Design of Hypervelocity-Impact Damage Evaluation Technique Based on Bayesian Classifier of Transient Temperature Attributes

With the rapid increasement of space debris on earth orbit, the hypervelocity-impact (HVI) of space debris can cause some serious damages to the spacecraft, which can affect the operation security and reliability of spacecraft. Therefore, the damage detection of the spacecrafts has become an urgent problem to be solved. In this paper, a method is proposed to detect the damage of spacecraft. Firstly, a variable-interval method is proposed to extract the effective information from the infrared image sequence. Secondly, in order to mine the physical meaning of the thermal image sequence, five attributes are used to construct a feature space. After that, a Naive Bayesian classifier is established to mine the information of different damaged areas. Then, a maximum interclass distance function is used choose the representative of each class. Finally, in order to visualize damaged areas, the Canny operator is used to extract the edge of the damage. In the experiment, ground tests are used to simulate hypervelocity impacts in space. Historical data of natural damaged material and artificial damaged material are used to build different classifiers. After that, the effective of classifiers is illustrated by accuracy, F-score and AUC. Then, two different types of materials are detected by proposed method, Independent Component Analysis (ICA) and Fuzzy C-means (FCM). The results show that the proposed method is more accurate than other methods

Study of Salicylic Acid Influence on Seedling Growth and Nitrogen Metabolism in Watermelon (Citrullus lanatus L.)

Salicylic acid is involved in the regulation of metabolic activity and defense mechanism in plants under various stress conditions. Present study was conducted to determine the effects of salicylic acid (10 to 500 μM) on seedling growth, development and nitrogen use efficiency in watermelon (Citrullus lanatus L.) plants with or without nitrogen nutrient. Salicylic acid increased contents of chlorophyll, total non-structural carbohydrate and total nitrogen, as well as nitrate assimilation through the induction of nitrate reductase (EC 1.6.6.1) activity in isolated watermelon cotyledons. Accumulation of salicylic acid was two-fold higher in cotyledons without nitrate supply in comparison to that with nitrate supply. Further 50 μM of SA induced enhancement in seed germination and growth characteristics. However higher salicylic acid concentrations inhibited above physiological characteristics. Results show that, field application of salicylic acid need optimum physiological concentration (e.g., 50 μM) to increase nitrogen use efficiency particularly during germination and seedling growth

Cu^{2+}-Chelating Mesoporous Silica Nanoparticles for Synergistic Chemotherapy/Chemodynamic Therapy

In this study, a pH-responsive controlled-release mesoporous silica nanoparticle (MSN) formulation was developed. The MSNs were functionalized with a histidine (His)-tagged targeting peptide (B3int) through an amide bond, and loaded with an anticancer drug (cisplatin (CP)) and a lysosomal destabilization mediator (chloroquine (CQ)). Cu2+ was then used to seal the pores of the MSNs via chelation with the His-tag. The resultant nanoparticles showed pH-responsive drug release, and could effectively target tumor cells via the targeting effect of B3int. The presence of CP and Cu2+ permits reactive oxygen species to be generated inside cells; thus, the chemotherapeutic effect of CP is augmented by chemodynamic therapy. In vitro and in vivo experiments showed that the nanoparticles are able to effectively kill tumor cells. An in vivo cancer model revealed that the nanoparticles increase apoptosis in tumor cells, and thereby diminish the tumor volume. No off-target toxicity was noted. It thus appears that the functionalized MSNs developed in this work have great potential for targeted, synergistic anticancer therapies

EZH2 Regulates Protein Stability via Recruiting USP7 to Mediate Neuronal Gene Expression in Cancer Cells

Misexpression of chromatin modification factors and changed epigenetic modifications play crucial roles for tumorigenesis. Our previous studies demonstrated that inhibition of epigenetic modification enzymes EZH2, LSD1, DNMTs, and HDACs caused post-mitotic neuron-like differentiation in different cancer cells. However, how they regulate neuronal differentiation in cancer cells was unknown. Here, we show that EZH2, LSD1, DNMT1, and HDAC1 form interactions themselves, meanwhile, they also interact with SMAD proteins and β-CATENIN in cancer cells. Chemical inhibition of these enzymes leads to reduced level of proteins except HDAC1. The change in protein level and/or enzymatic activities further result in changed chromatin modifications on neuronal gene promoters, and activation of neuronal genes. Inhibition of these enzymes in neural progenitor cells (NPCs) also caused neuronal differentiation, similar to cancer cells. Particularly, EZH2 interacts with and required for the stability of LSD1, HDAC1, DNMT1, β-CATENIN, or SMAD2/4, via recruitment of deubiquitinase USP7. Reduced EZH2 leads to enhanced ubiquitination and degradation of these proteins, and decreased binding of LSD1, HDAC1, and DNMT1 to neuronal gene promoters, and lessened Wnt and TGFβ target gene activation. Hence, EZH2 sustains a series of proteins that promote tumorigenesis, in addition to its original function of histone methylation. Considering together with other studies, we conclude that these chromatin modification factors function in the same way in cancer cells as in neural progenitor/stem cells. The similarity between cancer cells and neural progenitor/stem cells provides an insight into the essence and unified framework for cancer initiation and progression, and are suggestive for novel strategies of cancer therapy

The Effect of Temozolomide/Poly(lactide-co-glycolide) (PLGA)/Nano-Hydroxyapatite Microspheres on Glioma U87 Cells Behavior

In this study, we investigated the effects of temozolomide (TMZ)/Poly (lactide-co-glycolide)(PLGA)/nano-hydroxyapatite microspheres on the behavior of U87 glioma cells. The microspheres were fabricated by the “Solid/Water/Oil” method, and they were characterized by using X-Ray diffraction, scanning electron microscopy and differential scanning calorimetry. The proliferation, apoptosis and invasion of glioma cells were evaluated by MTT, flow cytometry assay and Transwell assay. The presence of the key invasive gene, αVβ3 integrin, was detected by the RT-PCR and Western blot method. It was found that the temozolomide/PLGA/nano-hydroxyapatite microspheres have a significantly diminished initial burst of drug release, compared to the TMZ laden PLGA microspheres. Our results suggest they can significantly inhibit the proliferation and invasion of glioma cells, and induce their apoptosis. Additionally, αVβ3 integrin was also reduced by the microspheres. These data suggest that by inhibiting the biological behavior of glioma cells in vitro, the newly designed temozolomide/PLGA/nano-hydroxyapatite microspheres, as controlled drug release carriers, have promising potential in treating glioma

Analysis of Three Main Error Sources in Traditional Bladder Volume Formula and Development of a Computer Bladder Volume Calculation Program

This study analyzed three main sources of error in bladder volume calculation by traditional ultrasound bladder volume formula, which is most commonly used in clinic and built into most ultrasonic diagnostic apparatus. In order to solve these errors, we changed the traditional bladder volume formula to calculate bladder volume based on bladder axis to calculate volume based on bladder Section area, and corrected this formula according to actual clinical data to obtain a new formula, which is called the modified ellipsoidal trend formula. This formula can easily calculate the bladder volume manually during ultrasound examination of the bladder. Based on this formula, OpenCV function is applied to build a program for calculating bladder volume through two ultrasound images of bladder. The method is to calculate the total number of pixels in the contour of the bladder image by the program, and convert the number of pixels to area, and calculate the bladder volume using the modified ellipsoidal trend formula. This algorithm can be implanted into Ultrasonic diagnostic apparatus or ultrasound workstation to replace the traditional bladder volume formula. In this study, 122 ultrasound cases were used to test the accuracy of the program, and the results showed that the program was more accurate than the traditional bladder volume formula

Association between a novel mutation in SLC20A2 and familial idiopathic basal ganglia calcification.

Familial idiopathic basal ganglia calcification (FIBGC) is a rare, autosomal dominant disorder involving bilateral calcification of the basal ganglia. To identify gene mutations related to a Chinese FIBGC lineage, we evaluated available individuals in the family using CT scans. DNA was extracted from the peripheral blood of available family members, and both exonic and flanking intronic sequences of the SLC20A2 gene were amplified by PCR and then sequenced. Non-denaturing polyacrylamide gel electrophoresis (PAGE) was used to confirm the presence of mutations. Allele imbalances of the SLC20A2 gene or relative quantity of SLC20A2 transcripts were evaluated using qRT-PCR. A novel heterozygous single base-pair deletion (c.510delA) within the SLC20A2 gene was identified. This deletion mutation was found to co-segregate with basal ganglia calcification in all of the affected family members but was not detected in unaffected individuals or in 167 unrelated Han Chinese controls. The mutation will cause a frameshift, producing a truncated SLC20A2 protein with a premature termination codon, most likely leading to the complete loss of function of the SLC20A2 protein. This mutation may also lead to a reduction in SLC20A2 mRNA expression by approximately 30% in cells from affected individuals. In conclusion, we identified a novel mutation in SLC20A2 that is linked to FIBGC. In addition to the loss of function at the protein level, decreasing the expression of SLC20A2 mRNA may be another mechanism that can regulate SLC20A2 function in IBGC individuals. We propose that the regional expression pattern of SLC20A1 and SLC20A2 might explain the unique calcification pattern observed in FIBGC patients