物理最新文献

{"title":"Acclimation of Primary Photosynthetic Reactions in the Cells of Chlamydomonas reinhardtii to Cadmium: Analysis of Cell Population Heterogeneity","authors":"A. A. Volgusheva,&nbsp;I. V. Konyukhov,&nbsp;T. K. Antal","doi":"10.1134/S0006350924700489","DOIUrl":"10.1134/S0006350924700489","url":null,"abstract":"<div><p>The mechanisms of acclimation of primary photosynthetic reactions in the green microalgae <i>Chlamydomonas reinhardtii</i> to the toxic action of cadmium were investigated by analyzing the dynamics of the distribution of key photosynthetic parameters in the cell population. A synchronous culture of microalgae was incubated for 96 h in the presence of 25 μM Cd, and OJIP-transient curves of individual cells were recorded at different stages of incubation with the toxicant using an original microfluorometer. The analysis of OJIP-transient curves made it possible to determine distributions of key JIP-test parameters: <i>F</i>_V/<i>F</i>_M, <i>ET</i>_O/<i>ABS</i>, <i>RC</i>/<i>ABS</i>, which represent photochemical activity of PS II, electron transport in PS II, and light absorption per active reaction center in PS II, respectively. Acclimation of primary photosynthetic reactions in microalgae to cadmium was accompanied by the appearance of two dominating cell fractions, which demonstrated the stable values of photosynthetic parameters when energy imbalance occurred due to the presence of the toxicant. The cells related to the first fraction retained moderate PS II activity by the effect of reduced PS II antenna size, while the cells of the second fraction showed low photochemical activity of PS II keeping antenna size similar to that of the control cells.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"69 3","pages":"401 - 407"},"PeriodicalIF":4.033,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859547","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":"Response surface methodology for the optimisation of heat transfer rate for concatenated non-Newtonian fluid flow over a curved stretching sheet","authors":"Pradeep Kumar,&nbsp;F Almeida,&nbsp;B Nagaraja,&nbsp;A R Ajaykumar","doi":"10.1007/s12043-024-02838-8","DOIUrl":"10.1007/s12043-024-02838-8","url":null,"abstract":"<div><p>The current article unveils the repercussions obtained from analysing the Casson–Williamson nanofluid flow across a curved stretched surface using the Darcy–Forchheimer model. The modelling is contemplated with homogeneous–heterogeneous chemical reactions. The impact of nonlinear thermal radiation, exponential heat source and magnetic field is considered. Further, response surface methodology is a statistical technique used to understand the association of parametric factors under consideration on the response which is the Nusselt number in the present context. The prime aim of this modelling is to give optimal conditions for producing the highest heat transfer rate to build an efficient model with the aid of sensitivity analysis. In addition, entropy propagated in the media is provided to enhance the importance of this investigation. Runge–Kutta–Fehlberg 4–5th order technique has been used to obtain the numerical output. The analysis reveals that the first-order slip component has a negative effect on velocity distribution, whereas the second-order slip factor has the opposite effect. The Nusselt number decreases as the unsteadiness parameter reaches its maximum value and when the sheet is susceptible to intense radiation. Graphical representations of streamlines and isotherms are provided to illustrate the flow and heat distribution. The sensitivity analysis emphasises that the Brownian motion parameter has positive sensitivity, whereas thermophoresis and an exponential heat source have negative sensitivity on the Nusselt number.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"99 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"The Effect of the Component Composition of Saliva on the Orientation of Two-Enzyme Bioluminescent Analysis Depending on the Type of Physical Load","authors":"V. V. Malysheva,&nbsp;L. V. Stepanova,&nbsp;A. M. Vyshedko,&nbsp;L. V. Bel’skaya,&nbsp;E. A. Sarf,&nbsp;Z. Khalzhanova,&nbsp;O. A. Kolenchukova,&nbsp;V. A. Kratasyuk","doi":"10.1134/S0006350924700635","DOIUrl":"10.1134/S0006350924700635","url":null,"abstract":"<div><p><b>Abstract</b>—The saliva of athletes with anaerobic (track and field athletes) and aerobic (swimmers) physical loads was studied. Saliva was collected before (in a state of physical rest) and after training. It was found that physical load significantly increased the concentration of total protein in saliva and the activity of hydrogen ions (pH) in the saliva. Catalase activity in saliva was significantly increased only after aerobic physical load, as opposed to anaerobic load. The bioluminescent saliva index was significantly increased for athletes engaged in aerobic physical load compared to that for an anaerobic load. Saliva biomarkers such as the concentration of lactate and total protein, catalase activity, concentration of calcium, potassium, and magnesium ions, as well as the content of group IV amides, had a significant effect on the enhancement of light emission in a bioluminescent two-enzyme reaction. The content of group IV amides and a complex of oligosaccharides, polysaccharides, phosphatase, and phospholipids in the saliva of athletes engaged in anaerobic physical load could more strongly inhibit bioluminescent glow than the concentration of triene conjugates and the content of group II amides in the saliva of athletes engaged in aerobic physical load. Thus, significant biomarkers of the physiological state of the body have been identified in the saliva of athletes engaged in aerobic or anaerobic physical loads, which were able to affect the integral response of a bioluminescent enzymatic biotest. A change in the integral bioluminescent saliva index, depending on the type of physical load for an athlete, can be used in sports medicine to prevent physical overloads.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"69 3","pages":"566 - 574"},"PeriodicalIF":4.033,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859642","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":"A novel approach for the temperature prediction of ring laser gyroscope using teamwork optimization enabled bias-compensated long short-term memory","authors":"T. Ezhilarasi,&nbsp;P. Sasikumar,&nbsp;C. S. Narayanamurthy","doi":"10.1140/epjp/s13360-024-05916-3","DOIUrl":"10.1140/epjp/s13360-024-05916-3","url":null,"abstract":"<div><p>Ring laser gyro (RLG) has turned out to be the predominant rotation rate sensor used in high-precision strap-down inertial navigation systems (SINS), extensively employed in the aerospace field nowadays. However, in actual space environments, temperature variation within the device leads to an uneven RLG bias error which results in performance degradation of SINS. To resolve this issue, diverse compensation methods have been performed carefully with comprehensive analysis to enhance environmental adaptability. Moreover, a bias of RLG changes with temperature in a nonlinear manner, which is a significant restraining factor to enhance the accuracy of RLG. In this paper, a novel method is developed using a deep learning model to predict the temperature model for the sensor. Initially, sensor data are pre-processed by min–max normalization and then, it is subjected to feature selection using correlation. The temperature prediction is carried out using bias-compensated long short-term memory (BC–LSTM) after selecting significant features, and the teamwork optimization algorithm (TOA) is used as the training algorithm to compensate for the bias error that occurs due to nonlinearity in the data. Moreover, the classification of sensors has been done using the proposed TOA-LSTM to identify the best sensors for critical space applications. The performance of proposed model is analysed using evaluation metrics such as accuracy, True Positive rate (TPR), True Negative rate (TNR), False Positive rate (FPR), mean squared error (MSE), mean absolute error (MAE) and root-mean-squared error (RMSE). The experimental investigation states that the proposed approach attains accuracy, TPR, TNR, and FPR with values of 0.960, 0.966, 0.949 and 0.0511, respectively.</p></div>","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":"142859708","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":"Torsional four-fermion interaction and the Raychaudhuri equation","authors":"Shibendu Gupta Choudhury,&nbsp;Sagar Kumar Maity,&nbsp;Amitabha Lahiri","doi":"10.1140/epjc/s10052-024-13618-4","DOIUrl":"10.1140/epjc/s10052-024-13618-4","url":null,"abstract":"<div><p>Intrinsic spin of fermions can generate torsion in spacetime. This torsion is a non-propagating field that can be integrated out, leaving an effective non-universal four-fermion interaction. This geometrical interaction affects fermions inside a matter distribution and can be expected to become stronger as the density grows. We investigate the role of this interaction in a gravitationally collapsing fermionic distribution, by considering a statistical average of the interaction term which incorporates the effect of mixed vector and axial currents. We consider a gravitationally collapsing distribution of massive fermions, ignoring other interactions. Using simplified yet reasonable assumptions, we establish that the contribution can be attractive or repulsive depending on how torsion couples with different chiralities. Also, the interaction starts to dominate as the collapse proceeds, accelerating or decelerating the collapse depending on the relative signs of the geometrical interaction between different species of fermions.</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/s10052-024-13618-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859531","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":"Heavy (K^*) mesons with open charm from (KD^{(*)}D^*) interactions","authors":"Xiu-Lei Ren,&nbsp;K. P. Khemchandani,&nbsp;A. Martínez Torres","doi":"10.1140/epjc/s10052-024-13683-9","DOIUrl":"10.1140/epjc/s10052-024-13683-9","url":null,"abstract":"<div><p>In view of the recent discovery of <span>(T_{cc})</span>, which can be described as a <span>(DD^*)</span> molecular state, we perform a study of the <span>(KDD^*)</span> system, and its extension to studying <span>(KD^*D^*)</span>, where <span>(D^*D^*)</span> is bound as a spin 1 <span>(T_{cc})</span>-like state, to search for the possible existence of exotic mesons with the open flavors <i>ccs</i> being part of their quark configuration. Considering the additional attractive interactions present in the <i>KD</i> and <span>(KD^*)</span> subsystems, where the states <span>(D^*_{s0}(2317))</span> and <span>(D_{s1}(2460))</span> are generated, we solve the Faddeev equations considering the fixed-center approximation for the mentioned three-body systems and find the existence of two doubly charmed <span>(K^*)</span>-like mesons, <span>(K_{cc}^*(4309))</span> and <span>(K_{cc}^*(4449))</span>, with quantum numbers <span>(I(J^P)=1/2,(1^-))</span>. Considering the respective three-body thresholds of the two systems, both <span>(K_{cc})</span>-states are bound by around 60 MeV. An experimental confirmation will bring evidence for the existence of a degree of exoticity beyond charm +2.</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/s10052-024-13683-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859533","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":"Photobiology in Russia","authors":"A. A. Tsygankov,&nbsp;M. M. Borisova-Mubarakshina,&nbsp;E. S. Vysotsky,&nbsp;A. E. Solovchenko,&nbsp;N. V. Suvorov,&nbsp;V. V. Tuchin","doi":"10.1134/S0006350924700659","DOIUrl":"10.1134/S0006350924700659","url":null,"abstract":"<div><p>Photobiology is rapidly developing field of basic and applied research. The Russian Society for Photobiology (RSP) promotes creative activity and communication of researchers and practitioners in photobiology and related disciplines. The X Congress of the RSP took place in September 2023. The article provides definitions of photobiology, biophotonics, photobiotechnology, and bioluminescence. The history of the RSP is described in brief. The program and results of the X Congress are reviewed, including a summary of articles that are based on reports at the Congress and are the closest to biophysics.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"69 3","pages":"584 - 590"},"PeriodicalIF":4.033,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859638","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":"Spectroscopic diagnostics of eggshells plasma using LIBS with self-absorption correction in conjunction with WDXRF, EDS and FTIR techniques","authors":"Muhammad Fahad,&nbsp;Khizar Hussain Shah,&nbsp;Sajjad Ali,&nbsp;Muhammad Abrar","doi":"10.1140/epjd/s10053-024-00944-1","DOIUrl":"10.1140/epjd/s10053-024-00944-1","url":null,"abstract":"<div><p>Precise determination of heavy metals and trace elements in eggshells from conventional and organic poultry production systems is carried out using a two distinct CF-LIBS techniques, namely one-line calibration-free (OLCF) and self-calibration (SC) LIBS, coupled with XRD, WD-XRF, EDS and FTIR. A <i>Q</i>-switched Nd:YAG laser with a wavelength of 1064 nm, pulse duration of 9 ns and pulse energy of 126 mJ was used to generate plasma. Spectral analysis revealed Ca, Mg, S, Fe, Mn, Cr, Sr, Al, Cu, Ni, Na, and Li in both organic (OE) and regular (FE) chicken eggshells, whereas a heavy element Ba was only detected in OE emission spectra. A mean value of plasma temperature was calculated as 7500 ± 750 K using a Boltzmann plot in addition to Saha-Boltzmann plot approach with self-absorption corrections and used for calcium quantification, whereas electron number density value was calculated as 5.68 × 10¹⁶ cm⁻³. The concentration of major constituent Ca in OE versus FE determined by CF-LIBS techniques along with XRF and EDS was found as: OLCF-LIBS = 99.23% versus 99.11%, SC-LIBS = 99.78% versus 99.73%, XRF = 99.81% versus 99.76%, and EDS = 99.83% versus 99.89%. The results showed that SC-LIBS method is more accurate for precise compositional analysis and findings were close to that determined by XRF and EDS methods. The results further demonstrated LIBS capability to identify heavy metals and trace elements within eggshell samples accurately and hence, contributing to and advancing our understanding of the utilization of LIBS technique in this field.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div><div><p>Spectroscopic diagnostics of eggshells plasma using LIBS</p></div></div></figure></div></div>","PeriodicalId":789,"journal":{"name":"The European Physical Journal D","volume":"78 12","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Quasinormal modes of regular black holes with sub-Planckian curvature and Minkowskian core","authors":"Chen Tang,&nbsp;Yi Ling,&nbsp;Qing-Quan Jiang,&nbsp;Guo-Ping Li","doi":"10.1140/epjc/s10052-024-13699-1","DOIUrl":"10.1140/epjc/s10052-024-13699-1","url":null,"abstract":"<div><p>We investigate the perturbation of the scalar field as well as the electromagnetic field over a sort of regular black holes which are characterized by the sub-Planckian curvature and the Minkowskian core. Specifically, we compute the quasinormal modes (QNMs) by employing the pseudo-spectral method. The outburst of overtones is manifestly observed in the QNMs of these regular black holes, which can be attributed to the deviation of the Schwarzschild black hole by quantum effects of gravity. Furthermore, the QNMs under the perturbation of electromagnetic field exhibit smaller real and imaginary parts than those under scalar field perturbation. By comparing the QNMs of the regular black hole featured by Minkowskian core with those of Bardeen black hole featured by de Sitter core, we find they may be an effective tool to distinguish these BHs.</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/s10052-024-13699-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859724","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":"Enabling precise predictions for left-right symmetry at colliders","authors":"Jonathan Kriewald,&nbsp;Miha Nemevšek,&nbsp;Fabrizio Nesti","doi":"10.1140/epjc/s10052-024-13614-8","DOIUrl":"10.1140/epjc/s10052-024-13614-8","url":null,"abstract":"<div><p>We investigate the structure of the minimal left-right symmetric model that enables precise predictions in the gauge, scalar and neutrino sector. We revisit the complete set of mass spectra and mixings for the charged and neutral gauge bosons, would-be-Goldstones and gauge fixing, together with the ghost Lagrangian. In the scalar sector, we analytically re-derive all the massive states with mixings and devise a non-trivial physical input scheme, expressing the model couplings in terms of masses and mixing angles. Fermion couplings are also determined in closed form, including the Dirac mixing in the neutrino sector, evaluated explicitly using the Cayley–Hamilton theorem. These analytic developments are implemented in a comprehensive FeynRules model file. We calculate the one loop QCD corrections and provide a complete UFO file for NLO studies, demonstrated on relevant hadron-collider benchmarks. We provide various restricted variants of the model file with different gauges, massless states, neutrino hierarchies and parity violating <span>(g_L ne g_R)</span> gauge couplings.</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/s10052-024-13614-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859731","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}