Simple and scalable preparation of lignin based porous carbon coated nano-clay composites and their efficient removal for the diversified iodine

Here, lignin and nano-clay were used to prepare novel composite adsorbents by one-step carbonization without adding activators for radioactive iodine capture. Specially, 1D nano-clay such as halloysite (Hal), palygorskite (Pal) and sepiolite (Sep) were selected as skeleton components, respectively, enzymatic hydrolysis lignin (EHL) as carbon source, lignin based porous carbon/nano-clay composites (ELC-X) were prepared through ultrasonic impregnation, freeze drying, and carbonization. Characterization results indicated lignin based porous carbon (ELC) well coated on the surface of nano-clay, and made its surface areas increase to 252 m2/g. These composites appeared the micro-mesoporous hierarchical structure, considerable N doping and good chemical stability. Results of adsorption experiments showed that the introduction of ELC could well promote iodine vapor uptake of nano-clay, and up to 435.0 mg/g. Meanwhile, the synergistic effect between lignin based carbon and nano-clay was very significant for the adsorption of iodine/n-hexane and iodine ions, their capacity were far exceed those of a single material, respectively. The relevant adsorption kinetic and thermodynamics, and mechanism of ELC-X composites were clarified. This work provided a class of low-cost and environmentally friendly adsorbents for radioactive iodine capture, and opened up ideas for the comprehensive utilization of waste lignin and natural clay minerals.

Three-dimensional pseudo-continuous arterial spin-labelled perfusion imaging for diagnosing upper cervical lymph node metastasis in patients with nasopharyngeal carcinoma: a whole-node histogram analysis

AIM

To evaluate whole-node histogram parameters of blood flow (BF) maps derived from three-dimensional pseudo-continuous arterial spin-labelled (3D pCASL) imaging in discriminating metastatic from benign upper cervical lymph nodes (UCLNs) for nasopharyngeal carcinoma (NPC) patients.

MATERIALS AND METHODS

Eighty NPC patients with a total of 170 histologically confirmed UCLNs (67 benign and 103 metastatic) were included retrospectively. Pre-treatment 3D pCASL imaging was performed and whole-node histogram analysis was then applied. Histogram parameters and morphological features, such as minimum axis diameter (MinAD), maximum axis diameter (MaxAD), and location of UCLNs, were assessed and compared between benign and metastatic lesions. Predictors were identified and further applied to establish a combined model by multivariate logistic regression in predicting the probability of metastatic UCLNs. Receiver operating characteristic (ROC) curves were used to analyse the diagnostic performance.

RESULTS

Metastatic UCLNs had larger MinAD and MinAD/MaxAD ratio, greater energy and entropy values, and higher incidence of level II (upper jugular group), but lower BF10th value than benign nodes (all p<0.05). MinAD, BF10th, energy, and entropy were validated as independent predictors in diagnosing metastatic UCLNs. The combined model yielded an area under the curve (AUC) of 0.932, accuracy of 84.42 %, sensitivity of 80.6 %, and specificity of 90.29 %.

CONCLUSIONS

Whole-node histogram analysis on BF maps is a feasible tool to differentiate metastatic from benign UCLNs in NPC patients, and the combined model can further improve the diagnostic efficacy.

Measurements of All-Particle Energy Spectrum and Mean Logarithmic Mass of Cosmic Rays from 0.3 to 30 PeV with LHAASO-KM2A

We present the measurements of all-particle energy spectrum and mean logarithmic mass of cosmic rays in the energy range of 0.3-30 PeV using data collected from LHAASO-KM2A between September 2021 and December 2022, which is based on a nearly composition-independent energy reconstruction method, achieving unprecedented accuracy. Our analysis reveals the position of the knee at 3.67±0.05±0.15  PeV. Below the knee, the spectral index is found to be -2.7413±0.0004±0.0050, while above the knee, it is -3.128±0.005±0.027, with the sharpness of the transition measured with a statistical error of 2%. The mean logarithmic mass of cosmic rays is almost heavier than helium in the whole measured energy range. It decreases from 1.7 at 0.3 PeV to 1.3 at 3 PeV, representing a 24% decline following a power law with an index of -0.1200±0.0003±0.0341. This is equivalent to an increase in abundance of light components. Above the knee, the mean logarithmic mass exhibits a power law trend towards heavier components, which is reversal to the behavior observed in the all-particle energy spectrum. Additionally, the knee position and the change in power-law index are approximately the same. These findings suggest that the knee observed in the all-particle spectrum corresponds to the knee of the light component, rather than the medium-heavy components.

[Preliminary study on automatic quantification and grading of leopard spots fundus based on deep learning technology]

Objective: To achieve automatic segmentation, quantification, and grading of different regions of leopard spots fundus (FT) using deep learning technology. The analysis includes exploring the correlation between novel quantitative indicators, leopard spot fundus grades, and various systemic and ocular parameters. Methods: This was a cross-sectional study. The data were sourced from the Beijing Eye Study, a population-based longitudinal study. In 2001, a group of individuals aged 40 and above were surveyed in five urban communities in Haidian District and three rural communities in Daxing District of Beijing. A follow-up was conducted in 2011. This study included individuals aged 50 and above who participated in the second 5-year follow-up in 2011, considering only the data from the right eye. Color fundus images centered on the macula of the right eye were input into the leopard spot segmentation model and macular detection network. Using the macular center as the origin, with inner circle diameters of 1 mm, 3 mm, and outer circle diameter of 6 mm, fine segmentation of the fundus was achieved. This allowed the calculation of the leopard spot density (FTD) and leopard spot grade for each region. Further analyses of the differences in ocular and systemic parameters among different regions' FTD and leopard spot grades were conducted. The participants were categorized into three refractive types based on equivalent spherical power (SE): myopia (SE<-0.25 D), emmetropia (-0.25 D≤SE≤0.25 D), and hyperopia (SE>0.25 D). Based on axial length, the participants were divided into groups with axial length<24 mm, 24-26 mm, and>26 mm for the analysis of different types of FTD. Statistical analyses were performed using one-way analysis of variance, Kruskal-Wallis test, Bonferroni test, and Spearman correlation analysis. Results: The study included 3 369 participants (3 369 eyes) with an average age of (63.9±10.6) years; among them, 1 886 were female (56.0%) and 1, 483 were male (64.0%). The overall FTD for all eyes was 0.060 (0.016, 0.163); inner circle FTD was 0.000 (0.000, 0.025); middle circle FTD was 0.030 (0.000, 0.130); outer circle FTD was 0.055 (0.009, 0.171). The results of the univariate analysis indicated that FTD in various regions was correlated with axial length (overall: r=0.38, P<0.001; inner circle: r=0.31, P<0.001; middle circle: r=0.36, P<0.001; outer circle: r=0.39, P<0.001), subfoveal choroidal thickness (SFCT) (overall: r=-0.69, P<0.001; inner circle: r=-0.57, P<0.001; middle circle: r=-0.68, P<0.001; outer circle: r=-0.72, P<0.001), age (overall: r=0.34, P<0.001; inner circle: r=0.30, P<0.001; middle circle: r=0.31, P<0.001; outer circle: r=0.35, P<0.001), gender (overall: r=-0.11, P<0.001; inner circle: r=-0.04, P<0.001; middle circle: r=-0.07, P<0.001; outer circle: r=-0.11, P<0.001), SE (overall: r=-0.20; P<0.001; inner circle: r=-0.19, P<0.001; middle circle: r=-0.20, P<0.001; outer circle: r=-0.20, P<0.001), uncorrected visual acuity (overall: r=-0.18, P<0.001; inner circle: r=-0.26, P<0.001; middle circle: r=-0.24, P<0.001; outer circle: r=-0.22, P<0.001), and body mass index (BMI) (overall: r=-0.11, P<0.001; inner circle: r=-0.13, P<0.001; middle circle: r=-0.14, P<0.001; outer circle: r=-0.13, P<0.001). Further multivariate analysis results indicated that different region FTD was correlated with axial length (overall: β=0.020, P<0.001; inner circle: β=-0.022, P<0.001; middle circle: β=0.027, P<0.001; outer circle: β=0.022, P<0.001), SFCT (overall: β=-0.001, P<0.001; inner circle: β=-0.001, P<0.001; middle circle: β=-0.001, P<0.001; outer circle: β=-0.001, P<0.001), and age (overall: β=0.002, P<0.001; inner circle: β=0.001, P<0.001; middle circle: β=0.002, P<0.001; outer circle: β=0.002, P<0.001). The distribution of overall (H=56.76, P<0.001), inner circle (H=72.22, P<0.001), middle circle (H=75.83, P<0.001), and outer circle (H=70.34, P<0.001) FTD differed significantly among different refractive types. The distribution of overall (H=373.15, P<0.001), inner circle (H=367.67, P<0.001), middle circle (H=389.14, P<0.001), and outer circle (H=386.89, P<0.001) FTD differed significantly among different axial length groups. Furthermore, comparing various levels of FTD with systemic and ocular parameters, significant differences were found in axial length (F=142.85, P<0.001) and SFCT (F=530.46, P<0.001). Conclusions: The use of deep learning technology enables automatic segmentation and quantification of different regions of theFT, as well as preliminary grading. Different region FTD is significantly correlated with axial length, SFCT, and age. Individuals with older age, myopia, and longer axial length tend to have higher FTD and more advanced FT grades.

[Emphasizing the timing and procedure selection for vitrectomy in pathological myopic traction maculopathy]

Myopic maculopathy is the primary cause of irreversible visual impairment in patients with pathologic myopia, and myopic traction maculopathy often requires vitrectomy for treatment. Myopic traction maculopathy encompasses epiretinal membrane, foveoschisis, macular hole, and macular hole-related retinal detachment. It is recommended to perform vitrectomy combined with inner limiting membrane peeling for Type II epiretinal membrane, foveal-sparing inner limiting membrane peeling for foveoschisis, inverted inner limiting membrane flap technique for macular hole, and vitrectomy combined with macular buckle for refractory macular hole-related retinal detachment. Myopic traction maculopathy is a chronically progressive condition, and surgeons need to accurately determine the timing of surgery and choose appropriate procedures to maximize the benefits for patients.

Encapsulated lignin-based slow-release manganese fertilizer with reduced cadmium accumulation in rice (Oryza sativa L.)

As an essential trace element for plant growth and development, manganese plays a crucial role in the uptake of the heavy metal cadmium by rice (Oryza sativa L.). In this study, we developed a novel slow-release manganese fertilizer named Mn@LNS-EL. Initially, lignin nanoparticles were derived from sodium lignosulfonate, and a one-step emulsification strategy was employed to prepare a water-in-oil-in-water (W/O/W) Pickering double emulsions. These double emulsions served as the template for interfacial polymerization of lignin nanoparticles and epichlorohydrin, resulting in the formation of microcapsule wall materials. Subsequently, manganese fertilizer (MnSO4) was successfully encapsulated within the microcapsules. Hydroponic experiments were conducted to investigate the effects of Mn@LNS-EL on rice growth and the cadmium and manganese contents in the roots and shoots of rice under cadmium stress conditions. The results revealed that the treatment with Mn@LNS-EL markedly alleviated the inhibitory effects of cadmium on rice growth, leading to notably lower cadmium levels in the rice roots and shoots compared to the specimens treated without manganese fertilizer. Specifically, there was a reduction of 37.9 % in the root cadmium content and a 17.1 % decrease in the shoot cadmium content. In conclusion, this study presents an innovative approach for the high-value utilization of lignin through effective encapsulation and slow-release mechanisms of trace-element fertilizers while offering a promising strategy for efficiently remediating cadmium pollution in rice.

Measurement of Ultra-High-Energy Diffuse Gamma-Ray Emission of the Galactic Plane from 10 TeV to 1 PeV with LHAASO-KM2A

The diffuse Galactic γ-ray emission, mainly produced via interactions between cosmic rays and the interstellar medium and/or radiation field, is a very important probe of the distribution, propagation, and interaction of cosmic rays in the Milky Way. In this Letter, we report the measurements of diffuse γ rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO). Diffuse emissions from the inner (15°10  TeV). The energy spectrum in the inner Galaxy regions can be described by a power-law function with an index of -2.99±0.04, which is different from the curved spectrum as expected from hadronic interactions between locally measured cosmic rays and the line-of-sight integrated gas content. Furthermore, the measured flux is higher by a factor of ∼3 than the prediction. A similar spectrum with an index of -2.99±0.07 is found in the outer Galaxy region, and the absolute flux for 10≲E≲60  TeV is again higher than the prediction for hadronic cosmic ray interactions. The latitude distributions of the diffuse emission are consistent with the gas distribution, while the longitude distributions show clear deviation from the gas distribution. The LHAASO measurements imply that either additional emission sources exist or cosmic ray intensities have spatial variations.

Evaluation of Treatment Interruptions and Recovery during Biology-Guided Radiotherapy Delivery

PURPOSE/OBJECTIVE(S)

A Biology-guided Radiotherapy (BgRT) based device is designed to use Positron Emission Tomography (PET) signals to achieve tracked dose delivery. The goal of this study is to investigate the dose delivery accuracy in case of interruption during BgRT treatment, and resumption in a separate treatment session for a multi-target delivery, as the PET activity continues to decay.

MATERIALS/METHODS

A custom-built large anthropomorphic phantom (LAP) including a 26 mm spherical target with 3D independent motion and two 22 mm spherical targets with 1D sinusoidal motion embedded in water was used. All three targets were filled with FGD in an 8:1 target to background uptake ratio (41.52 kBq/ml in target and 5.19 kBq/ml in background). During BgRT delivery, the treatment was intentionally paused during delivery to the second target and the current treatment session was ended to generate a partial fraction. Then the partial fraction was continued in a new session, where the CT scan localization and PET pre-scan were repeated using the existing PET activity present in the phantom. The newly acquired PET pre-scan, was then used to determine if sufficient PET counts were present to resume treatment delivery. The interruption and recovery algorithm is designed to calculate the fluence that needs to be delivered to the remaining targets as well as the residual fluence to be given to the targets that have already received partial dose prior to the interruption. Once the new fluence is recomputed, the treatment is resumed. The delivered doses were captured using radiochromic film (EBT-XD) inserted in the target as well as post-treatment dose calculations based on the delivered beamlet sequence to evaluate the results in terms of dosimetric coverage and margin loss. The margin loss is calculated as the maximum difference between the distance from the Clinical Target Volume (CTV) contour to the 97% isodose contour in the treatment plan and the on the film. The dosimetric coverage is defined as the percentage of voxels within the CTV that lies within 97% and 130% of the prescribed dose.

RESULTS

As shown in the table below, a margin loss of less than 3 mm for all targets and 100% CTV coverage was achieved. After treatment interruptions, the PET safety evaluation based on the PET pre-scan helped to determine whether the treatment could be continued on the same day using the same injected PET activity (an NTS value ≧ 2 and AC value ≧ 5 kBq/ml).

CONCLUSION

This study demonstrated that the BgRT system is able to deliver the prescribed dose to all targets with independent motion, even when an interruption and resumption occurs during treatment. In case such an interruption if the remaining PET activity satisfies the BgRT safety evaluation, the treatment can continue to deliver the remainder of the BgRT doses.

Intrafraction Dosimetric Evaluation of Biology-Guided Radiotherapy to a Target Under Respiratory Motion

PURPOSE/OBJECTIVE(S)

To evaluate the reproducibility and variability of biology-guided radiotherapy (BgRT) treatments using a large anthropomorphic phantom modeling the motion amplitude of a lung tumor.

MATERIALS/METHODS

RefleXion X1 is equipped with two opposing 90 degrees PET detector arcs to capture the radionuclide emissions and direct the 6MV Linac to treat the lesions in real time. A custom-built phantom filled with a liquid [¹⁸F]Fluorodeoxyglucose (FDG) solution was used. Fillable target and OAR structures were 3D printed and attached to motion stages. The GTV = CTV was matched to the spherical 22 mm diameter target, and the PTV was a 5 mm expansion from the CTV volume. The Biology Tracking Zone (BTZ) was generated after adding 5 mm margin to the motion extent of the CTV. The OAR was a large C-shape annulus (emulating a heart) that was approximately 3 cm from the target. The 3D independent motion trajectory of the target was designed to mimic lung motion: range of +5.8 mm to -4.9 mm in LR, range of +14.4 mm to -11.3 mm in SI, and range of +5.2 mm to -5.1 mm in AP directions. The OAR motion waveform used a 1D sinusoidal pattern with a 5 mm amplitude in SI direction. The target and the OAR were filled with 40 kBq/mL while the background had 5 kBq/mL FDG. A BgRT Modeling (imaging-only) PET acquisition was performed using RefleXion X1 and used to generate a 4-fraction BgRT treatment plan prescribing 10 Gy/fraction to PTV. For each delivery, target, OAR and background were filled with the same FDG concentrations as in the BgRT Modeling PET planning scan. Dosimetry to the target and OAR were both measured using an ion-chamber (Exradin A14SL) and film in the coronal plane through the center of the GTV for all 4 fractions.

RESULTS

The mean activity concentration within the (BTZ) was 7.4 ± 0.8 kBq/mL. The calculated signal-to-noise ratio metric (Normalized Target Signal) within the BTZ was 4.0 ± 0.3. Total treatment times were all less than 35 minutes (34.3 ± 0.2). Prescription dose coverage to the CTV for all 4 fractions was 100%. Ion chamber measurements in the CTV were -1.6 ± 1.3% relative to the planned dose over the active area of the ion-chamber. Minimum and maximum doses to the CTV, measured on film, were -7.7 ± 2.2% and 1.3 ± 1.4%, calculated relative to the planned dose distribution, respectively. The OAR maximum point dose measured on film was -8.7 ± 2.9%, calculated relative to the maximum OAR dose predicted on the bounded dose-volume histogram.

CONCLUSION

Based on this initial study, accurate and reproducible dosimetry can be achieved for targets under respiratory motion using biology-guided radiotherapy over the course of a complete course of treatment. Further studies are needed to evaluate the intrafraction dosimetry of BgRT delivery under various motion models and tumor sizes.

Dosimetric Accuracy of Multi-Target Biology-Guided Radiotherapy Treatments in a Single Session

PURPOSE/OBJECTIVE(S)

We present the first dosimetric measurements of single session, multi-target BgRT deliveries using a clinically realistic motion phantom on a research-only version of the RefleXion X1 system.

MATERIALS/METHODS

A custom-made anthropomorphic phantom of a human torso with embedded fillable targets mimicking 18F-FDG-avid lesions was used. From the three embedded spherical targets, Target 1 was 26 mm in diameter coupled with a 3D independent respiratory motion with 22 mm range, whereas Target 2 and 3 were 22 mm in diameter and moved with a 1D 5 mm maximum sinusoidal motion. The 18F-FDG concentration in the background cavity of the phantom was 5 kBq/ml, and the targets were loaded with 10:1, 8:1 and 6:1 contrast relative to the background for Targets 1, 2, 3, respectively. Spherical structures were contoured as GTVs (CTV = GTV) and a 5 mm margin was added to create PTVs. Motion extent of the tumors were captured to create biological tracking zones for each target. Treatment plans were generated using a research version of the Reflexion treatment planning software to deliver 8 Gy/fx to the PTVs. The treatment delivery was repeated 2 times, and each time the phantom was refilled according to the plan. PET image evaluation metrics for each of the three targets were also recorded. Target dosimetry was measured using a combination of radiographic film and ion chamber. The maximum distance between the 97% prescription isodose line from the plan and the film measurements was used to characterize the dosimetric accuracy of the tracked deliveries. CTV and PTV min, max, and mean doses measured on film were also recorded for each target.

RESULTS

Treatment plans were successfully created with 100% prescription dose coverage to each target loaded with different FDG ratios. Total treatment times for the single-plan, three-target deliveries were less than 80 minutes. PET evaluation metrics at imaging-only and pre-scan, and planning and film dosimetry to the GTV and PTV for each of the three targets is shown in table below (mean ± standard deviation of both deliveries). The CTV dose coverage was maintained for all targets. The shrinkage distance of the 97% prescription dose isodose line on the film plane for all three targets was less than 3 mm for both tests, and ranged from -0.4 to -2.34 mm.

CONCLUSION

These results demonstrate that high tracking accuracy and dosimetric accuracy can be achieved in single session, multi-target deliveries over a range of target-to-background 18F-FDG concentrations and target motion patterns.

Treatment Plan Creation and Delivery with and without BgRT for Static and Motion Trajectories

PURPOSE/OBJECTIVE(S)

In this work we try to validate the motion tracking capabilities of BgRT for periodic and step motion trajectories. SBRT plans that matches the corresponding BgRT plans are created and delivered to the same phantom with and without motion and results are evaluated. Using BgRT based SBRT plans eliminates any user bias and creates SBRT plans that would represent treatment delivery scenarios that could have happened if the PET guided BgRT was not present for that treatment.

MATERIALS/METHODS

To validate SBRT plans that matches the BgRT plans, we used three different types of motion patterns (1) static, (2) lung tumor motion and (3) one-centimeter step-shift. The lung tumor motion (∼25 mm in IEC-Y, ∼7 mm in IEC-X and ∼ 10 mm in IEC-Z) was used as it represents a continuous motion of the target for the entire length of the study while the step-shift case corresponds to the patient or tumor shifting between the localization CT and the start of treatment. First, a 10 Gy per fraction BgRT plan was created for each of the three experiments based on the corresponding PET image. Then, the BgRT plans were delivered to the corresponding targets with and without motion and results are evaluated. To perform a comparative study that assess the performance of BgRT and traditional SBRT (planning and delivery methods), the exact same plan fluence of BgRT plan for each experiment was used to create the corresponding SBRT plans. The newly created SBRT plans were delivered to the corresponding phantom experiments and were compared against BgRT delivery in terms of dose coverage and target margin loss using radiochromic film that moves with the target. The margin loss was calculated as the difference between the distance from the CTV contour to the 97% isodose contour in the treatment plan and the CTV contour to the 97% isodose contour on the film. Dosimetric coverage was on the other hand calculated as the percentage of the voxels within the CTV that lies within 97% and 130% of the prescribed dose.

RESULTS

The results showed that the margin loss for BgRT is less than 3 mm, while for the SBRT plans were more than 3 mm when target motion is present. The dosimetric coverage for BgRT was 100% for all three cases, however less than 100% for the SBRT cases with motion. Table showing margin loss for the various experiments for a prescription dose of 10 Gy.

CONCLUSION

The results shows that BgRT is capable of tracking the tumor motion and delivering the prescribed dose to the moving target.

Characterization of Biology-Guided Radiotherapy Accuracy as a Function of PET Tracer Uptake

PURPOSE/OBJECTIVE(S)

To characterize the tracking capability and dosimetric accuracy of biology-guided radiotherapy (BgRT) under clinically relevant PET tracer uptake scenarios relative to the background.

MATERIALS/METHODS

A custom-made anthropomorphic phantom filled with a liquid 18F-FDG solution including two embedded fillable 22 mm diameter spherical structures mimicking GTV (= CTV) and OAR was coupled to motion stages to create an independent 3D respiratory motion with 22 mm maximum range for target and a 5 mm 1D sinusoidal motion in the OAR. The biology-tracking zone (BTZ) was generated by adding 5 mm margin to the motion extent. The three BgRT scenarios studied were representative of tumors with good (8:1), borderline (4:1) and undesired (2:1) PET biodistributions compared to background. The clinical safety limit of BgRT uses Activity Concentration within the BTZ (AC ≥ 5 kBq/ml) and Normalized Target Signal as a contrast metric (NTS ≧ 2.7 for planning and ≧ 2 for delivery). The BgRT deliveries were repeated 3 times with radiochromic film and integrated ion chamber capturing the target and OAR doses. Tracked dosimetry was assessed using a margin-loss calculation defined as the maximum linear difference in distance between the planned and delivered 97% prescription iso-dose lines.

RESULTS

The imaging-only PET images used to create BgRT plans had an AC of 7.0, 5.3, and 1.6 kBq/ml with an NTS of 6.8, 5.3, and 1.8 for 8:1, 4:1, and 2:1 concentrations, respectively. Qualitatively, the target was not visible on the planning PET images 2:1 loading scenario. At delivery, the mean pre-scan activity concentrations were 6.8, 4.7, and 3.7 kBq/ml with corresponding mean NTS of 3.7, 2.6, 1.5 for 8:1, 4:1 and 2:1 deliveries. The pre-scan values of AC or NTS did not satisfy the clinical system safety limits for 4:1 and 2:1 ratio experiments, but the engineering software allowed for the delivery to capture the resulting doses. The deliveries showed a prescription dose coverage to the CTV of 100% for the 8:1 and 4:1 cases, but 88% for the 2:1 case. When compared to the planned dose values, the delivered minimum doses were -7.6%, -8.6% and -10.9%, whereas the maximum dose differences in CTV were 1.2%, 0% and -4.8% of the planned dose distributions of the 8:1, 4:1 and 2:1 cases, respectively. Calculated margin losses were -2.3, -3.8, and -5.5 mm, for the 8:1, 4:1, and 2:1 cases, respectively. The maximum OAR doses were less than the maximum doses predicted on the bounded DVH curves for all scenarios.

CONCLUSION

With sufficient tracer uptake in the target, BgRT can deliver tracked dosimetry for targets with a large respiratory motion profile. Both the good BgRT candidate and borderline cases produced clinically acceptable delivered doses, even though the borderline case was flagged by the clinical system safety checks. As expected, the delivered BgRT dose distributions were suboptimal with reduced tumor over background PET contrast.

Tuning the Acid-Base Properties of Lignin-Derived Carbon Modulated ZnZr/SiO2 Catalysts for Selective and Efficient Production of Butadiene from Ethanol

The direct selective conversion of ethanol to butadiene (ETB) is a competitive and environmentally friendly process compared to the traditional crude cracking route. The acid-base properties of catalysts are crucial for the direct ETB process. Herein, we report a rationally designed multifunctional lignin-derived carbon-modulated ZnZr/SiO2 (L-ZnZr/SiO2) catalyst with suitable acid-base properties for the direct ETB reaction. A variety of characterization techniques are employed to investigate the relationship between the acid-base properties and catalytic performance of the multifunctional lignin-modulated ZnZr/SiO2 catalysts. The results revealed that the rationally additional lignin-modulated carbon enhances both the acidity and basicity of the ZnZr/SiO2 catalysts, providing a suitable acid-base ratio that boosts the direct ETB reactivity. Meanwhile, the 1% L-ZnZr/SiO2 catalyst possessed ethanol conversion and butadiene selectivity as high as 98.4% and 55.5%, respectively, and exhibited excellent catalytic stability.

Differentiated Fractionation of Various Biomass Resources by p-Toluenesulfonic Acid at Mild Conditions

Biomass is the ideal substitute for petrochemical resources because of its renewable and abundant sources. p-Toluenesulfonic acid (p-TsOH) can effectively separate lignin from biomass under mild conditions, so it is highly expected in biomass fractionation to improve the utilization efficiency. In this study, we investigated the effect of p-TsOH differentiated fractionation of poplar sawdust, eucalyptus sawdust, and rice straw below 100 °C. According to the experimental results, upon pretreatment by p-TsOH of the three kinds of raw biomass, most of the lignin and hemicellulose of poplar sawdust and eucalyptus sawdust were removed, whereas the cellulose was retained, but most of the hemicellulose and cellulose of rice straw were kept, whereas the lignin was removed at similar conditions. The structures and compositions of pretreatment residues, lignin, and hemicellulose extracted from raw biomass were characterized by XRD, FTIR, HSQC-NMR, XPS, and SEM. The differentiated fractionation mechanism of biomass was analyzed. A better recognition and understanding of the factors affecting biomatrix opening and fractionation will allow for the identification of new pretreatment strategies that improve biomass utilization and permit the rational enzymatic hydrolysis of cellulose.

[Long-term mortality risk of valvular heart disease adults over 35 years old in Chinese communities]

Objective: To investigate the risk and influencing factors of long-term mortality of valvular heart disease (VHD) adults aged 35 years and over in Chinese communities. Methods: A cohort study was carried out. The data of the subjects who underwent echocardiography were collected from the Chinese Hypertension Survey between 2012 and 2015 and survival outcomes were followed up between 2018 and 2019. Kaplan-Meier survival curves were plotted and compared using log-rank test. Cox proportional hazards models were used to analyze the influence of VHD on mortality. Results: During an average follow-up time of (4.6±0.9) years, a total of 23 237 participants (10 881 males and 12 356 females) were pooled into the final analysis from 5 eastern, 5 central, and 4 western provinces, cities and autonomous regions in China, with a mean age of (56.9±13.2) years. Among the included participants, 1 004 had VHD (467 males and 537 females), with a mean age was of (68.1±12.6) years. In the Kaplan-Meier analysis, participants with VHD had a significantly increased risk of all-cause mortality (log-rank χ²=351.82, P<0.001) and cardiovascular mortality (log-rank χ²=284.14, P<0.001) compared with those without VHD. Multivariate Cox regression analysis showed that compared with those without VHD, the participants with rheumatic VHD had a 45% increased risk of all-cause mortality (HR=1.45, 95%CI: 1.12-1.89) and degenerative VHD increased the risk of cardiovascular mortality by 69% (HR=1.69, 95%CI: 1.19-2.38). The risk factors of cardiovascular mortality for VHD were age 55 years and over (55-<75 years: HR=4.93, 95%CI: 1.17-20.85;≥75 years: HR=11.92, 95%CI: 2.85-49.80) and diabetes mellitus (HR=1.71, 95%CI: 1.00-2.93). Conclusions: VHD is a risk factor of all-cause mortality and cardiovascular mortality among adults aged 35 years and over. Age 55 years and over and diabetes mellitus are adverse prognostic factors for patients with VHD.

Design and Synthesis of Porous Organic Polymers: Promising Catalysts for Lignocellulose Conversion to 5-Hydroxymethylfurfural and Derivates

In the face of the current energy and environmental problems, the full use of biomass resources instead of fossil energy to produce a series of high-value chemicals has great application prospects. 5-hydroxymethylfurfural (HMF), which can be synthesized from lignocellulose as a raw material, is an important biological platform molecule. Its preparation and the catalytic oxidation of subsequent products have important research significance and practical value. In the actual production process, porous organic polymer (POP) catalysts are highly suitable for biomass catalytic conversion due to their high efficiency, low cost, good designability, and environmentally friendly features. Here, we briefly describe the application of various types of POPs (including COFs, PAFs, HCPs, and CMPs) in the preparation and catalytic conversion of HMF from lignocellulosic biomass and analyze the influence of the structural properties of catalysts on the catalytic performance. Finally, we summarize some challenges that POPs catalysts face in biomass catalytic conversion and prospect the important research directions in the future. This review provides valuable references for the efficient conversion of biomass resources into high-value chemicals in practical applications.

A tera-electron volt afterglow from a narrow jet in an extremely bright gamma-ray burst

Some gamma-ray bursts (GRBs) have a tera-electron volt (TeV) afterglow, but the early onset of this has not been observed. We report observations with the Large High Altitude Air Shower Observatory of the bright GRB 221009A, which serendipitously occurred within the instrument field of view. More than 64,000 photons >0.2 TeV were detected within the first 3000 seconds. The TeV flux began several minutes after the GRB trigger, then rose to a peak about 10 seconds later. This was followed by a decay phase, which became more rapid ~650 seconds after the peak. We interpret the emission using a model of a relativistic jet with half-opening angle ~0.8°. This is consistent with the core of a structured jet and could explain the high isotropic energy of this GRB.

Surfactants facilitated glycerol organosolv pretreatment of lignocellulosic biomass by structural modification for co-production of fermentable sugars and highly reactive lignin

This study reported that surfactants could facilitate the organosolv pretreatment of lignocellulosic biomass (LCB) to produce fermentable sugars and highly active lignin. Under the optimized conditions, the surfactant-assisted glycerol organosolv (saGO) pretreatment achieved 80.7% delignification with a retention of 93.4% cellulose and 83.0% hemicellulose. The saGO pretreated substrate exhibited an excellent enzymatic hydrolyzability, achieving 93% of glucose yield from the enzymatic hydrolysis at 48 h. Structural analysis showed that the saGO lignin contained rich β-O-4 bondings with less repolymerization and lower phenolic hydroxyl groups, thus forming highly reactive lignin fragments. The analysis evidenced that the surfactant graft the lignin by structural modification, which was responsible for the excellent substrate hydrolyzability. The co-production of fermentable sugars and organosolv lignin almost recovered a gross energy (87.2%) from LCB. Overall, the saGO pretreatment holds a lot of promise for launching a novel pathway towards lignocellulosic fractionation and lignin valorization.

Wood-derived bio-coating materials incorporating hydrophobic lignin and hierarchically porous biochar for high-efficiency coating slow-release fertilizers

Coating slow-release fertilizers (CSRFs) have gained significant attention for their potential to improve nutrient utilization efficiency and prevent environmental pollution through mitigating soil and water contamination. This study developed a novel wood waste-derived composition as a bio-coating material for urea slow-release by integrating modified lignin (PCL) and activated biochar (ABC). PCL was prepared by grafting palmitoyl chloride (PC) with hydrophobic groups to the lignin via an esterification reaction. ABC with a high surface area and hierarchically porous structure created rich channels for ion transportation. These results increased the water-retention ability with a reduced absorbing/expelling rate and confer an excellent Cr(VI) adsorption capacity to the PCL and ABC hybrid coating material (PCL/ABC). The as-prepared PCL/ABC-based CSRF (PCL/ABC-CSRF) showed improving fertilizer slow-release properties for real application (nitrogen release persistence for 40 days at soil). The rice (Oryza sativa L.) hydroponics study suggested that such novel PCL/ABC was conducive to the rice growth in micro metallic contaminated hydroponics by eliminating the accumulation of chromium metal in rice roots. Overall, this study provides an attractive platform for developing biodegradable, heavy-metal adsorbable, and high-efficient CSRFs and a feasible and effective way for functionalized utilization of wood waste.

Efficient preparation of nitrogen-doped lignin-based carbon nanotubes and the selectivity of nitrogen speciation for photothermal therapy

In this study, the lignin was pre-modified using small-molecule nitrogen-containing compounds, and then the nitrogen-doped lignin-based carbon nanotubes (L-NCNTs) were fabricated by pyrolysis using the modified lignin as raw materials. The obtained L-NCNTs were multi-walled carbon nanotubes with diameters between 10 and 80 nm. The modification of lignin had an important effect on the nitrogen morphology of L-NCNTs, and promoted the high selectivity of pyridine-N in the L-NCNTs. Defects and pyridinic-N structure were conducive to boosting photothermal properties of the L-NCNTs. The photothermal conversion efficiency of the L-NCNTs after 808 nm laser irradiation for 5 min reached 58.8 %. The L-NCNTs can be used as photothermal agents in drug delivery system to achieve mild photothermal therapy, and it is basically non-toxic to normal cells, indicating good biocompatibility. This work provides new ideas for development of lignin-based high value-added products from biomass.

[Prevalence of albuminuria and its association with cardiovascular diseases in Chinese residents aged over 35 years]

Objective: To investigate the prevalence of albuminuria in Chinese residents aged >35 years and its potential association with cardiovascular disease (CVD). Methods: A total of 34 647 Chinese subjects aged ≥35 years were selected by stratified multi-stage random sampling from 2012 to 2015. Data were collected through questionnaires, physical examinations, and laboratory tests. Albuminuria was categorized into 3 types according to urinary albumin-to- creatinine ratio: normal (<30 mg/g), microalbuminuria (MAU, 30-300 mg/g), and macroalbuminuria (≥300 mg/g). Measurement data were expressed as x¯±s, and t-tests were used for comparisons between indicators. Qualitative data were expressed as rate or constituent ratio, and the χ² test or Kruskal-Wallis test was used to examine differences. Logistic regression was used for multivariate analyses. SAS 9.4 software was used for statistical analyses, and P<0.05 was considered statistically significant. Results: The prevalence of abnormal albuminuria was 19.1%; the prevalence was 17.2% for MAU and lower in males (13.8%) than females (20.1%, P<0.01). The risk of CVD was higher among subjects with MAU (OR=1.23, 95%CI 1.12-1.35) and macroalbuminuria (OR=1.86, 95%CI 1.50-2.32). When MAU was complicated by hypertension and diabetes mellitus, the CVD risk was 1.76 times higher. Conclusions: The prevalence of MAU is high among Chinese subjects aged 35 years and over. Those with MAU have higher CVD risk, especially those with hypertension and diabetes mellitus.

[Current status of hypertension prevalence, treatment and control rate among young and middle-aged population in China]

Objective: To estimate the prevalence, awareness, treatment and control rate of hypertension among young and middle-aged population in China. Methods: The analysis was based on the results of 2012-2015 China Hypertension Survey, which was a cross-sectional stratified multistage random sampling survey. A total of 229 593 subjects were included in the final analysis. The data including sex, age, living in urban and rural areas, prevalence of hypertension, history of stroke, family history of coronary heart disease and drinking, physical examination, heart rate were collected. Hypertension was defined as mean systolic blood pressure (SBP) ≥140 mmHg (1 mmHg=0.133 kPa), and (or) diastolic blood pressure (DBP) ≥90 mmHg, and (or) self-report a history of hypertension, and (or) use of antihypertensive medicine within 2 weeks before survey. Prehypertension was defined as SBP between 120-139 mmHg, and (or) DBP between 80-89 mmHg. Control of hypertension was considered for hypertensive individuals with SBP<140 mmHg and DBP<90 mmHg. The prevalence of prehypertension, hypertension, awareness, treatment, control rate were calculated, and the control rate among those with antihypertensive medication was also calculated. Results: The prevalence of prehypertension and hypertension was 43.8% (95%CI: 42.3%-45.4%), and 22.1% (95%CI: 20.8%-23.3%), respectively. The prevalence of prehypertension and hypertension was significantly higher among male than female across different age groups. The awareness, treatment, control rate of hypertension and control rate among treated hypertensive participants were 43.8%, 33.2%, 16.7%, and 40.2%, respectively. The prevalence was higher, and the control rate was lower among individuals with higher heart rate. Conclusion: The prevalence of prehypertension and hypertension among young and middle-aged population is high, the awareness, treatment and control rate need to be further improved in this population. The prevention and treatment of hypertension should be strengthened in the future to improve the control rate of hypertension in China.

Constraints on Heavy Decaying Dark Matter from 570 Days of LHAASO Observations

The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying the northern γ-ray sky at energies above 10 TeV with unprecedented sensitivity. γ-ray observations have long been one of the most powerful tools for dark matter searches, as, e.g., high-energy γ rays could be produced by the decays of heavy dark matter particles. In this Letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340 days of data from 1/2-KM2A and 230 days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after γ/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest γ-ray constraints on the lifetime of heavy dark matter particles with mass between 10^{5} and 10^{9}  GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.

Preparation of lignin modified hyper-cross-linked nanoporous resins and their efficient adsorption for p-nitrophenol in aqueous solution and CO2 capture

A series of lignin modified hyper-cross-linked nanoporous resins (LMHCRs) had been synthesized from lignin, 4-vinylbenzyl chloride, and divinylbenzene by free radical polymerization reaction and following Friedel-Crafts reaction. The results indicated that Brunauer-Emmett-Teller surface area (S_BET) of LMHCRs decreased with different degrees compared with polymeric microspheres (HCRs) without adding lignin. With increasing the feeding amount of lignin, the S_BET of LMHCRs first increased and then decreased, and LMHCR-2 had larger S_BET (968.52 m²/g) and average pore size (D_A: 2.51 nm). Meanwhile, their contact angle continuously decreased from 92.1⁰ to 71.3⁰, indicating the enhanced polarity. Interestingly, the adsorption capacity of p-nitrophenol (PNP) on all LMHCRs were obviously higher than rhodamine B, and LMHCR-2 had the largest capacity ratio (3.780) of PNP to rhodamine B or other organic dyes at 298 K. Specifically, the Q_m of PNP on LMHCR-2 reached the largest value (492.1 mg/g) due to its suitable porosity and favorable surface polarity. LMHCR-2 also displayed excellent CO₂ capture (86.5 mg/g) at 273 K and 1 bar and good reusability. This study provided an efficient route to modify hyper-cross-linked resin by using the residual lignin, and showed the enhanced adsorption performance.

[Investigate developmental coordination disorder of kindergarten children in Zhejiang Province]

In order to investigate developmental coordination disorder (DCD) of kindergarten children in Zhejiang province, 200 ordinary kindergartens were randomly selected by stratified random sampling in 11 prefecture-level cities of Zhejiang Province, and 38 900 children from 1 000 classes in each grade were then randomly selected into the study from June 2019 to December 2019. The Little DCD Questionnaire and a self-designed questionnaire were used to screen the DCD of those children. There were 36 807 valid questionnaires, and 6.50% (2 391/36 807) of them were positive results. The results showed that boy, age ≤5 years, overweight or obesity, left handedness, comorbidity with motor or developmental disorders and premature infants were risk factors of DCD in children. As for parents and families, maternal gestational age<20 years, maternal overweight or obesity before pregnancy, low-middle level education of parents, direct family and low income of family were also associated with DCD in children. Therefore, it is necessary to conduct early prevention and intervention strategies targeting on identified risk factors among relevant population.

Effects of aerobic exercise on inflammatory factors in healthy adults: a meta-analysis

OBJECTIVE

With this meta-analysis we aimed at systematically evaluating the intervention effects of aerobic exercise on inflammatory factors in healthy adults and identifying an optimal aerobic exercise program with anti-inflammatory effects.

MATERIALS AND METHODS

Four databases, including PubMed, Web of Science, Cochrane Library and SPORTDiscus, were searched from inception until April 30, 2021. Stata version 11.0 was used for data analysis.

RESULTS

A total of 15 studies with 1160 participants were included. The pooled estimates showed that aerobic exercise could significantly reduce TNFα levels (SMD=-0.30, 95% CI: -0.58 - -0.03, p=0.032), while the levels of IL-6 (SMD=-0.14, 95% CI: -0.32-0.03, p=0.109) and CRP (SMD=-0.09, 95% CI: -0.34-0.16, p=0.484) were not significantly affected.

CONCLUSIONS

Aerobic exercise exerts a positive effect by preventing inflammation-related diseases.

Exploring Lorentz Invariance Violation from Ultrahigh-Energy γ Rays Observed by LHAASO

Recently, the LHAASO Collaboration published the detection of 12 ultrahigh-energy γ-ray sources above 100 TeV, with the highest energy photon reaching 1.4 PeV. The first detection of PeV γ rays from astrophysical sources may provide a very sensitive probe of the effect of the Lorentz invariance violation (LIV), which results in decay of high-energy γ rays in the superluminal scenario and hence a sharp cutoff of the energy spectrum. Two highest energy sources are studied in this work. No signature of the existence of the LIV is found in their energy spectra, and the lower limits on the LIV energy scale are derived. Our results show that the first-order LIV energy scale should be higher than about 10^{5} times the Planck scale M_{Pl} and that the second-order LIV scale is >10^{-3}M_{Pl}. Both limits improve by at least one order of magnitude the previous results.

Facile preparation of oxygen-rich porous polymer microspheres from lignin-derived phenols for selective CO2 adsorption and iodine vapor capture

Lignin is a natural O-containing aromatic amorphous polymers from the residues of biorefinery and industrial papermaking, it can derive lots of aromatic phenol chemicals used as industrial raw materials by an efficient depolymerization, and then produce synthetic polymers. Here, we selected six aromatic units from the liquid products of lignin depolymerization, and tried to prepare diversified O-rich hyper-cross-linked polymers (HCPs) by one-pot Friedel-Crafts alkylation reaction for CO₂ and iodine vapor capture. HCP1, HCP2, and HCP3 microspheres possessed similar porous structure with Brunauer-Emmett-Teller (BET) surface areas (S_BET) of 14.1-20.6 m²/g and high O content (26.34-30.68 wt%), while HCP4, HCP5, and HCP6 were composed of many bulks with 3D networks structure, and showed larger S_BET of 15.4-246.9 m²/g and relatively low O content (18.48-26.38 wt%). The results indicated that the chemical position and quantities of substituent groups (methoxy and alkyl) into lignin-derived units had evident impact on their morphology and textural parameters. These HCPs exhibited considerable CO₂ uptake (64.1 mg/g) and selectivity (35.2) at 273 K， and high iodine vapor uptake (192.3 wt%). Moreover, the performance analysis implied that the S_BET and pore volume of these HCPs had not played the dominated roles in the CO₂ and I₂ adsorption, while their pore size distribution, O-functional groups, and electron density will be more important for the capture of the both. This study will offer a facile synthesis of O-rich polymer microsphere adsorbents based on the green and sustainable lignin.

Versatile Strategy for the Preparation of Woody Biochar with Oxygen-Rich Groups and Enhanced Porosity for Highly Efficient Cr(VI) Removal

Biochar is widely used to remove hexavalent chromium [Cr(VI)] from wastewater through adsorption, which is recognized as a facile, cost-efficient, and high-selectivity approach. In this study, a versatile strategy that combines delignification with subsequent carbonization and KOH activation is proposed to prepare a novel woody biochar from waste poplar sawdust. By virtue of the unique multilayered and honeycomb porous structure induced by delignification and activation processes, the resultant activated carbonized delignified wood (ACDW) exhibits a high specific surface area of 970.52 m2 g-1 with increasing meso- and micropores and abundant oxygen-containing functional groups. As a benign adsorbent for the uptake of Cr(VI) in wastewater, ACDW delivers a remarkable adsorption capacity of 294.86 mg g-1 in maximum, which is significantly superior to that of unmodified counterparts and other reported biochars. Besides, the adsorption behaviors fit better with the Langmuir isotherm, the pseudo-second-order kinetic model, and the adsorption diffusion model in batch experiments. Based on the results, we put forward the conceivable adsorption mechanism that the synergistic contributions of the capillary force, electrostatic attraction, chemical complexation, and reduction action facilitate the Cr(VI) capture by ACDW.

[Development of a fluorescent recombinase-aided isothermal amplification-based nucleic acid assay for detection of Leishmania]

OBJECTIVE

To develop a fluorescent recombinase-aided isothermal amplification (RAA)-based nucleic acid assay for detection of Leshimania.

METHODS

Specific primers and probes were designed targeting Leishmania internal transcribed spacer 1 (ITS1) gene for RAA assay, and a fluorescent RAA assay was developed for detection of Leishmania following screening of primer pairs and optimization of primer and probe concentrations. The sensitivity of RAA assay for detection of Leishmania was evaluated using recombinant plasmid containing Leishmania ITS1 gene sequences at different copies and Leshimania genomic DNA at different concentrations as templates, and the specificity of RAA assay for detection of Leishmania was evaluated using the genomic DNA of transfusion-transmitted parasites, including Babesia microti, Toxoplasma gondii, Plamodium vivax, P. ovale, P. falciparum, P. malariae, L. donovani and L. infantum.

RESULTS

After the optimal primer pair was screened from 9 pairs of primer combinations, the final primer and probe concentrations were optimized as 0.3 μmol/L and 0.08 μmol/L, respectively. Nucleic acid detection of Leishmania was completed by the fluorescent RAA assay at an isothermal temperature of 39 °C within 20 min. Remarkable florescent signals were seen within 5 min following RAA detection of genomic DNA of L. donovani and L. infantum, and no cross-reactions were observed with B. microti, T. gondii, P. vivax, P. ovale, P. falciparum or P. malariae. The lowest limitation of detection of the fluorescent RAA assay was 10 copies/μL recombinant plasmid containing Leishmania ITS1 gene sequences and 1 fg/μL Leishmania genomic DNA.

CONCLUSIONS

A rapid, simple, sensitive and specific fluorescent RAA assay is successfully developed for detection of L. donovani and L. infantum, which is effective for field screening of leishmaniasis.

Peta-electron volt gamma-ray emission from the Crab Nebula

The Crab Nebula is a bright source of gamma rays powered by the Crab Pulsar's rotational energy through the formation and termination of a relativistic electron-positron wind. We report the detection of gamma rays from this source with energies from 5 × 10^-4 to 1.1 peta-electron volts with a spectrum showing gradual steepening over three energy decades. The ultrahigh-energy photons imply the presence of a peta-electron volt electron accelerator (a pevatron) in the nebula, with an acceleration rate exceeding 15% of the theoretical limit. We constrain the pevatron's size between 0.025 and 0.1 parsecs and the magnetic field to ≈110 microgauss. The production rate of peta-electron volt electrons, 2.5 × 10³⁶ ergs per second, constitutes 0.5% of the pulsar spin-down luminosity, although we cannot exclude a contribution of peta-electron volt protons to the production of the highest-energy gamma rays.

[Role of gut-liver-immune axis in the pathogenesis of nonalcoholic steatohepatitis]

Nonalcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease in the world. Liver cirrhosis, liver cancer and a variety of extrahepatic chronic diseases are important risk factors for NAFLD. Currently, there is still a lack of effective therapeutic drugs. Liver inflammation is a key driving factor for the progression of NAFLD, so regulating liver inflammation may provide a potential means to delay and reverse the progression of nonalcoholic steatohepatitis (NASH). Studies have found that the gut-liver-immune axis plays an important role in the progression of NASH. Gut microbiota can use its metabolites to induce glycolipid toxicity, oxidative stress and intestinal barrier damage, while bacterial components such as lipopolysaccharides, peptidoglycans, bacterial DNA and extracellular vesicles can translocate into the liver through the damaged intestinal barrier, causing excessive activation of immune cells, thus aggravating liver inflammation and promoting the progress of NASH. This paper focuses on the gut-liver-immune axis to analyze the gut microbiota mediated liver immunity and its mechanism in the occurrence and development of NASH, so as to lay a theoretical foundation for the research and development of new therapeutic strategies for NASH.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Extended Very-High-Energy Gamma-Ray Emission Surrounding PSR J0622+3749 Observed by LHAASO-KM2A

We report the discovery of an extended very-high-energy (VHE) gamma-ray source around the location of the middle-aged (207.8 kyr) pulsar PSR J0622+3749 with the Large High-Altitude Air Shower Observatory (LHAASO). The source is detected with a significance of 8.2σ for E>25  TeV assuming a Gaussian template. The best-fit location is (right ascension, declination) =(95.47°±0.11°,37.92°±0.09°), and the extension is 0.40°±0.07°. The energy spectrum can be described by a power-law spectrum with an index of -2.92±0.17_{stat}±0.02_{sys}. No clear extended multiwavelength counterpart of the LHAASO source has been found from the radio to sub-TeV bands. The LHAASO observations are consistent with the scenario that VHE electrons escaped from the pulsar, diffused in the interstellar medium, and scattered the interstellar radiation field. If interpreted as the pulsar halo scenario, the diffusion coefficient, inferred for electrons with median energies of ∼160  TeV, is consistent with those obtained from the extended halos around Geminga and Monogem and much smaller than that derived from cosmic ray secondaries. The LHAASO discovery of this source thus likely enriches the class of so-called pulsar halos and confirms that high-energy particles generally diffuse very slowly in the disturbed medium around pulsars.

Ultrahigh-energy photons up to 1.4 petaelectronvolts from 12 γ-ray Galactic sources

The extension of the cosmic-ray spectrum beyond 1 petaelectronvolt (PeV; 10¹⁵ electronvolts) indicates the existence of the so-called PeVatrons-cosmic-ray factories that accelerate particles to PeV energies. We need to locate and identify such objects to find the origin of Galactic cosmic rays¹. The principal signature of both electron and proton PeVatrons is ultrahigh-energy (exceeding 100 TeV) γ radiation. Evidence of the presence of a proton PeVatron has been found in the Galactic Centre, according to the detection of a hard-spectrum radiation extending to 0.04 PeV (ref. ²). Although γ-rays with energies slightly higher than 0.1 PeV have been reported from a few objects in the Galactic plane^3-6, unbiased identification and in-depth exploration of PeVatrons requires detection of γ-rays with energies well above 0.1 PeV. Here we report the detection of more than 530 photons at energies above 100 teraelectronvolts and up to 1.4 PeV from 12 ultrahigh-energy γ-ray sources with a statistical significance greater than seven standard deviations. Despite having several potential counterparts in their proximity, including pulsar wind nebulae, supernova remnants and star-forming regions, the PeVatrons responsible for the ultrahigh-energy γ-rays have not yet been firmly localized and identified (except for the Crab Nebula), leaving open the origin of these extreme accelerators.