Ultrasensitive Fluorescence Lifetime Tuning in Patterned Polymer Composite Nanofibers with Plasmonic Nanostructures for Multiplexing.

Regulating fluorescence lifetime of lanthanide nanocomposites is highly desired for optical multiplexing applications, for instance, security printing, anticounterfeiting, and data storage. Herein, sensitive fluorescence lifetime tuning in nanocomposite fibers is reported which are composed of silica-coated gold nanorods assembled in Eu-polystyrene nanofibers. The prepared nanofibers possess unique properties of tunable fluorescence lifetime and distinct textured patterns together with superior flexibility and superhydrophobicity. In a single 612 nm emission channel, over ten different populations of fluorescence lifetime from the range of 322-551 µs are harvested. Thanks to the tunable fluorescence lifetime and different textured patterns, a security pattern to demonstrate optical multiplexing applications is designed. The security pattern hides the real information of "69" in a noticeable scene that shows fake information "8" under UV radiation or "13" by only watching their pattern structures.

Giant spontaneous exchange bias obtained by tuning magnetic compensation in samarium ferrite single crystals.

Spontaneous exchange bias (SEB) under zero field cooling (ZFC) has recently attracted lots of attention due to its underlying physics and potential applications. Here we report the giant SEB (GSEB) of SmFeO3 single crystals by tuning magnetic compensation by temperature, which is rather convenient. A SEB field of up to 1 T at 3.9 K after ZFC (-1.4 T at 3.9 K after field cooling) was obtained. The SEB shows reciprocal relationship with remnant magnetization.

Piezoluminescence from ferroelectric Ca3Ti2O7:Pr3+ long-persistent phosphor.

A variety of up-and-coming applications of piezoluminescence in artificial skins, structural health diagnosis, and mechano-driven lightings and displays recently have triggered an intense research effort to design and develop new piezoluminescent materials. In this work, we deduced and verified an efficient piezoluminescence in ferroelectric Ca3Ti2O7:Pr3+ long-persistent phosphor, in view of three fundamental elements forming piezoluminescence - piezoelectricity, luminescent centers and carrier traps. Under the stimulation of mechanical actions including compression and friction, Ca3Ti2O7:Pr3+ shows an intense red emission from 1D2-3H4 transition of Pr3+. On the basis of investigations on structural and optical characteristics especially photoluminescence, persistent luminescence and thermoluminescence, we finally proposed a possible piezoluminescent mechanism in Ca3Ti2O7:Pr3+. Our research is expected to expand the horizon of existing piezoluminescent materials, accelerating the development and application of new materials.

Multicolor Tuning in Room-Temperature Self-Activated Ca2 Nb2 O7 Submicroplates by Lanthanide Doping.

Self-activated phosphors are capable of generating optical emissions from the internal ion groups of host lattice before externally introducing luminescent ions. However, numerous self-activated phosphors only show luminescence at low temperature due to the thermally activated energy migration among ion groups at room temperature, severely confining their application conditions. In this letter, we propose a strategy to converting the low-temperature luminescence to a room-temperature one through changing the synthesis conditions to induce structural distortions and thus to limit energy migration. Room-temperature self-activated luminescence of Ca2 Nb2 O7 was accordingly achieved in submicroplates synthesized using the sol-gel method. By further coupling the blue broadband emission from Ca2 Nb2 O7 submicroplates with the characteristic luminescence of Ln3+ (Pr3+ , Sm3+ , and Dy3+ ) dopants, multicolor emissions were successively tuned through adjusting the concentration of Ln3+ . Our results are expected to expand the scope of designing room-temperature self-activated phosphors and tuning multicolor emission.

Electrical conduction mechanism of an individual polypyrrole nanowire at low temperatures.

Conducting polypyrrole (PPY) nanowires doped with p-toluene sulfonamide (PTSA) were synthesized by a template-free self-assembly method. Electrical transport characteristics, i.e. current-voltage (I-V) behavior, of an individual PPY/PTSA nanowire have been explored in a wide temperature range from 300 down to 40 K. The fitting results of I-V curves indicated that the electrical conduction mechanism can be explained by the space-charge-limited current (SCLC) theory from 300 down to 100 K. In this temperature range, traps play an important role for this non-crystalline system. The corresponding trap energy and trap concentration have also been calculated based on the SCLC theory. Interestingly, there is no trap at 160 K, different from other temperatures. The obtained carrier mobility for the polymer nanowires is 0.964 cm(2) V(-1) s(-1) on the basis of trap free SCLC theory. In the temperature range of 80-40 K, little current can flow through the nanowire especially at lower voltages, however, the current follows the equation I ∞ (V/Vt-1)(ζ) at higher bias, which could be attributed to Coulomb blockade effect. Additionally, the differential conductance dI/dV curves also show some clear Coulomb oscillations.

Dynamic multicolor emissions of multimodal phosphors by Mn2+ trace doping in self-activated CaGa4O7.

The manipulation of excitation modes and resultant emission colors in luminescent materials holds pivotal importance for encrypting information in anti-counterfeiting applications. Despite considerable achievements in multimodal and multicolor luminescent materials, existing options generally suffer from static monocolor emission under fixed external stimulation, rendering them vulnerability to replication. Achieving dynamic multimodal luminescence within a single material presents a promising yet challenging solution. Here, we report the development of a phosphor exhibiting dynamic multicolor photoluminescence (PL) and photo-thermo-mechanically responsive multimodal emissions through the incorporation of trace Mn2+ ions into a self-activated CaGa4O7 host. The resulting phosphor offers adjustable emission-color changing rates, controllable via re-excitation intervals and photoexcitation powers. Additionally, it demonstrates temperature-induced color reversal and anti-thermal-quenched emission, alongside reproducible elastic mechanoluminescence (ML) characterized by high mechanical durability. Theoretical calculations elucidate electron transfer pathways dominated by intrinsic interstitial defects and vacancies for dynamic multicolor emission. Mn2+ dopants serve a dual role in stabilizing nearby defects and introducing additional defect levels, enabling flexible multi-responsive luminescence. This developed phosphor facilitates evolutionary color/pattern displays in both temporal and spatial dimensions using readily available tools, offering significant promise for dynamic anticounterfeiting displays and multimode sensing applications.

Elastico-mechanoluminescence in CaZr(PO4)2:Eu2+ with multiple trap levels.

We report on a novel elastico-mechanoluminescence (EML) phosphor of CaZr(PO4)2:Eu2+ for simultaneous luminescent sensing and imaging to mechanical load by the light-emitting of Eu2+ ions. The EML properties of CaZr(PO4)2:Eu2+ show an intense luminance (above 15 mcd m(-2)), a low load threshold (below 5 N), a broad measurement range for the dynamic load (up to 2000 N), and an accurate linear relationship of EML intensity against the applied load. The excellent EML characteristics are considered to originate from the piezoelectric crystal structure and the multiple trap levels with appropriate depths. An EML mechanism based on the electrons as the main charge carriers is proposed.

An intense elastico-mechanoluminescence material CaZnOS:Mn2+ for sensing and imaging multiple mechanical stresses.

The elastico-mechanoluminescence (EML) properties of CaZnOS:Mn2+ are investigated. The CaZnOS:Mn2+/epoxy resin composite can simultaneously "feel" (sense) and "see" (image) various types of mechanical stress over a wide energy and frequency range (ultrasonic vibration, impact, friction and compression) as an intense red emission (610 nm) from Mn2+ ions. Further, the accurate linear relation between emission intensity and different stress parameters (intensity, energy and deformation rate) are confirmed. The EML mechanism is explained using a piezoelectrically induced trapped carrier excitation mode. All the results imply that CaZnOS:Mn2+ has potential as a stress probe to sense and image multiple mechanical stresses and decipher the stress intensity distribution.

Senescent skeletal cells cross-talk with synovial cells plays a key role in the pathogenesis of osteoarthritis.

Osteoarthritis (OA) has been recognized as an age-related degenerative disease commonly seen in the elderly that affects the whole "organ" including cartilage, subchondral bone, synovium, and muscles. An increasing number of studies have suggested that the accumulation of senescent cells triggering by various stresses in the local joint contributes to the pathogenesis of age-related diseases including OA. In this review, we mainly focus on the role of the senescent skeletal cells (chondrocytes, osteoblasts, osteoclasts, osteocyte, and muscle cells) in initiating the development and progression of OA alone or through cross-talk with the macrophages/synovial cells. Accordingly, we summarize the current OA-targeted therapies based on the abovementioned theory, e.g., by eliminating senescent skeletal cells and/or inhibiting the senescence-associated secretory phenotype (SASP) that drives senescence. Furthermore, the existing animal models for the study of OA from the perspective of senescence are highlighted to fill the gap between basic research and clinical applications. Overall, in this review, we systematically assess the current understanding of cellular senescence in OA, which in turn might shed light on the stratified OA treatments.

Short-Term Non-Decaying Mechanoluminescence in Li2MgGeO4:Mn2.

Trap-controlled mechanoluminescent (ML) materials characterized by reproducible mechanoluminescence (ML) after irradiation recharging have shown attractive prospects in applications including stress distribution visualization, stress-driven light sources, and anti-counterfeiting. However, these materials generally suffer from the difficulty of achieving non-decaying ML when subjected to continuous mechanical stimulation. Herein, we develop a trap-controlled reproducible ML material, Li2MgGeO4:Mn2+, and report its short-term non-decaying ML behavior. Investigation of trap properties suggests that the unique non-decaying ML behavior should arise from the deep traps existing in Li2MgGeO4:Mn2+, which provide electron replenishment for shallow traps that release small numbers of electrons during short-term cyclic friction. Our results are expected to provide a reference for the ultimate achievement of long-term non-decaying ML in such materials.

Detection of circulating genetically abnormal cells in peripheral blood for early diagnosis of non-small cell lung cancer.

BACKGROUND: Circulating genetically abnormal cells (CACs) with specific chromosome variations have been confirmed to be present in non-small cell lung cancer (NSCLC). However, the diagnostic performance of CAC detection remains unclear. This study aimed to evaluate the potential clinical application of the CAC test for the early diagnosis of NSCLC. METHODS: In this prospective study, a total of 339 participants (261 lung cancer patients and 78 healthy volunteers) were enrolled. An antigen-independent fluorescence in situ hybridization was used to enumerate the number of CACs in peripheral blood. RESULTS: Patients with early-stage NSCLC were found to have a significantly higher number of CACs than those of healthy participants (1.34 vs. 0.19; P < 0.001). The CAC test displayed an area under the receiver operating characteristic (ROC) curve of 0.76139 for discriminating stage I NSCLC from healthy participants with 67.2% sensitivity and 80.8% specificity, respectively. Compared with serum tumor markers, the sensitivity of CAC assays for distinguishing early-stage NSCLC was higher (67.2% vs. 48.7%, P < 0.001), especially in NSCLC patients with small nodules (65.4% vs. 36.5%, P = 0.003) and ground-glass nodules (pure GGNs: 66.7% vs. 40.9%, P = 0.003; mixed GGNs: 73.0% vs. 43.2%, P < 0.001). CONCLUSIONS: CAC detection in early stage NSCLC was feasible. Our study showed that CACs could be used as a promising noninvasive biomarker for the early diagnosis of NSCLC. KEY POINTS: What this study adds: This study aimed to evaluate the potential clinical application of the CAC test for the early diagnosis of NSCLC. Significant findings of the study: CAC detection in early stage NSCLC was feasible. Our study showed that CACs could be used as a promising noninvasive biomarker for the early diagnosis of NSCLC.

Expression response of chalcone synthase gene to inducing conditions and its effect on flavonoids accumulation in two medicinal species of Anoectochilus.

Anoectochilus roxburghii and Anoectochilus formasanus are the major species of genus Anoectochilus used in traditional Chinese medicine for their abundant content of flavonoids and some other medicinal constituents. In recent years, their wild resources are gradually exhausted due to over-collection and ecological deterioration. Artificial cultivation and tissue culture are employed to increase production. In this study, the open reading frame, promoter and genomic sequences of the chalcone synthase (CHS) gene were cloned from these two species according to their transcriptome information, and used for expression analysis in response to the induction of phenylalanine, ultraviolet light and NaCl, and its effect investigation on accumulation of flavonoids. The results showed that the expression of the CHS genes was upregulated in response to these inductions and resulted in increasing accumulation of total flavonoids. However, the increased flavonoids induced by phenylalanine and ultraviolet light were mainly allocated into the anthocyanidin branch of flavonoids biosynthesis. Not only did it improved the medicinal value, but might have inhibitory effect on plant growth because of the increased malondialdehyde accumulation. Under the induction of appropriate concentration of NaCl, the medicinal constituents of flavonoids were increased without inhibition to plant growth.

[Effects of Sb3+ on the luminescent properties of Tb3+ doped silicate glass].

The Sb(3+)-doped silicate glasses, Tb(3+)-doped silicate glasses, and Sb3+ and Tb3+ co-doped silicate glasses were synthesized by high-temperature melting method, and their spectral properties were analyzed. The effects of Sb2O3 added as a fining agent on the luminescent properties of Tb(3+)-doped silicate glasses were studied with excitation spectra, emission spectra and decay time. The results show that there is energy transfer from Sb3+ ions to Tb3+ ions in the Sb3+ and Tb3+ co-doped silicate glasses under UV excitation, but the energy transfer efficiency between them is quite low. The energy transfer takes place between the 3P1 energy level of Sb3+ ions and the 5D3 energy level of Tb3+ ions in the Sb3+ and Tb3+ co-doped silicate glasses, and the way of the energy transfer from Sb3+ ions to Tb3+ ions is nonradiative energy resonance transfer. Meanwhile, introducing Sb2O3 used as a fining agent will reduce the excitation intensity of Tb3+ ions in the silicate glasses in the overlap excitation region of both Sb3+ ions and Tb3+ ions, which corresponds to the region from 200 to 350 nm. The reduction in the excitation intensity of Tb3+ ions caused by introducing Sb3+ ions is so evident that it can not be compensated by the energy transfer from Sb3+ ions to Tb3+ ions. Therefore, the negative effects of Sb3+ ions on the luminescent properties of Tb3+ ions in silicate glasses should be measured when Sb2 O3 is planned to be used as a fining agent in Tb(3+)-doped silicate glasses.

Achieving Thermo-Mechano-Opto-Responsive Bitemporal Colorful Luminescence via Multiplexing of Dual Lanthanides in Piezoelectric Particles and its Multidimensional Anticounterfeiting.

Optical characteristics of luminescent materials, including emission color (wavelength), lifetime, and excitation mode, play crucial roles in data communication and information security. Conventional luminescent materials generally display unicolor, unitemporal, and unimodal (occasionally bimodal) emission, resulting in low-level readout and decoding. The development of multicolor, multitemporal, and multimodal luminescence in a single material has long been considered to be a significant challenge. In this study, for the first time, the superior integration of colorful (red-orange-yellow-green), bitemporal (fluorescent and delayed), and four-modal (thermo-/mechano-motivated and upconverted/downshifted) emissions in a particular piezoelectric particle via optical multiplexing of dual-lanthanide dopants is demonstrated. The as-prepared versatile NaNbO3 :Pr3+ ,Er3+ luminescent microparticles shown are particularly suitable for embedding into polymer films to achieve waterproof, flexible/wearable and highly stretchable features, and synchronously to provide multidimensional codes that can be visually read-out using simple and commonly available tools (including the LED of a smartphone, pen writing, cooling-heating stimuli, and ultraviolet/near-infrared lamps). These findings offer unique insight for designing highly integrated stimuli-responsive luminophors and smart devices toward a wide variety of applications, particularly advanced anticounterfeiting technology.

AC Electroluminescent Processes in Pr3+-Activated (Ba0.4Ca0.6)TiO3 Diphase Polycrystals.

We investigated the properties of alternating current (AC)-driven electroluminescence from (Ba0.4Ca0.6)TiO3:Pr3+ diphase polycrystal-based device. The results of crystal phases and micrographs, and the symmetrical dual emissions in one AC cycle, indicate the spontaneous formation of a dielectric/phosphor/dielectric sandwich microstructure in (Ba0.4Ca0.6)TiO3:Pr3+. The electroluminescent device emits a red light of 617 nm, which is attributed to the ¹D2-³H4 transition of Pr3+ in the phosphor phase. At a fixed AC frequency, the intensity of electroluminescence exhibits a steep enhancement when applying an increased driving electric field that is beyond a threshold. In a fixed driving electric field, the intensity of electroluminescence shows a rapid rise at low frequencies, but reaches saturation at high frequencies. Based on a double-injection model, we discussed systematically the electroluminescent processes in a whole cycle of AC electric field, which matched well with the experimental data. Our investigation is expected to expand our understanding of such a diphase electroluminescent device, thereby promoting their applications in lighting and displays.

Colorful Hydrophobic Poly(Vinyl Butyral)/Cationic Dye Fibrous Membranes via a Colored Solution Electrospinning Process.

Colorful nanofibrous membranes have attracted much attention for their visual varieties and various functionalities. In this article, a colored solution electrospinning process was used to fabricate colorful hydrophobic poly(vinyl butyral) (PVB)/cationic dye nanofibrous membranes (NFMs) successfully. The color and morphology of these as-spun nanofibrous membranes have been analyzed by colorimetry, spectroscopy, and scanning electron microscopy (SEM). It is shown that the as-spun colorful PVB-based membranes exhibit excellent level-dyeing property and color stability. Furthermore, the doping of cationic dye and the increase of dye concentration can decrease the diameter of the as-spun colored fibers, which results in better level-dyeing property and higher water contact angle more than 140°. The stained PVB fibrous membranes with excellent level-dyeing property and hydrophobicity are promising in some applications such as textiles, wallpapers, and anticorrosive coating/painting.

Electrospun anisotropic architectures and porous structures for tissue engineering.

In order to design scaffolds for tissue engineering with proper architectures, organization and properties, a variety of materials and technologies are being developed. In addition to being biocompatible both in their bulk and degraded forms, scaffolds should not only possess appropriate mechanical properties to provide a suitable stress environment, but also be porous and permeable to permit the ingress of cells and nutrients. In this review, we aim to summarize recent advances in electrospun anisotropic architectures such as aligned fibrous arrays, fibrous yarns and bundles, fibrous tubular structures, and porous structures, as well as their formation mechanisms and mechanical properties. In particular, the potential applications of these structure-controlled fibrous constructs in neural regeneration, vascular grafts, cardiac tissue, skeletal muscle regeneration, tendon repair, and cornea repair are presented. Moreover, the current challenges and future opportunities for the use of these scaffolds in research and clinical practice are proposed.

Electrical transport properties of an isolated CdS microrope composed of twisted nanowires.

CdS is one of the important II-VI group semiconductors. In this paper, the electrical transport behavior of an individual CdS microrope composed of twisted nanowires is studied. It is found that the current-voltage (I-V) characteristics show two distinct power law regions from 360 down to 60 K. Space-charge-limited current (SCLC) theory is used to explain these temperature- and electric-field-dependent I-V curves. The I-V data can be well fitted by this theory above 100 K, and the corresponding carrier mobility, trap energy, and trap concentration are also obtained. However, the I-V data exhibit some features of the Coulomb blockade effect below 80 K.

Self-powered electrospinning apparatus based on a hand-operated Wimshurst generator.

A conventional electrospinning setup cannot work without a plug (electricity supply). In this article, we report a self-powered electrospinning setup based on a hand-operated Wimshurst generator. The new device has better applicability and portability than a typical conventional electrospinning setup because it is lightweight and can work without an external power supply. Experimental parameters of the apparatus such as the minimum number of handle turns to generate enough energy to spin, rotation speed of the handle and electrospinning distance were investigated. Different polymers such as polystyrene (PS), poly(vinylidene fluoride) (PVDF), polycaprolactone (PCL) and polylactic acid (PLA) were electrospun into ultrathin fibers successfully by this apparatus. The stability, reliability, and repeatability of the new apparatus demonstrate that it can be used as not only a demonstrator for an electrospinning process, but also a beneficial complement to conventional electrospinning especially where or when without a power supply, and may be used in wound healing and rapid hemostasis, etc.

[Progress of the SUPERMAN epigenetic mutation in Arabidopsis].

The SUPERMAN gene in Arabidopsis has its epigenetic mutants (the clark kent alleles,clk). The phenotype of clk and its genotype and methylated patterns and the epi-mutation mechanisms of SUPERMAN were summarized in the review. Heritable but unstable sup epi-alleles are associated with nearly identical patterns of excess cytosine methylation within the SUP gene and a decreased level of SUP RNA. The methylation of cytosine at CpG and CPXPG is controlled by METHYLTRANSFERASE1(MET1) and CHROMOMETHYLASE3 (CMT3) which is regulated by KRYPTONITE gene, respectively.