Interface analysis of 7B52 Al alloy laminated composite fabricated by hot-roll bonding

The bonding interface of 7B52 Al alloy laminated composite （ALC） fabricated by hot rolling was investigated using optical microscopy （OM）, transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, ultrasonic flaw detection （UFD）, and bonding strength tests. The results show that metallurgical bonding is achieved at the interface after composite rolling. The TEM analysis and tensile tests indicate that the 7B52 ALC plate combines high strength of the hard individual layer and good toughness of the soft individual layer. However, UFD technology and SEM analysis prove that the defects （thick oxide films, acid washed residues, air, oil and coarse particles） existing in the bonding interface are harmful to the bonding strength. To sum up, the composite roiling process is suitable for 7B52 ALC plate, and the content and size of the defects should be controlled strictly. Advanced surface treatment of each individual layer would be beneficial to further improve the bonding quality.

Pancreatic neuroendocrine neoplasms: Magnetic resonance imaging features according to grade and stage

AIMTo describe magnetic resonance (MR) imaging features of pancreatic neuroendocrine neoplasms (PanNENs) according to their grade and tumor-nodes-metastases stage by comparing them to histopathology and to determine the accuracy of MR imaging features in predicting their biological behavior.METHODSThis study was approved by our institutional review board; requirement for informed patient consent was waived due to the retrospective nature of the study. Preoperative MR examinations of 55 PanNEN patients (29 men, 26 women; mean age of 57.6 years, range 21-83 years) performed between June 2013 and December 2015 were reviewed. Qualitative and quantitative features were compared between tumor grades and stages determined by histopathological analysis.RESULTSIll defined margins were more common in G2-3 and stage III-IV PanNENs than in G1 and low-stage tumors (P < 0.001); this feature had high specificity in the identification of G2-3 and stage III-IV tumors (90.3% and 96%, 95%CI: 73.1-97.5 and 77.7-99.8). The mean apparent diffusion coefficient value was significantly lower in G2-3 and stage III-IV lesions compared to well differentiated and low-stage tumors (1.09 × 10-3 mm2/s vs 1.45 × 10-3 mm2/s and 1.10 × 10-3 mm2/s vs 1.53 × 10-3 mm2/s, P = 0.003 and 0.001). Receiving operator characteristic analysis determined optimal cut-offs of 1.21 and 1.28 × 10-3 mm2/s for the identification of G2-3 and stage III-IV tumors, with sensitivity and specificity values of 70.8/80.7% and 64.5/64% (95%CI: 48.7-86.6/60-92.7 and 45.4-80.2/42.6-81.3).CONCLUSIONMR features of PanNENs vary according to their grade of differentiation and their stage at diagnosis and could predict the biological behavior of these tumors.

Self-organized Critical Model Based on Complex Brain Networks with Hierarchical Organization

The dynamical behavior in the cortical brain network of macaque is studied by modelling each cortical areawith a subnetwork of interacting excitable neurons.We find that the avalanche of our model on different levels exhibitspower-law.Furthermore the power-law exponent of the distribution and the average avalanche size are affected by thetopology of the network.

Prognostic value of chemotherapy-induced leukopenia in small-cell lung cancer

Objective: Chemotherapy is the standard treatment for small-cell lung cancer (SCLC), and leukopenia is a common side effect. This study assesses whether chemotherapy-induced leukopenia is a predictor of efficacy and whether it is associated with the survival of SCLC patients. Methods: A retrospective analysis was conducted on data from 445 patients with SCLC who received standard chemotherapy for 4 to 10 cycles. The World Health Organization grading system classifies leukopenia during chemotherapy as follows: absent (grade 0), mild (grades 1 and 2), or severe (grades 3 and 4). The primary endpoint is overall survival (OS). Results: The association between chemotherapy-induced leukopenia and OS was assessed. According to a multivariate Cox model with time-varying covariates, the hazard ratio of death was significantly lower among patients with mild leukopenia than among patients with severe leukopenia at 0.687 (0.506 to 0.943) and 1.414 (1.147 to 1.744), respectively. The median survival was 13 months (95% CI: 11 to 15 months) for patients who did not experience leukopenia, 17 months (95% CI: 14 to 18 months) for those with mild leukopenia, and 14 months (95% CI: 13 to 16 months) for those with severe leukopenia (absent vs. mild vs. severe leukopenia, P=0.047). Conclusion: Leukopenia during chemotherapy is associated with the survival of SCLC patients. Mild leukopenia is strongly associated with longer survival time.

World Cities and International Organizations: Political Global-city Status of Chinese Cities

In this study, the authors use a political perspective to explore the relative global status of cities in China. Two questions are addressed. Firstly, by using international organizations as the subjects and quantitative analysis of the spatial distribution of their offices, the overall position of Chinese cities in the global distribution of international organizations is estimated. The results show that 22 Chi- nese cities are involved in international political affairs. Beijing, Shanghai and Guangzhou dominate these activities and have high po- litical global-city status. Secondly, through qualitative analysis of Guangzhou City, the authors explore how its status as a center for intemational organizations has been shaped in recent years. The locational decision-making process is analyzed and the factors are demonstrated at both national and city scales. The definition of international organizations as used in this study refers not only to those supranational bodies that have the ability to manage relations across states （such as the European Union）, but also those in- ter-governmental organizations （IGOs）, international non-governmental organizations （INGOs） and diplomatic representatives and delegations that today also manage and regulate relations between and among states.

Observation of Intensity-Modulated Radiotherapy with Different Fractionated Doses Used in 58 Cases with Astrocytoma

OBJECTIVE To analyze the therapeutic effects and side effects of intensity-modulated radiotherapy （IMRT） with different fractionated doses in treating astrocytoma.METHODS During a period from October 2001 to December 2006, 58 patients with astrocytoma were treated using IMRT. Based on the World Health Organization （WHO） classification, 32 of the 58 cases were grade-Ⅱ, 20 grade-Ⅲ and 6 grade-IV （glioblastoma multiforme, GBM）. Thirty-two of the 58 patients （3 with grade IV, 11 with grade Ⅲ, and the other 18 with grade II who were over 40 years） were treated with hyperfractionated IMRT （Hyper Fr IMRT）, and the other 26 patients were treated with standard fractionated IMRT （St Fr IMRT）.RESULTS The 1-, 3- and 5-year overall survival （OS） rates were respectively 86%, 52%, and 45%, and the 1-, 3- and 5-year progression-free survival （PFS） rates were respectively 77%, 38%, and 25%. Using an analytical hierarchy process it was shown that concerning the patients with grade II astrocytoma classified based on WHO grading, the therapeutic effect was much better in the group of Hyper Fr IMRT than in the St Fr IMRT group. There was no statistical significance of the differences in the OS and PFS rates between the 2 groups （P = 0.049 and P = 0.006）. The OS and PFS rates of the patients with grade-III astrocytoma were both higher in the group with Hyper Fr IMRT than in the St Fr IMRT group. However, there was no statistical significance of the differences between the 2 groups. Advanced RTOG grade-Ⅲ（radiation therapy oncology group, RTOG） neurotoxicity occurred only in 1 of the cases.CONCLUSION Compared with the St Fr IMRT, the Hyper Fr IMRT may help to prolong the survival of patients with astrocytoma.

An Assessment of Ingestion Dose due to the Intake of ^210Po and ^210Pb through Drinking Water of Eloor, Ernakulam District, Kerala, India

The present study aims at measuring the activity concentrations of ^210Po and ^210Pb in the potable water of Eloor, a major industrial belt in the Ernakulam district of Kerala, India with an aim of evaluating resultant ingestion dose to critical population. The industrial units located in Eloor discharge their treated effluents into the river Periyar and the surrounding environs. The two major industries of interest with respect to NORMs are the fertilizer plant, processing rock phosphate and the monazite processing plant, which had been in operation for the last 50 years. For sampling, Eloor region was divided into four zones and a total of 55 water samples from different locations were collected and analysed as per standard analytical procedure manual of BARC. The ^210Po concentration ranged between 0.3 to 4.7 mBq.L^-1 and ^210Pb ranged from 0.6 to 4.3 mBq.L^-1. All values are well below the limit of 0.1 Bq.Ll recommended by World Health Organization. Statistical analysis shows a good co-relation between ^210Po and ^210Pb in the water samples analyzed and the mean activity concentration is found to be relatively high in the western region of Eloor compared to other regions. The annual effective dose equivalent to man from ^210Po and ^210Pb through drinking water intake were estimated and found to be 1.13 μSv.y^-1 and 0.99 μSv.y^-1 respectively, which is well below the reference level of committed effective dose （100 μSv.y^-1） recommended by WHO.

合作社与集体经济组织两者关系亟须厘清——以我国《宪法》的完善为中心

合作社与集体经济组织是两类性质互不相同的经济组织。两者不容混淆,也不易混淆。我国现行《宪法》在规范两者关系方面有待继续完善,未来修正后的《宪法》应在厘清合作社与集体经济组织两者关系的基础上,针对合作社,不仅作出单独规定,而且作出保护性规定。如此,有利于促进农民合作社健康快速发展,进而推动农村经济社会发展。

Self-Organized Criticality Analysis of Earthquake Model Based on Heterogeneous Networks

The original Olami-Feder-Christensen （OFC） model, which displays a robust power-law behavior, is a quasistatic two-dimensional version of the Burridge-Knopoff spring-block model of earthquakes. In this paper, we introduce a modified OFC model based on heterogeneous network, improving the redistribution rule of the original model. It can be seen as a generalization of the originM OFC model We numerically investigate the influence of the parameters θandβ, which respectively control the intensity of the evolutive mechanism of the topological growth and the inner selection dynamics in our networks, and find that there are two distinct phases in the parameter space （θ,β）. Meanwhile, we study the influence of the control parameter a either. Increasing a, the earthquake behavior of the model transfers from local to global.

Quality Assessment of Drinking Water in Tanta City, Egypt

The physico-chemical and biological （algal and bacterial） quality of tap water in Tanta City were elucidated. Samples were collected during December 2011, covering all the water plants and the areal extension of the pipe line network in Tanta. Total dissolved solids content classifies water origin into surface water, shallow and deep groundwater. Fe, Mn and hardness in some samples of groundwater origin are obviously exceeding the WHO （World Health Organization） limit. Mostly, green algae are found （31 species）, followed by diatoms （19 species）, then blue-green algae （13 species）. CCA （Canonical Corresponding Analysis） indicates that green algae are strongly correlated with pH, NH4, alkalinity, Mn and Si; diatoms with EC （electric conductivity）, turbidity, Zn and Si and blue green algae with EC and alkalinity. 50% of samples of surface origin, 80% of samples of both deep and shallow groundwater origins crossed WHO and Egyptian guideline in their content of mean TCC （Total Coliform Count）. CCA estimates strong correlations of TCC with temperature, NH4 and PO4; E. coli with EC; heterotrophic bacteria with turbidity and NO3; Salmonella sp. with Si and SO4 and Pseudomonas aeruginosa with Mn. Finally, the water plants treatment may be not effective and pipes serve as a reservoir for pathogenic microorganisms.

Micro-CT evaluation and histological analysis of screwbone interface of expansive pedicle screw in osteoporotic sheep

Objective： To investigate the properties of screwbone interface of expansive pedicle screw （EPS） in osteoporotic sheep by micro-CT and histological observation. Methods： Six female sheep with bilateral ovariectomyinduced osteoporosis were employed in this experiment. After EPS insertion in each femoral condyle, the sheep were randomly divided into two groups： 3 sheep were bred for 3 months （Group A）, while the other 3 were bred for 6 months （Group B）. After the animals being killed, the femoral condyles with EPS were obtained, which were three-dimensionally-imaged and reconstructed by micro-CT. Histological evalu-ation was made thereafter. Results： The trabecular microstructure was denser at the screw-bone interface than in the distant parts in expan-sive section, especially within the spiral marking. In the non- expansive section, however, there was no significant differ-ence between the interface and the distant parts. The regions of interest （ROI） adjacent to EPS were reconstructed and analyzed by micro-CT with the same thresholds. The three-dimensional （3-D） parameters, including tissue min- eral density （TMD）, bone volume fraction （BVF, BV/TV）, bone surface/bone volume （BS/BV） ratio, trabecular thickness （Tb.Th）, and trabecular separation （Tb.Sp）, were sig- nificantly better in expansive sections than non-expan-sive sections （P 〈 0.05）. Histologically, newly-formed bony trabeculae crawled along the expansive fissures and into the center of EPS. The newly-formed bones, as well as the bones at the bone-screw interface, closely contacted with the EPS and constructed four compartments. Conclusions： The findings of the current study, based on micro-CT and histological evaluation, suggest that EPS can significantly provide stabilization in osteoporotic cancellous bones.

Tailored microstructures and strengthening mechanisms in an additively manufactured dualphase high-entropy alloy via selective laser melting

Dual-phase high-entropy alloys(DP-HEAs)with excellent strength-ductility combinations have attracted scientific interests.In the present study,the microstructures of AlCrCuFeNi3.0DP-HEA fabricated via selective laser melting(SLM)are rationally adjusted and controlled.The mechanisms engendering the hierarchical microstructures are revealed.It is found that the AlCrCuFeNi3.0fabricated by SLM at the scanning speed of 400 mm s-1falls into the eutectic coupled zone,and increasing the scanning speed will make this composition deviate away from the eutectic coupled zone due to the increased cooling rate.The enrichment of Cr and Fe solutes with large growth restriction values ahead of the solid/liquid interface can develop a constitutional supercooling zone,thus facilitating the heterogeneous nucleation and nearequiaxed grain formation.The synergy of the near-eutectic DP nano-structures and near-equiaxed grains instead of columnar ones effectively suppresses cracking for the as-built DP-HEA.During the tensile deformation,the intergranular back stress hardening similar to the grain-boundary strengthening is discovered.Meanwhile,the near-eutectic microstructures comprised of soft face-centered cubic and hard ordered bodycentered cubic(B2)DP nano-structures lead to plastic strain incompatibility within grains,thus producing the intragranular back stress.The Cr-rich nano-precipitates inside the B2 phase are found to be sheared by dislocation gliding and can complement the back stress.Additionally,multiple strengthening mechanisms are physically evaluated,and the back stress strengthening contributes obviously to the high performances of the as-built DP-HEA.

Effect of Correlations on the Exponents for the Power-Law Distributions in Self-Organized Criticality

The origin of power-law distributions in self-organized criticality is investigated by treating the variation of the number of active sites in the system as a stochastic process. An avalanche is mapped to a first-return random-walk process in a one-dimensional lattice. In order to understand the reason of variant exponents for the power-law distributions in different self-organized critical systems, we introduce the correlations among evolution steps. Power-law distributions of the lifetime and spatial size are found when the random walk is unbiased with equal probability to move in opposite directions. It is found that the longer the correlation length, the smaller values of the exponents for the power-law distributions.