物理最新文献

{"title":"Correction: Varying Newton’s constant: a cure for gravitational maladies?","authors":"Saurya Das, Sourav Sur","doi":"10.1140/epjp/s13360-024-05927-0","DOIUrl":"10.1140/epjp/s13360-024-05927-0","url":null,"abstract":"","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"139 12","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stability of compact stars in a uniform density background cloud","authors":"Ksh. Newton Singh,&nbsp;S. K. Maurya,&nbsp;A. Errehymy,&nbsp;O. Donmez,&nbsp;K. Myrzakulov,&nbsp;T. T. Smitha","doi":"10.1140/epjc/s10052-024-13661-1","DOIUrl":"10.1140/epjc/s10052-024-13661-1","url":null,"abstract":"<div><p>We are discussing a scenario where a compact star (neutron star, NS) is embedded in a thin, uniform density background cloud (a remnant cloud after a supernova or a cloud generated from the late stages of a star e.g., a planetary nebula or asymptotic red giant phases) and its effect on the stability of the compact star. Due to the thin background cloud, the spacetime geometry is minimally deformed allowing us to employ the technique of minimal geometric decoupling (MGD). Assuming a uniform background cloud density simplifies the problem, and through the MGD method, one can take <span>(Theta ^t_t = Theta &gt; 0)</span>, where <span>(Theta )</span> is the density of the cloud. The background cloud interacts with the compact star through a coupling strength <span>(alpha )</span>. By varying <span>(alpha )</span>, one can tune the cloud density to analyze the stability of the embedded compact star. We found that for <span>(alpha &lt; 3 times 10^{-5})</span>, all the thermodynamic quantities are well-behaved, indicating a stable configuration. Once the coupling parameter exceeds <span>(3 times 10^{-5})</span>, the adiabatic index drops below <span>(Gamma _{text {max}}')</span>, triggering a gravitational collapse. Beyond this limit of <span>(alpha )</span>, the pressure and speed of sound also become non-physical. At the end, we have used the <span>(M-R)</span> curve generated from the solution to determine the radii of a few compact stars, namely PSR J1614-2230, PSR J0952-0607, GW190814, and GW200210. Furthermore, we have discussed the possibility of the secondary component of GW200210 i.e. the less massive compact object with an upper mass of <span>(3.3M_odot )</span>, which may be a stellar black hole with a Schwarzschild radius <span>(R_{text {BH}} = 9.746)</span> km. However, if the mass is <span>(2.83M_odot )</span> as observed, then its predicted minimum radius is 10.74 km, corresponding to <span>(alpha = 0)</span>. This radius is far beyond <span>(R_{text {BH}} = 8.357)</span> km and therefore is most probably a massive NS in the mass gap.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"84 12","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-024-13661-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CRISPR/Cas System Photocontrolled at the Guide RNA Level","authors":"L. V. Sakovina,&nbsp;E. S. Gorlenko,&nbsp;D. S. Novopashina","doi":"10.1134/S000635092470043X","DOIUrl":"10.1134/S000635092470043X","url":null,"abstract":"<div><p>Improving the efficiency and precision of gene editing systems is of utmost importance for modern molecular biology and genetic engineering. Of particular interest is the design of controlled CRISPR/Cas9 systems, the activity of which could be regulated using various physicochemical stimuli, such as light irradiation, pH change, temperature, change of molecule concentration, and others. A promising direction in this area is the development of approaches to control activity at the level of guide RNA through photosensitive modifications to the structure and sequence of guide RNA, and additional oligonucleotides. This review focuses on the analysis of publications on design of photosensitive guide RNAs and their applications in gene editing systems using CRISPR.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"69 3","pages":"349 - 358"},"PeriodicalIF":4.033,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the role of soft and non-perturbative gluons in collinear parton densities and parton shower event generators","authors":"M. Mendizabal,&nbsp;F. Guzman,&nbsp;H. Jung,&nbsp;S. Taheri Monfared","doi":"10.1140/epjc/s10052-024-13657-x","DOIUrl":"10.1140/epjc/s10052-024-13657-x","url":null,"abstract":"<div><p>The Parton Branching method offers a Monte Carlo solution to the DGLAP evolution equations by incorporating Sudakov form factors. In this approach, the Sudakov form factor can be divided into perturbative and non-perturbative components, with the non-perturbative part being analytically calculable under specific conditions. We first examine forward evolution and demonstrate that including soft and non-perturbative gluons (through the non-perturbative Sudakov form factor) is essential for the proper cancellation of divergent terms in parton density evolution. This non-perturbative component is also important for Transverse Momentum Dependent (TMD) parton distributions, and within the Parton Branching framework, it is constrained by fits to inclusive collinear parton densities. Additionally, we explore the impact of this non-perturbative Sudakov form factor on backward parton evolution and its effects on parton and hadron spectra originating from initial state showers. Our results show that soft and non-perturbative gluons significantly influence inclusive distributions, such as Drell–Yan transverse momentum spectra. However, we found that soft and non-perturbative gluons have a minimal impact on final state hadron spectra and jets.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"84 12","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-024-13657-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Study of the Effects of Physico-Chemical Factors on the Frequency of Plasmid Transduction by Bacteriophage RB49","authors":"A. N. Nikulina,&nbsp;N. A. Nikulin,&nbsp;A. A. Zimin","doi":"10.1134/S0006350924700532","DOIUrl":"10.1134/S0006350924700532","url":null,"abstract":"<div><p>T4-related bacteriophage RB49 is capable of general plasmid transduction with a relatively high frequency. Due to this mechanism, bacteria can acquire the ability to adapt to changing environmental conditions and explore new ecological niches. The effects of pH, temperature, and irradiation with long-wavelength ultraviolet light (λ = 366 nm) on the characteristics of the phage RB49 preparation containing transducing particles with pTurboGFP-B plasmid DNA and virulent particles with their own DNA were studied. Data on changes in the titer of virulent particles and the frequency of transduction of the pTurboGFP-B plasmid by the RB49 phage were obtained. After exposure to UV radiation for 2 h, the frequency of transduction of the pTurboGFP-B plasmid by the RB49 phage increased by ~3 times. After storing the preparation in ice for 40 min, a several-fold increase in the transduction frequency was observed. Based on the experimental data we obtained, it was assumed that the transducing particles of the RB49 phage may be more resistant to long-wavelength UV radiation and temperatures close to 0°C than virulent ones and provide the transduction process more efficiently than under normal conditions. Similar processes can occur in well-lit reservoirs, including cold ones, in which phages related to RB49 may occur. This indicates the possibility of more intensive horizontal gene transfer in aquatic ecotopes than previously assumed.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"69 3","pages":"459 - 469"},"PeriodicalIF":4.033,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Effect of a Combination of Local Moderate Heating and Illumination on the Indicators of Water Metabolism of Intact Parts of Wheat Measured by Thermal Imaging","authors":"A. Yu. Popova,&nbsp;Yu. A. Zolin,&nbsp;V. S. Sukhov,&nbsp;E. M. Sukhova,&nbsp;L. M. Yudina","doi":"10.1134/S0006350924700593","DOIUrl":"10.1134/S0006350924700593","url":null,"abstract":"<div><p>Natural stress factors can lead to crop loss; when they act locally, stress signals spread, modifying the physiological state and increasing plant resistance. The purpose of this work was to study the effect of a combination of local factors on water metabolism under watering and drought. Wheat was grown in a greenhouse cabinet; drought was created by stopping watering. To assess the water metabolism, a modified index of stomatal conductivity measured by a thermal imager, the water conductivity of the leaf, and the relative water content in the leaves were used. It was found that the conductivity index decreased during drought and had a strong correlation with the hydration status of the plant (<i>R</i> &gt; 0.7, <i>p</i> &lt; 0.05). Under watering, the combined effect led to a decrease in the conductivity index compared to the condition without stimulation; the response decreased with increasing the distance from the stimulation zone. Soil drought reduced the amplitude of changes in the conductivity index. The local action of heating alone and illumination alone did not cause conductivity index changes. The results showed that the local effect of the combination of heating and illumination caused stress signals that reduced the water metabolism of wheat. Potentially, such signals might be of an electrical nature; however, the absence of changes in the conductivity index under drought and the effect of heating alone did not confirm this hypothesis.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"69 3","pages":"522 - 532"},"PeriodicalIF":4.033,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Energy conditions in Gauss–Bonnet gravity","authors":"Francesco Bajardi","doi":"10.1140/epjc/s10052-024-13673-x","DOIUrl":"10.1140/epjc/s10052-024-13673-x","url":null,"abstract":"<div><p>We study the Energy Conditions in modified <span>(f(mathcal {G}))</span> gravity, with <span>(mathcal {G})</span> being the topological Gauss–Bonnet term. Then we use the cosmographic parameters to constrain the functional form of the gravitational action and investigate the possibility to have standard inflation in the early time. Specifically, we select models containing symmetries within the modified <span>(f(mathcal {G}))</span> theory and obtain conditions for which (i) the energy conditions can be violated and (ii) the magnitude of the slow-roll parameters is small, thus suggesting that under given limits the analyzed theory can potentially trace the cosmic history both at early and at the late times.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"84 12","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-024-13673-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Effect of Genistein on the Structure of Nucleosomes and the Formation of Complexes with PARP1","authors":"T. V. Andreeva,&nbsp;A. V. Efremenko,&nbsp;A. V. Feofanov,&nbsp;A. V. Lyubitelev,&nbsp;A. N. Korovina,&nbsp;V. M. Studitsky,&nbsp;N. V. Maluchenko","doi":"10.1134/S0006350924700441","DOIUrl":"10.1134/S0006350924700441","url":null,"abstract":"<div><p>A plant-derived polyphenol, genistein, has a high level of biological activity, which stimulates the study of its applicability for the prevention and treatment of tumor, cardiovascular and neurodegenerative diseases. Taking into account the ability of genistein to bind to DNA the interaction of genistein with nucleosomes and nucleosome complexes with <b>poly(ADP-ribose</b>) polymerase 1 (PARP1) has been studied in this work. It was found that genistein did not affect the structure of nucleosomal DNA in a wide range of concentrations, while at high concentrations it caused a change in the structure of linker DNA, bringing the DNA helices closer together. In chromatosomes, genistein did not cause dissociation of the linker histone and conformation changes in the linker DNA region. At high concentrations, genistein hindered the formation of nucleosome complexes with PARP1.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"69 3","pages":"359 - 369"},"PeriodicalIF":4.033,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on laser quenching of aircraft gears with rectangular beam based on multi-field coupling mechanism","authors":"Jiangtao Zhao,&nbsp;Chang Li,&nbsp;Hao Zhan,&nbsp;Menghui Yu,&nbsp;Xing Han","doi":"10.1007/s00339-024-08174-3","DOIUrl":"10.1007/s00339-024-08174-3","url":null,"abstract":"<div><p>The aircraft engine plays an important role in the aviation field, and the gear is the key part of the aircraft engine. During the service, the contact fatigue of the gears surface aggravates the gears surface wear and leads to the initiation of micro-cracks. Laser quenching surface heat treatment technology is one of the effective ways to strengthen the surface of aircraft gear. Due to the solid-state phase transition effect of laser quenching, the residual stress can be effectively controlled, the formation of micro-cracks on the gears surface can be reduced, and the uniform distribution of the quenching layer on the gears surface is realized. To enhance laser quenching efficiency and ensure precise process control, a rectangular laser heat source model was established. This model was based on the characteristics of actual laser processing heat sources. A numerical model coupling temperature, stress, and phase transition was developed for 12Cr2Ni4A aircraft gear double lap laser quenching, revealing the process’s instantaneous evolution. The numerical simulation results show the temperature characteristics of laser quenching rapid heating and cooling, and residual stress concentration distribution phenomenon appears in the secondary tempering zone. The phase transformation results after quenching reveal the presence of a large amount of martensite in the quenching layer. Finally, the effectiveness of the numerical simulation was verified by the laser quenching experiment of the aircraft gear. The research on laser quenching of aircraft gears is crucial for improving their surface hardness, wear resistance, and extending their service life.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Periapsis precession in general stationary and axisymmetric spacetimes","authors":"Jinhong He,&nbsp;Shaofei Xu,&nbsp;Junji Jia","doi":"10.1140/epjc/s10052-024-13680-y","DOIUrl":"10.1140/epjc/s10052-024-13680-y","url":null,"abstract":"<div><p>This work studies the periapsis shift in the equatorial plane of arbitrary stationary and axisymmetric spacetimes. Two perturbative methods are systematically developed. The first works for small eccentricity but very general orbit size and the second, which is post-Newtonian and includes two variants, is more accurate for orbits of large size but allows general eccentricity. Results from these methods are shown to be equivalent under small eccentricity and large size limits. The periapsis shift of Kerr–Newman, Kerr–Sen and Kerr–Taub-NUT spacetimes is computed to high orders. The electric charge and NUT charge are shown to contribute to the leading order but with opposite signs. The frame-dragging term and high-order effect of spacetime spin are given. The electric and NUT charges of the Earth, Sun and Sgr A* are constrained using the Mercury, satellite and S2 precession data. Periapsis shifts of other spacetimes are obtained too.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"84 12","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-024-13680-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}