Search

Familiar strangers—individuals related through regular and repeated visual encounter occurring without verbal interaction—may reduce the risk of crime at places by increasing guardianship and internal motivation for norm compliance. This study examines the association between familiar stranger presence and incidents of theft and disorder at train stations using transit smart card and crime data for 22 stations across a six-month period. Familiar strangers are operationally defined as individual transit cards that are co-present within a 30-min temporal window on more than two occasions across a one-month period at a given train station. We apply logistic regression to estimate the likelihood of disorder and theft crimes within a 400-m radius of train stations controlling for station environmental features, co-located facilities and neighbourhood socio-demographic characteristics. Our results show that the impact of familiar strangers on crime (disorder and theft) at train stations is moderated by the neighbourhood socio-demographic context. This may suggest that macro-level norms of informal social control are important for determining crime at micro-places such as transit stations. The findings also indicate that urban design and transport policies require greater flexibility to enable intra-network variability in station design and formal security to enhance ridership.

This work highlights the importance of bis(triarylamine) redox-active linker in promoting the semiconductive and photoconductive behavior of a 2D zinc-based coordination polymer.

This study explored the sustainability of the stock market against the COVID-19 pandemic. The impacts of confirmed COVID-19 cases, COVID-19 deaths, and Movement Control Order (MCO) length on the stock market were examined. The Generalized Method of Moments (GMM) estimator was employed to analyze 57 countries’ weekly data from November 4th 2019 to July 5th 2020. The findings showed that the growth in confirmed COVID-19 cases has a significant negative effect on stock market returns, while the growth in COVID-19 deaths has a negative yet statistically insignificant influence on stock market returns. This study also found a non-linear inverted U-shaped relationship between the MCO period and stock market returns, implying that though the MCO has initial positive influences on the stock market, it negatively impacts the stock market after 5.7 weeks. Thus, this study argues that policy responses to the COVID-19 pandemic provide the most compelling explanation for its unprecedented impact on the sustainability of the stock market. Governments should therefore implement a partial lockdown to avoid deterioration of the national economy. Furthermore, government policies and plans to control the COVID-19 epidemic as well as economic stimulus packages to kickstart the economy play crucial roles in boosting economic growth and revitalizing the stock market

Contribution: Prior studies have shown that project-based learning (PBL) is an effective approach on engineering education. This study further identifies the impact of a design thinking (DT) integrated PBL approach on the college students' learning motivation and creativity. Background: A well-developed robot and its project often require interdisciplinary knowledge, such as design and technology, and interdisciplinary team collaboration to optimize the requirements of desirability and viability for developing products. The current study systematically embeds the elements of DT and PBL on a robot design course. Intended Outcomes: The DT PBL approach can improve the student's learning motivation and creativity in developing robots for engineering students. Application Design: A quasi-experimental design was used. Eighteen participants were assigned to the experimental group, whereas 23 participants were assigned to the comparison group. While the elements of DT and PBL were embedded into and delivered for the experimental group, the comparison group used a PBL-only approach. Findings: Evidence collected from quantitative survey/tests and qualitative interviews indicates that: 1) the experimental group outperformed the comparison group in overall learning motivation, and its subscales (task value and self-efficacy). The project enabled them to reflect on the insufficiency of required expertise and skills, which also helped them to learn more effectively and efficiently and 2) the experimental group outperformed the comparison group in overall creativity and its subscales (fluency, originality, and flexibility). The experimental group students can think faster, consider the problem through multiple perspectives, and come out with more creative ideas.

Background The seven-transmembrane (7TM) receptors are the largest superfamily of cell-surface receptors and are involved in various physiological processes of vertebrate species. In our previous study, a new chicken 7TM receptor (Ch-7TM) was discovered in mononuclear phagocytes (MNPs) derived from chicken peripheral blood mononuclear cells (PBMCs). To explore the functions of Ch-7TM, RNA interference (RNAi) was used to silence the Ch-7TM messenger RNA (mRNA) of MNPs, using small interface RNA (siRNA) designed with BLOCK-iT™ RNAi Designer. Results Herein we demonstrated that silencing of the Ch-7TM mRNA induced apoptosis of MNPs, suggesting that Ch-7TM contributed to the survival of MNPs. Moreover, chicken sera could inhibit the Ch-7TM-silencing-induced apoptosis in MNPs. The survival factor presented in fraction 16 (F16) of chicken sera was highly protective against the Ch-7TM-silencing-induced apoptosis in MNPs. The proteins from fraction 16 (F16) were identified as vitamin D-binding protein and apolipoprotein A-IV (ApoA-IV), which might be potential candidates for survival factors. Conclusions The protective effect of vitamin D and ApoA-IV indicated that Ch-7TM might involve the intracellular oxidation–reduction balance, although more evidence is needed to confirm this function. The siRNA screening serves as an excellent model for studying the functions of chicken MNPs receptors.

Photoconduction (PC) properties were investigated for ternary indium aluminium nitride (InxAl1-xN) nanorods (NRs) with different indium compositions (x) from 0.35 to 0.68, as grown by direct-current reactive magnetron sputter epitaxy. Cross-sectional scanning transmission electron microscopy (STEM) reveals single-crystal quality of the vertically aligned InxAl1-xN NRs. Single-rod photodetector devices with good ohmic contacts were fabricated using the focused-ion-beam technique (FIB), where the In-rich In0.68Al0.32N NR exhibits an optimal photocurrent responsivity of 1400 A W-1 and photoconductive gain of 3300. A transition from a positive photoresponse to a negative photoresponse was observed, while increasing the In composition x from 0.35 to 0.57. The negative PC was further enhanced by increasing x to 0.68. A model based on the coexistence and competition of deep electron trap states and recombination centers was proposed to explain the interesting composition-dependent PC in these ternary III-nitride 1D nanostructures. Funding Agencies|Ministry of Science and Technology. (MOST) of Taiwan [MOST 108-2628-M-011-001-MY3, MOST 109-2622-E-011-034, MOST 110-2622-E-011-017]; Swedish Research Council [2018-04198, 2021-00171, RIF21-0026]; Swedish Energy Agency [46658-1]; STINT Foundation [MG2019-8485]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [SFO-Mat-LiU 2009-00971]; Knut and Alice Wallenberg Foundation [KAW 2020.0033]; Swedish Foundation for Strategic Research [2021-00171, RIF21-0026]

This paper presents a technique for suppressing specific resonance modes of micromechanical resonators by mechanical means. In particular, attaching multiple miniaturized beam structures with properly designed dimensions acting as anti-resonating tuned mass dampers (TMD’s) to a micromechanical clamped-clamped beam (CC-beam) resonator based on a CMOS-MEMS process platform successfully attenuate the dynamic frequency response of the fundamental mode while retaining the $2^{\mathrm {nd}}$ harmonic mode of the CC-beam. The measured results show that the frequency transmission response of the TMD-embedded CC beam drops as much as $\sim 12$ dB compared to that of a reference resonator. An analytical model is used to study the effects of the parameter variations of the TMD structures. This technique provides an alternative approach to mechanically suppressing vibration modes for the micromechanical resonators that cannot employ the conventional quarter-wavelength support technique. [2020-0289]

In this paper we study the behavior of two buckled beams when they are pushed toward each other. The elastica model is adopted in the theoretical formulation. In the early stage, the buckled beams contact each other at one point. It then evolves to line contact when the external pushing force increases. The line-contact segment can be straight or curved. It is shown that there is no distributed force within the line-contact segment. In order to determine the stability of the deformation, the vibration method is adopted. To account for change of contact points during vibration, the equations of motion are reformulated into Eulerian forms and the squares of natural frequencies are solved. If any of the squares of natural frequencies is negative, the equilibrium is unstable. Experiments are conducted to measure the relation between the pushing force and the top clamp-line movement. For each stable deformation, several of the lowest natural frequencies are recorded and compared with the theoretical predictions. In displacement control the lowest two natural frequencies agree very well with the theoretical prediction. However, the measurement of natural frequencies for load control is less successful. Generally speaking, the deformation evolutions observed in experiments follow the load-deflection curves predicted theoretically for both displacement and load-control procedures.

For the High Energy Photon Source (HEPS), a green-field fourth-generation storage ring light source, the preliminary design report (PDR) was completed in 2018, when the accelerator physics design had been basically finished. During the subsequent hardware and engineering design of the HEPS storage ring based on the PDR design, a few problems and challenges emerged, calling for modifications of the lattice. In this paper, we will introduce the background and reasons for the modifications and present the linear optics and simulation results for the nonlinear performance of the modified lattice of the HEPS storage ring. The modified lattice satisfies the requirements from hardware and engineering design.

Cancer cells can enter quiescent or dormant state to resist anticancer agents while maintaining the potential of reactivation. However, the molecular mechanism underlying quiescence entry and reactivation remains largely unknown. In this paper, cancer cells eventually entered a reversible quiescent state to resist long-term paclitaxel (PTX) stress. The quiescent cells were characterized with Na+/H+ exchanger 1 (NHE1) downregulation and showed acidic intracellular pH (pHi). Accordingly, decreasing pHi by NHE1 inhibitor could induce cell enter quiescence. Further, acidic pHi could activate the ubiquitin-proteasome system and inhibiting proteasome activity by MG132 prevented cells entering quiescence. In addition, we show that after partial release, the key G1-S transcription factor E2F1 protein level was not recovered, while MCM7 protein returned to normal level in the reactivated cells. More importantly, MCM7 knockdown inhibited G1/S genes transcription and inhibited the reactivated proliferation. Taken together, this study demonstrates a regulatory function of intracellular acidification and subsequent protein ubiquitination on quiescence entry, and reveals a supportive effect of MCM7 on the quiescence-reactivated proliferation.

Plasmonic nanostructure/semiconductor nanohybrids offer many opportunities for emerging electronic and optoelectronic device applications because of their unique geometries in the nanometer scale and material properties. However, the development of a simple and scalable synthesis of plasmonic nanostructure/semiconductor nanohybrids is still lacking. Here, we report a direct synthesis of colloidal gold nanoparticle/graphene quantum dot (Au@GQD) nanohybrids under ambient conditions using microplasmas and their application as photoabsorbers for broad band photodetectors (PDs). Due to the unique AuNP core and graphene shell nanostructures in the synthesized Au@GQD nanohybrids, the plasmonic absorption of the AuNP core extends the usable spectral range of the photodetectors. It is demonstrated that the Au@GQD-based visible light photodetector simultaneously possesses an extraordinary photoresponsivity of ∼103 A/W, ultrahigh detectivity of 1013 Jones, and fast response time in the millisecond scale (65 ms rise time and 53 ms fall time). We suggest that the synergistic effect can be attributed to the strong fluorescence quenching in Au@GQD coupled with the two-dimensional graphene layer in the device. This work provides knowledge of tailoring the optical absorption in GQDs with plasmonic AuNPs and the corresponding photophysics for broad band response in PD-related devices.

Immune/stromal-associated genes may be promising biomarkers for cancer diagnosis and the determination of clinical cancer treatment options. The aim of the present study was to identify prognostic stromal/immune-associated genes in renal cell carcinoma (RCC). RCC gene expression data (885 cases) were obtained from The Cancer Genome Atlas database. Immune/stromal scores were calculated by using the ESTIMATE package in R. Immune/stromal scores were significantly associated with Tumor-Node-Metastasis stage, clinical stage and overall survival rate (P

Objective To evaluate the differences in the clinical effect and the safety in the treatment of post-stroke anxiety disorder (PSAD) between electroacupuncture (EA) and paroxetine on the base of the heart-brain theory. Methods A total of 70 patients of PSAD were randomized into an EA group and a medication group, 35 cases in each one. In the EA group, four acupoints were selected and divided into two pairs. In the Pair A, there were Baihui (百会 GV20) and Fēngfŭ (风府 GV16). In the Pair B, there were Xīnshū (心俞 BL15) and Shenmen (神门 HT7). After acupuncture, the electroacupuncture apparatus was applied. The duration of needle retention was 20 min. EA was given three times a week, totally for 4 weeks. In the medication group, paroxetine tablets were administered orally, 10 mg daily in the first 4 days and 20 mg afterwards, totally for 4 weeks. Before and after treatment, as well as in the follow-up period, Hamilton anxiety scale (HAMA), Barthel index (BI) for daily life ability, and clinical global impression (CGI) were observed and the clinical therapeutic effect was evaluated separately. Results A total of 3 cases were dropped-out in the medication group. Finally, 35 cases in the EA group and 32 cases in the medication group were included in the analysis. Compared with the scores before treatment, the scores of HAMA and CGI-SI (severity of illness) were lower and the scores of BI were higher after treatment and during the follow-up in either the EA group or the medication group (all P 0.05). Compared with the medication group, BI score in the EA group was higher in the follow-up, indicating the statistical significance (P Conclusions The therapeutic effect of electroacupuncture on the base of heart-brain theory is similar to the oral administration of paroxetine in the treatment of post-stroke anxiety disorder. This therapy relieves anxious emotions, promotes the recovery of limb function and has less adverse reactions in the patients.

The aim of this study is to develop a titanium three-dimensional (3D) printing novel hybrid suture anchor (HSA) with wing structure mechanism which can be opened to provide better holding power for surrounding osteoporotic bone. A screw-type anchor (5.5-mm diameter and 16-mm length) was designed with wing mechanism as well as micro dual-thread in the outer cortex bone contact area and macro single-thread in the anchor body. Both side wings can be opened by an internal screw to provide better bone holding power. The suture anchor and internal screw were manufactured using Ti6Al4V 3D printing and traditional machining, respectively. Static pullout and after dynamic 300-cyclic load (150 N) pullout tests for HSA with or without the wing open and commercial solid anchor (CSA) were performed (n = 5) in severely osteoporotic bone and osteoporotic bone to evaluate failure strengths. Comparison of histomorphometrical evaluation was performed through in vivo pig implantation of HSAs with the wing open and CSAs. The failure strengths of HSA with or without the wing open were 2.50/1.95- and 2.46/2.17-fold higher than those of CSA for static and after dynamic load pullout tests in severely osteoporotic bone, respectively. Corresponding values for static and after dynamic load pullout tests were 1.81/1.54- and 1.77/1.62-fold in osteoporotic bone, respectively. Histomorphometrical evaluation revealed that the effects of new bone ingrowth along the anchor contour for CSA and HSA were both approximately 20% with no significant difference. A novel HSA with wing mechanism was developed using 3D printing and the opened wing mechanism can be used to increase bone holding power for osteoporosis when necessary. Better failure strength of HSA than CSA under static and after dynamic load pullout tests and equivalence of bone ingrowth along the anchor contours confirmed the feasibility of the novel HSA.

Photoconductivity, a crucial property, determines the potential of semiconductor materials for use in optoelectronic and photocatalytic device applications. The one-dimensional metal-organic nanotube semiconducting material [{Re(CO)

This work aims to propose a promising locally resonating system consisting of a tensioned elastic membrane and two-arch masses attached on the membrane surface. Traditional membrane-type resonators, which usually create one obvious attenuation zone at low frequencies, might not be efficient in multi-frequency vibration suppression. The proposed structure can produce an extra clear flexural attenuation region and shift bandgap frequencies below 300 Hz. By adjusting geometric parameters (thickness, width, and location) of the arch mass, the bandgap region can be tuned. Introducing a feasible analytical model for accurately predicting the first and second initial frequencies of the bandgaps for a beam structure containing membrane-arch-mass resonators is another focus of this study. The proposed theoretical framework can be used to tune the bandgap to different target frequency ranges without knowing the actual width of the bandgap. Finite-element analysis and experiments are conducted to verify the theoretical predictions. A good agreement is seen among the theoretical, finite-element analysis, and experimental results. In addition, adjacent cells with different arch-mass distributions can generate two pairs of flexural bandgaps, increasing the practicality in engineering applications. The proposed structure might be used in low-frequency vibration isolation and filters.