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Feifei Li,1,2,* Zihou Li,2,3,* Xiaodong Jin,1 Yan Liu,1 Pengcheng Zhang,1,2 Ping Li,1 Zheyu Shen,3 Aiguo Wu,3 Weiqiang Chen,1 Qiang Li1 1Institute of Modern Physics, Chinese Academy of Sciences, Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Key Laboratory of Basic Research on Heavy Ion Radiation Application in Medicine, Gansu Province, Lanzhou 730000, China; 2University of Chinese Academy of Sciences, Beijing 100049, China; 3Key Laboratory of Magnetic Materials and Devices, Chinese Academy of Sciences, Division of Functional Materials and Nano Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China *These authors contributed equally to this work Background: Gadolinium-based nanoparticles (GdNPs) have been used as theranostic sensitizers in clinical radiotherapy studies; however, the biomechanisms underlying the radiosensitizing effects of GdNPs have yet to be determined. In this study, ultra-small gadolinium oxide nanocrystals (GONs) were employed to investigate their radiosensitizing effects and biological mechanisms in non-small-cell lung cancer (NSCLC) cells under X-ray irradiation.Method and materials: GONs were synthesized using polyol method. Hydroxyl radical production, oxidative stress, and clonogenic survival after X-ray irradiation were used to evaluate the radiosensitizing effects of GONs. DNA double-strand breakage, cell cycle phase, and apoptosis and autophagy incidences were investigated in vitro to determine the radiosensitizing biomechanism of GONs under X-ray irradiation.Results: GONs induced hydroxyl radical production and oxidative stress in a dose- and concentration-dependent manner in NSCLC cells after X-ray irradiation. The sensitizer enhancement ratios of GONs ranged between 19.3% and 26.3% for the NSCLC cells under investigation with a 10% survival rate compared with that of the cells treated with irradiation alone. Addition of 3-methyladenine to the cell medium decreased the incidence rate of autophagy and increased cell survival, supporting the idea that the GONs promoted cytostatic autophagy in NSCLC cells under X-ray irradiation.Conclusion: This study examined the biological mechanisms underlying the radiosensitizing effects of GONs on NSCLC cells and presented the first evidence for the radiosensitizing effects of GONs via activation of cytostatic autophagy pathway following X-ray irradiation. Keywords: gadolinium oxide nanocrystal, radiosensitization, cytostatic autophagy, apoptosis, oxidative stress

Abstract Background Child maltreatment can cause significant physical and psychological problems. The present study aimed to investigate the prevalence and determinants of child maltreatment in Guangzhou, China, where such issues are often considered a taboo subject. Methods A school-based survey was conducted in southern China in 2005. 24 high schools were selected using stratified random sampling strategy based on their districts and bandings. The self-administered validated Chinese version of parent-child Conflict Tactics Scale (CTSPC) was used as the main assessment tool to measure the abusive experiences encountered by students in the previous six months. Results The response rate of this survey was 99.7%. Among the 6592 responding students, the mean age was 14.68. Prevalence of parental psychological aggression, corporal punishment, severe and very serve physical maltreatment in the past 6 months were 78.3%, 23.2%, 15.1% and 2.8% respectively. The prevalence of sexual abuse is 0.6%. The most commonly cited reasons for maltreatment included 'disobedience to parents', 'poor academic performance', and 'quarrelling between parents'. Age, parental education, places of origins and types of housing were found to be associated with physical maltreatments whereas gender and fathers' education level were associated with sexual abuse. Conclusion Though largely unspoken, child maltreatment is a common problem in China. Identification of significant determinants in this study can provide valuable information for teachers and health professionals so as to pay special attention to those at-risk children.

The axisymmetric bending of a functionally graded circular plate, which is subjected to a concentrated transverse force at the center, is investigated based on a generalization of England’s method. The complex variable function method adopted in this paper involves four analytic functions of the complex variable, in which the unknown constants can be determined from cylindrical boundary conditions, similar to that in classical plate theory. The axisymmetric bending problem of a functionally graded circular plate concentrically loaded at the center can be converted into a bending problem of a functionally graded annular plate subject to shear forces uniformly distributed over the inner boundary. The elasticity solutions of a transversely isotropic and functionally graded circular plate subject to a concentrated force at the center are then derived, from which elasticity solutions for a transversely isotropic (or isotropic) and homogeneous circular plate can be obtained from the analysis as a special case. Finally, numerical examples are presented to compare the proposed analytical solutions with those of a finite-element method. The results show that the proposed elasticity solutions are very simple and usable. [ABSTRACT FROM PUBLISHER]

Recent researches have shown that the surface energy of some real elastic solids is unlikely to be positive semi-definite. Motivated by this, the present work studies counter-examples for uniqueness of the solution of surface elasticity theory in simple three-dimensional spherically symmetric and two-dimensional axi-symmetrical deformations. Simple sufficient conditions are derived for non-uniqueness of the solution in terms of bulk elastic modulus, surface elastic modulus and geometrical parameters of the elastic body. Unlike the non-uniqueness conditions for classical linear elasticity, which are given in terms of elastic constants alone, the geometrical dimensions of the elastic body play a key role in the non-uniqueness of the solution of surface elasticity theory. Roughly speaking, the solution of surface elasticity models can be non-unique if the smallest characteristic dimension of the body (such as thickness of a thin body, or diameter of a small body or a small hole in an elastic body) is below a certain critical value so that the magnitude of negative surface energy can compete with the positive bulk strain energy of the elastic body. For example, using the available data for the negative surface modulus suggested in the literature, our results predict that the solution could be non-unique for softer materials (such as rubbers) when the smallest characteristic dimension of the elastic body is below typically 1 µm. This result could predict self-buckling of softer elastic thin films in the presence of significant surface stresses. [ABSTRACT FROM PUBLISHER]

Background. The relationship between Epstein-Barr virus (EBV) and breast cancer (BC) is controversial. Interleukin-10 (IL-10) and interferon-[gamma] (IFN-[gamma]) are believed to play a critical role in the host's responses to EBV infection, and their genetic variations may modify the association of EBV with BC risk. Methods. We examined serum levels of EBV viral capsid antigen (VCA) immunoglobulin A (IgA) and nuclear antigen-1 (EBNA-1) IgA along with the polymorphisms of IL-10 rs1800871 and IFN-[gamma] rs2069705 in 354 incident BC cases and 504 age-matched controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using multivariate logistic regression. Results. VCA IgA and EBNA-1 IgA levels were positively associated with BC risk. IL-10 rs1800871 (TC/CC) was associated with a reduced BC risk (OR, 0.74 [95% CI, 0.55-1.00]) but had no interaction with EBV infection on BC risk. IFN-[gamma] rs2069705 was not directly associated with BC risk but interacted with EBNA-1 IgA on BC risk. Among women with the CC genotype, EBNA-1 IgA seropositivity significantly increased the risk of BC compared to EBNA-1 IgA seronegativity (OR, 5.14 [95% CI, 1.76-14.98]). Conclusions. These results suggest that EBV may contribute to the risk of BC and that this contribution may be modified by genetic variations in IFN-[gamma]. [ABSTRACT FROM AUTHOR]

An analytical model of a cracked functionally graded beam with attached Lead Zirconate Titanate (PZT) actuator/sensors is proposed in the paper for structural health monitoring. In this model, the dynamic behavior of the piezoelectric patches is considered and a viscoelastic law is adopted to describe the bonding imperfection between the piezoelectric patches and the beam. A piecewisely homogeneous beam model is then employed to approximate the original inhomogeneous beam based on the Timoshenko beam theory. The crack in the beam is treated as a massless rotational spring. In order to develop the recursive formulations to reduce the dimension of the final equations in the method of reverberation-ray matrix (MRRM), new local scattering relations are established for this smart beam using a matrix reduction technique. An analytical expression of the electromechanical impedance (EMI) is derived based on the improved MRRM via the recursive formulations. Comparison with existent experimental results and those predicted by other methods, such as the conventional MRRM, the transfer matrix method (TMM), and the finite element method (FEM), is made to validate the proposed analysis. Furthermore, the effects of various parameters including the crack depth on the EMI signatures are highlighted. [ABSTRACT FROM PUBLISHER]

An elastic continuous model is presented for the inclined cable with damage which is described as reduction of the axial stiffness. The damage effect on the static configuration of the cable under self-weight is investigated through a numerical solution. Hamilton’s principle is then employed to derive the governing equations for the in-plane dynamic motion of the cable-stayed beam with cable damage. The linear eigenmodes are obtained via the method of reverberation-ray matrix after a standard condensation procedure. A single-degree-of-freedom nonlinear model is obtained by the single-mode discretization. The homotopy analysis method is then successfully applied to get the frequency-amplitude relationship, which enables the influence of cable damage on the nonlinear dynamic behavior of the system to be characterized. [ABSTRACT FROM PUBLISHER]

While many risk factors for child physical abuse are known, little research exists examining these in multilevel contexts including both individual and environmental influences. The authors examined the roles of individual-, family- and community-level factors such as socioeconomic status (SES) in determining the likelihood of child physical abuse in Guangzhou, China. Twenty-four schools were recruited by stratified random sampling, with 6628 junior high-school students aged 13-16 years participating. Parental child physical abuse experience, together with family and community levels of SES among students were measured and their relationships were investigated by applying univariable, multivariable and multilevel logistic regression models. Univariable, multivariable and multilevel logistic regression models were applied. Six-month prevalence of minor, severe and very severe assaults were 23.2%, 15.1% and 2.8%, respectively. A U-shaped association between family SES and likelihood of severe assaults was identified. In the multilevel model, indicators of low family SES, mother's higher occupational and educational status remained significantly independent predictors of physical abuse. Internal migration status was associated with higher risk as was younger age. The authors suggest that previous categories of risk factors for physical abuse may be too simplistic, and that further research on social and environmental influences may usefully inform intervention programs. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To assess the prevalence of anxiety and depressive symptoms among patients with somatic diseases in urban China. METHOD: A hospital-based cross-sectional study was carried out in four major cities of China from June to August in 2004. There were 2111 eligible subjects with Stroke, Parkinson's Disease, Epilepsy, Irritable Bowel Syndrome, Functional Dyspepsia, and Menopausal Syndrome, and 317 Post-natal women were recruited from general hospitals. Self-completed hospital anxiety and depression scale (HAD) questionnaire was used for screening anxiety and/or depressive symptoms. Subjects with a HAD score of > = 9 were further assessed with Hamilton anxiety scale (HAMA) and Hamilton depression scale (HAMD) by certified psychologists or psychiatrists. RESULTS: The prevalence of 'screened' depressive and anxiety symptoms using HAD were 11-19% and 11-22% respectively in patients with above somatic diseases and post-natal women. Assessed by HAMA/HAMD scale, the prevalence of 'definite' depressive symptoms was 30%-59% in subjects with 'screened' depressive symptoms, and 44%-84% in subjects with 'screened' anxiety symptoms. About half of the subjects had co-morbidity depressive and anxiety symptoms. Less than one-fourth of these subjects had ever been diagnosed as depressive/anxiety disorders and been treated prior to the investigation. CONCLUSION: There is a high prevalence and low diagnosis and treatment rate of depressive and anxiety symptoms in patients with these somatic diseases in China. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The objective of this study was to observe the variation of energy intake and energy expenditure in the obese Chinese children. METHODS: Basic metabolic rate was measured by using open-circuit indirect calorimetry in 54 obese children and 60 non-obese children aged 10-12 years in a full- time boarding school in Guangzhou suburb, China. Total energy expenditure was estimated by using a factorial method. Dietary intake was surveyed by the weighed inventory method. Physical activity was determined using a 2-day activity diary. RESULTS: Univariate analysis showed that basic metabolic rate was significantly higher (p<0.05) in obese children than in non-obese ones, but the significant difference disappeared after controlling for fat free mass and fat mass. Energy intake and total energy expenditure were significantly higher (p<0.05) in obese than in non-obese children. Obese children spent more time in sleeping and light physical activity, but less time in moderate physical activity and vigorous physical activity than non-obese children (p<0.05). CONCLUSIONS: Compared to non-obese children, both energy intake and expenditure were higher in obese Chinese children. It appears that an area for preventive strategies may be to encourage increased physical activity expenditure in this age group. [ABSTRACT FROM AUTHOR]