Two-dimensional particle-in-cell modeling of blow-off impulse by X-ray irradiation

Space objects such as spacecraft or missiles may be exposed to intense X-rays in outer space,leading to severe damage.The reinforcement of these objects to reduce the damage caused by X-ray irradiation is a significant concern.The blow-off impulse(BOI)is a crucial physical quantity for investigating material damage induced by X-ray irradiation.However,the accurate calculation of BOI is challenging,particularly for large deformations of materials with complex configurations.In this study,we develop a novel two-dimensional particle-in-cell code,Xablation2D,to calculate BOIs under far-field X-ray irradiation.This significantly reduces the dependence of the numerical simulation on the grid shape.The reliability of this code is verified by simulation results from open-source codes,and the calculated BOIs are consistent with the experimental and analytical results.

Effects of Corticosterone, cAMP, cGMP, Ca^(2+), and Protein Kinase C on Apoptosis of Mouse Thymocytes Induced by X-ray Irradiation

Objective To observe the effects of signal factors of corticosterone （CS）, cAMP, cGMP, Ca^2＋ and protein kinase C （PKC） on lymphocyte apoptosis in mouse thymus induced by X-rays of 4 Gy in vitro. Methods The DNA lyric rate for thymocytes was measured by fluomspectrophotometry. Results The DNA lyric rate for thymocytes 4-8 hours after irradiation with 2-8 Gy was significantly higher than that in the control （P〈0.01）. As compared with the control, the DNA lyric rate for thymocytes treated with 0.01 μnol/L CS （P〈0.01）, 50 ng/mL cAMP （P〈0.01）, 0.05-0.4 μg/mL ionomycin （Iono, P〈0.05 or P〈0.01） or 0.05-0.4 ng/mL phorbol myristate acetate （PMA, P〈0.05 or P〈0.01）, respectively, was significantly increased, while the rate for thymocytes treated with 50 ng/mL cGMP was not significantly increased. The DNA lyric rate for thymocytes treated with 0.01 μmol/L CS （P〈0.01）, 50 ng/mL cAMP （P〈0.01）, 0.2 and 0.4 μg/mL Iono （P〈0.05）, and 0.2 and 0.4 ng/mL PMA （P〈0.05） plus 4-Gy irradiation, respectively, was significantly higher than that treated with single 4-Gy irradiation, while the rate for thymocytes treated with 50 ng/mL cGMP plus 4-Gy irradiation was not increased. When both 0.4 I.tg/mL Iono and 0.4 ng/mL PMA acted on the thymocytes, the DNA lyric rate for thymocytes was significantly higher than that in the control （P〈0.01）, the DNA lytic rate for thymocytes treated with both 0.4 μg/mL Iono and 0.4 ng/mL PMA plus 4-Gy irradiation was significantly higher than that treated with single 4-Gy irradiation （P〈0.05）, but was Iono plus 4-Gy irradiation or 0.4 ng/mL PMA plus 4-Gy irradiation. can promote thymocyte apoptosis induced by larger dose X-rays. not significantly higher than that treated with 0.4 μg/mL Conclusion CS, cAMP, Ca^2＋, and PKC signal factors can promote thymocyte apoptosis induced by larger dose X-rays.

Randomized clinical trial on seven-day-per-week continuous accelerated irradiation for patients with esophageal carcinoma: Preliminary report on tumor response and acute toxicity

AIM: Tumor response and normal tissue toxicity of seven-day-per-week continuous accelerated irradiation (CAIR) for patients with esophageal carcinoma were evaluated and compared to conventional irradiation (CR). METHODS: Sixty patients with squamous cell carcinoma of the esophagus were randomized into two groups: the CAIR group (30 patients) and the CR group (30 pa- tients). Patients in the CAIR group received radiotherapy (RT) with 2 Gy/fraction per day at 7 d/wk with a total dose of 50-70 Gy (average dose 64.2 Gy). The overall time of irradiation was 3.6-5.0 wk (average 4.6 wk). RT in the CR group was 2 Gy/fraction per day at 5 d/wk with a total dose of 40-70 Gy (average dose 61.7 Gy). The overall time of irradiation was 4.0-7.0 wk (average 6.4 wk). RESULTS: The data showed that the immediate tumor response to RT was better in the CAIR group than in the CR group. Efficiency rates (CR plus PR) were 82.8% (24/29) and 58.6% (17/29), respectively (P = 0.047). In both groups the incidences of esophagitis and tracheitis were insignificant (P = 0.376, 0.959), and no patient re- ceived toxicity that could not be tolerated. CONCLUSION: CAIR shortens overall treatment time and is well tolerated by patients. It may be superior to CR in enhancing the local response of tumor, but its remote effect for esophageal carcinoma awaits further follow-up.

Effect of X-ray irradiation on threshold voltage of AlGaN/GaN HEMTs with p-GaN and MIS Gates

Commercially available AlGaN/GaN high-electron-mobility transistors(HEMTs)are beginning to enter the public scene froma range of suppliers.Based on previous studies,commercial GaN-based electronics are expected to be tolerant to different types of irradiation in space.To test this assumption,we compared the characteristic electrical curves obtained at different X-ray irradiation doses for GaN HEMT devices manufactured by Infineon and Transphorm.The p-GaN-based device was found to be more robust with a stable threshold voltage,whereas the threshold voltage of the device with ametal-insulator-semiconductor gatewas found to shift first in the negative and then the positive direction.This dynamic phenomenon is caused by the releasing and trapping effects of radiation-induced charges in the dielectric layer and at the interface of irradiated devices.As such,the p-GaNgate-based GaN HEMT provides a promising solution for use as an electric source in space.

Investigation on the hydrodynamics of slab x-ray laser plasma by nonuiform line focused laser irradiation

Based on the two-dimensional model, this paper compares the hydrodynamics of slab x-ray laser plasma produced by different nonuniform line focused irradiations. It finds that the average intensity and the duration of laser pulse and the overall shape of the intensity distribution in the focal line have different influences on the plasma. Calculations show that the evolution of temperature variation is more sensitive to the pulse duration and the electron density variation is more sensitive to the pulse intensity. Pulses with duration of 200 ps to 500 ps and with intensity of 0.2 TW/cm2 to 1.0 TW/cm2 are proved acceptable in slab x-ray lasers.

3-44 Effects of X-ray and Carbon-ion Irradiation on Hematopoietic Cell Counts in the Mice Model

The hematological effects of space radiation contribute to the compromised immune defense in astronauts observed in the space environment as well as upon landing[1]. The complications associated with the hematopoietic syndrome include infection and internal hemorrhage. The decrease in peripheral blood cell counts after radiation serves not only as a marker for the severity of the exposure, but also as a marker for treatment and prognosis[2]. In the present research, we investigated the effects of whole-body heavy-ion (80 MeV/u carbon-ion) radiation and conventional X-ray (6 MV) radiation on peripheral blood cell counts in mice model. Time effects were determined to compare the effects of the different types of radiation.

αB-crystallin malondialdehyde,superoxide dismutase, and lutathione peroxidase changes in X-ray irradiated rat lens

AIM: To evaluate αB-crystallin malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPx) changes in X-ray irradiated rat lens. METHODS: Eight-week-old Sprague-Dawley male rats received X-ray irradiation to the head with rest of the body protected. The exposure dose ranged from 2 to 25 Grays (Gy). The cataract status were examined by slit lamp and rated with 'four-grade systems' post-irradiation. The lens MDA level, and the activities of SOD and GPx were measured in a short-term experiment post-irradiation, and αB-crystallin protein levels were quantified. RESULTS: The lenses of normal control and the X-ray irradiated groups with the dose up to 10 Gy remained transparent throughout the experiment. The lens first appeared tiny scatters, and even lamellar opacities in the posterior capsule 45 days post-irradiation with the dose of 15 Gy, and progressed slowly to the advance stage of cataract; while, for the higher dose (25 Gy), the opacity of lens appeared much earlier, and progressed more rapidly to mature stage of cataract within 1 month. At the end of the observation (90 days post-irradiation), almost all lenses became complete opacity with the higher dose (25 Gy). The degree of lens opacity was rated accordingly. The lens MDA level was increased, and SOD and GPx activities were decreased with a dose-dependent manner post-irradiation. The αB-crystallin protein level was decreased dose-dependently at the end point of observation. CONCLUSION: Oxidative events and αB-crystallin may play important roles in the pathogenesis of cataract in X-ray irradiated rat lens.

A new equation for activity calculation in pulse irradiation:derivation, simulation, and experimental validation

To calculate the radioactivity of product nuclides generated in pulse irradiation, it is generally assumed that the irradiation is approximately continuous in the entire irradiation period(ti) and the flux of the incoming irradiation particle can be obtained by averaging their intensity in each pulse period(T). However, this approximation fails to acknowledge the fact that the product nuclides are not created in each pulse period(T)evenly: They are only produced in a very short pulse width(tp) and then decay in a relatively long rest time(tr = T-tp). Given by the enormous number of pulses, the sum of these decays may not be negligible. To make the activity calculation in accordance with the real situation in pulse irradiation, we scrutinize the details of irradiation and decay processes in each pulse, apply the geometric series to obtain the activity superimposition of millions of pulses,and derive a novel activity equation particularly suitable for pulse irradiation. The experimental results,numerical simulations,and activity measurements from photon activation driven by a pulsed electron LINAC have confirmed the validity of this new equation. The comparison between the new and traditional equations indicates that their discrepancy could be significant under certain conditions. The limitations of the new activity equation for pulse irradiation are discussed as well.

POSTOPERATIVE IRRADIATION OF KELOIDS: ANALYSIS OF 125 PATIENTS

Between October 1985 and June 1992 Postoperative kelolds of 125 Patients were treated with superficial X-ray (100-140 Kv) and electron beam (6 and 9 MeV ), in an attempt to prevent their recurrence, 100 patients with 129 sites received a dose of 1200-4000 cGy at 200-300 cGy per fraction within one to four weeks and at intervals of one to three weeks between excision and irradiation. Rate of success In the prevention of kelold was only 28. 6% (37/ 129). However, 25 patients with 25 sites received a total dose of 1500 cGy at 500 cGy per fraction starting within one week after excision and at Intervals of 96 hours. The success rate was 84% (21/25).

Evaluation of the Effects of Irradiation of Peanut Grain by a Gamma-Ray Beam on Culture

The problems of agriculture in Senegal result in a low yield per hectare and poor seed quality contributing strongly to the decline in productivity. Mutagenesis by X- or Y-ray irradiation makes it possible to obtain genetic mutants necessary to improve production. It is in this context that we undertook this study to evaluate the effects induced on the cultivation of peanut seeds irradiated by X-rays at low doses applied in radiotherapy. X-ray irradiation of four (2, 3, 4, 5) lots of peanuts are performed with respectively 0.5, 1.5, 2 and 4 Gray using the cobalt 60 therapy device (Alcyon II). The seeding of the seeds and then the following-up of the crops during 35 days allowed us to study the parameters of germination, growth and yield. The results obtained after monitoring revealed that the irradiation did not have any significant impact on germination and would appear to temporarily inhibit the growth rate compared to the control batch. However, the decrease in weight of the harvested seeds can be explained by the absence of fertilizer during the cultivation.

High-Efficiency Synthesis and Properties of Latent Pigment Red 272DPP-BOC by Microwave Irradiation

A high-efficiency synthesis method for a latent pigment of red pigment diketo-pyrrolo-pyrrole (Pig. Red 272:272DPP), which is important as a functional organic pigment, was investigated, and the investigation results revealed that irradiation of microwaves (MWs) for several seconds to 272 DPP in NMP (N-methyl-2-pyrrolidone) solvent yielded DPP latent pigment (272DPP-BOC) at a high yield of 86.2%. Two kinds of latent-pigment crystals, namely, red and yellow, were obtained by recrystallization, and it was found that the fluorescence-emission properties of the two kinds differ significantly. Single-crystal X-ray structural analysis showed that the difference in the fluorescence-emission properties of the two types is derived from the difference in their crystal structures.

Time-resolved K-shell x-ray spectra of nanosecond laser-produced titanium tracer in gold plasmas

A study of a nanosecond laser irradiation on the titanium-layer-buried gold planar target is presented. The timeresolved x-ray emission spectra of titanium tracer are measured by a streaked crystal spectrometer. By comparing the simulated spectra obtained by using the FLYCHK code with the measured titanium spectra, the temporal plasma states, i.e.,the electron temperatures and densities, are deduced. To evaluate the feasibility of using the method for the characterization of Au plasma states, the deduced plasma states from the measured titanium spectra are compared with the Multi-1D hydrodynamic simulations of laser-produced Au plasmas. By comparing the measured and simulated results, an overall agreement for the electron temperatures is found, whereas there are deviations in the electron densities. The experiment–theory discrepancy may suggest that the plasma state could not be well reproduced by the Multi-1D hydrodynamic simulation, in which the radial gradient is not taken into account. Further investigations on the spectral characterization and hydrodynamic simulations of the plasma states are needed. All the measured and FLYCHK simulated spectra are given in this paper as datasets. The datasets are openly available at http://www.doi.org/10.57760/sciencedb.j00113.00032.

Establishment of NaLuF_(4):15%Tb-based low dose X-PDT agent and its application on efficient antitumor therapy

X-ray excited photodynamic therapy(X-PDT)is the bravo answer of photodynamic therapy(PDT)for deep-seated tumors,as it employs X-ray as the irradiation source to overcome the limitation of light penetration depth.However,high X-ray irradiation dose caused organ lesions and side effects became the major barrier to X-PDT application.To address this issue,this work employed a classic-al co-precipitation reaction to synthesize NaLuF_(4):15%Tb^(3+)(NLF)with an average particle size of(23.48±0.91)nm,which was then coupled with the photosensitizer merocyanine 540(MC540)to form the X-PDT system NLF-MC540 with high production of singlet oxygen.The system could induce antitumor efficacy to about 24%in relative low dose X-ray irradiation range(0.1-0.3 Gy).In vivo,when NLF-MC540 irradiated by 0.1 Gy X-ray,the tumor inhibition percentage reached 89.5%±5.7%.The therapeutic mechanism of low dose X-PDT was found.A significant increase of neutrophils in serum was found on the third day after X-PDT.By immunohistochemical staining of tumor sections,the Ly6G^(+),CD8^(+),and CD11c^(+)cells infiltrated in the tumor microenvironment were studied.Utilizing the bilat-eral tumor model,the NLF-MC540 with 0.1 Gy X-ray irradiation could inhibit both the primary tumor and the distant tumor growth.De-tected by enzyme linked immunosorbent assay(ELISA),two cytokines IFN-γand TNF-αin serum were upregulated 7 and 6 times than negative control,respectively.Detected by enzyme linked immune spot assay(ELISPOT),the number of immune cells attributable to the IFN-γand TNF-αlevels in the group of low dose X-PDT were 14 and 6 times greater than that in the negative control group,respectively.Thus,it conclude that low dose X-PDT system could successfully upregulate the levels of immune cells,stimulate the secretion of cy-tokines(especially IFN-γand TNF-α),activate antitumor immunity,and finally inhibit colon tumor growth.

基于连续波功率放大器的HIRF试验技术研究

通过本试验技术的研究,形成在常规半电波暗室内开展部分高功率微波辐射试验的目的,使用连续波辐照设备进行相关测试,可作为低成本高功率微波辐射试验的推广,同时试验过程不受样品尺寸大小影响,为后续相关设备的试验考核提供技术参考。

间隙和持续蓝光照射治疗新生儿黄疸的对比研究

比较间隙蓝光照射与持续蓝光照射两种治疗模式在新生儿黄疸治疗中的疗效差异。选择2022年1月—2023年1月期间经临床诊断为新生儿黄疸的80名患儿作为研究对象。将患儿随机分入对照组(40例,接受间隙蓝光照射)和观察组(40例,接受持续蓝光照射)。对两组患儿进行详细观察和护理,记录治疗过程中的胆红素水平变化。治疗结束后,观察组患儿的血清胆红素水平较对照组明显下降,治疗效果显著改善(P<0.05)。观察组的新生儿黄疸临床症状得到更迅速的缓解,治愈时间明显缩短(P<0.05)。结果表明,在新生儿黄疸治疗中,持续蓝光照射比间隙蓝光照射更有效。

Enhanced removal of X-ray-induced carbon contamination using radio-frequency Ar/H_2 plasma

Removal of X-ray-induced carbon contamination on beamline optics was studied using radio-frequency plasma with an argon/hydrogen(Ar/H_2) mixture. Experiments demonstrated that the carbon removal rate with Ar/H_2 plasma was higher than that with pure hydrogen or argon. The possible mechanism for this enhanced removal was discussed. The key working parameters for Ar/H_2 plasma removal were determined, including the optimal vacuum pressure, gas mixing ratio, and source power. The optimal process was performed on a carbon-coated multilayer, and the reflectivity was recovered.

Proteomic analysis of energy metabolism and signal transduction in irradiated melanoma cells

AIM: To analyze proteomic and signal transduction alterations in irradiated melanoma cells. METHODS: We combined stable isotope labeling with amino acids in cell culture (SILAC) with highly sensitive shotgun tandem mass spectrometry (MS) to create an efficient approach for protein quantification. Protein protein interaction was used to analyze relationships among proteins. RESULTS: Energy metabolism protein levels were significantly different in glycolysis and not significantly different in oxidative phosphorylation after irradiation. Conversely, tumor suppressor proteins related to cell growth and development were downregulated, and those related to cell death and cell cycle were upregulated in irradiated cells. CONCLUSION: Our results indicate that irradiation induces differential expression of the 29 identified proteins closely related to cell survival, cell cycle arrest, and growth inhibition. The data may provide new insights into the pathogenesis of uveal melanoma and guide appropriate radiotherapy.

超声连续流合成2-甲基-4,6-嘧啶二酮

为探索超声强化化学反应的可行性,掌握强化工艺规律,选取FOX-7前体2-甲基-4,6-嘧啶二酮(MPO)的合成作为研究对象,设计了MPO连续流合成方法。以盐酸乙脒和丙二酸二乙酯为原料,经连续缩合、酸化合成得到MPO,并利用红外光谱(IR)、质谱(MS)及元素分析等进行了结构表征;探究了超声强化作用下缩合反应的关键影响因素及工艺规律。结果表明,最佳反应条件为停留时间9min,反应温度60℃,超声功率150W,原料摩尔比n(盐酸乙脒)∶n(丙二酸二乙酯)为1∶1.15,反应液浓度1.0mol/L(以盐酸乙脒计);得到MPO收率86.6%,纯度99.7%,反应时间由传统釜式工艺的7.5h缩短至9min,大大提高了反应效率,获得的产品粒径小于100μm,粒径均匀、分散性好,表明该超声反应器连续制备效率高,有大规模的应用前景。

Continuous Low-dose-rate Irradiation of Iodine-125 Seeds Inhibiting Perineural Invasion in Pancreatic Cancer

Background：Perineural invasion （PNI） is a histopathological characteristic of pancreatic cancer （PanCa）.The aim of this study was to observe the treatment effect of continuous low-dose-rate （CLDR） irradiation to PNI and assess the PNI-related pain relief caused by iodine-125 （125I） seed implantation.Methods：The in vitro PNI model established by co-culture with dorsal root ganglion （DRG） and cancer cells was interfered under 2 and 4 Gy of 125I seeds CLDR irradiation.The orthotopic models of PNI were established,and 125I seeds were implanted in tumor.The PNI-related molecules were analyzed.In 30 patients with panCa,the pain relief was assessed using a visual analog scale （VAS）.Pain intensity was measured before and 1 week,2 weeks,and 1,3,and 6 months after 125I seed implantation.Results：The co-culture of DRG and PanCa cells could promote the growth of PanCa cells and DRG neurites.In co-culture groups,the increased number of DRG neurites and pancreatic cells in radiation group was significantly less.In orthotopic models,the PNI-positive rate in radiation and control group was 3/11 and 7/11;meanwhile,the degrees of PNI between radiation and control groups was significant difference （P 〈 0.05）.At week 2,the mean VAS pain score in patients decreased by 50% and significantly improved than the score at baseline （P 〈 0.05）.The pain scores were lower in all patients,and the pain-relieving effect was retained about 3 months.Conclusions：The CLDR irradiation could inhibit PNI of PanCa with the value of further study.The CLDR irradiation could do great favor in preventing local recurrence and alleviating pain.

Berberine potentizes apoptosis induced by X-rays irradiation probably through modulation of gap junctions

Background Clinical combination of some traditional Chinese medical herbs, including berberine, with irradiation is demonstrated to improve efficacy of tumor radiotherapy, yet the mechanisms for such effect remain largely unknown. The present study investigated the effect of berberine on apoptosis induced by X-rays irradiation and the relation between this effect and gap junction intercellular communication （GJIC）.Methods The role of gap junctions in the modulation of X-rays irradiation-induced apoptosis was explored by manipulation of connexin （Cx） expression, and gap junction function, using oleamide, a GJIC inhibitor, and berberine.Results In transfected HeLa cells, Cx32 expression increased apoptosis induced by X-rays irradiation, while inhibition of gap junction by oleamide reduced the irradiation responses, indicating the dependence of X-rays irradiation-induced apoptosis on GJIC. Berberine, at the concentrations without cytotoxicity, enhanced apoptosis induced by irradiation only in the presence of functional gap junctions.Conclusions These results suggest that berberine potentizes cell apoptosis induced by X-rays irradiation, probably through enhancement of gap junction activity.