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Perinatal and childhood adverse outcomes associated with assisted reproductive technology (ART) has been reported, but it remains unknown whether the initial leukocyte telomere length (LTL), which is an indicator of age-related phenotypes in later life, is affected. Here, we estimated the LTLs of 1,137 individuals from 365 families, including 202 children conceived by ART and 205 children conceived spontaneously from two centers of the China National Birth Cohort, using whole-genome sequencing (WGS) data. One-year-old children conceived by ART had shorter LTLs than those conceived spontaneously (beta, -0.36; P = 1.29 × 10

The circadian rhythm generates out-of-equilibrium metabolite oscillations that are controlled by feedback loops under light/dark cycles. Here we describe a non-equilibrium nanosystem comprising a binary population of enzyme-containing polymersomes capable of light-gated chemical communication, controllable feedback and coupling to macroscopic oscillations. The populations consist of esterase-containing polymersomes functionalized with photo-responsive donor–acceptor Stenhouse adducts (DASA) and light-insensitive semipermeable urease-loaded polymersomes. The DASA–polymersome membrane becomes permeable under green light, switching on esterase activity and decreasing the pH, which in turn initiates the production of alkali in the urease-containing population. A pH-sensitive pigment that absorbs green light when protonated provides a negative feedback loop for deactivating the DASA–polymersomes. Simultaneously, increased alkali production deprotonates the pigment, reactivating esterase activity by opening the membrane gate. We utilize light-mediated fluctuations of pH to perform non-equilibrium communication between the nanoreactors and use the feedback loops to induce work as chemomechanical swelling/deswelling oscillations in a crosslinked hydrogel. We envision possible applications in artificial organelles, protocells and soft robotics.

Van der Waals heterostructures composed of low-dimensional atomic layers host rich physics for new device applications, such as magic-angle twisted bilayer graphene and coaxial multi-walled hetero-nanotubes. Aside from exploring their abnormal physical behavior, fabrication of such structures also presents a great challenge to this area, owing to the subtle and sensitive interactions among neighboring layers. Here we show by molecular dynamics simulations that narrow blue phosphorene nanoribbons can be encapsulated into carbon nanotubes driven by van der Waals interactions and form one-dimensional heterostructures. It shows that by varying carbon nanotube diameters and nanoribbon width, the nanoribbons can either retain their original straight structures or twist into tubular structures. Wrapping phases are also observed for large-sized blue phosphorus. It is found that the underlying mechanism originates from the competition between van der Waals energy and bending energy induced by tube curvature. A phase diagram of the resultant 1D structure is thus obtained based on a simple analysis of energetics. The results are expected to stimulate further experimental efforts in fabricating one-dimensional van der Waals heterostructues with desired functionality.

Creatures with longer bodies in nature like snakes and eels moving in water commonly generate a large swaying of their bodies or tails, with the purpose of producing significant frictions and collisions between body and fluid to provide the power of consecutive forward force. This swaying can be idealized by considering oscillations of a soft beam immersed in water when waves of vibration travel down at a constant speed. The present study employs a kind of large deformations induced by nonlinear vibrations of a soft pipe conveying fluid to design an underwater bio-inspired snake robot that consists of a rigid head and a soft tail. When the head is fixed, experiments show that a second mode vibration of the tail in water occurs as the internal flow velocity is beyond a critical value. Then the corresponding theoretical model based on the absolute nodal coordinate formulation (ANCF) is established to describe nonlinear vibrations of the tail. As the head is free, the theoretical modeling is combined with the computational fluid dynamics (CFD) analysis to construct a fluid-structure interaction (FSI) simulation model. The swimming speed and swaying shape of the snake robot are obtained through the FSI simulation model. They are in good agreement with experimental results. Most importantly, it is demonstrated that the propulsion speed can be improved by 21% for the robot with vibrations of the tail compared with that without oscillations in the pure jet mode. This research provides a new thought to design driving devices by using nonlinear flow-induced vibrations.

The flexomagnetic effect involves the coupling of inhomogeneous mechanical and magnetic excitations to generate exotic spin orders. The intrinsic edge stress associated with lifting of periodic degeneracy at surfaces or edges in nanostructures facilitates the flexocoupling effects. Here, we combine first-principles calculation and Maximum Information Coefficient (MIC) statistics to quantitatively reveal the impact of bending on the geometries, spin ordering state, and exchange interactions in chromium triiodide (CrI3) nanoribbons. Our results reveal a divergent magnetic ground state at small curvature but a plumb line shape noncollinear state at large curvatures. More importantly, our work establishes a gradient dependence of the exchange coupling on the locally asymmetric bending angles of the Cr-I-Cr hinge, governed by the coupling of the t2g and eg states of Cr. The superexchange gradient accompanied with the bending-induced inhomogeneous deformation sheds light on the evolution of magnetic ordering associated with asymmetric coordinating systems for sensors and spintronics.

This study presents a numerical model for the thermal-elastohydrodynamic lubrication of heterogeneous materials in impact motion, in which a rigid ball bounces on a starved non-Newtonian oil-covered plane surface of an elastic semi-infinite heterogeneous solid with inhomogeneous inclusions. The impact–rebound process and the microscopic response of the subsurface inhomogeneous inclusions are investigated. The inclusions are homogenized according to Eshelby’s equivalent inclusion method. The Elrod algorithm is adopted to determine the lubrication starvation based on the solutions of pressure and film thickness, while the lubricant velocity and shear rate of the non-Newtonian lubricant are derived by using the separation flow method. The dynamic response of the cases subjected to constant impact mass, momentum, and energy is discussed to reveal the influence of the initial drop height on the impact–rebound process. The results imply that the inclusion disturbs the subsurface stress field and affects the dynamic response of the contact system when the surface pressure is high. The impact energy is the decisive factor for the stress peak, maximum hydrodynamic force, and restitution coefficient, while the dynamic response during the early approaching process is controlled by the drop height. Nanyang Technological University National Research Foundation (NRF) Published version This research work was conducted in the SMRT-NTU Smart Urban Rail Corporate Laboratory with funding support from the National Research Foundation (NRF), Singapore, SMRT, Singapore and Nanyang Technological University, Singapore. Q.B. also acknowledges the support from National Natural Science Foundation of China, China (Grant No. 51905051).

A new topology of ensemble fuzzy-radial basis function neural networks (EFRBFNN) based on a multi-feature fusion strategy is proposed to recognize and classify a pattern of reliable on-site partial discharge (PD). This study is concerned with the design of an ensemble neural networks based on fuzzy rules and the enhancement of its recognition capability with the aid of preprocessing technologies and multi-feature fusion strategy. The key points are summarized as follows: (1) principal component analysis (PCA) and linear discriminant analysis (LDA) algorithm are utilized to reduce the dimensionality of input space as well as extracting features. (2) statistical characteristics (SC) are obtained as the complementary characteristics of the PD. (3) the proposed network architecture consists of two-branch radial basis function neural networks (RBFNN) based on fuzzy rules, which can effectively reflect the distribution of the input data. Two types of RBFNN are designed which are based on hard c-means (HCM) and fuzzy c-means (FCM) clustering respectively. To fuse the learned features by PCA and LDA, we design a multi-feature fusion strategy that not only adjusts the contribution of different features to the networks but also enhances the recognition ability for PD. The performance of the proposed networks is evaluated using PD data obtained from four types of defects in the laboratory environment, and noise that might occur in power grids is also concerned. The experimental results of the proposed EFRBFNN show the satisfied recognition requirement for PD datasets.

The dynamic deformation of thin-film stacked structures in the bond pad of microelectronic devices usually occurs when the contact load rapidly increases during the wire-bonding process. This work developed dynamic strain rate model for analyzing the dynamic response of thin-film stacked structures at varying loading rates. Dynamic strain rate tests were performed by maintaining the ratio of instantaneous load rate to load. The indentation stress–strain curves at different testing protocols were plotted. We found that the deformation decreased as the prescribed rate increased because of the rate-dependent characteristics of the thin Cu film.

Diabetic cardiomyopathy (DCM) is a cardiovascular complication that tends to occur in patients with diabetes, obesity, or insulin resistance, with a higher late mortality rate. Sustained hyperglycemia, increased free fatty acids, or insulin resistance induces metabolic disorders in cardiac tissues and cells, leading to myocardial fibrosis, left ventricular hypertrophy, diastolic and/or systolic dysfunction, and finally develop into congestive heart failure. The close connection between all signaling pathways and the complex pathogenesis of DCM cause difficulties in finding effective targets for the treatment of DCM. It reported that hydrogen sulfide (H2S) could regulate cell energy substrate metabolism, reduce insulin resistance, protect cardiomyocytes, and improve myocardial function by acting on related key proteins such as differentiation cluster 36 (CD36) and glucose transporter 4 (GLUT4). In this article, the relative mechanisms of H2S in alleviating metabolic disorders of DCM were reviewed, and how H2S can better prevent and treat DCM in clinical practice will be discussed.

Development of flexible, low cost, highly sensitive, and large-area compliance pressure sensors that can detect human physiological signals have become one of the vital component units for wearable electronics. Herein, a highly flexible and stretchable carbon black-porous polydimethylsiloxane-based pressure sensor has been successfully fabricated using a simple and effective fabrication technique with a sacrificial power template method. The pore size on the performance of pressure sensor is systematically investigated using KCl, NaCl, and sugar as powder templates to produce the porous PDMS. Notably, the KCl-templated PDMS pressure sensor exhibits a maximum pressure sensitivity (1.07 kPa−1 in 0–2 kPa), which is significantly higher than that of the NaCl-templated PDMS pressure sensor (0.86 kPa−1 in 0–2.5 kPa) and the sugar-templated PDMS pressure sensor (0.40 kPa−1 in 0–2.8 kPa). The KCl-templated PDMS pressure sensor has other advantages as well, including a fast response time of − 16 ms, a wide sensing range of 0–11,700 Pa, a low detection limit of − 2 mN, and a good reproducibility for over 3000 cycles. With these advantages, it is demonstrated that the pressure sensor can monitor minute mechanical events and human physiological signals, such as weak airflow blown, swallowing motion, finger touch, and pronunciation. Therefore, this new pressure sensor, which exhibit excellent comprehensive performance, will have wide application prospects in health monitoring and wearable devices.

The structural characteristics of the surfaces of sharkskin have great influence on their aerodynamic performance. It has been proved that the sharkskin’s ribbed structure can improve the aerodynamic performance of the parts up to 10%. At present, the main processing methods for this structure are laser, rolling, etc., which have low efficiency and poor surface integrity. Belt grinding is widely used in the surface grinding and polishing. It plays an important role in improving the surface integrity and can realize the micro-structure machining at the same time. To achieve drag reduction, based on the characteristics of drag reduction of Bionic-Ribbed Structures (BRS), different BRS (V, trapezoid and wave) on a blade were processed and studied. First, this paper introduces the theory of drag reduction induced by BRS and processing methods of different BRS on a blade by belt grinding, and carried out the verification of the belt-grinding methods. Then, different BRS models were established on the blade with different tip angles, and the aerodynamic performance was analyzed through simulation. It was found that the low-velocity layer near the BRS decreased when tip angle increased. Its wall shear stress also increased and tip angle of 45o had the best performance regardless of which BRS was. Some suggestions were given for belt grinding. The velocity along height from valley of BRS and velocity streamline was demonstrated. Secondary vortex was observed. Velocity gradient and vortex were the main reasons for the difference of wall shear stress.

Existing research has mostly focused on the salutary impact of nostalgia on nostalgia-related products (e.g., childhood products, classic brands). The current research examines whether this effect can extend to nostalgia-unrelated products: new products. We demonstrate that nostalgia fosters social support, which in turn encourages consumers to adopt new products, and this effect is weakened when individuals have independent self-construal. Three studies provide support for these predictions. Study 1 revealed that nostalgia increases new product adoption. Study 2 demonstrated that this positive effect of nostalgia on new product adoption is mediated by social support. Study 3 showed that this salutary effect occurs only when consumers’ interdependent self is activated. The marketing implications of these findings are discussed.

This work focuses on training difficulty and high computational cost caused by high-resolution input image when car plate character recognition based on support vector machine is applied. The use of singular value decomposition technology is proposed with improved optimal threshold analysis strategy to select retained features. The original data set is mapped in the low-dimensional feature space and the model is trained. The same test set is used to evaluate the models trained under different feature dimensions, and the optimal feature dimension is determined to 32 dimensional features. Results showed that the algorithm can accurately classify and detect license plate characters. The proposed model achieves 99.69% accuracy of the original data set, demonstrates excellent advantages, and remarkably simplifies the model design when only 96 dimensional features are used compared with traditional linear and convolutional neural network classifiers. New methods reduce the algorithm run time by 200%, and the number of parameter storage required by the algorithm to 25%. Hence, the proposed method can significantly improve the license plate recognition system usage in resource-constrained embedded devices.

A thermomechanical model is developed to predict the temperature, degree of crystallization, residual stress, and strain in the selective laser sintering process for polymeric powder. Especially, a transient heat transfer model is used to calculate the temperature evolution. An elastic–viscoplastic model is developed to describe the temperature- and time-dependent stress–strain behavior of polymeric materials with crystallization-induced strain being included. A crystallization model is used to predict the relative crystallization degree during the cooling process. The sintering process and cooling process of polyamide 12 are simulated using the developed model. The melt pool depth and the deformation of the printed parts are validated by the experimental results. The evolutions of the temperature, relative degree of crystallization, strain, and stress are evaluated. The effects of the cooling rate on the strain and stress evolutions are discussed.

Sarcoplasmic/endoplasmic reticulum calcium ATPase SERCA2 mediates calcium re-uptake from the cytosol into sarcoplasmic reticulum, and its dysfunction is a hallmark of heart failure. Multiple factors have been identified to modulate SERCA2 activity, however, its regulation is still not fully understood. Here we identify a Ral-GTPase activating protein RalGAPα1 as a critical regulator of SERCA2 in cardiomyocytes through its downstream target RalA. RalGAPα1 is induced by pressure overload, and its deficiency causes cardiac dysfunction and exacerbates pressure overload-induced heart failure. Mechanistically, RalGAPα1 regulates SERCA2 through direct interaction and its target RalA. Deletion of RalGAPα1 decreases SERCA2 activity and prolongs calcium re-uptake into sarcoplasmic reticulum. GDP-bound RalA, but not GTP-bound RalA, binds to SERCA2 and activates the pump for sarcoplasmic reticulum calcium re-uptake. Overexpression of a GDP-bound RalAS28N mutant in the heart preserves cardiac function in a mouse model of heart failure. Our findings have therapeutic implications for treatment of heart failure.

Insulin signals through its receptor to recruit insulin receptor substrates (IRS) and phosphatidylinositol 3-kinase (PI3K) to the plasma membrane for production of phosphatidylinositol-3,4,5-trisphosphate (PIP3) from phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2], which consequently activates protein kinase B (PKB). How insulin signals transduce from the plasma membrane into the cytoplasm is not clearly understood. Here we show that liquid–liquid phase separation (LLPS) plays a critical role in spatiotemporal control of insulin signaling through regulating multiple components including IRS1. Both protein concentration and insulin stimulation can drive the formation of intracellular IRS1 condensates through LLPS. Components including PI(4,5)P2, p85-PI3K and PDK1 are constitutively present in IRS1 condensates whereas production of PIP3 and recruitment of PKB in them are induced by insulin. Thus, IRS1 condensates function as intracellular signal hubs to mediate insulin signaling, whose formation is impaired in insulin resistant cells. Collectively, these data reveal an important function of LLPS in spatiotemporal control of insulin signaling.

In several previous studies, it was reported that a supported pipe with small geometric imperfections would lose stability when the internal flow velocity became sufficiently high. Recently, however, it has become clear that this conclusion may be at best incomplete. A reevaluation of the problem is undertaken here by essentially considering the flow-induced static deformation of a pipe. With the aid of the absolute nodal coordinate formulation (ANCF) and the extended Lagrange equations for dynamical systems containing non-material volumes, the nonlinear governing equations of a pipe with three different geometric imperfections are introduced and formulated. Based on extensive numerical calculations, the static equilibrium configuration, the stability, and the nonlinear dynamics of the considered pipe system are determined and analyzed. The results show that for a supported pipe with the geometric imperfection of a half sinusoidal wave, the dynamical system could not lose stability even if the flow velocity reaches an extremely high value of 40. However, for a supported pipe with the geometric imperfection of one or one and a half sinusoidal waves, the first-mode buckling instability would take place at high flow velocity. Moreover, based on a further parametric analysis, the effects of the amplitude of the geometric imperfection and the aspect ratio of the pipe on the static deformation, the critical flow velocity for buckling instability, and the nonlinear responses of the supported pipes with geometric imperfections are analyzed.

Direct chemical oxidation and pure adsorption could not effectively remove p-Arsanilic acid (p-ASA) and the released inorganic arsenic. Herein, one novel biochar supported MnFe2O4 (MFB) was synthesized and adopted for p-ASA degradation and synchronous adsorption of the generated inorganic arsenic. The MFB/persulfate (PS) system could remain effective under a wide pH range (3.0–9.0), and the released arsenic could be removed simultaneously by MFB. Mechanism investigation revealed that the functional groups of MFB (i.e. O–C=O and C=O), Fe and Mn oxides on MFB all contributed to PS activation. O2·− and 1O2 were the main reactive oxygen species (ROS) responsible for p-ASA degradation, and 1O2 was the predominant ROS. Besides, the MFB possessed superior reusability. Therefore, it is expected to develop a potential method for organic arsenic contaminants removal via an oxidation-adsorption process, and the results could also shed light on the better understanding of the PS activation mechanisms. Graphical Abstract

Phage-derived therapies are promising treatments in the fight against bacterial diseases as an alternative strategy nowadays. Species of Aeromonas veronii is an important pathogen causing freshwater fish diseases, the findings on genomic sequences of their bacteriophages are limited. In this work, a lytic bacteriophage capable of specifically infecting A. veronii strain AEv1810 was characterized at the gene level and was designated as pAEv1810. Transmission electron microscopic observation revealed that pAEv1810 belongs to the family of Myoviridae. The genome of phage pAEv1810 consists of 235,066 bp with 38.4% G + C content. Twenty-three of 249 putative proteins encoded by this phage have known functions, and four tRNA genes were found in phage genome. Phylogenetic analyses of RNA polymerase and Terminase large subunit revealed that phage pAEv1810 is closing to those phages classified to the genus Petsuvirus.

Background Even though the modulatory effects of Magnisum (Mg) and its alloys on bone-healing cells have been widely investigated during the last two decades, relatively limited attention has been paid on their inflammation-modulatory properties. Understanding the activation process of macrophages in response to the dynamic degradation process of Mg as well as the relationship between macrophage phenotypes and their osteogenic potential is critical for the design and development of advanced Mg-based or Mg-incorporated biomaterials. Methods In this work, a Ti-0.625 Mg (wt.%) alloy fabricated by mechanical alloying (MA) and subsequent spark plasma sintering (SPS) was employed as a material model to explore the inflammatory response and osteogenic performance in vitro and in vivo by taking pure Ti as the control. The data analysis was performed following Student’s t-test. Results The results revealed that the macrophages grown on the Ti-0.625 Mg alloy underwent sequential activation of M1 and M2 phenotypes during a culture period of 5 days. The initially increased environmental pH (~ 8.03) was responsible for the activation of M1 macrophages, while accumulated Mg2+ within cells contributed to the lateral M2 phenotype activation. Both M1 and M2 macrophages promoted osteoblast-like SaOS-2 cell maturation. In vivo experiment further showed the better anti-inflammatory response, regenerative potentiality and thinner fibrous tissue layer for the Ti-0.625 Mg alloy than pure Ti. Conclusion The results highlighted the roles of Mg degradation in the Ti-0.625 Mg alloy on the sequential activation of macrophage phenotypes and the importance of modulating M1-to-M2 transition in macrophage phenotypes for the design and development of inflammation-modulatory biomaterials.

The West Kunlun region forms the northern margin of the Tibetan Plateau, and sedimentation in this region contributed to plateau formation and its northwards expansion, as well as the development of central Asian aridification. However, the stratigraphic dating framework in this region has been ambiguous, hampering the understanding of both tectonic and environmental evolution. Here, palynological analysis was performed on the Xialafudie Formation in the West Kunlun region. Together with the palynological assemblage and megafossils found in the study section, as well as regional stratigraphic comparison, we conclude that the Xialafudie Formation was deposited during the Pliocene, and not Early Cretaceous as previously reported. The palynological assemblage of the section is mainly composed of drought-tolerant herbs and shrubs, and the percentage of conifers and broadleaved trees is very low, indicating that a dry and cold environment prevailed in the West Kunlun region during the Pliocene. Comprehensively analysed palynological data from the Tarim Basin and its surroundings show that aridification intensified in this part of central Asia during the Pliocene, as a result of long-term global cooling and regional tectonism.

There has been an unsettling rise in the intensity and frequency of natural disasters due to climate change and anthropogenic activities. Artificial intelligence (AI) models have shown remarkable success and superiority to handle huge and nonlinear data owing to their higher accuracy and efficiency, making them perfect tools for disaster monitoring and management. Accordingly, natural disaster management (NDM) with the usage of AI models has received increasing attention in recent years, but there has been no systematic review so far. This paper presents a systematic review on how AI models are applied in different NDM stages based on 278 studies retrieved from Elsevier Science, Springer LINK and Web of Science. The review: (1) enables increased visibility into various disaster types in different NDM stages from the methodological and content perspective, (2) obtains many general results including the practicality and gaps of extant studies and (3) provides several recommendations to develop innovative AI models and improve the quality of modeling. Overall, a comprehensive assessment and evaluation for the reviewed studies are performed, which tracked all stages of NDM research with the applications of AI models.

For the Guanshui Road Station tunnel project of Guiyang Metro Line 2, the wind pavilion group was moved out of the main tunnel to reduce the number of openings in the main tunnel, and the wind pavilion group was excavated in a triangular configuration at the entrance of the main tunnel. Based on the finite element software ABAQUS, a three-dimensional model is established to study the influence of different triangular-distribution tunnels excavation schemes on the surface settlement and tunnel stability. The objective of this study is to reveal the change rules of surface settlement, deformation and force in the support structures and the surrounding rock and identify the best excavation scheme for this tunnel configuration. Results show that to control the surface settlement and the deformation of the support structures, the optimal excavation sequence involves excavating the upper fresh air exhaust tunnel before the lower running tunnel. To control the stress of the support structures, the optimal excavation involves excavating the lower running tunnel before the upper fresh air exhaust tunnel. In this project, the most reasonable excavation sequence of the tunnel is from top to bottom. The most reasonable thickness of tunnel penetration is 5 m.

Reasonable hydrophobic anode is deemed to be a promising electrode for photoelectrocatalytic degradation of wastewater. In this study, the C3N4-modified Ti/PbO2 electrode with tunable hydrophobic characteristics is fabricated by a facile electrodeposition process. It is found that the introduction of C3N4 into the PbO2 films changed the morphology, surface hydrophilicity, and hydrophobicity of the electrode, which promotes the photoelectrochemical active areas, generating efficiency of hydroxyl radicals. In addition, introducing C3N4 into PbO2 coating can enhance oxygen evolution potential and carrier density of PbO2. Photoelectrocatalytic degradation experiments show that the addition of C3N4 can further improve the catalytic performance of PbO2 and there exists a significant photoelectric synergism in photoelectrocatalytic process. These results demonstrate that the combination of reasonable surface hydrophobic characteristics and photoelectrocatalytic is a prospective approach for wastewater treatment.

We report the fabrication of P-doped α-Fe2O3 nanorod/BiVO4 heterojunction photoelectrode for photoelectrochemical (PEC) water splitting. The heterojunction photoelectrode is fabricated by combining methods of hydrothermal deposition, wet impregnation and metal organic decomposition. The structure and PEC activity of the photoelectrode are systemically studied. This heterojunction photoelectrode exhibits a surprising photocurrent density of 1.17 mA/cm2 at 0.8 V vs. Ag/AgCl, which is approximately 3.55 times higher than that of the pristine α-Fe2O3. The photoconversion efficiency is 9.58 times higher than α-Fe2O3 and the onset potential has an obvious negative shift of 450 mV compared to the α-Fe2O3 for the heterojunction photoelectrode. The significant enhancement of PEC water splitting performance is attributed to the heterojunction structure and the synergistic effects of P-doping, which contributes to expediting electron and hole transfer and reducing carriers recombination. This novel design may provide an efficient way to developing efficient heterojunction photoelectrodes for practical PEC application.

Traditional photosensitizers are predominantly based on various types of polypyrrole macrocycles, which are generally used in homogeneous and/or suspension states. In the present study, a new non-polypyrrole-based photosensitizer (LW-PBI) was developed via the introduction of a nonplanar spirofluorene into a derivative of perylene bisimides (PBI) containing two long-alkyl chains. Photophysical studies demonstrated that the compound shows good solubility in common organic solvents, great photochemical stability, and high absorption efficiency in the visible light region. Due to containing of two energetically matchable, independent fluorescent units, the compound as prepared displays strong tendency to form non-fluorescent charge-separated states under light irradiation in polar solvents. Based on the merits, LW-PBI was examined for its catalytic property in the photo-production of singlet oxygen in film state. Luckily, the compound is an effective photosensitizer in the generation of the active oxygen species as verified by its unique reaction with uric acid (UA). Further studies revealed that the effective photo-production of singlet oxygen can be also realized via the utilization of a tiny and low-price LED lamp as a light source and as a film support. Detailed studies on the application of the conceptual device as a medical instrument for photodynamic therapy (PDT) are in progress.

The main aim of the present study is to explore the nonlinear vibrations of a fluid-conveying cantilevered pipe under an axial base excitation, by considering both two-dimensional (2-D) and three-dimensional (3-D) responses of the pipe. For this purpose, the extended Hamilton’s principle is applied to derive the 3-D nonlinear governing equations of the pipe with an axial base excitation. The resulting partial differential equations are then discretized by employing a Galerkin method. The Floquet theory is adopted to determine the stability regions of the pipe system. A linear analysis shows that the internal flow velocity, excitation amplitude and excitation frequency have great influences on the stability regions of the pipe system, indicating that both subharmonic and combination resonances can occur. The planar and non-planar nonlinear responses of the pipe are calculated by using a fourth-order Runge–Kutta integration algorithm. These nonlinear responses of the pipe are displayed in the form of bifurcation diagrams, phase-plane plots, power spectrum diagrams, Poincare maps, oscillating shapes and oscillation trajectories of the pipe tip. Our numerical results demonstrate that, for a pipe conveying fluid with a subcritical flow velocity, the presence of an axial excitation is able to generate resonant responses, while for a pipe conveying fluid with a supercritical flow velocity, the axial excitation can even make the pipe stable in some specific cases. Furthermore, it is interesting that a self-excited non-planar periodic oscillation can evolve to a planar quasi-periodic or periodic oscillation by adding the axial excitation. In such a fluid–structure interaction system, however, it is shown that a self-excited planar motion cannot be shifted to a non-planar one by adding the axial excitation, at least for the system parameters considered in this work.