Stably polarized 795 nm vertical-cavity surface-emitting lasers with anti-phase SiNx surface gratings.

795 nm vertical-cavity surface-emitting lasers (VCSELs) with dielectric surface gratings to control the output polarization are designed and fabricated. The calculated results demonstrate that a well-designed S i N x surface grating positioned on the surface of an anti-phase VCSEL structure enhances the reflectivity difference between the two polarization modes compared to a conventional GaAs surface grating, consequently resulting in a larger gain anisotropy in VCSELs and a high orthogonal polarization suppression ratio (OPSR). Characterization shows that a peak-to-peak OPSR of 30.3 dB is achieved at 85°C for 795 nm VCSELs with a S i N x surface grating of 5 µm in diameter and an oxide aperture of ∼4µm, demonstrating the effectiveness of the S i N x surface grating in polarization control for 795 nm VCSELs.

Origins of the short circuit current of a current mismatched multijunction photovoltaic cell considering subcell reverse breakdown.

In the photovoltaic community, short circuit current (Isc) of a current mismatched multijunction photovoltaic (MJPV) cell was usually thought to be limited by the lowest subcell photocurrent (Imin). However, under certain conditions for multijunction solar cells, Isc≠Imin was observed by researchers, while this effect has not been studied in multijunction laser power converters (MJLPCs). In this work, we provide an in-depth analysis of the formation mechanisms for the Isc of the MJPV cell by measuring I-V curves of the GaAs and InGaAs LPCs with different number of subcells and simulating the I-V curves with the reverse breakdown of each subcell considered. It is found that Isc of an N-junction PV cell can be theoretically equal to any current value within a range from a current lower than Imin to the maximum subcell photocurrent, which is up to the number of subcell current steps in the forward biased I-V curve. An MJPV cell with a constant Imin will demonstrate a higher Isc if it has more subcells, smaller subcell reverse breakdown voltage and smaller series resistance. As a result, Isc tends to be limited by the photocurrent of a subcell closer to the middle cell and is less sensitive to the optical wavelength than Imin. This should be another possible reason why the measured EQE of a multijunction LPC exhibits a wider spectrum width than the calculated Imin-based EQE, whereas this was usually attributed to the luminescent coupling effect merely.

Stability Analysis of a Delayed Rumor Propagation Model with Nonlinear Incidence Incorporating Impulsive Vaccination.

The presence of information asymmetry can hinder the public's ability to make well-informed decisions, resulting in unwarranted suspicion and the widespread dissemination of rumors. Therefore, it is crucial to provide individuals with consistent and dependable scientific education. Regular popular science education is considered a periodic impulsive intervention to mitigate the impact of information asymmetry and promote a more informed and discerning public. Drawing on these findings, this paper proposes a susceptible-hesitant-infected-refuting-recovered (SHIDR) rumor-spreading model to explain the spread of rumors. The model incorporates elements such as time delay, nonlinear incidence, and refuting individuals. Firstly, by applying the comparison theorem of an impulsive differential equation, we calculate two thresholds for rumor propagation. Additionally, we analyze the conditions of global attractiveness of the rumor-free periodic solution. Furthermore, we consider the condition for the rumor's permanence. Finally, numerical simulations are conducted to validate the accuracy of our findings. The results suggest that increasing the proportion of impulsive vaccination, reducing the impulsive period, or prolonging the delay time can effectively suppress rumors.

[Progress on three-dimensional cell culture technology and their application].

Three-dimensional (3D) cell culture model is a system that co-culture carriers with 3D structural materials and different types of cells in vitro to simulate the microenvironment in vivo. This novel cell culture model has been proved to be close to the natural system in vivo. In the process of cell attachment, migration, mitosis and apoptosis, it could produce biological reactions different from that of monolayer cell culture. Therefore, it can be used as an ideal model to evaluate the dynamic pharmacological effects of active substances and the metastasis process of cancer cells. This paper compared and analyzed the different characteristics of cell growth and development under two-dimensional (2D) and 3D model culture and introduced the establishment method of 3D cell model. The application progress of 3D cell culture technology in tumor model and intestinal absorption model was summarized. Finally, the application prospect of 3D cell model in the evaluation and screening of active substance was revealed. This review is expected to provide reference for the development and application of new 3D cell culture models.

Polarization control of 795 nm vertical-cavity surface-emitting lasers by in-phase surface gratings.

795 nm vertical-cavity surface-emitting lasers (VCSELs) with in-phase surface gratings are fabricated and investigated theoretically and experimentally. The polarization characteristics of 795 nm VCSELs with various grating periods and depths are analyzed using the rigorous coupled-wave analysis (RCWA) method; the dependence of polarization stability on the profile of gratings demonstrates that the trapezoid grating ridge slightly enhances the orthogonal polarization suppression ratio (OPSR), but increases the threshold current. The fabricated VCSELs with a sub-wavelength in-phase surface grating of a duty cycle of 0.5 show stabilized output polarization at the cost of increasing the threshold current which is in agreement with the calculations. The grating VCSELs with a period of 200 nm and an oxide aperture of 3.43µm×4.39µm produce a single-mode output with an OPSR of 16.6 dB and a slope efficiency of 0.42 W/A at 85°C.

Dynamic Analysis and Optimal Control of Rumor Spreading Model with Recurrence and Individual Behaviors in Heterogeneous Networks.

This paper is devoted to investigating the impact of the recurrence of rumors and individual behaviors and control strategies related to rumor spreading in online social networks. To do this, a novel susceptible-hesitating-infected-latent-recovered (SHILR) rumor propagation model in heterogeneous networks is presented. Firstly, based on the relevant mean-field equations of the model, the threshold value is examined to demonstrate the existence and stability of rumor-free/spreading equilibrium with the help of the algebraic method. Secondly, the global stabilities of the equilibria are analyzed through applying Lyapunov stability theory and LaSalle's invariance principle. Next, the optimal control is proposed by taking advantage of Pontryagin's maximum principle for reducing the number of infected individuals with minimum cost. Moreover, some numerical examples are carried out to test the theoretical results. Finally, combined with practice, a model application is presented.

The spread and control of rumors in a multilingual environment.

This paper studies the rumor propagation model with heterogeneous networks in a multilingual environment. Firstly, a rumor propagation model with two language spreaders, in which the immunologic mechanism is considered in the ignorant, is proposed on heterogeneous networks. Secondly, the basic reproduction number and the dynamic behaviors are analyzed by using the next-generation matrix method and Lyapunov stability theory, respectively. Moreover, two control strategies are designed to effectively suppress the spread of the rumor. The one is continuous control strategy. By applying real-time control to the spreaders, the rumor spreading time can be greatly reduced and the rumor can die out in a short time. The other is event-triggered impulsive control strategy, which can effectively reduce the consumption of resources and ensure the extinction of the rumor. Finally, the correctness of theoretical analysis and the feasibility of control methods are verified by numerical simulations.

Support Morphology-Dependent Catalytic Activity of Pd/CeO2 for Formaldehyde Oxidation.

To eliminate indoor formaldehyde (HCHO) pollution, Pd/CeO2 catalysts with different morphologies of ceria support were employed. The palladium nanoparticles loaded on {100}-faceted CeO2 nanocubes exhibited much higher activity than those loaded on {111}-faceted ceria nanooctahedrons and nanorods (enclosed by {100} and {111} facets). The HCHO could be fully converted into CO2 over the Pd/CeO2 nanocubes at a GHSV of 10,000 h(-1) and a HCHO inlet concentration of 600 ppm at ambient temperature. The prepared catalysts were characterized by a series of techniques. The HRTEM, ICP-MS and XRD results confirmed the exposed facets of the ceria and the sizes (1-2 nm) of the palladium nanoparticles with loading amounts close to 1%. According to the Pd 3d XPS and H2-TPR results, the status of the Pd-species was dependent on the morphologies of the supports. The {100} facets of ceria could maintain the metallic Pd species rather than the {111} facets, which promoted HCHO catalytic combustion. The Raman and O 1s XPS results revealed that the nanorods with more defect sites and oxygen vacancies were responsible for the easy oxidation of the Pd-species and low catalytic activity.

Optimization of Preparation Conditions for Quercetin Nanoliposomes Using Response Surface Methodology and Evaluation of Their Stability.

Quercetin is a flavonol compound with excellent biological activities. However, quercetin exhibits poor stability and solubility in water, which limits its application. In this study, quercetin nanoliposomes (QUE-NL-1) were prepared using an ultrasonic thin-film dispersion method, and the preparation conditions were optimized using response surface methodology. The optimal conditions for preparing QUE-NL-1 were as follows: an evaporation temperature of 35 °C, a drug concentration of 0.20 mg/mL, and a lipid bile ratio of 4:1. The encapsulation rate of QUE-NL-1 is (63.73 ± 2.09)%, the average particle size is 134.11 nm, and the average absolute value of the zeta potential is 37.50 and PDI = 0.24. By analyzing the storage temperature, storage time, and leakage rate of QUE-NL-1 in simulated gastrointestinal fluid, it was found that quercetin exhibits good stability after embedding and can achieve sustained release in intestinal juice. In addition, the cytotoxicity of QUE-NL-1 was not significant, and the survival rate of Caco-2 cells was >90% when the concentration range of QUE-NL-1 was 0.1-0.4 mg/mL. This study provides an efficient method for preparing QUE-NL-1 with small particle sizes, good stability, and high safety, which is of great significance for expanding the application range of quercetin.

MicroRNA transcriptomes relate intermuscular adipose tissue to metabolic risk.

Intermuscular adipose tissue is located between the muscle fiber bundles in skeletal muscles, and has similar metabolic features to visceral adipose tissue, which has been found to be related to a number of obesity-related diseases. Although various miRNAs are known to play crucial roles in adipose deposition and adipogenesis, the microRNA transcriptome of intermuscular adipose tissue has not, until now, been studied. Here, we sequenced the miRNA transcriptomes of porcine intermuscular adipose tissue by small RNA-sequencing and compared it to a representative subcutaneous adipose tissue. We found that the inflammation- and diabetes-related miRNAs were significantly enriched in the intermuscular rather than in the subcutaneous adipose tissue. A functional enrichment analysis of the genes predicted to be targeted by the enriched miRNAs also indicated that intermuscular adipose tissue was associated mainly with immune and inflammation responses. Our results suggest that the intermuscular adipose tissue should be recognized as a potential metabolic risk factor of obesity.

A review on the protective effect of active components in Antrodia camphorata against alcoholic liver injury.

ETHNOPHARMACOLOGICAL RELEVANCE: Antrodia camphorata is a genus of wood-rot basidiomycete in the family Fomitopsidaceae. It is a valuable medicinal fungus in China that contains more than 78 kinds of active compounds. A. camphorata has good protection effects on the liver, especially on alcoholic liver injury (ALI). AIM: This paper summarizes the complex occurrence and development of alcoholic liver disease (ALD). In addition, the effect of ALD on the intestine through the gut-liver axis is summarized. The protective mechanism of A. camphorata on ALI is reviewed to reveal its therapeutic potential, offering insights into future research. MATERIALS AND METHODS: A comprehensive search in the literature was obtained from books and online databases such as Web of Science, Google Scholar, PubMed, Scopus, Science direct, ACS Publications and Baidu Scholar. RESULTS: The pathogenesis of ALD mainly includes oxidative stress injury, intestinal microflora imbalance, inflammatory mediator injury and nutritional imbalance. A. camphorata contains rich active components (e.g. polysaccharides, triterpenoids, maleic and succinic acid derivatives, amino acids, superoxide dismutase, vitamins, lignin and sterols). These components have good antioxidant, anti-inflammatory and intestinal protection activities. Therefore, A. camphorata has a wide application in the prevention and treatment of ALI. CONCLUSIONS: ALD develops from a mild disease to alcoholic hepatitis and cirrhosis, which is the main reason of global morbidity and mortality. At present, there is no effective drug for the treatment of ALD. A. camphorata, as a valuable medicinal fungus unique to Taiwan, has a great protective effect on the liver. It is expected to be an effective drug for ALI treatment. Although many studies have performed the protective effects of A. camphorata on ALI, its regulatory effects on the gut-liver axis of ALD patients need to be further explored.

Photo-and thermo-regulation by photonic crystals for extended longevity of C. elegans.

Methods allowing light energy to be modulated in a controllable fashion are potentially important for finding the correlation between light-related environmental factors and aging-related lifespan. Here, we report photo- and thermo-regulation based on photonic crystals (PCs) for extended longevity of C. elegans. We show that PCs can function as a regulator of visible spectrum to tune photonic energy received by C.elegans. We provide direct evidence that lifespan depends on photonic energy, and the use of PCs reflecting blue light (440-537 nm) gives 8.3 % increasement in lifespan. We demonstrate that the exposure to modulated light alleviates photo-oxidative stress and unfolded-protein response. We realize reflective passive cooling temperature using PCs, and favorable low temperature could be created for worms to extend lifespan. This work offers a new path based on PCs to resist negative effects light and temperature for longevity, provides an available platform for studying the role of light in aging.

The role of the maximal first derivative of the radial pulse wave (Rad dP/dtmax) in monitoring cardiac function.

BACKGROUND: This study aimed to assess the clinical significance of the maximal first derivative of the radial pulse wave (Rad dP/dtmax) in monitoring cardiac function with different perioperative patients by researching the relationship between Rad dP/dtmax and cardiac output (CO). METHODS: Patients with non-pump coronary artery bypass grafting (CABG) and open liver tumor resection (OLTR) were enrolled in this study (n=10). CO was measured using the thermodilution Swan-Ganz catheter method and Rad dP/dtmax was acquired by the analysis of patients' left radial artery pressure waveform through the PowerLab data acquisition device. CO, Rad dP/dtmax, heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure, central venous pressure, mean pulmonary arterial pressure, pulmonary artery wedge pressure (PAW), and body surface area was recorded. Data were analyzed using a mixed linear model of time-dependent covariates to duplicate the data. RESULTS: The bivariate correlation coefficients of Rad dP/dtmax and CO were 0.526 and 0.413. The result of the multivariate mixed linear model analysis showed that compared with other indicators, Rad dP/dtmax had the greatest standardized coefficient with CO in CABG patients. While in OLTR patients, HR, SBP, PAW, and DBP had larger standardized coefficients. CONCLUSIONS: Rad dP/dtmax could be a useful indicator to reflect and predict the acute changes in cardiac function in perioperative patients, especially for patients with cardiac dysfunction or contractility abnormality.

Hemiparetic stroke alters vastus lateralis myosin heavy chain profiles between the paretic and nonparetic muscles.

Skeletal muscle phenotype alterations following hemiparetic stroke contribute to disabilities associated with stroke. The phenotypic response following stroke is undefined. This investigation examined the myosin heavy chain (MHC) composition of the vastus lateralis (VL) of stroke survivors in paretic (P) and nonparetic (NP) muscle. Protein obtained from VL of 10 stroke survivors was isolated and purified, and MHC gel electrophoresis was performed. The MHC bands were quantified, and a paired sample two-tailed T test with significance set at p < or = 0.05 was performed. MHC I expression was significantly less in P versus NP VL (.93 vs. 1.00 arbitrary units [AU]). Significantly more IIx MHC was found in the P versus NP VL (1.33 vs. 1.0). No significant differences in type IIa MHC (1.07 P vs. 1.00 NP) were found. These changes in MHC composition suggest an alteration in muscle function due to stroke or the altered activity patterns of muscle following stroke.

Large-Area and Water Rewriteable Photonic Crystal Films Obtained by the Thermal Assisted Air-Liquid Interface Self Assembly.

Compared with traditional paper, water rewritable photonic crystal (PC) paper is an environmentally friendly and low resource-consuming material for information storage. Although, recently reported PC papers have high-quality structure color showing promising prospect, the paper size, that is within several centimeters, still limits turning it from potential to reality. Here, we present a new water rewritable PC film as large as the A4 size (210 × 300 mm2) with a high-quality structure color. The material is prepared by thermal assisted self-assembly on the air-liquid interface. To fix such a large-area self-assembled PC film, we partially deform and coalesce the self-assembled nanoparticles, which have low glass transition temperature. This process causes the film to be transparent and structural colorless but still keeps the inner 3D-ordered structure. Then, utilizing the hydrophilic nature of the assembled block, the film can be switched to a structural color state by touching water. Diverse brilliant structural colors appear with different assembled particle (poly(butyl methacrylate- co-methylmethacrylate- co-butyl acrylate- co-diacetone acrylamide) named as PBMBD) sizes. The transparency-structural color transition can be performed multiple times reversibly in all or specific regions of the film. It provides a new solution for future applications of rewriteable PC paper.

[Effects of propofol pretreatment on myocardial cell apoptosis and SERCA2 expression in rats with hepatic ischemia/reperfusion]. / Efeitos do pré­tratamento com propofol sobre a apoptose de células miocárdicas e expressão de SERCA2 em ratos com isquemia/reperfusão hepática.

INTRODUCTION: Hepatic ischemia-reperfusion injury is a common pathophysiological process in liver surgery. Whether Propofol can reduce myocardial ischemia-reperfusion injury induced by hepatic ischemia-reperfusion injury in rats, together with related mechanisms, still needs further studies. OBJECTIVE: To investigate if propofol would protect the myocardial cells from apoptosis with hepatic ischemia-reperfusion injury. METHODS: Male Sprague-Dawley rats (n=18) were randomly allocated into three groups: Sham Group (Group S, n=6), Hepatic Ischemia-reperfusion Injury Group (Group IR, n=6) and Propofol Group (Group P, n=6). Group S was only subjected to laparotomy. Group IR was attained by ischemia for 30min and reperfusion for 4h. Group P was subjected identical insult as in Group IR with the administration of propofol started 10min before ischemia with 120mg.kg-1, following by continuous infusion at 20mg.kg-1.h-1. Cell apoptosis was examined by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay. Endoplasmic reticulum Ca2+-ATPase2 (SERCA2) and cysteine-containing aspartic acid cleaved-caspase3 (cleaved-caspase3) were assayed by western blot and Altimeter polymerase chain reaction. RESULTS: Apoptosis rate was increased, with mRNA and protein of SERCA2 down-regulated and cleaved-caspase3 up-regulated in Group IR compared with Group S (p<0.01). Apoptosis rate was decreased, with mRNA and protein of SERCA2 up-regulated and cleaved-caspase3 down-regulated in Group P compared with Group IR (p<0.01). CONCLUSIONS: Propofol can reduce hepatic ischemia-reperfusion injury-induced myocardial cell apoptosis, meanwhile, can up-regulate mRNA and protein of SERCA2 in rats.

The role of adenovirus-mediated retinoblastoma 94 in the treatment of head and neck cancer.

A truncated retinoblastoma (RB) protein of approximately 94 kDa (RB94), lacking the NH2 -terminal 112 amino acid residues of the full-length RB, has been found to have great efficacy in tumor suppression. This study investigated the role of adenovirus-mediated RB94 (Ad-RB94) gene therapy for human head and neck squamous cell carcinoma (HNSCC) and explored the cellular and molecular mechanism of tumor inhibition after Ad-RB94 gene transfer. Randomized controlled studies in vitro and in vivo were performed to assess antitumor responses of Ad-RB94 gene transfer against human HNSCC. Human HNSCC cell lines, JHU006 and JHU012, were used in this study. Tumors originated from the HNSCC cell lines were propagated as xenografts in nude mice. Ad-RB94 gene transfer was performed both in vitro and in vivo with replication-defective virus (DL312) and no treatment as controls. Transgene expression, cell viability, and tumor growth were evaluated in transfected cells and tumor implants. To determine the mechanism behind the observed antitumor action, cell cycle analysis was performed, and telomerase activity was examined. Tumors were evaluated for RB94-induced apoptosis. Transgene expression of RB94 was detected by Western blot analysis, real-time quantification reverse transcription-PCR, and immunohistochemistry. RB94 expression led to flattening of cell growth curves and caused tumor regression. Animals treated with Ad-RB94 were seen to have a significant reduction in tumor size when compared with DL312 (P = 0.02, both cell lines) and to no treatment groups (P = 0.01, both cell lines). Cell cycle arrest in the G(2)-M phase and increased levels of apoptosis occurred in tumor cells treated with Ad-RB94. In addition, telomerase activity decreased significantly and specifically after Ad-RB94 treatment. This study demonstrates that Ad-RB94 gene transfer effectively inhibits HNSCC tumor cell growth in vitro and in vivo. The unique property of Ad-RB94 gene transfer to arrest HNSCC tumor cells in the G2-M phase of the cell cycle makes it a good candidate for adjuvant therapy with radiation or chemotherapy, as tumor cells are most sensitive to radiation or cytotoxic drug in this cell cycle phase.

Design and fabrication of six-volt vertically-stacked GaAs photovoltaic power converter.

A six-volt vertically-stacked, high current GaAs photovoltaic power converter (PPC) has been designed and fabricated to produce output power over 1 W under monochromatic illumination. An N++-GaAs/P++-AlGaAs tunnel junctions (TJs) structure has been used for connecting each sub-cell in this vertically-stacked PPC device. The thickness of the each GaAs sub-cell has been derived based on the calculation of absorption depth of photons with a wavelength of 808 nm using absorption coefficient obtained from ellipsometry measurements. The devices were characterized under non-uniform CW laser illumination at 808 nm with incident power up to 4.1 W. A maximum conversion efficiency of 50.2% was achieved at 0.3 W under non-uniform (coupled in optical fiber) monochromatic illumination, dropping to 42.5% at 4.1 W. The operating voltage at the maximum power point is 5.5-6.0 V, depending on the incident laser power, and an output electrical power output of 1.3 W can be extracted at a laser power of 2.9 W and the maximum electrical power output amounts to 1.72 W. The external quantum efficiency (EQE) measurement indicates that the performance of PPC can be further improved by refining the design of the thickness of sub-cells and improving TJs.

Elevated tumor necrosis factor-alpha in skeletal muscle after stroke.

BACKGROUND AND PURPOSE: Tumor necrosis factor-alpha (TNF-alpha), an inflammatory cytokine negligibly expressed in normal muscle, is elevated in selected metabolic conditions characterized by muscle wasting and insulin resistance. Inflammation is fundamental to stroke pathogenesis. Stroke patients have gross muscular atrophy and high prevalence of diabetes and insulin resistance. Yet, no previous studies examined TNF-alpha expression in hemiparetic skeletal muscle. This study investigates whether TNF-alpha mRNA levels are elevated in paretic compared with nonparetic leg muscles of chronic ischemic stroke patients and age-matched controls. METHOD: Total RNA extracted from bilateral vastus lateralis muscle biopsies from n=20 hemiparetic stroke patients and n=9 healthy controls was reverse transcribed to cDNA, then TNF-alpha transcripts were amplified by real-time quantitative polymerase chain reaction. TNF-alpha mRNA concentrations were normalized against acidic ribosomal phosphoprotein, housekeeping gene. RESULTS: TNF-alpha mRNA levels were 2.8-fold higher in paretic compared with control leg muscle (6.28+/-1.86 versus 2.28+/-0.67; P<0.03) and 1.6-fold higher in nonparetic leg (3.71+/-1.02; P<0.11) compared with controls. There was a trend for higher TNF-alpha mRNA in paretic compared with nonparetic leg. CONCLUSIONS: Findings demonstrate increased TNF-alpha expression in paretic leg muscle, suggesting inflammatory pathways are accelerated in stroke muscle. Further studies are under way to determine whether intramuscular TNF-alpha contributes to atrophy and metabolic abnormalities after stroke.

[Preparation of Coated CMC-Fe0 Using Rheological Phase Reaction Method and Research on Degradation of TCE in Water].

The coated nanoscale zero-valent iron (coated CMC-Fe0) was synthesized with cheap and environment friendly CMC as the coating agent using rheological phase reaction. The sample was characterized by means of XRD, SEM, TEM and N2 adsorption-stripping and used to study reductive dechlorination of TCE. The experimental results indicated that the removal rate of TCE was about 100% when the CMC-Fe0 dosage was 6 g x L(-1), the initial TCE concentration was 5 mg x L(-1) and the reaction time was 40 h. The TCE degradation reaction of coated CMC-Fe0 followed a pseudo-first-order kinetic model. Finally, the product could be simply recovered.