bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the influence of pendulum convex plate on the partial value of quartz flexible accelerometer
Authors: Jiayue Zhang , Hong Liu , Yuchao Hao
Published: May 2024

The partial value is an essential performance index for assessing the stability of quartz flexible accelerometers. By analyzing the structure of the quartz flexural accelerometer and the impact of the pendulum convex plate, the influence of the convex plate on the partial value of the accelerometer is studied by theoretical derivation and modeling simulation methods. The results show that the barycentric coordinate shifts by approximately 10.7678 × 10-12
µm with the change of the coplanarity of the convex plate, which causes mechanical zero position errors, increases the partial value, and affects the stability of the quartz flexural accelerometer. Therefore, the coplanarity of the convex plate should be maintained at ≤0.3 µm and the partial value should be within the error range of ≤ |±2| mg and provide improvement measures to establish a basis for further improving the stability of the quartz flexible accelerometer.
Analysis of aerodynamic and stealth characteristics of aircraft under the action of microwave plasma
Authors: Wu Xinyi , Zhang Yujian , Tian Deyang , Wu Changju , Zhou Jie , Zhu Yunliang
Published: May 2024

This paper investigates the impact of plasma on the aerodynamic and stealth characteristics of hypersonic aircraft. Utilizing the finite volume method, the governing equations of the fluid mechanics were discretized, and the seven-element air chemical reaction model was employed for computations. A technique involving the alteration of the chemical reaction source term rate was employed to replicate the actual plasma concentration distortion phenomena induced by microwaves around hypersonic vehicles, enabling an analysis of the influence of plasma density distortion on the aerodynamic characteristics of these vehicles. In addition, the method of Piecewise Linear JE Recursive Convolution Finite-difference Time-domain (PLJERC-FDTD) is used to calculate the radar scattering cross-section of the target within both the initial and distorted flow fields. This allowed an examination of the variation in the aircraft’s stealth characteristics when exposed to distortion in an ionized environment.
Active control and prediction model for the dynamic shape of laminated plate/shell structures with piezoelectric actuators
Authors: Zheng Hao , Wang Hongfu , Zhou Qiang , Li Jingjing , Huang Junsong , Wang Baichuan , Liu Xiaorang , Yin Guochuan
Published: May 2024

This study establishes an active control and prediction model for the dynamic shape of laminated plates/shells with piezoelectric actuators. Firstly, transient responses of shell structures are numerically calculated by adopting the finite element method (FEM) and the Newmark formulae, then the Kuhn-Tucker equation is utilized to get the time-varying voltage values with a minimum shape control error. Subsequently, a backpropagation neural network (BPNN) is constructed to predict the control precision for cases with different piezoelectric actuator layouts. Finally, the proposed control model is demonstrated through numerical examples with a maximum relative control error of only 0.023% for a given desired shape and the average error of the prediction model with 98 input neurons is 18%, thereby satisfying the application requirements. Furthermore, for a model with 3870 degrees of freedom and 21 discrete time points, the computational time is reduced significantly from 8.24 s to 0.002 s through the prediction model, making it highly suitable for optimization problems by utilizing heuristic algorithms.
Design and verification of controller for a small coaxial dual-rotor aircraft
Authors: Gao Botao , Wu Zhilin , Wu Mingjian , Li Shuang
Published: May 2024

In recent years, coaxial dual-rotor aircraft has attracted much attention due to its unique aerodynamic layout. However, it is difficult to miniaturize the coaxial dual-rotor aircraft that relies on the principle of periodic pitch variation due to complex structure and control difficulties. This study proposes a small cylindrical coaxial dual-rotor aircraft based on a vector motor seat. For the control problems of such coaxial dual-rotor aircraft, a position and attitude controller based on neural networks and adaptive cascaded PID control is designed. A control system model was established and tested using MATLAB/Simulink. The proposed control scheme’s soundness and efficiency were confirmed by creating a prototype and performing flight trials. The results show that compared with the classic PID controller, the control effect of the controller has improved by 36.3% to 54.6%. In the centripetal rotation flight simulation experiment, the displacement error does not exceed 0.2 m, the speed error does not exceed 0.05 m/s, and the attitude angle error does not exceed 0.01 rad. This validates the effectiveness of the designed controller, indicating that the controller can enhance the stability of the system and achieve stable hovering and flight.
Analysis of aerodynamic characteristics of flexible flapping wings mimicking hummingbirds
Authors: Xia Meng
Published: May 2024

Over hundreds of millions of years of natural selection, hummingbirds have evolved excellent flight characteristics. This ingenious wing structure provides a new inspiration for the design of bionic flapping wings. In this paper, a kind of bionic flexible flapping wing is designed with a hummingbird as the prototype, its parametric aerodynamic characteristics are analyzed, and its feasibility is verified by simulation. Combined with the simulation results, the aerodynamic parameters such as lift, drag, and lift-drag ratio are comprehensively considered, and the optimal parameter combination is 5 m/s-20 Hz. Under this parameter combination, the aerodynamic performance is the best, and the lift-drag ratio is as high as 13.3. This paper can provide a theoretical basis and technical reference for further development of bionic flapping wing MAV design.
Design optimization of a low-cost three-stage launch vehicle with modular hybrid rocket motors
Authors: Wenzhi Hao , Hao Zhu , Wei He , Zhiguo Zhang
Published: May 2024

This article investigates the impact of modular propulsion system design on the performance and cost of a three-stage hybrid rocket. Furthermore, it conducts a multi-objective optimization of unit payload cost, take-off mass, and payload mass ratio, considering factors such as the number of motors and layout considerations. The optimization design scheme for the three-stage hybrid rocket is divided into four cases. In the first case, each stage is equipped with a fixed single motor, and each stage is independently optimized without modular design. The second case considers the use of multiple motors in the first and second stages, still without modular design. The third case also involves multiple motors in the first and second stages, but all motors in each stage have identical parameters except for the nozzle expansion ratio, implementing a modular design. In the fourth case, the number and layout of the motor design method are the same as those in the third case, with independent optimization in the third stage using partial modular design. The results indicate that the unit payload cost of the multi-motor non-modular design case can be reduced by 13.12% compared to the single-motor non-modular design case. Within the modular case, the full modular design case is slightly inferior to the partial modular design case. Based on the above data, it can be concluded that the first and second stages of modular rockets offer the best performance and the lowest cost.
Sensitivity analysis of aircraft structural fatigue reliability under mixed uncertainty
Authors: Liu Shiyu
Published: May 2024

Fatigue is the main failure mode of the structure. The aircraft structure is subject to multi-level cyclic loading, which is prone to fatigue damage, reduces reliability, and affects flight safety. Various uncertainties are inevitably associated with the factors related to the fatigue performance of the structure. In particular, for the variables with insufficient information, their uncertainties are hard to describe by the probability density function. In this paper, these variables are treated as interval variables. The sensitivity analysis of the aircraft structure fatigue reliability model under mixed uncertainties is studied. On the basis of the definition of the distance between interval numbers, the interval distance indexes are proposed as a global sensitivity measure for a mixed random-interval model system. To reduce the computational cost, the method combining the space partition with unscented transformation (SP-UT) is used to calculate the proposed indexes. Lastly, the proposed indexes and method are applied to solve the aircraft structure fatigue problem. Compared with the traditional MCS method, the proposed method has proved to be more conducive and efficient.
Research on high power and heat flux aerospace electronic products of integrated thermal conduction technology
Authors: Wang Minghe , Guo Qingyuan , Wang Xinghai , Zhu Qixing , Zhu Yufeng , Tang Wei
Published: May 2024

In response to the increasing demand for enhanced computational capabilities within satellite systems, there has been a simultaneous rise in the heat flux density of onboard electronic components. The thermal output of these components has significantly increased compared to traditional satellite processing electronics, leading to a concurrent elevation in the heat flux density related to processing chips and the surfaces accommodating equipment installations. This paper establishes a model for conduction heat dissipation in aviation electronic products. The outlined calculation methodology facilitates a preliminary assessment of the system’s heat dissipation capacity. The article further examines the inherent heat dissipation capabilities in two commonly employed structural configurations. Additionally, it introduces an integrated design approach for structural heat dissipation, including experimental considerations and validation outcomes. The assessment methodologies and design principles detailed in this article are particularly relevant and applicable to the thermal design imperatives associated with high-power electronic products deployed for the extended operational durations typical of spacecraft.
Experimental research on blowing-rain intensity and uniformity of rain tunnel for aircraft rain removal testing
Authors: Liu Qianqian , Zhao Yi , Liu Caixia
Published: May 2024

The objective of the present study is to characterize a rain tunnel that is used for performance testing of aircraft windshield rain removal systems. The rain tunnel in the present study is an open jet wind tunnel with six full cone pressure swirl nozzles arranged at its outlet. Experiments are conducted with water at room temperature as the working medium. The influence of total water supply flow rate and air velocity on the blowing-rain intensity and uniformity is studied. The total water supply flow rate varies from 0.57 m3/h to 1.03 m3/h, while the pressure at the inlet of the nozzle ranges from 1.44 bar to 6.52 bar. The air velocity of 30 m/s, 40 m/s, and 50 m/s is studied. A special test setup has been designed for measurements of the blowing-rain intensity and uniformity. Experimental results indicate that the blowing-rain intensity and uniformity both increase with the increasing total water supply flow rate and decrease with the increasing air velocity.
Rotating heat pipe model based on lumped parameter method
Authors: Wu Chang , Zeng Yu , Sun Hai , Yang Gang
Published: May 2024

On the basis of many theoretical studies about rotating heat pipes, a simplified mathematical model is established based on the lumped parameter method, ignoring the temperature difference inside each section of the heat pipe is ignored, and comparing the calculated results with the experimental data. It is identified that this model has a good applicability at high speeds and low liquid filling rates, and effectively reduces the amount of calculation, which is of practical significance to the engineering application of rotating heat pipes.
A composite planning method considering avoidance of multiple no-fly zones
Authors: He Mingyong , Nan Ying
Published: May 2024

Aiming at the problem that multiple no-fly zones need to be avoided in the reentry process of aircraft, a composite programming method combining conjugate gradient and dynamic programming is proposed. The method divides the reentry flight trajectory into two parts: the longitudinal plane and the transverse plane. The longitudinal plane uses the conjugate gradient method to guide the aircraft to meet the minimum mass of the thermal protection system during the whole flight. The horizontal plane mainly uses the dynamic programming method to obtain a reasonable obstacle avoidance route and inversely calculates the change law of the heading angle. The simulation results show that the three-dimensional reentry trajectory can reasonably solve the problem of avoiding multiple no-fly zones and meeting the aerodynamic constraints of the flight process.
Rolling active load relief technology for launch vehicle bundled with common booster core in face
Authors: He Mianchao , Liu Yuxi , Zhang Zhiping , Sheng Yinghua
Published: May 2024

The aerodynamic interference forces and moments of different windward surfaces of a launch vehicle bundled with a common booster core in the face vary considerably. The servo mechanism is laid out to maximize the control capability of the rocket at a certain angle. The dominant surface of the rocket is determined by aerodynamic interference and control capability. For the problem of large interference and asymmetry during the flight of a nominal rocket, a rolling active load relief control law based on the optimization of the spatial interference vector is proposed. The direction with the largest spatial interference vector is obtained online by visual acceleration information. By adjusting the rolling program angle, the rocket will align the dominant face with the direction of the largest interference when flying through the windy area. And then, the rocket obtains a good control effect. The simulation results show that the control law proposed in this paper can effectively improve the adaptability of the rocket control in the case of sudden changes in wind direction. It achieves the purpose of reducing the static load of the rocket body structure during the flight.
Research on fault-tolerant control methods for Bi-rotor vehicles under actuator failure
Authors: Sun Xue , Wang Donghui , Zhan Zhengyong , Cui Yuwei
Published: May 2024

A PID-self-impedance fault-tolerant controller based on the inner and outer loop structure is developed for a new form of bi-rotor vehicle, taking into account the fault-tolerant control problem when the actuator fails. First, the dynamics model and actuator fault model of the bi-rotor vehicle are established, the PID active fault-tolerant controller with control parameter switching is selected for the outer loop, and the self-immune controller is selected for the inner loop. Second, when a fault occurs, the outer loop PID controller’s settings are switched to the controller parameters of the relevant fault state based on the extent of the fault, and the parameters are matched with the robust controller of the inner loop to achieve fault-tolerant control. Finally, simulation experiments show that the designed fault-tolerant controller can still achieve stable tracking of position and attitude in the presence of actuator faults. This indicates that the flight control system is robust to fault-induced disturbances and effectively improves the vehicle’s fault-tolerant performance.
Trajectory planning and control strategy optimization design of double electric cylinder erecting device
Authors: Liu Dong , Zong Xiaorui , Zhao Yu , Jiang Zhen , Cheng Dong
Published: May 2024

The transition of the rocket from a horizontal to an erect state before its launch on the offshore platform is a crucial stage. Compared with erecting the rocket on the ground, higher servo control and synchronization accuracy are required for erecting it on the offshore platform. Most rocket erecting devices on offshore platforms rely on hydraulic drive systems, posing challenges due to their lower servo control accuracy and difficulties in achieving high-precision synchronization. The erecting process, trajectory planning, control system, and control strategies of rockets driven by a double electric cylinder erecting device are studied, aiming at the requirement of erecting rocket devices on offshore platforms. This paper commences by establishing the kinematic model of erecting the rocket with a double electric cylinder erecting device. It delves into the process and trajectory of the erection rocket with a double electric cylinder erecting device. Subsequently, the focus shifts toward designing the control system, while inclination and angular velocity sensors monitor the erection process. Finally, designing and demonstrating control strategies for a double electric cylinder erecting device, three different control strategies, master control, master-slave control, and cross-coupling control, are analyzed, and the cross-coupling control strategy is selected as the control strategy of the double electric cylinder offshore platform rocket erecting device.
Research on the cabin pressure control system based on the gray wolf fuzzy PID algorithm
Authors: Wang Shun , Meng Fanxing , Yang Yonghui , Yang Changbao
Published: May 2024

The cabin pressure control system is typically nonaffine-nonlinear time-varying system. In this paper, the fuzzy PID control method optimized by gray wolf algorithm is proposed to solve the problems of large overshoot and long adjustment times in traditional control methods. Simulation results show that the fuzzy PID control method optimized by gray wolf algorithm proposed in this paper improves the dynamic characteristics of the system, reduces cabin pressure error and adjustment time, stabilizes the control process, and improves the comfortableness of passengers.
A Method for micro-vibration test analysis of small satellites with laser loading
Authors: Zhang Yousheng
Published: May 2024

Based on the parameters of the structure configuration and equipment layout of a small laser satellite in the design stage, the in-orbit micro-vibration simulation analysis of the satellite is carried out by finite element method, which mainly includes [1-2]: 1) modal analysis obtaining the main vibration frequency and modal shape of the satellite in orbit; 2) micro-vibration analysis of the satellite in orbit with the micro-vibration disturbance of the moment gyroscope as the excitation condition. Through the in-orbit micro-vibration simulation analysis of the satellite, we can obtain the vibration transmission relationship from the moment gyroscope to the laser communication load and the micro-vibration state of the laser communication load.
Analysis and study of maximum allowable turning speed for civil aircraft
Authors: Feng Kai , Pan Lijun , Zhao Da , Jin Ding
Published: May 2024

The maximum allowable turning speed of an aircraft is a critical factor affecting the safety of civil aviation. Evaluating the maximum permissible taxiing turn speed for civil aircraft is an essential aspect of aircraft design. To ensure that the aircraft does not experience unbalanced forces leading to a lateral rollover due to excessive taxiing speed, an engineering estimation method is employed to study the maximum permissible taxiing turn speed for civil aircraft. This method begins with certain assumptions and calculation scenarios, followed by the derivation of a calculation model based on the analysis of aircraft forces. Lastly, a case study of a specific aircraft’s maximum taxiing turn speed is conducted in conjunction with practical engineering considerations. The study reveals that as crosswind forces on civil aircraft increase, the maximum turning speed decreases. Moreover, for lighter aircraft with a forward center of gravity, the risk of lateral rollovers is higher. These findings underscore the engineering applicability of the estimation method.
Predefined-time prescribed performance guidance law design against maneuvering target under input saturation
Authors: Wei Zhenyan , Li Jianfeng , You Weishuai , Song Shenmin , Shi Xiaoping
Published: May 2024

A novel SMC-based prescribed performance guidance law combined with a base generator (TBG) is proposed. A TBG-based modified Lyapunov function is first proposed, which ensures that the LOS tracking error converges into zero within a predefined time. A novel sliding manifold with adjusting convergent time property is proposed, which brings about a smaller control magnitude and predefined time convergent rate. To ensure a satisfied transit and steady performance, some converted variables are defined based on which a novel prescribed performance guidance law is constructed. The input saturation problem is properly solved by designing a novel TBG-based one-order auxiliary system. Extensive simulation results have verified the effectiveness of the proposed method.
Attitude consensus coordination algorithm for spacecraft formation under compound disturbance
Authors: Zhang Yunxiao , Chen Chuanzhi , Zhang Yingxue , Yu Hongzhi , deng Xiaokang
Published: May 2024

To address the attitude coordination and consensus tracking problem in the multi-spacecraft system, a distributed attitude-coordinated strategy based on the Fixed-time theory is proposed. An observer based on second-order integral sliding mode is designed to accurately estimate the compound disturbance, which consists of external disturbance and inertia uncertainties. On the basis of the observed information, a distributed Fixed-time attitude coordination controller is proposed, which can guarantee the attitude tracking errors converge to zero in a fixed time. System stability is analyzed by using the Lyapunov function. Finally, simulations and comparison analysis demonstrate the effectiveness and superiority of the proposed control scheme.
Research on asymmetric spatial heterodyne spectroscopy for velocimetry navigation
Authors: Gao Yiwei , Wang Qiansheng , Cui Wenxin , Li Zhiwei , Luo Haiyan , Xiong Wei
Published: May 2024

The further development of deep space exploration contributes to the exploration of the universe and the origin and evolution of life on Earth, and is a prerequisite and foundation for the development and utilization of space resources. Autonomous navigation of deep space probes, one of the key technologies for deep space exploration, can significantly reduce ground support costs and improve the autonomous operation, management, and on-orbit survivability of deep space probes. Among them, autonomous astronomical navigation methods based on velocity measurements directly measure velocity information, effectively avoiding the impact of using calculus to solve velocity on response time and navigation accuracy in navigation methods based on angle and distance measurements. The passive radial velocity measurement technique of asymmetric spatial heterodyne spectroscopy has the advantages of compact structure, large luminous flux, and multiple spectra detected simultaneously. Taking the Sun as the navigation target source, we carried out the selection of observational spectral lines and the parameter design of the velocimetry navigation system, designed the calculation of phases for the absorption characteristic line under the complex polychromatic strong background, carried out the simulation analysis of velocimetry under the typical relative velocimetry.
Relative positioning method for unmanned aerial vehicles in complex electromagnetic environment
Authors: Yu Dongming , Liu Hong
Published: May 2024

In view of the problem that satellite navigation and positioning systems may fail or be unreliable in complex electromagnetic environments, which may lead to divergence of UAV positioning, the inertial navigation systems working for a long time may lead to increasing errors. This paper adopts a relative navigation algorithm that combines airborne inertial navigation systems and inter-aircraft relative information measurement. The algorithm requires each UAV to load relative navigation equipment and inertial navigation systems and acquire and fuse relative navigation information through inter-aircraft communication. In this relative navigation algorithm, the host and wing plane can transmit their respective navigation information and relative navigation information to each other, and fuse information from different sources through a Kalman filtering algorithm to enhance the accuracy of relative positioning data. With the help of corrected and feedback relative positioning data, the relative location of the host and wingman is achieved. The actual simulation results show that the relative position RMSE of the host, Wing Plane 1, and Wing Plane 2 in the X, Y, and Z dimensions are 1.345 m, 0.7388 m, 1.645 m, 2.167 m, 1.201 m, and 2.069 m, respectively. It is apparent that this scheme improves the relative navigation performance and robustness of the UAV group.
Design and characterization of a new high-count wide-range fission chamber based on GEM
Authors: Ye Yan-Xi , Zhao Xiu-Liang , Wang Xiao-Dong , Feng Song , Wei Qi-an , Tian Jin , He San-Jun
Published: May 2024

As one of the main detectors for monitoring neutron flux
rate in a nuclear reactor, the fission chamber (FC) suffers from
issues such as low sensitivity, limited counting rate dynamic range,
and system mode switching is cumbersome. This study utilizes the
advantages of gas electron multipliers (GEM), which are easy to
fabricate in large areas and have high counting rates, to design a
novel fission chamber. By conducting Monte Carlo simulations on
parameters such as the thickness of the 235U coating, the drift
distance, and the operating electric field strength, a wide-range
fission chamber design that combines high sensitivity and a counting
rate range based on GEM has been obtained. The simulation results
demonstrated that using a GEM detector to build a fission chamber
can significantly improve sensitivity and extend the counting rate
range. Subsequently we built a proof-of-concept GEM-based fission
chamber and tested it with a 55Fe low-energy X-ray source and
an Am-Be neutron source. The results showed that the
proof-of-concept detector had a good signal-to-noise ratio and
energy linearity, as well as clear discrimination between alpha
background and neutron pulse amplitudes.
Nonstationary thermodynamic and dynamic contributions to the interannual variability of winter sea ice growth in the Kara–Laptev Seas
Authors: Zhang Anjie , Yi Daling Li , Fan Ke
Published: May 2024

The Kara–Laptev Seas (KLS), known as the ‘Ice Factory of the Arctic’, witnesses rising instead of falling winter sea ice growth (WSIG) under the shrinkage of Arctic ice. However, knowledge of the large year-to-year variation is still unclear. Combining a seasonal ice concentration budget, a composite analysis, and a typical case study, we study both the interannual variability of WSIG in the KLS and the associated air-sea forcings during 1985–2021. Results quantitatively reveal that, during 1985–2021, thermodynamic melt in the melting season (April–August) contributed 80.3% to the interannual ice loss difference and promoted the subsequent WSIG by the recovery mechanism in the KLS. This consistent thermodynamic melt is caused by the strengthened summer Beaufort High, transporting heat and introducing a locally positive ice-albedo feedback. However, since 2010, the dynamic growth during the freezing season (October–February) has increasingly stimulated the WSIG. Typical cases in 2013 and 2017 indicate that the overlying anticyclonic atmospheric regime restricts the ice drift from the KLS and contributes to the dynamic growth of 41.6% of the WSIG difference, while the turbulent-heat-induced thermodynamic growth in winter is down to 58.4%. In short, we reveal an unstable relationship between the summer ice loss and the subsequent WSIG under the background of Arctic warming. Our study points out that the distinct dynamic ice growth driven by surface winds or ocean currents during the freezing season is likely to increase in the near future, with thinner and more mobile seasonal ice predominating in the Arctic.
Spinoza’s Theological-Political Treatise and the German Romantic Tradition
Authors: Forster Michael N
Published: May 2024

This chapter argues that the key figure in the channeling of Spinoza’s thought into German thought in the eighteenth century was the pre-Romantic philosopher Herder and that Herder’s earliest reception of it concerned not the Ethics, whose metaphysics he first embraced around 1773 but, rather, the Theological-Political Treatise, whose principles in philosophy of mind, hermeneutics, and political philosophy he already took over as early as 1768/9. The chapter explains Herder’s appropriation of ideas from the Theological-Political Treatise in each of these three areas. It then clarifies their continued influence via Herder on German Romanticism proper (Schleiermacher and Friedrich Schlegel).
Goethe and Spinoza on Faith, the State, and the Old Testament
Authors: Bollacher Martin
Published: May 2024

The relationship between Spinoza’s philosophy and Goethe’s own ideas, which Goethe himself refers to as “elective affinity,” is primarily guided by the Ethics and its identification of God and Nature. And yet, Goethe’s preoccupation with the Old Testament would be difficult to imagine without Spinoza’s historical-critical exegesis, his exploration of “libertas philosophandi,” or his distinction between national-religious authority and philosophy. Spinoza’s early influences can be inferred from the 1770s onward; his hermeneutic method had a fortifying effect on Goethe’s examination of the Book of Books, and the essay Israel in the Desert. Goethe’s direct knowledge of the TTP has been traced by H. E. G. Paulus to, at the latest, the 1802/3 edition of Spinoza’s Opera. But Goethe, whose engagement with Spinoza was widely influential, also differs from his “old lord and master” in his appreciation of the Bible as a record of prehistoric poetry.
Spinoza and the Growing Divide between Radical Enlightenment and Socialism in the German-Jewish Intellectual World of the 1830s and 1840s
Authors: Israel Jonathan
Published: May 2024

This chapter focuses on the divergent roles of early nineteenth-century intellectual revolutionaries Ludwig Börne, Heinrich Heine, and Moses Hess. It attempts to identify common ground between them and, more specifically, the reasons for the growing gulfs driving them apart despite their common rejection of the existing political, social, and religious status quo in Europe. Spinoza, both his philosophy and inspiring image, was to some extent a common bond, especially between Heine and Hess, and to a degree also between both of these and the young Karl Marx. At the same time, however, the growing incursion of early forms of socialism into their thinking came to operate as a factor driving their trajectories apart. While Heine’s revolutionary outlook is shown to be integral to the Radical Enlightenment tradition, the ideological positions of the others were definitely not.
David Friedrich Strauß and Spinoza
Authors: Beiser Frederick
Published: May 2024

This chapter outlines how “the father of unbelief” finally became, through a long struggle, the perfect Spinozist—more Spinozist in biblical interpretation than Spinoza was himself. David Friedrich Strauß may have explicitly engaged Spinoza only in lesser-known writings, and would initially have maintained Hegelian tendencies in tension with Spinoza, for instance finding philosophical truth in scripture by means of interpretation. However, Strauß would eventually abandon such Hegelianism and even come to criticize Spinoza for his inconsistency in elevating Christ, for his reading a naturalistic metaphysics into the Bible, and more. Insofar as he does so, he arguably adheres more closely to Spinoza’s hermeneutic principles, for instance proposing a focus on scripture itself in understanding scripture (solo scriptura), than Spinoza was able to.
Spinoza, Mendelssohn, and Hess on Zion
Authors: Harvey Warren Zev
Published: May 2024

Developing ideas of Maimonideans like Abulafia, Kaspi, and Polqar, Spinoza remarked in his Theological-Political Treatise that the re-establishment of the Jewish state would not be miraculous but natural. The ways of history are “changeable,” and nations rise, fall, and rise again. However, he continued, when opportunity presents itself to the Jews to regain their sovereignty, they will not be able to take advantage of it, since their religion has rendered their souls effeminate. When Mendelssohn was asked about a plan to re-establish the Jewish state, he replied that the Jewish nation does not have the strength for such a grand project. “Hundreds of years of oppression,” he wrote, “have drained our vigueur.” In Rome and Jerusalem, Moses Hess reinterpreted Spinoza’s remarks. “Spinoza,” he wrote, “held that the restoration of the Jewish state depends on the courage of the Jews.” This chapter aligns and elucidates these discussions.
“Let the Historian Be a Philosopher!”
Authors: Billet Shira
Published: May 2024

Spinoza developed a method of biblical interpretation that posited a strict division between Scripture’s history and philosophy’s history. Nineteenth-century philosophy’s more expansive sense of philosophy’s history created an opportunity to revisit Spinoza’s separation of philosophy from historical-philological sources such as the Bible. Hermann Cohen, with his unique background in philosophy as well as in classical and Hebrew philology, seized this opportunity in his extensive engagement with Spinoza in the final decade of his life. This chapter uncovers the methodological critique of Spinoza’s scriptural exegesis that is at the core of Cohen’s 1915 harshly critical monograph on Spinoza. To see the primarily philosophical-methodological aspect of Cohen’s work, it must especially be situated within a general methodological commitment to reading historical-philological sources philosophically, and vice versa, that he first developed in the 1870s and was central to Marburg neo-Kantianism.
Fractured Goodness
Authors: Shields Christopher
Published: May 2024

When Aristotle rejects Plato’s Form of the Good, he incurs a debt: given that he thinks that goodness is non-univocal—that there is no single, essence-specifying account of goodness covering all good things—he needs to provide an account of how the good things he wishes to compare and bring into ordinal rankings may be so ranked. For he also thinks that two things are commensurable under a single predicate F only if they are univocally F. We are thus left with two families of questions: (i) what, precisely, are Aristotle’s objections to the Form of the Good, and how successful are they? And (ii) on the assumption that they are successful, what is his alternative? Plato, it seems, whatever the final tenability of his theory may be, has an easy time with commensurability. He thinks that everything which qualifies as good does so because it participates in the Form of the Good, and that one good thing is better than another precisely to the degree that it realizes the Form of the Good by its participation in it. Given that according to Aristotle there simply is no Form of the Good, how and how well does he arrive at a defensible account of the commensurability of those good things he wishes to rank as better or worse than one another?
Augmentation of Nitric Oxide Deficient Hypertension by High Salt Diet Is Associated With Reduced TNF-α Receptor Type 1 Expression in the Kidneys
Authors: Majid Dewan S A , Prieto Minolfa C , Castillo Alexander , Chamberlain Cameron , Navar Luis Gabriel
Published: May 2024

BACKGROUND

High salt (HS) intake induces an augmented hypertensive response to nitric oxide (NO) inhibition, though it causes minimal changes in blood pressure (BP) in NO intact condition. The cause of such augmentation is not known. HS induces tumor necrosis factor-alpha (TNFα) production that causes natriuresis via activation of its receptor type 1 (TNFR1). We hypothesized that NO deficiency reduces renal TNFR1 activity, leading to enhanced sodium retention and hypertension.

METHODS

We examined the changes in renal TNFR1 protein expression (Immunohistochemistry analyses) after HS (4% NaCl) intake in wild-type mice (WT, C57BL6) treated with a NO synthase (NOS) inhibitor, nitro-l-arginine methyl ester (L-NAME; 0.05 mg/min/g; osmotic mini-pump), as well as in endothelial NOS knockout mice (eNOSKO) and compared the responses in WT mice with normal salt (NS; 0.3% NaCl) intake. BP was measured with tail-cuff plethysmography and 24-hour urine collections were made using metabolic cages.

RESULTS

HS alone did not alter mean BP in untreated mice (76 ± 3 to 77 ± 1 mm Hg) but induced an augmented response in L-NAME treated (106 ± 1 vs. 97 ± 2 mm Hg) and in eNOSKO (107 ± 2 vs. 89 ± 3 mm Hg) mice. The percentage area of TNFR1 expression in renal tissue was higher in WT + HS (4.1 + 0.5%) than in WT + NS mice (2.7 ± 0.6%). However, TNFR1 expression was significantly lower in L-NAME treated WT + NS (0.9 ± 0.1%) and in eNOSKO + NS (1.4 ± 0.2%) than in both WT + NS and WT + HS mice.

CONCLUSIONS

These data indicate that TNFR1 activity is downregulated in NO deficient conditions, which facilitates salt retention leading to augmented hypertension during HS intake.
Developing a design guideline of boronic acid derivatives to scavenge targeted sugars in the formose reaction products using DFT-based machine learning
Authors: Ishihara Nanako , Chikatani Genta , Nishijima Hiroaki , Tabata Hiro , Hase Yoko , Mukouyama Yoshiharu , Nakanishi Shuji , Mukaida Shiho
Published: May 2024

Formose reaction facilitates the synthesis of sugars from formaldehyde, yet the valuable sugars constitute only a small portion of the total products. This necessitates the need for a chemical scavenger capable of selectively capturing only valuable sugars. With over 600,000 potential combinations of boronic acid-based scavengers available, pursuing a deductive search approach is unfeasible. This study aims to derive guidelines for designing scavengers that readily bind with target sugars while avoiding nontarget ones via machine learning informed by density functional theory calculations.
Synthesis and chiroptical properties of cyclic anthraquinodimethane dimer using Au-templated method
Authors: Sugiyama Soichiro , Murotani Kazuharu , Ishiwari Fumitaka , Saeki Akinori , Kawai Hidetoshi , Suzuki Takanori , Tsuchido Yoshitaka , Ishigaki Yusuke
Published: May 2024

Cyclic anthraquinodimethane (AQD) dimer with a highly constrained structure was synthesized by using the Au-templated method. X-ray diffraction analysis and UV–Vis spectroscopy revealed that the AQD skeleton adopts a deeply folded structure and exhibits red-shifted absorptions in the dimer compared to those in noncyclized monomeric AQD. Due to the rigid and constrained structure, both enantiomers of the cyclic AQD dimer with planar chirality can be isolated and show strong circular dichroism signals. It is demonstrated that the Au-templated method is a valuable way to access a highly constrained cyclic structure with AQD skeletons.
Five-year outcomes of different techniques for minimally invasive mitral valve repair in Barlow’s disease
Authors: Pölzl Leo , Gollmann-Tepeköylü Can , Nägele Felix , Cetin Kardelen , Spilka Johannes , Holfeld Johannes , Oezpeker Ulvi C , Stastny Luka , Graber Michael , Hirsch Jakob , Engler Clemens , Dumfarth Julia , Ruttmann-Ulmer Elfriede , Hangler Herbert , Grimm Michael , Müller Ludwig , Höfer Daniel , Bonaros Nikolaos
Published: May 2024

OBJECTIVES

Barlow’s disease is a specific sub-form of mitral valve (MV) disease, characterized by diffuse excessive tissue and multi segment prolapse. The anterolateral mini-thoracotomy represents the standard access for MV regurgitation in many centres. It still remains unclear which surgical technique provides the best results. Therefore, the aim of this study was to compare operative safety and mid-term outcomes after (i) isolated annuloplasty, (ii) use of additional artificial chordae or (iii) leaflet resection in patients suffering from Barlow’s disease undergoing minimally invasive MV repair.

METHODS

A consecutive series of patients suffering from Barlow′s disease undergoing minimally invasive MV surgery between 2001 and 2020 were analysed (n = 246). Patients were grouped and analysed according to the used surgical technique. The primary outcome was a modified Mitral Valve Academic Research Consortium combined end-point of mortality, reoperation due to repair failure or reoccurrence of severe mitral regurgitation within 5 years. The secondary outcome included operative success and safety up to 30 days.

RESULTS

No significant difference was found between the 3 surgical techniques with regard to operative safety (P = 0.774). The primary outcome did not differ between groups (P = 0.244). Operative success was achieved in 93.5% and was lowest in the isolated annuloplasty group (77.1%). Conversion to MV replacement was increased in patients undergoing isolated annuloplasty (P < 0.001).

CONCLUSIONS

Isolated annuloplasty, use of additional artificial chordae and leaflet resection represent feasible techniques in Barlow patients undergoing minimally invasive MV surgery with comparable 5-year results. In view of the increased conversion rate in the annuloplasty group, the pathology should not be oversimplified.
Increased hepatic glucagon sensitivity in totally pancreatectomised patients
Authors: Rix Iben , Lund Asger B , Garvey Lars F , Hansen Carsten P , Chabanova Elizaveta , Hartmann Bolette , Holst Jens J , Vilsbøll Tina , Van Hall Gerrit , Knop Filip K
Published: May 2024

Objective

The metabolic phenotype of totally pancreatectomised patients includes hyperaminoacidaemia and predisposition to hypoglycaemia and hepatic lipid accumulation. We aimed to investigate whether the loss of pancreatic glucagon may be responsible for these changes.

Methods

Nine middle-aged, normal-weight totally pancreatectomised patients, nine patients with type 1 diabetes (C-peptide negative), and nine matched controls underwent two separate experimental days, each involving a 150-min intravenous infusion of glucagon (4 ng/kg/min) or placebo (saline) under fasting conditions while any basal insulin treatment was continued.

Results

Glucagon infusion increased plasma glucagon to similar high physiological levels in all groups. The infusion increased hepatic glucose production and decreased plasma concentration of most amino acids in all groups, with more pronounced effects in the totally pancreatectomised patients compared with the other groups. Glucagon infusion diminished fatty acid re-esterification and tended to decrease plasma concentrations of fatty acids in the totally pancreatectomised patients but not in the type 1 diabetes patients.

Conclusion

Totally pancreatectomised patients were characterised by increased sensitivity to exogenous glucagon at the level of hepatic glucose, amino acid, and lipid metabolism, suggesting that the metabolic disturbances characterising these patients may be rooted in perturbed hepatic processes normally controlled by pancreatic glucagon.
Neurexin drives Caenorhabditis elegans avoidance behavior independently of its post-synaptic binding partner neuroligin
Authors: Muirhead Caroline S , Reddy Kirthi C , Guerra Sophia , Rieger Michael , Hart Michael P , Srinivasan Jagan , Chalasani Sreekanth H
Published: May 2024

Neurexins and their canonical binding partners, neuroligins, are localized to neuronal pre-, and post-synapses, respectively, but less is known about their role in driving behaviors. Here, we use the nematode C. elegans to show that neurexin, but not neuroligin, is required for avoiding specific chemorepellents. We find that adults with knockouts of the entire neurexin locus exhibit a strong avoidance deficit in response to glycerol and a weaker defect in response to copper. Notably, the C. elegans neurexin (nrx-1) locus, like its mammalian homologs, encodes multiple isoforms, α and γ. Using isoform-specific mutations, we find that the γ isoform is selectively required for glycerol avoidance. Next, we used transgenic rescue experiments to show that this isoform functions at least partially in the nervous system. We also confirm that the transgenes are expressed in the neurons and observe protein accumulation in neurites. Furthermore, we tested whether these mutants affect the behavioral responses of juveniles. We find that juveniles (4th larval stages) of mutants knocking out the entire locus or the α-isoforms, but not γ-isoform, are defective in avoiding glycerol. These results suggest that the different neurexin isoforms affect chemosensory avoidance behavior in juveniles and adults, providing a general principle of how isoforms of this conserved gene affect behavior across species.
The molecular machinery for maturation of primary mtDNA transcripts
Authors: Vučković Ana , Freyer Christoph , Wredenberg Anna , Hillen Hauke S
Published: May 2024

Human mitochondria harbour a circular, polyploid genome (mtDNA) encoding 11 messenger RNAs (mRNAs), two ribosomal RNAs (rRNAs) and 22 transfer RNAs (tRNAs). Mitochondrial transcription produces long, polycistronic transcripts that span almost the entire length of the genome, and hence contain all three types of RNAs. The primary transcripts then undergo a number of processing and maturation steps, which constitute key regulatory points of mitochondrial gene expression. The first step of mitochondrial RNA processing consists of the separation of primary transcripts into individual, functional RNA molecules and can occur by two distinct pathways. Both are carried out by dedicated molecular machineries that substantially differ from RNA processing enzymes found elsewhere. As a result, the underlying molecular mechanisms remain poorly understood. Over the last years, genetic, biochemical and structural studies have identified key players involved in both RNA processing pathways and provided the first insights into the underlying mechanisms. Here, we review our current understanding of RNA processing in mammalian mitochondria and provide an outlook on open questions in the field.