Benchmark experiment on slab^(238)U with D-T neutrons for validation of evaluated nuclear data

A benchmark experiment on^(238)U slab samples was conducted using a deuterium-tritium neutron source at the China Institute of Atomic Energy.The leakage neutron spectra within energy levels of 0.8-16 MeV at 60°and 120°were measured using the time-of-flight method.The samples were prepared as rectangular slabs with a 30 cm square base and thicknesses of 3,6,and 9 cm.The leakage neutron spectra were also calculated using the MCNP-4C program based on the latest evaluated files of^(238)U evaluated neutron data from CENDL-3.2,ENDF/B-Ⅷ.0,JENDL-5.0,and JEFF-3.3.Based on the comparison,the deficiencies and improvements in^(238)U evaluated nuclear data were analyzed.The results showed the following.(1)The calculated results for CENDL-3.2 significantly overestimated the measurements in the energy interval of elastic scattering at 60°and 120°.(2)The calculated results of CENDL-3.2 overestimated the measurements in the energy interval of inelastic scattering at 120°.(3)The calculated results for CENDL-3.2 significantly overestimated the measurements in the 3-8.5 MeV energy interval at 60°and 120°.(4)The calculated results with JENDL-5.0 were generally consistent with the measurement results.

Hi'CT:a pixel sensor-based device for ion tomography

Carbon ions,commonly referred to as particle therapy,have become increasingly popular in the last decade.Accurately predicting the range of ions in tissues is important for the precise delivery of doses in heavy-ion radiotherapy.Range uncertainty is currently the largest contributor to dose uncertainty in normal tissues,leading to the use of safety margins in treatment planning.One potential method is the direct relative stopping measurement(RSP)with ions.Heavy-ion CT(Hi′CT),a compact segmented full digital tomography detector using monolithic active pixel sensors,was designed and evaluated using a 430 MeV/u high-energy carbon ion pencil beam in Geant4.The precise position of the individual carbon ion track can be recorded and reconstructed using a 30μm×30μm small pixel pitch size.Two types of customized image reconstruction algorithms were developed,and their performances were evaluated using three different modules of CAT-PHAN 600-series phantoms.The RSP measurement accuracy of the tracking algorithm for different types of materials in the CTP404 module was less than 1%.In terms of spatial resolution,the tracking algorithm could achieve a 20%modulation transfer function normalization value of CTP528 imaging results at 5 lp/cm,which is significantly better than that of the fast imaging algorithm(3 lp/cm).The density resolution obtained using the tracking algorithm of the customized CTP515 was approximately 10.5%.In conclusion,a compact digital Hi'CT system was designed,and its nominal performance was evaluated in a simulation.The RSP resolution and image quality provide potential feasibility for scanning most parts of an adult body or pediatric patient,particularly for head and neck tumor treatment.

Hformer:highly efficient vision transformer for low-dose CT denoising

In this paper,we propose Hformer,a novel supervised learning model for low-dose computer tomography(LDCT)denoising.Hformer combines the strengths of convolutional neural networks for local feature extraction and transformer models for global feature capture.The performance of Hformer was verified and evaluated based on the AAPM-Mayo Clinic LDCT Grand Challenge Dataset.Compared with the former representative state-of-the-art(SOTA)model designs under different architectures,Hformer achieved optimal metrics without requiring a large number of learning parameters,with metrics of33.4405 PSNR,8.6956 RMSE,and 0.9163 SSIM.The experiments demonstrated designed Hformer is a SOTA model for noise suppression,structure preservation,and lesion detection.

The immune profiles and “minimizing tacrolimus” strategy for long-term survival recipients after liver transplantation

To the Editor:Liver transplantation(LT)has become a major and effective therapeutic approach for end-stage liver disease[1].However,10-year graft and patient survival rates remained low with 54%and 61%,respectively[2].Improving the outcome of long-term LT has become a major focus of the transplantation community.

Penile metastasis from rectal carcinoma: A case report

BACKGROUND Metastasis to the penis is an unusual event,and penile metastasis from rectal carcinoma(PMRC)is extremely rare and associated with a dismal prognosis.Thus far,approximately 80 cases have been reported.CASE SUMMARY Herein,we report the case of a 49-year-old man with PMRC.The patient presented to the urology clinic with a complaint of penile pain during urination.The patient underwent the Dixon operation for rectal carcinoma 2 mo before the presentation.During hospitalisation,abdominal computed tomography revealed a nodular lesion on the left penis.The postoperative pathological examination revealed a typical intestinal-type adenocarcinoma.Previous cases of PMRC were retrieved from PubMed to characterise the clinicopathological features and identify the prognostic factors of PMRC.CONCLUSION The analysis suggested that approximately 24 mo is the median time to metastasis occurrence and 150 d is the survival time after diagnosis.Furthermore,poor pathological differentiation,lymph node involvement of the primary RC,metastasis time<6 mo,penile metastatic nodule diameter>1 cm,and treatment abandonment are negative predictors of survival outcomes.Close follow-up,surgical resection,chemotherapy,and radiotherapy may potentially improve the prognosis of patients.

Research Progress in the Fabrication of Covalent Organic Framework Membranes for Chemical Separations

Membrane technology has become one of the most promising separation technologies for its energy saving, high separation efficiency, environmental friendliness, and economic feasibility. Covalent organic frameworks(COFs) with intrinsically high porosity, controllable pore size, uniform pore size distribution and long-range ordered channel structure, have emerged as next-generation materials to fabricate advanced separation membranes. This feature article summarizes some latest studies in the development of pure COF membranes in our lab, including their fabrication and applications in chemical separations. Finally, current challenges facing high-performance COF separation membranes are discussed.

Design and synthesis of liquid crystal copolyesters with high-frequency low dielectric loss and inherent flame retardancy

Ultra-low dielectric loss(Df)and low dielectric constant(Dk)materials are urgently required in highspeed and large-capacity transmission,in which the wholly aromatic liquid crystal polymer(LCP)has gained attention due to its excellent dielectric properties.However,the relationship between molecular structure and dielectric properties is still not clear.In this study,two copolyesters containing phenyl or naphthyl structures are synthesized,as well as the effects of benzene and naphthalene mesogens on dielectric properties are investigated.The synthesized copolyesters containing naphthalene structure have good comprehensive properties with high thermal stability(T_(5%)=479℃ and T_g=195-216℃),inherent flame retardance(LOI=33.0-35.0 and UL-94 V-0 level at 0.8 mm),low Dk(2.9-3.0@10 GHz)and low Df(0.0027-0.0047@10 GHz).Naphthalene mesogen can reduce the dielectric loss more significantly than benzene at high frequency by reducing the density and mobility of polarizable groups,which leads to the effectively limited dipole polarization in copolyesters.Consequently,we proposed a new strategy for designing low Dk and low Df materials.

Exosome-derived galectin-9 may be a novel predictor of rejection and prognosis after liver transplantation

Acute cellular rejection(ACR) remains a major concern after liver transplantation.Predicting and monitoring acute rejection by non-invasive methods are very important for guiding the use of immunosuppressive drugs.Many studies have shown that exosomes and their contents are potential biomarkers for various liver diseases.Here,we identify and validate the role of exosomes and galectin-9 in ACR after liver transplantation.Exosomes were isolated from three sets of paired patients,with and without ACR,and the proteins within the exosomes were isolated and identified.Candidate proteins were then validated using a tissue microarray containing resected liver samples from 73 ACR and 63 non-rejection patients.Finally,protein expression and clinical manifestations were included in KaplanMeier survival and Cox regression analyses.Circulating exosomes were isolated from ACR and non-rejection patients and characterized using transmission electron microscopy and western blotting for CD63/CD81.Western blotting experiments revealed higher levels of galectin-9 protein in circulating exosomes from ACR recipients.Immunohistochemical analysis of the tissue microarray showed that the expression of galectin-9 in resected liver was significantly higher in the ACR group than in the non-rejection group(P<0.05).Higher levels of galectin-9 expression in resected livers were associated with poorer prognosis(P<0.05).Exosome-derived galectin-9 may be a novel predictor of rejection and prognosis after liver transplantation.

Identification of a serum three-microRNA signature for cervical cancer diagnosis

To the Editor:Cervical cancer(CC)is one of the leading causes of cancer deaths in women around the world.[1]In clinical practice,screening methods such as human papillomavirus testing and cytology-based detection have the disadvantages of having a high false rate,being hysteretic or ineffective.[2]Novel non-invasive biomarkers that can help diagnose CC with higher specificity and sensitivity are in great demand.MicroRNA(miRNA)is a type of non-coding small RNA of 18 to 25 nucleotides in length.Circulating miRNAs show the great potential of being cancer biomarkers for the stable existence in peripheral serum or plasma.[3]In this study,we performed a four-stage experiment using a total of 108 CC and 108 normal control(NC)serum samples to explore the diagnostic potential of serum miRNAs in CC.The schematic diagram of the experimental procedure was shown in Supplementary Figure 1,http://links.lww.com/CM9/A429.

A coordination compound featuring a supramolecular hydrogen-bonding network for proton conduction

A new coordination compound [Mg（L）（H2 O）5·H2 O]（NKU-109, H2 L=5-（4 H-1,2,4-triazol-4-yl）benzene-1,3-dicarboxylic acid） was solvothermally synthesized, featuring a supramolecular hydrogen-bonding network. A good proton conductivity of 5.87×10^-4S/cm was recorded at 70℃ and a relative humidity of75% in alternating current（AC） impedance experiment, which sheds a new light on the design of proton conduction materials based on coordination compounds.