Simultaneous fluorescence and Compton scattering computed tomography based on linear polarization X-ray

Purpose To propose a method for simultaneous fluorescence and Compton scattering computed tomography by using linearly polarized X-rays.Methods Monte Carlo simulations were adopted to demonstrate the feasibility of the proposed method.In the simulations,the phantom is a polytetrafluoroethylene cylinder inside which are cylindrical columns containing aluminum,water,and gold(Au)-loaded water solutions with Au concentrations ranging between 0.5 and 4.0 wt%,and a parallel-hole collimator imaging geometry was adopted.The light source was modeled based on a Thomson scattering X-ray source.The phantom images for both imaging modalities were reconstructed using a maximumlikelihood expectation maximization algorithm.Results Both the X-ray fluorescence computed tomography(XFCT)and Compton scattering computed tomography(CSCT)images of the phantom were accurately reconstructed.A similar attenuation contrast problem for the different cylindrical columns in the phantom can be resolved in the XFCT and CSCT images.The interplay between XFCT and CSCT was analyzed,and the contrast-to-noise ratio(CNR)of the reconstruction was improved by correcting for the mutual influence between the two imaging modalities.Compared with K-edge subtraction imaging,XFCT exhibits a CNR advantage for the phantom.Conclusion Simultaneous XFCT and CSCT can be realized by using linearly polarized X-rays.The synergy between the two imaging modalities would have an important application in cancer radiation therapy.

Noninvasive beam diagnosis based on the TM_(010)mode

A resonant cavity based on the TM_(010)mode is an effective tool for noninvasive beam characterization. This technique has the advantages of a high signal-to-noise ratio, compact structure, and is related to multiple parameters compared with other beam monitors. In this study, high-precision measurements of the bunch charge, arrival time, bunch length, and energy parameters based on the TM_(010)mode are discussed. A cavity beam arrival time monitor(BAM) utilizing a phase cavity has been widely used in many facilities. Regarding bunch-length measurements, the influence of the beam energy, beam offset,and longitudinal spectrum on the TM_(010)mode are carefully considered to reduce errors, and the theoretical resolution of two cavities with different frequencies is analyzed. Owing to the dependence of the beam velocity of the beam loss factor, this method can also be used for the detection low beam energy using two cavities with the same frequency but different cavity lengths. A set of three cavities with different lengths and frequencies of 1.902 and 11.424 GHz is presented for measuring the four aforementioned parameters.

Tectonic evolution and accumulation characteristics of Carboniferous shale gas in Yadu-Ziyun-Luodian aulacogen, Guizhou Province, South China

The Yadu-Ziyun-Luodian aulacogen(YZLA) developed into being NW-trending in the Late Paleozoic,and was considered as an important passive continental margin aulacogen in Guizhou Province, South China. This tectonic zone is considered a large intracontinental thrust-slip tectonic unit, which has undergone a long period of development. It was ultimately determined in the Yanshanian, where the typical Upper Paleozoic marine shales were deposited. In 2021, Well QSD-1 was deployed in the Liupanshui area at the northwest margin of the aulacogen, and obtained a daily shale gas flow of 11011 m3in the Carboniferous Dawuba Formation. It thus achieved a breakthrough in the invesgation of shale gas in the Lower Carboniferous in South China, revealing relatively good gas-bearing properties and broad exploration prospects of the aulacogen. Being different from the Lower Paleozoic strata in the Sichuan Basin and the Yichang area of the Middle Yangtze, the development of the Carboniferous Dawuba Formation in the aulacogen exhibits the following characteristics:(1) The Lower Carboniferous shale is thick and widely distributed, with interbedded shale and marlstone of virous thickness;(2) The total organic carbon(TOC) content of the shale in the Dawuba Formation ranges from 1% to 5%, with an average of 2%, and the thermal maturity of organic matter(Ro) varies from 1% to 4%, with an average of2.5%, indicating good hydrocarbon generation capacity;(3) The main shale in the aulacogen was formed during the fault subsidence stage from the Middle Devonian to the Early Permian. Although the strong compression and deformation during the late Indosinian-Himalayan played a certain role in destroying the formed shale gas reservoirs, comparative analysis suggests that the area covered by the current Triassic strata has a low degree of destruction. It therefore provides good conditions for shale gas preservation,which can be regarded as a favorable area for the next exploration.

Continuous-wave optical enhancement cavity with 30-kW average power

Optical enhancement cavity(OEC)is a powerful tool for fundamental research and diagnostics.In this paper,the progress of a continuous-wave OEC to realize of megawatt cavity for a novel light source based on a steady-state microbunching(SSMB)mechanism,is reported.After efficiently suppressing all external noise and optimizing the alignment,mode-matching,and polarization matching,stable and long-term locking is achieved with the help of two feedback loops.The modal instability phenomenon caused by the surface thermoelastic deformation is observed.A pair of D-shape mirrors are utilized to remove the high-order modes.Finally,an intra-cavity average power of 30 kW is reached.

sTREM-1、Presepsin对儿童脓毒症诊断和预后评估的价值

目的探讨可溶性髓样细胞触发受体1(sTREM-1)、Presepsin对儿童脓毒症诊断和预后评估的价值。方法选取青海大学附属医院2019年1月—2020年12月收治的103例脓毒症患儿为脓毒症组,根据病情严重程度分为一般脓毒症组(n=48)、严重脓毒症组(n=34)及脓毒症休克组(n=21)。选取同期收治的50例普通感染患儿为感染组,40例健康体检儿童为对照组。比较各组血浆sTREM-1、Presepsin水平;采用Spearman法分析脓毒症患儿血浆sTREM-1、Presepsin水平与序贯器官衰竭(SOFA)评分的相关性;记录脓毒症患儿28 d后的预后情况,采用多因素Logistics回归分析脓毒症患儿预后不良的影响因素;绘制受试者工作特征(ROC)曲线预测血浆sTREM-1、Presepsin对脓毒症诊断和预后评估的价值。结果脓毒症组血浆sTREM-1、Presepsin水平高于感染组和对照组,感染组高于对照组(P<0.05)。脓毒症休克组血浆sTREM-1、Presepsin水平高于一般脓毒症组和严重脓毒症组,严重脓毒症组高于一般脓毒症组(P<0.05)。Spearman相关性分析结果显示,脓毒症组血浆sTREM-1、Presepsin水平与SOFA评分呈正相关(rs=0.434和0.412,P=0.000和0.001)。脓毒症患儿死亡28例,儿科重症监护病房时间、机械通气时间、SOFA评分、sTREM-1、Presepsin为脓毒症患儿预后不良的独立危险因素(P<0.05)。ROC曲线显示,sTREM-1+Presepsin诊断脓毒症的敏感性为82.52%(95%CI:0.738,0.893),特异性为88.00%(95%CI:0.757,0.956);sTREM-1+Presepsin评估脓毒症患儿预后不良的敏感性为81.09%(95%CI:0.713,0.932),特异性为89.19%(95%CI:0.734,0.914)。结论脓毒症患儿血浆sTREM-1、Presepsin水平明显升高,与脓毒症发生、发展相关,可作为脓毒症诊断与预后评估指标,联合预测价值更高。

Beam and image experiment of beam deflection electron gun for distributed X-ray sources

Distributed X-ray sources comprise a single vacuum chamber containing multiple X-ray sources that are triggered and emit X-rays at a specific time and location. This process facilitates an application for innovative system concepts in X-ray and computer tomography. This paper proposes a novel electron beam focusing, shaping,and deflection electron gun for distributed X-ray sources.The electron gun uses a dispenser cathode as an electron emitter, a mesh grid to control emission current, and two electrostatic lenses for beam shaping, focusing, and deflection. Novel focusing and deflecting electrodes were designed to increase the number of focal spots in the distributed source. Two identical half-rectangle opening electrodes are controlled by adjusting the potential of the two electrodes to control the electron beam trajectory, and then, multifocal spots are obtained on the anode target. The electron gun can increase the spatial density of the distributed X-ray sources, thereby improving the image quality. The beam experimental results show that the focal spot sizes of the deflected(deflected amplitude 10.5 mm)and non-deflected electron beams at full width at half maximum are 0.80 mm 90.50 mm and 0.55 mm 90.40 mm, respectively(anode voltage 160 kV; beam current 30 mA). The imaging experimental results demonstrate the excellent spatial resolution and time resolution of an imaging system built with the sources, which has an excellent imaging effect on a field-programmable gate array chip and a rotating metal disk.

Design and test of an RF acceleration system loaded with magnetic alloy for the proton synchrotron of the Xi'an Proton Application Facility

The Xi'an Proton Application Facility(XiPAF)is a facility dedicated to the experimental simulation of the space radiation environment.The facility uses a compact synchrotron as its final-stage accelerator.The synchrotron can accelerate a proton beam from 7 to 230 MeV.Physical design results show that the radio frequency(RF) acceleration system should work in the frequency range of 1—6 MHz and provide a maximum voltage of >800 V.To dilute the strong space charge effect during the injection period,we also aim to achieve multiharmonic acceleration.A compact RF acceleration system loaded with magnetic alloy cores has been designed and developed to fulfill these requirements.The preliminary test results show that the system can work normally with a gap voltage of 800 V.With a further RF power upgrade,the voltage can be improved to >1:2 kV.

Beam dynamics optimization of very-high-frequency gun photoinjector

Very-high-frequency(VHF)gun photoinjectors,capable of producing high-brightness and high-repetitionrate electron bunches,are some of the best electron sources for driving MHz-class repetition-rate free-electron lasers.In this study,the beam dynamics optimization of a VHF gun photoinjector for Shanghai HIgh Repetition Rate X-ray Free Electron Laser and Extreme Light Facility(SHINE)is systematically demonstrated using a genetic algorithm.Through the inclusion of the solenoid geometry as an optimization variable into the genetic algorithm,the optimum projected normalized emittance for 100 pC bunches with bunch length of 1 mm rms is reduced to 0.1 mm mrad for 100%of the particles and 0.075 mm mrad for 95%of the particles,proving that sub-100 nm emittance can be achieved in the SHINE injector using a single-cell Tsinghua University(THU)VHF gun.This emittance fulfills the requirements not only of SHINE and Linac Coherent Light Source(LCLS)-II but also of LCLS-II-High Energy(LCLS-II-HE).We demonstrate that the optimal emittance in the VHF gun injector is reduced via the optimization of the solenoid geometry,thereby reducing solenoid spherical aberration.Through the inclusion of high-order(H.O.)energy spread among the optimization objectives,the H.O.energy spread can be reduced by a factor of nearly six using a high-harmonic cavity despite a 38%emittance growth.Finally,the beam dynamics in the SHINE main accelerator show that reducing the H.O.energy spread in the injector is of great significance to improving compression efficiency and reducing bunch current spike.

Prostate artery embolization on lower urinary tract symptoms related to benign prostatic hyperplasia: A systematic review and metaanalysis

BACKGROUND Prostate artery embolization(PAE)is a promising minimally invasive therapy that improves lower urinary tract symptoms(LUTS)related to benign prostatic hyperplasia(BPH).Transurethral resection of the prostate(TURP)is the gold standard therapy for LUTS/BPH.AIM To evaluate the efficacy and safety of PAE vs TURP on LUTS related to BPH.METHODS A literature review was performed to identify all published articles on PAE vs TURP for LUTS/BPH.Sources included PubMed,Embase,Cochrane library databases,and Chinese databases before June 2022.A systematic review and meta-analysis were conducted.Outcome measurements were combined by calculating the mean difference with a 95%confidence interval.Statistical analysis was carried out using Review Manager 5.3.RESULTS Eleven studies involving 1070 participants were included.Compared with the TURP group,the PAE group had a similar effect on the International Index of Erectile Function(IPSS)score,Peak urinary flow rate(Qmax),postvoid residual volume(PVR),Prostate volume(PV),prostatic specific antigen(PSA),The International Index of Erectile Function short form(IIEF-5)scores,and erectile dysfunction during 24 mo follow-up.Lower quality of life(QoL)score,lower rate of retrograde ejaculation and shorter hospital stay in the PAE group.There was no participant death in either group.A higher proportion of haematuria,urinary incontinence and urinary stricture was identified in the TURP group.CONCLUSION PAE may be an appropriate option for elderly patients,patients who are not candidates for surgery,and patients who do not want to risk the potential adverse effects of TURP.Studies with large cases and long follow-up time are needed to validate results.

Geochemical characteristics and sedimentary environment of the Middle Devonian organic-rich shales in the Northwest of Guizhong Depression, Southwest China

In order to figure out the redox conditions and paleo-sedimentary environment of the Middle Devonian shales in the northwest of Guizhong Depression,the trace element analysis was conducted on the Middle Devonian cores(320.35–938.50 m)of the typical shale gas investigation well(GY-1)at a 1.50 m sampling interval through X-ray fluorescence spectroscopy(XRF)and inductively coupled plasma mass spectrometry(ICP-MS).According to the test result,the average values of V/(V+Ni),V/Cr and Ni/Co in Nabiao formation(Fm.)are larger than 0.67,4.65 and 7.71 respectively,and Nabiao Fm.is rich in biological assemblages such as tabasheer,ammonite,etc.These evidences indicate the rising sea level rose relatively in the sedimentation period of Nabiao Fm.and a deepwater shelf environment,which was favorable for the preservation of organic matters.The V/(V+Ni),V/Cr and Ni/Co in Luofu Fm.and Tangting Fm.are 0.38–0.65,0.73–4.10 and 3.70–6.72 respectively,indicating that the sea level dropped relatively in their sedimentation period,during which the water bodies became shallow,and the sedimentary environment was a weak oxidizing shallow water shelf environment.In addition,the variation of TOC has a high correlation with the enrichment degree of Ba element,indicating the favorable conditions for the enrichment and preservation of organic matters under an oxygen-deficient environment.Moreover,according to the identification of trace element indexes,the northwest of Guizhong Depression experienced the sedimentary cycle of relative rise to relative fall of sea level from bottom to top in the Middle Devonian sedimentation period.The relative sea level rose to the highest in the sedimentation period of Nabiao Fm.,in which the organic-rich shales with stable thickness and high organic content were deposited.Hence,the Nabiao Fm.could be regarded as the favorable exploration target interval in this area.

Laser-RF synchronization based on digital phase detector

Laser oscillator synchronization with RF reference signal is ultra-important for a modern light source based on the accelerator.For Tsinghua Thomson scattering X-ray source,we have synchronized the mode-locked laser oscillator to RF reference signal with 48.2 fs RMS relative jitter.Both fundamental and harmonic signals derived from photo diode detection are used for laser-RF synchronization in our scheme.The fundamental signal is for coarse laser-RF synchronization and multiple laser oscillator synchronization.The harmonic signal is for high precise phase locking.The digital phase detector is implemented in the synchronization scheme for less noise,replacing the mixing to DC phase detection scheme.The digital processing algorithm for synchronization is commonly used in low-level RF control field.In order to test the phase locking loop logic without damaging the real laser oscillator,a laser oscillator emulator was developed for phase locking.This paper will report the laser-RF synchronization scheme and its performance.The laser oscillator emulator system will also be introduced here.

Beam position monitors as precise phase pickups for beam energy measurement at the Compact Pulsed Hadron Source

The 13-MeV proton linac of the Compact Pulsed Hadron Source(CPHS) at Tsinghua University, China,is composed of a 50-keV electron cyclotron resonance proton source, a 3-MeV four-vane-type radio-frequency quadrupole(RFQ) accelerator, and a drift tube linac(DTL). Precise measurement of the beam energies at the exit of the RFQ and the DTL is critical for DTL commissioning. Two button-type beam position monitors(BPMs) installed downstream of the RFQ are used to perform the measurement using a time-of-flight method. The effects of several factors on phase measurement accuracy are analyzed. The phase measurement accuracy of the BPMs at CPHS is better than ± 1.03° at 325 MHz after corrections,corresponding to an energy measurement error of± 0.07%. The beam energy measured at the exit of the RFQ is 2.994 ± 0.0022 MeV,which is consistent with the design value.

Successful treatment of pyoderma gangrenosum with concomitant immunoglobulin A nephropathy: A case report and review of literature

Pyoderma gangrenosum(PG)is an uncommon ulcerative cutaneous condition of an unknown etiology and is often associated with immune diseases.However,PG rarely shows visceral involvement,especially in the kidney.A 20-year-old female presented with pedal edema and skin ulceration of both lower limbs.The skin lesion began as an erythematous plaque and then became a blister.She also complained of abdominal distension and a decreasing urine volume.Laboratory data showed high proteinuria,hypoalbuminemia and hyperlipidemia.Her skin and kidney were biopsied.The pathological results indicated PG and immunoglobulin A(IgA)nephropathy.The patient was finally cured with prednisolone in combination with cyclosporine A(CsA).

Evaluation method of coal rank based on X-ray diffraction analysis an example from SE Qinshui Basin

Based on analysis on X-ray diffraction, the metamorphic grade of coal in southeast Qinshui Basin was discussed, and a precise evaluation of coal rank through XRD analysis was made, in addition, the correlation of coal rank and vitrinite reflectance （Ro） was compared. XRD spectra of coal shows （002）-band and γ-band, and based on fitting calculation and multi-peak separation methods, the values of 2θ002 and 2θγ can be obtained, as well as corresponding intensities I002 and Iγ, consequently the coal rank can be quantized as the ratio of I002 and Iγ, that is coal rank=I002/Iγ. The research shows that the values of θ002 and θγ increase with the metamorphic grade, and a very good linear positive correlation exists between calculated Coal Rank and Ro.

Effects of ulinastatin combined with thymopentin on cellular immunity, humoral immunity and stress response in severe pneumonia

Objective:To explore the effects of ulinastatin combined with thymopentin on cellular immunity, humoral immunity and stress response in severe pneumonia.Methods: A total of 102 cases of severe pneumonia treated in our hospital from February 2016 to November 2017 were collected as subjects and randomly divided into the control group (n=51) and the observation group (n=51), the two groups were treated with routine symptomatic treatment. The control group was treated with the ulinastatin on the basis of routine treatment, the observation group was treated with thymopentin on the basis of the control group. The changes of cellular immunity, humoral immunity, stress response and liver function in the two groups were compared.Results: Before treatment, there was no significant difference in the levels of CD4+, CD8+, CD4+/CD8+, IgA, IgM, IgG, SOD, MDA, T-AOC, AKP, TB and ALT between the two groups (P>0.05). After treatment, the two groups of CD4+ and CD4+ /CD8+ were significantly increased (P<0.05), CD8+ was significantly lower than before treatment (P<0.05), and CD4+ and CD4+ /CD8+ in the observation group were significantly increased compared with the control group (P<0.05), CD8+was significantly lower than the control group (P<0.05);the two groups of IgA, IgM and IgG were significantly increased compared with those before treatment (P<0.05), and the IgA, IgM and IgG in the observation group were significantly higher than those in the control group (P<0.05);two groups of SOD and T-AOC were significantly higher than before treatment (P<0.05), while MDA was significantly lower than before treatment (P<0.05), and SOD and T-AOC in the observation group were significantly increased (P<0.05), and MDA was significantly lower than that of the control group (P<0.05);two groups of AKP, TB and ALT were significantly lower than those before treatment (P<0.05), and the AKP, TB and ALT in the observation group were significantly lower than those in the control group (P<0.05).Conclusions: ulinastatin combined with thymopentin in patients with severe pneumonia can effectively enhance the cellular immunity and humoral immune function, reduce oxidative stress damage and protect the liver function, which has clinical significance.

Macrophage exosomes transfer angiotensin Ⅱ type 1 receptor to lung fibroblasts mediating bleomycin-induced pulmonary fibrosis

Background:Macrophages are involved in the pathogenesis of idiopathic pulmonary fibrosis,partially by activating lung fibroblasts.However,how macrophages communicate with lung fibroblasts is largely unexplored.Exosomes can mediate intercellular communication,whereas its role in lung fibrogenesis is unclear.Here we aim to investigate whether exosomes can mediate the crosstalk between macrophages and lung fibroblasts and subsequently induce fibrosis.Methods:In vivo,bleomycin(BLM)-induced lung fibrosis model was established and macrophages infiltration was examined.The effects of GW4869,an exosomes inhibitor,on lung fibrosis were assessed.Moreover,macrophage exosomes were injected into mice to observe its pro-fibrotic effects.In vitro,exosomes derived from angiotensin Ⅱ(Ang Ⅱ)-stimulated macrophages were collected.Then,lung fibroblasts were treated with the exosomes.Twenty-four hours later,protein levels ofα-collagen I,angiotensin Ⅱ type 1 receptor(AT1R),transforming growth factor-β(TGF-β),and phospho-Smad2/3(p-Smad2/3)in lung fibroblasts were examined.The Student's t test or analysis of variance were used for statistical analysis.Results:In vivo,BLM-treated mice showed enhanced infiltration of macrophages,increased fibrotic alterations,and higher levels of Ang Ⅱ and AT1R.GW4869 attenuated BLM-induced pulmonary fibrosis.Mice with exosomes injection showed fibrotic features with higher levels of Ang Ⅱ and AT1R,which was reversed by irbesartan.In vitro,we found that macrophages secreted a great number of exosomes.The exosomes were taken by fibroblasts and resulted in higher levels of AT1R(0.22±0.02 vs.0.07±0.02,t=8.66,P=0.001),TGF-β(0.54±0.05 vs.0.09±0.06,t=10.00,P<0.001),p-Smad2/3(0.58±0.06 vs.0.07±0.03,t=12.86,P<0.001)andα-collagen I(0.27±0.02 vs.0.16±0.01,t=7.01,P=0.002),and increased Ang Ⅱ secretion(62.27±7.32 vs.9.56±1.68,t=12.16,P<0.001).Interestingly,Ang Ⅱ increased the number of macrophage exosomes,and the protein levels of Alix(1.45±0.15 vs.1.00±0.10,t=4.32,P=0.012),AT1R(4.05±0.64 vs.1.00±0.09,t=8.17,P=0.001),and glyceraldehyde-3-phosphate dehydrogenase(2.13±0.36 vs.1.00±0.10,t=5.28,P=0.006)were increased in exosomes secreted by the same number of macrophages,indicating a positive loop between Ang Ⅱ and exosomes production.Conclusions:Exosomes mediate intercellular communication between macrophages and fibroblasts plays an important role in BLM-induced pulmonary fibrosis.

Novel and functional DNA sequence variants within the GATA5 gene promoter in ventricular septal defects

Background:Congenital heart disease(CHD)is the most common human birth defect.Genetic causes for CHD remain largely unknown.GATA transcription factor 5(GATA 5)is an essential regulator for the heart development.Mutations in the GATA5 gene have been reported in patients with a variety of CHD.Since misregulation of gene expression have been associated with human diseases,we speculated that changed levels of cardiac transcription factors,GATA5,may mediate the development of CHD.Methods:In this study,GATA5 gene promoter was genetically and functionally analyzed in large cohorts of patients with ventricular septal defect(VSD)(n=343)and ethnic-matched healthy controls(n=348).Results:Two novel and heterozygous DNA sequence variants(DSVs),g.61051165A>G and g.61051463delC,were identified in three VSD patients,but not in the controls.In cultured cardiomyocytes,GATA5 gene promoter activities were significantly decreased by DSV g.61051165A>G and increased by DSV g.61051463delC.Moreover,fathers of the VSD patients carrying the same DSVs had reduced diastolic function of left ventricles.Three SNPs,g.61051279C>T(rs77067995),g.61051327A>C(rs145936691)and g.61051373G>A(rs80197101),and one novel heterozygous DSV,g.61051227C>T,were found in both VSD patients and controls with similar frequencies.Conclusion:Our data suggested that the DSVs in the GATA5 gene promoter may increase the susceptibility to the development of VSD as a risk factor.