Research on bionic composite guidance law considering field of view angle

Due to the use of strapdown seeker in small missiles, a small field of view angle is required to ensure effective tracking and strike of the target during the final interception. Based on the tracking strategy of dragonfly chasing targets, a composite guidance law is studied. In the initial guidance section, the parallax angle is controlled by the sliding mode control law to adjust the missile to the tail following attitude. The final guidance section used the motion camouflage guidance law with the focus at infinity for target tracking,and between the initial guidance and the final guidance. The second-order smooth interface law is used for the transition. The simulation results show that compared with the traditional proportional guidance law, the required overload of the missile in the final guidance is small,and the target is closer to the center of the field of view, which can reduce the missile in the final guidance. The overload and the field of view of the seeker can be used to effectively improve the attack accuracy

Global trends in COVID-19 Alzheimer's related research: a bibliometric analysis

BackgroundThe COVID-19 pandemic has significantly impacted public health, putting people with Alzheimer's disease at significant risk. This study used bibliometric analysis method to conduct in-depth research on the relationship between COVID-19 and Alzheimer's disease, as well as to predict its development trends.MethodsThe Web of Science Core Collection was searched for relevant literature on Alzheimer's and Coronavirus-19 during 2019–2023. We used a search query string in our advanced search. Using Microsoft Excel 2021 and VOSviewer software, a statistical analysis of primary high-yield authors, research institutions, countries, and journals was performed. Knowledge networks, collaboration maps, hotspots, and regional trends were analyzed using VOSviewer and CiteSpace.ResultsDuring 2020–2023, 866 academic studies were published in international journals. United States, Italy, and the United Kingdom rank top three in the survey; in terms of productivity, the top three schools were Harvard Medical School, the University of Padua, and the University of Oxford; Bonanni, Laura, from Gabriele d'Annunzio University (Italy), Tedeschi, Gioacchino from the University of Campania Luigi Vanvitelli (Italy), Vanacore, Nicola from Natl Ctr Dis Prevent and Health Promot (Italy), Reddy, P. Hemachandra from Texas Tech University (USA), and El Haj, Mohamad from University of Nantes (France) were the authors who published the most articles; The Journal of Alzheimer's Disease is the journals with the most published articles; “COVID-19,” “Alzheimer's disease,” “neurodegenerative diseases,” “cognitive impairment,” “neuroinflammation,” “quality of life,” and “neurological complications” have been the focus of attention in the last 3 years.ConclusionThe disease caused by the COVID-19 virus infection related to Alzheimer's disease has attracted significant attention worldwide. The major hot topics in 2020 were: “Alzheimer' disease,” COVID-19,” risk factors,” care,” and “Parkinson's disease.” During the 2 years 2021 and 2022, researchers were also interested in “neurodegenerative diseases,” “cognitive impairment,” and “quality of life,” which require further investigation

Ethyl Pyruvate Attenuates CaCl2-Induced Tubular Epithelial Cell Injury by Inhibiting Autophagy and Inflammatory Responses

Background/Aims: Nephrolithiasis is one of the most prevalent diseases of the urinary system. Approximately 80% of human kidney stones are composed of calcium oxalate (CaOx), and hypercalciuria is one of the most common metabolic disorders. Emerging evidence indicates that autophagy and inflammatory responses are related to the formation of CaOx nephrolithiasis. However, the roles of autophagy and inflammation in patients with hypercalciuria remain unclear. Ethyl pyruvate (EP) displays protective effects in experimental models of many illnesses. In this study, we investigated the protective effects of EP in vitro through its inhibition of autophagy and inflammatory responses after CaCl2-induced tubular epithelial cell injury. Methods: First, we cultured human tubular epithelial (HK-2) cells in the presence of various concentrations of CaCl2 (0, 0.1, 0.25, 0.5, 1.0, 1.5, and 2.0 mg/ml) for 12 h and EP (0, 1.0, 2.5, 5.0, and 10.0 mM) for 2 h to select the optimum concentration using the Cell Counting Kit-8 assay and lactate dehydrogenase (LDH) assay. Cells in culture were stimulated with CaCl2 (1.0 mg/ml, 12 h) with or without EP pretreatment (2.5 mM, 2 h). After the exposure, we detected the expression of inflammation-related proteins using an enzyme-linked immunosorbent assay and Western blot analysis. Finally, the levels of autophagy-related proteins were determined through Western blot analysis, and the number of GFP-LC3 dots and autophagic vacuoles was detected under confocal microscopy. Results: With the use of the Cell Counting Kit-8 assay and the LDH assay, we identified the optimum concentration for CaCl2 (1.0 mg/ml) treatment and EP pretreatment (2.5 mM). Our research indicated that CaCl2 can induce autophagy and inflammatory responses in HK-2 cells. Furthermore, treatment with EP prior to CaCl2 stimulation attenuated HK-2 cell injury by inhibiting autophagy and inflammation. Conclusion: Our results provide evidence that EP attenuates CaCl2-induced injury of HK-2 cells by downregulating the expression of inflammation and autophagy proteins that may be associated with the inhibition of the high-mobility group box-1 (HMGB1)/toll-like receptor 4 (TLR4)/NF-κB pathway and the competitive interaction with Beclin-1 of HMGB1

EVALUATING A SOLID-PHASE EXTRACTION METHOD WITH NOVEL POROUS CYCLODEXTRIN POLYMERS

Organic micropollutants (MPs) occur ubiquitously in the aquatic environment at trace concentrations, which presents great challenges for environmental monitoring. Solid-phase extraction (SPE) is a widely-used sample preparation procedure that concentrates MPs in environmentally derived water samples. SPE relies on columns packed with an adsorbent material that captures MPs from water samples. Loaded SPE adsorbents can then be eluted with organic solvents to release the captured MPs. The conventional adsorbent used for SPE is a hydrophilic-lipophilic balanced material available from a variety of commercial vendors, often referred to as HLB. These HLB adsorbents feature stability at extreme pHs and high retention of polar and apolar organic MPs. The primary disadvantage of HLB adsorbent materials is price, which often makes sample preparation the most expensive step in an environmental monitoring workflow. In this research, novel porous β-cyclodextrin polymers (P-CDP) were evaluated as an alternative SPE adsorbent. Cyclodextrins are sustainably produced macrocycles of glucose, featuring a hydrophobic interior cavity that forms host-guest complexes with thousands of organic molecules. P-CDP is a polymer of cyclodextrin and is synthesized in one-step, making it relatively inexpensive to produce. The objective of this research was to develop an SPE procedure using P-CDP and compare its performance to a conventional SPE procedure using HLB. A set of 189 MPs were included in the study and the P-CDP method was optimized to maximize efficiency in MP capture and MP release. The optimized P-CDP method exhibits moderate absolute recovery (≥60%) for 135 (75%) MPs and high absolute recovery (≥80%) for 121 (67%) MPs. The conventional HLB method exhibits moderate absolute recovery for 130 (72%) MPs and high absolute recovery for 109 (61%) MPs. The results of this research demonstrate that P-CDP could be used as a cost-effective SPE adsorbent

A Small Hybrid Power System of Photovoltaic Cell and Sodium Borohydride Hydrolysis-Based Fuel Cell

Although the hybrid power system that combines a photovoltaic cell and a lithium-ion battery is increasingly mature and practical, long-lifetime auxiliary power will be still needed in severe weather conditions. A small-volume hydrogen–oxygen fuel cell system based on the hydrolysis of NaBH4 is designed. The fuel cell system contains a tiny hydrogen generator, a hydrogen cleaner, and a small fuel cell stack consisting of three units in series. The relationship between the amount of catalyst and output performance is discussed. The long-time discharging results indicate that the fuel cell system has high power capacity. The compact design allows the fuel cell system to integrate the structure with a photovoltaic cell and lithium-ion cell and forms a hybrid power system with a small package. The power management circuit for these power sources without logic devices is designed and tested. The control strategy selects the photovoltaic–battery subsystem as the primary power source, and the fuel cell subsystem works as the backup power source to handle the circumstance when the energy stored in the battery is exhausted. The test results show that the power management system could switch the power supply automatically and timely under various emergency conditions, and the output voltage remains stable all the time

Effects of Self-Assembled Monolayers with Different Chemical Groups on Ovarian Cancer Cell Line Behavior In Vitro

In addition to serving as a physical support, the extracellular matrix (ECM) actively influences cell behavior. However, the definitive effects of different chemical structures present in the ECM on cell behavior remain obscure. The current study aimed to investigate the effects of different chemical structures present in the ECM on cellular physiology using the ovarian cancer cell line SKOV-3 as a model. Self-assembled monolayers (SAMs) with different chemical modifications, including methyl (-CH3), hydroxyl (-OH), amino (-NH2), carboxyl (-COOH), and mercapto (-SH) groups, were used as microenvironmental models to explore the effects of different structures on SKOV-3 cells. The cell morphology, cell adhesion, cytotoxicity, and functional alterations in cancer cells cultured on different SAMs were analyzed. The results showed that SKOV-3 cells cultured on -NH2 surfaces exhibited the largest contact area, whereas those on -CH3 surfaces exhibited the smallest contact area and mostly rounded morphologies. Additionally, -NH2 and -COOH promoted cell proliferation and adhesion, whereas CH3 inhibited adhesion, leading to G1 arrest during the cell cycle and resulting in cell apoptosis. This study may provide useful information for reconstruction of the ECM and for controlling cell behavior in related areas of study

Structure-oriented substrate specificity engineering of aldehyde-deformylating oxygenase towards aldehydes carbon chain length

Background: Aldehyde-deformylating oxygenase (ADO) is an important enzyme involved in the biosynthetic pathway of fatty alk(a/e)nes in cyanobacteria. However, ADO exhibits quite low chain-length specificity with respect to the substrates ranging from C-4 to C-18 aldehydes, which is not suitable for producing fuels with different properties or different chain lengths.</p

Multiagent Gumbel MuZero: Efficient Planning in Combinatorial Action Spaces

AlphaZero and MuZero have achieved state-of-the-art (SOTA) performance in a wide range of domains, including board games and robotics, with discrete and continuous action spaces. However, to obtain an improved policy, they often require an excessively large number of simulations, especially for domains with large action spaces. As the simulation budget decreases, their performance drops significantly. In addition, many important real-world applications have combinatorial (or exponential) action spaces, making it infeasible to search directly over all possible actions. In this paper, we extend AlphaZero and MuZero to learn and plan in more complex multiagent (MA) Markov decision processes, where the action spaces increase exponentially with the number of agents. Our new algorithms, MA Gumbel AlphaZero and MA Gumbel MuZero, respectively without and with model learning, achieve superior performance on cooperative multiagent control problems, while reducing the number of environmental interactions by up to an order of magnitude compared to model-free approaches. In particular, we significantly improve prior performance when planning with much fewer simulation budgets. The code and appendix are available at https://github.com/tjuHaoXiaotian/MA-MuZero

Genetic Determinants of Symptoms on Viral DNA Satellites ▿

Begomovirus-DNA-β disease complexes induce different symptom phenotypes in their hosts. To investigate the genetic determinants of the phenotypic differences, Nicotiana spp. and tomato plants were inoculated with infectious clones of Tobacco curly shoot virus (TbCSV)/TbCSV DNA-β (TbCSB) and Tomato yellow leaf curl China virus (TYLCCNV)/TYLCCNV DNA-β (TYLCCNB) pseudorecombinants and showed that TYLCCNB induced characteristic vein-thickening and enation symptoms, while TbCSB only slightly exacerbated the leaf-curling symptoms, regardless of the helper virus being used. The roles of DNA-β-encoded βC1 and a 430-nucleotide fragment containing the A-rich region and the putative βC1 promoter region of the βC1 gene (referred to as AP) in symptom development were further investigated by constructing hybrid satellites in which the βC1 coding region or AP was exchanged between the two satellite molecules. A TYLCCNB hybrid with TbCSB βC1 lost the ability to elicit the vein-thickening and enation phenotypes. TbCSB hybrids containing the TYLCCNB βC1 or AP fragment failed to induce the characteristic vein thickening and enations. A TYLCCNB hybrid having the TbCSB AP fragment produced the enations, but the number of enations was less and their sizes were reduced. Differently from the phloem-specific pattern of the TYLCCNB promoter, a full-length fragment upstream of the TbCSB βC1 gene confers a constitutive β-glucuronidase expression pattern in transgenic tobacco plants. The above results indicate that the DNA-β-encoded βC1 protein is the symptom determinant, but the promoter of the βC1 gene has influence on symptom production