radiation

摘要： Ionizing radiation can cause changes in nervous system function.However,the underlying mechanism remains unclear.In this study,Caenorhabditis elegans(C.elegans)was irradiated with 75 Gy of 60Co whole-bodyγradiation.Behavioral indicators(head thrashes,touch avoidance,and foraging),and the development of dopaminergic neurons related to behavioral function,were evaluated to assess the effects of ionizing radiation on nervous system function in C.elegans.Various behaviors were impaired after whole-body irradiation and degeneration of dopamine neurons was observed.This suggests that 75 Gy ofγradiation is sufficient to induce nervous system dysfunction.The genes nhr-76 and crm-1,which are reported to be related to nervous system function in human and mouse,were screened by transcriptome sequencing and bioinformatics analysis after irradiation or sham irradiation.The expression levels of these two genes were increased after radiation.Next,RNAi technology was used to inhibit the expression of crm-1,a gene whose homologs are associated with motor neuron development in other species.Downregulation of crm-1 expression effectively alleviated the deleterious effects of ionizing radiation on head thrashes and touch avoidance.It was also found that the expression level of crm-1 was regulated by the nuclear receptor gene nhr-76.The results of this study suggest that knocking down the expression level of nhr-76 can reduce the expression level of crm-1,while down-regulating the expression level of crm-1 can alleviate behavioral disorders induced by ionizing radiation.Therefore,inhibition of crm-1 may be of interest as a potential therapeutic target for ionizing radiation-induced neurological dysfunction.

摘要： BACKGROUND Contemporary treatment of stageⅡ/Ⅲrectal cancer combines chemotherapy,chemoradiation,and surgery,though the sequence of surgery with neoadjuvant treatments and benefits of minimally-invasive surgery(MIS)is debated.AIM To describe patterns of surgical approach for stageⅡ/Ⅲrectal cancer in relation to neoadjuvant therapies.METHODS A retrospective cohort was created using the National Cancer Database.Primary outcome was rate of sphincter-sparing surgery after neoadjuvant therapy.Secondary outcomes were surgical approach(open,laparoscopic,or robotic),surgical quality(R0 resection and 12+lymph nodes),and overall survival.RESULTS A total of 38927 patients with clinical stageⅡorⅢrectal adenocarcinoma underwent surgical resection from 2010-2016.Clinical stageⅡpatients had neoadjuvant chemoradiation less frequently compared to stageⅢ(75.8%vs 84.7%,P<0.001),but had similar rates of total neoadjuvant therapy(TNT)(27.0%vs 27.2%,P=0.697).Overall rates of total mesorectal excision without sphincter preservation were similar between clinical stageⅡandⅢ(30.0%vs 30.3%)and similar if preoperative treatment was chemoradiation(31.3%)or TNT(30.2%).Over the study period,proportion of cases approached laparoscopically increased from 24.9%to 32.5%and robotically 5.6%to 30.7%(P<0.001).This cohort showed improved survival for MIS approaches compared to open surgery(laparoscopy HR 0.85,95%CI 0.78-0.93,and robotic HR 0.82,95%CI 0.73-0.92).CONCLUSION Sphincter preservation rates are similar across stageⅡandⅢrectal cancer,regardless of delivery of preoperative chemotherapy,chemoradiation,or both.At a national level,there is a shift to predominantly MIS approaches for rectal cancer,regardless of whether sphincter sparing procedure is performed.

摘要： An upper atmospheric phenomenon i.e., sprites can be thought to be mainly caused by the propagation of positive corona streamers. This research presents the formulation for the calculation of radiation power received from the propagating corona streamers responsible for the origination of the sprites. The produced magnetic field variation using the calculated electromagnetic radiation power is found to be similar with the previous observation-based research work.

摘要： BACKGROUND Bone marrow(BM)suppression is one of the most common side effects of radiotherapy and the primary cause of death following exposure to irradiation.Despite concerted efforts,there is no definitive treatment method available.Recent studies have reported using mesenchymal stromal cells(MSCs),but their therapeutic effects are contested.AIM We administered and examined the effects of various amounts of adipose-derived MSCs(ADSCs)in mice with radiation-induced BM suppression.METHODS Mice were divided into three groups:Normal control group,irradiated(RT)group,and stem cell-treated group following whole-body irradiation(WBI).Mouse ADSCs(mADSCs)were transplanted into the peritoneal cavity either once or three times at 5×10^(5) cells/200μL.The white blood cell count and the levels of,plasma cytokines,BM mRNA,and BM surface markers were compared between the three groups.Human BM-derived CD34+hematopoietic progenitor cells were co-cultured with human ADSCs(hADSCs)or incubated in the presence of hADSCs conditioned media to investigate the effect on human cells in vitro.RESULTS The survival rate of mice that received one transplant of mADSCs was higher than that of mice that received three transplants.Multiple transplantations of ADSCs delayed the repopulation of BM hematopoietic stem cells.Anti-inflammatory effects and M2 polarization by intraperitoneal ADSCs might suppress erythropoiesis and induce myelopoiesis in sub-lethally RT mice.CONCLUSION The results suggested that an optimal amount of MSCs could improve survival rates post-WBI.

摘要： Use of ionizing radiation during cardiac catheterization interventions adversely impacts both the patients and medical staff.In recent years,radiation dose in cardiac catheterization interventions has become a topic of increasing interest in interventional cardiology and there is a strong interest in reducing radiation exposure during the procedures.This review presents the current status of radiation protection in the cardiac catheterization laboratory and summarizes a practical approach for radiation dose management for minimizing radiation exposure.This review also presents recent innovations that have clinical potential for reducing radiation during cardiac interventions.

摘要： This paper is devoted to the analysis of the heat transfer and Navier’s slip effects in a non-Newtonian Jeffrey fluid flowing past a stretching/shrinking sheet.The nanoparticles,namely,Cu and Al_(2)O_(3)are used with a water-based fluid with Prandtl number 6.272.Velocity slip flow is assumed to occur when the characteristic size of the flow system is small or the flow pressure is very small.By using the similarity transformations,the governing nonlinear PDEs are turned into ordinary differential equations(ODE’s).Analytical results are presented and analyzed for various values of physical parameters:Prandtl number,Radiation parameter,stretching/shrinking parameter and mass transpiration for the flow and heat transfer.The considered problem is relevant to various physical applications in the field of engineering,e.g.,the production of certain materials,the preparation of plastic and rubber sheets and glass blowing.It is shown that the considered nanofluid increases the thermal efficiency.The nanoparticles act as a heater by increasing the solid volume fraction and thermal radiation.Vice versa,they can act as a cooler if the strength of magnetic field is increased.The flow strength decreases by increasing the values of Deborah number.

摘要： Electron spin resonance techniques were employed to investigate the effects of the absorbed dose and post-irradiation conditions on the evolution and decay of free-radicals in cross-linked polytetrafluoroethylene(XPTFE),induced byγ-ray radiation.Chain-end free-radicals,chain alkyl free-radicals,and tertiary alkyl free-radicals were detected when XPTFE was irradiated under Ar atmosphere.The corresponding peroxy free-radicals were formed upon exposure of irradiated XPTFE to air;the freeradicals concentration first increased linearly with increasing absorbed dose and then gradually saturated.The free-radicals yield under air atmosphere was greater than that under Ar,and the peroxy free-radicals were preserved for a relatively long time when irradiated XPTFE was stored under air atmosphere.The chain alkyl free-radicals may be converted to chain end free-radicals byβ-scission,while chain end free-radicals are more sensitive to oxygen than chain alkyl free-radicals.When the annealing temperature was raised above the a-transition temperature of XPTFE,the decay of the free-radicals was greatly affected and accelerated by the motion of the molecules over the long range.

摘要： BACKGROUND Duodenal-type follicular lymphoma(D-FL)has been recognized as a rare entity that accounts for approximately 4%of primary gastrointestinal lymphomas.D-FL follows an indolent clinical course compared with common nodal FL and is generally considered to have a better prognosis.Therefore,the“watch and wait”approach is frequently adopted as the treatment method.Alternatively,there is an option to actively intervene in D-FL.However,the long-term outcomes of such cases are poorly understood.AIM To clarify the clinical outcomes after long-term follow-up in cases of D-FL with treatment intervention.METHODS We retrospectively analyzed patients who met the following criteria:the lesion was confirmed by endoscopy,the diagnosis of D-FL was confirmed histopathologically,and the patient was followed-up for more than 10 years after the intervention at our center.RESULTS We identified 5 cases of D-FL.Two patients showed a small amount of bone marrow involvement(Stage IV).Rituximab was used as a treatment for remission in all 5 patients.It was also used in combination with chemotherapy in 2 Stage IV patients as well as for maintenance treatment.Radiation therapy was performed in 2 cases,which was followed by complete remission(CR).Eventually,all 5 patients achieved CR and survived for more than 10 years.However,3 patients experienced recurrence.One patient achieved a second CR by retreatment,and in another case,the lesion showed spontaneous disappearance.The remaining patient had systemic widespread recurrence 13 years after the first CR.Biopsy results suggested that the FL lesions were transformed into diffuse large B-cell lymphoma.The patient died 4 years later despite receiving various chemotherapies.CONCLUSION In this study,the treatment for patients of D-FL in Stage IV was successful.In the future,criteria for how to treat“advanced”D-FL should be established based on additional cases.This study of patients with D-FL indicates that whole-body follow-up examinations should continue for a long time due to a fatal recurrence 13 years after reaching CR.

摘要： In 2021,China Space Station(CSS)was assembled and constructed in-orbit,which provided a broad space platform for space medicine and space life sciences research.Space medicine focuses on the systematic risks that restrict long-term manned spaceflight.It carries out systematic research on the impact and countermeasure technology of long-term weightlessness on astronauts’health,space radiation on astronauts’health,behavior and ability,advanced on-orbit monitoring and medical disposal technology,and traditional space medical application technology by the space medicine experiment platform on human body and cell.It has accumulated valuable data on space environmental effects and human factors research,established a“human system risk”research system,obtained new knowledge and discoveries of space medicine,and explored countermeasure technologies of new characteristics.Moreover,a series of achievements have been made in the basic research on the mechanism of the special space environmental effect,which provides a solid foundation for the implementation of space missions.

摘要： The effects of plasma radiation on the nonlinear evolution of neo-classical tearing modes are investigated based on a set of reduced magnetohydrodynamic equations.It is found that the radiation can reduce the pressure near the rational surface.During the nonlinear evolution,the magnitude of perturbed bootstrap current is drastically enhanced in the presence of the radiation.Besides,the radiation can increase the growth rate of the magnetic islands by diminishing the pressure,such that the magnetic islands do not saturate compared with that without radiation.On the other hand,with the increase of the ratio of parallel to perpendicular transport coefficientχ‖/χ⊥,the reduction of pressure can further increase the growth rate of magnetic islands in the presence of plasma radiation.Finally,the mechanisms of the destabilizing effects driven by the radiation are discussed in detail as well.