Analysis and Suppression Design of Stray Light Pollution in a Spectral Imager Loaded on a Polar-Orbiting Satellite.

As the non-imaging light of optical instruments, stray light has an important impact on normal imaging and data quantification applications. The FY-3D Medium Resolution Spectral Imager (MERSI) operates in a sun-synchronous orbit, with a scanning field of view of 110° and a surface imaging width of more than 2300 km, which can complete two coverage observations of global targets per day with high detection efficiency. According to the characteristics of the operating orbit and large-angle scanning imaging of MERSI, a stray light radiation model of the polar-orbiting spectrometer is constructed, and the design requirements of stray light suppression are proposed. Using the point source transmittance (PST) as the merit function of the stray light analysis method, the instrument was simulated with all stray light suppression optical paths, and the effectiveness of stray light elimination measures was verified using the stray light test. In this paper, the full-link method of "orbital stray light radiation model-system, internal and external simulation design-system analysis and actual test comparison verification" is proposed, and there is a maximum decrease in the system's PST by about 10 times after applying the stray light suppression's optimization design, which can provide a general method for stray light suppression designs for polar-orbit spectral imagers.

Stray Light Analysis and Suppression of the Visible to Terahertz Integrated Cloud Detection Optical System.

The wide-spectrum integrated imaging method can simultaneously obtain the spectral information of different spectral bands of the same target, which is conducive to the realization of the high-precision detection of target characteristics, and can simultaneously obtain more comprehensive elements such as the structure, shape, and microphysical parameters of the cloud. However, for stray light, the same surface has different characteristics at different wavelengths, and a wider spectral band means more complex and diverse sources of stray light, which renders the analysis and suppression of stray light more difficult. In this work, according to the characteristics of the visible-to-terahertz integrated optical system design scheme, the influence of material surface treatment on stray light was studied; the stray light analysis and optimization of the whole link of light transmission were carried out. For the sources of stray light in different channels, targeted suppression measures such as front baffle, field stop, special structure baffle, and reflective inner baffle were adopted. The simulation results indicate that when the off-axis field of view was greater than 10°. The point source transmittance (PST) of the terahertz channel is on the order of 10-4, the visible and infrared channels are less than 10-5, and the final terahertz PST was on the order of 10-8, while visible and infrared channels were lower than 10-11. Here, we present a method for stray light suppression based on conventional surface treatments for broadband imaging systems.

Association of genetic polymorphisms of miR-145 gene with telomere length in omethoate-exposed workers.

Omethoate, an organophosphorous pesticide, causes a variety of health effects, especially the damage of chromosome DNA. The aim of the study was to assess the correlation between polymorphisms of encoding miRNA genes and telomere length in omethoate-exposure workers. 180 workers with more than 8 years omethoate-exposure and 115 healthy controls were recruited in the study. Genotyping for the selected single nucleotide polymorphisms loci were performed using the flight mass spectrometry. Real-time fluorescent quantitative polymerase chain reaction(PCR) method was applied to determine the relative telomere length(RTL) in human peripheral blood leukocytes DNA. After adjusting the covariate of affecting RTL, covariance analysis showed that the female was significantly longer than that of the male in control group(P < 0.046). For the miR-145 rs353291 locus, this study showed that RTL of mutation homozygous AG+GG individuals was longer than that of wild homozygous AA in the exposure group (P = 0.039). In the control group, RTL with wild homozygous TT genotype in miR-30a rs2222722 polymorphism locus was longer than that of the mutation homozygous CC genotype (P = 0.038). After multiple linear regression analysis, the independent variables of entering into the model were omethoate-exposure (b = 0.562, P < 0.001), miR-145 rs353291 (AG+GG) (b = 0.205, P = 0.010). The prolongation of relative telomere length in omethoate exposed workers was associated with AG+GG genotypes in rs353291 polymorphism of encoding miR-145 gene.

Telomere length in workers was effected by omethoate exposure and interaction between smoking and p21 polymorphisms.

Omethoate is an organophosphorus pesticide that poses a major health hazard, especially DNA damage. The purpose of this study was to investigate the factors affecting telomere length in workers exposed to omethoate by analyzing the interaction between cell cycle gene polymorphism and environmental factors. The exposure group consisted of 118 workers exposed to omethoate for 8-10 years, the control group comprised 115 healthy people without occupational toxicant exposure history. The telomere length of genomic DNA from peripheral blood leucocyte was determined with real-time PCR. Polymerase chain reaction and restriction fragment length polymorphism was used to detect the polymorphisms in p53, p21 and MDM2 gene. The telomere length in the (CA + AA) genotypes for p21 rs1801270 polymorphism was longer than that in the CC genotype in control group (P = 0.015). The generalized linear model analysis indicated the interaction of the p21 rs1801270 polymorphic (CA + AA) genotypes and smoking has a significant effect on telomere length (ß = -0.258, P = 0.085). The prolongation of telomere length in omethoate-exposed workers was associated with genotypes (CA + AA) of p21 rs1801270, and interactions of (CA + AA) genotypes and smoking factor.

Association of genetic polymorphisms of telomere binding proteins with cholinesterase activity in omethoate-exposed workers.

Omethoate, an organophosphorous pesticide, can cause a variety of health effects, especially the decrease of cholinesterase activity. The aim of this study is to explore the association of genetic polymorphisms of telomere binding proteins with cholinesterase activity in omethoate-exposed population. Cholinesterase activities in whole blood, red blood cell and plasma were detected using acetylthiocholine and dithio-bis-(nitrobenzoic acid) method; Genetic Genotyping of POT1 rs1034794, POT1 rs10250202, TERF1 rs3863242 and TERT rs2736098 were performed with PCR-RFLP. The cholinesterase activities of whole blood, red blood cells and plasma in exposure group are significantly lower than that of the control group (P < 0.001). Multivariate analysis indicates that exposure group (b = - 1.016, P < 0.001), agender (b = 0.365, P < 0.001), drinking (b = 0.271, P = 0.004) and TERF1rs3863242 (b = - 0.368, P = 0.016) had an impact on cholinesterase activities. The results suggest that individual carrying AG+GG genotypes in TERF1 gene rs3863242 polymorphism were susceptible to damage in cholinesterase induced by omethoate.

Directed differentiation of chick embryonic germ cells into neural cells using retinoic acid induction in vitro.

Embryonic germ cells (EG) are undifferentiated stem cells isolated from cultured primordial germ cells (PGC). Like embryonic stem cells (ES), EG are also capable of proliferation and self-renewal and have the capacity to differentiate in vitro into all cell types. To date, it has been proven that ES are capable of directed differentiation into neural precursors and progenies in mammals. However, similar studies on EG in mammals and other species are few. This investigation aimed to induce chick EG to differentiate into neural cells and compare the difference of efficiency between directed differentiation and spontaneous differentiation. EG were isolated and identified from 5.5-day chick gonadal PGC, incubated and passaged in conditioned medium. After the formation of embryoid bodies (EB), EB were grown in suspension and induced by retinoic acid (RA), using a protocol named 4-/4+, to make the formation of neurospheres and progenies. RT-PCR and immunocytochemistry analysis demonstrated that neural-specific markers can be detected after directed induction. Moreover, EG differentiated into neural lineage cells using 4-/4+ protocol much more efficiently than that in the spontaneous differentiation with fluorescence-activated cell sorting (FACS) analysis. The results revealed that RA can obviously promote the directed differentiation of chick EG into neural lineage.

Telomere Length in Workers Was Effected by Omethoate Exposure, GSTM1 Deletion, Interaction Between Smoking and GSTP1 Polymorphisms.

OBJECTIVE: The aim of this study was to explore the association between telomere length and metabolizing enzyme gene polymorphisms and environmental factors in omethoate-exposed workers. METHODS: The gene-environment interactions were analyzed with generalized linear model method. RESULTS: The relative telomere lengths in the individuals with GSTM1-deletion were longer than that in non-deletion genotype in the control group (P = 0.011); the relative telomere lengths with GG+AG genotypes in GSTP1 rs1695 were longer than that of AA genotype in the exposure group (P = 0.039). The interaction between the GG+AG genotypes in GSTP1 rs1695 and smoking exposure had significant effect on telomere length (P < 0.05). CONCLUSIONS: The prolongation of relative telomere length in omethoate-exposed workers was associated with GSTM1-deletion, GG+AG genotypes, and interactions of GG+AG genotypes and smoking factor.

Systemic administration of catalpol prevents D-galactose induced mitochondrial dysfunction in mice.

The aim of this work was to evaluate the mechanisms involved in the effects of catalpol on mitochondrial function through the measurements of nitric oxide synthase (NOS) activity, reactive oxygen species (ROS) production, respiratory complex activities and mitochondrial membrane potential (MMP) in the brain cortex and hippocampus mitochondria of senescent mice induced by d-galactose. Except control group, mice were subcutaneously injected with d-galactose (150 mg/kg body weight) for 6 weeks. Meanwhile, drug group mice were treated with catalpol (2.5, 5, 10mg/kg body weight) and piracetam (300 mg/kg body weight) for the last 2 weeks. The results indicated that respiratory complex activities decreased while NOS activities increased in d-galactose treated mice brain. The production of ROS increased remarkably and MMP collapsed in the brain of senescent mice induced by d-galactose. Administration of catalpol for 2 weeks significantly decreased ROS production and NOS activities, in accordance with its increase on complex activities and MMP level. Our results suggest that in vivo effects of catalpol on mitochondrial function can occur through different mechanisms, involving inhibiting NOS activity and ROS production, increasing respiratory complex activities and MMP level.