All-optical controllable electromagnetically induced transparency in coupled silica microbottle cavities

An all-optical control scheme of electromagnetically induced transparency (EIT) based on two coupled silica microbottle cavities coated with iron oxide nanoparticles is proposed and experimentally demonstrated. The specially designed and fabricated silica microbottle cavity with a short and spherical end, which is coated with iron oxide nanoparticles, possesses a quality (Q) factor of 1.39×108 and large all-optical tunability in a range of 282.32 GHz (2.25 nm) arising from the strong photothermal effect of the nanoparticles. Based on two coupled silica microbottle cavities, we achieve the EIT spectrum with a transparency window bandwidth of 2.3 MHz. The transparency window can be flexibly controlled by tuning the resonant frequency of the higher-Q microcavity. Besides, by tuning the resonant frequencies of the two microcavities separately, the whole EIT spectrum can be shifted with a range of 71.52 GHz, to the best of our knowledge, for the first time. Based on this scheme, we have realized all-optical and independent control of the transparency window and the whole EIT spectrum. We believe this work has great potential in applications such as light storage, optical sensing, and quantum optics

Backscattering-Induced Chiral Absorption in Optical Microresonators

Chirality in micro- and nanophotonic structures is crucial for both fundamental research and applied technology. Here, we experimentally demonstrate chiral absorption via backscattering in a single whispering-gallery microresonator under simultaneous excitation from both ports. Remarkably, this scheme does not rely on any nonlinear effects or the breaking of parity or time-reversal symmetry. These intriguing phenomena occur due to the interference between the clockwise- and counterclockwise-propagating light fields induced by the backscattering. Furthermore, we also achieve the chiral optical states in a coupled-microresonator system, which can be utilized to manipulate the electromagnetically induced transparency or absorption effect. Our work proposes a linear and all-optical scheme to realize chiral optical states, which can help control the light flow in photonic systems with a high operation rate

Allelopathic Effect of <i>Serphidium kaschgaricum</i> (Krasch.) Poljak. Volatiles on Selected Species

The chemical profile and allelopathic effect of the volatile organic compounds (VOCs) produced by a dominant shrub Serphidium kaschgaricum (Krasch.) Poljak. growing in northwestern China was investigated for the first time. Serphidium kaschgaricu was found to release volatile compounds into the surroundings to affect other plants’ growth, with its VOCs suppressing root elongation of Amaranthus retroflexus L. and Poa annua L. by 65.47% and 60.37% at 10 g/1.5 L treatment, respectively. Meanwhile, volatile oils produced by stems, leaves, flowers and flowering shoots exhibited phytotoxic activity against A. retroflexus and P. annua. At 0.5 mg/mL, stem, leaf and flower oils significantly reduced seedling growth of the receiver plants, and 1.5 mg/mL oils nearly completely prohibited seed germination of both species. GC/MS analysis revealed that among the total 37 identified compounds in the oils, 19 of them were common, with eucalyptol (43.00%, 36.66%, 19.52%, and 38.68% in stem, leaf, flower and flowering shoot oils, respectively) and camphor (21.55%, 24.91%, 21.64%, and 23.35%, respectively) consistently being the dominant constituents in all oils. Eucalyptol, camphor and their mixture exhibited much weaker phytotoxicity compared with the volatile oils, implying that less abundant compounds in the volatile oil might contribute significantly to the oils’ activity. Our results suggested that S. kaschgaricum was capable of synthesizing and releasing allelopathic volatile compounds into the surroundings to affect neighboring plants’ growth, which might improve its competitiveness thus facilitate the establishment of dominance

Total biflavonoids extraction from Selaginella chaetoloma utilizing ultrasound-assisted deep eutectic solvent: Optimization of conditions, extraction mechanism, and biological activity in vitro

In this study, the deep eutectic solvent based ultrasound-assisted extraction (DES-UAE) was investigated for the efficient and environmentally friendly extraction of Selaginella chaetoloma total biflavonoids (SCTB). As an extractant for optimization, tetrapropylaminium bromide-1,4-butanediol (Tpr-But) was employed for the first time. 36 DESs were created, with Tpr-But producing the most effective results. Based on response surface methodology (RSM), the greatest extraction rate of SCTB was determined to be 21.68 ± 0.78 mg/g, the molar ratio of HBD to HBA was 3.70:1, the extraction temperature was 57 °C, and the water content of DES was 22 %. In accordance with Fick's second rule, a kinetic model for the extraction of SCTB by DES-UAE has been derived. With correlation coefficients 0.91, the kinetic model of the extraction process was significantly correlated with the general and exponential equations of kinetics, and some important kinetic parameters such as rate constants, energy of activation and raffinate rate were determined. In addition, molecular dynamics simulations were used to study the extraction mechanisms generated by different solvents. Comparing the effect of several extraction methods on S.chaetoloma using ultrasound-assisted extraction and conventional methods, together with SEM examination, revealed that DES-UAE not only saved time but also enhanced SCTB extraction rate by 1.5–3 folds. SCTB demonstrated superior antioxidant activity in three studies in vitro. Furthermore, the extract could suppress the growth of A549, HCT-116, HepG2, and HT-29 cancer cells. Alpha-Glucosidase (AG) inhibition experiment and molecular docking studies suggested that SCTB exhibited strong inhibitory activity against AG and potential hypoglycemic effects. The results of this study indicated that a Tpr-But-based UAE method was suitable for the efficient and environmentally friendly extraction of SCTB, and also shed light on the mechanisms responsible for the increased extraction efficiency, which could aid in the application of S.chaetoloma and provide insight into the extraction mechanism of DES

Density Management Is More Cost Effective than Fertilization for <i>Chimonobambusa pachystachys</i> Bamboo-Shoot Yield and Economic Benefits

Stand-density management and fertilization practices are the main two factors affecting bamboo-shoot yield. However, the appropriate density and fertilization rates are still unclear for improving the bamboo-shoot yield and its economic benefits, especially for a high economic value bamboo-shoot forest. To fill this gap, we conducted a two-year split-plot design experiment in a Chimonobambusa pachystachys shoot forest. The main plots were assigned to five density rates, 40,000, 50,000, 60,000, 70,000, and 100,000 culms ha−1, and the subplots were assigned to four fertilization rates (nitrogen:phosphorus:potassium = 23:3:15): 0, 820, 1640, and 2460 kg ha−1 a−1. Results showed that the bamboo-shoot yield increased first and then decreased with stand density, while it increased with fertilization rates. Density management and fertilization regulate bamboo-shoot yield by changing the soil’s Olsen P, available nitrogen, organic matter, and available potassium contents. The maximum bamboo-shoot yield was 9315.92 kg ha−1, which appeared in the density of 60,000 culms ha−1 and the fertilization of 2460 kg ha−1 a−1. However, the maximum bamboo-shoot net profit was 135,242.63 CNY ha−1, which appeared at the density of 60,000 culms ha−1 and the fertilization of 1640 kg ha−1 a−1. The economic-benefit analysis shows that density management achieves a net-profit growth comparable to fertilizer application at a much lower cost. The study results provide a basis for the scientific management of C. pachystachys shoot forests and bamboo farmers to improve their income

Microvessels derived from hiPSCs are a novel source for angiogenesis and tissue regeneration

The establishment of effective vascularization represents a key challenge in regenerative medicine. Adequate sources of vascular cells and intact vessel fragments have not yet been explored. We herein examined the potential application of microvessels induced from hiPSCs for rapid angiogenesis and tissue regeneration. Microvessels were generated from human pluripotent stem cells (iMVs) under a defined induction protocol and compared with human adipose tissue-derived microvessels (ad-MVs) to illustrate the similarity and differences of the alternative source. Then, the therapeutic effect of iMVs was detected by transplantation in vivo. The renal ischemia-reperfusion model and skin damage model were applied to explore the potential effect of vascular cells derived from iMVs (iMVs-VCs). Besides, the subcutaneous transplantation model and muscle injury model were established to explore the ability of iMVs for angiogenesis and tissue regeneration. The results revealed that iMVs had remarkable similarities to natural blood vessels in structure and cellular composition, and were potent for vascular formation and self-organization. The infusion of iMVs-VCs promoted tissue repair in the renal and skin damage model through direct contribution to the reconstruction of blood vessels and modulation of the immune microenvironment. Moreover, the transplantation of intact iMVs could form a massive perfused blood vessel and promote muscle regeneration at the early stage. The infusion of iMVs-VCs could facilitate the reconstruction and regeneration of blood vessels and modulation of the immune microenvironment to restore structures and functions of damaged tissues. Meanwhile, the intact iMVs could rapidly form perfused vessels and promote muscle regeneration. With the advantages of abundant sources and high angiogenesis potency, iMVs could be a candidate source for vascularization units for regenerative medicine

High drug loading hydrophobic cross-linked dextran microspheres as novel drug delivery systems for the treatment of osteoarthritis

Drug delivery via intra-articular (IA) injection has proved to be effective in osteoarthritis (OA) therapy, limited by the drug efficiency and short retention time of the drug delivery systems (DDSs). Herein, a series of modified cross-linked dextran (Sephadex, S0) was fabricated by respectively grafting with linear alkyl chains, branched alkyl chains or aromatic chain, and acted as DDSs after ibuprofen (Ibu) loading for OA therapy. This DDSs expressed sustained drug release, excellent anti-inflammatory and chondroprotective effects both in IL-1β induced chondrocytes and OA joints. Specifically, the introduction of a longer hydrophobic chain, particularly an aromatic chain, distinctly improved the hydrophobicity of S0, increased Ibu loading efficiency, and further led to significantly improving OA therapeutic effects. Therefore, hydrophobic microspheres with greatly improved drug loading ratio and prolonged degradation rates show great potential to act as DDSs for OA therapy

Comparison of viral communities in the blood, feces and various tissues of wild brown rats (Rattus norvegicus)

Viral diseases caused by new outbreaks of viral infections pose a serious threat to human health. Wild brown rats (Rattus norvegicus), considered one of the world's largest and most widely distributed rodents, are host to various zoonotic pathogens. To further understand the composition of the virus community in wild brown rats and explore new types of potentially pathogenic viruses, viral metagenomics was conducted to investigate blood, feces, and various tissues of wild brown rats captured from Zhenjiang, China. Results indicated that the composition of the virus community in different samples showed significant differences. In blood and tissue samples, members of the Parvoviridae and Anelloviridae form the main body of the virus community. Picornaviridae, Picobirnaviridae, and Astroviridae made up a large proportion of fecal samples. Several novel genome sequences from members of different families, including Anelloviridae, Parvoviridae, and CRESS DNA viruses, were detected in both blood and other samples, suggesting that they have the potential to spread across organs to cause viremia. These viruses included not only strains closely related to human viruses, but also a potential recombinant virus. Multiple dual-segment picornaviruses were obtained from fecal samples, as well as virus sequences from the Astroviridae and Picornaviridae. Phylogenetic analysis showed that these viruses belonged to different genera, with multiple viruses clustered with other animal viruses. Whether they have pathogenicity and the ability to spread across species needs further study