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The perovskite structure accommodates many different combinations of elements, making it attractive for use in a wide variety of applications. Building perovskites out of only organic compounds is appealing because these materials tend to be flexible, fracture-resistant, and potentially easier to synthesize than their inorganic counterparts. Ye et al. describe a previously unknown family of all-organic perovskites, of which they synthesized 23 different family members (see the Perspective by Li and Ji). The compounds are attractive as ferroelectrics, including one compound with properties close to the well-known inorganic ferroelectric BaTiO 3 . Science , this issue p. 151 ; see also p. 132 A family of all-organic perovskites has attractive ferroelectric properties. Inorganic perovskite ferroelectrics are widely used in nonvolatile memory elements, capacitors, and sensors because of their excellent ferroelectric and other properties. Organic ferroelectrics are desirable for their mechanical flexibility, low weight, environmentally friendly processing, and low processing temperatures. Although almost a century has passed since the first ferroelectric, Rochelle salt, was discovered, examples of highly desirable organic perovskite ferroelectrics are lacking. We found a family of metal-free organic perovskite ferroelectrics with the characteristic three-dimensional structure, among which MDABCO ( N -methyl- N' -diazabicyclo[2.2.2]octonium)–ammonium triiodide has a spontaneous polarization of 22 microcoulombs per square centimeter [close to that of barium titanate (BTO)], a high phase transition temperature of 448 kelvins (above that of BTO), and eight possible polarization directions. These attributes make it attractive for use in flexible devices, soft robotics, biomedical devices, and other applications.

Piezoelectric materials produce electricity when strained, making them ideal for different types of sensing applications. The most effective piezoelectric materials are ceramic solid solutions in which the piezoelectric effect is optimized at what are termed morphotropic phase boundaries (MPBs). Ceramics are not ideal for a variety of applications owing to some of their mechanical properties. We synthesized piezoelectric materials from a molecular perovskite (TMFM)ₓ(TMCM)1–x CdCl₃ solid solution (TMFM, trimethylfluoromethyl ammonium; TMCM, trimethylchloromethyl ammonium, 0 ≤ x ≤ 1), in which the MPB exists between monoclinic and hexagonal phases. We found a composition for which the piezoelectric coefficient d 33 is ∼1540 picocoulombs per newton, comparable to high-performance piezoelectric ceramics. The material has potential applications for wearable piezoelectric devices.

Natural organic sulfides are predominantly found in cruciferous and liliaceous plants. Among these compounds, alliin—an organic sulfide derived from garlic—has garnered significant attention from researchers due to its potential anti-atherosclerotic properties. However, studies specifically investigating the anti-atherosclerotic effects of alliin remain limited. This study aims to elucidate the protective effects of alliin on ox-LDL-injured human umbilical vein endothelial cells (HUVECs) and their underlying mechanisms. Initially, HUVECs were exposed to 80 mg/L oxidized low-density lipoprotein (ox-LDL) for 24 h to establish an ox-LDL injury model. Subsequently, the Cell Counting Kit-8 (CCK8) assay was utilized to assess the effect of alliin on the proliferation of ox-LDL-injured cells at 12, 24 and 48 h, and the levels of total cholesterol (TC) and free cholesterol (Fch) in the HUVECs were measured according to the instructions of TC and Fch kits. Next, quantitative proteomics was then adopted to analyze the differential protein expression in cell samples from the control group (Con), the ox-LDL injury model group (Mod), and the alliin treatment group (Alliin). Among the quantified proteins, a statistical t-test with P  < 0.05 was used as a threshold for significance regarding a 1.5-fold change in differential expression. Finally, functional enrichment analysis of the differential proteins in the Alliin/Mod group was performed using Gene Ontology (GO) enrichment and KEGG pathway analysis. Additionally, Western blotting was used to validate the findings. The proteomic analysis identified 6173 identified proteins, of which 5162 were quantifiable. Differential protein analysis revealed that in the Alliin/Con comparison, there were a total of 108 up-regulated proteins and 116 down-regulated proteins; in the Alliin/Mod comparison there were a total of 33 up-regulated proteins and 17 down-regulated proteins; while in the Mod/Con comparison, there were a total of 106 up-regulated proteins and 147 down-regulated proteins. GO enrichment, KEGG pathway analyses and Western blotting verification demonstrated that alliin up-regulates the expression of Low-density lipoprotein receptor (LDLR) ( P  < 0.05) and apolipoprotein C (ApoC) ( P  < 0.05) while down-regulating the expression of apolipoprotein B (ApoB) ( P  < 0.05) to regulate the cholesterol metabolism pathway of the ox-LDL-injured HUVECs. Our findings highlight the importance of cholesterol metabolism in alliin treatment for atherosclerosis. Alliin exerts a protective effect in the ox-LDL-induced HUVEC injury model by modulating the expression of LDLR, ApoC, and ApoB within the cholesterol metabolism pathway. These findings indicate that alliin could potentially serve as a therapeutic agent for the prevention and treatment of atherosclerosis.

Psychological well-being is a core feature of mental health, and may be defined as including hedonic (enjoyment, pleasure) and eudaimonic (meaning, fulfillment) happiness, as well as resilience (coping, emotion regulation, healthy problem solving). To promote psychological well-being, it is helpful to understand the underlying mechanisms associated with this construct and then develop targeted and effective training programs. In this perspective article, we discuss key components and potential brain-body mechanisms related to psychological well-being and propose mindfulness training as a promising way to improve it. Based on a series of randomized controlled trial (RCT) studies of one form of mindfulness training in adolescents and adults, the integrative body-mind training (IBMT), we use IBMT as an exemplar to provide research evidence of the positive effects of mindfulness training on psychological well-being. We focus on one of the mechanisms by which IBMT enhances psychological well-being-the interaction between mind (mindfulness) and body (bodifulness)-which involves both the central nervous system (CNS) and the autonomic nervous system (ANS). We also highlight the role of brain self-control networks, including the anterior cingulate cortex/prefrontal cortex (ACC/PFC), in improving psychological well-being. We suggest that mindfulness training may be a promising program that promotes the synergistic engagement of mind and body to achieve the goals of enhancing psychological well-being.

Shape memory alloys have been used extensively in actuators, couplings, medical guide wires, and smart devices, because of their unique shape memory effect and superelasticity triggered by the reversible martensitic phase transformations. For ferroic materials, however, almost no memory effects have been found for their ferroic domains after reversible phase transformations. Here, we present a pair of single-component organic enantiomorphic ferroelectric/ferroelastic crystals, ( R )- and ( S )- N -3,5-di- tert -butylsalicylidene-1-(1-naphthyl)ethylamine SA-NPh-( R ) and SA-NPh-( S ). It is notable that not only can their ferroic domain patterns disappear and reappear during reversible thermodynamic phase transformations, but they can also disappear and reappear during reversible light-driven phase transformations induced by enol–keto photoisomerization, both of which are from P 1 to P 2 1 polar space groups. Most importantly, the domain patterns are exactly the same in the initial and final states, demonstrating the existence of a memory effect for the ferroic domains in SA-NPh-( R ) and SA-NPh-( S ). As far as we are aware, the domain memory effect triggered by both thermodynamic and light-driven ferroelectric/ferroelastic phase transformations remains unexplored in ferroic materials. Thermal and optical control of domain memory effect would open up a fresh research field for smart ferroic materials. Memory effect is seldom found in ferroic domains after reversible phase transformations. Here, the authors develop a pair of single-component organic enantiomorphic multiferroic crystals with erasable ferroelectric and ferroelastic domains.

In anilines and benzylic amines, a recyclable chemical template can direct the olefination and acetoxylation of meta -C–H bonds as far as 11 bonds away from a functional group; in particular, it is able to direct the meta -selective C–H functionalization of bicyclic heterocycles via a highly strained, tricyclic-cyclophane-like palladated intermediate. Site selective remote C–H bond activation To fully realize the synthetic potential of carbon–hydrogen (C–H) bond activation in organic chemistry, it is important to develop new approaches that can activate C–H bonds selectively in various locations with respect to existing functional groups. In this paper, Jin-Quan Yu and colleagues use a recyclable template to direct the olefination and acetoxylation of remote meta -C–H bonds — up to eleven bonds away — of anilines and benzylic amines. This template is able to direct the meta -selective C–H functionalization of tetrahydroquinoline, benzoxazines, anilines, benzylamines, 2-phenylpyrrolidines and 2-phenylpiperidines, all of which are commonly used building blocks in drug discovery. Achieving site selectivity in carbon–hydrogen (C–H) functionalization reactions is a long-standing challenge in organic chemistry. The small differences in intrinsic reactivity of C–H bonds in any given organic molecule can lead to the activation of undesired C–H bonds by a non-selective catalyst. One solution to this problem is to distinguish C–H bonds on the basis of their location in the molecule relative to a specific functional group. In this context, the activation of C–H bonds five or six bonds away from a functional group by cyclometallation has been extensively studied 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 . However, the directed activation of C–H bonds that are distal to (more than six bonds away) functional groups has remained challenging, especially when the target C–H bond is geometrically inaccessible to directed metallation owing to the ring strain encountered in cyclometallation 14 , 15 . Here we report a recyclable template that directs the olefination and acetoxylation of distal meta -C–H bonds—as far as 11 bonds away—of anilines and benzylic amines. This template is able to direct the meta -selective C–H functionalization of bicyclic heterocycles via a highly strained, tricyclic-cyclophane-like palladated intermediate. X-ray and nuclear magnetic resonance studies reveal that the conformational biases induced by a single fluorine substitution in the template can be enhanced by using a ligand to switch from ortho - to meta -selectivity.

Molecular ferroelectrics are currently an active research topic in the field of ferroelectric materials. As complements or alternatives of conventional inorganic ferroelectrics, they have been designed to realize various novel properties, ranging from multiferroicity and semiconductive ferroelectricity to ferroelectric photovoltaics and ferroelectric luminescence. The stabilizing of ferroelectricity in various systems is owing to the flexible tailorability of the organic components. Here we describe the construction of optically active molecular ferroelectrics by introducing homochiral molecules as polar groups. We find that the ferroelectricity in ( R )-(−)-3-hydroxlyquinuclidinium halides is due to the alignment of the homochiral molecules. We observe that both the specific optical rotation and rotatory direction change upon paraelectric-ferroelectric phase transitions, due to the existence of two origins from the molecular chirality and spatial arrangement, whose contributions vary upon the transitions. The optical rotation switching effect may find applications in electro-optical elements. Ferroelectric phase transitions are normally accompanied by structural changes in the materials. Here, Li et al . synthesize homochiral molecular crystals and utilize their ferroelectric transitions to achieve optical switches with different refractive indices for left- and right-handed polarizations.

Proteins in cellular environments are highly susceptible. Local perturbations to any residue can be sensed by other spatially distal residues in the protein molecule, showing long-range correlations in the native dynamics of proteins. The long-range correlations of proteins contribute to many biological processes such as allostery, catalysis, and transportation. Revealing the structural origin of such long-range correlations is of great significance in understanding the design principle of biologically functional proteins. In this work, based on a large set of globular proteins determined by X-ray crystallography, by conducting normal mode analysis with the elastic network models, we demonstrate that such long-range correlations are encoded in the native topology of the proteins. To understand how native topology defines the structure and the dynamics of the proteins, we conduct scaling analysis on the size dependence of the slowest vibration mode, average path length, and modularity. Our results quantitatively describe how native proteins balance between order and disorder, showing both dense packing and fractal topology. It is suggested that the balance between stability and flexibility acts as an evolutionary constraint for proteins at different sizes. Overall, our result not only gives a new perspective bridging the protein structure and its dynamics but also reveals a universal principle in the evolution of proteins at all different sizes.

Within a short period of time, COVID-19 grew into a world-wide pandemic. Transmission by pre-symptomatic and asymptomatic viral carriers rendered intervention and containment of the disease extremely challenging. Based on reported infection case studies, we construct an epidemiological model that focuses on transmission around the symptom onset. The model is calibrated against incubation period and pairwise transmission statistics during the initial outbreaks of the pandemic outside Wuhan with minimal non-pharmaceutical interventions. Mathematical treatment of the model yields explicit expressions for the size of latent and pre-symptomatic subpopulations during the exponential growth phase, with the local epidemic growth rate as input. We then explore reduction of the basic reproduction number R 0 through specific transmission control measures such as contact tracing, testing, social distancing, wearing masks and sheltering in place. When these measures are implemented in combination, their effects on R 0 multiply. We also compare our model behaviour to the first wave of the COVID-19 spreading in various affected regions and highlight generic and less generic features of the pandemic development. Transmission by pre-symptomatic and asymptomatic viral carriers makes intervention and containment of the COVID-19 extremely challenging. Here, the authors construct an epidemiological model that focuses on transmission around the symptom onset, exploring specific transmission control measures.

China has the highest global prevalence of cigarette smokers, accounting for more than 40% of the total cigarette consumption in the world. Considering the shortage of smoking cessation services in China, and the acceptability, feasibility, and efficacy of mobile-phone-based text messaging interventions for quitting smoking in other countries, we conducted a mobile-phone-based smoking cessation study in China. We conducted a randomized controlled trial in China across 30 cities and provinces from August 17, 2016, to May 27, 2017. Adult smokers aged 18 years and older with the intention to quit smoking were recruited and randomized to a 12-week high-frequency messaging (HFM) or low-frequency messaging (LFM) intervention (\"Happy Quit\") or to a control group in a 5:2:3 ratio. The control group received only text messages unrelated to quitting. The primary outcome was biochemically verified continuous smoking abstinence at 24 weeks. Secondary outcomes included (1) self-reported 7-day point prevalence of abstinence (i.e., not even a puff of smoke, for the last 7 days) at 1, 4, 8, 12, 16, 20, and 24 weeks; (2) self-reported continuous abstinence at 4, 12, and 24 weeks; and (3) self-reported average number of cigarettes smoked per day. A total of 1,369 participants received 12 weeks of intervention or control text messages with continued follow-up for 12 weeks. The baseline characteristics of participants among the HFM (n = 674), LFM (n = 284), and control (n = 411) groups were similar. The study sample included 1,295 (94.6%) men; participants had a mean age of 38.1 (SD 9.79) years and smoked an average of 20.1 (SD 9.19) cigarettes per day. We included the participants in an intention-to-treat analysis. Biochemically verified continuous smoking abstinence at 24 weeks occurred in 44/674 participants in the HFM group (6.5%), 17/284 participants in the LFM group (6.0%), and 8/411 participants (1.9%) in the control group; participants in both the HFM (odds ratio [OR] = 3.51, 95% CI 1.64-7.55, p < 0.001) and the LFM (OR = 3.21, 95% CI 1.36-7.54], p = 0.002) intervention groups were more likely to quit smoking than those in the control group. However, there was no difference in quit rate between the HFM and LFM interventions. We also found that the 7-day point quit rate from week 1 to week 24 ranged from approximately 10% to more than 26% with the intervention and from less than 4% to nearly 12% without the intervention. Those who continued as smokers in the HFM group smoked 1 to 3 fewer cigarettes per day than those in the LFM group over the 24 weeks of trial. Among study limitations, the participants were able to use other smoking cessation services (although very few participants reported using them), cotinine tests can only detect smoking status for a few days, and the proportion of quitters was small. Our findings demonstrate that a mobile-phone-based text messaging intervention (Happy Quit), with either high- or low-frequency messaging, led to smoking cessation in the present study, albeit in a low proportion of smokers, and can therefore be considered for use in large-scale intervention efforts in China. Mobile-phone-based interventions could be paired with other smoking cessation services for treatment-seeking smokers in China. ClinicalTrials.gov NCT02693626.