Photoinduced Co/Ni-cocatalyzed Markovnikov hydroarylation of unactivated olefins with aryl bromides.

Transition-metal-catalyzed hydroarylation of unactivated alkenes via metal hydride hydrogen atom transfer (MHAT) is an attractive approach for the construction of C(sp2)-C(sp3) bonds. However, this kind of reaction focuses mainly on using reductive hydrosilane as a hydrogen donor. Here, a novel photoinduced Co/Ni-cocatalyzed Markovnikov hydroarylation of unactivated alkenes with aryl bromides using protons as a hydrogen source has been developed. This reaction represents the first example of photoinduced MHAT via a reductive route intercepting an organometallic coreactant. The key to this transformation was that the CoIII-H species was generated from the protonation of the CoI intermediate, and the formed CoIII-C(sp3) intermediate interacted with the organometallic coreactant rather than reacting with nucleophiles, a method which has been well developed in photoinduced Co-catalyzed MHAT reactions. This reaction is characterized by its high catalytic efficiency, construction of quaternary carbons, simple reaction conditions and expansion of the reactive mode of Co-catalyzed MHAT reactions via a reductive route. Moreover, this catalytic system could also be applied to complex substrates derived from glycosides.

Application of Second-Generation Sequencing Technology in Lower Respiratory Tract Infection.

BACKGROUND: Lower respiratory tract infection (LRTI) has long been an important threat to people's life and health, so the rapid diagnosis of LRTI is of great significance in clinical treatment. In recent years, the development of the sequencing technology provides a new direction for the rapid diagnosis of LRTI. In this review, the advantages and disadvantages of second-generation sequencing techniques represented by metagenomics next-generation sequencing (mNGS) and droplet digital polymerase chain reaction (ddPCR) in LRTI were reviewed. Furthermore, it offers insights into the future trajectory of this technology, highlighting its potential to revolutionise the field of respiratory infection diagnostics. OBJECTIVE: This review summarises developments in mechanistic research of second-generation sequencing technology their relationship with clinical practice, providing insights for future research. METHODS: Authors conducted a search on PubMed and Web of Science using the professional terms 'Lower respiratory tract infection' and 'droplet digital polymerase chain reaction' and 'metagenomics next generation sequencing'. The obtained literature was then roughly categorised based on their research content. Similar studies were grouped into the same sections, and further searches were conducted based on the keywords of each section. RESULTS: Different studies discussed the application of second-generation sequencing technology in LRTI from different angles, including the detection of pathogens of LRTI by mNGS and ddPCR, the prediction ability of drug-resistant bacteria, and comparison with traditional methods. We try to analyse the advantages and disadvantages of the second-generation sequencing technology by combing the research results of mNGS and ddPCR. In addition, the development direction of the second-generation sequencing technology is prospected.

DMXL2 is required for endocytosis and recycling of synaptic vesicles in auditory hair cells.

Ribbon synapses of inner hair cells are uniquely designed for ultrafast and indefatigable neurotransmission of the sound. The molecular machinery ensuring the efficient, compensatory recycling of the synaptic vesicles, however, remains elusive. This study showed that hair cell knockout of murine Dmxl2, whose human homolog is responsible for non-syndromic sensorineural hearing loss DFNA71, resulted in auditory synaptopathy by impairing synaptic endocytosis and recycling. The mutant mice in the C57BL/6J background of either sex had mild hearing loss with severely diminished wave-I amplitude of the auditory brainstem response. Membrane capacitance measurements of the inner hair cells revealed deficiency in sustained synaptic exocytosis and endocytic membrane retrieval. Consistent with the electrophysiological findings, 3D electron microscopy reconstruction showed reduced reserve pool of synaptic vesicles and endocytic compartments, while the membrane-proximal and ribbon-associated vesicles remain intact. Our results propose an important role of DMXL2 in hair cell endocytosis and recycling of the synaptic vesicles.Significance Statement The molecular basis underlying efficient recycling of the ribbon synaptic vesicles in cochlear hair cells remains elusive. In this study, investigation of a hair cell-specific knockout mouse for Dmxl2 identifies its import roles in endocytosis and recycling of the auditory synaptic vesicles. The mutant mice display auditory synaptopathy, a common feature for noise-induced hearing loss and age-related hearing loss. The inner hair cells show deficiency in sustained synaptic exocytosis and endocytic membrane retrieval with reduced reserve pool of synaptic vesicles and endocytic compartments. Our results provide new insights into the molecular machinery ensuring ultrafast and indefatigable neurotransmission of the sound.

Integrating LiDAR Sensor Data into Microsimulation Model Calibration for Proactive Safety Analysis.

Studies have shown that vehicle trajectory data are effective for calibrating microsimulation models. Light Detection and Ranging (LiDAR) technology offers high-resolution 3D data, allowing for detailed mapping of the surrounding environment, including road geometry, roadside infrastructures, and moving objects such as vehicles, cyclists, and pedestrians. Unlike other traditional methods of trajectory data collection, LiDAR's high-speed data processing, fine angular resolution, high measurement accuracy, and high performance in adverse weather and low-light conditions make it well suited for applications requiring real-time response, such as autonomous vehicles. This research presents a comprehensive framework for integrating LiDAR sensor data into simulation models and their accurate calibration strategies for proactive safety analysis. Vehicle trajectory data were extracted from LiDAR point clouds collected at six urban signalized intersections in Lubbock, Texas, in the USA. Each study intersection was modeled with PTV VISSIM and calibrated to replicate the observed field scenarios. The Directed Brute Force method was used to calibrate two car-following and two lane-change parameters of the Wiedemann 1999 model in VISSIM, resulting in an average accuracy of 92.7%. Rear-end conflicts extracted from the calibrated models combined with a ten-year historical crash dataset were fitted into a Negative Binomial (NB) model to estimate the model's parameters. In all the six intersections, rear-end conflict count is a statistically significant predictor (p-value < 0.05) of observed rear-end crash frequency. The outcome of this study provides a framework for the combined use of LiDAR-based vehicle trajectory data, microsimulation, and surrogate safety assessment tools to transportation professionals. This integration allows for more accurate and proactive safety evaluations, which are essential for designing safer transportation systems, effective traffic control strategies, and predicting future congestion problems.

Histone H3K18 and Ezrin Lactylation Promote Renal Dysfunction in Sepsis-Associated Acute Kidney Injury.

Histone lactylation is a metabolic stress-related histone modification. However, the role of histone lactylation in the development of sepsis-associated acute kidney injury (SA-AKI) remains unclear. Here, histone H3K18 lactylation (H3K18la) is elevated in SA-AKI, which is reported in this study. Furthermore, this lactate-dependent histone modification is enriched at the promoter of Ras homolog gene family member A (RhoA) and positively correlated with the transcription. Correction of abnormal lactate levels resulted in a reversal of abnormal histone lactylation at the promoter of RhoA. Examination of related mechanism revealed that histone lactylation promoted the RhoA/Rho-associated protein kinase (ROCK) /Ezrin signaling, the activation of nuclear factor-κB (NF-κB), inflammation, cell apoptosis, and aggravated renal dysfunction. In addition, Ezrin can undergo lactylation modification. Multiple lactylation sites are identified in Ezrin and confirmed that lactylation mainly occurred at the K263 site. The role of histone lactylation is revealed in SA-AKI and reportes a novel post-translational modification in Ezrin. Its potential role in regulating inflammatory metabolic adaptation of renal proximal tubule epithelial cells is also elucidated. The results provide novel insights into the epigenetic regulation of the onset of SA-AKI.

T cell-mediated tumor killing based signature to predict the prognosis and immunotherapy for glioblastoma.

Despite the significant advancements in cancer treatment brought by immune checkpoint inhibitors (ICIs), their effectiveness in treating glioblastoma (GBM) remains highly dissatisfactory. Immunotherapy relies on the fundamental concept of T cell-mediated tumor killing (TTK). Nevertheless, additional investigation is required to explore its potential in prognostic prediction and regulation of tumor microenvironment (TME) in GBM. TTK sensitivity related genes (referred to as GSTTKs) were obtained from the TISIDB. The training cohort was available from the TCGA-GBM, while the independent validation group was gathered from GEO database. Firstly, we examined differentially expressed GSTTKs (DEGs) with limma package. Afterwards, the prognostic DEGs were identified and the TTK signature was established with univariate and LASSO Cox analyses. Next, we examined the correlation between the TTK signature and outcome of GBM as well as immune phenotypes of TME. Furthermore, the evaluation of TTK signature in predicting the effectiveness of immunotherapy has also been conducted. We successfully developed a TTK signature with an independent predictive value. Patients who had a high score experienced a worse prognosis compared to patients with low scores. The TTK signature showed a strong positive association with the infiltration degree of immunocyte and the presence of various immune checkpoints. Moreover, individuals with a lower score exhibited increased responsiveness to ICIs and experienced improved prognosis. In conclusions, we successfully developed and verified a TTK signature that has the ability to predict the outcome and immune characteristics of GBM. Furthermore, the TTK signature has the potential to direct the personalized immunotherapy for GBM.

PagWOX11/12a from hybrid poplar enhances drought tolerance by modulating reactive oxygen species.

WOX11/12 is a homeobox gene of WOX11 and WOX12 in Arabidopsis that plays important roles in crown root development and growth. It has been reported that WOX11/12 participates in adventitious root (AR) formation and different abiotic stress responses, but the downstream regulatory network of WOX11/12 in poplar remains to be further investigated. In this study, we found that PagWOX11/12a is strongly induced by PEG-simulated drought stress. PagWOX11/12a-overexpressing poplar plantlets showed lower oxidative damage levels, greater antioxidant enzyme activities and reactive oxygen species (ROS) scavenging capacity than non-transgenic poplar plants, whereas PagWOX11/12a dominant repression weakened root biomass accumulation and drought tolerance in poplar. RNA-seq analysis revealed that several differentially expressed genes (DEGs) regulated by PagWOX11/12a are involved in redox metabolism and drought stress response. We used RT-qPCR and yeast one-hybrid (Y1H) assays to validate the downstream target genes of PagWOX11/12a. These results provide new insights into the biological function and molecular regulatory mechanism of WOX11/12 in the abiotic resistance processes of poplar.

H3K4me3-Mediated FOXJ2/SLAMF8 Axis Aggravates Thrombosis and Inflammation in ß2GPI/Anti-ß2GPI-Treated Monocytes.

Antiphospholipid syndrome (APS) is characterized by thrombus formation, poor pregnancy outcomes, and a proinflammatory response. H3K4me3-related monocytes activation are key regulators of APS pathogenesis. Therefore, H3K4me3 CUT&Tag and ATAC-seq are performed to examine the epigenetic profiles. The results indicate that the H3K4me3 signal and chromatin accessibility at the FOXJ2 promoter are enhanced in an in vitro monocyte model by stimulation with ß2GPI/anti-ß2GPI, which mimics APS, and decreases after OICR-9429 administration. Furthermore, FOXJ2 is highly expressed in patients with primary APS (PAPS) and is the highest in patients with triple-positive antiphospholipid antibodies (aPLs). Mechanistically, FOXJ2 directly binds to the SLAMF8 promoter and activates SLAMF8 transcription. SLAMF8 further interacts with TREM1 to stimulate TLR4/NF-κB signaling and prohibit autophagy. Knockdown of FOXJ2, SLAMF8, or TREM1 blocks TLR4/NF-κB and provokes autophagy, subsequently inhibiting the release of inflammatory and thrombotic indicators. A mouse model of vascular APS is established via ß2GPI intraperitoneal injection, and the results suggest that OICR-9429 administration attenuates the inflammatory response and thrombus formation by inactivating FOXJ2/SLAMF8/TREM1 signaling. These findings highlight the overexpression of H3K4me3-mediated FOXJ2 in APS, which consequently accelerates APS pathogenesis by triggering inflammation and thrombosis via boosting the SLAMF8/TREM1 axis. Therefore, OICR-9429 is a promising candidate drug for APS therapy.

Effect of Potentilla anserina L. powder on gel properties and volatile flavor characteristics of silver carp surimi.

BACKGROUND: Potentilla anserina L. is rich in various nutrients, active ingredients and unique flavor, comprising a natural nutrition and health food. However, its application in aquatic food has been rarely reported. Therefore, the effects of Potentilla anserina L. powder (PAP) on gel properties and volatile flavor profile of silver carp surimi were investigated. RESULTS: The gel strength and water-holding capacity of the surimi gels were significantly improved (P < 0.05), and the whiteness and cooking loss of all the samples decreased slightly with the increase in PAP content. The addition of PAP shortened the relaxation time (T2) of the surimi gels and converted some of the free water into immobile or bound water, which resulted in a better immobilization of water in the surimi. Scanning electron microscopy images demonstrated that the network of surimi gels with PAP added was denser and had a smoother surface compared to the control. Volatile components (VCs) analysis showed that 33 VCs were identified in the surimi gel samples with different additions of PAP, among which aldehydes, alcohols and esters were the major VCs, accounting for more than 50% of the VCs in the surimi gels. PAP addition reduced the fishy and rancid flavor compounds in surimi gels, such as 1-propanol, 1-octen-3-ol, etc., and promoted the production of aldehydes, alcohols, esters and other flavor substances. CONCLUSION: These results of the present study provide theoretical support for the investigation and development of new nutrient-health-flavored surimi products. © 2024 Society of Chemical Industry.

Air-Stable Self-Driven UV Photodetectors on Controllable Lead-Free CsCu2I3 Microwire Arrays.

The rapid evolution of the Internet of Things has engendered increased requirements for low-cost, self-powered UV photodetectors. Herein, high-performance self-driven UV photodetectors are fabricated by designing asymmetric metal-semiconductor-metal structures on the high-quality large-area CsCu2I3 microwire arrays. The asymmetrical depletion region doubles the photocurrent and response speed compared to the symmetric structure device, leading to a high responsivity of 233 mA/W to 355 nm radiation. Notably, at 0 V bias, the asymmetric device produces an open-circuit voltage of 356 mV and drives to a short-circuit current of 372 pA; meanwhile, the switch ratio (Iph/Idark) reaches up to 103, indicating its excellent potential for detecting weak light. Furthermore, the device maintains stable responses throughout 10000 UV-light switch cycles, with negligible degradation even after 90-day storage in air. Our work establishes that CsCu2I3 is a good candidate for self-powered UV detection and thoroughly demonstrates its potential as a passive device.

Near-crash risk identification and evaluation for takeout delivery motorcycles using roadside LiDAR.

The proliferation of motorcycles in urban areas has raised concerns regarding traffic safety. However, traditional sensors struggle to obtain precise high-resolution trajectory data, which hinder the accurate identification and quantification of near-crash risks for takeout delivery motorcycles. To fill this gap, this study presents a novel approach utilizing roadside light detection and ranging (LiDAR) to identify and evaluate the risk of near crashes of takeout delivery motorcycles. First, a trajectory amendment method incorporating speed and steering angle was introduced to enhance the accuracy and continuity of the trajectory prediction. Second, a trajectory prediction method combining the steering intention and a repulsive force model was proposed for near-crash risk prediction. Subsequently, a near-crash identification method was developed that relied on the closest distance and risk radius. Finally, near-crash risk fields were constructed to quantify risk levels by leveraging velocity, position, and weight. The experimental results demonstrated 92.10 % accuracy in intention prediction, with mean absolute error (MAE) and root mean square error (RMSE) values of 0.53 m and 0.45 m, respectively. In addition to its higher accuracy, the proposed method makes it easier to quantify near-crash risk and supports a proactive approach for visualizing and analyzing traffic safety.

Switchable Two-Dimensional AND and Exclusive OR Operation Based on Dual-Wavelength Metasurfaces.

Logic operation serves as the foundation and core element of computing networks; it will bring huge vitality to advanced information processing with its adaptation in the optical domain. As fundamental logic operations, AND and exclusive OR (XOR) operations serve a multitude of purposes, such as their ability to cooperate in enabling image processing and interpretation. Here, we propose and experimentally demonstrate a wavelength multiplexed AND and XOR function based on metasurfaces. By combining two cosine gratings with distinct frequencies and an initial phase difference of π/2, we extract the similarities and differences between two input images simultaneously by illuminating them with 445 and 633 nm wavelengths. Additionally, we explore its potential in information encryption, where overall security is enhanced by distributing distinct parts of initial information and encoded keys to different receivers. This design possesses the benefits of convenient mode switching and high-quality imaging, facilitating advanced applications in pattern recognition, machine vision, medical diagnosis, etc.

ARID5B-mediated LINC01128 epigenetically activated pyroptosis and apoptosis by promoting the formation of the BTF3/STAT3 complex in ß2GPI/anti-ß2GPI-treated monocytes.

BACKGROUND: Alterations of the trimethylation of histone 3 lysine 4 (H3K4me3) mark in monocytes are implicated in the development of autoimmune diseases. Therefore, the purpose of our study was to elucidate the role of H3K4me3-mediated epigenetics in the pathogenesis of antiphospholipid syndrome (APS). METHODS: H3K4me3 Cleavage Under Targets and Tagmentation and Assay for Transposase-Accessible Chromatin were performed to determine the epigenetic profiles. Luciferase reporter assay, RNA immunoprecipitation, RNA pull-down, co-immunoprecipitation and chromatin immunoprecipitation were performed for mechanistic studies. Transmission electron microscopy and propidium iodide staining confirmed cell pyroptosis. Primary monocytes from patients with primary APS (PAPS) and healthy donors were utilised to test the levels of key molecules. A mouse model mimicked APS was constructed with beta2-glycoprotein I (ß2GPI) injection. Blood velocity was detected using murine Doppler ultrasound. RESULTS: H3K4me3 signal and open chromatin at the ARID5B promoter were increased in an in vitro model of APS. The epigenetic factor ARID5B directly activated LINC01128 transcription at its promoter. LINC01128 promoted the formation of the BTF3/STAT3 complex to enhance STAT3 phosphorylation. Activated STAT3 interacted with the NLRP3 promoter and subsequently stimulated pyroptosis and apoptosis. ARID5B or BTF3 depletion compensated for LINC01128-induced pyroptosis and apoptosis by inhibiting STAT3 phosphorylation. In mice with APS, ß2GPI exposure elevated the levels of key proteins of pyroptosis and apoptosis pathways in bone marrow-derived monocytes, reduced the blood velocity of the ascending aorta, increased the thrombus size of the carotid artery, and promoted the release of interleukin (IL)-18, IL-1ß and tissue factor. Patients with PAPS had the high-expressed ARID5B and LINC01128, especially those with triple positivity for antiphospholipid antibodies. Moreover, there was a positive correlation between ARID5B and LINC01128 expression. CONCLUSION: This study indicated that ARID5B/LINC01128 was synergistically upregulated in APS, and they aggravated disease pathogenesis by enhancing the formation of the BTF3/STAT3 complex and boosting p-STAT3-mediated pyroptosis and apoptosis, thereby providing candidate therapeutic targets for APS. HIGHLIGHTS: The H3K4me3 mark and chromatin accessibility at the ARID5B promoter are increased in vitro model mimicked APS. ARID5B-mediated LINC01128 induces pyroptosis and apoptosis via p-STAT3 by binding to BTF3. ARID5B is high- expressed in patients with primary APS and positively correlated with LINC01128 expression. OICR-9429 treatment mitigates pyroptosis and related inflammation in vivo and in vitro models mimicked APS.

Coagulation Status in Women with a History of Missed Abortion.

The purpose of this study assess the status of coagulation function in a large series of reproductive-age women with a history of missed abortion in China. Likewise, we want to explore the association between coagulation and missed abortions, in order to evaluate whether they could be used as early predictive factors for missed abortions. A total of 11,182 women who suffered from missed abortion from Peking University Third Hospital and 5298 healthy age-matched reproductive-age women were enrolled in our study. Coagulation function tests (prothrombin time, activated partial thromboplastin time), fibrinolysis status detection (fibrinogen, D-Dimer), anticoagulation function tests (protein C, protein S and antithrombin III), and lupus anticoagulants (LAC) were examined. In addition, platelet counts were detected by automated hematology analyzer. Platelet aggregation (PAgT) was tested by light transmission aggregometry (LTA). Compared with healthy reproductive-age women, the level of D-Dimer, dRVVT-R, PC, PAgT, and platelet count was higher, and the antithrombin III (AT-III) activity was lower in women with a history of missed abortion. (P < 0.05). A total of 13.1% patients with a history of missed abortion were positive for LAC, and platelet aggregation rates were increased in 47.4% patients. Moreover, multivariate logistic regression analysis showed that D-Dimer, dRVVT-R, AT-III, PC, and PAgT had significant predictive value for missed abortion. In addition, a model based on coagulation function tests for predicting missed abortion was developed. These findings provide evidence of hypercoagulability in patients with a history of missed abortion. Lupus anticoagulant, PAgT, and D-Dimer were the strongest predictors of missed abortion.was to.

Erianin suppressed lung cancer stemness and chemotherapeutic sensitivity via triggering ferroptosis.

The previous research has focused on the suppressive effects of Erianin on tumor progression, but its impact on cancer stemness has not been reported. This study aimed to investigate the effects of Erianin on lung cancer stemness. First, we screened various concentrations Erianin to ensure that it did not affect lung cancer cell viability. Subsequently, we found that Erianin significantly attenuated lung cancer stemness through various analyses, including qRT-PCR, western blot, sphere-formation, and ALDH activity detection. Furthermore, Erianin was shown to enhance chemosensitivity of lung cancer cells. Mechanistically, three inhibitors (cell apoptosis inhibitor, necrosis inhibitor, and ferroptosis inhibitor) were added into lung cancer cells with Erianin treatment, respectively, and we found that Erianin mainly suppressed lung cancer stemness through ferroptosis. Taken together, this study reveals that Erianin has the potential to suppress lung cancer stemness and could be a valuable chemotherapeutic enhancer for lung cancer.

miRNA-130a-3p/CPEB4 Axis Modulates Glioblastoma Growth and Progression.

Glioblastoma is the most frequent form of malignant brain tumor. Cytoplasmic polyadenylation element binding protein 4 (CPEB4) is overexpressed and involved in the tumorigenesis and metastasis of glioblastoma. miR-130a-3p has been revealed to be aberrantly expressed in tumors and has aroused wide attention. In present study, we would like to investigate the effect and potential mechanism of miR-130a-3p on the proliferation and migration in glioblastoma. The relative expression levels of miR-130a-3p and CPEB4 in glioblastoma cell lines were detected by real-time quantitative polymerase chain reaction. Cell viability and migration were detected by methylthiazolyl tetrazolium assay and transwell assay, and cell cycle analysis was detected by flow cytometry. The expression of CPEB4 protein and epithelial-mesenchymal transition associated markers were detected by western blot. Bioinformatics and luciferase activity analysis were used to verify the targeting relationship between miR-130a-3p and CPEB4. We observed that the expression of CPEB4 was upregulated while that of miR-130a-3p was downregulated in glioblastoma cell lines. CPEB4 was validated as a target of miR-130a-3p by luciferase activity assay. Increased levels of miR-130a-3p inhibited the proliferation and migration of the glioblastoma cells and the overexpression of miR-130a-3p inhibited epithelial-mesenchymal transition. However, CPEB4 overexpression resisted the inhibitory effects of miR-130a-3p. Our study elucidates CPEB4 is upregulated because of the downregulated miR-130a-3p in glioblastoma, which enhances the glioblastoma growth and migration, suggesting a potential therapeutic target for the disease.

Perovskite single-pixel detector for dual-color metasurface imaging recognition in complex environment.

Highly efficient multi-dimensional data storage and extraction are two primary ends for the design and fabrication of emerging optical materials. Although metasurfaces show great potential in information storage due to their modulation for different degrees of freedom of light, a compact and efficient detector for relevant multi-dimensional data retrieval is still a challenge, especially in complex environments. Here, we demonstrate a multi-dimensional image storage and retrieval process by using a dual-color metasurface and a double-layer integrated perovskite single-pixel detector (DIP-SPD). Benefitting from the photoelectric response characteristics of the FAPbBr2.4I0.6 and FAPbI3 films and their stacked structure, our filter-free DIP-SPD can accurately reconstruct different colorful images stored in a metasurface within a single-round measurement, even in complex environments with scattering media or strong background noise. Our work not only provides a compact, filter-free, and noise-robust detector for colorful image extraction in a metasurface, but also paves the way for color imaging application of perovskite-like bandgap tunable materials.

Crash frequency prediction based on extreme value theory using roadside lidar-based vehicle trajectory data.

Crash prediction models (CPMs) are mostly developed using statistical or data-driven methods that rely on observed crashes. However, the historical crash records can be unreliable due to availability and data quality issues. Near-crashes based CPMs offer a proactive approach to predict crash frequencies prior to the occurrence of crashes. Surrogate safety measures can be used to identify near-crashes from road user trajectories. Roadside LiDAR offers an innovative approach to collect vehicle trajectory data at a microscopic resolution with high accuracy providing detailed information of all road user movements. This study presents a methodology to identify near-crashes from Roadside LiDAR based vehicle trajectory data using the surrogate indicators: TTC (Time to Collision), PET (Post Encroachment Time), ACT (Anticipated Collision Time) and MaxD (Maximum Deceleration). Additionally, time-based, and evasive-action-based surrogate measures are combined as different pairs to obtain crash probabilities using extreme value theory (EVT). The study results show that the bivariate EVT model displays a better fit to conflict extremes, predicting crash frequencies better than the univariate model. Likewise, while the bivariate model with ACT and MaxD pair performed the best in terms of accuracy, the TTC and MaxD pair was able to reflect the relative threat levels at the study intersections. Overall, the methodology lays ground for using roadside lidar based trajectory data for proactive safety analysis of signalized intersections.