Calcium single atoms stabilized by nitrogen coordination in metal-organic frameworks as efficient solid base catalysts.

Considerable attention has been paid to the preparation of single-atom solid base catalysts (SASBCs) owing to their high activity and maximized utilization of basic sites. At present, the reported fabrication methods of SASBCs, such as two-step reduction strategy and sublimation capture strategy, require high temperature. Such a high activation temperature is easy to cause the sublimation loss of alkali or alkaline earth metal atoms and destructive to the support structure. Herein, a new SASBC, Ca1/UiO-67-BPY, is fabricated, in which the alkaline earth metal Ca sites are immobilized onto N-rich metal-organic framework UiO-67-BPY at room temperature. The results show that the atomic configuration of Ca single atoms is coordinated by two N atoms in the framework. The obtained Ca SASBC possesses ordered structure and exhibits high product yield of 87.2% in the Knoevenagel reaction between benzaldehyde and malononitrile. Furthermore, thanks to the Ca single atoms sites anchored on UiO-67-BPY, the Ca1/UiO-67-BPY catalyst also shows good stability during cycles. This work might offer new insight in designing SASBCs for different base-catalyzed reactions.

Unveiling Chirality Transfer between Chiral Centers and Metal Halides in Chiral Organic-Inorganic Hybrid Metal Halides.

Chirality transfer refers to the process in which chiral cations compel the crystallization of the inorganic component into the Sohncke group. Enhancing the chirality of the inorganic component in chiral organic-inorganic hybrid metal halides (OIHMHs) through chirality transfer, aimed at improving chiroptical and spintronic properties, remains challenging due to the complexity of the underlying mechanism. To investigate this, we propose a novel concept─chirality transfer coefficient─as a means of quantifying the strength of chirality transfer in OIHMHs. A comparative study of OIHMHs with varying dimensionality, metal ions, and chiral centers was conducted to elucidate this mechanism. By analyzing factors such as hydrogen bonding, the number of chiral centers, dimensionality, helical geometry, and structural distortions, we found that chirality transfer is influenced by a combination of structural dimensions and the number of chiral centers. Importantly, our findings reveal that 0D, and 1D OIHMHs, particularly 1D with a zigzag chain configuration, exhibit stronger chirality transfer than their 2D counterparts. Moreover, in 2D OIHMHs, a reduction in the number of chiral centers enhances chirality transfer. However, no direct correlation was observed between chirality transfer and spin splitting. These insights contribute to a more comprehensive understanding of chirality transfer mechanisms and provide a strategic approach for enhancing the chirality transfer and associated physical properties in OIHMHs.

Causal Association of Golgi Protein 73 With Coronary Artery Disease: Evidence from Proteomics and Mendelian Randomization.

Background: Identification of the unknown pathogenic factor driving atherosclerosis not only enhances the development of disease biomarkers but also facilitates the discovery of new therapeutic targets, thus contributing to the improved management of coronary artery disease (CAD). We aimed to identify causative protein biomarkers in CAD etiology based on proteomics and 2-sample Mendelian randomization (MR) design. Methods: Serum samples from 33 first-onset CAD patients and 31 non-CAD controls were collected and detected using protein array. Differentially expressed analyses were used to identify candidate proteins for causal inference. We used 2-sample MR to detect the causal associations between the candidate proteins and CAD. Network MR was performed to explore whether metabolic risk factors for CAD mediated the risk of identified protein. Vascular expression of candidate protein in situ was also detected. Results: Among the differentially expressed proteins identified utilizing proteomics, we found that circulating Golgi protein 73 (GP73) was causally associated with incident CAD and other atherosclerotic events sharing similar etiology. Network MR approach showed low-density lipoprotein cholesterol and glycated hemoglobin serve as mediators in the causal pathway, transmitting 42.1% and 8.7% effects from GP73 to CAD, respectively. Apart from the circulating form of GP73, both mouse model and human specimens imply that vascular GP73 expression was also upregulated in atherosclerotic lesions and concomitant with markers of macrophage and phenotypic switching of vascular smooth muscle cells (VSMCs). Conclusions: Our study supported GP73 as a biomarker and causative for CAD. GP73 may involve in CAD pathogenesis mainly via dyslipidemia and hyperglycemia, which may enrich the etiological information and suggest future research direction on CAD.

Newcastle disease virus induces clathrin-mediated endocytosis to establish infection through the activation of PI3K/AKT signaling pathway by VEGFR2.

The phosphatidyl-inositol 3-kinase/serine-threonine kinase (PI3K/ AKT) signaling pathway constitutes a classical phosphorylation cascade that integrates tyrosine, lipid, and serine acid-threonine phosphorylation, affecting cell function. The pathway is vulnerable to viral infection. Newcastle disease virus (NDV) poses a significant threat to the global poultry industry; however, its mechanism of early viral cell invasion and pathogenesis remain unclear. Previous in vivo and in vitro studies have shown that NDV infection activates PI3K/AKT signaling; however, it remains unclear whether NDV establishes infection through endocytosis regulated by this pathway. This study aimed to examine whether different genotypes of NDV strains could activate the PI3K/AKT signaling pathway within 2 h of in vitro infection. This activation, which relies on PI3K phosphorylation, remains unaffected by the phosphorylation-phosphatase and tensin homolog/phosphatase and tensin homolog (p-PTEN/PTEN) signaling pathway. Moreover, inhibition of PI3K activity impedes NDV replication. Additionally, interfering with the PI3K regulatory subunit p85 has no significant effect on NDV replication. Conversely, the tyrosine kinase activity upstream of PI3K can influence AKT activation and viral replication, particularly through vascular endothelial growth factor receptor 2 (VEGFR2). Additionally, NDV F protein primarily mediates PI3K and AKT phosphorylation to activate the PI3K/AKT signaling pathway. NDV F and VEGFR2 proteins, along with the PI3K p85α subunit, interact and co-localize at the cell membrane. NDV-induced PI3K/AKT signaling pathway activation impacts clathrin-mediated endocytosis, with VEGFR2 playing a pivotal role. In conclusion, this study shows that NDV infection is established early through F protein binding to VEGFR2, activating the PI3K/AKT signaling pathway and inducing clathrin-mediated endocytosis, supporting infection prevention and control measures. IMPORTANCE: Newcastle disease virus (NDV) is a threat to the global poultry industry; however, the mechanisms of NDV infection remain unclear. NDV affects the phosphatidyl-inositol 3-kinase/serine-threonine kinase (PI3K/ AKT) signaling pathway, requiring endocytosis for successful infection. Based on previous studies, we identified a close correlation between NDV infection and replication and the PI3K/AKT signaling pathway activity. This study examined the molecular mechanisms through which NDV activates the PI3K/AKT signaling pathway to regulate endocytosis and facilitate infection. This study showed that early-stage in vitro NDV infection activated the PI3K/AKT signaling pathway, enhancing clathrin-mediated endocytosis, crucial for infection onset. Notably, this process involves the interaction between NDV F protein and the vascular endothelial growth factor receptor 2 tyrosine kinase, leading to the subsequent binding and phosphorylation of the PI3K p85α regulatory subunit. This activation primes PI3K, initiating a cascade that promotes clathrin-mediated endocytosis. Our findings elucidate how NDV capitalizes on the PI3K/AKT signaling pathway to establish infection through endocytosis.

SMYD5 is a ribosomal methyltransferase that catalyzes RPL40 lysine methylation to enhance translation output and promote hepatocellular carcinoma.

While lysine methylation is well-known for regulating gene expression transcriptionally, its implications in translation have been largely uncharted. Trimethylation at lysine 22 (K22me3) on RPL40, a core ribosomal protein located in the GTPase activation center, was first reported 27 years ago. Yet, its methyltransferase and role in translation remain unexplored. Here, we report that SMYD5 has robust in vitro activity toward RPL40 K22 and primarily catalyzes RPL40 K22me3 in cells. The loss of SMYD5 and RPL40 K22me3 leads to reduced translation output and disturbed elongation as evidenced by increased ribosome collisions. SMYD5 and RPL40 K22me3 are upregulated in hepatocellular carcinoma (HCC) and negatively correlated with patient prognosis. Depleting SMYD5 renders HCC cells hypersensitive to mTOR inhibition in both 2D and 3D cultures. Additionally, the loss of SMYD5 markedly inhibits HCC development and growth in both genetically engineered mouse and patient-derived xenograft (PDX) models, with the inhibitory effect in the PDX model further enhanced by concurrent mTOR suppression. Our findings reveal a novel role of the SMYD5 and RPL40 K22me3 axis in translation elongation and highlight the therapeutic potential of targeting SMYD5 in HCC, particularly with concurrent mTOR inhibition. This work also conceptually broadens the understanding of lysine methylation, extending its significance from transcriptional regulation to translational control.

Platelets promote primary hepatocellular carcinoma metastasis through TGF-ß1-mediated cancer cell autophagy.

Previous research has revealed that platelets promote tumor metastasis by binding to circulating tumor cells (CTCs). However, the role of platelets in epithelial-mesenchymal transition (EMT) of cancer cells at the primary tumor site, the crucial initial step of tumor metastasis, remains to be elucidated. Here, we found that platelet releasate enhanced EMT and motility of hepatocellular carcinoma (HCC) cells via AMPK/mTOR-induced autophagy. RNA-seq indicated that platelet releasate altered TGF-ß signaling pathway of cancer cells. Inhibiting TGFBR or deleting platelet TGF-ß1 suppressed AMPK/mTOR pathway activation and autophagy induced by platelet releasate. Compared with Pf4cre-; Tgfb1fl/fl mice, HCC orthotopic models established on Pf4cre+; Tgfb1fl/fl mice showed reduced TGF-ß1 in primary tumors, which corresponded with decreased cancer cell EMT, autophagy, migration ability and tumor metastasis. Inhibition of autophagy via Atg5 knockdown in cancer cells negated EMT and metastasis induced by platelet-released TGF-ß1. Clinically, higher platelet count correlated with increased TGF-ß1, LC3 and N-cad expression in primary tumors of HCC patients, suggesting a link between platelets and HCC progression. Our study indicates that platelets promote cancer cell EMT in the primary tumor and HCC metastasis through TGF-ß1-induced HCC cell autophagy via the AMPK/mTOR pathway. These findings offer novel insights into the role of platelets in HCC metastasis and the potential therapeutic targets for HCC metastasis.

Dual-function additive enables a self-regulatory mechanism to balance cathode-anode interface demands in Zn‖MnO2 batteries.

The poor reversibility of the zinc (Zn) anodes and the irreversible deposition/dissolution of Mn2+/MnO2 significantly impede the commercialization of Zn-Mn aqueous batteries (ZMABs). In reducing the difference between the desired interfacial reaction environments of the cathode and anode, we found that they face the same problem of interference-the generation of irreversible corrosion products. Herein, we have introduced a novel self-regulatory mechanism. This mechanism involves the addition of sodium dihydrogen phosphate, which shifts from passive protection to active regulation. It effectively captures OH- ions, prevents corrosion product formation, and facilitates the in situ generation of a solid electrolyte interface (SEI) film. This modification also homogenizes Zn ion flow and improves the reversibility of Zn plating and stripping. Furthermore, a stable and slightly acidic environment has been established to stabilize the pH at the cathodic interface, mitigate corrosion product formation, and enhance the reversible deposition and dissolution of Mn2+/MnO2. With the optimal electrolyte, Zn‖Zn symmetric cells demonstrate stable operation for over 3000 hours at 1 mA cm-2, 1 mA h cm-2. Additionally, the Zn‖Cu cells maintain high reversibility after 1000 cycles, achieving an average coulombic efficiency (CE) of 99.76%. The assembled Zn‖MnO2 full cells exhibit exceptional cycling stability and rate performance. This work adopts the approach of seeking common ground and emphasizing the balance of cathode and anode interfacial requirements, which represents a new and significant insight for design of ZMABs with high reversibility and high cyclability.

Andrographolide inhibits porcine epidemic diarrhea virus by inhibiting the JAK2-STAT3 pathway and promoting apoptosis.

Porcine epidemic diarrhea (PED) is an acute, virulent, and highly contagious disease caused by the porcine epidemic diarrhea virus (PEDV). The high mutation rate of PEDV makes it difficult to effectively control using traditional vaccines, emphasizing the need for novel anti-PEDV-specific drugs. Therefore, this study aimed to investigate the activity and mechanism of action of andrographolide (AND) against PEDV in vitro and in vivo. In vitro experiments showed that AND treatment significantly inhibited PEDV replication in a cell model. The mechanism is that AND treatment significantly suppressed PEDV-induced activation of the JAK2-STAT3 pathway, which promoted apoptosis and inhibited the proliferation of the virus. Moreover, PEDV-infected 3-day-old piglets were treated with AND, and clinical symptoms, intestinal morphology, and viral load were examined. In vivo experiments showed that AND treatment reduced clinical symptoms, ameliorated intestinal damage, and increased the survival rate of infected piglets by 16.7 %. Conclusively, this study contributes to the field of PEDV antiviral drug development and provides new directions for PED prevention and treatment.

Network of Interactions between the Mut Domains of the E2 Protein of Atypical Porcine Pestivirus and Host Proteins.

Atypical porcine pestivirus (APPV) can cause congenital tremor type A-II in neonatal piglets, posing a significant threat to swine herd health globally. Our previous study demonstrated that the Mut domains, comprising 112 amino acids at the N-terminus, are the primary functional regions of the E2 protein of APPV. This study identified 14 host cellular proteins that exhibit potential interactions with the Mut domains of the E2 protein using yeast two-hybrid screening. Using bioinformatics analysis, we discovered that the Mut domains of the E2 protein might exert regulatory effects on apoptosis by modulating energy metabolism within the mitochondria. We also conducted co-immunoprecipitation, glutathione S-transferase pull-down, and immunofluorescence assays to confirm the interaction between the Mut domains of the E2 protein and cathepsin H and signal sequence receptor subunit 4 (SSR4). Ultimately, SSR4 enhanced APPV replication in vitro. In summary, our study successfully elucidated the interactions between the Mut domains of the E2 protein and host cell protein, predicted the potential pathways implicated in these interactions, and demonstrated SSR4 involvement in APPV infection. These significant findings contribute valuable knowledge toward a deeper understanding of APPV pathogenesis and the role of the Mut domains of the E2 protein in this intricate process.

Safety of low-intensity extracorporeal shock wave therapy in prostate disorders: in vitro and in vivo evidence.

ABSTRACT: Recent evidence suggests that low-intensity extracorporeal shock wave therapy (Li-ESWT) is a promising treatment for chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS); however, its safety in pelvic organs, particularly prostate tissues and cells, remains unclear. The current study evaluates the risks of prostate cell damage or oncogenesis following the administration of Li-ESWT for prostatitis. To this end, a robust in vitro model (Cell Counting Kit-8 [CCK-8] assay, clone formation assay, cell scratch assay, lactate dehydrogenase [LDH] release assay, flow cytometry, and immunoblotting assay) was designed to examine the effects of Li-ESWT on cell proliferation, clonogenicity, migration, membrane integrity, and DNA damage. Exome sequencing of Li-ESWT-treated cells was performed to determine the risk of carcinogenesis. Furthermore, an in vivo rat model ( n = 20) was employed to assess the effects of Li-ESWT on cancer biomarkers (carcinoembryonic antigen [CEA], Ki67, proliferating cell nuclear antigen [PCNA], and gamma-H2A histone family member X, phosphorylation of the H2AX Ser-139 [ γ -H2AX]) in prostate tissue. Based on our findings, Li-ESWT promotes cellular growth and motility without inducing significant cell membrane or DNA damage or alterations. Genetic analyses did not demonstrate an increase in mutations, and no damage to prostate tissue or upregulation of cancer biomarkers was detected in vivo. This comprehensive in vitro and in vivo assessment confirms the safety of Li-ESWT in managing prostate disorders.

Twin-Field Quantum Key Distribution with Local Frequency Reference.

Twin-field quantum key distribution (TFQKD) overcomes the linear rate-loss limit, which promises a boost of secure key rate over long distance. However, the complexity of eliminating the frequency differences between the independent laser sources hinders its practical application. We analyzed and determined the frequency stability requirements for implementing TFQKD using frequency-stabilized lasers. Based on this analysis, we proposed and demonstrated a simple and practical approach that utilizes the saturated absorption spectroscopy of acetylene as an absolute reference, eliminating the need for fast frequency locking to achieve TFQKD. Adopting the 4-intensity sending-or-not-sending TFQKD protocol, we experimentally demonstrated the TFQKD over 502, 301, and 201 km ultralow-loss optical fiber, respectively. We expect this high-performance scheme will find widespread usage in future intercity and free-space quantum communication networks.

Genetic and molecular characterization of H9N2 avian influenza viruses in Yunnan Province, Southwestern China.

The H9N2 subtype of the avian influenza virus (AIV) is widely prevalent in birds, threatening the poultry industry and providing genetic material for emerging human pathogens. The prevalence and genetic characteristics of H9N2 in Yunnan Province, China, are largely unknown. Samples were collected from live poultry markets (LPMs) and breeding farms in Yunnan Province. H9N2-positive samples were identified by polymerase chain reaction (PCR), with a high positivity rate of 42.86% in tissue samples. The positivity rate of swab samples in the LPMs in Kunming was 3.97% (17/564), but no AIV was detected in samples from poultry farms in Lijiang, Wenshan, and Yuxi. Evolutionary analysis and genotyping were performed for the 17 strains of isolated H9N2 virus. Phylogenetic analysis revealed that all H9N2 viral genes had 91.6%-100% nucleotide homology, belonged to the G57 genotype, and had high homology with H9N2 viruses isolated from Guangdong and Guangxi, suggesting that the H9N2 viruses in Yunnan Province may have been imported by chicks. Using a nucleotide divergence cutoff of 95%, we identified ten distinct H9N2 genotypes that continued to evolve. The surface genes of the H9N2 isolates displayed substantial genetic diversity, highlighting the genetic diversity and complexity of the H9N2-subtype AIVs in Yunnan. Molecular analysis demonstrated that all 17 strains of H9N2 isolates had mutations at H183N, Q226L, L31P, and I268V in hemagglutinin; S31N in matrix protein 2; and no replacements at positions 274 and 292 of the neuraminidase protein. Sixteen strains had the A558V mutation and one strain had the E627V mutation in polymerase basic protein 2. Analysis of these amino acid sites suggests that H9N2 influenza viruses in Yunnan continue to mutate and adapt to mammals and are sensitive to neuraminidase inhibitors but resistant to adamantanes. It is necessary to strengthen surveillance of AIV H9N2 subtypes in poultry and LPMs in Yunnan to further understand their genetic diversity.

Coupled Kite-to-Square Distortion Transition and Physical Properties in 2D Lead Halide Perovskite.

2D lead halide perovskites showcase diverse electrical and optoelectrical properties due to their adaptable structural distortion, which dictates the symmetry characteristics of the material. To accommodate the geometric shape of the cation, the inorganic layer of the 2D perovskite often undergoes specific distortions such as lead-halide bond length elongation/compression and lead atom displacement. The resultant distortion manifests as a quadrilateral shape formed by Pb atoms from four adjacent four octahedrons. The degree of distortion increases as the quadrilateral deviates further from a square shape and vice versa. This quadrilateral shape not only visually represents the magnitude of distortion but also confirms its direction. During the transition from kite to square distortion under external stimuli, the positions of the Pb atoms vividly illustrate the symmetry-breaking process, corresponding to a shift from high to low symmetry states. The electrical and optoelectronic properties, including ferroelectricity, pyroelectricity, piezoelectricity, nonlinear optical properties, and characteristics related to bulky photovoltaic effects, some of them exhibit direction dependence nature. This perspective employed a visible structural distortion approach to elucidate symmetry breaking and coupling distortion transitions with eight optoelectronic physical properties in 2D layered perovskite. We review recent research advancements and outline current challenges that help us to understand the structure-property relationship of 2D perovskite.

Unconventional Magnetic and Magneto-Transport Properties in Quasi-2D Ni0.28TaSeS Single Crystal.

Van der Waals (vdW) magnetic materials have broad application prospects in next-generation spintronics. Inserting magnetic elements into nonmagnetic vdW materials can introduce magnetism and enhance various transport properties. Herein, the unconventional magnetic and magneto-transport phenomena is reported in Ni0.28TaSeS crystal by intercalating Ni atoms into nonmagnetic 2H-TaSeS matrix. Magnetic characterization reveals a canted magnetic structure in Ni0.28TaSeS, which results in an antiferromagnetic (AFM) order along the c-axis and a ferromagnetic (FM) moment in the ab-plane. The presence of spin-flop (SF) behavior can also be attributed to the canted magnetic structure. Temperature-dependent resistivity exhibits a metallic behavior with an abrupt decrease corresponding to the magnetic transition. Magneto-transport measurements demonstrate a positive magnetoresistance (MR) with a plateau that is different from conventional magnetic materials. The field-dependent Hall signal exhibits nonlinear field dependence when the material is in magnetically ordered state. These unconventional magneto-transport behaviors are attributed to the field-induced formation of a complex spin texture in Ni0.28TaSeS. In addition, it further investigated the angle dependence of MR and observed an unusual fourfold anisotropic magnetoresistance (AMR) effect. This work inspires future research on spintronic devices utilizing magnetic atom-intercalated quasi-2D materials.

Multi-omic analysis reveals that Bacillus licheniformis enhances pekin ducks growth performance via lipid metabolism regulation.

Introduction: Bacillus licheniformis (B.licheniformis) was widely used in poultry feeds. However, it is still unclear about how B.licheniformis regulates the growth and development of Pekin ducks. Methods: The experiment was designed to clarify the effect and molecular mechanism of B. licheniformis on the lipid metabolism and developmental growth of Pekin ducks through multiomics analysis, including transcriptomic and metabolomic analyses. Results: The results showed that compared with the control group, the addition of 400 mg/kg B. licheniformis could significantly increase the body weight of Pekin ducks and the content of triglyceride (p < 0.05), at the same time, the addition of B. licheniformis could affect the lipid metabolism of liver in Pekin ducks, and the addition of 400 mg/kg B. licheniformis could significantly increase the content of lipoprotein lipase in liver of Pekin ducks. Transcriptomic analysis revealed that the addition of B. licheniformis primarily impacted fatty acid and glutathione, amino acid metabolism, fatty acid degradation, as well as biosynthesis and elongation of unsaturated fatty acids. Metabolomic analysis indicated that B. licheniformis primarily affected the regulation of glycerol phospholipids, fatty acids, and glycerol metabolites. Multiomics analysis demonstrated that the addition of B. licheniformis to the diet of Pekin ducks enhanced the regulation of enzymes involved in fat synthesis via the PPAR signaling pathway, actively participating in fat synthesis and fatty acid transport. Discussion: We found that B. licheniformis effectively influences fat content and lipid metabolism by modulating lipid metabolism-associated enzymes in the liver. Ultimately, this study contributes to our understanding of how B. licheniformis can improve the growth performance of Pekin ducks, particularly in terms of fat deposition, thereby providing a theoretical foundation for its practical application. Conclusion: B. licheniformis can increase the regulation of enzymes related to fat synthesis through PPAR signal pathway, and actively participate in liver fat synthesis and fatty acid transport, thus changing the lipid metabolism of Pekin ducks, mainly in the regulation of glycerol phospholipids, fatty acids and glycerol lipid metabolites.

Nucleotide metabolism-related host proteins RNA polymerase II subunit and uridine phosphorylase 1 interacting with porcine epidemic diarrhea virus N proteins affect viral replication.

Porcine epidemic diarrhea virus (PEDV) is a highly infectious pathogen that targets pig intestines to cause disease. It is globally widespread and causes huge economic losses to the pig industry. PEDV N protein is the protein that constitutes the core of PEDV virus particles, and most of it is expressed in the cytoplasm, and a small part can also be expressed in the nucleus. However, the role of related proteins in host nucleotide metabolic pathways in regulating PEDV replication have not been fully elucidated. In this study, PEDV-N-labeled antibodies were co-immunoprecipitated and combined with LC-MS to screen for host proteins that interact with N proteins. Bioinformatics analyses showed that the selected host proteins were mainly enriched in metabolic pathways. Moreover, co-immunoprecipitation and confocal microscopy confirmed that the second-largest subunit of RNA polymerase II (RPB2) and uridine phosphorylase 1 (UPP1) interacted with the N protein. RPB2 is the main subunit of RNA polymerase II and plays an important role in eukaryotic transcription. UPP1 is an enzyme that catalyzes reversible phosphorylation of uridine to uracil and ribo-1-phosphate to promote catabolism and bio anabolism. RPB2 overexpression significantly promoted viral replication, whereas UPP1 overexpression significantly inhibited viral replication. Studies on interactions between the PEDV N and host proteins are helpful in elucidating the pathogenesis and immune escape mechanism of PEDV.

Shape Shifting and Locking in Mechanically Responsive Organic-Inorganic Hybrid Materials for Thermoelastic Actuators.

The construction of mechanically responsive materials with reversible shape-shifting, shape-locking, and stretchability holds promise for a wide range of applications in fields such as soft robotics and flexible electronics. Here, we report novel thermoelastic one-dimensional organic-inorganic hybrids (R/S-Hmpy)PbI3 (Hmpy=2-hydroxymethyl-pyrrolidinium) to show mechanical responses. The single crystals undergo two phase transitions at 310 K and 380 K. When heated to 380 K, they show shape-shifting and expansion along the b-axis by about 13.4 %, corresponding to a larger deformation than that of thermally activated shape memory alloys (8.5 %), and exhibit a strong actuation force. During the cooling process, the stretched crystal shape maintains and a shape-locking phenomenon occurs, which is lifted when the temperature decreases to 305 K. Meanwhile, due to the introduction of chiral ions, the thermal switching shows a 10-fold second-order nonlinear switching contrast (common values typically below 3-fold). This study presents a thermoelastic actuator based on shape-shifting and -locking of organic-inorganic hybrids for the first time. The dielectric and nonlinear optical switching properties of organic-inorganic hybrids broaden the range of applications of mechanically responsive crystals.

Effect of artificial natural light on the development of myopia among primary school-age children in China: a three-year longitudinal study.

AIM: To assess the efficacy of artificial natural light in preventing incident myopia in primary school-age children. METHODS: This is a prospective, randomized control, intervention study. A total of 1840 students from 39 classes in 4 primary schools in Foshan participated in this study. The whole randomization method was adopted to include classes as a group according to 1:1 randomized control. Classrooms in the control group were illuminated by usual light, and classrooms in the intervention group were illuminated by artificial natural light. All students received uncorrected visual acuity and best-corrected visual acuity measurement, non-cycloplegic autorefraction, ocular biometric examination, slit lamp and strabismus examination. Three-year follow-up, the students underwent same procedures. Myopia was defined as spherical equivalent refraction ≤ -0.50 D and uncorrected visual acuity <20/20. RESULTS: There were 894 students in the control group and 946 students in the intervention group with a mean±SD age of 7.50±0.53y. The three-year cumulative incidence rate of myopia was 26.4% (207 incident cases among 784 eligible participants at baseline) in the control group and 21.2% (164 incident cases among 774 eligible participants at baseline) in the intervention group [difference of 5.2% (95%CI, 3.7% to 10.1%); P=0.035]. There was also a significant difference in the three-year change in spherical equivalent refraction for the control group (-0.81 D) compared with the intervention group [-0.63 D; difference of 0.18 D (95%CI, 0.08 to 0.28 D); P<0.001]. Elongation of axial length was significantly different between in the control group (0.77 mm) and the intervention group [0.72 mm; difference of 0.05 mm (95%CI, 0.01 to 0.09 mm); P=0.003]. CONCLUSION: Artificial natural light in the classroom of primary schools can result in reducing incidence rate of myopia during a period of three years.