Modulating the ESIPT Mechanism and Luminescence Characteristics of Two Reversible Fluorescent Probes by Solvent Polarity: A Novel Perspective.

As reversible fluorescent probes, HTP-1 and HTP-2 have favourable applications for the detection of Zn2+ and H2S. Herein, the impact of solvent on the excited-state intramolecular proton transfer (ESIPT) of HTP-1 and HTP-2 was comprehensively investigated. The obtained geometric parameters and infrared (IR) vibrational analysis associated with the intramolecular hydrogen bond (IHB) indicated that the strength of IHB for HTP-1 was weakened in the excited state. Moreover, structural torsion and almost no ICT behaviour indicated that the ESIPT process did not occur in HTP-1. Nevertheless, when the 7-nitro-1,2,3-benzoxadiazole (NBD) group replaced the H atom, the IHB strength of HTP-2 was enhanced after photoexcitation, which inhibited the twisting of tetraphenylethylene, thereby opening the ESIPT channel. Notably, hole-electron analysis and frontier molecular orbitals revealed that the charge decoupling effect was the reason for the fluorescence quenching of HTP-2. Furthermore, the potential energy curves (PECs) revealed that HTP-2 was more inclined to the ESIPT process in polar solvents than in nonpolar solvents. With a decrease in solvent polarity, it was more conducive to the ESIPT process. Our study systematically presents the ESIPT process and different detection mechanisms of the two reversible probe molecules regulated by solvent polarity, providing new insights into the design and development of novel fluorescent probes.

Personalised graded psychological intervention on negative emotion and quality of life in patients with breast cancer.

BACKGROUND: Psychological factors are a risk factor for the incidence of breast cancer and have a significant impact on patient prognosis. OBJECTIVE: The present study aims to investigate the effects of personalised graded psychological intervention on negative emotion and quality of life in patients with breast cancer. METHODS: A total of 200 patients with breast cancer were randomly divided into two groups: an experimental group (n= 100) and control group (n= 100). Both groups received routine nursing care. The experimental group received personalised graded psychological intervention care, and the control group received routine nursing measures. After 2 months of standard treatment, the patients' quality of life and negative emotions were evaluated using the self-rating depression scale (SDS), self-rating anxiety scale (SAS), social support rating scale (SSRS) and quality of life measurement scale (FACT-B) scoring criteria. RESULTS: There were no significant differences in the general data between the two groups (p> 0.05). Furthermore, there were no significant differences in the SDS, SAS, SSRS and FACT-B scores between the two groups before personalised graded psychological intervention (p> 0.05). After the intervention, the experimental group exhibited an improved nursing effect compared with the control group. The SDS and SAS scores were lower in the experimental group than in the control group (p< 0.05); after the intervention, the SDS and SAS scores were significantly lower in the experimental group than in the control group (p< 0.05). The SSRS and FACT-B scores were higher in the experimental group than in the control group (p< 0.05), and the experimental group's post-intervention SSRS and FACT-B scores were significantly higher than before the intervention (p< 0.05). CONCLUSIONS: The use of personalised graded psychological intervention for the nursing of patients with breast cancer in clinical practice can significantly reduce patients' negative emotions as well as improve positive emotions and quality of life; thus, this method can be popularised in the nursing process.

Comparative efficacy of robotic-assisted and freehand techniques for pedicle screw placement in spinal disorders: a meta-analysis and systematic review.

The efficacy and safety of robotic-assisted pedicle screw placement compared to traditional fluoroscopy-guided techniques are of great interest in the field of spinal surgery. This systematic review and meta-analysis aimed to compare the outcomes of these two methods in patients with spinal diseases. Following the PRISMA guidelines, we conducted a systematic search across PubMed, Embase, Web of Science, and Cochrane Library. We included randomized controlled trials comparing robotic-assisted and fluoroscopy-guided pedicle screw placement in patients with spinal diseases. Outcome measures included the accuracy of pedicle screw placement, postoperative complication rates, intraoperative radiation exposure time, and duration of surgery. Data were analyzed using Stata software. Our analysis included 12 studies. It revealed significantly higher accuracy in pedicle screw placement with robotic assistance (odds ratio [OR] = 2.83, 95% confidence interval [CI] = 2.20-3.64, P < 0.01). Postoperative complication rates, intraoperative radiation exposure time, and duration of surgery were similar between the two techniques (OR = 0.72, 95% CI = 0.31 to 1.68, P = 0.56 for complication rates; weighted mean difference [WMD] = - 0.13, 95% CI = - 0.93 to 0.68, P = 0.86 for radiation exposure time; WMD = 0.30, 95% CI = - 0.06 to 0.66, P = 0.06 for duration of surgery). Robotic-assisted pedicle screw placement offers superior placement accuracy compared to fluoroscopy-guided techniques. Postoperative complication rates, intraoperative radiation exposure time, and duration of surgery were comparable for both methods. Future studies should explore the potential for fewer complications with the robotic-assisted approach as suggested by the lower point estimate.

Photophysical Properties of (E)-1-(4-(Diethyla-mino)-2-hydroxybenzylidene)-4,4-dimethylthiosemicarbazide Compound and Its Triple Fluorescence Emission Mechanism: A Theoretical Perspective.

In view of the application prospects in biomedicine of (E)-1-(4-(diethyla-mino)-2-hydroxybenzylidene)-4,4-dimethylthiosemicarbazide (DAHTS), the behavior of excited-state dynamics and photophysical properties were studied using the density functional theory/time-dependent density functional theory method. A series of studies indicated that the intramolecular hydrogen-bond (IHB) intensity of DAHTS was enhanced after photoexcitation. This was conducive to promoting the excited-state intramolecular proton-transfer (ESIPT) process. Combining the analysis of the IHB and hole-electron, it revealed that the molecule underwent both the ESIPT process and the twisted charge-transfer (TICT) process. Relying on exploration of the potential energy surface, it was proposed that the different competitive mechanisms between the ESIPT and TICT processes were regulated by solvent polarity. In acetonitrile (ACN) solvent, the ESIPT process occurred first, and the TICT process occurred later. In contrast, in the CYH solvent, the molecule first underwent the TICT process and then the ESIPT process. Furthermore, we raised the possibility that the TICT behavior was the cause of weak fluorescence emission for the DAHTS in CYH and ACN solvents. By the dimer correlation analysis, the corresponding components of triple fluorescence emission were clearly assigned, corresponding to the monomer, dimer, and ESIPT isomer in turn. Our work precisely elucidated the photophysical mechanism of DAHTS and the attribution of the triple fluorescence emission components, which provided valuable guidance for the development and regulation of bioactive fluorescence probes with multiband and multicolor emission characteristics.

Bacillus velezensis A2 Can Protect against Damage to IPEC-J2 Cells Induced by Zearalenone via the Wnt/FRZB/ß-Catenin Signaling Pathway.

Zearalenone (ZEA) has adverse effects on human and animal health, and finding effective strategies to combat its toxicity is essential. The probiotic Bacillus velezensis A2 shows various beneficial physiological functions, including the potential to combat fungal toxins. However, the detailed mechanism by which the Bacillus velezensis A2 strain achieves this protective effect is not yet fully revealed. This experiment was based on transcriptome data to study the protective mechanism of Bacillus velezensis A2 against ZEA-induced damage to IPEC-J2 cells. The experiment was divided into CON, A2, ZEA, and A2+ZEA groups. This research used an oxidation kit to measure oxidative damage indicators, the terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) method to detect cell apoptosis, flow cytometry to determine the cell cycle, and transcriptome sequencing to screen and identify differentially expressed genes. In addition, gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) were adopted to screen out relevant signaling pathways. Finally, to determine whether A2 can alleviate the damage caused by ZEA to cells, the genes and proteins involved in inflammation, cell apoptosis, cell cycles, and related pathways were validated using a quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot methods. Compared with the CON group, the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) in the ZEA group increased significantly (p < 0.01), while the levels of antioxidant enzyme activity, total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-PX), total antioxidant capacity (T-AOC), and catalase (CAT) decreased significantly (p < 0.01). Compared with the ZEA group, the A2+ZEA group showed a significant decrease in ROS and MDA levels (p < 0.01), while the levels of T-SOD, GSH-PX, T-AOC, and CAT increased significantly (p < 0.01). TUNEL and cell cycle results indicated that compared with the ZEA group, the A2+ZEA group demonstrated a significant decrease in the cell apoptosis rate (p < 0.01), and the cell cycle was restored. Combining transcriptome data, qRT-PCR, and Western blot, the results showed that compared with the CON group, the mRNA and protein expression levels of Wnt10 and ß-catenin increased significantly (p < 0.01), while the expression level of FRZB decreased significantly (p < 0.01); compared with the ZEA group, the expression levels of these mRNA and proteins were reversed. Bacillus velezensis A2 can increase the antioxidant level, reduce inflammatory damage, decrease cell apoptosis, and correct the cell cycle when that damage is being caused by ZEA. The protective mechanism may be related to the regulation of the Wnt/FRZB cell/ß-catenin signaling pathway.

Nanoflower-Like High-Entropy Co-Fe-Cr-Mo-Mn Spinel for Oxygen Evolution.

Oxygen evolution reaction (OER) is the key anode reaction of electrolytic water. To improve the slow OER kinetics, we synthesize nanoflower-like Co-Fe-Cr-Mo-Mn high-entropy spinel (HES) nanosheets on nickel foam (NF) by one-step solvothermal method, which exhibit an overpotential (η10) of only 188 mV at 10 mA cm-2, much lower than bimetallic CoFeOx/NF (233 mV), trimetallic CoFeCrOx/NF (211 mV), and tetrametallic CoFeCrMoOx/NF (200 mV). The OER overpotential decreases with the increase of the number of metals, indicating that the formation of HES has a positive effect on the improvement of electrocatalytic performance, since the synergistic effect between different metals enhances the charge transfer rate and decreases reaction barrier. In-situ Raman spectra demonstrate that the formation of γ-NiOOH on the HES surface is a crucial active species for the OER. This work demonstrates a simple and efficient synthesis method to prepare nanoflower-like high-entropy electrocatalysts for efficient OER electrocatalysis.

Coarse-to-fine registration and time-intensity curves constraint for liver DCE-MRI synthesis.

Image registration plays a crucial role in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), used as a fundamental step for the subsequent diagnosis of benign and malignant tumors. However, the registration process encounters significant challenges due to the substantial intensity changes observed among different time points, resulting from the injection of contrast agents. Furthermore, previous studies have often overlooked the alignment of small structures, such as tumors and vessels. In this work, we propose a novel DCE-MRI registration framework that can effectively align the DCE-MRI time series. Specifically, our DCE-MRI registration framework consists of two steps, i.e., a de-enhancement synthesis step and a coarse-to-fine registration step. In the de-enhancement synthesis step, a disentanglement network separates DCE-MRI images into a content component representing the anatomical structures and a style component indicating the presence or absence of contrast agents. This step generates synthetic images where the contrast agents are removed from the original images, alleviating the negative effects of intensity changes on the subsequent registration process. In the registration step, we utilize a coarse registration network followed by a refined registration network. These two networks facilitate the estimation of both the coarse and refined displacement vector fields (DVFs) in a pairwise and groupwise registration manner, respectively. In addition, to enhance the alignment accuracy for small structures, a voxel-wise constraint is further conducted by assessing the smoothness of the time-intensity curves (TICs). Experimental results on liver DCE-MRI demonstrate that our proposed method outperforms state-of-the-art approaches, offering more robust and accurate alignment results.

Self-supervised neural network-based endoscopic monocular 3D reconstruction method.

Based on deep learning, monocular visual 3D reconstruction methods have been applied in various conventional fields. In the aspect of medical endoscopic imaging, due to the difficulty in obtaining real information, self-supervised deep learning has always been a focus of research. However, current research on endoscopic 3D reconstruction is mainly conducted in laboratory environments, lacking experience in dealing with complex clinical surgical environments. In this work, we use an optical flow-based neural network to address the problem of inconsistent brightness between frames. Additionally, attention modules and inter-layer losses are introduced to tackle the complexity of endoscopic scenes in clinical surgeries. The attention mechanism allows the network to better focus on pixel texture details and depth differences, while the inter-layer losses supervise the network at different scales. We have established a complete monocular endoscopic 3D reconstruction framework and conducted quantitative experiments on a clinical dataset using the cross-correlation coefficient as a metric. Compared with other self-supervised methods, our framework can better simulate the mapping relationship between adjacent frames during endoscope motion. To validate the generalization performance of our framework, we tested the model trained on the clinical dataset on the SCARED dataset and achieved equally excellent results.

In situ synthesis of rosette-like Co-doped FeNiOOH/NF for seawater oxidation.

The development of high activity and strong resistance to seawater corrosion oxygen evolution reaction (OER) electrocatalysts for seawater electrolysis has broad application prospects. Herein, we prepare Co-doped FeNiOOH rosette-like nanoflowers on nickel foam (NF) with different Co dosages by one-step solvothermal method. The Co0.2-FeNiOOH/NF exhibits a low overpotential (η10) of 185 mV and Tafel slope of 30 mV dec-1 in 1 M KOH. Moreover, it shows a low η10 of 244 mV in alkaline seawater electrolyte. The remarkable OER performance of Co0.2-FeNiOOH/NF is ascribed to the fact that the introduction of Co regulates the morphology and electron structure of the material, which provides abundant active sites for the reaction and promotes charge transfer. In situ Raman results demonstrate that NiOOH and γ-FeOOH are the key active species for the OER. This study provides a feasible basis for seawater electrolysis over transition metal (oxy)hydroxides.

Nanoflower-like high-entropy Ni-Fe-Cr-Mn-Co (oxy)hydroxides for oxygen evolution.

High-entropy materials (HEMs) have potential application value in electrocatalytic water splitting because of their unique alloy design concept and significant mixed entropy effect. Here, we synthesize a high-entropy Ni-Fe-Cr-Mn-Co (oxy)hydroxide on nickel foam (NF) by a solvothermal method. The flower-like structure of FeNiCrMnCoOOH/NF can provide abundant active sites, thus improving the oxygen evolution reaction (OER) activity. In 1 M KOH, the FeNiCrMnCoOOH/NF shows an ultra-low overpotential (η10) of 201 mV for the OER, superior to FeNiCrMnAlOOH/NF, FeNiCrMnCuOOH/NF, FeNiCrMnMoOOH/NF, and FeNiCrMnCeOOH/NF. In addition, it exhibits a low η10 of 223 mV in 0.5 M NaCl + 1 M KOH and excellent stability. Electrochemical impedance spectroscopy measurements indicate that the synergistic effect between multiple metals accelerates charge transfer, while in situ Raman measurements reveal that NiOOH is a key active species for the OER. This work is of great significance for the construction of high-entropy (oxy)hydroxides for seawater electrolysis.

Research advances of SERS analysis method based on silent region molecules for food safety detection.

Food safety is a critical issue that is closely related to people's health and safety. As a simple, rapid, and sensitive detection technique, surface-enhanced Raman scattering (SERS) technology has significant potential for food safety detection. Recently, researchers have shown a growing interest in utilizing silent region molecules for SERS analysis. These molecules exhibit significant Raman scattering peaks in the cellular Raman silent region between 1800 and 2800 cm-1 avoiding overlapping with the SERS spectrum of biological matrices in the range 600-1800 cm-1, which could effectively circumvent matrix effects and improve the SERS accuracy. In this review, the application of silent region molecules-based SERS analytical technique for food safety detection is introduced, detection strategies including label-free detection and labeled detection are discussed, and recent applications of SERS analysis technology based on molecules containing alkyne and nitrile groups, as well as Prussian blue (PB) in the detection of pesticides, mycotoxins, metal ions, and foodborne pathogens are highlighted. This review aims to draw the attention to the silent region molecules-based SERS analytical technique and to provide theoretical support for its further applications in food safety detection.

Microbial Colonization of Capsular Traction Sutures in Hip Arthroscopic Surgery.

Background: A common practice in hip arthroscopic surgery is the utilization of capsular traction sutures that can be incorporated into the capsular repair site at the end of the procedure, potentially seeding the hip joint with colonized suture material. Purpose: To investigate the rate of the microbial colonization of capsular traction sutures used during hip arthroscopic surgery and to identify patient-associated risk factors for this microbial colonization. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 50 consecutive patients who underwent hip arthroscopic surgery with a single surgeon were enrolled. There were 4 braided nonabsorbable sutures utilized for capsular traction during each hip arthroscopic procedure. These 4 traction sutures and 1 control suture were submitted for aerobic and nonaerobic cultures. Cultures were held for 21 days. Demographic information was collected, such as age, sex, and body mass index. All variables underwent bivariate analysis, and variables with a P value <.1 underwent further analysis in a multivariate logistic regression model. Results: One of 200 experimental traction sutures and 1 of 50 control sutures had a positive culture. Proteus mirabilis and Citrobacter koseri were isolated in both these positive experimental and control cultures from the same patient. Age and traction time were not significantly associated with positive cultures. The rate of microbial colonization was 0.5%. Conclusion: The rate of the microbial colonization of capsular traction sutures used in hip arthroscopic surgery was low, and no patient-associated risk factors were identified for microbial colonization. Capsular traction sutures used in hip arthroscopic surgery were not a significant potential source of microbial contamination. Based on these results, capsular traction sutures can be incorporated in capsular closure with a low risk of seeding the hip joint with microbial contaminants.

Effect of Metal Complexing on Mn-Fe/TS-1 Catalysts for Selective Catalytic Reduction of NO with NH3.

TS-1 zeolite with desirable pore structure, an abundance of acidic sites, and good thermal stability promising as a support for the selective catalytic reduction of NO with NH3 (NH3-SCR). Herein, a series of Mn-Fe/TS-1 catalysts have been synthesized, adopting tetraethylenepentamine (TEPA) as a metal complexing agent using the one-pot hydrothermal method. The introduced TEPA can not only increase the loading of active components but also prompts the formation of a hierarchical structure through decreasing the size of TS-1 nanocrystals to produce intercrystalline mesopores during the hydrothermal crystallization process. The optimized Mn-Fe/TS-1(R-2) catalyst shows remarkable NH3-SCR performance. Moreover, it exhibits excellent resistance to H2O and SO2 at low temperatures. The characterization results indicate that Mn-Fe/TS-1(R-2) possesses abundant surface Mn4+ and Fe2+ and chemisorbed oxygen, strong reducibility, and a high Brønsted acid amount. For comparison, Mn-Fe/TiO2 displays a narrower active temperature window due to its poor thermostability.

Screening for urinary markers predicting hematopoietic stem cell injury induced by busulfan using genetically diverse mice.

BACKGROUND: Busulfan (BU) is an alkylating agent used as a conditioning agent prior to hematopoietic stem cell (HSC) transplantation as it is known to be cytotoxic to host hematopoietic stem and progenitor cells. The susceptibility of HSCs to BU injury plays an important role in the myeloablative efficacy of BU. Different susceptibilities were demonstrated in genetically diverse (GD) mice in our preliminary research. METHODS: Three strains of GD mice with different susceptibilities to BU-induced HSC injury were used for screening biological markers of HSC injury susceptibility in urine. The urine proteins were analyzed using liquid chromatography coupled with tandem mass spectrometry to screen for differentially expressed proteins. Screening for possible biomarkers based on differences in protein expression abundance was validated using enzyme-linked immunoassay (ELISA). RESULTS: Functional analysis showed that the differential proteins were all involved in a series of biological pathways related to cellular senescence, apoptosis, and angiogenesis; whereas the differential proteins of the high-susceptible strain were enriched for the regulation of bone marrow microenvironment pathways, those of low-susceptible strain were enriched for the proapoptotic effect of GTPase pathways. Based on protein abundance differences, several urinary proteins that may be indicative of susceptibility were screened, and ELISA validation results showed that angiotensin-converting enzyme may be a potential biomarker predicting HSC susceptibility for BU conditioning. CONCLUSIONS: This study indicates that urinary protein levels can reflect differences in susceptibility to BU-induced HSC injury. Using GD mice to construct genetic difference models will provide preclinical data for screening BU-related biological markers.

Asymmetric Cross Metasurfaces with Multiple Resonances Governed by Bound States in the Continuum.

The bound state in the continuum (BIC) has paved a new way to achieve excellent localization of the resonant mode coexisting with a continuous spectrum in the metasurface. Here, we propose an all-dielectric metasurface consisting of periodic pairs of asymmetric crosses that supports multiple Fano resonances. Due to the sufficient degrees of freedom in the unit cell, we displaced the vertical bars horizontally to introduce in-plane perturbation, doubling the unit cell structure. Dimerization directly resulted in the folding of the Brillouin zone in k space and transformed the BIC modes into quasi-BIC resonances. Then, simultaneous in-plane symmetry breaking was introduced in both the x and y directions to excite two more resonances. The physical mechanisms of these BIC modes were investigated by multipole decomposition of the scattering cross section and electromagnetic near-field analysis, confirming that they are governed by toroidal dipole (TD) modes and magnetic dipole (MD) modes. We also investigated the flexible tunability and evaluated the sensing performance of our proposed metasurface. Our work is promising for different applications requiring stable and tunable resonances, such as optical switching and biomolecule sensing.

Effects of midgut bacteria in Hyphantria cunea (Lepidoptera: Erebidae) on nuclear polyhedrosis virus and Bacillus thuringiensis (Bacillales: Bacillaceae).

Hyphantria cunea Drury (Lepidoptera: Erebidae) is a quarantine pest in China that can cause damage to hundreds of plants. As biological control agents, Nuclear Polyhedrosis Virus (NPV) and Bacillus thuringiensis Berliner (Bacillales: Bacillaceae) (Bt) are commonly used to inhibit the prevalence of H. cunea. To investigate the role of midgut bacteria in the infection of NPV and Bt in H. cunea, we performed a series of tests, including isolating the dominant culturable bacteria in the midgut, eliminating intestinal bacteria, and respectively inoculating the dominant strains with NPV and Bt for bioassay. Two dominant bacteria, Klebsiella oxytoca Lautrop (Enterobacterales: Enterobacteriaceae) and Enterococcus mundtii Collins (Lactobacillales: Enterococcaceae), in the midgut of H. cunea were identified, and a strain of H. cunea larvae without intestinal bacteria was successfully established. In the bioassays of entomopathogen infection, K. oxytoca showed significant synergistic effects with both NPV and Bt on the death of H. cunea. In contrast, E. mundtii played antagonistic effects. This phenomenon may be attributed to the differences in the physico-chemical properties of the two gut bacteria and the alkaline environment required for NPV and Bt to infect the host. It is worth noting that the enhanced insecticidal activity of K. oxytoca on NPV and Bt provides a reference for future biological control of H. cunea by intestinal bacteria.

Immunotoxicity of Three Environmental Mycotoxins and Their Risks of Increasing Pathogen Infections.

Aflatoxin B1 (AFB1), ochratoxin A (OTA), and deoxynivalenol (DON) are the three mycotoxins that have received the most scholarly attention and have been tested most routinely in clinics. These mycotoxins not only suppress immune responses but also induce inflammation and even increase susceptibility to pathogens. Here, we comprehensively reviewed the determining factors for the bidirectional immunotoxicity of the three mycotoxins, their effects on pathogens, and their action mechanisms. The determining factors include mycotoxin exposure doses and times, as well as species, sex, and some immunologic stimulants. Moreover, mycotoxin exposure can affect the infection severity of some pathogens, including bacteria, viruses, and parasites. Their specific action mechanisms include three aspects: (1) mycotoxin exposure directly promotes the proliferation of pathogenic microorganisms; (2) mycotoxins produce toxicity, destroy the integrity of the mucosal barrier, and promote inflammatory response, thereby improving the susceptibility of the host; (3) mycotoxins reduce the activity of some specific immune cells and induce immune suppression, resulting in reduced host resistance. The present review will provide a scientific basis for the control of these three mycotoxins and also provide a reference for research on the causes of increased subclinical infections.

Effect of spermidine on radiation-induced long-term bone marrow cell injury.

OBJECTIVE: Spermidine, a natural polyamine, possesses anti-oxidant, autophagy-regulation, and anti-aging properties. Elevated levels of oxidative stress, which was mediated the senescence of hematopoietic stem cells (HSCs) induced by radiation exposure, may further contribute to long-term myelosuppression. Therefore, this study investigated the protective effect of spermidine on the long-term damage of the hematopoietic system caused by radiation exposure. METHODS: In vitro experiments, bone marrow mononuclear cells (BMMNCs) of C57BL/6 mice were isolated and incubated with 5 mM spermidine for 30 min, then irradiated by 2 Gy X ray. The survival rate, proliferation, and differentiation ability of BMMNCs were detected. In vivo experiment, mice received 4 Gy total body irradiation (TBI), 3 mM spermidine were administered in the drinking water every day for 14 days prior to irradiation and then continued for 30 days after irradiation. Peripheral blood, bone marrow cell typing, level of reactive oxygen species (ROS), colony-forming ability of HSC, and transplantation-reconstitution capability were detected. RESULTS: In vitro experiments, spermidine significantly improved the survival rate of BMMNCs as well as the proliferation and differentiation ability of HSCs exposure to ionizing radiation (IR). In vivo, spermidine reduced levels of ROS in HSCs; spermidine attenuated long-term myeloid differentiation deviation induced by TBI. Spermidine promoted the proliferation and differentiation ability of stem cells, but failed to ameliorate the decreased engraftment capacity of bone marrow cells in mice exposed to TBI. CONCLUSION: This study demonstrated that spermidine could promote the recovery of IR-induced inhibition of proliferation and differentiation ability of HSCs, partly through antioxidant effects. Whether combining spermidine with other radioprotectants could further increase protective efficacy and reduce the long-term bone marrow injury needs further investigation.

Alveolar Macrophages Participate in the Promotion of Influenza Virus Infection by Aflatoxin B1 at an Early Stage.

Aflatoxin B1 (AFB1), one of the most common environmental mycotoxin contaminations in food and feed, poses significant threats to human and animal health. Our previous study indicated that even non-toxic AFB1 concentrations could promote influenza virus replication and induce influenza virus-infected alveolar macrophages polarizing from M1 (immunostimulatory phenotype) to M2 (immunosuppressive phenotype) over time. However, whether AFB1 promotes influenza replication via modulating the polarization of alveolar macrophages is unknown. Here, we specifically depleted alveolar macrophages using clodronate-containing liposomes in swine influenza virus (SIV)-infected mice to explore the mechanism the promotion of SIV replication by AFB1. The results show that the depletion of alveolar macrophages significantly alleviated the AFB1-induced weight loss, inflammatory responses, and lung and immune organ damage of the SIV-infected mice after 14 days and greatly diminished the AFB1-promoted SIV replication. In contrast, the depletion of alveolar macrophages did not alleviate the AFB1-induced weight loss, and lung and immune organ damage of the SIV-infected mice after 28 days and slightly diminished the AFB1-promoted SIV replication. Collectively, the data indicate that alveolar macrophages play a crucial role the promotion of SIV infection by AFB1 in the early rather than late stage, and AFB1 can promote SIV replication by inducing alveolar macrophages to polarize towards M1 macrophages. This research provides novel targets for reducing the risk of AFB1-promoted influenza virus infection.

Safety evaluation method in multi-logical scenarios for automated vehicles based on naturalistic driving trajectory.

Automated driving technology has constantly been maturing; however, how to ensure automated vehicle (AV) safety has not yet been effectively solved, functional safety assessment remains an important part of the development of automated driving technology. To compensate for the lack of multidimensional evaluation indicators, this paper proposes a safety evaluation method in multi-logical scenarios (SEMMS) for AVs' functional safety based on naturalistic driving trajectory (NDT) in order to evaluate the comprehensive performance of the tested AV in a diversity of scenarios simultaneously. The potential field method is used to describe the quantified danger level of an AV in a single concrete scenario that considers the dangerous situation of the scenario and AV test results. Combined with the internal probability distribution of the logical scenario parameter space obtained by NDT, the safety performance of an AV in logical scenario is calculated by integrating the two indexes. With the information entropy and relative frequency of different logical scenarios, the relative weights of logical scenarios are obtained, and the safety performance evaluation results of the tested AV in the multi-logical scenarios can be determined based on the weighting danger level in different logical scenarios. During the actual application of the method, the HighD database was used as the input source of NDT, and a black-box automated driving algorithm was subjected to traversal tests in three logical scenarios. The test results of the automated driving algorithm were evaluated using the SEMMS, and the results show that the SEMMS could well evaluate the performance of the tested automated driving algorithm in multiple kinds of logical scenarios simultaneously, indicating that it is an effective solution to the problem of automated driving algorithm safety evaluation.