Precisely Tailoring Upconversion Dynamics via Energy Migration in Core-Shell Nanostructures.

Upconversion emission dynamics have long been believed to be determined by the activator and its interaction with neighboring sensitizers. Herein this assumption is, however, shown to be invalid for nanostructures. We demonstrate that excitation energy migration greatly affects upconversion emission dynamics. "Dopant ions' spatial separation" nanostructures are designed as model systems and the intimate link between the random nature of energy migration and upconversion emission time behavior is unraveled by theoretical modelling and confirmed spectroscopically. Based on this new fundamental insight, we have successfully realized fine control of upconversion emission time behavior (either rise or decay process) by tuning the energy migration paths in various specifically designed nanostructures. This result is significant for applications of this type of materials in super resolution spectroscopy, high-density data storage, anti-counterfeiting, and biological imaging.

Sharp bend in two-dimensional optical waveguide based on gradient refractive index structure.

In this work, we propose the design of a sharp bend in a two-dimensional optical waveguide which has super-ellipse curve boundaries and a gradient refractive index structure in its core. Numerical simulations are presented to show the efficient light propagation in the waveguide bend, as well as the efficient light coupling between the proposed waveguide bend and a straight waveguide, for TE0 and TM0 modes. The proposed design strategy is also useful for designing other compact optical and photonic components.

Plasmonic Ag@oxide nanoprisms for enhanced performance of organic solar cells.

Localized surface plasmon resonance (LSPR), light scattering, and lowering the series resistance of noble metal nanoparticles (NPs) provide positive effect on the performance of photovoltaic device. However, the exciton recombination on the noble metal NPs accompanying above influences will deteriorate the performance of device. In this report, surface-modified Ag@oxide (TiO2 or SiO2 ) nanoprisms with 1-2 nm shell thickness are developed. The thin film composed of P3HT/Ag@oxides and P3HT:PCBM/Ag@oxides is investigated by absorption, photoluminescence (PL), and transient absorption spectroscopy. The results show a significant absorption, PL enhancement, and long-lived photogenerated polaron in the P3HT/Ag@TiO2 film, indicating the increase of photogenerated exciton population by LSPR of Ag nanoprisms. In the case of P3HT/Ag nanoprisms, partial PL quench and relatively short-lived photogenerated polaron are observed. That indicates that the oxides layer can effectively avoid the exciton recombination. When the Ag@oxide nanoprisms are introduced into the active layer of P3HT:PCBM photovoltaic devices, about 31% of power conversion efficiency enhancement is obtained relative to the reference cell. All these results indicate that Ag@oxides can enhance the performance of the cell, at the same time the ultrathin oxide shell prevents from the exciton recombination.

Modeling and optimization of photonic crystal devices based on transformation optics method.

In this paper, we propose a method for designing Photonic Crystal (PhC) devices that consist of dielectric rods with varying size. In the proposed design method, PhC devices are modeled with the Transformation Optics (TO) approach, and then they are optimized using the gradient method. By applying the TO technique, the original device model is transformed into an equivalent model that consists of uniform and fixed-sized rods, with parameterized permittivity and permeability distributions. Therefore, mesh refinement around small rods can be avoided, and PhC devices can be simulated more efficiently. In addition, gradient of the optimization object function is calculated with the Adjoint-Variable Method (AVM), which is very efficient for optimizing devices subject to multiple design variables. The proposed method opens up a new avenue to design and optimize a variety of photonic devices for optical computing and information processing.

Critical-edge based tabu search algorithm for solving large-scale multi-vehicle Chinese postman problem.

The min-max multi-vehicle Chinese postman problem is an NP-hard problem, which is widely used in path planning problems based on road network graphs, such as urban road structure probing planning, urban road underground cavity detection planning, high-voltage line inspection planning, and so on. With the rapid increase in the number of nodes and connections of road network graph, the solution time and path equilibrium constraints pose new challenges to the problem solving. In this paper, we propose a critical-edge tabu search algorithm, CTA-kroutes, for solving the min-max multi-vehicle postman problem for large-scale road networks. First, the initial solution with balanced path lengths is obtained by segmenting the Eulerian paths; second, the critical edges are moved in the initial solution to construct the neighborhood solution, and the tabu search algorithm is used to find the optimal solution iteratively; and lastly, the solution optimization algorithm is used at the end of each iteration to de-duplicate and optimally reconstruct the current search result. Experiments show that the CTA-kroutes algorithm can effectively improve the equalization of multi-vehicle paths and its applicability to large-scale road networks.

Clinical characteristics, viral dynamics, and antibody response of monkeypox virus infections among men with and without HIV infection in Guangzhou, China.

Background: Monkeypox virus (MPXV) is spreading globally and nearly half of the infected people were human immunodeficiency virus (HIV) positive. Therefore, an in-depth understanding of the effects of HIV infection on the outcomes of MPXV infection is urgently needed. This study aimed to explore the clinical features, viral dynamics, and antibody response to MPXV infections in men who had sex with men (MSM) with and without HIV co-infection. Design or methods: MPXV-infected patients diagnosed by PCR were recruited in this study and were divided into MPXV and MPXV + HIV groups based on whether they were co-infected with HIV. Clinical data and samples were collected during of the hospital stay and follow up interviews. The symptoms and signs, laboratory examinations, viral shedding in various body fluids or swabs, antibody dynamics were tracked and compared between the two groups. Results: A total of 41 MPXV patients were recruited through June 2023 to September 2023 in Guangzhou. The MPXV group and MPXV + HIV group comprised 20 and 21 MSM, respectively. Patients in the two groups exhibited similar clinical characteristics except for pruritus and eschar, both were significantly fewer in MPXV + HIV group than in MPXV only group. Among the 355 clinical samples collected, MPXV DNA was detected in 100% of scabs, 97.4% of skin swabs, and 92.3% of exudate swabs from lesions, while the positive rate was 87.5% from oropharyngeal swabs, 59% from saliva, 51.3% from anal swabs, 50% from feces, 30.6% from urine samples, 37.5% of semen, and 28.2% from sera. Dynamics analysis revealed that viral DNA was undetectable in most patients 20 days after symptom onset. IgM and IgG antibodies to MPXV were detected in all patients with 3-5 days earlier in the MPXV group than in the MPXV + HIV group. Conclusion: This cohort analysis based on a large outbreak among MSM in Guangzhou indicated no obvious differences in clinical symptoms, viral DNA data, but antibody responses were 3-5 days later in mpox patients with HIV infection.

Future Green Technology: A Freezing Water Micro-Droplet as an Optical Switch Based on a Time-Domain Photonic Hook.

This paper pays attention to the broader interest of freezing water droplets in mesotronics, particularly to their use as a new all-optical device platform. Here, we show that a freezing mesoscale water droplet with a low Bond number can behave as fully biocompatible natural microlense to form a photonic hook for application in a tunable temperature-controlled optical switch. We first introduced and demonstrated the basic concepts of an optical switch without changes in the wavelength of illumination of a particle or any moving parts being involved. The principle of the operation of the switch is based on the temperature-induced phase change inside the water droplet's refractive index. The simulation results show that the optical isolation of switched channels for an optical switch with linear dimensions of about 15 λ3 based on a freezing water droplet can reach 10 dB in the process of temperature variation at a fixed wavelength. The use of freezing mesoscale droplets acting as a time-domain photonic hook generator open an intriguing route for optical switching in multifunctional green electronics tools for sensing, integrated optics and optical computers.

Time domain self-bending photonic hook beam based on freezing water droplet.

Tunable optical devices are of great interest as they offer adjustability to their functions. Temporal optics is a fast-evolving field, which may be useful both for revolutionizing basic research of time-dependent phenomena and for developing full optical devices. With increasing focus on ecological compatibility, bio-friendly alternatives are a key subject matter. Water in its various forms can open up new physical phenomena and unique applications in photonics and modern electronics. Water droplets freezing on cold surfaces are ubiquitous in nature. We propose and demonstrate the effectual generation of time domain self-bending photonic hook (time-PH) beams by using mesoscale freezing water droplet. The PH light bends near the shadow surface of the droplet into large curvature and angles superior to a conventional Airy beam. The key properties of the time-PH (length, curvature, beam waist) can be modified flexibly by changing the positions and curvature of the water-ice interface inside the droplet. Due to the modifying internal structure of freezing water droplets in real time, we showcase the dynamical curvature and trajectory control of the time-PH beams. Compared with the traditional methods, our phase-change- based materials (water and ice) of the mesoscale droplet have advantages of easy fabrication, natural materials, compact structure and low cost. Such PHs may have applications in many fields, including temporal optics and optical switching, microscopy, sensors, materials processing, nonlinear optics, biomedicine, and so on.

Basic chloroplast genome characterization of Phalaenopsis stobartiana (Orchidaceae) from China.

Phalaenopsis stobartiana Reichenbach f. 1877 is mainly distributed in Yunnan province of China and has a high ornamental and breeding value. Here, we reported the chloroplast genome of P. stobartiana. The length of the chloroplast genome was 145,900 bp, encoding 120 genes. The average GC content was 36.8%. Phylogenetic analysis revealed that P. stobartiana and P. wilsonii are closely related. The chloroplast genome could be used for further phylogenetic research, and provide molecular data for future genetic protection and breeding programs.

The complete chloroplast sequence of phalaenopsis malipoensis, a rare orchidaceae species in China.

Phalaenopsis malipoensis Z.J. Liu et S.C. Chen, 2005 is a valuable species of Orchidaceae with significant ornamental value. This study reports the first complete chloroplast genome of P.malipoensis was collected integrally and clarified further. The genome was 144,528 bp in length and comprised four regions, including a pair of inverted repeats each 24,710 bp, a large single-copy region of 83,475 bp, and a small single-copy region of 11,633 bp. The whole genome contained 125 genes, including 8 rRNAs, and 39 tRNAs. Phylogenetic analysis indicated that P. malipoensis was closely related to Phalaenopsis lobbii. The analysis of P. malipoensis chloroplast genome will provide significant data for the identification and further improvement of P. malipoensis.

The Melastoma dodecandrum genome and the evolution of Myrtales.

Melastomataceae has abundant morphological diversity with high economic and ornamental merit in Myrtales. The phylogenetic position of Myrtales is still contested. Here, we report the chromosome-level genome assembly of Melastoma dodecandrum in Melastomataceae. The assembled genome size is 299.81 Mb with a contig N50 value of 3.00 Mb. Genome evolution analysis indicated that M. dodecandrum, Eucalyptus grandis, and Punica granatum were clustered into a clade of Myrtales and formed a sister group with the ancestor of fabids and malvids. We found that M. dodecandrum experienced four whole-genome polyploidization events: the ancient event was shared with most eudicots, one event was shared with Myrtales, and the other two events were unique to M. dodecandrum. Moreover, we identified MADS-box genes and found that the AP1-like genes expanded, and AP3-like genes might have undergone subfunctionalization. The SUAR63-like genes and AG-like genes showed different expression patterns in stamens, which may be associated with heteranthery. In addition, we found that LAZY1-like genes were involved in the negative regulation of stem branching development, which may be related to its creeping features. Our study sheds new light on the evolution of Melastomataceae and Myrtales, which provides a comprehensive genetic resource for future research.

The complete chloroplast genome of Cymbidium hookerianum (Orchidaceae): genome structure and basic analysis.

Cymbidium hookerianum Rchb.f. is an ornamental orchid with large flowers and delicate aroma. Here, we reported the complete chloroplast genome sequence of C. hookerianum. The total chloroplast genome cycle was 155,447 bp. It displayed a typical structure including one large single-copy (LSC, 84,186 bp) region, one small single-copy (SSC, 17,839 bp) region, and two inverted repeat (IRs, 26,711 bp). 124 genes (78 CDSs, 38 tRNAs, 8 rRNAs) were encoded by the cp genome. The average GC content of this sequence was 36.8%. The phylogenetic analysis revealed C. hookerianum and C. changningense are sisters. The groundwork of chloroplast genome would provide available reference for molecular taxonomy and breeding.

Chloroplast characterizations of a Phalaenopsis native to China, Phalaenopsis mannii (Orchidaceae).

Phalaenopsis mannii, one of the native Phalaenopsis in China, is an important parent for breeding new varieties. However, its position has been unclear in Phalaenopsis. The obtained high-quality P. mannii chloroplast genome will provide useful information for phylogenetic and future breeding of Phalaenopsis. Herein, we reported a complete chloroplast genome of P. mannii from Yunnan, China. The sequencing data obtained from BGISEQ-500 platform were assembled. This sequence had a circular molecular length of 148,596 bp and contained a total of 127 genes with an average GC content of 36.7%. Phylogenetic analysis indicated that Phalaenopsis was monophyletic with strong support, in which the P.mannii was the sister-group of Phalaenopsis aphrodite subsp. formosas, Phalaenopsis 'TinyStar' and Phalaenopsis equestris.

Contralaterally controlled functional electrical stimulation improves wrist dorsiflexion and upper limb function in patients with early-phase stroke: A randomized controlled trial.

OBJECTIVES: To investigate the effectiveness of contralaterally controlled functional electrical stimulation (CCFES) on the recovery of active wrist dorsiflexion and upper limb function in patients with early-phase stroke (<15 days post-stroke). METHODS: Patients in the CCFES group were treated with routine rehabilitation combined with CCFES, while those in the conventional neuromuscular electrical stimulation (NMES) group were treated with routine rehabilitation combined with NMES. Time intervals from stroke onset to appearance of wrist dorsiflexion, and from onset of treatment to appearance of wrist dorsiflexion were recorded (in days). Functional assessments were also performed at baseline and endpoint. RESULTS: Nineteen out of 21 patients in the CCFES group and 12 out of 20 patients in the NMES group regained active wrist dorsiflexion during the treatment and follow-up period (90.5% vs 60%, p = 0.025). The mean time interval from onset of treatment to appearance of active wrist dorsiflexion was signifcantly shorter in the CCFES group than in the NMES group (p < 0.001). The CCFES group had signifcantly higher scores for upper extremity function (p = 0.001), strength of extensor carpi (p = 0.002), active ROM for wrist dorsiflexion (p = 0.003), activities of daily living score (p = 0.023) and ICF score (p < 0.001) than the NMES group at the endpoint. CONCLUSION: CCFES signifcantly shortened the time for regaining wrist dorsiflexion, and improved the upper extremity function and general health of patients with early-phase stroke. CCFES therefore has potential as a clinical intervention.

Deep Subwavelength-Scale Light Focusing and Confinement in Nanohole-Structured Mesoscale Dielectric Spheres.

One of the most captivating properties of dielectric mesoscale particles is their ability to form a sub-diffraction limited-field localization region, near their shadow surfaces. However, the transverse size of the field localization region of a dielectric mesoscale particle is usually larger than λ/3. In this present paper, for the first time, we present numerical simulations to demonstrate that the size of the electromagnetic field that forms in the localized region of the dielectric mesoscale sphere can be significantly reduced by introducing a nanohole structure at its shadow surface, which improves the spatial resolution up to λ/40 and beyond the solid immersion diffraction limit of λ/2n. The proposed nanohole-structured microparticles can be made from common natural optical materials, such as glass, and are important for advancing the particle-lens-based super-resolution technologies, including sub-diffraction imaging, interferometry, surface fabrication, enhanced Raman scattering, nanoparticles synthesis, optical tweezer, etc.

Optical vacuum cleaner by optomechanical manipulation of nanoparticles using nanostructured mesoscale dielectric cuboid.

Here, we propose the concept of an "optical vacuum cleaner" for optomechanical manipulation of nanoparticles. We utilize a dielectric cuboid to generate an optical gradient force exerted on the nanoparticles for particle's hovering and trapping. We show that the permittivity contrast between the particle and the nanohole leads to the deep subwavelength light confinement and enhancement at the opening of the nanohole located at the shadow surface of the particle. The proposed "optical vacuum cleaner" can be utilized in optomechanical manipulations on particles such as noble metal nanoparticles adsorbed on surfaces or controlling the particles taking part in cellular uptake.

Strong microwave absorption of hydrogenated wide bandgap semiconductor nanoparticles.

Electromagnetic interactions in the microelectronvolt (µeV) or microwave region have numerous important applications in both civil and military fields, such as electronic communications, signal protection, and antireflective coatings on airplanes against microwave detection. Traditionally, nonmagnetic wide-bandgap metal oxide semiconductors lack these µeV electronic transitions and applications. Here, we demonstrate that these metal oxides can be fabricated as good microwave absorbers using a 2D electron gas plasma resonance at the disorder/order interface generated by a hydrogenation process. Using ZnO and TiO2 nanoparticles as examples, we show that large absorption with reflection loss values as large as -49.0 dB (99.99999%) is obtained in the microwave region. The frequency of absorption can be tuned with the particle size and hydrogenation condition. These results may pave the way for new applications for wide bandgap semiconductors, especially in the µeV regime.

Stable Ag@oxides nanoplates for surface-enhanced Raman spectroscopy of amino acids.

Surface enhancement Raman scattering (SERS) is a powerful technique for detecting low-concentration analytes (chemicals and biochemicals). Herein, a high-performance SERS biosensing system has been created by using highly stable Ag@oxides nanoplates as enhancers. The Ag nanoplates were stabilized by coating a uniform ultrathin layer of oxides (SiO2 or TiO2) on the Ag surface through a simple sol-gel route. The thin oxide layer allows the plasmonic property of the original Ag nanoplates to be retained while preventing their contact with external etchants. The oxides provide an excellent platform for binding all kinds of molecules that contain a COOH group in addition to a SH group. We demonstrate that Ag@oxides have high performance with respect to the typical SERS molecule 4-ATP, which contains a typical SH group. Ag@oxides also can be directly employed for the SERS detection of amino acids. The highly stable Ag@oxides nanoplates are believed to hold great promise for fabricating a wide range of biosensors for the detection of many other biomolecules and may also find many interesting opportunities in the fields of biological labeling and imaging.

The current situation and countermeasures for conservation of ancient and famous trees in Laoshan, Qingdao, China / A situação atual e contramedidas para a conservação de árvores antigas e famosas em Laoshan, Qingdao, China

ABSTRACT: This study aimed to examined the characteristics of ancient and famous trees in Laoshan District, Qingdao City, Shandong Province, China, including species composition, number of individuals, origin, distribution, and age structure, to highlight the values of inheriting history and culture, improving urban environment, protecting regional biodiversity, promoting tourism economy and so on. The analyses was made through field surveys and quantitative analyses of statistical data and relevant literature, The main issues in their conservation are investigated and priority conservation measures are proposed. Results showed that there are 290 ancient and famous trees, comprising 42 species, 34 genera, and 26 families. These included four types of ancient and famous trees with different origins, namely religious trees planted by Buddhists, naturally preserved wild trees, trees with agricultural backgrounds for providing food or used as offerings, and exotic trees introduced from other places. There are relatively more local species and comparatively more elder trees. Ancient and famous trees are distributed in large numbers in Mountain Lao Scenic Area and many of them fall into temperate genera. Currently, ancient and famous tree conservation in Laoshan District is challenging because of issues such as habitat deterioration, severe effects of natural hazards, pests and diseases, weakening physiological function, and inadequate management. Based on all these analyses, countermeasures are proposed, which include regularly inspecting ancient and famous trees, restoring their habitats, reinforcing pest and disease controls, promoting studies on conservation technologies, improving management practices, increasing grants, and reforming the ownership system of ancient and famous trees.

RESUMO: No presente estudo foram examinadas as características, incluindo espécies, número, origem, distribuição e estrutura etária de árvores antigas e famosas no distrito de Laoshan, cidade de Qingdao, província de Shandong, China. Para tal empregou-se um levantamento de campo e análises quantitativas de dados estatísticos e literatura relevante disponível. As principais questões relativas à sua conservação foram investigadas e medidas de conservação prioritárias são propostas. Os resultados mostraram que existem 290 árvores antigas e famosas, compreendendo 42 espécies, 34 gêneros e 26 famílias. Estes incluíram quatro tipos de árvores antigas e famosas com origens diferentes, como as árvores religiosas, árvores silvestres naturalmente preservadas, árvores agrícolas ou usadas como oferendas, e árvores exóticas originarias de outros locais. Há relativamente mais espécies nativas e comparativamente mais árvores mais velhas. Muitas árvores antigas e famosas são distribuídas na área cênica Mountain Lao e muitas delas pertencem a gêneros temperados. Atualmente, a conservação de árvores antigas e famosas no Distrito de Laoshan é desafiadora devido a questões como deterioração do habitat, efeitos severos de perigos naturais, pragas e doenças, enfraquecimento da função fisiológica e manejo inadequado. Medidas foram propostas, por exemplo, inspecionar regularmente árvores antigas e famosas, restaurar seus habitats, reforçar controles de pragas e doenças, promover estudos sobre tecnologias de conservação, melhorar práticas de manejo, aumentar subsídios e reformar o sistema de propriedade de árvores antigas e famosas.

Qualitative GIS and the Visualization of Narrative Activity Space Data.

Qualitative activity space data, i.e. qualitative data associated with the routine locations and activities of individuals, are recognized as increasingly useful by researchers in the social and health sciences for investigating the influence of environment on human behavior. However, there has been little research on techniques for exploring qualitative activity space data. This research illustrates the theoretical principles of combining qualitative and quantitative data and methodologies within the context of GIS, using visualization as the means of inquiry. Through the use of a prototype implementation of a visualization system for qualitative activity space data, and its application in a case study of urban youth, we show how these theoretical methodological principles are realized in applied research. The visualization system uses a variety of visual variables to simultaneously depict multiple qualitative and quantitative attributes of individuals' activity spaces. The visualization is applied to explore the activity spaces of a sample of urban youth participating in a study on the geographic and social contexts of adolescent substance use. Examples demonstrate how the visualization may be used to explore individual activity spaces to generate hypotheses, investigate statistical outliers, and explore activity space patterns among subject subgroups.