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Ferroptosis, an iron-dependent form of regulated cell death, results in lipid peroxidation of polyunsaturated fatty acids in the cell membrane, which is catalyzed by iron ions and accumulated to lethal levels. It is mechanistically distinct from other forms of cell death, such as apoptosis, pyroptosis, and necroptosis, so it may address the problem of cancer resistance to apoptosis and provide new therapeutic strategies for cancer treatment, which has been intensively studied over the past few years. Notably, considerable advances have been made in the antitumor research of natural products due to their multitargets and few side effects. According to research, natural products can also induce ferroptosis in cancer therapies. In this review we summarize the molecular mechanisms of ferroptosis, introduce the key regulatory genes of ferroptosis, and discuss the progress of natural product research in the field of ferroptosis to provide theoretical guidance for research on natural product-induced ferroptosis in tumors.

The outbreak of novel coronavirus pneumonia in early 2020 has attracted more and more attention to the O2O teaching mode to implement the deployment of “stopping classes without teaching and learning” during epidemic prevention and control. In this paper, we take the factors influencing the development of curriculum thinking politics in the continuing education of higher education as the object and use the Bayesian network to apply the influence indicators of curriculum thinking politics to complex scenarios for causal inference to explore the development path of curriculum thinking politics in the continuing education of higher education. According to the analysis of 1205 questionnaires of adult education, 49.95% of the students think that the concept of education has the problem of “understanding but not depth”, 61.41% of the students think that the content of curriculum thinking and political education has “shallow excavation but little integration”, and 51.96% of the students think that the teaching concept has “shallow excavation but little integration”. 51.96% of the participants think that the teaching method is “traditional and less interactive”, and 38.05% of the participants think that the evaluation of education is “professional but not political”, which are the four key factors that affect the development of the course of higher education in China. This paper proposes improvement methods through the four key factors of the development of the course of thinking and politics so that the students can receive knowledge and understand the ideological and political education at the same time and naturally build up their moral character, which can achieve the effect of “embellishment”.

The purpose of the work is to research the planar source of 14C with large size by the absorbability of the anodizing membrane. The adsorption of 14C on the anodizing membrane with thickness of 4 to 12 μm were investigated. The adsorption of 14C and the uniformity of the planar source were investigated on the volume of 14C solution. The specific activity of 14C was investigated on adsorption of 14C. The fastness, the uniformity and the surface emission rate of the planar source of 14C were measured. The result shows that the uniformity of the planar source (100 mm×150 mm) of14C is precede 10%. The plateau length is 400 V, the slope of the plateau is 0.3% per 100 V. The threshold correction is 0.2%. The uncertainty of 14C source measurement is 2% (k=2). The technical parameters of the developed plane source 14C can meet the requirements of relevant standards.

The aerospace vehicles will encounter the radiation of space electrons when they are operating in extraterrestrial space. Establishing an electronic source on the ground to simulate the electronic environment, which is encountered by the aerospace vehicle in space, and to study the damage caused by related effects and the effectiveness of protective measures is an important method to ensure the safe and stable operation of aerospace vehicles. The ground simulation facility of the space electronic environment directly provides electrons in the energy range of 1.5 MeV by an electron linac, followed by a transport system to expand the electron beam size. The large energy range demands higher requirements for the design and operation of the accelerator. This paper mainly investigated the design and implementation process of the accelerator. The energy switching technology was adopted and the beam loading effects were considered. The energy switch accelerating tube consists one bunching cavity and five light speed cavities. When the energy switch is turned on, there are acceleration fields in all six cavities. When the energy switch is turned off, there are acceleration fields in the first three cavities. The beam dynamics calculation was carried out using PARMELA. The dynamic shows the electron beam can be effectively accelerated in two states, with high energy of 5.05 MeV and low energy of 0.98 MeV. The emission angle at output is less than 140 mrad, which meets the subsequent transmission requirements. Coupling characteristics under different conditions were studied. Based on the analysis and calculation of beam loading effect, input power and coupling coefficient, the coupling coefficient is determined to be 3 at the low energy level, and corresponding pulse beam current is 300 mA. The coupling coefficient of high energy level is 1.5, and corresponding beam load is 300 mA. Meantime, the magnetron-based power source output parameters were analyzed and the corresponding experimental research was carried out. The output pulse power of magnetron is adjusted from 0.7 MW to 1.8 MW, and the stability and energy spectrum of high power output can meet the demand. After the installation and commissioning of the accelerator, the energy was measured by the polyethylene dose depth distribution method. The results show that the test energy reaches 5 MeV when the pulse current is 94 mA, and the energy is 0.9 MeV when the pulse current is 334 mA. The experimental test results of the accelerator show that the electron beam meets the requirements and provides an effective and reliable electron source for the simulation device.

620 ℃ thermal aging was carried out on full Cu3Sn solder joints for various duration, the microstructure evolution of solder joints were investigated. The mechanical properties of solder joints after aging were characterized by nano indentation test and shear test. The results show that, during the thermal aging, the Cu20Sn6 is first precipitated in planar along Cu/Cu3Sn interface, it grows continuously until the complete consumption of Cu3Sn. Subsequently, Cu20Sn6 transforms to two-phase layer, which consists of Cu20Sn6 and Cu13.7Sn. As the aging time increases, Cu13.7Sn is precipitated in waves at the Cu/two-phase layer interface by consuming the two-phase layer and grows continuously until it occupies the entire interface area. Meanwhile, there is growth in the number and size of voids in the middle of the solder joint, which eventually coalesces into microcracks. The hardness of Cu20Sn6, Cu3Sn and Cu13.7Sn phases are 9.62, 7.15, 4.67 GPa, and the elasticity modulus are 146.5, 134.0, 133.2 GPa, respectively.With the increase of aging time, the shear strength of solder joints increases first and then decreases, and remains more than 20.1 MPa within 120 min. The fracture morphology and fracture path also change.

To study the new type of dosimeter with a dose up to the ultra-high dose range of MGy, the electron spin resonance (ESR) method is used to measure the signal intensity of the sample irradiated by gamma rays or electron beams. Preliminary studies have been carried out through the selection of sensitive materials, linearity after irradiation, and stability. The results showed that the quartz can be used as a raw material for ultra-high dosimeters. After 15 min 300 ℃ proper heat treatment, the signal intensity of the irradiated quartz sample can maintain good stability within one year with a change of less than 3%. The radiation dose and the E′ signal intensity of quartz are proportional to the dose range of 10-103 kGy. The fitting coefficient is above 0.99. Compared with the high-purity quartz sample without heat treatment, the stability and R2 of fitting function of quartz sample are significantly improved. Therefore, the quartz dosimeter is suitable as a working dosimeter in the ultra-high dose range.