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Parkinson's disease (PD) is the second most common degenerative disease of the central nervous system (CNS) after Alzheimer's disease. In addition to the typical motor symptoms, the clinical manifestations of patients with PD include gastrointestinal symptoms, which even precede the motor symptoms. Recent research has found that the gut microbiota regulates the brain-gut axial interaction through immune, endocrine, and direct neural mechanisms, supporting the hypothesis that the pathological process of PD spreads from the gut to the brain. In this review article, we highlight the landmark findings in the field of PD, with particular attention to the brain-gut-microbiota axis. We summarize the changes and their clinical effects on the gut microbiota and metabolites observed in PD. The intestinal microbiota may contain appropriate targets for the prevention and treatment of PD. Clinical cohort studies suggest that certain intestinal microbes have protective or pathogenic effects on the progression of PD. A better understanding of the interaction between the gut-brain axis, the gut microbiota, and PD has the potential to lead to new diagnostic and therapeutic approaches. Animal experiments suggest that fecal microbiota transplantation (FMT) is helpful for treating PD, and FMT is expected to be an effective treatment for PD in the future.

Several studies have identified an association between the gut microbiome and post-stroke depression (PSD). As a common gastric infection bacteria, Helicobacter pylori (H. pylori) infection cause significant alterations in the composition of the gastrointestinal microbiome, but relationship between H. pylori infection and PSD is still limited. Here, we conducted a retrospective study to assess risk factors associated with PSD. A total of 183 patients with ischemic stroke were enrolled and their depression scores, imaging features and clinical data were analyzed. Multivariate logistic regression analysis showed that deep white matter lesions (DWMLs) and H. pylori infection were the independent risk factors for PSD. Further analysis indicated that patients with H. pylori-positive infection [H. pylori (+)] had more severe depressive symptoms than those with negative infection [H. pylori (-)]. Fecal 16S rRNA gene sequencing analysis revealed statistically differences in intestinal flora between H. pylori (+) patients and H. pylori (-) patients. The DESeq2 analysis indicated that Akkermansia muciniphila, Bacteroides dorei, and Fusobacterium ulcerans levels were significantly decreased, while Megamonas funiformis and Bifidobacterium adolescentis were more abundant in the H. pylori (+) group. GC-MS revealed that short-chain fatty acids (SCFAs) concentrations were significantly different between the two groups, and fecal SCFAs concentrations reduced in the H. pylori (+) group. In conclusion, DWMLs and H. pylori infection may play important roles in the development of PSD. H. pylori infection is likely to be involved in the pathogenesis of PSD by altering the intestinal flora.

Guided-mode resonance (GMR) bandpass filters have many important applications. The tolerance of fabrication errors that easily cause the transmission wavelength to shift has been well studied for one-dimensional (1D) anisotropic GMR gratings. However, the tolerance of two-dimensional (2D) GMR gratings, especially for different design architectures, has rarely been explored, which prevents the achievement of a high-tolerance unpolarized design. Here, GMR filters with common 2D zero-contrast gratings (ZCGs) were first investigated to reveal their differences from 1D gratings in fabrication tolerance. We demonstrated that 2D ZCGs are highly sensitive to errors in the grating linewidth against the case of 1D gratings, and the linewidth orthogonal to a certain polarization direction has much more influence than that parallel to the polarization. By analyzing the electromagnetic fields, we found that there was an obvious field enhancement inside the gratings, which could have a strong effect on the modes in the waveguide layer through the field overlap. Therefore, we proposed the introduction of an etch-stop (ES) layer between the gratings and the waveguide-layer, which can effectively suppress the interaction between the gratings and modal evanescent fields, resulting in 4-fold increased tolerance to the errors in the grating linewidth. Finally, the proposed etch-stop ZCGs (ES-ZCGs) GMR filters were experimentally fabricated to verify the error robustness.

Littrow diffraction, the ability to reflect light back along incident direction, is a key functionality of retroreflectors, exhibiting wide applications in nanophotonics. However, retroreflectors have hitherto low working efficiencies and narrow bandwidths, and work only for a specific polarization, being unfavorable for integration-optics applications. Here, we propose a type of metagrating consisting of an all-dielectric Bragg reflector and a periodic metasurface with freeform-shaped dielectric resonators, which enables broadband depolarized perfect Littrow diffraction at optical frequencies. The physics is governed by exact cancellations of specular reflections contributed by two Bragg modes in metagratings, enabled by careful structural optimization to yield the desired reflection-phase difference of Bragg modes within a wide frequency band and for two polarizations. As a proof of concept, we experimentally demonstrate retroreflections with unpolarized absolute efficiency higher than 98% (99% in design) at 1030–1090 nm using multilayer freeform metagratings. Our results pave the way for numerous applications based on high-efficiency Littrow diffraction (e.g., spectral laser beam combining), which is not bonded to a specific polarization or frequency.

Pixelated filter arrays of Fabry-Perot (FP) cavities are widely integrated with photodetectors to achieve a WYSIWYG (“what you see is what you get”) on-chip spectral measurements. However, FP-filter-based spectral sensors typically have a trade-off between their spectral resolution and working bandwidth due to design limitations of conventional metal or dielectric multilayer microcavities. Here, we propose a new idea of integrated color filter arrays (CFAs) consisting of multilayer metal-dielectric-mirror FP microcavities that, enable a hyperspectral resolution over an extended visible bandwidth (∼300 nm). By introducing another two dielectric layers on the metallic film, the broadband reflectance of the FP-cavity mirror was greatly enhanced, accompanied by as-flat-as-possible reflection-phase dispersion. This resulted in balanced spectral resolution (∼10 nm) and spectral bandwidth from 450 nm to 750 nm. In the experiment, we used a one-step rapid manufacturing process by using grayscale e-beam lithography. A 16-channel (4 × 4) CFA was fabricated and demonstrated on-chip spectral imaging with a CMOS sensor and an impressive identification capability. Our results provide an attractive method for developing high-performance spectral sensors and have potential commercial applications by extending the utility of low-cost manufacturing process.

Diffractive optical elements (DOEs) play an important role in modern optical applications such as spectral and imaging systems, but it is challenging to balance the diffraction efficiency with the working bandwidth. The core issue is controlling the broadband dispersion of all phase units to achieve achromatic 2π-phase modulation in the broadband domain. Here, we demonstrate broadband DOEs utilizing multilayer subwavelength structures with different materials, making it possible to freely control the phase and phase dispersion of the structural units on a much larger scale than monolayer structures. The desired dispersion-control abilities arose due to a dispersion-cooperation mechanism and vertical mode-coupling effects between the top and bottom layers. An infrared design comprised of two vertically concatenated TiO2 and Si nanoantennas separated by a SiO2 dielectric spacer layer was demonstrated. It showed an average efficiency of over 70% in the three-octave bandwidth. This work shows enormous value for broadband optical systems with DOEs such as spectral imaging and augmented reality.

In the OLSR protocol, MPR set is selected as the node of relay broadcast in the process of broadcast flooding, but in some cases the MPR set selected by traditional OLSR protocol is not optimal, which will lead to unnecessary data forwarding and waste of resources. Aiming at the deficiency of classical algorithm, a new algorithm of reverse thinking is proposed. By combining cyclic and set operations, invalid redundant nodes can be eliminated effectively. This algorithm not only achieves the effect of traditional OLSR protocol, but also has lower data overhead and higher efficiency than traditional OLSR protocol. Using the OPNET simulation tool, the MPR set selection algorithm is redefined. Simulation results show that the algorithm has a certain increase in the success rate of data transmission in the network.

Due to the prevalence of high-fat diets and lack of exercise, diseases related to nutrient metabolism such as nonalcoholic fatty liver disease (NAFLD) have become one of the reasons causes endangering human liver health. Maslinic acid (MA) is a pentacyclic triterpenoid acid that is abundant in fruits such as hawthorn and jujube. In this study, we investigated the effect of MA on NAFLD to inform the development of dietary supplements for the treatment and prevention of NAFLD.The NAFLD model was established by feeding mice a high-fat diet (HFD). HEPG2 cells were treated with oleic acid and used as a cell culture model. Testing kits, haematoxylin and eosin staining, oil red O staining, western blotting, and immunofluorescence were performed with in vivo and in vitro experiments.The current study revealed that MA significantly reduced liver weight, body weight and serum lipid levels, and protected against liver steatosis and injury induced by a HFD. MA increased the expression of Beclin1, ATG1, and Bcl-2 mRNA and protein while decreasing the expression of TNF-α and IL-1β, caspase-3 and Bax mRNA and protein. Beclin1, and ATG1 were obviously increased, and the mRNA and protein expression of TNF-α and IL-1β were obviously reduced, the mRNA and protein expression of Caspase-3 and Bax were obviously reduced, and the mRNA and protein expression of Bax were obviously increased by MA.MA reduces the content of fat in the liver cells of NAFLD mice through lipophagy activitiy and reduces inflammation and apoptosis injury.

In order to effectively describe and manage computer network traffic, this paper proposes a new method based on logarithmic barrier and queuing method (Logarithmic Barrier and Queuing Method, LBQM). This method first analyzes the key factors that affect the network traffic by using the logarithmic barrier function, and then dynamically adjusts the network distributed packet send rate by using the logarithmic barrier method and the node queue congestion situation, so that the network can obtain the maximum aggregate utility. Finally, the simulation results show that, compared network simplex algorithm and distance-directed augmenting path algorithm, LBQM has better adaptability and robustness.

Abnormal reflection is one of the most basic functions of metasurface and its efficiency is very important in practical application. The implementation of perfect anomalous reflection needs to meet both phase and amplitude requirements. However, due to the absorption loss of metal materials and transmission loss of dielectric materials, perfect abnormal reflection is difficult to be realized in optical frequency. Here, we propose a multi-layer all-dielectric metasurface structure, using the reflecting layer to reflect all of this energy back to meet the amplitude requirement of 100% reflectivity. As proof of this concept, a 30° perfect anomalous reflector at 1550 nm for TM polarized light is showed. It is worth noting that this approach is not limited to anomalous reflection but can be extended to more complex metasurface functions such as focusing.

To improve the performance of TiO2/SiO2 broadband antireflection (BBAR) coating prepared using ion assisted deposition, a hybrid approach was proposed to probe, deduce, and compensate for the thickness errors resulting from quartz crystal monitoring. Using transmission electron microscopy (TEM), a thickness-dependent relative error was found in the prepared BBAR coating. Thinner layer had larger relative error and this was the main reason for the degradation of the performance of the BBAR coating. By fitting the thickness errors via a linear model, the origin of the thickness-dependent relative error is determined to be a constant thickness offset of the quartz crystal monitor. The thickness offsets are 1.5 nm and 2.7 nm for TiO2 and SiO2, respectively. Finally, an approach through reverse engineering of a 4-layer coating was proposed to obtain the offsets for both materials. The results achieved are comparable to that obtained using TEM, but this approach is much more convenient. After compensating these offsets, a BBAR coating was prepared with transmittance higher than 99% from 450 to 900 nm.

With the ever-increasing laser power and repetition rate, thermal control of laser media is becoming increasingly important. Except for widely used air cooling or a bonded heat sink, water cooling of a laser medium is more effective in removing waste heat. However, how to protect deliquescent laser media from water erosion is a challenging issue. Here, novel waterproof coatings were proposed to shield Nd:Glass from water erosion. After clarifying the dependence of the waterproof property of single layers on their microstructures and pore characteristics, nanocomposites that dope SiO2 in HfO2 were synthesized using an ion-assisted co-evaporation process to solve the issue of a lack of a high-index material that simultaneously has a dense amorphous microstructure and wide bandgap. Hf0.7Si0.3O2/SiO2 multifunctional coatings were finally shown to possess an excellent waterproof property, high laser-induced damage threshold (LIDT) and good spectral performance, which can be used as the enabling components for thermal control in high-power laser cavities.

Objective To explore the inhibition of the proliferation of vulvar squamous cell carcinoma (VSCC) by astragaloside IV. Methods MTT examined the cell proliferation of VSCC. Flow cytometry analyzed cell cycle and apoptosis. Western blot assay detected the expression of some relevant proteins. Results AS-IV reduced the proliferation of SW962 cells in a concentration- and time-dependent manner, induced cell-cycle arresting in G0/G1 phase, as demonstrated by the up-regulation of P53 and P21 expression, and the down-regulation of cyclin D1 expression. AS-IV enhanced the expression of Bax and cleaved-caspase 3, and suppressed Bcl-2 and Bcl-xl expression, which resulted in apoptosis increased. Furthermore, the expression of Beclin-1 and LC3-B was upregulated and that of P62 was downregulated, which suggested that AS-IV could increase the incidence of autophagy in SW962 cells. After inhibiting autophagy by 3-methyladenine (3-MA), cell apoptosis decreased upon AS-IV treatment. Similarly, TGF-β1 stimulated SW962 cells, cell proliferation enhanced, and the expression of TGF-βRII and Smad4 was decreased. Furthermore, the expression of proteins that promote apoptosis and autophagy decreased. After AS-IV treatment, the expression levels of the above proteins exhibited the opposite effect. Conclusion AS-IV inhibits cell proliferation and induces apoptosis and autophagy through the TGF-β/Smad signaling pathway in VSCC.

Optimal solution for the multilayers AR coating of 4J solar cell including design and fabrication was investigated. The real layer structure of 4J solar cell was determined first through reverse fitting, then the multilayers AR coating could be designed on the complete 4J solar cell to find the global optimization. After clarifying that the performance of multilayers AR coating is affected by oxidation of AlInP, the oxide layer was characterized and compensated to improve the spectrum. Through transmission electron microscopy (TEM), the oxidation depth was determined to be 5nm. Finally, the multilayers AR coating was re-optimized by considering oxidation layer into 4J solar cell. Using ion assisted deposition, the multilayers AR coating was fabricated with a slightly increased weight average reflectance of only 0.5%.

Laser damage of zigzag slab lasers occurs at interface between laser crystal and SiO2 film. Although an additional HfO2 layer could be used to manipulate electric-field on the crystal-film interface, their high absorption and polycrystalline structure were unacceptable. SiO2 was then doped in HfO2 to suppress its crystallization and to achieve low absorption by annealing. HfxSi1−xO2 nanocomposite layers were then inserted between laser crystal and SiO2 film to minimize electric-field at crystal-film interface. Laser damage resistance of this new architecture is two times higher than that of traditional zigzag slab lasers.

For the sol-gel method, it is still challenging to achieve excellent spectral performance when preparing antireflection (AR) coating by this way. The difficulty lies in controlling the film thickness accurately. To correct the thickness error of sol-gel coating, a hybrid approach that combined conventional sol-gel process with ion-beam etching technology was proposed in this work. The etching rate was carefully adjusted and calibrated to a relatively low value for removing the redundant material. Using atomic force microscope (AFM), it has been demonstrated that film surface morphology will not be changed in this process. After correcting the thickness error, an AR coating working at 1064 nm was prepared with transmittance higher than 99.5%.

To solve hidden-terminal and exposed-terminal problems, an improved multi-channel MAC protocol (IMCMP) is proposed based on the existing multi-channel MAC protocol (MCMP). With the network simulation tool NS-2 (Network Simulator 2), the simulated experiments on the 802.11 protocol, MCMP and IMCMP are carried out. The simulation results show that under the different network loads and different channel numbers conditions, compared with the two performance indexes that are the MAC layer packet loss and the network end-to-end transmission delay, the performance of the proposed IMCMP protocol is superior to MCMP protocol.

Photovoltaic-thermoelectric hybrid systems that operate in steady state have attracted considerable attention due to the possibility of supplying more power output than the photovoltaic cell alone. In real life, however, the solar energy continually changes during a day, thus rendering the assumption of steady state unrealistic. In this study, we have investigated such time-dependent systems by following the trajectory of the sun between sunrise and sunset. Computed results of thermal efficiencies are parametrized in heat transfer coefficients, the thermal conductivities of the thermoelectric module, and Seebeck coefficients. For values of the Seebeck coefficient greater than 2.13 × 10−3 V/K thermal efficiencies of the hybrid system appear higher than those of the photovoltaic cells alone. To tackle the strong nonlinear coupling between nodal temperatures, and power outputs, we have adopted two-stage iterative schemes.

A nanopillar assisted multilayer antireflection (AR) coating that combines the Ta2O5/SiO2 multilayer with SiO2 nanopillars was investigated to improve the light absorption of quadruple-bandgap photovoltaics. After clarifying that the performance of the traditional multilayer AR coating is restricted by the available refractive index of the top layer, periodic SiO2 rhombic nanopillars that work in the subwavelength regime were used to vary its effective index from 1 to 1.46. Then, the effective index and thickness of SiO2 nanopillars were optimized together with the Ta2O5/SiO2 stack using the global optimization algorithm to further reduce the reflection loss. When the SiO2 nanopillars have an effective index of 1.15 and a thickness of 108 nm, the best AR performance was achieved with a reflectance of 3.9% in the target spectral range of 300–1700 nm. Using laser interference lithography and ion assisted deposition technologies, the nanopillar assisted AR coating was realized with a reflectance of 4.5%. Compared to the traditional multilayer AR coating, this hybrid approach can not only achieve better AR performance but also reduce the disparities of the reflection loss among different bandgaps, which helps us to effectively improve the current matching and enhance the overall efficiency of quadruple-bandgap photovoltaics.A nanopillar assisted multilayer antireflection (AR) coating that combines the Ta2O5/SiO2 multilayer with SiO2 nanopillars was investigated to improve the light absorption of quadruple-bandgap photovoltaics. After clarifying that the performance of the traditional multilayer AR coating is restricted by the available refractive index of the top layer, periodic SiO2 rhombic nanopillars that work in the subwavelength regime were used to vary its effective index from 1 to 1.46. Then, the effective index and thickness of SiO2 nanopillars were optimized together with the Ta2O5/SiO2 stack using the global optimization algorithm to further reduce the reflection loss. When the SiO2 nanopillars have an effective index of 1.15 and a thickness of 108 nm, the best AR performance was achieved with a reflectance of 3.9% in the target spectral range of 300–1700 nm. Using laser interference lithography and ion assisted deposition technologies, the nanopillar assisted AR coating was realized with a reflectance of 4.5%. Com...

In order to make quantitative research on network traffic, this paper puts forward a kind of prediction algorithm based on the queue length of steady state for FARIMA model, PQSF. The algorithm firstly uses the theory of product solution based on the queue length of steady state to derive node packet queuing situation, then calculates the mathematical formula of the traffic's average queue length when there are failure nodes, and establishes the prediction method combined with FARIMA. Finally, this paper validates the PQSF algorithm by the network simulation. The results show that the algorithm has comparatively good adaptability.

Through reverse engineering of the fabricating the broadband antireflection coating, the error compensation strategy in quartz crystal monitoring was proposed. And its accuracy and importance throughout the fabrication process is also demonstrated.

Hepatitis B vaccination typically requires a multi-dose administration protocol over a course of 3–6 months. Aiming at developing a single-shot formulation for hepatitis B vaccine (hepatitis B surface antigen (HBsAg)), a novel vaccine delivery system, the composite microspheres of alginate–chitosan–poly(lactic-co-glycolic acid) (PLGA), was synthesized by a two-step preparation. The composite microspheres showed distinct advantages over the conventional PLGA microspheres in aspects of the high loading capacity and the elimination of lyophilizing process. The loading capacity of the composite microspheres was about seven times higher than those in the conventional PLGA microspheres, due to the protein-friendly microenvironment created by the hydrophilic alginate–chitosan cores of the composite microspheres. This vaccine delivery system was shown to be able to induce robust immune responses by single injection and display no significant difference in HBsAg-specific antibody levels compared to the double-injection method.

Effective sustained delivery systems are in urgent demand for patients receiving long-term medication (e.g., for schizophrenia), as poor compliance often leads to unproductive treatments. Although the conventional PLGA-based implants have been extensively studied for sustained delivery, they require invasive surgical operations. A more challenging problem is the burst release effect that is characteristic of these systems. Presented here is a novel, hybrid PLGA injectable implant for long-acting risperidone for improved antipsychotic treatment, avoiding pitfalls of the oral form such as poor bioavailability, short half-life and wide fluctuation of blood drug concentrations. This hybrid solid lipid/PLGA implant (S/P-I) is formed in situ following intramuscular injection. The unique advantages of incorporating solid lipid are the improved drug release profiles and reduced burst effect by altering the morphology and phase inversion of the implant, as well as the improved injectability. This hybrid system shows the improved in vitro sustained drug release profiles, significantly reducing the burst effect. In vivo studies show the prolonged mean residence time (MRT) of 86.8 h for S/P-I, compared with 5.8 h for the risperidone solution and 32.6 h for the PLGA implant. Notably, S/P-I also displays a relatively high bioavailability at 87.8%, indicating nearly complete drug release, which is not typical in conventional PLGA-based sustained drug delivery systems. The in vivo S/P-I underwent almost complete biodegradation, with less than 2% remaining after 28 days. The findings provide a simple, yet useful and effective solution for controlling the burst effect in PLGA implant systems with glyceryl monostearate as controlled release component. S/P-I is a promising system for long-acting risperidone for improved antipsychotic treatment.