Background. During the outbreak of coronavirus disease 2019 (COVID-19), people are under the dual pressure of interpersonal isolation and concerns about infection. An evaluation of people’s psychological status and risk factors is needed to conduct target interventions. Methods. This was a nationwide, multicenter, cross-sectional study using quota and snowball sampling methods during the COVID-19 epidemic in China. Participants’ characteristics and experiences were obtained by an online questionnaire and telephone review. Psychological distress and sleep problems were measured by the Generalized Anxiety Disorder-7, the Patient Health Questionnaire-9, and the Insomnia Severity Index. Results. A total of 23,500 participants were recruited, and 19,372 valid questionnaires were received from 11 centers. Overall, 11.0–13.3% of the participants had anxiety, depression, or insomnia symptoms, and 1.9–2.7% had severe symptoms. The prevalence of psychological and sleep problems has increased. Working as frontline medical staff (Odds Ratio OR = 3.406), living in Hubei Province (OR = 2.237), close contacts with COVID-19 (OR = 1.808), and age 35–49 years (OR = 1.310) were risk factors for anxiety symptoms; no outside activity for 2 weeks (OR = 2.167) and age 35–49 years (OR = 1.198) were risk factors for depression symptoms; and living in Hubei Province (OR = 2.376), no outside activity for 2 weeks (OR = 1.927), and age 35–49 years (OR = 1.262) were risk factors for insomnia symptoms. Only 1.9% of participants received counseling during the epidemic. Conclusions. Psychological and sleep problems increased during interpersonal isolation due to COVID-19. Current psychological interventions are far from sufficient.

Purpose To determine whether there are in vivo differences of γ-aminobutyric acid (GABA) levels in frontal and parietal regions of Alzheimer’s disease (AD) patients, compared with healthy controls using magnetic resonance spectroscopy (1H-MRS). Materials and Methods Fifteen AD patients and fifteen age- and gender-matched healthy controls underwent 1H-MRS of the frontal and parietal lobes using the “MEGA-Point Resolved Spectroscopy Sequence” (MEGA-PRESS) technique, and cognitive levels of subjects were evaluated using Mini-Mental State Examination (MMSE) tests. MRS data were processed using the Gannet program. Because the signal detected by MEGA-PRESS includes contributions from GABA, macromolecules and homocarnosine, it is labeled as “GABA+” rather than GABA. Differences of GABA+/Cr ratios between AD patients and controls were tested using covariance analysis, adjusting for gray matter fraction. The relationship between GABA+/Cr and MMSE scores was also analyzed. Results Significant lower GABA+/Cr ratios were found in the parietal region of AD patients compared with controls (P = 0.041). In AD patients, no significant correlations between GABA+/Cr and MMSE scores were found in either the frontal (r = −0.164; P = 0.558) or parietal regions (r = 0.025; P = 0.929). Conclusion Decreased GABA+/Cr levels were present in the parietal region of patients with AD in vivo, suggesting that abnormalities of the GABAergic system may be present in the pathogenesis of AD.

Introduction: Subcortical vascular mild cognitive impairment (svMCI) is the predemen-

Objective In this study, the authors analyzed the status of anxiety depression and insomnia symptoms and influential factors in the work resumption period of Coronavirus disease 2019 (COVID-19). Methods A multicenter cross-sectional survey was conducted from March 2, 2020 to March 8, 2020 in Shandong Province, China, using quota sampling combined with snowball sampling. The Generalized Anxiety Disorder-7 (GAD-7), the Patient Health Questionnaire-9 (PHQ-9), and the Insomnia Severity Index (ISI) were used to assess the anxiety, depression, and insomnia symptoms. The multivariate logistic regression analysis was used to explore the influential factors. Results A total of 4000 invitations were sent from three centers, 3237 valid questionnaires were received. Based on GAD-7, PHQ-9, and ISI scales, 19.5%–21.7% of the participants had anxiety, depression, or insomnia symptoms; 2.9%–5.6% had severe symptoms. Besides, 2.4%, 4.8%, and 4.5% of the participants had anxiety-depression, anxiety-insomnia, or depression-insomnia combined symptoms. The scores of anxiety and insomnia symptoms, along with scores of depression and insomnia symptoms were positively correlated in these samples. Aged 50–64 years and outside activities once in ≥30 days were risk factors of anxiety, depression, and insomnia symptoms in common. During the epidemic, 17.4% of the participants had received psychological interventions, and only 5.2% had received individual interventions. Conclusions The incidence of psychological distress increased during the outbreak of COVID-19 in the work resumption period than the normal period. Current psychological interventions were insufficient; target psychological interventions should be conducted in time.

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By using the reciprocal theorem of elasticity, the author obtained the appropriate stress boundary conditions for the Levy solution for plate bending accurate to all order for plates of general edge geometry and loading. Two special cases of k = 0 (axisymmetric deformation of a circular plate) and k P 2 (unsymmetric deformation of a circular plate) were discussed in detail in the paper.However, for the first case, the author indicated, ''However, they determine only the Fourier coefficient b 0 but not the rigid body transverse displacement component a 0 . Such a level of nonuniqueness is expected when all edge data are prescribed in terms of stresses.' ' (p. 4115, lines 20-22). To determine the Fourier coefficient a 0 , the second singular axisymmetric biharmonic function w 0 0 (r) = r 2 ln r in Eqs. (21) in Wan (2003) should be used. For this singular biharmonic function, the relevant displacement and stress components of the Levy solution are0020-7683/$ -see front matter Ó

The problem of deducing one-dimensional theory from two-dimensional theory for a homogeneous isotropic beam is investigated. Based on elasticity theory, the refined theory of rectangular beams is derived by using Papkovich-Neuber solution and Lur'e method without ad hoc assumptions. It is shown that the displacements and stresses of the beam can be represented by the angle of rotation and the deflection of the neutral surface. Based on the refined beam theory, the exact equations for the beam without transverse surface loadings are derived and consist of two governing differential equations: the fourth-order equation and the transcendental equation. The approximate equations for the beam under transverse loadings are derived directly from the refined beam theory and are almost the same as the governing equations of Timoshenko beam theory. In two examples, it is shown that the new theory provides better results than Levinson's beam theory when compared with those obtained from the linear theory of elasticity.The beam theory has been studied for many years. In the early eighteenth century, Bernoulli and Euler presented the classical beam theory, and Timoshenko [1] introduced the shear theory of beams, then Cowper [2] gave the shear coefficients. Since then, more and more work on the subject has been done by the following researchers, i.e., Levinson [3] , Bickford [4] , Tutek and Aganović [5] , Lewiński [6] , Fan and Widera [7] , Tullini and Savoia [8] .Cheng [9] gave a refined plate theory from Boussinesq-Galerkin elasticity solution and Lur'e method [10] without ad hoc assumptions. The refined plate theory consists of three parts: the biharmonic equation, the shear equation and the transcendental equation. Peo-