The Piezo family of mechanosensitive ion channels serves as the primary molecular transducer that converts mechanical stimuli into electrochemical signals in living organisms, marking a pivotal breakthrough in mechanobiology. This review systematically summarizes recent advances in Piezo channel research, with a specific focus on the Piezo1, from the novel perspective of physical field therapy. We first describe the unique trimeric "propeller-nano-bowl" architecture of Piezo channels and their gating mechanisms, which rely on membrane tension sensing and a lever-like mechanical amplification principle. Next, we comprehensively explore the physiological roles of Piezo-mediated signaling in core systems, including the skeletal, cardiovascular, nervous, and immune systems, and elucidate their pathophysiological implications in diseases such as genetic disorders, osteoarthritis, and cancer. Finally, we highlight cutting-edge bioelectromagnetic intervention strategies, including the use of ultrasound and magnetic fields for non-invasive modulation of Piezo activity, as well as the application of piezoelectric biomaterials designed to mimic Piezo functions for tissue regeneration, neuromodulation, and targeted drug delivery.

The Large Hadron Collider (LHC) started the Run 3 operation in 2022, and the peak instantaneous luminosity in Run 3 may reach 3 x 10^34 cm-2s-1. The ATLAS Monitored Drift Tube (MDT) chambers are the main component of the precision tracking system in the ATLAS muon spectrometer. It is important to understand any potential issues with the MDT Front-End (FE) readout electronics for an expected level-1 (L1) trigger rate of 100 kHz and a complex deadtime of over 5% for Run 3 operations. We use raw data collected in 2022 to emulate the expected hit rates in MDT chambers and perform a realistic simulation on the ATLAS Muon TDC (Time-to-Digital Converter) (AMT) chip with the current configuration. We study the AMT chip performances by analyzing the trigger/L1/readout buffer occupancies and hit loss fractions under different luminosities with L1 rate of 100 kHz by using the Modelsim software. The hit loss fraction of the hottest MDT chamber (BIL3C05) is lower than 5% due to FE readout, even at a luminosity of 5.01 x 10^34 cm-2s-1 with a deadtime of 5% and a L1 rate of 100 kHz, indicating that AMT can operate under Run 3 conditions without problems. The MDT trigger and readout electronics will be replaced for triggerless readout during High-Luminosity LHC (HL-LHC) runs. We also simulate the AMT behavior in the triggerless mode up to 7.44 x 10^34 cm-2s-1 and propose possible AMT configurations in case some FE electronics could not be replaced during the long shutdown 3 (LS3).

Charged particle precipitation typically manifests as a gradual increase and decrease of flux observed by space detectors. Cases with rapid flux variation are very rare, while periodic events are even more extraordinary. These oscillating particle precipitation (OPP) events are usually attributed to the bounce motion of electrons probably induced by lightning. However, the origin of these oscillation events is still on debate. Here we report three peculiar charged particle precipitation events detected by GECAM during a geomagnetic storm on March 21, 2024, with two exhibiting significant periodicity. These events were observed around the same region during three consecutive orbits with a life time of more than 3.5 h. Through comprehensive temporal and spectral analyses, we find that one of the OPP events exhibited a transition in spectral lag of mini-pulses, shifting from “softer-earlier” to “softer-later” while showing no significant time evolution in overall frequency characteristics, and that there is no association found between these two OPP events and lightning activity nearby. Finally, we discussed possible scenarios to explain these GECAM-detected OPP events, and we found that they may represent a new type of particle precipitation event or a peculiar lightning-induced electron precipitation (LEP).

The prompt emission of gamma-ray bursts (GRBs) could be composed of different spectral components, such as a dominant nonthermal Band component in the keV–MeV range, a subdominant quasi-thermal component, and an additional hard nonthermal component extending into the GeV range. The existence and evolutionary behaviors of these components could provide essential constraints on physical models, such as ejecta composition and dissipation processes. Although numerous GRBs have been found to exhibit one or two spectral components, reports of GRBs containing all three components remain rare. In this Letter, based on the joint observations of GRB 240825A from multiple gamma-ray telescopes, we conduct a comprehensive temporal and spectral analysis to identify the presence and evolution of all three components. The bulk Lorentz factor of this bright and relatively short-duration burst is independently obtained from the thermal and hard nonthermal components, supporting a jet penetration scenario. The multisegment broken power-law feature observed in the flux lightcurves suggests the presence of an early afterglow in the keV–MeV band and hints at a possible two-jet structure. Furthermore, the observed transition from positive to negative on the spectral lag can be interpreted as misalignment in the cross-correlation function analysis of pulses, which is caused by evolution of the soft and hard components.

Gamma-ray bursts (GRBs) are luminous stellar explosions characterized by the ejection of relativistic jets. This work proposes a novel paradigm to study these GRB jets. By analyzing the timing information of prompt pulses and X-ray flares, in conjunction with the multiwavelength afterglow observations, we identify three distinct jets in the extraordinary GRB 060729, with initial bulk Lorentz factors ranging from approximately 20 to 80, smaller than typical values of >100. These three jets undergo two successive collisions, producing the observed pair of X-ray flares. Following these interactions, the system evolves into a fast, narrow jet and a slower, hollow jet that continues to propagate in the circumburst medium, evidenced by the notable twin bumps observed in the X-ray and optical afterglow of GRB 060729. Our findings demonstrate that the timing of the early emission enables us to measure the velocities of the GRB jets. The proposed paradigm enhances our understanding of jet dynamics and shock interactions and serves as a powerful tool for probing the physics of the central engine with the expanded sample in the current golden era of GRB research.

To develop a detection system for Klebsiella pneumoniae carbapenemase (KPC) and provide a reference for clinical prevention and control of nosocomial infections caused by multidrug-resistant K. pneumoniae. The KPC resistance gene was amplified by PCR. Guided by crRNA, Cas12a specifically identified the resistance gene and activated its trans-cleavage activity. In the detection system, a fluorescence probe was cleaved by activated Cas12a, and the fluorescence signal was measured using a microplate reader. Under optimized conditions, the fluorescence signal appeared within 12 min, peaked at 40 min and completed detection within 60 min. sensitivity: 91.2%, specificity: 84.1%, detection limit: 0.01 ng/μl. The samples were examined by fluorescence-CRISPR Cas12a and PCR. The coincidence rate was 85.9%, Kappa value was 0.8. The ROC curve analysis revealed an AUC of 0.916, with an optimal cutoff value of 1.55, sensitivity of 91.2%, and specificity of 84.1%. The CRISPR Cas12a detection of carbapenem-resistant K. pneumoniae (CRKP) demonstrates high sensitivity, specificity, and broad applicability. This method requires standard molecular biology equipment but does not rely on sequencing-based platforms.

Type I gamma-ray bursts (GRBs) are believed to originate from compact binary mergers usually with a duration of main emission less than 2 s. However, recent observations of GRB 211211A and GRB 230307A indicate that some merger-origin GRBs could last much longer. Since they show strikingly similar properties (indicating a common mechanism), which are different from the classic “long”-short burst (e.g., GRB 060614), we find they form an interesting subclass of type I GRBs, and we suggest to name them as type IL GRB. We find that the prompt emission of type IL GRB is composed of three episodes: (1) a precursor followed by a short quiescent (or weak emission) period, (2) a long-duration main emission, and (3) an extended emission. With this burst pattern, a good candidate, GRB 170228A, was found in the Fermi/Gamma-ray Burst Monitor archive data. Temporal and spectral analyses indeed show that GRB 170228A falls in the same group with GRB 211211A and GRB 230307A in many diagnostic figures. Thus, this burst pattern could be a good reference for rapidly identifying type IL GRBs and very helpful for conducting low-latency follow-up observation. We estimated the occurrence rate and discussed the physical origins and implications for the three emission episodes of type IL GRBs. Our analysis suggests the premerger precursor model, especially the magnetar super flare model, is more favored for type IL GRBs. More observations in multiwavelength and multimessenger are required to deepen our understanding of this subclass of GRB.

As of 2023 December, the high-energy telescope (HE) of Insight-HXMT has detected 72 short-duration gamma-ray bursts (sGRBs), which may be related to binary compact star mergers. In this work, we locate these sGRBs by adopting an enhanced time-delay localization method based on the Li modified cross-correlation function (Li-CCF), jointly with Insight-HXMT/HE, Gravitational-wave high-energy Electromagnetic Counterpart All-sky Monitor, Fermi/Gamma-ray Burst Monitor (GBM), INTEGRAL/SPI-ACS, and Konus-Wind. The results indicate that joint localization improves accuracy (3 σ ) by an average of 59% compared to results with GBM alone, and the participation of HXMT improves the joint localization accuracy (3 σ ) by an average of 47%. The median and minimum of the joint localization area are 229 and 0.2 square degrees, respectively. We also propose a method to effectively locate those bursts (e.g., GRB 200415A) for which HE suffered from data saturation. In addition, we investigate whether the multiple annuli are independent when there is overlapping data through simulations. The results show that as long as the data from both satellites used have not been overlapped at the same time, the localization results (annuli) are independent. Finally, we verify the robustness of the results by comparing the precise localization bursts observed by Swift/Burst Alert Telescope, as well as publishing the high-time-resolution light curves, orbits and localization probability sky maps in Hierarchical Equal Area Isolatitude Pixelization format files on the website https://ihepbox.ihep.ac.cn/ihepbox/index.php/s/LO1eRZ0SBIEiBIg .

Artificial Kitaev chains (AKCs), formed of quantum dot-superconductor linear arrays, provide a promising platform for hosting Majorana bound states (MBSs) and implementing topological quantum computing. The main challenges along this research direction include the tuning of AKCs for hosting MBSs and the readout of the parity of the chains. In this work, we present a step-by-step procedure for tuning a three-site AKC to its sweet spots based on the spectra of a transmon circuit which is integrated with the chain for the purpose of reading out the parity of the chain. The signatures of the transmon's plasma modes in each step, in particular those related to the appearance of MBSs in the chain, will be given. We find that the sweet spots in a three-site AKC can be classified into three types based on the relative strengths of the elastic cotunneling (ECT) and crossed Andreev reflection (CAR): ECT-dominated sweet spots, genuine sweet spots, and CAR-dominated sweet spots. We show that the ECT-dominated and CAR-dominated sweet spots can be more conveniently accessed and utilized in transmon-based measurements.

Gamma-ray bursts (GRBs) are luminous stellar explosions characterized by the ejection of relativistic jets. This work proposes a novel paradigm to study these GRB jets. By analyzing the timing information of prompt pulses and X-ray flares, in conjunction with the multi-wavelength afterglow observations, we identify three distinct jets in the extraordinary GRB 060729, with initial bulk Lorentz factors ranging from approximately 20 to 80, smaller than typical values of $> 100$. These three jets undergo two successive collisions, producing the observed pair of X-ray flares. Following these interactions, the system evolves into a fast, narrow jet and a slower, hollow jet that continues to propagate in the circumburst medium, evidenced by the notable twin bumps observed in the X-ray and optical afterglow of GRB 060729. Our findings demonstrate that the timing of the early emission enables us to measure the velocities of the GRB jets. The proposed paradigm enhances our understanding of jet dynamics and shock interactions and serves as a powerful tool for probing the physics of the central engine with the expanded sample in the current golden era of GRB research.

As one of three primary scientific payloads of Insight-Hard X-ray Modulation Telescope (Insight-HXMT), the High Energy X-ray telescope (HE) consists of 18 NaI/CsI phoswich detectors, and the CsI detectors can detect gamma-rays that penetrate the satellite from all directions, with an energy range of about 60 keV to 3.2 MeV and a total geometric area of about 5100 cm2. These characteristics make the CsI detectors suitable for monitoring GRBs and other high-energy transients. Initial calibration and performance studies of the CsI detectors’ instrumental response were conducted during the early operation phase before 2020. In this work, we refine the cross-calibration of CsI detectors using a large sample of 85 bright GRBs. Our analysis reveals that the effective area is inversely proportional to the incident angle (θ), with no correlation observed with the azimuthal angle (ϕ). We subsequently incorporated this relationship into the calibration database to correct for systematic biases in the initial calibration. Furthermore, we demonstrate that joint spectral analyses incorporating CsI data provide better constraints on high-energy spectral parameters for most GRBs. Additionally, we evaluate, for the first time, the energy response of CsI detectors for pointing observation by measuring the Crab Nebula using the Earth occultation technique. This effort extends the energy range of the Insight-HXMT telescope from 1–250 to 1–750 keV for pointing observations. Those results show that the spectra measured by CsI detectors are consistent with other well-calibrated instruments, validating the reliability and accuracy of the CsI detectors’ performance. Our work will contribute to Insight-HXMT’s capacity to generate more scientific outputs in the field of time-domain astronomy.

PURPOSE:This study aims to enhance gamma passing rate (GPR) classification by integrating plan complexity signature, dosiomics signature, and comprehensive plan parameters, and to validate this method using data from different linear accelerators (LINACs). METHODS:This study included 235 volumetric modulated arc therapy (VMAT) treatment plans delivered using the TrueBeam LINAC as the primary dataset, along with 47 plans from the VitalBeam LINAC for external validation. The primary dataset was split into training (N = 166) and test (N = 69) subsets. Extracted features included 47 plan complexity metrics, 851 dosiomics features, and 20 plan parameters. Plan complexity score (PCscore) and dosiomics score (Doscore) were derived using the least absolute shrinkage and selection operator (LASSO). Four classification models were developed by combining PCscore, Doscore, and plan parameters according to a gamma criterion of 2 %/2 mm (γ2%/2 mm). A nomogram was constructed to combine these signatures with plan parameters. Model performance was evaluated using receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA). RESULTS:The combined model incorporating PCscore, Doscore, and plan parameters exhibited high discriminative power, with areas under the curve (AUC) of 0.894, 0.899, and 0.904 for the training, test, and external datasets, respectively. At γ3%/2 mm, the model maintained robust performance with AUCs of 0.842 and 0.833 in the test and external datasets. Calibration curves and DCA validated the model's effectiveness. CONCLUSIONS:Integrating plan complexity and dosiomics signatures with key plan parameters significantly improves GPR classification for VMAT treatment plans, offering a robust approach for patient-specific quality assurance (PSQA).

In this new era of time-domain and multi-messenger astronomy, various new transients and new phenomena are constantly being discovered thanks to the rapid advances in observations, which provide the excellent opportunity to study the physics in the extreme environments. The enhanced X-ray Timing and Polarimetry mission (eXTP), planned to be launched in 2030, has several key advantages, including advanced polarimetry, high sensitivity large effective area, and wide energy range coverage, which make it a groundbreaking project in high-energy astrophysics. In this article, we briefly introduce the potential time-domain and multi-messenger targets for eXTP, including gravitational-wave (GW) counterparts, gamma-ray bursts (GRBs), magnetars and fast radio bursts (FRBs), tidal disruption events (TDEs), supernovae, high energy neutrinos and TeV active galactic nucleus (AGNs), and so on. We discuss the advantages of future eXTP observations for detecting these sources, their detection capabilities, the abilities to distinguish theoretical models, and their applications in gravity and cosmology.

The long-term evolution of relativistic jets in gamma-ray bursts (GRBs), particularly from days to months post-burst, remains a fundamental puzzle in astrophysics. Here, we report our very long baseline interferometry observation of the brightest GRB 221009A from 5 to 26 days post-burst. Combined with released data, we uncover a remarkable two-stage evolution of the jet lateral size. The jet size initially grew slowly but later expanded rapidly, challenging conventional scenarios. The slow-evolving stage provides a robust lower limit on the jet opening angle and direct evidence of jet propagation in the uniform interstellar medium at this period. The synergy analysis of the whole jet size evolution and multi-wavelength emissions uncovers that GRB 221009A harbors an ultra-narrow jet (with a half-opening angle ≃ 0.01-0.03 radian) that propagates through a wind-like medium before encountering the interstellar medium, which finally undergoes lateral spreading after significant deceleration. These findings provide crucial new insights into relativistic jet dynamics and establish GRB 221009A as a unique case study for understanding the complex physics of GRB outflows.

The Gravitational Wave High-energy Electromagnetic Counterpart All-sky Monitor (GECAM) is a dedicated mission consisting of multiple instruments on different spacecraft to monitor gamma-ray transients. To meet the requirement of GECAM, we developed the Energetic Transients Joint Analysis System for Multi-INstrument (ETJASMIN) pipeline, which has been extended to incorporate other instruments (such as Fermi-GBM, SVOM/GRM). In this work, we introduce the ETJASMIN pipeline with focus on the search, verification, and classification of gamma-ray transients (especially weak bursts) using data from GECAM-B, GECAM-C, and Fermi-GBM. For this pipeline, we implement a coherent algorithm to search for simultaneous signals in the light curves of multiple instruments, conduct a series of Monte Carlo simulations, and validate the pipeline performance with in-flight observation data. The results demonstrate that ETJASMIN can yield not only higher significance of burst search but also more reliable verification and classification of bursts jointly with multiple instruments compared to those derived with an individual instrument. Thus, ETJASMIN is particularly suitable for the exploitation of gamma-ray transients associated with multimessenger multiwavelength sources.

The Gravitational wave burst high-energy Electromagnetic Counterpart All-sky Monitor(GECAM) is a dedicated mission for monitoring high-energy transients. Here we report the design of the GECAM Scientific Ground Segment(GSGS) in terms of the scientific requirements, including the architecture, the external interfaces, the main function, and workflow. Judging from the analysis and verification results during the commissioning phase,the GSGS functions well and is able to monitor the status of the payloads, adjust the parameters, develop the scientific observation plans, generate the scientific data products, analyze the data, etc. Thus, the on-orbit operation and scientific researches of GECAM are guaranteed.

The power density spectrum (PDS) is a powerful tool to study light curves of gamma-ray bursts (GRBs). We show the average PDS and individual PDS analysis with GRB data from the Hard X-ray Modulation Telescope (also named Insight-HXMT). The values of the power-law index of the average PDS ( alpha P ) for long GRBs (LGRBs) vary from 1.58 to 1.29 (for 100-245, 245-600, and 600-2000 keV). The Insight-HXMT data allow us to extend the energy of the LGRBs up to 2000 keV, and a relation between alpha P and energy E is obtained: alpha Pproportional to E-0.09 (8-2000 keV). We first systematically investigate the average PDS and individual PDSs for short GRBs (SGRBs), and obtain alpha Pproportional to E-0.07 (8-1000 keV), where the values of alpha P vary from 1.86 to 1.34. The distribution of the power-law index of an individual PDS (alpha) of an SGRB is consistent with that of an LGRB, and the alpha value for the group with a dominant timescale (the bent power law) is higher than that for the group with no dominant timescale (the single power law). Both LGRBs and SGRBs show similar alpha and alpha P , which indicates that they may be the result of similar stochastic processes. Typical values of the dominant timescale tau for LGRBs and SGRBs are 1.58 s and 0.02 s, respectively. It seems that tau varies in proportion to the duration of GRBs T 90, with a relation tau proportional to T900.86 . The GRB light curve may result from superposing a number of pulses with different timescales. No periodic or quasi-periodic signal above the 3 sigma significance threshold is found in our sample.

Abstract Gamma-ray bursts (GRBs) are the most luminous stellar explosions in the Universe, in which relativistic jets are involved. GRB 221009A stands out as the brightest GRB ever observed, providing a unique opportunity to probe the properties of an ultrarelativistic jet. Here, we report our very long baseline interferometry (VLBI) observation on the extremely bright GRB 221009A from 5 to 26 days after the burst. An intriguing two-stage evolution of the source size of this GRB is revealed by combining this data with later VLBI data. The observed size initially increases slowly as ~ tobs0.15 during the first month, but expands with a much faster rate as ~ tobs2.21 at later times. This unprecedented two-stage size evolution cannot be explained by the existing theoretical models invoking a non-spreading top-hat jet or a conventional structured jet and thus challenges our current understanding of this GRB jet. The transition may suggest the beginning of rapid sideways expansion of a narrow jet as the relativistic jet decelerates enough or the emergence of a new emission component. Our findings unveil the complex jet dynamics of GRB 221009A, highlighting the necessity of direct measurements of the size and geometry of the emission region in studying low-redshift GRBs in the multi-wavelength era.

Fast and reliable localization of high-energy transients is crucial for characterizing the burst properties and guiding the follow-up observations. Localization based on the relative counts of different detectors has been widely used for all-sky gamma-ray monitors. There are two major methods for this counts distribution localization: $\chi^{2}$ minimization method and the Bayesian method. Here we propose a modified Bayesian method that could take advantage of both the accuracy of the Bayesian method and the simplicity of the $\chi^{2}$ method. With comprehensive simulations, we find that our Bayesian method with Poisson likelihood is generally more applicable for various bursts than $\chi^{2}$ method, especially for weak bursts. We further proposed a location-spectrum iteration approach based on the Bayesian inference, which could alleviate the problems caused by the spectral difference between the burst and location templates. Our method is very suitable for scenarios with limited computation resources or time-sensitive applications, such as in-flight localization software, and low-latency localization for rapid follow-up observations.

Realtime trigger and localization of bursts are the key functions of GECAM, an all-sky gamma-ray monitor launched on 2020 December 10. We developed a multifunctional trigger and localization software operating in the CPU of the GECAM Electronic Box. This onboard software has the following features: high trigger efficiency for real celestial bursts with a suppression of false triggers caused by charged particle bursts and background fluctuation, dedicated localization algorithm optimized for both short and long bursts, and low time latency of the trigger information which is downlinked through the Global Short Message Communication service of the global BeiDou navigation system. This paper provides a detailed description of the design and development of the trigger and localization software system for GECAM. It covers the general design, workflow, the main functions, and the algorithms used in the system. The paper also includes on-ground trigger tests using simulated gamma-ray bursts generated by a dedicated X-ray tube, as well as an overview of the performance for real celestial bursts during its in-orbit operation.