State-of-the-art review of automated structural design optimization

The 20th working conference of the IFIP Working Group 7.5 on Reliability and Optimization of Structural Systems (IFIP 2022) will be held at Kyoto University, Kyoto, Japan, September 19-20, 2022.Automated and intelligent structural design optimization has been a heated research topic in structural engineering community. The automated structural design may learn from existing design drawings and finite element models of previous design, infuse design experts' knowledge with design standards and codes, and notably reduce the time and difficulty of structural design compared to conventional approach. This study provides a review of current automated structural design optimization approaches, which may be categorized as the approaches based on finite element model and the deep-learning approach based on human design dataset. For the design optimization based on finite element model, the gradient-based algorithm and gradient-free algorithm are illustrated and compared. The selection of objective function and constraint functions for structural design optimization are summarized. The parallel computing method developed based on high-performance computing resources are also summarized. In addition, the deep learning approaches, which directly generate preliminary structural design drawings based son architectural drawings and datasets of human design results are also summarized. Major architectures in this research field are discussed, including generative adversarial networks (GAN), diffusion models and Variational Auto-Encoder (VAE). The combination between deep learning approach and conventional finite-element model-based approach are also discussed and the future development trends and potential challenges are discussed

Impacts of undetected and inadequately treated hypertension on incident stroke in China

OBJECTIVES: China carries the greatest burden of stroke given its largest volume of people with hypertension. This study assessed the impacts of suboptimal controls of hypertension on incident stroke and projected the number of patients with stroke saved after the control of blood pressure improved in population. SETTING: Anhui, China. PARTICIPANTS: We examined data from the Anhui cohort of 2001-2011, consisting of 3336 participants aged ≥60 years who were randomly recruited from the urban and rural Anhui. 2852 participants (89.2%) had hypertensive status measured and no stroke at baseline, and were followed up until 2011 in three surveys using a standard method of interview. RESULTS: At baseline, 1646 participants (57.7%) were identified to have hypertension, among whom 912 (55.4%) were previously undetected, 115 (7.0%) detected but not treated, 452 (27.5%) treated but not controlled and only 127 (7.7%) controlled. During the 10-year follow-up, 211 incident stroke cases (12.8/1000 person-years) occurred. Compared with normotensive individuals at baseline, multivariate adjusted HR for having stroke increased in those with undetected hypertension by 1.63 (95%CI 1.15 to 2.32), untreated by 2.21 (1.26-3.85) and uncontrolled hypertension by 3.34 (2.28-4.88), but did not differ from those with controlled hypertension (1.34; 0.60-2.99). Based on a two-fold increase in the detection and management of current levels of hypertension and algorithms on the current situation in China, approximately 250 000 incident stroke cases could be prevented annually. CONCLUSIONS: In China, hypertension is frequently undetected or inadequately treated. With appropriate management of hypertension, a substantial number of people could be saved form stroke

Bis(2-{2-[2-(benzyl­carbamo­yl)phen­oxy]acetamido}­eth­yl)ammonium nitrate ethanol disolvate

In the title compound, C36H40N5O6 +·NO3 −·2C2H5OH, the nitrate anion is disordered over the two orientations of equal occupancy while the solvent mol­ecule reveals large displacement parameters. The cation is formed by protonation of the N atom of a secondary amine in the middle of the flexible chain and the whole compound has crystallographically imposed C-2 symmetry with the crystallographic b axis. An O atom of the nitrate anion links the acidic H atoms of the cation via N—H⋯O hydrogen bonding. In addition, neighbouring cations are connected by inter­molecular N—H⋯O hydrogen bonds and π–π inter­actions between the benzamide groups of the cations [centroid–centroid distance = 4.000 (3) Å], forming a chain along [001]. The ethanol solvent mol­ecules are arranged on the side of the chain through O—H⋯O hydrogen bonds

Generation of Photonic Hooks under Point-Source Illumination from Patchy Microcylinders

Photonic hook (PH) is a new type of non-evanescent light beam with subwavelength curved structures. It has shown promising applications in super-resolution imaging and has the potential to be used in micromachining, optical trapping, etc. PHs are generally produced by illuminating mesoscale asymmetric particles with optical plane waves. In this work, we used the finite-difference time-domain (FDTD) method to investigate the PH phenomenon under point-source illumination. We found that the PHs can be effectively generated from point-source illuminated patchy particles. By changing the background refractive index, particle diameters and the position and coverage ratio of Ag patches, the characteristics of the PHs can be effectively tuned. Moreover, the structure of the intensity distribution of the light field generated from small and large particles can have an opposite bending direction due to the near-field light-matter interaction

Microglia exacerbate white matter injury via complement C3/C3aR pathway after hypoperfusion.

Microglial activation participates in white matter injury after cerebral hypoperfusion. However, the underlying mechanism is unclear. Here, we explore whether activated microglia aggravate white matter injury via complement C3-C3aR pathway after chronic cerebral hypoperfusion. Methods: Adult male Sprague-Dawley rats (n = 80) underwent bilateral common carotid artery occlusion for 7, 14, and 28 days. Cerebral vessel density and blood flow were examined by synchrotron radiation angiography and three-dimensional arterial spin labeling. Neurobehavioral assessments, CLARITY imaging, and immunohistochemistry were performed to evaluate activation of microglia and C3-C3aR pathway. Furthermore, C3aR knockout mice were used to establish the causal relationship of C3-C3aR signaling on microglia activation and white matter injury after hypoperfusion. Results: Cerebral vessel density and blood flow were reduced after hypoperfusion (p<0.05). Spatial learning and memory deficits and white matter injury were shown (p<0.05). These impairments were correlated with aberrant microglia activation and an increase in the number of reactive microglia adhering to and phagocytosed myelin in the hypoperfusion group (p<0.05), which were accompanied by the up-regulation of complement C3 and its receptors C3aR (p<0.05). Genetic deletion of C3ar1 significantly inhibited aberrant microglial activation and reversed white matter injury after hypoperfusion (p<0.05). Furthermore, the C3aR antagonist SB290157 decreased the number of microglia adhering to myelin (p<0.05), attenuated white matter injury and cognitive deficits in chronic hypoperfusion rats (p<0.05). Conclusions: Our results demonstrated that aberrant activated microglia aggravate white matter injury via C3-C3aR pathway during chronic hypoperfusion. These findings indicate C3aR plays a critical role in mediating neuroinflammation and white matter injury through aberrant microglia activation, which provides a novel therapeutic target for the small vessel disease and vascular dementia

Correlation-driven eightfold magnetic anisotropy in a two-dimensional oxide monolayer.

Engineering magnetic anisotropy in two-dimensional systems has enormous scientific and technological implications. The uniaxial anisotropy universally exhibited by two-dimensional magnets has only two stable spin directions, demanding 180° spin switching between states. We demonstrate a previously unobserved eightfold anisotropy in magnetic SrRuO3 monolayers by inducing a spin reorientation in (SrRuO3)1/(SrTiO3) N superlattices, in which the magnetic easy axis of Ru spins is transformed from uniaxial 〈001〉 direction (N &lt; 3) to eightfold 〈111〉 directions (N ≥ 3). This eightfold anisotropy enables 71° and 109° spin switching in SrRuO3 monolayers, analogous to 71° and 109° polarization switching in ferroelectric BiFeO3. First-principle calculations reveal that increasing the SrTiO3 layer thickness induces an emergent correlation-driven orbital ordering, tuning spin-orbit interactions and reorienting the SrRuO3 monolayer easy axis. Our work demonstrates that correlation effects can be exploited to substantially change spin-orbit interactions, stabilizing unprecedented properties in two-dimensional magnets and opening rich opportunities for low-power, multistate device applications

Prevalence of internet addiction and its association with stressful life events and psychological symptoms among adolescent internet users

Internet addiction (IA) among adolescents is a serious public health problem around the world. However, there have been few studies that examine the association between IA and stressful life events and psychological symptoms among Chinese adolescent internet users. We examined the association between IA and stressful life events and psychological symptoms among a random sample of school students who were internet users (N = 755) in Wuhan, China. Internet addiction, stressful life events, coping style and psychological symptoms were measured by self-rated scales. The prevalence rate of internet addiction was 6.0% among adolescent internet users. Logistic regression analyses indicated that stressors from interpersonal problem and school related problem and anxiety symptoms were significantly associated with IA after controlling for demographic characteristics. Analyses examining the coping style with the IA revealed that negative coping style may mediate the effects of stressful life events to increase the risk of IA. However, no significant interaction of stressful life events and psychological symptoms was found. These findings of the current study indicate a high prevalence of internet addiction among Chinese adolescent internet users and highlight the importance of stressors from interpersonal problem and school related problem as a risk factor for IA which mainly mediated through negative coping style.Published versio

Use of traditional and complementary medicine as self-care strategies in community health centers

In China, Community Health Centers (CHCs) are major providers of primary care services, but their potential in empowering patients’ self-management capacity has not been assessed. This study aims to describe self-care practice patterns amongst CHC attendees in urban China. In this cross-sectional quantitative study, 3360 CHC patients from 6 cities within the Pearl Delta Region were sampled using multistage cluster sampling. Thirty-seven per cent had used with over-the-counter Chinese herbal medicines (OTC CHMs) in the past year and majority of respondents found OTC CHMs effective. OTC CHMs were more popular amongst those who needed to pay out of pocket for CHC services. Less than 10% used vitamins and minerals, and those with a lower socioeconomic background have a higher propensity to consume. Although doubts on their usefulness are expressed, their use by the vulnerable population may reflect barriers to access to conventional health care, cultural affinity, or a defense against negative consequences of illnesses. About 25% performed physical exercise, but the prevalence is lower amongst women and older people. Taiji seems to be an alternative for these populations with promising effectiveness, but overall only 6% of CHC attendees participated. These results suggest that CHCs should start initiatives in fostering appropriate use of OTC CHM, vitamins, and minerals. Engaging community pharmacists in guiding safe and effective use of OTC CHM amongst the uninsured is essential given their low accessibility to CHC services. Prescription of Taiji instead of physical exercises to women and older people could be more culturally appropriate, and the possibility of including this as part of the CHC services worth further exploration

Development of a Novel Electromagnetic Rewarming Technology for the Cryopreservation of Stem Cells with Large Volume

Applications of stem cells have been playing significant roles in scientific and clinical settings in the last few decades. The foundation of these approaches is successful cryopreservation of stem cells for future use. However, so far we can only cryopreserve stem cell suspension of small volumes in the order of 1 mL mostly due to the lack of an effective rewarming technique. Rapid and uniform rewarming has been approved to be beneficial, and sometimes, indispensable for the survival of cryopreserved stem cells, inhibiting ice recrystallization or devitrification. Unfortunately, the conventional water bath thawing method failed in providing the rapid and uniform rewarming. The conversion of electromagnetic (EM) energy into heat provides a possible solution to this problem. This chapter will focus on (1) analysis of the combined EM and heat transfer phenomenon in the rewarming of a biospecimen, (2) numerical investigation of the rewarming system, (3) practical setup of an EM resonance system, and (4) test of heating performance with large volume of cells