bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on dynamic characteristics of gun turret under launching load
Authors: Li Y , Yang G W , Meng Q Z , Wang K Z
Published: June 2023

The purpose of this study is to further study the dynamic characteristics of gun turret under firing load. Firstly, the relative motion between inner ring and outer ring was decomposed into axial translational motion, radial translational motion and rotational freedom in two orthogonal radial planes in order to solve the problem of large number of ball bearings and complex contact calculation in the actual structure of turret ring. Then, the equivalent dynamic mathematical model of turret ring was established. Based on the finite element method, the turret ring is equivalent to Bushing with body-body connection type, Multi-point constraints algorithm and Deformable Behavior attribute. The equivalent stiffness of the turret ring is set as linear stiffness, and the turret dynamic model is established. The dynamic response simulation of the turret under the action of firing load was carried out. The acceleration sensor was arranged at the left trunnion position of the turret, and the acceleration generated by the transient force during firing was measured at the left trunnion position. The results showed that the test value of the acceleration at the left trunnion position was 1304.38m /s2,the simulation value of the turret dynamic model is 1425 m/s2, and the error is 8.46%, which verifies the accuracy of the turret dynamic model and indicates that the turret dynamic model can reflect the dynamic characteristics of the turret well.
Study of seat dynamics under transient strong impact load
Authors: Li Y , Tian N , Wang H J , Dou X
Published: June 2023

The turret seat ring assumes an important load transfer role in the gun firing process, and its stiffness has a great influence on the muzzle vibration response. Based on the basic theory of nonlinear finite element method, this paper establishes a high-precision refined finite element analysis model of the seat ring based on the contact and collision between the ring and the steel ball, the steel ball and the fixed ring, and the fitting gap between the steel ball and the ring and the fixed ring, and characterizes the equivalent stiffness of the seat ring by its axial equivalent stiffness, radial equivalent stiffness and overturning equivalent stiffness. The dynamic response is obtained by simulation. The results show that the axial equivalent stiffness, radial equivalent stiffness and overturning equivalent stiffness of the seat ring are non-linear in a certain load range, and the equivalent stiffness changes linearly and steadily with the increase of load, and fluctuates in a small range.
Design of initiating explosives for semiconductor bridge Primer for rapid-fire projectiles
Authors: Ren Wei , Li Hui , Yingke Chang , Chu En-yi , Chen Jian-hua , Li Jiao
Published: June 2023

Based on SCB (semiconductor bridge) chip technology, this paper designs a semiconductor bridge ignition component in the standard primer shell, and designs a primer prototype for the high instantaneous, high safety, and high consistency ignition requirements of the current rapid-fire projectiles for the primer of pyrotechnics. First of all, the design and study of a high instantaneous, insensitive SCB chip can meet the safety of 1A1W5min without fire, while reducing the fire time and fire energy; secondly, the research on the packaging technology of SCB chips is carried out. Combined with PCB or ceramic parts, a flat package structure is designed and matched with the standard primer structure. At the same time, the design and performance test of the semiconductor bridge primer for rapid-fire projectiles has been completed. The results show that the action time of the prototype the integrated primer is ≯200µs, and the dispersion is ≯30µs; compared with the current electric primer product, its safety, instantaneousness, and action time are more consistent, and the overall performance is better.
A magnetic field constrained type of multi-barrel common-rail railgun
Authors: Guo Wei , Zhang Tao , Mu Zeyuan , Zhu Wenfang , Li Mingtao
Published: June 2023

Adopting the simultaneous launch mode of small and medium caliber railgun is an important means to increase the firepower density, improve the hit probability and strike efficiency. Based on this requirement, this paper creatively proposed a new multi-barrel simultaneous launch EM railgun, named magnetic field constrained type of multi-barrel common-rail railgun. The basic idea is to integrate multiple single-turn rail launchers with a specific structure into one launcher, and “merge” one rail of each single-turn rail launcher with a tight structure combination and arrange it in the center to form the “common rail” of multi-barrel launcher. The other rail of each rail launcher is evenly distributed around the “common rail” in the form of petals, forming the “outer rail” of each rail launcher. “Common rail” and all “outer rails” together form a multi-barrel rail launcher. With the increase of the number of barrels, the current of each barrel is superimposed many times in the common-rail, which greatly improves the magnetic induction intensity of the inner bore, thus improving the launching efficiency of the system. In order to overcome the problem of high magnetic induction intensity near the common-rail and low magnetic induction intensity near the external rail caused, a magnetic field constrained structure is added to the external rail to form a magnetic field constrained type of multi-barrel common-rail railgun. The basic structure of electromagnetic railgun with different number of barrels is simulated, and the spatial distribution characteristics of magnetic field are analyzed. Based on the magnetic field analysis, the interior ballistic simulation of the multi-barrel common-rail railgun is carried out, and the interior ballistic characteristics and launching efficiency of various numbers of barrels are analyzed. The simulation results show that the magnetic field constrained type of multi-barrel common-rail railgun can effectively improve the magnetic induction intensity near the external rail, improve the uniformity of the magnetic induction intensity distribution in the inner bore, and improve the inductance gradient, thus increasing the system efficiency. The structure of the multi-barrel common-rail railgun provides a new idea for the engineering application of the multi-barrel simultaneous launch mode.
Research on Error Transfer Model and Simulation of Aircraft Gun Structure
Authors: Liu B , Liu J , Yan S B , Wang K
Published: June 2023

In order to study the influence of structural motion and geometric error on the firing density during the firing of the aircraft gun, based on the multi-body dynamics theory, the structural topology of the aircraft gun was established, and the motion error coordinate relationship was constructed by the firing chain and the support chain of the aircraft gun. Establish motion transformation matrix and error transformation matrix between adjacent volumes. Further, the error transfer model of the aircraft gun firing process is constructed. The transmission law of the muzzle offset error caused during the firing of the aircraft gun is revealed. Then the model is simulated and analyzed, and the parameters such as test position error, motion error and muzzle vibration displacement under different firing rates are identified. Finally, the simulation results are compared with the experimental test results. The results show that the average error rate in the azimuth direction is 3.94%, and the average error rate in the pitch direction is 6.86%. The error rate in the pitch direction is significantly higher than that in the azimuth direction, and the measured offset values are higher than the simulated values, which verifies the validity and correctness of the model. It can meet the engineering design requirements and provide the basis for the structural design and optimization of the aircraft gun.
Titanium Alloy Artillery Barrel and Radial Precision Forging Technology Discussion
Authors: Jiayong Zhou , Fanzhe Meng , Xiaopu Wu
Published: June 2023

The application of titanium alloy barrel in artillery weapon system can effectively reduce the weight of artillery, which is significant to enhance its mobility, precision strike capability and battlefield survivability. Based on the review of relevant literature, the development and application of titanium alloy and titanium alloy barrel and barrel forging process are summarized, which lays the technical foundation for the research of titanium alloy barrel radial precision forging technology. At the same time, the current problems of titanium alloy artillery barrel radial precision forging are proposed, and the corresponding pre-solution is given, which has important research value and practical significance to effectively improve the comprehensive performance of titanium alloy barrel. It has an important research value and practical significance to effectively improve the comprehensive performance of titanium alloy barrel.
Application of Modular Expression of Bond Space in Muzzle Disturbance Analysis
Authors: He F , Wang M S , Liu Z L
Published: June 2023

In order to simulate the complex dynamic behavior of automata system and analyze muzzle disturbance, a modular dynamic model of automata was established based on bond space theory. The bond space modules of the cradle, gun box, barrel and projectile were defined, and the state equations of each module of the automata were deduced in terms of momentum space vector and position change space vector and their first derivative. The whole model is established by connecting the generalized potential source and generalized flow source of each module. On this basis, the muzzle disturbance analysis is carried out by solving the model, and the simulation results are consistent with the test results of the continuous firing test. It shows that the muzzle disturbance analysis model based on the modular representation of bond space is correct, and provides a new method for the dynamic analysis of the projectile and gun coupling launching system.
Research on variable stiffness characteristics of turntable bearing under heavy load condition based on FEM
Authors: Kong Fan-kai , Zhao Jia-wei , Nie Chong-yang , Chen Fei , Zhang Nan
Published: June 2023

Based on ANSYS finite element analysis software, a method of extracting stiffness matrix of four-point contact ball bearing was proposed. The finite element model of four-point contact ball bearing was established, the stress and strain of the bearing under different loads were calculated, and the relationship between load and stress and strain was analyzed, The global stiffness matrices of turntable bearing with steel and aluminum as inner ring materials are extracted and compared, and the causes of large changes in the matrix are analyzed.
Dynamic Analysis and Optimization of a CTA Gun With the Soft Recoil Technology Based on Adams
Authors: Han RuFeng , Zhang Long , Niu TianHong , Ke Biao , Li Rui
Published: June 2023

Aimed at the object of the recoil minimization of a cased telescoped ammunition (CTA) gun with the soft recoil system, a dynamic model was establishedbased on the characteristics and the assumptions of the fire-out-of-battery(FOOB) principle and dynamic characteristics were obtained by Adams simulation analysis. Based on these results, an optimization model was established to reduce the recoil, and the key parameters of the firing platform were optimized by the optimization algorithm. The simulation results show that the maximum recoil was reduced about 10% without affecting system performance, which effectively improved the firing stability and the overall performance of the weapon system.
Emergent geometry, torsion and anomalies in non-relativistic topological matter
Authors: Nissinen Jaakko
Published: June 2023

I review and discuss aspects of the interplay of emergent geometry and anomalies in topological semimetals and insulators, focusing on effects of torsion. This correspondence identifies torsional topological responses in terms of anomalies and anomaly related hydrodynamic phenomena involving gauge fields and geometry. I discuss how torsional emergent geometry arises from elastic deformations in crystalline materials and how this background couples to thee low-energy continuum models inherited from lattice models, utilizing the semiclassical expansion. Via the coupling of momentum space topology and emergent vielbein geometry, non-relativistic topological matter can realise new geometrical responses of mixed gauge-gravitational character. The topological low-energy torsional responses depend momentum space geometry, lattice momenta and the regularization and UV completion, provided by the non-relativistic physics and symmetries of topological materials.
Trace anomalies for Weyl fermions: too odd to be true?
Authors: Abdallah S , Franchino-Viñas S A , Fröb M B
Published: June 2023

We review recent discussions regarding the parity-odd contribution to the trace anomaly of a chiral fermion. We pay special attention to the perturbative approach in terms of Feynman diagrams, comparing in detail the results obtained using dimensional regularization and the Breitenlohner–Maison prescription with other approaches.
Dynamics of strongly-coupled chiral gauge theories
Authors: Bolognesi Stefano , Konishi Kenichi , Luzio Andrea
Published: June 2023

We study the dynamics of SU(N) chiral gauge theories with massless fermions belonging to various combinations of the symmetric, antisymmetric or fundamental representations. We limit ourselves to the gauge-anomaly-free and asymptotically free systems. These theories have a global symmetry group with the associated ’t Hooft anomaly-matching conditions severely limiting the possible RG flows. Recent developments on the applications of the generalized symmetries and the stronger requirement of the matching of the mixed anomalies also give further indications on the possible IR dynamics. In vectorlike theories such as the quantum chromodynamics (QCD), gauge-invariant “quark-antiquark” condensates form and characterize the IR dynamics, and the anomaly matching involves the Nambu-Goldstone (NG) bosons. In some other special cases, such as the Bars-Yankielowicz (BY) or Georgi-Glashow (GG) models, a hypothetical solution was proposed in the literature, with no global symmetry breaking and with some simple set of composite massless fermions saturating all the anomalies. For the BY and GG systems, actually, a more plausible candidate for their IR physics is the dynamical Higgs phase, with a few simple bi-fermion color-flavor locked condensates, breaking the color and flavor symmetries, partially or totally. Remarkably, the ’t Hooft anomaly-matching (and generalized anomaly-matching) conditions are automatically satisfied in this phase. Another interesting possibility, occurring in some chiral gauge theories, is dynamical Abelianization, familiar from N = 2 supersymmetric gauge theories. We explore here even more general types of possible IR phases than the ones mentioned above, for wider classes of models. With the help of large-N arguments we look for IR free theories, whereas the MAC (maximal attractive channel) criterion might suggest some simple bi-fermion condensates characterizing the IR dynamics of the systems. In many cases the low-energy effective theories are found to be described by quiver-like gauge theories, some of the (nonAbelian) gauge groups are infrared-free while some others might be asymptotically free.
Superradiance and quantum states on black hole space-times
Authors: Balakumar Visakan , Bernar Rafael , Winstanley Elizabeth
Published: June 2023

We consider the definition of the Boulware and Hartle-Hawking states for quantum fields on black hole space-times. The properties of these states on a Schwarzschild black hole have been understood for many years, but neither of these states has a direct analogue on a Kerr black hole. We show how superradiant modes play an important role in the definition of quantum states on Kerr. Superradiance is also present on static black hole space-times, in particular for a charged scalar field on a Reissner-Nordström black hole. We explore whether analogues of the Boulware and Hartle-Hawking states exist in this situation.
Scale-invariant inflation
Authors: Rinaldi M , Cecchini C , Ghoshal A , Mukherjee D
Published: June 2023

We examine a scalar-tensor model of gravity that is globally scale-invariant. When adapted to a spatially flat Robertson-Walker metric, the equations of motion describe a dynamical system that flows from an unstable de Sitter space to a stable one. We show that during this transition inflation can occur. Moreover, at the final fixed point, a mass scale naturally emerges that can be identified with the Planck mass. We compute the inflationary spectral indices and the tensor perturbation and we compare them with observations. We also study the possibility that primordial magnetic fields are generated during inflation.
Mining the quantum vacuum: quantum tunnelling and particle creation
Authors: Moss Ian G. , Stasiak Piotr Z.
Published: June 2023

Particle production from the vacuum is a remarkable aspect of particle physics. Prime examples are the Schwinger process of particle production in strong electric fields and the Hawking process of particle production from black holes. These processes can be viewed as quantum tunnelling of particles from the vacuum. The tunnelling approach, and the closely related instanton or complex path approaches, are reviewed here with emphasis on paths in the complex coordinate plane. The method is applied to particle production from a black hole in a magnetic field, where ultra-high energy charged particles are produced.
Introduction to gravitational redshift of quantum photons propagating in curved spacetime
Authors: Alanís Rodríguez L A , Schell A W , Bruschi D E
Published: June 2023

Gravitational redshift is discussed in the context of quantum photons propagating in curved spacetime. A brief introduction to modelling realistic photons is first presented and the effect of gravity on the spectrum computed for photons largely confined along the direction of propagation. It is then shown that redshift-induced transformations on photon operators with sharp momenta are not unitary, while a unitary transformation can be constructed for realistic photons with finite bandwidth. The unitary transformation obtained is then characterized as a multimode mixing operation, which is a generalized rotation of the Hilbert-space basis. Finally, applications of these results are discussed with focus on performance of quantum communication protocols, exploitation of the effects for quantum metrology and sensing, as well as potential for tests of fundamental science.
Higher derivative Hamiltonians with benign ghosts from affine Toda lattices
Authors: Fring Andreas , Turner Bethan
Published: June 2023

We provide further evidence for Smilga’s conjecture that higher charges of integrable systems are suitable candidates for higher derivative theories that possess benign ghost sectors in their parameter space. As concrete examples we study the properties of the classical phase spaces for a number of affine Toda lattices theories related to different types of Kac–Moody algebras. We identify several types of scenarios for theories with higher charge Hamiltonians: some that possess oscillatory, divergent, benign oscillatory and benign divergent behaviour when ghost sectors are present in the quantum theory. No divergent behaviour was observed for which the trajectories reach a singularity in finite time. For theories based on particular representations for the Lie algebraic roots we found an extreme sensitivity towards the initial conditions governed by the Poisson bracket relations between the centre-of-mass coordinate and the charges.
Contact Lie systems: theory and applications
Authors: de Lucas Javier , Rivas Xavier
Published: June 2023

A Lie system is a time-dependent system of differential equations describing the integral curves of a time-dependent vector field that can be considered as a curve in a finite-dimensional Lie algebra of vector fields V. We call V a Vessiot–Guldberg Lie algebra. We define and analyse contact Lie systems, namely Lie systems admitting a Vessiot–Guldberg Lie algebra of Hamiltonian vector fields relative to a contact manifold. We also study contact Lie systems of Liouville type, which are invariant relative to the flow of a Reeb vector field. Liouville theorems, contact Marsden–Weinstein reductions, and Gromov non-squeezing theorems are developed and applied to contact Lie systems. Contact Lie systems on three-dimensional Lie groups with Vessiot–Guldberg Lie algebras of right-invariant vector fields and associated with left-invariant contact forms are classified. Our results are illustrated with examples having relevant physical and mathematical applications, e.g. Schwarz equations, Brockett systems, quantum mechanical systems, etc. Finally, a Poisson coalgebra method to derive superposition rules for contact Lie systems of Liouville type is developed.
The effect of several postharvest processing on the quality of Robusta Coffee (Coffea canephora)
Authors: Linda Monika , Bastian Februadi , Mahendradatta Meta , Tawali Abu Bakar , Laga Amran
Published: June 2023

Postharvest processing, especially in picking, is an essential factor affecting the quality of Robusta coffee (Coffea canephora). This study was aimed to compare the effect of Postharvest processing on the quality of Robusta coffee. The Postharvest methods used in this research were the farmer’s metods, natural process, semi-wet, and wet methods. The observed parameters in this study were physical quality, caffeine content and chlorogenic acid content. The results showed that the physical quality of the farmer’s process, the dirt content exceeded 0.5%, had black seeds, cracked black, cocoa beans, cracked seeds, and hollow seeds which were higher than SNI (Indonesian National Standard) with quality number four based on the defect value. While the quality of the natural, semi-wet and wet methods was in accordance with SNI with quality number two. The results of further testing for the farmer method obtained caffeine content of 1.80% and chlorogenic acid content of 1.00%, natural method of 1.79 % caffeine and chlorogenic acid of 1.32%, the semi-wet method caffeine of 1.92% and chlorogenic acid of 1.28 %, wet method of the caffeine of 1.83% and chlorogenic acid of 1.25%. This shows that the processing with the lowest quality is shown in the processing method of farmers.
Efficiency analysis of tumbu sugarcane production using DEA (Data Envelopment Analysis) in Dawe District, Kudus Regency
Authors: Khadafi Muammar , Suwarto  , Barokah Umi
Published: June 2023

Tumbu sugar is sugar that is produced using sugar cane as raw material which is packed with woven bamboo. This research aims to evaluate the technical efficiency of using tumbu sugar production inputs in Dawe District, Kudus Regency. This research uses secondary data and primary data from questionnaires, the population in this study as many as 192 tumbu sugar craftsmen then testing the population using the slovin formula and obtained 85 samples of tumbu sugar craftsmen in Dawe District. Data analysis using data envelopment analysis (DEA) with DEAP2.1 software application. The results showed that 46 tumbu sugar craftsmen (54.12%) were currently in an inefficient position. According to the SE value, 39 tumbu sugar producers (45.88%) have reached full efficiency, indicating that the DMU has met both the CRS and VRS assumptions. There are no powdered sugar craftsmen who experience DRS. This means that tumbu sugar craftsman must currently enhance the quantity of existing inputs to attain efficiency.
Water management model of Sei Teras fishpond irrigation area in the Central Kalimantan food estate program
Authors: Hermawanto Hanny Adityanta , Rahardjo Adam Pamudji , Kamulyan Budi
Published: June 2023

This study aims to apply semi-technical irrigation technology as an intermediate plan before an advanced development of the Sei Teras fishpond Irrigation Area can be established. Results of the previous study show that the availability of saline and freshwater sources enables the Sei Teras fishpond irrigation area to be developed into a semi-intensive advanced cultivation level. This study evaluates an alternative scheme of fresh and saline water management, which enlarges channel capacity and introduces gates. The evaluation compares the alternative schemes of hydraulic and water quality performance against the existing conditions using the HEC-RAS. The boundary conditions for modelling are obtained from measurement and Secondary data of the previous studies. The measured data are salinity, tides, and channel flow velocity. The parameters being compared are the discharge capacity, tidal water level, and salinity. The evaluation points are located at the Primary and Secondary channels. The simulation results show that enlargement of the channel capacity can increase the discharge to 129,22% at the evaluation point, but no significant water level change. Furthermore, the salinity level can maintain the aquaculture requirement by assigning the gates. Therefore, the alternative development scheme of the pond irrigation system is feasible and supports shrimp cultivation.
Characteristics of dried noodle analogue made from sorghum flour and rice flour added with konjac glucomannan
Authors: Halim Yuniwaty , Angelina Brigitta , Hardoko Hardoko , Handayani Ratna
Published: June 2023

The high popularity of wheat-based food such as noodles in Indonesia has caused a large increase in wheat imports. Sorghum and rice are two local ingredients found in Indonesia; however, sorghum is not largely used as the main grain source, especially in noodle making. This research aimed to determine the effect of the ratio between sorghum flour and rice flour, and konjac glucomannan concentration on noodle analogue characteristics. Konjac glucomannan was added at different concentrations (3%, 4%, 5%) to different ratios of sorghum-rice flours (50:50, 25:75, 0:100). Results showed that the best formulation was a noodle analogue made with a 25:75 sorghum-rice flour ratio and 4% konjac glucomannan. The best-formulated noodle analogue had a higher moisture content (13.35±0.38%), higher fat, and higher carbohydrate (71.93±0.11%), but lower protein and ash content than the commercial wheat-based noodle. It also had a lower starch (60.43%) and dietary fibre content (10.34%), higher cooking loss (9.44±0.60%), and lower water absorption (176.45±4.86%) compared to commercial wheat-based noodle. In terms of textural and mechanical properties, the best-formulated noodle analogue had lower hardness, higher adhesiveness, lower springiness, lower cohesiveness, lower tensile strength, and lower elongation. However, the multiple comparison test showed that panellists perceived the best-formulated noodle analogue to be comparable to commercial wheat-based noodle, in terms of aroma, chewiness, hardness, and adhesiveness.
Effect of edible coating sodium alginate with addition of siam pontianak tangerine peel essential oil (Citrus suhuinensis cv Pontianak) on the physical quality of strawberries (Fragaria ananassa) during refrigeration temperature storage
Authors: Utami Rohula , Annisa Rifka Ratna , Praseptiangga Danar , Nursiwi Asri , Sari Ardhea Mustika , Ashari Hasim , Ikarini Imro’ah , Hanif Zainuri
Published: June 2023

Strawberry (Fragaria sp.) is a subtropical fruit from Chile, South America. Strawberries are liked because of their uniqueness, attractive colors and shapes, distinctive aroma, and fresh taste. Strawberries are a non-climacteric fruit that has a relatively short shelf life. Damage to horticultural products can be caused mechanically, physiologically, and microbiologically. The edible coating has been a popular preservation method in recent years because it effectively extends the post-harvest shelf life of fresh products such as soft-textured fruits. This research was conducted to determine the effect of the concentration of Siam Pontianak tangerine peel (Citrus suhuinensis cv Pontianak) essential oil which was incorporated into an edible coating based on sodium alginate on the quality of strawberries in terms of physical characteristics (colors, hardness, total dissolved solids, weight loss). The edible coating based on sodium alginate with different concentrations of Siam Pontianak tangerine peel essential oil significantly affected the quality of strawberries on all parameters, including color, hardness, total dissolved solids, and weight loss during refrigeration temperature storage.
Modelling capture efficiency of single-cell RNA-sequencing data improves inference of transcriptome-wide burst kinetics
Authors: Tang Wenhao , Jørgensen Andreas Christ Sølvsten , Marguerat Samuel , Thomas Philipp , Shahrezaei Vahid
Published: June 2023

Motivation

Gene expression is characterized by stochastic bursts of transcription that occur at brief and random periods of promoter activity. The kinetics of gene expression burstiness differs across the genome and is dependent on the promoter sequence, among other factors. Single-cell RNA sequencing (scRNA-seq) has made it possible to quantify the cell-to-cell variability in transcription at a global genome-wide level. However, scRNA-seq data are prone to technical variability, including low and variable capture efficiency of transcripts from individual cells.

Results

Here, we propose a novel mathematical theory for the observed variability in scRNA-seq data. Our method captures burst kinetics and variability in both the cell size and capture efficiency, which allows us to propose several likelihood-based and simulation-based methods for the inference of burst kinetics from scRNA-seq data. Using both synthetic and real data, we show that the simulation-based methods provide an accurate, robust and flexible tool for inferring burst kinetics from scRNA-seq data. In particular, in a supervised manner, a simulation-based inference method based on neural networks proves to be accurate and useful when applied to both allele and nonallele-specific scRNA-seq data.

Availability and implementation

The code for Neural Network and Approximate Bayesian Computation inference is available at https://github.com/WT215/nnRNA and https://github.com/WT215/Julia_ABC, respectively.
enviRule: an end-to-end system for automatic extraction of reaction patterns from environmental contaminant biotransformation pathways
Authors: Zhang Kunyang , Fenner Kathrin
Published: June 2023

Motivation

Transformation products (TPs) of man-made chemicals, formed through microbially mediated transformation in the environment, can have serious adverse environmental effects, yet the analytical identification of TPs is challenging. Rule-based prediction tools are successful in predicting TPs, especially in environmental chemistry applications that typically have to rely on small datasets, by imparting the existing knowledge on enzyme-mediated biotransformation reactions. However, the rules extracted from biotransformation reaction databases usually face the issue of being over/under-generalized and are not flexible to be updated with new reactions.

Results

We developed an automatic rule extraction tool called enviRule. It clusters biotransformation reactions into different groups based on the similarities of reaction fingerprints, and then automatically extracts and generalizes rules for each reaction group in SMARTS format. It optimizes the genericity of automatic rules against the downstream TP prediction task. Models trained with automatic rules outperformed the models trained with manually curated rules by 30% in the area under curve (AUC) scores. Moreover, automatic rules can be easily updated with new reactions, highlighting enviRule’s strengths for both automatic extraction of optimized reactions rules and automated updating thereof.

Availability and implementation

enviRule code is freely available at https://github.com/zhangky12/enviRule.
Primary entry trocar design and entry-related complications at laparoscopy in obese patients: meta-analysis
Authors: Miti Chimwemwe , Busuulwa Paula , Scott Richard , Bloomfield-Gadelha Hermes
Published: June 2023

Background

Safe primary entry at laparoscopy could present challenges in obese patients. Various techniques have been proposed in previous studies, however, the characteristics of the actual device utilized may be more influential than the technique in achieving successful abdominal entry in patients with increased BMI.

Methods

This systematic review and meta-analysis included both randomized and non-randomized studies gathered with no date filters from MEDLINE, Embase, Scopus, Web of Science and Clinicaltrials.gov. PRISMA guidelines underpinned the conduct and reporting of the review. The meta-analysis of proportions was conducted using a generalized linear mixed model and analyses included random-effects models. The primary outcome was the proportion of first access vascular and visceral injuries incurred in the process of laparoscopic abdominal surgery in patients with a BMI >30 kg/m2. Subgroup analysis was performed for optical versus non-optically enabled devices.

Results

In total, 5403 patients were analysed across 13 observational studies with a mean BMI of 45.93 kg/m2. In 216 patients from two randomized studies, the mean BMI was 39.92 kg/m2. The overall incidence using a random-effects model was 8.1 per 1000 events of visceral and vascular injuries (95 per cent c.i. 0.003 to 0.024). Heterogeneity was statistically significant at I2 = 80.5 per cent (69.6 per cent; 87.5 per cent, P< 0.0001). In a subgroup analysis, a tendency towards reduced injuries when optical devices were employed was observed with one per 100 injuries in these trocars (95 per cent c.i. 0.001 to 0.018) versus four per 100 (95 per cent c.i. −0.019 to –0.102) in non-optically enabled devices.

Conclusion

Injuries during primary laparoscopic entry undertaken in obese patient groups are uncommon. Due to considerable heterogeneity in the small number of examined studies, evidence was insufficient and largely of low quality to ascribe differences in the incidence of injuries to the characteristics of the primary entry trocar utilized.
Gambling Harms in Adult Social Care: Developing an ‘Introductory’ Question to Identify Gambling Harms Among Service Users
Authors: Forward Cat , Norrie Caroline , Bramley Stephanie , Riley Liz , Shearer James , Finch Emily , Stewart Glenn , Fletcher Paul , Manthorpe Jill , Wardle Heather
Published: June 2023

Gambling harms are disproportionately experienced among disadvantaged groups and as such, adult social care (ASC) practitioners are well-placed to identify and support affected individuals. There exists no evidence-based ‘introductory’ question for practitioners to identify those at risk of gambling harms, which includes family and friends (‘affected others’). To develop an ‘introductory’ question for use in English ASC, we conducted a scoping review that identified fifteen potential questions. Questions were refined through expert panel review groups (n = 13), cognitive interviewing (n = 18), test–retest reliability checks (n = 20) and validity testing (n = 2,100) against gold-standard measures of problem gambling behaviour. The question development process produced two questions suitable for testing in local authority (LA) ASC departments. These were (i) ‘Do you feel you are affected by any gambling, either your own or someone else’s?’ and (ii) ‘If you or someone close to you gambles, do you feel it is causing you any worries?’ Each had good face validity, strong test–retest reliability, correlated highly with well-being measures and performed reasonably against validated measures of problem gambling. These two questions are currently being piloted by ASC practitioners in three English LAs to assess their feasibility for adoption in practice.
CSF proteomics in autosomal dominant Alzheimer’s disease highlights parallels with sporadic disease
Authors: van der Ende Emma L , In ‘t Veld Sjors G J G , Hanskamp Iris , van der Lee Sven , Dijkstra Janna I R , Hok-A-Hin Yanaika S , Blujdea Elena R , van Swieten John C , Irwin David J , Chen-Plotkin Alice , Hu William T , Lemstra Afina W , Pijnenburg Yolande A L , van der Flier Wiesje M , del Campo Marta , Teunissen Charlotte E , Vermunt Lisa
Published: June 2023

Autosomal dominant Alzheimer’s disease (ADAD) offers a unique opportunity to study pathophysiological changes in a relatively young population with few comorbidities. A comprehensive investigation of proteome changes occurring in ADAD could provide valuable insights into AD-related biological mechanisms and uncover novel biomarkers and therapeutic targets. Furthermore, ADAD might serve as a model for sporadic AD, but in-depth proteome comparisons are lacking. We aimed to identify dysregulated CSF proteins in ADAD and determine the degree of overlap with sporadic AD. We measured 1472 proteins in CSF of PSEN1 or APP mutation carriers (n = 22) and age- and sex-matched controls (n = 20) from the Amsterdam Dementia Cohort using proximity extension-based immunoassays (PEA). We compared protein abundance between groups with two-sided t-tests and identified enriched biological pathways. Using the same protein panels in paired plasma samples, we investigated correlations between CSF proteins and their plasma counterparts. Finally, we compared our results with recently published PEA data from an international cohort of sporadic AD (n = 230) and non-AD dementias (n = 301). All statistical analyses were false discovery rate-corrected. We detected 66 differentially abundant CSF proteins (65 increased, 1 decreased) in ADAD compared to controls (q < 0.05). The most strongly upregulated proteins (fold change >1.8) were related to immunity (CHIT1, ITGB2, SMOC2), cytoskeletal structure (MAPT, NEFL) and tissue remodelling (TMSB10, MMP-10). Significant CSF-plasma correlations were found for the upregulated proteins SMOC2 and LILR1B. Of the 66 differentially expressed proteins, 36 had been measured previously in the sporadic dementias cohort, 34 of which (94%) were also significantly upregulated in sporadic AD, with a strong correlation between the fold changes of these proteins in both cohorts (rs = 0.730, P < 0.001). Twenty-nine of the 36 proteins (81%) were also upregulated among non-AD patients with suspected AD co-pathology. This CSF proteomics study demonstrates substantial biochemical similarities between ADAD and sporadic AD, suggesting involvement of the same biological processes. Besides known AD-related proteins, we identified several relatively novel proteins, such as TMSB10, MMP-10 and SMOC2, which have potential as novel biomarkers. With shared pathophysiological CSF changes, ADAD study findings might be translatable to sporadic AD, which could greatly expedite therapy development.
Pleural Empyema Caused by Streptococcus intermedius and Fusobacterium nucleatum: A Distinct Entity of Pleural Infections
Authors: Dyrhovden Ruben , Eagan Tomas Mikal , Fløtten Øystein , Siljan William , Leegaard Truls Michael , Bø Bjørnar , Fardal Hilde , Grøvan Fredrik , Kildahl-Andersen Arne , Larssen Kjersti Wik , Tilseth Rune , Hjetland Reidar , Løes Sigbjørn , Lindemark Frode , Tellevik Marit , Breistein Rebecca , Kommedal Øyvind
Published: June 2023

Background

Many community-acquired pleural infections are caused by facultative and anaerobic bacteria from the human oral microbiota. The epidemiology, clinical characteristics, pathogenesis, and etiology of such infections are little studied. The aim of the present prospective multicenter cohort study was to provide a thorough microbiological and clinical characterization of such oral-type pleural infections and to improve our understanding of the underlying etiology and associated risk factors.

Methods

Over a 2-year period, we included 77 patients with community-acquired pleural infection, whereof 63 (82%) represented oral-type pleural infections. Clinical and anamnestic data were systematically collected, and patients were offered a dental assessment by an oral surgeon. Microbial characterizations were done using next-generation sequencing. Obtained bacterial profiles were compared with microbiology data from previous investigations on odontogenic infections, bacteremia after extraction of infected teeth, and community-acquired brain abscesses.

Results

From the oral-type pleural infections, we made 267 bacterial identifications representing 89 different species. Streptococcus intermedius and/or Fusobacterium nucleatum were identified as a dominant component in all infections. We found a high prevalence of dental infections among patients with oral-type pleural infection and demonstrate substantial similarities between the microbiology of such pleural infections and that of odontogenic infections, odontogenic bacteremia, and community-acquired brain abscesses.

Conclusions

Oral-type pleural infection is the most common type of community-acquired pleural infection. Current evidence supports hematogenous seeding of bacteria from a dental focus as the most important underlying etiology. Streptococcus intermedius and Fusobacterium nucleatum most likely represent key pathogens necessary for establishing the infection.
Repair of mitral prolapse: comparison of thoracoscopic minimally invasive and conventional approaches
Authors: Ascaso María , Sandoval Elena , Muro Anna , Barriuso Clemente , Quintana Eduard , Alcocer Jorge , Sitges Marta , Vidal Bàrbara , Pomar José-Luis , Castellà Manuel , García-Álvarez Ana , Pereda Daniel
Published: June 2023

OBJECTIVES

Surgical repair remains the best treatment for severe primary mitral regurgitation (MR). Minimally invasive mitral valve surgery is being increasingly performed, but there is a lack of solid evidence comparing thoracoscopic with conventional surgery. Our objective was to compare outcomes of both approaches for repair of leaflet prolapse.

METHODS

All consecutive patients undergoing surgery for severe MR due to mitral prolapse from 2012 to 2020 were evaluated according to the approach used. Freedom from mortality, reoperation and recurrent severe MR were evaluated by Kaplan–Meier method. Differences in baseline characteristics were adjusted with propensity score-matched analysis (1:1, nearest neighbour).

RESULTS

Three hundred patients met inclusion criteria and were divided into thoracoscopic (N = 188) and conventional (sternotomy; N = 112) groups. Unmatched patients in the thoracoscopic group were younger and had lower body mass index, New York Heart Association class and EuroSCORE II preoperatively. After matching, thoracoscopic group presented significantly shorter mechanical ventilation (9 vs 15 h), shorter intensive care unit stay (41 vs 65 h) and higher postoperative haemoglobin levels (11 vs 10.2 mg/dl) despite longer bypass and cross-clamp times (+30 and +17 min). There were no differences in mortality or MR grade at discharge between groups nor differences in survival, repair failures and reinterventions during follow-up.

CONCLUSIONS

Minimally invasive mitral repair can be performed in the majority of patients with mitral prolapse, without compromising outcomes, repair rate or durability, while providing shorter mechanical ventilation and intensive care unit stay and less blood loss.
Natural history of non-functioning pituitary microadenomas: results from the UK non-functioning pituitary adenoma consortium
Authors: Hamblin Ross , Fountas Athanasios , Lithgow Kirstie , Loughrey Paul Benjamin , Bonanos Efstathios , Shinwari Shah Khalid , Mitchell Kirsten , Shah Syed , Grixti Lydia , Matheou Mike , Isand Kristina , McLaren David S , Surya Ashutosh , Ullah Hafiz Zubair , Klaucane Katarina , Jayasuriya Anuradha , Bhatti Sumbal , Mavilakandy Akash , Ahsan Masato , Mathew Susan , Hussein Ziad , Jansz Thijs , Wunna Wunna , MacFarlane James , Ayuk John , Abraham Prakash , Drake William M , Gurnell Mark , Brooke Antonia , Baldeweg Stephanie E , Sam Amir H , Martin Niamh , Higham Claire , Reddy Narendra , Levy Miles J , Ahluwalia Rupa , Newell-Price John , Vamvakopoulos Joannis , Krishnan Amutha , Lansdown Andrew , Murray Robert D , Pal Aparna , Bradley Karin , Mamoojee Yaasir , Purewal Tejpal , Panicker Janki , Freel E Marie , Hasan Faisal , Kumar Mohit , Jose Biju , Hunter Steven J , Karavitaki Niki
Published: June 2023

Objective

The optimal approach to the surveillance of non-functioning pituitary microadenomas (micro-NFPAs) is not clearly established. Our aim was to generate evidence on the natural history of micro-NFPAs to support patient care.

Design

Multi-centre, retrospective, cohort study involving 23 endocrine departments (UK NFPA consortium).

Methods

Clinical, imaging, and hormonal data of micro-NFPA cases between January, 1, 2008 and December, 21, 2021 were analysed.

Results

Data for 459 patients were retrieved [median age at detection 44 years (IQR 31-57)—152 males/307 females]. Four hundred and nineteen patients had more than two magnetic resonance imagings (MRIs) [median imaging monitoring 3.5 years (IQR 1.71-6.1)]. One case developed apoplexy. Cumulative probability of micro-NFPA growth was 7.8% (95% CI, 4.9%-8.1%) and 14.5% (95% CI, 10.2%-18.8%) at 3 and 5 years, respectively, and of reduction 14.1% (95% CI, 10.4%-17.8%) and 21.3% (95% CI, 16.4%-26.2%) at 3 and 5 years, respectively. Median tumour enlargement was 2 mm (IQR 1-3) and 49% of micro-NFPAs that grew became macroadenomas (nearly all >5 mm at detection). Eight (1.9%) patients received surgery (only one had visual compromise with surgery required >3 years after micro-NFPA detection). Sex, age, and size at baseline were not predictors of enlargement/reduction. At the time of detection, 7.2%, 1.7%, and 1.5% patients had secondary hypogonadism, hypothyroidism, and hypoadrenalism, respectively. Two (0.6%) developed hypopituitarism during follow-up (after progression to macroadenoma).

Conclusions

Probability of micro-NFPA growth is low, and the development of new hypopituitarism is rare. Delaying the first follow-up MRI to 3 years and avoiding hormonal re-evaluation in the absence of tumour growth or clinical manifestations is a safe approach for micro-NFPA surveillance.
Migraine and cardiovascular disease: what cardiologists should know
Authors: Kalkman Deborah N , Couturier Emile G M , El Bouziani Abdelhak , Dahdal Jorge , Neefs Jolien , Woudstra Janneke , Vogel Birgit , Trabattoni Daniela , MaassenVanDenBrink Antoinette , Mehran Roxana , de Winter Robbert J , Appelman Yolande
Published: June 2023

Migraine is a chronic neurovascular disease with a complex, not fully understood pathophysiology with multiple causes. People with migraine suffer from recurrent moderate to severe headache attacks varying from 4 to 72 h. The prevalence of migraine is two to three times higher in women compared with men. Importantly, it is the most disabling disease in women <50 years of age due to a high number of years lived with disability, resulting in a very high global socioeconomic burden. Robust evidence exists on the association between migraine with aura and increased incidence of cardiovascular disease (CVD), in particular ischaemic stroke. People with migraine with aura have an increased risk of atrial fibrillation, myocardial infarction, and cardiovascular death compared with those without migraine. Ongoing studies investigate the relation between migraine and angina with non-obstructive coronary arteries and migraine patients with patent foramen ovale. Medication for the treatment of migraine can be preventative medication, such as beta-blockers, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, antiepileptics, antidepressants, some of the long-acting calcitonin gene-related peptide receptor antagonists, or monoclonal antibodies against calcitonin gene-related peptide or its receptor, or acute medication, such as triptans and calcitonin gene-related peptide receptor antagonists. However, these medications might raise concerns when migraine patients also have CVD due to possible (coronary) side effects. Specifically, knowledge gaps remain for the contraindication to newer treatments for migraine. All cardiologists will encounter patients with CVD and migraine. This state-of-the-art review will outline the basic pathophysiology of migraine and the associations between migraine and CVD, discuss current therapies, and propose future directions for research.