Evaluation of recurrence in gastric carcinoma: Comparison of contrast-enhanced computed tomography and positron emission tomography/computed tomography

AIM To compare the value of contrast-enhanced abdominal computed tomography(CT) and fluorodeoxyglucose(FDG) positron emission tomography/computed tomography(PET/CT) for detecting gastric carcinoma recurrence.METHODS We retrospectively examined data from 2475 patients who underwent both contrast-enhanced abdominal CT and FDG PET/CT for the surveillance of gastric carcinoma curative resection. Patients had an interval of less than 1 mo between their CT and PET/CT scans. Sixty patients who had recurrence were enrolled. Among 1896 patients who did not have recurrence, 60 were selected by simple random sampling. All CT and PET/CT images were reviewed retrospectively by two reviewers blinded to all clinical and pathologic information except curative resection due to gastric carcinoma. RESULTS The pathological stage of the recurrence group was statistically significantly higher than that of the control group(P < 0.001). In the 60 patients who had recurrence, there were 79 recurrent lesions. Fortyfour patients had only one location of recurrence, 13 patients had two locations, and 3 patients had three. In the detection of patient-based overall recurrence, no statistically significant differences existed between the two modalities(P = 0.096). However, for peritoneal carcinomatosis, CT had a statistically significantly higher sensitivity compared to PET/CT(96% vs 50%, P = 0.001). Adenocarcinoma was the most common type of gastric carcinoma. On the pathology-based analysis, CT also had a statistically significantly higher sensitivity compared to PET/CT(98% vs 80%, P = 0.035).CONCLUSION Contrast-enhanced CT was superior to PET/CT in the detection of peritoneal carcinomatosis and pathologic type of adenocarcinoma.

Automatically positioning microseismic sources in mining by the stereo tomographic method using full wavefields

For microseisimic monitoring it is difficult to determine wave modes and their propagation velocity. In this paper, we propose a new method for automatically inverting in real time the source characteristics of microseismic events in mine engineering without wave mode identification and velocities. Based on the wave equation in a spherical coordinate system, we derive a tomographic imaging equation and formulate a scanning parameter selection criterion by which the microseisimic event maximum energy and corresponding parameters can be determined. By determining the maximum energy positions inside a given risk district, we can indentify microseismic events inside or outside the risk districts. The synthetic and field examples demonstrate that the proposed tomographic imaging method can automatically position microseismic events by only knowing the risk district dimensions and range of velocities without identifying the wavefield modes and accurate velocities. Therefore, the new method utilizes the full wavefields to automatically monitor microseismic events.

Granulocyte colony-stimulating factor-producing squamous cell carcinoma of the tongue exhibiting characteristic fluorine-18 deoxyglucose accumulation on positron emission tomography–computed tomography: A case report

BACKGROUND Granulocyte colony-stimulating factor(G-CSF)is a cytokine produced in inflammatory environments that induces differentiation and proliferation of neutrophils in bone marrow.We report a rare case of aggressive G-CSFproducing squamous cell carcinoma of the tongue exhibiting fluorine-18 deoxyglucose(FDG)accumulation in primary lesion,metastatic lymph nodes,spleen,and bone marrow on positron emission tomography–computed tomography(PET/CT).CASE SUMMARY We report a 58-year-old female with a rapid enlarged lingual mass with partial necrosis.Blood test results from the initial examination revealed a leukocyte count of 21380/μL.On PET/CT,extensive FDG accumulation was observed in the tongue and bilateral cervical lymph nodes,with elevated FDG accumulation in the spleen and bone marrow although no distant metastases were observed.We performed partial glossectomy and bilateral neck dissection.Immunohistochemical staining with G-CSF antibodies on biopsy specimen and resected samples revealed that both specimens were G-CSF positive.This is a rare case of G-CSF producing tongue carcinoma with elevated FDG accumulation in the spleen and bone marrow.CONCLUSION In patients with the tongue cancer and hyperleukocytosis,where FDG accumulations in the spleen and bone marrow are observed using PET/CT and when these accumulations are not caused by metastasis,G-CSF-producing tumors,with associated poor prognosis,should be considered.

Effective Solution Algorithm for Tomographic Inversion of Volume Emission Rate from Satellite-based Limb Measurement

The volume emission rate (VER) of airglow can be used to investigate atmospheric processes. Satellite-based limb measurement of atmosphere is able to obtain the VER profile of airglow with high vertical resolution. However, the traditional one-dimensional retrieval techniques for VER inversion fail to retrieve horizontal structure of VER profile. Thus, the tomographic technique based on the maximum probability is applied to retrieving two-dimensional VER profile of airglow from infrared limb measurement. This technique could process the observed data with low signal-to-noise ratio caused by the observation angle of less than 180° due to the solid nature of the Earth. For saving the processing time and improving the computing speed of VER inversion, serial tables for storing the large sparse matrix for radiance simulation and a large dataset during iterative estimate of VER are presented. The index and weighting factor of line of sight (LOS) through each grid are saved in initial estimate to avoid being computed repeatedly. Furthermore, the product of observed radiance and corresponding weighting factor obtained in initial iteration is stored as weighted observed radiance for the iterative calculation subsequently. Based on the improved algorithm, the VER of airglow is inversed through the tomographic technique. The full width of half maximum (FWHM) of error is 1.78% and the offset of the peak percentage error is 0.22% after 40 iterations for final VER. Comparison of assumed and retrieved VER profiles suggests that VER can be retrieved with a bias of 15% between 10 km and 90 km above the LayerMin (6384 km from the Earth center), and with a bias of 8% for altitude from 30 km to 60 km with vertical resolution of 1 km after 40 iterations. After improvements, the computation speed of VER inversion for once can be improved by 29.6 times for 700 images of 1/3 orbit, and accordingly, the processing time will be reduced from 3 hours and 11 minutes to only 6 minutes. In conclusion, the improvements to tomographic inversion of VER of airglow proposed in this paper are effective and significant.

Study of image reconstruction using dynamic grids in tomographic gamma scanning

In this paper, a new image reconstruction algorithm employing dynamic grids technique is proposed for tomographic gamma scanning. The key feature of the algorithm is the use of adaptive grid refinement in areas that indicate large values. Simulation results show that the application of dynamic grids has a good performance in emission reconstruction with a distinct advantage in the accurate positioning of the 'hot spots' and reducing the number of grids, but doesn't achieve a tangible improvement in transmission reconstruction.

The establishment of crystal position look-up table for positron emission tomography with block detectors

A method has been developed to establish the crystal position look-up table for positron emission tomography with block detectors. It is based on the principle that the counts in crystal position histogram obey the Gaussian mixture model (GMM). This method has taken full consideration of the characteristics of the GMM and the detector itself. The experimental results have proved that it is simple, reliable, and universal.

Effects of Global Value Chain Position on the Carbon Emissions of Manufacturing Industry in China: An Empirical Study Based on the STIRPAT Model

Based on the input-output data from the World Input-Output Database( WIOD),the global value chain( GVC) position of China's manufacturing industry from 2003 to 2014 was calculated,and the relationship between the carbon emissions and global value chain position of China's manufacturing industry was studied based on the improved STIRPAT model. The results show that the improvement of global value chain position could significantly reduce the carbon emissions of China's manufacturing industry. In addition,foreign investment and energy structure hindered the low-carbon development of China's manufacturing industry. The effects of population size and research intensity on the carbon emissions of manufacturing industry were not significant. In the process of participating in the global value chain,China's manufacturing industry should effectively reduce carbon emissions by strengthening environmental regulation,optimizing energy structure and improving production technology.

The Effect of Catena Position on Greenhouse Gas Emissions from Dambo Located Termite (<i>Odontotermes transvaalensis</i>) Mounds from Central Zimbabwe

Methane (CH4), carbon dioxide (CO2) and nitrous oxide (N2)O) are greenhouse gases (GHGs) which cause global warming. Natural sources of GHGs include wetlands and termites. Previous studies have quantified GHG emissions from upland termites and no study has reported GHG emissions from seasonal wetlands (dambo) located termite mounds. The objective of this study was to evaluate the effect of dambo catena position on termite mound distribution and GHG emissions. It was hypothesized that mound density and GHG emissions from Odontotermes transvaalensis mounds, vary with catena position. The evaluated catena positions were margin, mid-slope, lower slope and bottom. Mound density was significantly lower in the bottom when compared to the other catena positions. The mean GHG fluxes were 88 μg m2 hr-1, 0.78 mg m2 hr-1 and 1361 mg m2 hr-1 for N2) O, CH4 and CO2 respectively. Fluxes varied with catena position and were 0.48, 0.72, 1.35 and 0.79 mg m-2 hr-1 for CH4 , and 1173.7, 1440.7, 1798.7 and 922.8 mg m-2 hr-1 for CO2 in the margin, mid-slope, lower slope and the bottom catena position respectively. For N2) O, there were no significant differences between catena positions. It was concluded that dambo located Odontotermes transvaalensis termite mounds are an important source of GHGs, and emissions varied with catena position for CO2 and CH4.

Advancements and challenges in neuroimaging for the diagnosis of intracranial aneurysms:Addressing false positive diagnoses and emerging techniques

Despite advancements in neuroimaging,false positive diagnoses of intracranial aneurysms remain a significant concern.This article examines the causes,prevalence,and implications of such false-positive diagnoses.We discuss how conditions like arterial occlusion with vascular stump formation and infundibular widening can mimic aneurysms,particularly in the anterior circulation.The article compares various imaging modalities,including computer tomography angiogram,magnetic resonance imaging/angiography,and digital subtraction angiogram,highlighting their strengths and limitations.We emphasize the im-portance of accurate differentiation to avoid unnecessary surgical interventions.The potential of emerging technologies,such as high-resolution vessel wall ima-ging and deep neural networks for automated detection,is explored as promising avenues for improving diagnostic accuracy.This manuscript underscores the need for continued research and clinical vigilance in the diagnosis of intracranial aneurysms.

Effects of sonic speed on location accuracy of acoustic emission source in rocks

To quantitatively study the location errors induced by deviation of sonic speed, the line and plane location tests were carried out. A broken pencil was simulated as acoustic emission source in the rocks. The line and plane location tests were carried out in the granite rod using two sensors and the cube of marble using four sensors, respectively. To compare the position accuracy between line and plane positions, the line poison test was also carried out on the marble surface. The results show that for line positioning, the maximum error of absolute distance is about 0.8 cm. With the speed difference of 200 m/s, the average value of absolute difference from the position error is about 0.4 cm. For the plane positioning, in the case of the sensor array of 30 cm, the absolute positioning distance is up to 8.7 cm. It can be seen that the sonic speed seriously impacts on the plane positioning accuracy. The plane positioning error is lager than the line positioning error, which means that when the line position can satisfy the need in practical engineering, it is better to use the line position instead of the plane location. The plane positioning error with the diagonal speed is the minimum one.

Improved Study on Position Measurement System for Linear Motor Applied in Electromagnetic Launch System

The linear motor applied in electromagnetic emission system uses a closed loop position control strategy,which needs a set of position measurement system with high reliability,high resolution and integration to achieve real-time acquisition and analysis of position signals.The existing position controller is based on the simple logic chip design without memory function,and does not have the storage analysis and preprocessing function to position signals.Therefore,the system has insufficient scalability,low integration and reliability.Aiming at the improvement of the existing position measurement system,an intelligent position measurement system integrating the functions of position signals acquisition,processing and uploading,data storage and analysis is proposed in this paper,and its working principle and system composition are discussed in detail.The position,speed and acceleration obtained on the electromagnetic emission platform are in good agreement with the expected value of the system.As results,the feasibility and accuracy of the improved integrated intelligent position measurement system are verified,and the control performance of the system is also satisfied well,which can be good guidance and reference for subsequent engineering practice.

Effect of Electron and/or Ion Nonthermality on Dust Acoustic Wave Propagation in a Complex Plasma in Presence of Positively Charged Dust Grains Generated by Secondary Electron Emission Process

In this paper we have developed a model to study the role of both electron and ion nonthermalities on dust acoustic wave propagation in a complex plasma in presence of positively charged dust grains. Secondary electron emission from dust grains has been considered as the source of positive dust charging. As secondary emission current depends on the flux of primary electrons, nonthermality of primary electrons changes the expression of secondary emission current from that of earlier work where primary electrons were thermal. Expression of nonthermal electron current flowing to the positively charged dust grains and consequently the expression of secondary electron current flowing out of the dust grains have been first time calculated in this paper, whereas the expression for nonthermal ion current flowing to the positively charged dust grains is present in existing literature. Dispersion relation of dust acoustic wave has been derived. From this dispersion relation real frequency and growth rate of the wave have been calculated. Results have been plotted for different strength of nonthermalities of electrons and ions.

点火位置对X型转子发动机燃烧过程的影响

为探究X型转子发动机独特燃烧室内复杂湍流场与点火位置的耦合作用对混合气燃烧过程的影响,建立了X型转子发动机的三维计算流体动力学模型,并与试验结果进行对比验证,数值研究了不同点火位置下X型转子发动机缸内燃烧过程,揭示了点火位置对火焰传播、燃烧特性及污染物形成的影响规律。结果表明,在压缩末期,X型转子发动机燃烧室内形成了包括涡流和单向流的复杂湍流场,这与点火位置的耦合作用显著影响火焰传播过程。为了获得较高火焰传播速度,点火位置不宜布置在漩涡区处。点火位置位于凹坑中部时,可以充分利用四周空间和涡团与单向流场过渡处形成的较高速度场加速火焰传播,从而提前燃烧重心,增加放热速率,而且峰值压力提高了25%,指示热效率超过30%;同时其也具有较低的HC和CO排放量;但是由于其缸内峰值温度较大,导致NO排放量增加。

双向机制下企业自愿碳减排的三方博弈模拟

工业企业碳减排对平衡环境保护和经济发展尤为重要。基于政府和消费者双向机制探究企业自愿碳减排的影响因素,根据政府正向激励机制和消费者反向倒逼机制构建政府、企业和消费者三方演化博弈模型,分析了各参与方策略选择的演化稳定性,从系统动力学角度探讨三方主体策略选择不同时各个参数对企业自愿碳减排的影响机制,进一步分析了三方博弈系统中均衡点的稳定性。结果表明:企业选择自愿减排策略的概率与消费者低碳消费概率和政府非物质激励带给企业的收益额、减排成本补贴率、政府奖金、企业碳披露损失额等参数呈正相关;与企业的低碳营销费用、绿色积分价值、消费污染等参数呈负相关。最后,利用MATLAB 2016a进行数值仿真,验证了以上结论,并结合实际提出相关建议。

基于临床试验验证Insight NM/CT Pro SPECT/CT安全性与有效性

目的 通过临床验证获得临床影像质量可接受率、设备常用功能、机器使用便捷性、整机稳定性满意度与安全性评价,对Insight NM/CT Pro SPECT/CT成像系统临床应用中的安全性与有效性进行验证。资料与方法 前瞻性选取内蒙古医科大学附属医院2022年7—10月自愿参与试验的受试者79例,使用Insight NM/CT Pro SPECT/CT分别进行内分泌、循环、骨骼、呼吸、泌尿多系统显像,对图像质量进行有效性评价,并评价机器运行情况与安全性。结果 79例患者影像质量评价:平面显像36例中可接受者35例;断层显像43例中可接受者42例,可接受率分别为97.22%、97.67%,95%CI下限分别为85.47%、87.71%,均高于目标值(83.00%)。操作人员对79例患者进行显像操作时,设备常用功能、设备使用便捷性、整机稳定性评价均满意,满意率为100%,未发生不良事件。结论 Insight NM/CT Pro SPECT/CT有效性可满足临床应用要求,图像组织结构显示清楚,设备常用功能齐备,系统稳定,安全性较高。

面向欧盟《电池和废电池法规》动力电池碳足迹的减排路径与情景

2023年8月17日,欧盟《电池和废电池法规》(简称新《电池法》)在欧盟正式生效,并引入电池护照概念。根据该法规,从2025年2月18日起,动力电池需提供电池的碳足迹信息,以突破欧盟贸易壁垒,促进国内动力电池的出口。本文以NCM三元5系电池为研究对象,对动力电池的碳足迹进行了梳理与分析,同时按照欧盟新《电池法》的要求,分析了在不同情景模式下电池的碳足迹减排情况。结果发现:①动力电池的碳排放减排关键在于正极材料,其碳排放占电芯原材料总碳排放的58%,其中正极前驱体在正极材料碳排放中的占比高达85%,其次是能耗碳排放,占电芯总碳排放的20%;②在使用可再生能源的情况下,5系电芯产品的碳足迹排放最低可以减少2.73%,最高可减少13.69%,其次仅使用正极再生材料减排,则5系电芯产品的碳足迹排放最低可减少1.81%,最高可减少7.86%;③在正极再生材料与可再生能源结合使用的情况下,5系电芯产品的碳足迹排放最低可减少4.55%,最高可减少21.55%。

Time-resolved characteristics of a nanosecond pulsed multi-hollow needle plate packed bed dielectric barrier discharge

In this paper,self-designed multi-hollow needle electrodes are used as a high-voltage electrode in a packed bed dielectric barrier discharge reactor to facilitate fast gas flow through the active discharge area and achieve large-volume stable discharge.The dynamic characteristics of the plasma,the generated active species,and the energy transfer mechanisms in both positive discharge(PD)and negative discharge(ND)are investigated by using fast-exposure intensified charge coupled device(ICCD)images and time-resolved optical emission spectra.The experimental results show that the discharge intensity,number of discharge channels,and discharge volume are obviously enhanced when the multi-needle electrode is replaced by a multihollow needle electrode.During a single voltage pulse period,PD mainly develops in a streamer mode,which results in a stronger discharge current,luminous intensity,and E/N compared with the diffuse mode observed in ND.In PD,as the gap between dielectric beads changes from 0 to250μm,the discharge between the dielectric bead gap changes from a partial discharge to a standing filamentary micro-discharge,which allows the plasma to leave the local area and is conducive to the propagation of surface streamers.In ND,the discharge only appears as a diffusionlike mode between the gap of dielectric beads,regardless of whether there is a discharge gap.Moreover,the generation of excited states N_(2)^(+)(B^(2)∑_(u)^(+))and N2(C^(3)Π_(u))is mainly observed in PD,which is attributed to the higher E/N in PD than that in ND.However,the generation of the OH(A^(2)∑^(+))radical in ND is higher than in PD.It is not directly dominated by E/N,but mainly by the resonant energy transfer process between metastable N_(2)(A^(3)∑_(u)^(+))and OH(X^(2)Π).Furthermore,both PD and ND demonstrate obvious energy relaxation processes of electron-to-vibration and vibration-to-vibration,and no vibration-to-rotation energy relaxation process is observed.

基于新型阵列的储罐底板声发射定位方法

针对传统声发射源定位方法对储罐底板中心位置附近声发射信号接收不佳的问题,设计出一种8⁃4⁃2⁃1型伞状定位阵列,通过改变定位传感器组合,并将模式识别技术融入到新型阵列定位算法中,解决了罐底定位容易出现的漏定位和伪定位等问题,最后通过对比试验对该定位阵列的效果进行验证。试验结果表明,新型定位算法对罐底中心位置的定位精度提升了10.99%,重复定位、伪定位问题对定位结果的影响降低了31.22%。

医院SPECT/CT机房工作人员甲状腺、眼晶状体和手部受照辐射水平及其防护研究

目的:对单光子发射型电子计算机断层扫描与X射线计算机断层扫描(SPECT/CT)设备机房工作人员甲状腺、眼晶状体和手部的受照剂量及辐射水平进行研究,为评估SPECT/CT机房工作人员受到辐射危害及放射防护提供参考。方法:选取2019年2月至2020年10月中国医学科学院肿瘤医院核医学科在SPECT/CT机房1和SPECT/CT机房2的工作人员各2名,采用光致发光(OSL)剂量计对4名SPECT/CT机房工作人员7个季度的受照剂量进行监测,4名工作人员摆位总量为20 682例患者。工作人员在工作中常规穿戴防护铅衣(0.5 mmPb)和铅围脖(0.5 mmPb)等防护用品,将OSL剂量计分别佩戴在每名机房摆位人员的甲状腺、眼睛附近位置和手部。4名工作人员每人佩戴1套(甲状腺、眼睛附近和手部位置共3枚)OSL剂量计。佩戴OSL剂量计时长为21个月,对甲状腺部位的10 mm深度个人剂量当量[Hp(10)]、眼晶状体部位的3 mm深度个人剂量当量[Hp(3)]和手部的0.07 mm深度个人剂量当量[Hp(0.07)]进行季度监测,评估SPECT/CT机房4名工作人员甲状腺、眼晶状体和手部的受照剂量。4名工作人员均接受常规外照射个人剂量监测。结果:4名工作人员每人年平均摆位例数约2 955例患者,其中仅1名工作人员甲状腺、眼晶状体和手部年平均所受的剂量最高,分别为0.129、0.071和0.151 mSv/a,但远低于放射工作人员剂量约束值5、5和125 mSv/a。结论:SPECT/CT机房4名工作人员为患者摆位时直接接触注射过放射性药物的患者,但其甲状腺、眼睛和手部受照剂量均远低于放射工作人员剂量约束值。按要求合理使用个人防护用品能够有效防护摆位工作中的辐射。

全球气候治理义务的构建:自愿合作向合作义务的转变

有效的温室气体排放控制和减缓是全球气候治理的根本所在,涉及全球根本利益,需要广泛的国际合作。气候变化《巴黎协定》规定了温室气体自愿减排合作机制和减排相互支持的合作机制,要求缔约方遵守和采取一系列的减排合作行为,实现温室气体减排国家自主贡献。受制于国际法运行体系内没有超国家行为体保障其实施,以及国际法违反行为义务引发的结果义务以“不利法律后果”即法律责任形式出现难以达成各国一致同意与顺利实施等因素,导致这些合作机制下的行为规则只有行为义务而缺乏结果义务,使得包括自愿减排合作机制和减排相互支持合作机制在内的减排国际合作实际效果不佳,形成了全球减排国际合作桎梏。全球气候治理国际合作义务是全球气候治理中,基于共同责任而产生的国家对国际社会整体承担的一般法律义务、新型的注意义务;从法律规范要素的肯定性后果要素和否定性后果要素两个方面充实该义务的规范效果即结果义务,能有效克服这些制约因素,保障全球气候治理国际合作义务得以切实履行,并有效服务于实现联合国《气候变化框架公约》和气候变化《巴黎协定》确立的全球气候治理目标。