Search

In order to improve the design ability of modified double base (MDB) propellant formulations, different intelligent algorithms were used for the formulation design and optimization of the burning rate property. By comparing several typical intelligent algorithms, including genetic algorithm (GA), differential evolution algorithm (DE), particle swarm optimization algorithm (PSO) and whale optimization algorithm (WOA), the intelligent formulation design and optimization of MDB propellants containing RDX were carried out. The results reveal that compared to the statistical optimization method, the intelligent optimization algorithm is simple to be operated and runs more quickly, while the 14 optimal formulations fitted by differential evolution algorithm have the best and more stable burning rate performance. Under the same pressures, the predicted burning rates of these 14 optimized formulations are significantly higher than the experimental values of the prepared formulations. Finally, a set of intelligent algorithm software for predicting the burning rate of modified double base propellants containing RDX is formed by coupling the difference algorithm with the support vector regression model. Based on the intelligent algorithm software, new formulations with the superior burning rate property could be deduced. [ABSTRACT FROM AUTHOR]

Objective To investigate the application of the comprehensive use of multiple genetic markers in full and half sibling relationship testing through the identification of a case of suspected sibling relationship. Methods Genomic DNA were extracted from bloodstain samples from 4 subjects (ZHANG-1, ZHANG-2, male; ZHANG- 3, ZHANG-4, female). Autosomal STR loci, X- STR, Y- STR loci and polymorphisms of mtDNA HV- I and H were genotyped by EX20 STR kit, X19 kit, Data Y24 STR kit, and Sanger sequencing, respectively. Results According to autosomal STR based IBS scoring results, full sibling relationships were indicated among ZHANG-2, ZHANG-3 and ZHANG-4, but those were not indicated between ZHANG-1 and ZHANG-2 or ZHANG-3 or ZHANG-4. According to autosomal STR based FSI and HSI, with ITO method and discriminant function method, full sibling relationships among ZHANG- 2, ZHANG- 3 and ZHANG- 4 were indicated, and half sibling relationships between ZHANG-1 and ZHANG-2 or ZHANG-3 or ZHANG-4 were also indicated. X-STR and mtDNA sequencing results showed that all the 4 samples came from a same maternal line, and Y-STR results showed that ZHANG-1 and ZHANG- 2 did not come from a same paternal line, which supported the half sibling relationship between ZHANG-1 and ZHANG-2 or ZHANG-3 or ZHANG-4, verified by parental genotype reconstruction based on autosomal STR genotyping. Conclusion For the identification of sibling relationships, it is effective to have reliable results with the mutual verification and support of multiple genetic markers (autosomal STR, sex chromosomal STR and mtDNA sequence) and calculations ( IBS, ITO, discriminant function method and family reconstruction). [ABSTRACT FROM AUTHOR]

The effects of grazing on spatial distribution relationships of constructive species (Stipa breviflora) and dominant species (Cleistogenes songorica and Allium polyrhizum) in the desert steppe were analyzed by different analysis methods. The results showed that the landscape characteristic of S. breviflora + C. songorica + A. polyrhizum community was mainly affected by soil properties and inherent properties of populations. The spatial distribution variability influenced by continuous grazing (CG) was in order of A. polyrhizum > C. songorica > S. breviflora. The influence of CG upon the density of S. breviflora and A. polyrhizum? was notable, while little influence upon the density of C. songorica was observed. S. breviflora density increased with the increasing C. songorica density in CG area, whereas it increased firstly and then decreased with the increasing C. songorica density in enclosed area (CK). S. breviflora density decreased with the increasing A. polyrhizum density in CG and CK area. It was concluded that there was density effect for plant interspecific relationships which could disappear with the presence of outside interference. Plant interspecific relationships were multiple with the difference in populations or interference conditions. [ABSTRACT FROM AUTHOR]

Hemp powder and PVDF blended approach were used to modify PVDF membrane, then the blend interlayer film microstructure and thermal properties, mechanical properties as well as peel strength between CFRP and other properties were tested, and the influence of hemp flour content on the blend membrane performance was studied. Experimental results show that with the increase of the mass fraction of hemp powder, blend membrane surface finish lower, more irregular cross-section structure, density and thickness increase, the blend film becomes brittle, while mechanical properties dropped significantly; with the increase of the mass fraction of hemp powder, the inter-layer blend membranes with CFRP / wood composites, interlaminar strength firstly increases and then decreases, when the mass fraction of hemp powder is 6%, the maximum interlaminar strength value is 0.36 N/mm. [ABSTRACT FROM AUTHOR]

The effects of grazing on spatial distribution relationships of constructive species (Stipa breviflora) and dominant species (Cleistogenes songorica and Allium polyrhizum) in the desert steppe were analyzed by different analysis methods. The results showed that the landscape characteristic of S. breviflora + C. songorica + A. polyrhizum community was mainly affected by soil properties and inherent properties of populations. The spatial distribution variability influenced by continuous grazing (CG) was in order of A. polyrhizum > C. songorica > S. breviflora. The influence of CG upon the density of S. breviflora and A. polyrhizum was notable, while little influence upon the density of C. songorica was observed. S. breviflora density increased with the increasing C. songorica density in CG area, whereas it increased firstly and then decreased with the increasing C. songorica density in enclosed area (CK). S. breviflora density decreased with the increasing A. polyrhizum density in CG and CK area. It was concluded that there was density effect for plant interspecific relationships which could disappear with the presence of outside interference. Plant interspecific relationships were multiple with the difference in populations or interference conditions.

Objective: To investigate the DNA damage of splenic lymphocytes in pregnant mice exposed to carbon disulfide (CS2) in the implantation phase and to explore the mechanism of abnormal implantation induced by CS2 from the perspective of immune injury., Methods: Mice were exposed to CS2 at different doses or at different time points in the implantation phase to establish model 1 and model 2. For model 1, mice were assigned to four groups to receive a single intraperitoneal injection of low-dose CS2 (0.1 LD50, 157.8 mg/kg), middle-dose CS2 (0.2 LD50, 315.7 mg/kg), and high-dose CS2 (0.4 LD50, 631.4 mg/kg) as well as an equal volume of olive oil (control) on gestational day (GD) 4. For model 2, mice were assigned to four groups to receive a single intraperitoneal injection of CS2 (0.4 LD50, 631.4 mg/kg) or an equal volume of olive oil (control) on GD3, GD4, GD5, and GD6. At the end, single cell suspension of splenic lymphocytes was prepared. Cell viability was measured by trypan blue staining, and the DNA damage of splenic lymphocytes was evaluated by alkaline single cell gel electrophoresis assay., Results: The middle-dose and high-dose exposure groups showed significantly more DNA damage of splenic lymphocytes than the control group (P < 0.01); there was significant regression relationship between indicators of DNA damage and exposure doses (P < 0.01). The GD3, GD4, GD5, and GD 6 exposure groups showed significantly more DNA damage of splenic lymphocytes than the control group (P < 0.01), and the GD 4 exposure group had the most DNA damage., Conclusion: Exposure to CS2 in the implantation phase can induce DNA damage of splenic lymphocytes in pregnant mice, and the DNA damage was aggravated with the increase in CS2 concentration. GD4 may be the sensitive time point for DNA damage of splenic lymphocytes induced by CS2 in pregnant mice.

Objective: To evaluate the effects of carbon disulfide (CS(2)) exposure during peri-implantation on the estrogen receptor-α (ER-α) expression in the uterus and serum level of estradiol (E(2)) in pregnant mice, and to explore the mechanism of embryotoxicity of CS(2)., Methods: Healthy female mice were exposed to a single dose of CS(2) (631.4 mg/kg) or olive oil (solvent control) on gestational day (GD)3, GD4, GD5, or GD6. At different time points after exposure, the serum E(2) levels of the pregnant mice were measured by enzyme-linked immunosorbent assay, and the expression levels of ER-α in the uterus were measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot., Results: Compared with the control group, the GD3, GD4, GD5, and GD6 exposure groups showed significantly decreased serum E(2) levels on day 7 of gestation (P < 0.05); the GD3 and GD5 exposure groups showed significantly decreased serum E(2) levels on day 6 of gestation (P < 0.05). The expression level of ER-α in the GD 4 exposure group was 23.6% lower than that in the control group on day 5 of gestation, and the expression level of ER-α in the GD 5 exposure group was 72.9% lower than that in the control group on day 6 of gestation (P < 0.05); the GD 3 and GD 6 exposure groups showed lower expression levels of ER-α than the control group at any time point, but no significant difference was found (P > 0.05)., Conclusion: CS(2) exposure during peri-implantation can reduce the ER-α expression in the uterus and the serum level of E(2) in pregnant mice, which may be one of the mechanisms of embryotoxicity of CS(2).

Objective: To observe the effect of carbon disulfide (CS(2)) on the expression of matrix metalloproteinase (MMP)-2, MMP-9 in mouse embryo and uterus tissues and to explore the mechanism of embryo toxicity induced by CS(2)., Methods: At the phases of follicular development and embryonic implantation which was subdivided into early-implantation phase and late-implantation phase, mice were intraperitoneally exposed to CS(2) (the dosage was 631.4 mg/kg, and the volume was 0.1ml/10 g body weight) for 2 consecutive days. All indicators were got at the ninth day in gestation, and the expression of MMP-2 and MMP-9 in embryo and uterus tissues was analyzed by gelatin zymography., Results: The number of implanted embryos significantly decreased after exposure at late-implantation phase (16.000 ± 12.166) compared with those of the control (30.700 ± 5.599, P < 0.05). Expression of MMP-2 and MMP-9 in embryos declined obviously at the three reproductive phases (P < 0.01), and the levels of MMP-2 and MMP-9 expression in embryos at the phases of late-implantation phase (0.6837 ± 0.0929, 0.7309 ± 0.0822) and follicular development (0.6222 ± 0.0997, 0.7520 ± 0.1068) were much lower than those of the control (1.0000 ± 0.0710, 1.0000 ± 0.0413, P < 0.01). Expression of MMP-2 and MMP-9 in uterus significantly increased at the phase of late-implantation (1.3153 ± 0.3032, 5.0210 ± 4.0307) compared with those of the control (1.0000 ± 0.1771, 1.0000 ± 0.0996, P < 0.01)., Conclusion: Embryo toxicity of CS(2) is more obvious at the phase of late-implantation. Exposure to CS(2) disturbs expression of MMP-2 and MMP-9 in embryo and uterus tissues, which might be one of the important factors contributed to embryo toxicity induced by CS(2).

Objective: To analyze the stress distribution in all-ceramic crowns when it was subjected to load., Methods: A 3D numerical model of the all-ceramic crown of the right mandibular first molar was generated from scanned CT images. Finite element analysis (FEA) was used to evaluate the stress distribution in the all-ceramic crown when it was subjected to 5 load conditions., Results: Stress distributions under 5 loading conditions were obtained. Stress concentrations were generally found near the loading areas at the veneer and at the lower surface of the core beneath the loading areas. In the 5 loading conditions, it was found that when the crown was loaded with vertical concentrated load, the tensile stresses around the shoulder areas were uniform, while stress concentration with maximum of 32.25 MPa was found at the shoulder areas in lingual-buccal direction when loads were applied at an angle of 10 degrees with the tooth axis on the buccal side. The masticatory load which was applied at 20 degrees with the tooth axis on the buccal side would cause stress concentration at the shoulder in mesial-distal direction. The maximum value could reach 11.29 MPa., Conclusions: The occlusal surface of the all-ceramic crown must be trimmed to increase multiple contact zones with the opposite surfaces in antagonist teeth to avoid excessive concentrated stress that may cause crown failure.

The purpose of this study was to explore the mechanism of CAG regimen eliminating T-cell acute lymphoblastic leukemia (T-ALL) A3 cell line and evaluate the role of G-CSF/G-CSFR system in this process. The expression levels of G-CSFR on the A3 cell membrane were detected by flow cytometry. Cell cycle changes of A3 cells treated with different concentrations of G-CSF for 48 hours were examined by propidium iodide staining method. The inhibition and apoptosis rates of A3 cells treated with various combinations of G-CSF, cytarabine (Ara-C), aclarubicin (ACR) were analyzed by Cell Counting Kit and AnnexinV Kit, respectively. The results indicated that the expression level of G-CSFR on A3 cells was 94.2%. The proportion of A3 cells in S-phase rose concomitantly with the increasing of G-CSF concentrations within 0-20 ng/ml. After incubation with Ara-C and G-CSF for 48 hours, A3 cells were inhibited more obviously compared with incubation with Ara-C alone (p<0.05, Ara-C 10(-5) mol/L and 10(-6) mol/L). After incubation with Ara-C, ACR and G-CSF for 48 hours, the apoptotic rate of A3 cells was much more than that after incubation with Ara-C and ACR. It is concluded that the expression level of G-CSFR on A3 cells is high, G-CSF/G-CSFR system has a synergetic effect on eliminating A3 cells when administrated simultaneously with chemical agents. This effect is caused through driving more cells from G0 phase into S phase, increasing sensitivity of A3 cells to chemical drugs and inducing cell apoptosis which may be one of the mechanisms of CAG regimen eliminating A3 cells.