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Impaired angiogenesis is one of the predominant reasons for non-healing diabetic wounds. Herein, a nanofiber/hydrogel core–shell scaffold with three-dimensional (3D) multilayer patterned structure (3D-PT-P/GM) was introduced for promoting diabetic wound healing with improved angiogenesis. The results showed that the 3D-PT-P/GM scaffolds possessed multilayered structure with interlayer spacing of about 15–80 μm, and the hexagonal micropatterned structures were uniformly distributed on the surface of each layer. The nanofibers in the scaffold exhibited distinct core–shell structures with Gelatin methacryloyl (GelMA) hydrogel as the shell and Poly (d, l-lactic acid) (PDLLA) as the core. The results showed that the porosity, water retention time and water vapor permeability of the 3D-PT-P/GM scaffolds increased to 1.6 times, 21 times, and 1.9 times than that of the two-dimensional (2D) PDLLA nanofibrous scaffolds, respectively. The in vitro studies showed that the 3D-PT-P/GM scaffolds could significantly promote cell adhesion, proliferation, infiltration and migration throughout the scaffolds, and the expression of cellular communication protein-related genes, as well as angiogenesis-related genes in the same group, was remarkably upregulated. The in vivo results further demonstrated that the 3D-PT-P/GM scaffolds could not only effectively absorb exudate and provide a moist environment for the wound sites, but also significantly promote the formation of a 3D network of capillaries. As a result, the healing of diabetic wounds was accelerated with enhanced angiogenesis, granulation tissue formation, and collagen deposition. These results indicate that nanofiber/hydrogel core–shell scaffolds with 3D multilayer patterned structures could provide a new strategy for facilitating chronic wound healing. Graphical Abstract

To investigate the effect of azimuthal anisotropy on frequency-domain marine controlled-source electromagnetic (CSEM) responses, an adaptive edge-based finite-element (FE) modeling algorithm is presented in this letter. The 3-D algorithm is capable of dealing with generally anisotropic conductive media. It is implemented on unstructured tetrahedral grids, which allow for complex model geometries. The accuracy of the FE solution is controlled through adaptive mesh refinement, which is performed iteratively until the solution converges to the desired accuracy tolerance. The algorithm is validated against the quasi-analytic solutions for a 1-D layered model with anisotropy. We then simulate the marine CSEM responses over a set of 3-D anisotropic models and illustrate that the azimuthal anisotropy has a considerable influence on both the inline and broadside marine CSEM responses but to different extents.

In this study, a micropatterned scaffold with surface-loaded spherical bioactive glasses was successfully fabricated by the electrospinning technique and polydopamine (PDA) coating method for diabetic wound healing. The micro- to nanoscaled hierarchical structure and PDA coating could mimic the structure and function of the native extracellular matrix (ECM), and the scaffold could sustainably release the Si and Ca ions. The

Insufficient angiogenesis in the chronic wound of the diabetic is one of the most important causes that making the wound unable to heal itself. In this work, a cobalt-based metal–organic framework (ZIF-67) was introduced as a carrier for loading a pro-angiogenic small molecular drug (dimethyloxalylglycine, DMOG). To achieve a long-term angiogenic therapy on the diabetic wound beds, a dual cooperative controllable release system has been designed by incorporating the drug-loaded ZIF-67 nanoparticles into the micro-patterned PLLA/Gelatin nanofibrous scaffolds. The results showed that DMOG was incorporated into ZIF-67 with a high loading ratio (359.12 mg/g), and the drug-loaded ZIF-67 nanoparticles were well embedded in the circular patterned scaffold. Notably, the DMOG as well as Co ions could continuously release from the scaffold for more than 15 days. The in vitro studies showed that the released Co ions and DMOG from the micropatterned nanofibrous scaffolds could synergistically promote the proliferation, migration and tube formation of the human umbilical vein endothelial cells (HUVECs) by inducing a hypoxia response and upregulating the expression of angiogenesis-related genes such as HIF-1α, VEGF and e-NOS. Furthermore, the in vivo results demonstrated that the composite scaffolds could significantly enhance angiogenesis, collagen deposition and eliminate inflammation in the diabetes wounds. These results indicate that the cobalt-based metal–organic framework as a dual cooperative controllable release system provides a new strategy for enhancing angiogenesis and promoting diabetic wound healing.

Chronic wounds are one of the most serious complications of diabetes mellitus. Even though utilizing nitric oxide (NO) as a gas medicine to repair diabetic wounds presents a promising strategy, controlling the NO release behavior in the affected area, which is vital for NO-based therapy, still remains a significant challenge. In this work, a copper-based metal-organic framework, namely, HKUST-1, has been introduced as a NO-loading vehicle, and a NO sustained release system with the core-shell structure has been designed through the electrospinning method. The results show that the NO is quantificationally and stably loaded in the HKUST-1 particles, and the NO-loaded HKUST-1 particles are well incorporated into the core layer of the coaxial nanofiber. Therefore, NO can be controllably released with an average release rate of 1.74 nmol L-1 h-1 for more than 14 days. Moreover, the additional copper ions released from the degradable HKUST-1 play a synergistic role with NO to promote endothelial cell growth and significantly improve the angiogenesis, collagen deposition as well as anti-inflammatory property in the wound bed, which eventually accelerate the diabetic wound healing. These results suggest that such a copper-based metal-organic framework material as a controllable NO-releasing vehicle is a highly efficient therapy for diabetic wounds.

Objective: To develop an integrative model with clinical, pathological, and radiomic characteristics to predict the status of microsatellite instability (MSI) in rectal carcinoma (RC). Methods: A cohort of 788 RCs with 97 high MSI status (MSI-H) and 691 microsatellite stable status (MSS) were enrolled. The clinical and pathological characteristics were recorded. The radiomic features were calculated after segmentation of volume of interests and then patients were divided into the training set and validation set with a random proportion of 7:3. The logistic models of simple clinical characteristics (LM-Clin), pathological characteristics (LM-Patho), and radiomic features (LM-Radio) were constructed to distinguish MSI-H from MSS. The relevant radiomic score was calculated. Finally, a integrative nomogram (LM-Nomo) including significant clinical, pathological characteristics, and radiomics was developed. The area under receiver operator curve (AUC) was calculated to evaluate the efficacy of prediction. Results: The AUC of simple LM-Clin including variables of CEA and hypertension and LM-Patho including characteristics of gross type and lymph node metastasis ratio (LNR) was 0.584 (95%CI, 0.549-0.619) and 0.585 (95%CI, 0.550-0.619), which was lower than that of LM-Radio including 12 radiomic features with AUC of 0.737 (95%CI, 0.675-0.799). The LM-Nomo contained CEA, hypertension, LNR, and radiomic score, and the AUC was 0.757 (95%CI, 0.726-0.787). Conclusion: The AUCs of LM-Clin and LM-Patho were disappointing and lower than that of LM-Radio. The LM-Nomo demonstrated the best performance in predicting MSI-H status.

Macrophages can phagocytose sperm, especially damaged spermatozoa, in the female genital tract. The semenogelin I-derived peptide SgI-52 in seminal plasma exhibits seminal plasma motility inhibitor (SPMI) activity and can inhibit sperm motility. This raises the question of the role played by SPMIs in macrophage-mediated phagocytosis of sperm. We speculated that SgI-52 promotes sperm clearance by macrophages. Therefore, we investigated the phagocytosis of sperm in different states using this peptide.SgI-52 was fluorescently labeled, and its binding site for sperm was observed. The ability of macrophages to phagocytose sperm was observed using fluorescence confocal microscopy. Spermatozoa from different sources were co-cultured with SgI-52 in BWW medium for 4 and 22 h to compare the differences in their phagocytosis by macrophages. Sperm motility, induced acrosome reaction, mitochondrial membrane potential, and ATP content were examined after incubation with SgI-52.SgI-52 could bind to spermatozoa in different states, mainly to the tail, and then spread to the acrosome. This effect was more pronounced in demembranated spermatozoa. SgI-52 promoted phagocytosis of spermatozoa by macrophages, decreased the mitochondrial membrane potential, and increased the average ATP content of spermatozoa (P 0.05).We found for the first time that SgI-52 can bind to spermatozoa in different states and promote their phagocytosis by macrophages. Therefore, we speculate that SgI-52 is involved in the screening of sperm in the female reproductive tract and has potential value in improving assisted reproductive technology.

In order to analyze the thermal environment and its influence on workers’ thermal adaptation, a field study was conducted in a rubber factory during winter. Indoor and outdoor environmental parameters were measured and subjective questionnaire surveys were collected. The study was conducted from November to January the next year. During the survey, indoor temperature was in the range of 12.6 to 21.7°C and indoor air velocity ranged from 0.15 to 0.3 m/s. The clothing insulation during heating period was between 0.85-0.9 clo, while it was between 1.21-1.33 clo during pre-heating period. The estimated metabolic rate was around 2-2.2 met. Analysis showed that the thermal sensation vote (TSV) was higher than that predicted by PMV. The neutral temperature difference between TSV and PMV was 4.8°C. The thermal comfort and thermal adaptation of workers in winter were systematically analyzed and a thermal adaptive model was proposed. Basis on the adaptive model, the comfort temperature range of workers was suggested.

Very recently, perovskite based microdisk lasers have attracted considerable research attention. However, most of the researches are focused on the lasing spectra in bottom-up synthesized microdisks with regular shapes. The directionality, which is also essential for practical applications, has not been explored. Here we demonstrate unidirectional lasing emissions from perovskite microdisks for the first time. We synthesized the rectangle-shaped microdisks connected with straight waveguides and studied the lasing characteristics, where unidirectional emissions along the waveguides have been observed. Numerical calculations reveal that the unidirectional emissions are formed by the breaking of total internal reflections at the joints between waveguides and microdisks. Since waveguides are compatible with other photonic elements, we believe that our finding will be essential for the applications of perovskite microdisks in integrated photonic circuits and networks.

Lead halide perovskite micro-devices such as microplates and microwires have shown great potential in microlasers, especially in the “green gap” wavelength region of conventional semiconductors. However, the synthesized perovskite lasers are usually randomly distributed on the substrate, making their laser emissions hard to be collected and utilized. Here we demonstrate a simple way to efficiently couple perovskite microlasers into conventional single mode fibers. By attaching a perovskite microwire onto a tapered fiber via micromanipulation, we found that the emissions along the single mode fiber are more than an order of magnitude larger than the collected emission with a 40× objective lens (NA = 0.6). The detailed estimation shows that the experimentally measured collection efficiency at one end of the tapered fiber can be around 13–20%, which is good enough for practical applications. Our numerical calculations show that the collection is mainly induced by the diffraction at the end of the microwire instead of the evanescent coupling and the total coefficient at the two ends can be further improved by optimizing the tapered fiber and microwire. As the tapered fiber is drawn from a commercial single-mode fiber, this research clearly shows the potential of perovskite devices to be integrated with conventional fiber systems.

Solution-processed lead halide perovskites have shown good applicability in both solar cells and microlasers. Very recently, the nonlinear properties of perovskites have attracted considerable research attention. Second harmonic generation and two-photon absorption have been successfully demonstrated. However, perovskite devices based on these nonlinear properties, such as micro- and nanolasers have thus far not been fabricated. Here we demonstrate two-photon pumped microlasers from CH3NH3PbBr3 perovskite microwires. These CH3NH3PbBr3 perovskite microwires are synthesized through a one-step solution precipitation method and dispersed on a glass substrate. Under optical excitation at 800 nm, two-photon pumped lasing action with periodic peaks is successfully observed at around 546 nm. The obtained quality (Q) factors of the two-photon pumped microlasers are around 682, and the corresponding thresholds are about 674 µJ cm-2. Both the Q factors and thresholds are comparable to conventional whispering-gallery modes in two-dimensional polygon microplates. This work is the first demonstration of two-photon pumped microlasers in CH3NH3PbBr3 perovskite microwires. We believe our finding will significantly expand the application of perovskites in low-cost nonlinear optical devices, such as optical limiters, optical switches, and biomedical imaging devices.

Folds and faults are the most common types of basic structures in geological formations. Marine controlled-source electromagnetic (CSEM) data are strongly affected by folds, faults and other complex irregular geological structures in subsea geo-environments because of their electrical anisotropy and the bathymetry generated by these types of structures. In this work, we investigate the effects of two typical geological structures, folds and faults, on marine CSEM responses by using an adaptive finite-element modeling approach. The adoption of unstructured tetrahedral grids in our code easily allows the inclusion of complex model geometries so that natural environments can be mapped into the model realistically. For the fold models, we investigate the impacts of anticlines, synclines and mixed anticline-syncline-type structures; numerical results indicate that both anticlines and synclines can produce considerable negative electromagnetic anomalies, which may be neutralized to a certain extent by the positive electromagnetic anomalies of a highly resistive target reservoir. The response curve of a syncline displays a “W” shape whose central part consisting of rising positive anomalies may be mistaken as the response of a highly resistive reservoir when interpreting CSEM data. Furthermore, the negative anomalies caused by the anticlines/synclines increase with the increasing inclination of their limbs. For the fault models, we investigate the effects of horsts and grabens on marine CSEM responses and results show that the responses of horsts/grabens can be large enough to mask the target reservoir's response. We conclude that folds and faults clearly have to be taken into account to avoid the misinterpretation of marine CSEM data.

As the “kidneys of the Earth”, wetlands play important roles as biodiversity reservoirs, in water purification, and in flood control. In this study, 2 lytic cold-active bacteriophages, named VW-6S and VW-6B, infecting Pseudomonas fluorescens W-6 cells from the Napahai plateau wetland in China were isolated and characterized. Electron microscopy showed that both VW-6S and VW-6B had an icosahedral head (66.7 and 61.1 nm, respectively) and a long tail (8.3 nm width × 233.3 nm length and 11.1 nm width × 166.7 nm length, respectively). The bacteriophages VW-6S and VW-6B were classified as Siphoviridae and had an approximate genome size of 30–40 kb. The latent and burst periods of VW-6S were 60 and 30 min, whereas those of VW-6B were 30 and 30 min, respectively. The optimal pH values for the bacteriophages VW-6S and VW-6B were 8.0 and 10.0, respectively, and their activity decreased rapidly at temperatures higher than 60 °C. These cold-active bacteriophages provide good materials for further study of cold-adaptation mechanisms and interaction with the host P. fluorescens.

Light confinement and amplification in micro- and nanofibers have been intensively studied, and a number of applications have been developed. However, typical micro- and nanofibers are usually free-standing or positioned on a substrate with lower refractive index to ensure the light confinement and guiding mode. Here we numerically and experimentally demonstrate the possibility of confining light within a microfiber on a high refractive index substrate. In contrast to the strong leakage to the substrate, we found that the radiation loss was dependent on the radius of the microfiber and the refractive index contrast. Consequently, quasi-guiding modes could be formed and the light could propagate and be amplified in such systems. By fabricating a tapered silica fiber and dye-doped polymer fiber and placing them on sapphire substrates, the light propagation, amplification, and consequent laser behaviors have been experimentally studied to verify the quasi-guiding modes in a microfiber on a higher index subst...

In order to design sampled grating comb filter, the effect of sampled fiber grating’s parameters on reflective spectrum was analyzed. Sampled grating comb filter can be applied in the intensive optical communication system. Sampled grating reflective spectrum was simulated by changing the parameters. Four kinds of sampled grating optical comb filter were designed. In order to optimize the function of sampled grating comb filter, a filtering analysis and denoising method by using EMD were proposed. This method divides intrinsic mode function into two modes by EMD. One of mode was that signal components mode play dominant role, the other mode was that inoise component mode plays dominant role. The mode of noise component play dominant role was removed. It can denoise reflective spectrum through restructuring signal. The smooth reflective spectrum and delay spectrum can be got after denoising. So that the peak value of sampled grating can be judged accurately.

Here we numerically and experimentally demonstrate the conversion of normally incident light into the guiding modes of distributed Bragg reflector (DBRs) mirror. By fabricating a gold grating onto a 7.5 pairs TiO2/SiO2 DBR mirror, a series of asymmetrical resonances have been formed at the bandgap range of the DBR mirror. The detailed numerical calculations show that these Fano resonances are attributed to the coupling of incident waves into guiding modes of the DBR mirror. Compared with the other resonances, this coupling mechanism can be simply realized and it has also been revealed to be quite robust to the environmental changes, making the conversion between propagating waves and guiding waves to be practically interesting for many applications.

The control of photoluminescence and absorption of lead halide perovskites plays a key role in their applications in micro- and nano-sized light emission devices and photodetectors. To date, the wavelength controls of lead halide perovskite microlasers are mostly realized by changing the halide mixture in solution. Herein, we report the postsynthetic and selective control of the optical properties of lead halide perovskites with conventional semiconductor technology. By selectively exposing a CH3NH3PbBr3 microstructure with chlorine in inductively coupled plasma, we find that the wavelengths of absorption, photoluminescence, and laser emissions of exposed structures are blue-shifted around 50 nm. Most importantly, the device characteristics such as the photoluminescence intensities and laser thresholds are well maintained during the reaction process. We believe our finding will significantly boost the practical applications of lead halide perovskite based optoelectronics.

Semiconductor microwires have attracted much current attention due to their excellent geometric uniformities, inherent optical gain, relatively high refractive index, making them potential candidates for microscale electronic and optoelectronic building blocks, especially as the next frontier in miniaturization of semiconductor lasers. Recently, organic-lead halide perovskite semiconductors (CH 3 NH 3 PbX 3 with X = Cl, Br, I), with high optical absorption coefficient, optimal direct band gap, and long electron/hole diffusion lengths, good optical properties and long electron hole diffusion length, which ensure adequate gain and efficient optical feedback, have become a research hotspot to achieve semiconductor lasers. Up to now, both Fabry-Perot (FP) lasing and Whispering Gallery Mode (WGM) lasing have been observed in perovskite micro-cavities, such as microwires, hexagonal microplates and square microdisks. However, the lasing mechanism is fixed once the perovskite microcavity is synthesized. Here the transition between FP lasing and WGM lasing is demonstrated in perovskite microwires and moreover, the transition is reversible without any damage to the samples. The CH 3 NH 3 PbBr 3 perovskite microwires are synthesized with one-step solution based self-assembled method and the typical lengths are tens of microns with an aspect ratio about 1 in the transverse plane. When perovskite microwire on glass substrate is pumped uniformly above threshold, FP lasing action can be observed which oscillates between the two end facets along the microwire axial direction. By repositioning the microwire on a perovskite block with one end suspending in the air or placing a perovskite block on one end of the microwire via micromanipulation, the FP lasing mode can be suppressed. In such case, single mode lasing can be excited when the suspending end of the microwire is pumped. After transferring the microwire to glass substrate again, FP lasing can be observed when pumped uniformly. Numerical simulations show that the perovskite block induces huge leaky loss to the microwire, which suppresses the FP lasing mode. As the lasing modes corresponds to the high quality (Q) modes, WGM modes exhibit larger Q factor than the FP modes in the transverse plane. Therefore, the single mode lasing originates from WGM mode in the transverse plane when the FP modes are suppressed. By introducing perovskite blocks, transition between FP lasing in the microwire axial direction and WGM lasing in the transverse plane can be achieved without any damage to the sample. The proposed mechanism provides a simple and flexible way to tailor the perovskite lasing actions, exhibiting potential applications in integrated photonic circuits and light sources.

The lytic cold-active bacteriophage VSW-3, belonging to the Podoviridae family and infecting the host Pseudomonas fluorescens SW-3, was isolated from the Napahai plateau wetland in China. With the development of sequencing technology, the study of Pseudomonas genomic diversity has increased; however, knowledge of cold-active phages infecting Pseudomonas is limited. The newly sequenced phage VSW-3 was classified based on virion morphology by transmission electron microscope. Sequence analysis revealed that the genome size was 40,556 bp with an overall GC content of 57.54 % and 46 open reading frames. The genome was organized into several modules containing genes for packaging, structural proteins, replication/transcription, and phage lysis. The sequence contained 45 potential promoters, 3 transcription terminators, and yet no tRNAs. This is the first report of cold-active Pseudomonas fluorescens bacteriophage genome sequencing.

The role of excitons on the amplifications of lead halide perovskites has been explored. Unlike the photoluminescence, the intensity of amplified spontaneous emission is partially suppressed at low temperature. The detailed analysis and experiments show that the inhibition is attributed to the existence of exciton and a quantitative model has been built to explain the experimental observations.

In summary, rod-shaped bacterial cells and Pseudomonas spp. dominated the bacterial community in the Napahai plateau wetland. Based on our TEM results, bacteriophages with larger capsids (60–140 nm) and Siphoviridae members were dominant. We were able to isolate a batch of cultured cold-active bacteriophages and their host bacterial strains, which should provide opportunities for further qualitative or quantitative analysis of bacteriophage function in wetland ecology. Specifically, these new isolates can help clarify bacteriophage coldadaptation mechanisms, structure, and assembly, as well as improve our understanding of phage-host co-evolution and interactions.