岩土工程中位移量测的随机逆反分析

本文考虑了岩土工程中量测位移及介质力学模型的随机不确定性，基于随机有限元和特征函数法分析，提出了反演岩土体初始地应力场、介质力学特性参数的均值及多阶矩的随机逆反分析方法。研究结果表明随机逆反分析更能符合实际不确定岩土工程的要求。

岩土工程逆反分析的进化神经网络研究

逆反分析实质为系统的逆辨识过程,对此采用神经网络描述比较合理有效。基于提出的网络权值及其结构同时进化的新型进化神经网络模型,进行了岩土工程逆反分析的研究,并用一个算例进行了效果验证。结果证明反分析精度较高,其效果良好。由研究得到以下结论:网络训练样本应由正分析得到,且应采用正交实验设计进行样本选取;神经网络逆反分析时多参数反演的精度低于单参数反演。

海水入侵三维含水层渗透系数的BP网络逆反分析

为研究复杂地质体海水入侵渗透系数的不确定性,将非线性动力学神经网络用于海水入侵的三维含水层参数的逆反分析,建立了基于监测水头值的海水入侵渗透系数直接识别方法.采用正交设计试验方法进行三维数值试验产生代表性的样本数据,通过误差逆传播学习算法建立多层的神经网络模型,表示观测水头和渗透系数隐式的复杂非线性映射关系,通过观测水头信息直接预测含水层渗透系数.该方法可利用现有的海水入侵三维有限元模拟程序.算例表明该法具有良好的分析精度,可满足工程要求.

岩体材料参数反分析的有限元方法研究

本文主要研究讨论了工程反分析和岩土工程中关于求解材料力学参数的方法,在岩土工程中称为反分析法。一般来说,反分析问题比正分析问题要困难得多。经验表明,有限元法是反分析的有力工具。反分析目前有多种方法,本文着重讲述了逆反分析法。

浅埋风化岩质隧道初支护后黏弹性变形性态分析

为分析浅埋风化岩质隧道围岩初支护后变形随时间变化的黏弹性效应,首先采用逆反分析法推导出圆形隧道围岩的等效弹性模量和等效侧压力系数的解析解;然后结合具体工程实践,选择典型断面采集围岩初支护后的位移实测数据,采用数理统计方法,获取该类型隧道围岩初支护后的等效侧压力系数与等效弹性模量之比随时间的变化规律,建立围岩初支护后的黏弹性模型,研究隧道围岩初支护后变形随时间变化的黏弹性效应。研究结果表明:浅埋风化岩质隧道围岩初支护后在无降雨等外部因素作用下等效侧压力系数与等效弹性模量之比随时间呈Monomolecular增长模式并最终稳定于某一常数,即围岩变形随时间变化的黏弹性效应也符合此规律,并且其应变与等效侧压力系数成反比变化;在围岩刚度较大和地下水活动较弱的地段,初支护后围岩变形将较快趋于稳定。

Reverse Engineering Analysis Based on Differential Fault Analysis Against Secret S- boxes

To evaluate the security of cipher algo- rithrrs with secret operations, we built a new reverse engineering analysis based on Differential Fault Analysis （DFA） to recover the secret S-boxes in Secret Private Network （SPN） and Feistel structures, which are two of the most typical structures in block ciphers. This paper gives the general definitions of these two structures and proposes the reverse engineering analysis of each structure. Furthermore, we evaluate the complexity of the proposed reverse analyses and theoretically prove the effectiveness of the reverse method. For the Twoflsh-like and AES-like algorithrm, the experimental results verify the correctness and efficiency of the reverse analysis. The proposed reverse analysis can efficiently recover the secret S-boxes in the encryp＇don algorithms writh SPN and Feistel structures. It can successfully recover the Twoflsh- like algorithm in 2.3 s with 256 faults and the AES- like algorithm in 0.33 s with 23 faults.

15-PGDH is reduced and induces apoptosis and cell cycle arrest in gastric carcinoma

AIM: To investigate the expression of 15-hydroxyprostaglandin dehydrogenase (15-PGDH) in human gastric cancer and it's mechanism in apoptosis and cell cycle arrest. METHODS: Expression of 15-PGDH mRNA and protein was examined by immunohistochemistry, immunocytochemistry, reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting in tissue from human gastric cancer, gastric precancerous state (gastric polyps and atrophic gastritis), normal stomach, and gastric cancer cell lines. The relationship between gastric cancer, gastric precancerous state and 15-PGDH expression was determined. The association between expression of 15-PGDH and various clinicopathological parameters in gastric cancer was evaluated. Human gastric cancer cell line SGC-7901 was transfected with 15-PGDH expression plasmids. The effect of 15-PGDH on the cell cycle was examined by flow cytometry. The effect of 15-PGDH on apoptosis was examined by transmission electron microscopy, flow cytometry and transferasemediated nick end labeling (TUNEL) assay. Expression of cell cycle (p21, p27, p16 and p53) and apoptosis (Survivin, BCL-2, BCL-XL, BAK and BAX) genes was analyzed by RT-PCR. RESULTS: Expression of 15-PGDH mRNA and protein in human gastric cancer tissues was significantly lower than in normal gastric tissues (P < 0.01). Expression in human gastric cancer cell lines MKN-28 and MKN-45 was reduced, and absent in SGC-7901 cells (P < 0.05). Reduction of 15-PGDH expression was also found in precancerous tissues, such as gastric polyps and atrophic gastritis (P < 0.01). There was a significant difference in expression of 15-PGDH among various gastric cancer pathological types (P < 0.05), with or without distant metastasis (P < 0.05) and different TNM stage (P < 0.01). Flow cytometry demonstrated a significant increase in apoptotic cells in SGC-7901 cells transfected with pcDNA3/15-PGDH plasmid for 24 and 48 h (P < 0.01), and an increased fraction of sub-G1 phase after transfection (P < 0.05). TUNEL assay showed an increased Apoptotic Index in cells overexpressing 15-PGDH (P < 0.01). After transfection, expression of proapoptotic genes, such as BAK (P < 0.05), BAX and p53 (P < 0.01), was increased. Expression of antiapoptotic genes was decreased, such as Survivin, BCL-2 and BCL-XL (P < 0.01). Expression of cyclin-dependent kinase inhibitors p21 and p16 (P < 0.01) was significantly upregulated in cells overexpressing 15-PGDH. CONCLUSION: Reduction of 15-PGDH is associated with carcinogenesis and development of gastric carcinoma. 15-PGDH induces apoptosis and cell cycle arrest in SGC-7901 cells.

Cloning,characterization,and expression analysis of the DEAD-box family genes,Fc-vasa and Fc-PL10a,in Chinese shrimp (Fenneropenaeus chinensis)

RNA helicases of the DEAD-box and related families are involved in various cellular processes including DNA replication, DNA repair, and RNA processing. However, the function of DEAD-box proteins in aquaculture species is poorly understood at molecular level. We obtained the full-length cDNA sequences of two genes encoding helicase-related proteins, Fc-vasa and Fc-PL10a, from the testes of Chinese shrimp, Fenneropenaeus chinensis. The two predicted amino acid sequences contain all the conserved motifs characterized by the DEAD-box family and several RGG repeats in the N-terminal regions. Homology and phylogenetic analyses indicate that they belong to the vasa and PLIO subfamilies. The three-dimensional structures of the two proteins were predicted with a homology modeling approach. Both core proteins consist of two tandem RecA-like domains similar to those of the DEAD-box RNA helicase. Using reverse transcription-polymerase chain reaction （RT-PCR） and real-time PCR we found that Fc-vasa was expressed specifically in the adult gonads. Transcription decreased in the ovary but increased in the testis during gonadal development. Fc-PL10a expression was widely distributed in the tissues we examined. Using in situ hybridization, we demonstrated that the Fc-vasa transcript is localized to the cytoplasm of the spermatogonia and oocytes. Thus, our results suggest that Fc-wasa plays an important role in germ-line development, and has utility as a germ cell lineage marker which will help to generate new insight into the origin and differentiation of germ cells as well as the regulation of reproduction in F. chinensis.

Na^+/K^+-ATPase α-subunit in swimming crab Portunus trituberculatus: molecular cloning, characterization, and expression under low salinity stress

Na^＋/K^＋-ATPases are membrane-associated enzymes responsible for the active transport of Na^＋ and K^＋ ions across cell membranes, generating chemical and electrical gradients. These enzymes＇ α-subunit provides catalytic function, binding and hydrolyzing ATP, and itself becoming phosphorylated during the transport cycle. In this study, Na^＋/K^＋-ATPase α-subunit eDNA was cloned from gill tissue of the swimming crab Portunus trituberculatus by reverse-transcription polymerase chain reaction （RT-PCR） and rapid amplification of eDNA end methods. Analysis of the nucleotide sequence revealed that the eDNA had a full-length of 3 833 base pairs （bp）, with an open reading frame of 3 120 bp, 5＇ untranslated region （UTR） of 317 bp, and 3＇ UTR of 396 bp. The sequence encoded a 1 039 amino acid protein with a predicted molecular weight of 115.57 kDa and with estimated pI of 5.21. It was predicted here to possess all expected features of Na^＋/K^＋-ATPase members, including eight transmembrane domains, putative ATP-binding site, and phosphorylation site. Comparison of arnino acid sequences showed that the P. tritubereulatus α-subunit possessed an overall identity of 75%-99% to that of other organisms. Phylogenetic analysis revealed that this α-subunit was in the same category as those of crustaceans. Quantitative real-time RT-PCR analysis indicated that this α-subunit＇s transcript were most highly expressed in gill and lowest in muscle. RT-PCR analysis also revealed that α-subunit expression in crab gill decreased after 2 and 6 h, but increased after 12, 24, 48, and 72 h. In addition, α-subunit expression in hepatopancreas of crab decreased after 2-72 h. These facts indicated that the crab＇s Na^＋/K^＋-ATPase α-subunit was potentially involved in the observed acute response to low salinity stress.

XAF1 is frequently methylated in human esophageal cancer

AIM： To explore epigenetic changes in the gene encod- ing X chromosome-linked inhibitor of apoptosis-associ- ated factor 1 （XAF1） during esophageal carcinogenesis. METHODS： Methylation status of XAF1 was detected by methylation-specific polymerase chain reaction （MSP） in four esophageal cancer cell lines （KYSE30, KYSE70, BICl and partially methylated in TE3 cell lines）, nine cases of normal mucosa, 72 cases of pri- mary esophageal cancer and matched adjacent tissue. XAF1 expression was examined by semi-quantitative reverse transcriptional polymerase chain reaction and Western blotting before and after treatment with 5-aza- deoxycytidine （5-aza-dc）, a demethylating agent. To investigate the correlation of XAF1 expression and methylation status in primary esophageal cancer, immu- nohistochemistry for XAF1 expression was performed in 32 cases of esophageal cancer and matched adjacent tissue. The association of methylation status and clini-copathological data was analyzed by logistic regression. RESULTS： MSP results were as follows： loss of XAF1 expression was found in three of four esophageal cell lines with promoter region hypermethylation （com- pletely methylated in KYSE30, KYSE70 and BIC1 cell lines and partially in TE3 cells）; all nine cases of normal esophageal mucosa were unmethylated; and 54/72 （75.00%） samples from patients with esophageal can- cer were methylated, and 25/72 （34.70%） matched adjacent tissues were methylated （75.00% vs 34,70%, z2 = 23.5840, P = 0.000）. mRNA level of XAF1 mea- sured with semi-quantitative reverse transcription poly- merase chain reaction was detectable only in TE3 cells, and no expression was detected in KYSE30, KYSE70 or BIC1 cells. Protein expression was not observed in KYSE30 cells by Western blotting before treatment with 5-aza-dc. After treatment, mRNA level of XAF1 was detectable in KYSE30, KYSE70 and BIC1 cells. Protein expression was detected in KYSE30 after treatment with 5-aza-dc. Immunohistochemistry was performed on 32 cases of esophageal cancer and adjacent tissue, and demonstrated XAF1 in the nucleus and cytoplasm. XAF1 staining was found in 20/32 samples of adjacent normal tissue but was present in only 8/32 samples of esophageal cancer tissue （Z2= 9.143, P = 0.002）. XAF1 expression was decreased in cancer samples compared with adjacent tissues. In 32 cases of esophageal can- cer, 24/32 samples were methylated, and 8/32 esopha- geal cancer tissues were unmethylated. XAF1 staining was found in 6/8 samples of unmethylated esophageal cancer and 2/24 samples of methylated esophageal cancer tissue. XAF1 staining was inversely correlated with XAF1 promoter region methylation （Fisher＇s exact test, P = 0.004）. Regarding methylation status and clinicopathological data, no significant differences were found in sex, age, tumor size, tumor stage, or metas- tasis with respect to methylation of XAF1 for the 72 tis- sue samples from patients with esophageal cancer. CONCLUSION： XAF1 is frequently methylated in eso- phageal cancer, and XAF1 expression is regulated by promoter region hypermethylation.

Virus-induced gene silencing and its application in plant functional genomics

Virus-induced gene silencing is regarded as a powerful and efficient tool for the analysis of gene function in plants because it is simple, rapid and transformation-free. It has been used to perform both forward and reverse genetics to identify plant functional genes. Many viruses have been developed into virus-induced gene silencing vectors and gene functions involved in development, biotic and abiotic stresses, metabolism, and cellular signaling have been reported. In this review, we discuss the development and application of virus-induced gene silencing in plant functional genomics.

Artemisinin ameliorated proteinuria in rats with adriamycin-induced nephropathy through regulating nephrin and podocin expressions

OBJECTIVE:To investigate the effects of artemisinin against proteinuria and glomerular filtration barrier damage in rats with adriamycin-induced nephropathy,and the potential mechanism underpinned the action.METHODS:Forty adriamycin rats were randomly divided into two groups with the ratio of 1︰3;the small-number group served as control group(n=10),and the rats in the large-number group were treated with adriamycin to induce nephropathy;then they were further randomly assigned into 3subgroups:benazepril group(n=10),artemisiningroup(n=10),and adriamycin group(n=10).The benazepril group and artemisinin group were treated with benazepril suspl(5.0 mg/kg daily)and artemisinin suspl(150 mg/kg daily)respectively after being modeled;those in the control group and adriamycin group were intragastrically administered an equivalent volume of distilled water every day.The treatment after model establishment lasted for a total of 4 weeks.The 24 h uric protein,blood biochemicals,renal pathological changes,renal ultrastrutural changes,Nephrin and Podocin proteins and gene expressions were measured by Coomassie brilliant blue assay,completely automatic biochemical analyzer,light microscope,electron microscopy,Western blot and reverse transcription polymerase chain reaction,respectively.RESULTS:The rats in adriamycin group showed a significant increase in 24 h uric protein excretion,serum total cholesterol(TC),triglyceride(TG),blood urea nitrogen(BUN),serum creatinine(Scr)and decrease in albumin(Alb)(P<0.05 or P<0.01).Compared with adriamycin group,artemisinin could reduce uric protein excretion,decrease the serum TC,TG elevation,increase the serum Alb level,up-regulate the expressions of Nephrin and Podocin(P<0.05 or P<0.01),but no statistical significance effects on the levels of BUN,Scr in artemisinin group(P>0.05).The renal pathological and ultrastrutural observation indicate that artemisinin could attenuate the severity of foot process effacement and fusion in the nephropathic rats.CONCLUSION:Artemisinin might have an effect on the nephropathy in rats caused by adriamycin,which may be at least partly correlated with attenu-ation of the severity of foot process effacement and fusion,up-regulation of the expressions of Nephrin and Podocin in the glomeruli in the rats.

Effect of quercetin on secretion and gene expression of leptin in breast cancer

OBJECTIVE: To investigate the possible inhibitory action of pure quercetin on secretion and gene expression of leptin in the T47 D breast cancer cell line.METHODS: In this experimental study, T47 D cells were cultured in monolayers in RPMI 1640. IC50 was determined by MTT(3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay after 24 h treatment at different concentrations of quercetin.The levels of leptin gene expression were measured by reverse-transcription real-time polymerase chain reaction(PCR). Secreted leptin was measured in the supernatant of cells by an enzyme-linked immuno sorbent assay.RESULTS: Analysis of MTT assay data showed that quercetin has a cytotoxic effect on T47 D breast cancer cells with 40 μM IC50 after 24 h exposure. Dataanalysis of real-time PCR showed that with increases in quercetin concentration, a decreasing trend was seen in m RNA levels of leptin of treated cells compared with the control cells(P < 0.05). Also,measurement of secreted leptin in the culture media showed a similar decreasing trend in the amount of leptin protein in the treated cells compared with the control cells(P < 0.05).CONCLUSION: Quercetin significantly inhibits the growth of T47 D cells through inhibition of leptin secretion and gene expression in T47 D breast cancer cells. Therefore, it might be an alternative approach to breast cancer therapy through leptin targeting.