION

The SARS-CoV-2 pandemic has altered daily medical practice in hospitals. A frequently intervened pathology is acute appendicitis, which could be affected by this situation.

MATERIAL AND METHODS

We propose a retrospective observational study on patients involved in our centre. They are divided into two groups, the preCOVID group with 123 patients surgically intervened between 15/03/19 and 31/12/19 and the postCOVID group with 101 patients surgically intervened between 15/03/20 and 31/12/20. We use T Student for quantitative variables and Chi2 for qualitative variables. p < 0.05 was considered statistically significant.

RESULTS

The preCOVID group, 54 males and 64 women. Average age 38.57. Average stay 3.33 days. There were 79 phlegmonous appendicitis, 27 necrotizing, 9 perforated and 8 plastron appendicitis.

The postCOVID group, 57 males and 44 women. Average age 41.12. Average stay 4.27 days. There were 49 phlegmonous appendicitis, 33 necrotizing, 11 perforated and 8 plastron appendicitis.

We observed statistically significant differences from time to intervention and intra-abdominal drainage placement, both being larger in the postCOVID group (p-0.038; p-0.037 respectively). We dońt found statistically significant differences in other variables.

CONCLUSIONS

Patients in the postCOVID group are surgically intervened later, probably motivated by the need to perform a PCR to discount SARS-CoV-2, previously to intervention. More drains are also placed in this group, probably because more acute appendicitis is involved in higher severity phases than in the preCOVID group although there areńt significant differences in this regard.
Phosphate binders in dialysis: better satisfied than sorry
Authors: Cozzolino Mario , Galassi Andrea , Ciceri Paola
Published: May 2021

High serum phosphate levels have been associated with increased morbidity and mortality in dialysis patients. Nephrologists routinely counteract the positive phosphate balance in dialysis patients through nutritional counselling, stronger phosphate removal by dialysis and prescription of phosphate binders. An individualized choice of phosphate binders is a desirable option to improve the poor adherence with these medications’ prescription that has been associated with hyperphosphataemia.
Primary laparoscopic fundoplication in selected patients with gastroesophageal reflux disease
Authors: Fuchs K H , Breithaupt W , Varga G , Babic B , Schulz T , Meining A
Published: May 2021

Background

Despite proton pump inhibitors being a powerful therapeutic tool, laparoscopic fundoplication (LF) has proven successful in the treatment of gastroesophageal reflux disease (GERD), through mechanical augmentation of a weak antireflux barrier and the advantages of minimally invasive access. A critical patient selection for LF, based on thorough preoperative assessment, is important for the management of GERD-patients. The purpose of this study is to provide an overview on the management of GERD-patients treated by primary LF in a specialized center and to illustrate the possible outcome after several years.

Methods

Patients were selected after going through diagnostic workup consisting of patient’s history and physical examination, upper gastrointestinal endoscopy, assessment of gastrointestinal Quality of Life Index, screening for somatoform disorders, functional assessment by esophageal manometry, (impedance)-24-hour-pH-monitoring, and selective radiographic studies. The indication for LF was based on EAES-guidelines. Either a floppy and short Nissen fundoplication was performed or a posterior Toupet-hemifundoplication was chosen. A long-term follow-up assessment was attempted after surgery.

Results

In total, n = 1131 patients were evaluated (603 males; 528 females; mean age; 48.3 years; and mean body mass index: 27). The mean duration between onset of symptoms and surgery was 8 years. Nissen: n = 873, Toupet: n = 258; conversion rateerativ: 0.5%; morbidity 4%, mortality: 1 (1131). Mean follow-up (n = 898; 79%): 5.6 years; pre/post-op results: esophagitis: 66%/12.1%; Gastrointestinal Quality of Life Index: median: 92/119; daily proton pump inhibitors-intake after surgery: 8%; and operative revisions 4.3%.

Conclusions

In conclusion, our data show that careful patient selection for laparoscopic fundoplication and well-established technical concepts of mechanical sphincter augmentation can provide satisfying results in the majority of patients with severe GERD.
Rhizosphere shotgun metagenomic analyses fail to show differences between ancestral and modern wheat genotypes grown under low fertilizer inputs
Authors: Quiza Liliana , Tremblay Julien , Greer Charles W , Hemmingsen Sean M , St-Arnaud Marc , Pozniak Curtis J , Yergeau Etienne
Published: May 2021

It is thought that modern wheat genotypes have lost their capacity to associate with soil microbes that would help them acquire nutrients from the soil. To test this hypothesis, ten ancestral and modern wheat genotypes were seeded in a field experiment under low fertilization conditions. The rhizosphere soil was collected, its DNA extracted and submitted to shotgun metagenomic sequencing. In contrast to our hypothesis, there was no significant difference in the global rhizosphere metagenomes of the different genotypes, and this held true when focusing the analyses on specific taxonomic or functional categories of genes. Some genes were significantly more abundant in the rhizosphere of one genotype or another, but they comprised only a small portion of the total genes identified and did not affect the global rhizosphere metagenomes. Our study shows for the first time that the rhizosphere metagenome of wheat is stable across a wide variety of genotypes when growing under nutrient poor conditions.
Quantitative interactions: the disease outcome of Botrytis cinerea across the plant kingdom
Authors: Caseys Celine , Shi Gongjun , Soltis Nicole , Gwinner Raoni , Corwin Jason , Atwell Susanna , Kliebenstein Daniel J
Published: May 2021

Botrytis cinerea is a fungal pathogen that causes necrotic disease on more than a thousand known hosts widely spread across the plant kingdom. How B. cinerea interacts with such extensive host diversity remains largely unknown. To address this question, we generated an infectivity matrix of 98 strains of B. cinerea on 90 genotypes representing eight host plants. This experimental infectivity matrix revealed that the disease outcome is largely explained by variations in either the host resistance or pathogen virulence. However, the specific interactions between host and pathogen account for 16% of the disease outcome. Furthermore, the disease outcomes cluster among genotypes of a species but are independent of the relatedness between hosts. When analyzing the host specificity and virulence of B. cinerea, generalist strains are predominant. In this fungal necrotroph, specialization may happen by a loss in virulence on most hosts rather than an increase of virulence on a specific host. To uncover the genetic architecture of Botrytis host specificity and virulence, a genome-wide association study (GWAS) was performed and revealed up to 1492 genes of interest. The genetic architecture of these traits is widespread across the B. cinerea genome. The complexity of the disease outcome might be explained by hundreds of functionally diverse genes putatively involved in adjusting the infection to diverse hosts.
Rapamycin Activates Mitophagy and Alleviates Cognitive and Synaptic Plasticity Deficits in a Mouse Model of Alzheimer’s Disease
Authors: Wang Hui , Fu Jingxuan , Xu Xinxin , Yang Zhuo , Zhang Tao
Published: May 2021

Alzheimer’s disease (AD) is a chronic neurodegenerative disease, which is characterized by cognitive and synaptic plasticity damage. Rapamycin is an activator of autophagy/mitophagy, which plays an important role in identifying and degrading damaged mitochondria. The aim of this study was to investigate the effect of rapamycin on cognitive and synaptic plasticity defects induced by AD, and further explore if the underlying mechanism was associated with mitophagy. The results show that rapamycin increases Parkin-mediated mitophagy and promotes fusion of mitophagosome and lysosome in the APP/PS1 mouse hippocampus. Rapamycin enhances learning and memory viability, synaptic plasticity, and the expression of synapse-related proteins, impedes cytochrome C-mediated apoptosis, decreases oxidative status, and recovers mitochondrial function in APP/PS1 mice. The data suggest that rapamycin effectively alleviates AD-like behaviors and synaptic plasticity deficits in APP/PS1 mice, which is associated with enhanced mitophagy. Our findings possibly uncover an important function of mitophagy in eliminating damaged mitochondria to attenuate AD-associated pathology.
Lifetime Prevalence of Intimate Partner Violence and Health-Related Outcomes among Transgender Adults Aged 50 and Older
Authors: Hillman Jennifer
Published: May 2021

Background and Objectives

Intimate partner violence (IPV) has been linked with poor health among young transgender adults, and cisgender lesbian, gay, bisexual (LGB), and heterosexual adults aged 50 years and older. The objective was to examine lifetime prevalence of IPV and its association with health, among transgender adults aged 50 and older. Consistent with the Gender Minority Stress Framework, any IPV was hypothesized to be associated with worse health.

Research Design and Methods

Responses from 3,462, transgender adults aged 50 and older from the 2015 U.S. Transgender Survey were assessed for lifetime IPV and type. Logistic regression analyses, adjusted for demographic characteristics, examined the association between any IPV and substance use, and mental and general health measures.

Results

57% of respondents reported any lifetime IPV, including transgender-specific (41%), physical (36%), psychological (29%), severe physical (24%), stalking (12%), and sexual (10%) abuse. Given any, compared to no, experience of IPV, the odds of having a disability (adjusted odds ratio [AOR] = 1.21, confidence interval [CI] = 1.00–1.46) and rating current health more negatively (AOR = 1.17, CI = 1.08–1.26); smoking (AOR = 1.31, CI = 1.08–1.58) and qualifying for screening for serious mental illness (AOR = 1.32, CI = 1.04–1.66) within the last month; and ever using drugs (AOR = 1.42, CI = 1.22–1.65) and attempting suicide (AOR = 1.98, CI = 1.66–2.46) were significantly higher; only binge drinking was unrelated to IPV.

Discussion and Implications

More than half of the respondents experienced IPV, with trans-specific IPV reported most commonly. Lifetime prevalence of any IPV was significantly associated with worse health. Recommendations include health surveillance that recognizes gender identity, and longitudinal study and routine screening of IPV, including trans-specific abuse, among transgender adults aged 50 and older.
Specialist versus Generalist at the Intraspecific Level: Functional Morphology and Substrate Preference of Mediodactylus kotschyi Geckos
Authors: Schwarz Rachel , Stark Gavin , Antonopolous Antonis , Itescu Yuval , Pafilis Panayiotis , Chapple David G , Meiri Shai
Published: May 2021

Synopsis

Populations of the same species occupying different microhabitats can either exhibit generalized traits across them or display intraspecific variability, adapting to each microhabitat in order to maximize performance. Intraspecific variability contributes to the generation of diversity, following selection and adaptation, and understanding such variability is important for comprehending how individuals choose their microhabitats. Compared with interspecific variability, however, intraspecific variability in functional morphology and its relationship with microhabitat preference and use have been relatively little studied. Here we examined whether populations of the gecko Mediodactylus kotschyi that differ in the substrates they occupy display habitat-specific behaviors and differing morphologies associated with functional adaptation to their microhabitats. We collected 207 geckos from under or on rocks or on trees from seven populations in Greece. On large islands individuals occupy both substrates; whereas small islets are devoid of trees and the geckos are restricted to rocks, while on the mainland they are only found on trees. We determined gecko substrate preferences in the laboratory, together with their clinging abilities to the different substrates. We measured their limbs, digits, and claws and assessed how these measurements relate to clinging ability. Geckos from all populations preferred the tree made available to them, but this preference was not statistically significant. Geckos from both large and small islands clung better to the tree than to the rock in the laboratory, while those from the mainland clung similarly to both substrates. Geckos collected from trees had longer manual digits and hind limbs. Geckos collected from large and small islands had taller (longer on the dorso-ventral axis; henceforth “deeper”) claws. Longer digits and deeper but shorter claws were associated with a better ability to cling to rocks. Our findings suggest that while M. kotschyi is potentially preferentially arboreal, due to the great variation and plasticity it possesses, it can successfully also exploit the habitats available on the smallest, treeless islets in the Aegean Sea. Our study suggests that the dichotomous use of generalist versus specialist in describing species’ habitat use is oversimplified, and we suggest the use of a generalist–specialist gradient instead.
Critical domain sizes of a discrete-map hybrid and reaction-diffusion model on hostile exterior domains
Authors: Fazly Mostafa
Published: May 2021

We study a hybrid impulsive reaction-diffusion equation composed with a discrete-time map in bounded domain $\varOmega $ in space dimension $n\in \mathbb N$. We assume that the exterior of domain is not lethal (not completely hostile) but hostile. We consider Robin boundary conditions which are used for mixed or reactive or semipermeable boundaries. Given geometry of the domain $\varOmega $, we establish critical domain sizes for the persistence and extinction of a species. Specifically, for habitats with the shape of $n$-hypercube and ball of fixed radius, we formulate the critical domain sizes depending on parameters of the model, including $h$, i.e. a measure of the hostility of the external (to $\varOmega $) environment. For a general habitat, called Lipschitz domains, we apply isoperimetric inequalities and variational methods to find the associated critical domain sizes. We also provide applications of the main results in marine reserve, terrestrial reserve and insect pest outbreaks.
Including Distorted Specimens in Allometric Studies: Linear Mixed Models Account for Deformation
Authors: Wynd B M , Uyeda J C , Nesbitt S J
Published: May 2021

Synopsis

Allometry—patterns of relative change in body parts—is a staple for examining how clades exhibit scaling patterns representative of evolutionary constraint on phenotype, or quantifying patterns of ontogenetic growth within a species. Reconstructing allometries from ontogenetic series is one of the few methods available to reconstruct growth in fossil specimens. However, many fossil specimens are deformed (twisted, flattened, and displaced bones) during fossilization, changing their original morphology in unpredictable and sometimes undecipherable ways. To mitigate against post burial changes, paleontologists typically remove clearly distorted measurements from analyses. However, this can potentially remove evidence of individual variation and limits the number of samples amenable to study, which can negatively impact allometric reconstructions. Ordinary least squares (OLS) regression and major axis regression are common methods for estimating allometry, but they assume constant levels of residual variation across specimens, which is unlikely to be true when including both distorted and undistorted specimens. Alternatively, a generalized linear mixed model (GLMM) can attribute additional variation in a model (e.g., fixed or random effects). We performed a simulation study based on an empirical analysis of the extinct cynodont, Exaeretodon argentinus, to test the efficacy of a GLMM on allometric data. We found that GLMMs estimate the allometry using a full dataset better than simply using only non-distorted data. We apply our approach on two empirical datasets, cranial measurements of actual specimens of E. argentinus (n = 16) and femoral measurements of the dinosaur Tawa hallae (n = 26). Taken together, our study suggests that a GLMM is better able to reconstruct patterns of allometry over an OLS in datasets comprised of extinct forms and should be standard protocol for anyone using distorted specimens.