Search

Based on initial discontinuity state (IDS) of material, this paper presents a preliminary analytical model which was developed to evaluate the effect of exfoliation corrosion on the residual fatigue life of upper wing skins. A life prediction was then carried out using constant amplitude compression dominated loading for various exfoliation corrosion levels by AFGROW, and the prediction agreed reasonably with the available test data. The result suggest that exfoliation can be treated as a process zone located initially at a surface, and then at the base of an evolving general stress concentration representing the loss of material in the exfoliation region. The major effect of the exfoliation corrosion on fatigue life is to cause a dramatic reduction in life with small corrosion depths, and most of the fatigue effect is associated with the introduction of small pits, rather than more general stress concentration associated with the bulk of the exfoliation attack. But the effect of pit on fatigue life is gradually reduced with increasing pit size. A pit with a constant depth can be applied to the model described in this paper for long exposure structure. A preliminary recommendation for the pit depth is about 0.3mm for LY12CZ.

The fault tree analysis is a widely used method for evaluation of systems reliability and safety. Dynamic fault tree (DFT) extend traditional FT by defining additional gates called dynamic gates to model these complex interactions. Markov models are used in solving dynamic gates. However, state space becomes too large for calculation with Markov models when the number of gate inputs increases. In addition, Markov model is applicable for only exponential failure and repair distributions. But in engineering, the failure mode is mostly obeyed to weibull distribution for mechanism and electronic units. Combined the weibull distribution and Markov model, this paper presents dynamic fault tree quantitative analysis method based on weibull distribution.

According to standard test method for fatigue crack growth rates of metallic materials, the crack growth rate of 30NCD16 at three stress ratio (R=0.1, 0.3 and 0.5) were measured. Based on linear elasticity fracture mechanics theory, the fatigue crack growth rate was studied through the nonlinear least squares fitting method. The Paris model parameters at steady growth region and near threshold growth region and NASGRO model parameters were obtained. The effective stress intensity factors versus curves at three stress ratios were determined by crack closure effect. The results show that the Paris equation can preferably describe relations at steady growth region. At this region the model parameter m lies 2.5-4. This result is consistent with the known statistical facts of most metallic materials. NASGRO equation can preferably describe relations from near threshold growth region to high values region. all the test data at three stress ratio was able to correlate and . Crack closure was the major factor in correlating stress ratio and crack growth rate, the degree of crack closure weaken with increasing stress ratio.

The retina is a specialized sensory organ, which is essential for light detection and visual formation in the human eye. Inherited retinal degenerations are a heterogeneous group of eye diseases that can eventually cause permanent vision loss. UPR (unfolded protein response) and ER (endoplasmic reticulum) stress plays an important role in the pathological mechanism of retinal degenerative diseases. mTOR (the mammalian target of rapamycin) kinase, as a signaling hub, controls many cellular processes, covering protein synthesis, RNA translation, ER stress, and apoptosis. Here, the hypothesis that inhibition of mTOR signaling suppresses ER stress-induced cell death in retinal degenerative disorders is discussed. This review surveys knowledge of the influence of mTOR signaling on ER stress arising from misfolded proteins and genetic mutations in retinal degenerative diseases and highlights potential neuroprotective strategies for treatment and therapeutic implications.

ObjectiveAldehyde dehydrogenase (ALDH) has recently been reported as a marker of cancer stem-like cells in ovarian cancer. However, the prognostic role of ALDH in ovarian cancer still remains controversial. In this study, we aimed to evaluate the association between the expression of ALDH and the outcome of ovarian cancer patients by performing a meta-analysis.MethodsWe systematically searched for studies investigating the relationships between ALDH expression and outcome of ovarian cancer patients. Only articles in which ALDH expression was detected by immunohistochemical staining were included. A meta-analysis was performed to generate combined hazard ratios (HRs) with 95% confidence intervals (CIs) for overall survival (OS) and disease-free survival (DFS).ResultsA total of 1,258 patients from 7 studies (6 articles) were included in the analysis. Our results showed that high ALDH expression in patients with ovarian cancer was associated with poor prognosis in terms of Os (HR, 1.25; 95% CI, 1.07-1.47; P = 0.005) and DFS (HR, 1.58; 95% CI, 1.00-2.49; P = 0.052), though the difference for DFS was not statistically significant. In addition, there was no evidence of publication bias as suggested by Begg's and Egger's tests (Begg's test, P = 0.707; Egger's test, P = 0.355).ConclusionThe present meta-analysis indicated that elevated ALDH expression was associated with poor prognosis in patients with ovarian cancer.

Senescence marker protein 30 (SMP30), a hepatocellular carcinoma (HCC) associated antigen, was earlier shown by our research group to be highly expressed in HCC paracancerous tissues, but have low levels in HCC tissues. In order to detect anti-SMP30 antibody in serum of HCC patients, we established pET30a-SMP30 and pColdIII-SMP30 expression systems in Escherichia coli. However, the expression product was mainly in the form of inclusion bodies. In this research, we used several combinations of chaperones, four molecular chaperone plasmids with pET30a-SMP30 and five molecular chaperone plasmids with pColdIII-SMP30 to increase the amount of soluble protein. Results showed that co-expression of HIS-SMP30 with pTf16, combined with the addition of osmosis-regulator, and a two-step expression resulted in the highest enhancement of solubility. A total of 175 cases of HCC serum were studied by ELISA to detect anti- SMP30 antibody with recombinant SMP30 protein. Some 22 were positive and x 2 two-sided tests all showed P>0.05, although it remained unclear whether there was a relationship between positive cases and clinical diagnostic data.

To clone and prokaryotically express the EGF and SP domain proteins of human mannan-binding lectin associated serine protease-2 (MASP-2), and prepare their polyclonal antibodies and analyze their immunogenicity.The cDNA of human MASP-2 was transcripted reversely from total RNA extracted from human fetal liver tissue, and then EGF and SP domain genes of MASP-2 were amplified from the cDNA by PCR. The EGF and SP fragment domain genes were cloned into pGEX-6P-2 expression vector and induced by IPTG to express GST fusion protein. The BALB/c mice were immunized with the purified fusion proteins to generate polyclonal antibodies. The specificity of the polyclonal antibodies was analysed with Western blotting, and the titer was determined by indirect ELISA.We successfully constructed the recombinant pGEX-6P-2-EGF and pGEX-6P-2-SP and induced the expressions of the GST-EGF and GST-SP fusion proteins. The specificity of the polyclonal antibodies was higher, and had no cross reaction with other proteins. Indirect ELISA showed that the titer of anti-EGF antibody was more than 1:32 000 and anti-SP antibody was more than 1:40 000.The polyclonal antibodies of the EGF and SP domain proteins we successfully obtained were of higher specificity and titer, which provides the basis for further research on MASP-2.

Xanthomonas oryzae pv. oryzicola is an important bacterial pathogen responsible for outbreaks of bacterial leaf streak (BLS) on rice, mostly occurring in Asia and parts of Africa. To better monitor epidemics and assess population structures, efficient tools that allow the precise identification and diagnosis of pathogenic populations are needed. In this study, we explored variable numbers of tandem repeats (VNTR) as a fast, reliable, and cost-effective molecular typing tool. Screening of three X. oryzae pv. oryzicola genome sequences (Philippine strain BLS256, Chinese strain GX01, and Malian strain MAI10) predicted 28 candidate VNTR loci. Primer pairs for polymerase chain reaction (PCR) amplification of all 28 loci were designed and applied to a panel of 20 X. oryzae pv. oryzicola strains originating from Asia and Africa. Sequencing of PCR amplicons revealed 25 robust and polymorphic VNTR loci that are shared among Asian and African X. oryzae pv. oryzicola strains. A dendrogram constructed from 25 VNTR loci indicated that most Asian strains are clearly discriminated from African strains. However, in agreement with previous reports, one strain from Mali is related to Asian strains, pointing to a possible introduction of Asian strains to the African continent. The new VNTR-based tool described here is useful for studies of population structures and epidemiological monitoring of X. oryzae pv. oryzicola.

Virulence assays and DNA polymorphism analyses were used to characterize 33 Xanthomonas oryzae pv. oryzae (Xoo) strains collected from the coastline region of Fangchenggang city in China. Two new pathogenic races (FXP1 and FXP2), were determined by leaf-clipping inoculation of 12 near-isogenic International Rice-Bacterial Blight (IRBB) rice lines, each containing a single resistance gene. Race FXP1 consisted of twenty-eight strains that were incompatible on IRBB5 and IRBB7, while race FXP2 included five strains that were incompatible on IRBB5 and IRBB7 and moderately virulent on IRBB8 containing the xa8 gene. Restriction fragment length polymorphism (RFLP) analysis revealed that each probe of avrXa10 and IS1112 resolved two haplotypes. In a dendrogram generated from the combined RFLP data, the 33 Xoo strains were resolved into two clusters. There was a weak correlation (r = 0.53) between race and haplotype. All of the rice cultivars planted in the coastline region of Fangchenggang city were susceptible to the representative Xoo strains tested above. However, we found that four rice cultivars used as breeding materials in the laboratory could fully resist infection by the Xoo strains, suggesting that the isolated Xoo strains could be used to detect resistant rice cultivars suitable for planting in the local rice field.

The posttranscriptional RNA editing by the type 1 adenosine deaminase acting on RNAs (ADAR1), expressed as p110 and p150 isoforms, is important for both physiological and pathological processes. Their expression and significance in leukemias remain unknown. Here, we investigated the expression of ADAR1 in Chinese pediatric acute leukemias by real-time PCR and Western blot. The results showed that significant high expression of p110 was detected in leukemias, especially in B-ALL, whereas a slight increase of p150 could be observed. Furthermore, the decrease of p110 expression was observed in B-ALL patients achieving complete remission. Moreover, among prognostic risk groups in ALL, the highest expressions of p110 and p150 were detected in standard-risk group, whereas their lowest expressions were in high-risk group. This observation was further confirmed in comparisons between good and poor prognostic groups based on prognostic related clinical features. These results demonstrated that ADAR1 isoforms showed different expression patterns, suggesting that they might play different roles in pediatric leukemias. Our results will help us for the better understanding of RNA editing, exploring the potential target for the treatment, and making prognostic evaluation in childhood leukemias.

A novel image decomposing algorithm is proposed in this paper, it can separate images into texture and cartoon parts under the complicated background. The main idea is the use of two appropriate dictionaries, one for the representation of textures, and the other for the cartoon parts assumed to be piecewise-smooth. The cartoon parts in the image can be sparsely represented by the local Ridgelet and the local Discrete Cosine transform is appropriate representation for texture parts. Furthermore, the use of Basic-Pursuit and Total-Variation regularization methods leads to the desired separation, along with noise removal as a by-product. The experiment results show that the image decomposition by the method is according with the human visual system.

To explore the value of the technique of multiplex fluorescence in sit hybridization (M-FISH) combined with interphase fluorescence in situ hybridization (FISH) in the identification of the chromosomal aberrations in multiple myeloma (MM) and to investigate the frequency of 13q14 deletion, IgH translocations and 17p13 deletion.Seven MM patients with complex chromosomal abnormalities (CCAs) were analyzed by combining the technique of conventional cytogenetics (CC) with M-FISH and FISH.M-FISH identified the aberrations which were undetected by CC, including twelve kinds of numeral aberrations and twenty-nine kinds of structural aberrations, In addition, abnormalities of chromosome 1, chromosomes 13 deletion and IgH translocations were the most frequent aberrations. Using the LSI D13S319 probe specific for 13q14, we observed a deletion of 13q14 in 6 MM patients; using the LSI p53 probe specific for 17p13, we observed p53 deletion in 4 MM patients; using the LSI IGHC/IGHV probe specific for 14q32, we observed a translocation involving 14q32 in 5 MM patients (43.5%), two translocations in two cases (case 6 and 7).M-FISH combined with FISH could refine the cytogenetics of MM patients and detect the missed abnormalities or correct the misidentified abnormalities analyzed by CC. It provides an ideal method for the research of chromosomal aberrations in MM.

To explore the molecular cytogenetic abnormalities in multiple myeloma (MM).Bone marrow plasma cells from 23 previously untreated MM patients were purified by CD138 McAb magnetic cell sorting system, and a panel of probes for interphase fluorescence in situ hybridization were used to detect the 13q14 deletion, p53 deletion and IgH gene translocation in the sorted MM cells.Among 23 MM patients, 13q14 deletion was observed in 10 (43.5%) cases, with the positive rate of 13q14 deleted cells ranged from 79% to 96%; 14q32 translocation was observed in 11 (47.8%) cases; 13q14 deletion and 14q32 translocation were simultaneously observed in 7 (30.4%) cases; and p53 deletion was observed in none of the 23 cases.The frequency of 13q14 deletion and IgH gene translocation in multiple myeloma are high; and the relationship between 13q14 deletion, IgH gene translocation and prognosis is worth further investigating.

OBJECTIVE: Recent reports have shown that C-X-C chemokine receptor 4 (CXCR4) is expressed in ovarian cancer and plays an important role in metastasis. However, the prognostic value of CXCR4 in ovarian cancer remains controversial and has not been emphasized. The aim of this study is to evaluate the prognostic significance of CXCR4 in ovarian cancer by performing a meta-analysis. METHODS: We systematically searched for studies evaluating the relationship between CXCR4 expression and the outcome of ovarian cancer patients. Only articles in which CXCR4 expression was detected by immunohistochemical staining were included. Hazard ratios (HRs) and relative risk (RR) with 95% confidence intervals (CIs) were pooled as effect size (ES) across studies for overall survival (OS) and progression-free survival (PFS). RESULTS: A total of 729 patients from 7 studies (6 articles) were included in this meta-analysis. Our results showed that high CXCR4 expression was significantly associated with poor prognosis in terms of OS (ES, 2.81; 95% CI, 1.16-6.80; p = 0.022) and PFS (ES, 8.48; 95% CI, 2.13-33.70; p = 0.002) in ovarian cancer patients. The association between high CXCR4 expression and poor ovarian cancer prognosis in OS was also statistically significant in subgroups of Asian and III-IV patients constituting 70%. CONCLUSIONS: The present meta-analysis indicated that high CXCR4 expression was associated with poor prognosis in ovarian cancer. More studies, especially larger scale and well-matched researches, are warranted to clarify the prognostic effect of CXCR4 on the outcome of ovarian cancer.

By utilizing generalized linear quantum transformation theory, the evolution operator, normal and anti-normal Wigner characteristic functions, P- and Q-representations of a multi-mode coupled quadratic Boson system are presented. The squeezing properties of a time-dependent double-mode coupled quadratic Bose system are investigated as a specific example.