bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulation of the stop points throughput capacity in urban public transport
Authors: Fadeev A I , Alhusseini S
Published: February 2021

The article considers the problem of determining the throughput capacity of bus lines, which is usually determined by the limited throughput capacity of stopping points. Currently, the throughput capacity of a stop point is usually defined as the inverse mathematical expectation of the average service time for one transportation vehicle. To account such factors as random disturbances in the transport process, appropriate correction coefficients are applied. However, it has not been proved that the considered coefficients provide acceptable results for practice in all cases. In this article, in order to study the throughput capacity, the work of a stopping point is described as a multi-channel single-phase queuing system (QS). An algorithm is proposed for simulating a public transport stopping point model based on the principle of consecutive submitting requests. The recommendations formulated for the throughput capacity regulation of stop points are illustrated by using an example of a specific stop point.
The optimization of the lateral motion control system of an unmanned aerial vehicle
Authors: Kramar V A , Kabanov A A
Published: February 2021

The article is devoted to the possibility of constructing an aircraft lateral motion control system only using the rudder; a mathematical model of such a system is obtained based on the structuring of an unmanned aerial vehicle model. The design of optimal lateral motion control of a UAV is carried out using the linear-quadratic optimization method in the complex domain for single-control systems. As an optimization criterion, a quadratic criterion in the form of restrictions on the control energy is used. Examples of system modeling are given.
Modeling of peat tractor semi-trailer motion
Authors: Mikhailov A V , Zhigulskaya A I , Kasakov YA
Published: February 2021

Wheeled tractor vehicles are used to transport peat from open cast mines to storage stockpiles or processing facilities. This paper analyzes dynamic stability and control of an articulate vehicle. A mathematical model of linear dynamics is demonstrated for deformed supporting base and a two-tier transport unit consisting of an AWD tractor and a two-axle trailer. The functions obtained from analysis of maneuverability of the transport unit may be used in studies of operational and technical properties of the vehicles as calculation formulas to determine the trajectories of its components when transporting peat materials in peat mines. This analytic approach provided understanding of the propulsion system of the tractor vehicle and grounds for subsequent computer modeling of the process.
Investigation of the dynamics of a small spacecraft elastic element temperature change under a temperature shock considering a penumbral section
Authors: Sedelnikov A V , Orlov D I , Leskova Yu D
Published: February 2021

In this paper, a study of the temperature shock of small technological spacecraft large elastic elements, considering the penumbral and shadow areas of its orbit, is carried out. A comparison of the dynamics changes in the temperature field of an elastic element with and without consideration of the penumbral section is presented. Conclusions are made about the significance of the penumbral section for modeling the dynamics of the small spacecraft under a temperature shock orbital motion in order to create favorable conditions for micro-accelerations for the successful implementation of gravitationally sensitive technological processes. The results of the work can be used in the small technological spacecraft design and the development of algorithms that reduce the negative impact of temperature shock on the micro-acceleration field of the small spacecraft inner environment.
Approximation of EMF spatial distribution near mobile phone in order to form a “virtual” antenna array
Authors: Pasternak Yu G , Negrobov V V , Ostankov A V , Fedorov S M , Ischenko E A , Razinkin K A , Antipov S A
Published: February 2021

Article describes the methods of approximation of electromagnetic field spatial distribution, which spatial samples are measured using an annular antenna array located near scatterer with a priori unknown geometry and material properties. As example, case of mobile phone located at user’s head were studied. The model of the human head and hand was simulated as a layered structure, the outer layer imitated the skin, and water was used as the inner filling. The study results show good performance of modified method of forming a “virtual” antenna array, which can significantly reduce the field approximation error, thereby making it possible to successfully predict the electromagnetic field phase structure at distances exceeding the radius of the used antenna array by three times. Proposed method can significantly increase the efficiency of subspace methods of direction finding and methods of adaptive signal processing in multichannel systems (in particular, the MIMO) due to the multiple increase in the number of virtual channels which are functionally equivalent to additional real channels, and also - increasing the electrical dimensions of the antenna system (“virtual” antenna array).
Analysis of the functioning of the orientation device to the Earth of a telecommunications space satellite
Authors: Petrov M N
Published: February 2021

This article presents the results of statistical observations of an operating communications spacecraft. The functioning of the orientation system to the Earth is considered. For ensure the reliability of communication between the satellite and ground stations, it is important to have a constant direction to the coverage area. For this, the spacecraft has an orientation system to the Earth. The orientation aims to create a reliable connection on the territory of the country of the spacecraft owner. The article examines the analysis of the operation of the satellite guidance system to the Earth using the example of a telecommunications communication satellite of the Republic of Kazakhstan. At the same time, the satellite orientation system to the Sun works in parallel to organize a stable and stable connection. The statistics of the operation of the orientation system to the Earth are presented. For this, the satellite has devices responsible for positioning – the orientation devices to the Earth. There are two given devices, namely, POZ-1 and POZ-2. The analysis of real statistics is given. The forecast of the system operation for the next nine years has been made.
Effect of electrode pressing force on the amount of energy supplied to interelectrode space in resistance projection welding with constant current welding machine
Authors: Yu Paliakou A
Published: February 2021

The paper describes the procedure for theoretical and experimental determination of the graphical regularity of the effect of the electrode pressing force on the amount of energy supplied to the interelectrode space when producing overlap joints of plates with equal thicknesses by using resistance projection welding. The regularity reflects a sufficiently strong connection between the parameters of the welding mode with the heat balance equation of the interelectrode space and the Joule-Lenz law.
A model for predicting the temperature of a machine tool structure by a neural network using the sliding window method
Authors: Pozevalkin V V , Polyakov A N
Published: February 2021

The paper studies a model for predicting the surface temperature of structural elements of a machine tool using artificial neural networks. A method of forming a training sample by the sliding window method for solving the problem of retrospective forecasting is presented. As applied to a neural network, the sliding window method is an algorithm for forming a training set from an initial set of experimental data necessary to build a forecasting model. Research was carried out for various types of neural networks, namely, generalized regression neural network, radial basis function network and feed forward network. Extrapolation was performed using multistep prediction, in which the predictive system uses the data obtained at the output of the neural network to predict subsequent values. The efficiency and practical suitability of neural network models for predicting the temperature of key heat sources located in certain areas of the machine structure was verified.
The method of aviation systems diagnostics according to the admissible level of non-failure operation probability
Authors: Sidnyaev N I , Butenko Iu I , Bolotova E E
Published: February 2021

The paper presents the methods of forecasting reliability of the created devices, design of devices with the given reliability and comparison of reliability of various aviation systems. Calculated relations at various types of redundancy in tests, prolongation of service life of blocks of aircraft, the basis of which is methodology of estimation of residual resource are resulted. The existing methods of reliability analysis are systematized and studied. The problems of uncertainty of information on input data at calculations by classical methods are stated. It is postulated that the principle of comparability of results of quantitative estimations of technical systems assumes the use of uniform composition of initial data for a certain reporting period of time, unity of generalized and private indicators used as well as unity of assumptions and limitations accepted. The application of general and elementary formulation of the state estimation of complex mechanisms with the use of diagnostic matrix and recognition theory to determine the state of technical objects is shown. Stages of the general process of object diagnostics are described, which consist in determination of parameter changes at influence on object elements and further processing of the obtained results using synthesis and analysis methods.
Mathematical model of a radial sliding bearing with a porous layer on its operating surface with a low-melting metal coating on shaft surface
Authors: Akhverdiev K S , Bolgova E A , Mukutadze M A , Vasilenko V V
Published: February 2021

The paper considers the steady flow of a liquid lubricant and a melt of a low-melting metal coating of the shaft surface, which have viscous rheological properties in the operating clearance of an endless radial sliding bearing, as well as in the body of the porous coating of the surface of bearing bush. In order to solve this problem, the authors used the equation of the movement of viscous lubricant for a thin layer, the equation of continuity and also the equation describing the radius of the molten contour of the fusible coating of the shaft surface, taking into account the rate of dissipation of mechanical energy. Having averaged the acceleration of the movement of the liquid lubricant in the operating clearance, the authors obtained the dependence for the contour of the molten coating of the shaft surface. As a result of the integration of the obtained dependence, the expression was found that allowed solving the function characterizing the contour of the molten surface of the coating by the method of successive approximations. Using the well-known method of finding an exact self-modal solution, the velocity field and pressure in the lubricating and porous layer, as well as the load capacity and friction force, were found. On the basis of the performed theoretical studies, the experimental study was carried out taking into account the parameters characterizing the melt of a low-melting metal coating, as well as a porous coating on the surface of the bearing bush and the rheological properties of a viscous lubricant. As a result, the original expression was obtained for the calculation of the load capacity of a radial bearing and the magnitude of the friction force in the range under the following loading conditions v=0.5÷3 m/s, σ=2÷7 MPa. The research results can be used in mechanical engineering, aircraft construction, instrument engineering, where the supply of lubricant is associated with great difficulties.
Automation of the procedure for assessing the quality of transport service for the population in the conditions of digitalization of the railway transportation system
Authors: Bulokhova T A , Olentsevich V A , Konyukhov V Yu , Lysenko D A
Published: February 2021

The Strategic Program for the Development of Railway Transport until 2030 focuses on the development of a customer-oriented approach as one of the conditions for the company’s competitiveness. The customer focus is one of the elements of anti-crisis management of transport systems, it provides additional opportunities, especially when the volume of traffic decreases, when it is necessary to fight for attracting customers. A customer-oriented approach is closely related to the quality of the organization of transport services for passengers, which is certainly impossible without the use of modern automated technologies. Thus, a modern passenger is characterized by mobility and the habit of being online, in connection with which the passenger infrastructure and rolling stock must be provided with equipment and software that allows the passenger to remain in the familiar information environment.
Automation of preproduction processes for high-precision small-sized parts on CNC machines
Authors: Karlina Yu I , Kargapoltsev S K , Gozbenko V E , Leonovich D S , Karlina A I
Published: February 2021

The theoretical basis of the processes of preparation for the production of high-precision small-sized parts of coaxial radio components on CNC machines allows you to supplement the existing CAD / CAE / CAM with fragments of algorithmizing. To integrate the stages of technological preparation for the production of high-precision small-sized parts of coaxial radio components on CNC machines, a study of the features of the production of parts and the standard functionality of CAM systems was carried out. A classification of these parts by the type of equipment, types, serial production, variable parameters within the type, materials, and tools has been developed. The possibilities of the extensibility of the functions of CAM systems, the existing methods of creating and verifying control programs are considered. An example of a successful expansion of the functionality of a standard CAM system in the radio-electronic industry is given - a module for increasing machining accuracy with a constant cutting mode by optimizing the mutual positioning of the tool and the workpiece. Requirements have been developed for the creation of a specialized combined method for verification of control programs using all existing verification capabilities and minimal use of debugging and verification directly on the machine with the maintenance of reference books of worked processing modes in which the number and size of burrs are minimal, as well as a library of control programs equipped with a search system for the parameters of the difference in the execution of parts.
Studying the dynamics of contact interactions during machining based on a system of nonlinear piecewise linear differential equations
Authors: Vasilkov D V , Alexandrov A S , Golikova V V , Kochina T B
Published: February 2021

When manufacturing parts for thermal control systems for operation in especially difficult conditions of the North and in spacecraft, titanium and complex alloyed alloys are used. They are subject to increased quality requirements. They are achieved through simulation modeling. The solution is based on a dynamic model in which the contact interaction between the tool flank and the workpiece is differentiated. The process of contact interaction is considered as two-phase in the form of a sequence of states of adhesion and sliding. In the space of state variables, a system of nonlinear differential equations of piecewise linear type is constructed based on a set of rheological models. Based on this model, simulation modeling was carried out in the form of a computational experiment. A periodic solution is obtained which is formed as a result of switching the sliding and adhesion phases. In the graphs presented in the paper, the transition from the adhesion phase to the sliding phase is accompanied by a surge in displacement. In this case, in the phase portrait, the phase trajectory reaches the limit cycle with a limited amplitude. At the moment of transition from the adhesion phase to the sliding phase, a characteristic deviation of the phase trajectory from the limit cycle with an increased amplitude is observed, followed by a return to the limit cycle. With a wide variation in cutting speed, the conditions for technical stability are determined. During the simulation, a dynamic manifestation of the formation of chip elements was found, which did not have a serious impact on the nature of dynamic processes. The results obtained make it possible to study the dynamics of contact interactions during cutting in the framework of nonlinear dynamic models. This makes it possible to assess the level of vibration amplitudes and determine the regulated parameters of processing accuracy and surface roughness of manufactured products.
Identification of problem parts made by longitudinal stretching when compensating for springing
Authors: Mironenko V V , Govorkov A S
Published: February 2021

The paper considers problem related to the compensation of springing of parts produced by longitudinal stretching. It proposes the method of eliminating this effect by replacing the shaping method with transverse stretching. A finite element simulation of transverse stretching for the selected element produced by longitudinal stretching was carried out. The analysis of results revealed elimination of negative phenomenon of springing. After changing the scheme, the nature of the workpiece movement during springing became classic. The paper describes the procedure for the geometry of the element to determine problems in the compensation of fitting related to springing. The method takes into account the geometric parameters of the curvature radii of the element in different directions and the relations between them. The criteria for identifying problem parts are presented.
Assessment of strength of elements produced using 3D printing technology
Authors: Perelygina A Yu , Raspopina V B , Rudykh A V , Grigorov P A
Published: February 2021

In some cases, 3D-printed products must be able to resist the stresses caused by their functionality. The design of bionic artificial hand is considered as a construction made using 3D printing technology, the strength of which must be assessed. The artificial limb is made using extrusion plastic printing. In order to assess the strength of the artificial limb, the experimental study of the samples made using 3D printing technology was carried out. The influence of three parameters on the strength characteristics of the samples was studied: the percentage of filling, the filling pattern and the direction of the material layering in the sample.
Appropriate use of dissolved gas energy in fields at the final stage of development
Authors: Yusupova L F , Almukhametova E M , Nosirov D S , Safiullina A R
Published: February 2021

In order to improve the development of fields at a later stage, this article considered the use of water-gas repression together with the dissolved gas energy. The theoretical basis of the study is based on the application of the method of physical modeling of oil displacement by water. As a result, it was found that waterflooding would be more effective when such an activity is carried out in the early stages of development. Waterflooding can also be effective in old, depleted fields with shallow depths of oil-bearing horizons. The article states that in flooded deposits, where the reservoir pressure did not drop below the bubble point pressure, it is advisable to reduce the reservoir pressure to the bubble point pressure (to carry out forced withdrawal). After that, water injection should be resumed with 30-50% compensation. It has been established that in order to increase the efficiency of the development of fields developed in the dissolved gas mode, waterflooding must be started at a reservoir pressure that is 30–70% less than the bubble point pressure. The best option for the development of such deposits is the presence of active edge waters. If they are absent, it is advisable to end water in the aquifer with compensation of withdrawals from 20 to 40% after the start of gas extraction from oil.
Micro-electrode channel guide (µECG) technology: an online method for continuous electrical recording in a human beating heart-on-chip
Authors: Visone Roberta , Ugolini Giovanni S , Cruz-Moreira Daniela , Marzorati Simona , Piazza Stefano , Pesenti Enrico , Redaelli Alberto , Moretti Matteo , Occhetta Paola , Rasponi Marco
Published: February 2021

Cardiac toxicity still represents a common adverse outcome causing drug attrition and post-marketing withdrawal. The development of relevant in vitro models resembling the human heart recently opened the path towards a more accurate detection of drug-induced human cardiac toxicity early in the drug development process. Organs-on-chip have been proposed as promising tools to recapitulate in vitro the key aspects of the in vivo cardiac physiology and to provide a means to directly analyze functional readouts. In this scenario, a new device capable of continuous monitoring of electrophysiological signals from functional in vitro human hearts-on-chip is here presented. The development of cardiac microtissues was achieved through a recently published method to control the mechanical environment, while the introduction of a technology consisting in micro-electrode coaxial guides allowed to conduct direct and non-destructive electrophysiology studies. The generated human cardiac microtissues exhibited synchronous spontaneous beating, as demonstrated by multi-point and continuous acquisition of cardiac field potential, and expression of relevant genes encoding for cardiac ion-channels. A proof-of-concept pharmacological validation on three drugs proved the proposed model to potentially be a powerful tool to evaluate functional cardiac toxicity.
Neural ordinary differential equation and holographic quantum chromodynamics
Authors: Hashimoto Koji , Hu Hong-Ye , You Yi-Zhuang
Published: February 2021

The neural ordinary differential equation (neural ODE) is a novel machine learning architecture whose weights are smooth functions of the continuous depth. We apply the neural ODE to holographic QCD by regarding the weight functions as a bulk metric, and train the machine with lattice QCD data of chiral condensate at finite temperature. The machine finds consistent bulk geometry at various values of temperature and discovers the emergent black hole horizon in the holographic bulk automatically. The holographic Wilson loops calculated with the emergent machine-learned bulk spacetime have consistent temperature dependence of confinement and Debye-screening behavior. In machine learning models with physically interpretable weights, the neural ODE frees us from discretization artifact leading to difficult ingenuity of hyperparameters, and improves numerical accuracy to make the model more trustworthy.
A reinforcement learning application of a guided Monte Carlo Tree Search algorithm for beam orientation selection in radiation therapy
Authors: Sadeghnejad-Barkousaraie Azar , Bohara Gyanendra , Jiang Steve , Nguyen Dan
Published: February 2021

Current beam orientation optimization algorithms for radiotherapy, such as column generation (CG), are typically heuristic or greedy in nature because of the size of the combinatorial problem, which leads to suboptimal solutions. We propose a reinforcement learning strategy using a Monte Carlo Tree Search (MCTS) that can find a better beam orientation set in less time than CG. We utilize a reinforcement learning structure involving a supervised learning network to guide the MCTS and to explore the decision space of beam orientation selection problems. We previously trained a deep neural network (DNN) that takes in the patient anatomy, organ weights, and current beams, then approximates beam fitness values to indicate the next best beam to add. Here, we use this DNN to probabilistically guide the traversal of the branches of the Monte Carlo decision tree to add a new beam to the plan. To assess the feasibility of the algorithm, we used a test set of 13 prostate cancer patients, distinct from the 57 patients originally used to train and validate the DNN, to solve five-beam plans. To show the strength of the guided MCTS (GTS) compared to other search methods, we also provided the performances of Guided Search, Uniform Tree Search and Random Search algorithms. On average, GTS outperformed all the other methods. It found a better solution than CG in 237 s on average, compared to 360 s for CG, and outperformed all other methods in finding a solution with a lower objective function value in less than 1000 s. Using our GTS method, we could maintain planning target volume (PTV) coverage within 1% error similar to CG, while reducing the organ-at-risk mean dose for body, rectum, left and right femoral heads; the mean dose to bladder was 1% higher with GTS than with CG.
ALK1 regulates the internalization of endoglin and the type III TGF-β receptor
Authors: Tazat Keren , Pomeraniec-Abudy Leslie , Hector-Greene Melissa , Szilágyi Szabina Szófia , Sharma Swati , Cai Elise M. , Corona Armando L. , Ehrlich Marcelo , Blobe Gerard C. , Henis Yoav I.
Published: February 2021

The relation between complex formation among TGF-β receptors and their endocytosis remained unclear. We show that the complexes formed regulate their endocytosis and signaling, with a major effect by ALK1. Our results link TGF-β receptor oligomerization and endocytosis based on which endocytosis signals are functional in specific receptor complexes.
Associations of Lifestyle and Anthropometric Factors With the Risk of Herpes Zoster: A Nationwide Population-Based Cohort Study
Authors: Schmidt Sigrun A J , Sørensen Henrik Toft , Langan Sinéad M , Vestergaard Mogens
Published: February 2021

The role of lifestyle in development of herpes zoster remains unclear. We examined whether smoking status, alcohol consumption, body mass index, or physical activity were associated with zoster risk. We followed a population-based cohort of 101,894 respondents to the 2010 Danish National Health Survey (baseline, May 1, 2010) until zoster diagnosis, death, emigration, or July 1, 2014, whichever occurred first. We computed hazard ratios for zoster associated with each exposure, using Cox regression with age as the time scale and adjusting for potential confounders. Compared with never smokers, hazards for zoster were increased in former smokers (1.17, 95% confidence interval (CI): 1.06, 1.30), but not in current smokers (1.00, 95% CI: 0.89, 1.13). Compared with low-risk alcohol consumption, neither intermediate-risk (0.95, 95% CI: 0.84, 1.07) nor high-risk alcohol consumption (0.99, 95% CI: 0.85, 1.15) was associated with zoster. We also found no increased hazard associated with weekly binge drinking versus not (0.93, 95% CI: 0.77, 1.11). Risk of zoster varied little by body mass index (referent = normal weight) and physical activity levels (referent = light level), with hazard ratios between 0.96 and 1.08. We observed no dose-response association between the exposures and zoster. The examined lifestyle and anthropometric factors thus were not risk factors for zoster.
A General Propensity Score for Signal Identification Using Tree-Based Scan Statistics
Authors: Wang Shirley V , Maro Judith C , Gagne Joshua J , Patorno Elisabetta , Kattinakere Sushama , Stojanovic Danijela , Eworuke Efe , Baro Elande , Ouellet-Hellstrom Rita , Nguyen Michael , Ma Yong , Dashevsky Inna , Cole David , DeLuccia Sandra , Hansbury Aaron , Pestine Ella , Kulldorff Martin
Published: February 2021

The tree-based scan statistic (TreeScan; Martin Kulldorff, Harvard Medical School, Boston, Massachusetts) is a data-mining method that adjusts for multiple testing of correlated hypotheses when screening thousands of potential adverse events for signal identification. Simulation has demonstrated the promise of TreeScan with a propensity score (PS)-matched cohort design. However, it is unclear which variables to include in a PS for applied signal identification studies to simultaneously adjust for confounding across potential outcomes. We selected 4 pairs of medications with well-understood safety profiles. For each pair, we evaluated 5 candidate PSs with different combinations of 1) predefined general covariates (comorbidity, frailty, utilization), 2) empirically selected (data-driven) covariates, and 3) covariates tailored to the drug pair. For each pair, statistical alerting patterns were similar with alternative PSs (≤11 alerts in 7,996 outcomes scanned). Inclusion of covariates tailored to exposure did not appreciably affect screening results. Inclusion of empirically selected covariates can provide better proxy coverage for confounders but can also decrease statistical power. Unlike tailored covariates, empirical and predefined general covariates can be applied “out of the box” for signal identification. The choice of PS depends on the level of concern about residual confounding versus loss of power. Potential signals should be followed by pharmacoepidemiologic assessment where confounding control is tailored to the specific outcome(s) under investigation.
Age and Body Mass Index Affect Patient Satisfaction Following Reduction Mammoplasty: A Multicenter Study Using BREAST-Q
Authors: Jørgensen Mads Gustaf , Albertsdottir Elin , Dalaei Farima , Hesselfeldt-Nielsen Jørgen , Schmidt Volker-Jürgen , Sørensen Jens Ahm , Toyserkani Navid Mohamadpour
Published: February 2021

Background

Reduction mammoplasty effectively improves quality of life for women with macromastia. However, little is known whether surgical- or patient-related factors affect satisfaction.

Objective

The authors sought to investigate factors associated with altered patient satisfaction following reduction mammoplasty.

Methods

A cross-section study was performed by sending the BREAST-Q Reduction module to all patients who had undergone reduction mammoplasty between January 2009 and December 2018 at 2 tertiary Danish hospitals. Demographics and pre-, peri-, and postoperative details were gathered from electronic medical records.

Results

A total of 393 patients returned the questionnaire and were eligible for the study. Increasing age at the time of surgery was associated with higher satisfaction with breasts nipples, headache, psychosocial well-being, and outcome. Increased body mass index at the time of surgery negatively affected satisfaction with breasts and psychosocial well-being. Increase in body mass index after surgery was further associated with lower satisfaction with breasts, nipples, sexual well-being, and more pain in the breast area. Postoperative scar revision and wound infection was more common following inferior pedicle technique than superomedial technique and negatively affected satisfaction with outcome and pain in the breast area.

Conclusions

Patients should be motivated to optimize their weight prior to reduction mammoplasty to achieve optimal satisfaction. Age was associated with improved patient satisfaction, which should considered when operating on younger patients. Postoperative complications affect patient satisfaction, and the superomedial technique seems to be a better choice than the inferior pedicle technique in medium-large breasts.

Level of Evidence: 4
Asian Upper Blepharoplasty in Women: A Comprehensive Approach for a Natural and Aesthetically Pleasing Outcome
Authors: Wang Chunmei , Mei Xiaoxia , Pu Lee L Q
Published: February 2021

Background

Asian upper blepharoplasty is the most popular cosmetic procedure for Asian women. However, there is no standardized approach to this procedure and suboptimal results are still common.

Objectives

The aim of this article was to describe a comprehensive approach to Asian upper blepharoplasty in women and report the clinical outcomes obtained with this approach.

Methods

The comprehensive approach described here for Asian upper blepharoplasty in women includes: (1) determining the height and length of the upper eyelid skin crease; (2) creating a more optimal anatomy of the upper eyelid by removing excess eyelid skin, a portion of the orbicularis oculi muscle, and septal fat; (3) reconstructing the desired anatomic structures of the upper eyelid skin crease through plication of the levator aponeurosis, if necessary, and closure of the upper eyelid skin incision through the septum and the mobile portion of the levator aponeurosis; (4) adding a medial epicanthoplasty if needed to enhance final cosmetic results.

Results

Over a 5-year period, 332 Asian women underwent upper blepharoplasty for creation of double eyelids, or conversion from less visible to more ideal double eyelids, with the above comprehensive approach. There were no surgical complications postoperatively and 326 patients (98.2%) rated their outcome satisfactory over a 5-year follow-up. Only 6 patients (1.8%) required surgical revision for asymmetry or suboptimal shape of the upper eyelid.

Conclusions

The comprehensive approach to Asian upper blepharoplasty described here can be used for Asian women and produces a natural and aesthetically pleasing outcome and low revision rates.

Level of Evidence: 4
Folded Cymba Concha: Is It Large and Stable Enough for Caudal Septal Extension Graft in Asian Rhinoplasty?
Authors: Namgoong Sik , Kim Soobyn , Kim Hyung-Rok , Jeong Seong-Ho , Han Seung-Kyu , Dhong Eun-Sang
Published: February 2021

Background

Septal extension grafting (SEG) is used for nasal tip projection and positioning. Often, insufficient quadrangular cartilage is available for grafting in Asians, and in most secondary cases the septum is already harvested. We utilized the folded cymba concha as an alternative for caudal SEG (CSEG) by modifying a tongue-in-groove technique.

Objectives

The aim of this study was to evaluate the physical suitability of the cymba concha for CSEG and compare its outcomes with those of septal quadrangular cartilage.

Methods

The mean length and width of 311 harvested consecutive folded cymba conchae were measured from intraoperative photographs. Data from 220 patients with >12 months of follow-up were retrospectively reviewed for clinical outcomes. Clinical demography was determined based on the need for additional spreader grafts. For clinical reliability, anthropometric photographs of patients in whom folded cymba conchae were used were compared with those in whom quadrangular cartilage was used.

Results

Mean [standard deviation] lengths and widths of the folded cymba conchae in men and women were 24.2 [3.9] and 22.4 [3.7] mm, and 7.8 [1.9] and 7.2 [1.9] mm, respectively. Use of the folded cymba concha graft significantly increased nasal tip projection by 28.9% and columellar-labial angle by 9.7%, improving both aspects postoperatively. Anthropometric comparison revealed no significant differences between folded cymba conchae and septal cartilage in terms of nasal tip projection (P = 0.264) and postoperative columellar-labial angle (P = 0.182).

Conclusions

Folded cymba conchal cartilage can be a primary option for CSEG in Asian septorhinoplasty cases or for individuals with insufficient septal cartilage remnants.
NetQuilt: deep multispecies network-based protein function prediction using homology-informed network similarity
Authors: Barot Meet , Gligorijević Vladimir , Cho Kyunghyun , Bonneau Richard
Published: February 2021

Motivation

Transferring knowledge between species is challenging: different species contain distinct proteomes and cellular architectures, which cause their proteins to carry out different functions via different interaction networks. Many approaches to protein functional annotation use sequence similarity to transfer knowledge between species. These approaches cannot produce accurate predictions for proteins without homologues of known function, as many functions require cellular context for meaningful prediction. To supply this context, network-based methods use protein-protein interaction (PPI) networks as a source of information for inferring protein function and have demonstrated promising results in function prediction. However, most of these methods are tied to a network for a single species, and many species lack biological networks.

Results

In this work, we integrate sequence and network information across multiple species by computing IsoRank similarity scores to create a meta-network profile of the proteins of multiple species. We use this integrated multispecies meta-network as input to train a maxout neural network with Gene Ontology terms as target labels. Our multispecies approach takes advantage of more training examples, and consequently leads to significant improvements in function prediction performance compared to two network-based methods, a deep learning sequence-based method and the BLAST annotation method used in the Critial Assessment of Functional Annotation. We are able to demonstrate that our approach performs well even in cases where a species has no network information available: when an organism’s PPI network is left out we can use our multi-species method to make predictions for the left-out organism with good performance.

Availability and implementation

The code is freely available at https://github.com/nowittynamesleft/NetQuilt. The data, including sequences, PPI networks and GO annotations are available at https://string-db.org/.

Supplementary information

Supplementary data are available at Bioinformatics online.
Inference of gene regulatory networks using pseudo-time series data
Authors: Zhang Yuelei , Chang Xiao , Liu Xiaoping
Published: February 2021

Motivation

Inferring gene regulatory networks (GRNs) from high-throughput data is an important and challenging problem in systems biology. Although numerous GRN methods have been developed, most have focused on the verification of the specific dataset. However, it is difficult to establish directed topological networks that are both suitable for time-series and non-time-series datasets due to the complexity and diversity of biological networks.

Results

Here, we proposed a novel method, GNIPLR (Gene networks inference based on projection and lagged regression) to infer GRNs from time-series or non-time-series gene expression data. GNIPLR projected gene data twice using the LASSO projection (LSP) algorithm and the linear projection (LP) approximation to produce a linear and monotonous pseudo-time series, and then determined the direction of regulation in combination with lagged regression analyses. The proposed algorithm was validated using simulated and real biological data. Moreover, we also applied the GNIPLR algorithm to the liver hepatocellular carcinoma (LIHC) and bladder urothelial carcinoma (BLCA) cancer expression datasets. These analyses revealed significantly higher accuracy and AUC values than other popular methods.

Availabilityand implementation

The GNIPLR tool is freely available at https://github.com/zyllluck/GNIPLR.

Supplementary information

Supplementary data are available at Bioinformatics online.
Ex vivo normothermic perfusion of isolated segmental porcine bowel: a novel functional model of the small intestine
Authors: Hamed M O , Barlow A D , Dolezalova N , Khosla S , Sagar A , Gribble F M , Davies S , Murphy M P , Hosgood S A , Nicholson M L , Saeb-Parsy K
Published: February 2021

Background

There is an unmet need for suitable ex vivo large animal models in experimental gastroenterology and intestinal transplantation. This study details a reliable and effective technique for ex vivo normothermic perfusion (EVNP) of segmental porcine small intestine.

Methods

Segments of small intestine, 1.5–3.0 m in length, were retrieved from terminally anaesthetized pigs. After a period of cold ischaemia, EVNP was performed for 2 h at 37°C with a mean pressure of 80 mmHg using oxygenated autologous blood diluted with Ringer’s solution. The duration of EVNP was extended to 4 h for a second set of experiments in which two segments of proximal to mid-ileum (1.5–3.0 m) were retrieved from each animal and reperfused with whole blood (control) or leucocyte-depleted blood to examine the impact of leucocyte depletion on reperfusion injury.

Results

After a mean cold ischaemia time of 5 h and 20 min, EVNP was performed in an initial group of four pigs. In the second set of experiments, five pigs were used in each group. In all experiments bowel segments were well perfused and exhibited peristalsis during EVNP. Venous glucose levels significantly increased following luminal glucose stimulation (mean(s.e.m.) basal level 1.8(0.6) mmol/l versus peak 15.5(5.8) mmol/l; P < 0.001) and glucagon-like peptide 1 (GLP-1) levels increased in all experiments, demonstrating intact absorptive and secretory intestinal functions. There were no significant differences between control and leucocyte-depleted animals regarding blood flow, venous glucose, GLP-1 levels or histopathology at the end of 4 h of EVNP.

Conclusions

This novel model is suitable for the investigation of gastrointestinal physiology, pathology and ischaemia reperfusion injury, along with evaluation of potential therapeutic interventions.
Annexin A1 restores cerebrovascular integrity concomitant with reduced amyloid-β and tau pathology
Authors: Ries Miriam , Watts Helena , Mota Bibiana C , Lopez Maria Yanez , Donat Cornelius K , Baxan Nicoleta , Pickering James A , Chau Tsz Wing , Semmler Annika , Gurung Brinda , Aleksynas Robertas , Abelleira-Hervas Laura , Iqbal Soha Jamshed , Romero-Molina Carmen , Hernandez-Mir Gerard , d’Amati Antonio , Reutelingsperger Chris , Goldfinger Marc H , Gentleman Steve M , Van Leuven Fred , Solito Egle , Sastre Magdalena
Published: February 2021

Alzheimer’s disease, characterized by brain deposits of amyloid-β plaques and neurofibrillary tangles, is also linked to neurovascular dysfunction and blood–brain barrier breakdown, affecting the passage of substances into and out of the brain. We hypothesized that treatment of neurovascular alterations could be beneficial in Alzheimer’s disease. Annexin A1 (ANXA1) is a mediator of glucocorticoid anti-inflammatory action that can suppress microglial activation and reduce blood–brain barrier leakage. We have reported recently that treatment with recombinant human ANXA1 (hrANXA1) reduced amyloid-β levels by increased degradation in neuroblastoma cells and phagocytosis by microglia. Here, we show the beneficial effects of hrANXA1 in vivo by restoring efficient blood–brain barrier function and decreasing amyloid-β and tau pathology in 5xFAD mice and Tau-P301L mice. We demonstrate that young 5xFAD mice already suffer cerebrovascular damage, while acute pre-administration of hrANXA1 rescued the vascular defects. Interestingly, the ameliorated blood–brain barrier permeability in young 5xFAD mice by hrANXA1 correlated with reduced brain amyloid-β load, due to increased clearance and degradation of amyloid-β by insulin degrading enzyme (IDE). The systemic anti-inflammatory properties of hrANXA1 were also observed in 5xFAD mice, increasing IL-10 and reducing TNF-α expression. Additionally, the prolonged treatment with hrANXA1 reduced the memory deficits and increased synaptic density in young 5xFAD mice. Similarly, in Tau-P301L mice, acute hrANXA1 administration restored vascular architecture integrity, affecting the distribution of tight junctions, and reduced tau phosphorylation. The combined data support the hypothesis that blood–brain barrier breakdown early in Alzheimer’s disease can be restored by hrANXA1 as a potential therapeutic approach.
Preparation of Monolithic Silica and Polymer Capillary Columns with Ultrahigh Column Efficiencies and Comparisons between van Deemter Plots of Alkylbenzenes on These Two Kinds of Columns
Authors: Ping Guichen , Hou Weiping , Shi Quanquan , Ding Hongjing , Gong Xia , Li Jinmei , Xu Hui
Published: February 2021

Monolithic silica and polymer capillary columns with ultrahigh column efficiencies were prepared. Permeability and electrochromatography performances of these two kinds of columns were compared. Monolithic silica columns bear higher permeability than polymer counterparts by two orders of magnitude. Furthermore, the van Deemter plots of alkylbenzenes on these two kinds of columns demonstrate that monolithic silica columns produce much lower plate heights of alkylbenzes than polymer columns do. Within the range of electroosmotic flow (EOF) velocity investigated, no uptrend of plate height with the increase of EOF was observed suggesting the great capacity of fast separation and high efficiency. The plate height of thiourea on monolithic silica columns is as low as 2.67 μm, representing its corresponding column efficiency is over 430,000 plates/m. As far as we know, it is the highest ever column efficiency reported in the literature. Moreover, the separation of butylbenzene isomers was obtained on the monolithic silica column.
Deficiency of inactive rhomboid protein 2 (iRhom2) attenuates diet-induced hyperlipidaemia and early atherogenesis
Authors: Hannemann Carmen , Schecker Johannes H , Brettschneider Alica , Grune Jana , Rösener Nicole , Weller Andrea , Stangl Verena , Fisher Edward A , Stangl Karl , Ludwig Antje , Hewing Bernd
Published: February 2021

Aims

Atherosclerosis is a chronic inflammatory disease of the arterial vessel wall and anti-inflammatory treatment strategies are currently pursued to lower cardiovascular disease burden. Modulation of recently discovered inactive rhomboid protein 2 (iRhom2) attenuates shedding of tumour necrosis factor-alpha (TNF-α) selectively from immune cells. The present study aims at investigating the impact of iRhom2 deficiency on the development of atherosclerosis.

Methods and results

Low-density lipoprotein receptor (LDLR)-deficient mice with additional deficiency of iRhom2 (LDLR−/−iRhom2−/−) and control (LDLR−/−) mice were fed a Western-type diet (WD) for 8 or 20 weeks to induce early or advanced atherosclerosis. Deficiency of iRhom2 resulted in a significant decrease in the size of early atherosclerotic plaques as determined in aortic root cross-sections. LDLR−/−iRhom2−/− mice exhibited significantly lower serum levels of TNF-α and lower circulating and hepatic levels of cholesterol and triglycerides compared to LDLR−/− mice at 8 weeks of WD. Analyses of hepatic bile acid concentration and gene expression at 8 weeks of WD revealed that iRhom2 deficiency prevented WD-induced repression of hepatic bile acid synthesis in LDLR−/− mice. In contrast, at 20 weeks of WD, plaque size, plaque composition, and serum levels of TNF-α or cholesterol were not different between genotypes.

Conclusion

Modulation of inflammation by iRhom2 deficiency attenuated diet-induced hyperlipidaemia and early atherogenesis in LDLR−/− mice. iRhom2 deficiency did not affect diet-induced plaque burden and composition in advanced atherosclerosis in LDLR−/− mice.