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Solar activity, such as sunspots and flares, has a great impact on humans, living beings, and technologies in the whole world. Changes in sunspots will influence high-frequency and space-navigation radio communications. Based on the full-disk, southern and northern hemispheres sunspot areas (SAs) data in 1874–2023 from the Royal Observatory, Greenwich (RGO) USAF/NOAA, extreme value theory (EVT) is applied to predict the trend of the 25th and 26th solar cycles (SCs) in this work. Two methods with EVT, the block maxima (BM) approach and the peaks-over-threshold (POT) approach, are employed to research solar extreme events. The former method focuses on each block's maximum sunspot areas value and is applied for the generalized extreme value (GEV) distribution. The latter method aims to select the extreme values exceeding a threshold value and is used to obtain the generalized Pareto (GP) distribution. It is the first time that the EVT is applied on the sunspot areas data from the Royal Observatory, Greenwich (RGO) USAF/NOAA. The analysis indicates that the estimated 8-year return levels for sunspot areas are 5701 and 6258 using the two methods, while the estimated 19-year return levels are all 7165. This suggests that the trends of the 25th and 26th solar cycles will be stronger than that of the 24th solar cycle. [ABSTRACT FROM AUTHOR]

Glucose disturbances are a common comorbidity of major depressive disorder (MDD) patients and have been extensively studied in the past. However, few studies have explored glucose disturbances in first-episode drug-naïve (FEDN) MDD patients. The purpose of this study was to examine the prevalence and risk factors of glucose disturbances in FEDN MDD patients to understand the relationship between MDD and glucose disturbances in the acute early phase and provide important implications for therapeutic interventions. Using a cross-sectional design, we recruited a total of 1718 MDD patients. We collected their socio-demographic information, clinical data, and blood glucose indicators.17-item Hamilton Depression Rating Scale (HAMD), 14-item Hamilton Anxiety Rating Scale (HAMA), and the positive symptom subscale of the Positive and Negative Syndrome Scale (PANSS) were used to assess their depression, anxiety, psychotic symptoms, respectively. The prevalence of glucose disturbances in FEDN MDD patients was 13.6%. Depression, anxiety and psychotic symptoms, body mass index (BMI) levels and suicide attempts rates were higher in the group with glucose disorders than in the group without glucose disorders among patients with first-episode drug-naive MDD. Correlation analysis showed that glucose disturbances were associated with HAMD score, HAMA score, BMI, psychotic symptoms and suicide attempts. Furthermore, binary logistic regression showed that HAMD score and suicide attempts were independently associated with glucose disturbances in MDD patients. Our findings suggest that the prevalence of comorbid glucose disturbances is very high in FEDN MDD patients. Moreover, more severe depressive symptoms and higher suicide attempts are correlated with glucose disturbances in MDD FEDN patients in the early stage. [ABSTRACT FROM AUTHOR]

Photoresponsive fluorescent compounds have been widely used to prepare the encryption inks for modern information security. In this study, a photoresponsive fluorescent material based on dithienylethene DTE-PIO4 was synthesized by oxidizing the two sulfur atoms to sulfones. Its solution presented a distinctive fluorescence switching performance when compared with the traditional "turn-off" mode fluorescent dithienylethene, while irreversible "turn-off" fluorescence switching was observed in PMMA films and solid state upon exposure to 254 nm UV light. Remarkably, the PMMA ink was successfully prepared by incorporation with DTE-PIO4, which indicated the great potential in the fields of optical information storage and ink printing. Further research on information encryption has also been demonstrated through the blending of DTE-PIO4 with DTE-PI in PMMA medium. [ABSTRACT FROM AUTHOR]

Understanding the variations of the Walker Circulations during the Last Interglacial (LIG, ~ 130–115 ka BP) may advance our knowledge of climate change in an orbitally induced warmer world. Here we investigate the variations and the underpinning mechanisms of the Pacific Walker Circulation (PWC) and the Indian Ocean Walker Circulation (IWC) during the LIG, using the lig127k experiments from the Paleoclimate Modeling Intercomparison Project Phase 4. Compared to the preindustrial, annual PWC is broadened by 3° and strengthened by 3.5% during the LIG, whereas annual IWC is narrowed by 3° and weakened by 17.2%. The antiphase change between annual PWC and IWC during the LIG is dominated by the change in boreal warm seasons (June–October), which is in turn closely tied to the changes in sea surface temperatures between the Indian Ocean and the western Pacific Ocean. Specifically, the models predict a general warming over the tropical Indian Ocean but cooling over the tropical western Pacific in boreal warm seasons during the LIG. This interbasin contrast results in enhanced sea-level pressure over the tropical western Pacific and decreased sea-level pressure over the tropical Indian Ocean, together with opposite changes in precipitation. The west-to-east sea-level pressure gradient contributes to anomalous low-level easterlies in the deep tropics. These changes result in an enhancement and broadening of the PWC, whereas a reverse change for the IWC. The proposed dominating role of interbasin contrast in temperature anomaly is further confirmed by a linear baroclinic model and an atmospheric general circulation model. [ABSTRACT FROM AUTHOR]

The thorax is the central component of the insect flight drivetrain, making it essential to understand how thoracic muscles influence insect flight for flapping wing microair vehicle design. This paper presents a theoretical model that takes into account the influence of thoracic muscles on flapping wing motion with reference to real insects. The thoracic muscle effect is simulated by the chordwise torsional spring, whose stiffness is derived from a comparison test with the results of real insect experiments. The elastic deformation of the flexible flapping wing is modeled by the von Kármán nonlinear plate theory. The predictive quasi-steady aerodynamic model based on the blade element theory can estimate the aerodynamic force, and the modeling of the spanwise bending and twisting is done with quadratic polynomials. The equations of motion are solved using the Newmark-Raphson method. Results suggest that including the influence of thoracic muscles decreases cycle-averaged lift and power, but enhances the efficiency of lift production by 23%. Moreover, it also postpones pitching motion and reduces its amplitude, though the movement trends of the flapping motion remain approximately unchanged regardless of the inclusion of the thoracic muscle effect. [ABSTRACT FROM AUTHOR]

In this paper, we are concerned with the precise relationship between the Hausdorff dimension of possible singular point set S of suitable weak solutions and the parameter α in the nonlinear term in the following parabolic equation h t + h x x x x + ∂ x x | h x | α = f. It is shown that when 5 / 3 ≤ α < 7 / 3 , the 3 α − 5 α − 1 dimensional parabolic Hausdorff measure of S is zero, which generalizes the recent corresponding work of Ozánski and Robinson in [SIAM J. Math. Anal., 51, 228–255 (2019)] for α = 2 and f = 0. The same result is valid for a 3D modified Navier–Stokes system. [ABSTRACT FROM AUTHOR]

We study the dissociation effect of J / Ψ in magnetized, rotating QGP matter at finite temperature and chemical potential using gauge/gravity duality. By incorporating angular velocity into the holographic magnetic catalysis model, we analyze the influence of temperature, chemical potential, magnetic field, and angular velocity on the properties of J / Ψ meson. The results reveal that temperature, chemical potential, and rotation enhance the dissociation effect and increase the effective mass in the QGP phase. However, the magnetic field suppresses dissociation, and its effect on the effective mass is non-trivial. Additionally, we explore the interplay between magnetic field and rotation, identifying a critical angular velocity that determines the dominant effect. As a parallel study, we also examine the rotation effect in the holographic inverse magnetic catalysis model, although the magnetic field exhibits distinctly different behaviors in these two models, the impact of rotation on the dissociation effect of J / Ψ is similar. Finally, we investigate the influence of electric field and demonstrate that it also speeds up the J / Ψ dissociation. [ABSTRACT FROM AUTHOR]

We study the rotation effects of the hot and dense QCD matter in a non-perturbative regime by the gauge/gravity duality. We use the gravitational model that is designated to match the state-of-the-art lattice data on the thermal properties of (2+1)-flavor QCD and predict the location of the critical endpoint and the first-order phase transition line at large baryon chemical potential without rotation. After introducing the angular velocity via a local Lorentz boost, we investigate the thermodynamic quantities for the system under rotation in a self-consistent way. We find that the critical temperature and baryon chemical potential associated with the QCD phase transition decrease as the angular velocity increases. Moreover, some interesting phenomena are observed near the critical endpoint. We then construct the 3-dimensional phase diagram of the QCD matter in terms of temperature, baryon chemical potential, and angular velocity. As a parallel investigation, we also consider the gravitational model of SU(3) pure gluon system, for which the 2-dimensional phase diagram associated with temperature and angular velocity has been predicted. The corresponding thermodynamic quantities with rotation are investigated. [ABSTRACT FROM AUTHOR]

By using gauge/gravity duality, we calculate the spectral function of the heavy vector mesons with the presence of an intense magnetic field in a hot and dense medium. The results show that, a general conclusion, as the increases of magnetic field, chemical potential and temperature, the height of the peak of the spectral function decreases and the width increases. A nontrivial result is the change from the peak position of spectral function. We explain this non-trivial behavior by the interplay of the interaction between the two heavy quarks and the interaction between the medium with each of the heavy quarks. [ABSTRACT FROM AUTHOR]

The aerodynamic characteristics of flapping rotary wings (FRWs) have received considerable attention in design. In this study, optimizations of aerodynamic performance and kinematics of FRWs over the parameter space are explored. A well-validated Quasi-Steady model is employed to estimate the aerodynamic characteristics of FRWs in hovering flight, and a genetic algorithm is utilized for optimizing. It is assumed that flapping and pitching motion are given by motion parameters actively, while rotation is produced passively. Our results show that the optimal kinematic parameters are independent of flapping frequencies. The maximum lift comes from the high rotational speed caused by the small pitching amplitude, and the maximum power factor is from the large pitching amplitude. The dimensionless optimization of the flapping velocity as reference velocity is comparable to the dimensional results. The optimization model proposed in this study can be applied to the actual model for qualitative analysis. Rotational equilibrium power factor can reach more than 80% of the maximum value without rotation equilibrium constraint, but which rotational status can achieve the maximum power factor depends on the pitching angle at the mid-downstroke (αd). This study is helpful for the kinematic parameter design and further research of FRWs. [ABSTRACT FROM AUTHOR]

Understanding the variations of the westerly jets (WJs) during the Last Interglacial (~ 127 ka; LIG) aids in deciphering the reconstructed hydrological conditions and dust activities at that time. Here, we investigated variations of the WJs over the Northern Hemisphere during the LIG based on the Paleoclimate Modelling Intercomparison Project 4. We demonstrated that WJs exhibited divergent responses across regions and seasons during the LIG. In summer, WJs over the African–Asian–Pacific regions moved poleward by ~ 5° and weakened by 19% during the LIG, whereas there was only a slight change (+ 1°/− 2%) over the North American–Atlantic regions. In contrast, the winter WJs over the North American–Atlantic regions shifted poleward by ~ 2° and weakened by 7%, but with no obvious responses (− 0.2°/− 0.8%) over the African–Asian–Pacific regions. The WJs variations were linked to changes in meridional temperature gradients and maximum eddy growth rates. Furthermore, the poleward shift and weakening of the WJs over the East Asian–Pacific regions in summer resulted from the anomalous anticyclone triggered by the deep warm center over East Siberia and the anomalous cyclone linked with diabatic cooling over the western tropical Pacific. For the poleward-displaced and depressed WJs over the North American–Atlantic regions in winter, the propagation of Rossby waves from the eastern Pacific played a more important role, compared with the effect of tropical heating. Our work highlights divergent responses of the WJs to orbital forcing during the LIG, which helps to decipher the reconstructed westerlies-related processes and hence to obtain a better understanding of the climate change during this orbitally induced warm period. [ABSTRACT FROM AUTHOR]

Strain W712T was isolated from rhizosphere soil of Nicotiana tabacum L. collected from Kunming, south-west China. Cells were Gram-staining negative, aerobic, motile and rod shaped. The isolate grew at 20–45 °C (optimum 30 °C), pH 6.0–8.0 (optimum pH 7.0) and in the presence of up to 3.0% (w/v) NaCl (optimum 1%, w/v). Ubiquinone-10 was the only respiratory quinone type. Polar lipids contained diphosphatidylglycerol, phosphatidylmehtylethanolamine, phosphatidylglycerol, phosphatidylcholine and an unidentified aminolipid. The major fatty acids were detected as summed feature 8 (C18:1 ω7c or C18:1 ω6c), summed feature 3 (C16:1 ω7c or C16:1 ω6c) and C18:1 2OH. The genomic DNA G + C content was 68.7%. The ANI values were 94.3%, 93.3% and 93.6% between Azospirillum baldaniorum Sp245T, Azospirillum brasilense ATCC 49958T, Azospirillum formosense CC-Nfb-7T and strain W712T, respectively, which were lower than the prokaryotic species delineation threshold of 95.0–96.0%. The digital DNA–DNA hybridization values between A. baldaniorum Sp245T, A. brasilense ATCC 49958T, A. formosense CC-Nfb-7T and strain W712T indicated that the candidate represents a novel genomic species. According to the phenotypic and genotypic characteristics, we propose that strain W712T warrants the assignment to a novel species, for which the name Azospirillum tabaci sp. nov. (type strain W712T = CGMCC 1.18567T = KCTC 82186T) is proposed. [ABSTRACT FROM AUTHOR]

This work analyzes the free vibration of a spinning functionally graded graphene platelet-reinforced metal foam (FG-GPLRMF) beam. The differential transformation method is extended to analyze flap-wise bending vibration and chordwise bending vibration with Coriolis force effect for the first time. The beam is modeled using the Euler–Bernoulli beam theory. The Halpin–Tsai micromechanics model is utilized to predict effective material properties. Various types of graphene platelet (GPL) and porosity distributions are considered. The governing equations and corresponding boundary conditions of the FG-GPLRMF beam are obtained via Hamilton's principle. Results show that the vibration characteristics of the FG-GPLRMF beam are affected by the GPL geometry size, types of porosity, and GPL distributions. Among different types of porosity, the Porosity-A causes the highest fundamental natural frequency, while the Porosity-B corresponds to the lowest one of the spinning FG-GPLRMF beam in most cases. Moreover, the GPL pattern and porosity distribution have a coupled effect on the bending vibration of the spinning FG-GPLRMF beam. [ABSTRACT FROM AUTHOR]

An axion insulator is theoretically introduced to harbor unique surface states with half-integer Chern number C . Recently, experimental progress has been made in different candidate systems, while a unique Hall response to directly reflect the half-integer Chern number is still lacking to distinguish an axion state from other possible insulators. Here we show that the C = 1 2 axion state corresponds to a topological state with Chern number N = 1 in the Majorana basis. In proximity to an s − wave superconductor, a topological phase transition to an N = 0 phase takes place at critical superconducting pairing strength. Our theoretical analysis shows that a chiral Majorana hinge mode emerges at the boundary of N = 1 and N = 0 regions on the surface of an axion insulator. Furthermore, we propose a half-integer quantized thermal Hall conductance via a thermal transport measurement, which is a signature of the gapless chiral Majorana mode and thus confirms the C = 1 2 (N = 1 ) topological nature of an axion state. Our proposals help to theoretically comprehend and experimentally identify the axion insulator and may benefit the research of topological quantum computation. In topological condensed-matter systems, axion insulators are elusive excitation and active research in running to spot their signature. In this work, the authors theoretically propose a picture to characterize the surface of axion insulators and a possible detection scheme for thermal transport experiments with a precisely half-quantized outcome. [ABSTRACT FROM AUTHOR]

For a non-empty set X denote the full transformation semigroup on X by T(X) and suppose that σ is an equivalence relation on X. For every f ∈ T (X) , the kernel of f is defined to be ker f = { (x , y) ∈ X × X ∣ f (x) = f (y) } . Evidently, E (X , σ) = { f ∈ T (X) ∣ σ ⊆ ker f } is a subsemigroup of T(X). Also, the subset R E (X , σ) of E (X , σ) consisting of regular elements is a subsemigroup. Partition of a semigroup by Green's ∗ -relations was first introduced by Fountain in 1979 and the Green's ∼ -relations (with respect to a non-empty subset U of the set of idempotents) as a new method of partition were introduced by Lawson (J Algebra 141(2):422–462, 1991). In this paper, we intend to present certain characterizations of these two sets of Green's relations of the semigroup E (X , σ) . This investigation proves that the semigroup E (X , σ) is always a right Ehresmann semigroup. Finally, we prove that R E (X , σ) is an orthodox semigroup if and only if the set X consists of at most two σ -classes. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the efficacy of fronto-orbit reconstruction surgery on pediatric metopic synostosis via an image-based 3D reconstruction in Chinese population. Methods: Thirty pediatric metopic synostosis patients who received fronto-orbital reconstruction surgery in the Children's Hospital of Nanjing Medical University, Department of Neurosurgery, from January 2007 to December 2018 were analyzed in the study. Here we use the Mimics 20.0 software to reconstruct patients' cranial thin-section CT scan images from pre- and post-operation and control groups. Then the data of intracranial volume, frontal volume, orbital hypertelorism, ECA, ZF, and ORA were analyzed using the paired t-test or Wilcoxon matched-pairs signed-ranks test. Results: The age of these patients was 15.83 ± 16.12 months. After surgery, the mean frontal volume was enlarged from 92.75 ± 26.97 to 138.62 ± 47.97 cm3 (P < 0.0001), and the intracranial volume was enhanced from 976.87 ± 230.83 to 1059.44 ± 217.98 cm3 (P < 0.0001). In the meantime, the ECA was changed from 108.02 ± 8.17 to 134 ± 5.59° (P < 0.0001). In line with the alteration of the parameters mentioned above, the head shapes in all patients were also significantly improved after the surgery with no obvious complications. Conclusion: Fronto-orbit reconstruction surgery is a safe and effective treatment for pediatric metopic synostosis. Computer-aided 3D reconstruction could serve as a quantitative strategy to evaluate the efficacy of craniofacial surgery. [ABSTRACT FROM AUTHOR]

Interleukin (IL)-35, which has an anti-inflammatory role in acute respiratory distress syndrome (ARDS)/acute lung injury (ALI), is relatively promising as a drug target. Studies have shown that curcumin may play a therapeutic role in ALI and enhance the suppressive function of regulatory T cells (Tregs). To illustrate the effect of curcumin on the regulation of Treg cell differentiation and expression of IL-35, we built a cecal ligation and puncture (CLP)–induced acute lung injury mouse mode with curcumin pretreatment. The expression of IL-35 in serum, severity of lung injury, IL-17A in lung tissue, survival rate, Treg-related cytokines levels in serum, nuclear factor-kappa B (NF-κB)'s nuclear translocation in lung tissue, and splenic CD4+CD25+FOXP3+ Tregs were assessed. Furthermore, the proportion of Tregs, STAT5, and IL-35 expression during naïve CD4+ T cell differentiation in vitro was measured. Compared with the CLP group, the increased IL-35 expression in CLP with the curcumin pretreatment (CLP + Cur) group was consistent with the decreased severity of lung injury, IL-17A protein levels in lung tissue, and Treg-related cytokines levels. Pretreatment with curcumin, the survival rate climbed to 50%, while the mortality rate was 100% in the CLP group. In addition, splenic CD4+CD25+FOXP3+ Treg cells increased in the CLP + Cur group. In vitro, CD4+CD25+FOXP3+ Treg cells from naïve CD4+ T cells, STAT5 proportion, and IL-35 expression increased after curcumin treatment. These findings showed that curcumin might regulate IL-35 by activating the differentiation of Treg cells to control the inflammation in acute lung injury. [ABSTRACT FROM AUTHOR]

A series of novel quinolinyl imidazolidin-2-imine nickel complexes with different substituents on the imidazolidin-2-imine ligand were synthesized and characterized. The complexes in the presence of methylaluminoxane (MAO) as a cocatalyst catalyzed the copolymerization of norbornene (N) and styrene (S) or para-chlorostyrene (CS) with high activity (up to 1070 kg·mol−1·h−1). The installation of sterically bulky substituents on the imidazolidine-2-imine ligand was effective for the increase of the molecular weight and the comonomer content, affording high molecular weight copolymers with tunable CS content (0.57 mol%–11.7 mol%), in which the existence of Cl group can provide reaction site for the further functionalization of copolymers as well as the synthesis of graft or cross-linked polymers. The linear relationship between the comonomer content and the glass transition temperature of the copolymers and the monomer reactivity ratios in the copolymerization indicated the formation of the expected functionalized cyclic olefin copolymers (COC). [ABSTRACT FROM AUTHOR]

Dear Sir, In early December 2019, a severe acute respiratory infection was firstly reported in Wuhan and then recognized as coronavirus disease 2019 (COVID-19). In response to the WHO statements and international concerns regarding the COVID-19 outbreak, the Chinese Society of Nuclear Medicine (CSNM) promptly put forward a consensus on the management of nuclear medical care (NM care) during the COVID-19 epidemic [[7]]. Retrospective NM findings of COVID-19 In retrospective studies, Qin et al. [[13]] and Zou et al. [[14]] have reported the SP 18 sp F-FDG PET/CT findings in COVID-19 patients. [Extracted from the article]

It is very significant to improve the diameter accuracy of micro-shafts fabricated by micro-electrical discharge machining (micro-EDM) in micro-tools application. The diameter accuracy includes the uniformity of a single micro-shaft in axial direction and the repeatability of micro-shafts with the same diameter. A newly proposed method, named twin-mirroring-wire tangential feed electrical discharge grinding (TMTF-WEDG), can realize high uniformity and repeatability of micro-shafts via tangentially feeding and constraining of a narrow slit formed by a twin-mirroring-wire on the diameter of micro-shafts, respectively. Controlling the material removal thickness in single-step machining of micro-shafts is necessary to achieve high uniformity and repeatability. This paper focuses on the effects of the several important factors on the material removal thickness of micro-shafts to reveal the effects on the diameter uniformity and repeatability, including the open voltage, capacitance, feed rate in the Z-direction, feed step in the Y-direction, and tangential feed distance. The results indicate that the lower open voltage or the smaller capacitance or higher Z-direction feed rate, the smaller the thickness of the material removed, which is advantageous for controlling the consistency and repeatability of the micro-shafts. Decreasing of Y-direction feed step from 20 to 5 μm is accompanied by a reduction in material removal thickness, and the material removal thickness of less than 0.4 μm is achieved with a smaller feed step of in the Y-direction. As the tangential feed distance S2 decreases, the material removal thickness of the micro-shafts decreases gradually. In this study, the uniformity and repeatability of brass and tungsten micro-shafts are controlled within 1 μm and 2 μm, respectively. [ABSTRACT FROM AUTHOR]

A bulk Poly(vinyl alcohol)/ZIF-8 (PVA/ZIF-8) porous composite with aligned porous structure was prepared by ice-templating method. The microstructure of PVA/ZIF-8 porous composites was characterized by scanning electron microscopy (SEM). The results showed that the composites had regular pore structure and ZIF-8 nanoparticles were evenly distributed on the skeleton of PVA. X-ray diffraction (XRD) test results showed that the crystalline structure of ZIF-8 was well preserved in the composites. The specific surface area of the composite was characterized by nitrogen adsorption/desorption test. The specific surface area of the composite was up to 1160 m2·gt1. PVA/ZIF-8 porous composites could also support a certain weight with almost no volume shrinkage. The carbon dioxide adsorption quantity of the composite was up to 11.3 cm3·gt1, proving that PVA/ZIF-8 porous composite has a good application prospect in the field of carbon dioxide adsorption. [ABSTRACT FROM AUTHOR]

Mitochondrial dysfunction is a hallmark of Alzheimer's disease (AD), which may be related to mitophagy failure. Previous reports suggest that treadmill exercise protects against mitochondrial dysfunction in AD. However, few studies have investigated the relationship between mitophagy and mitochondrial adaptation caused by treadmill exercise in AD. The current study aimed to investigate whether exercise-ameliorated AD is associated with changes in mitophagy activity. Both Wild-type and APP/PS1 transgenic mice were divided into sedentary (WTC and ADC) and exercise (WTE and ADE) groups (n = 9 for each group). WTE and ADE mice were subjected to treadmill exercise for 12 weeks, followed by evaluating the effect of treadmill exercise on learning and memory ability, Aβ plaques, mitochondrial Aβ peptide level, synaptic activity and mitochondrial function. Meanwhile, mitophagy-related proteins PINK1, Parkin, LC3II and P62 were measured in the hippocampal mitochondrial fractions. The results indicated that exercise not only restored learning and memory ability, but also reduced Aβ plaque area, mitochondrial Aβ peptide level, and increased levels of synaptic markers SYN and GAP43, as well as reversed mitochondrial dysfunction (defective mitochondrial ultrastructure, decreased PGC-1α, TFAM and ATP levels) in APP/PS1 transgenic mice. Moreover, exercise increased mitophagy activity as evidenced by a significant decrease in levels of P62 and PINK1 as well as an increase in levels of LC3II and Parkin in ADE mice. These findings suggest that treadmill exercise can enhance mitophagy activity in the hippocampus, which is efficient in ameliorating pathological phenotypes of APP/PS1 transgenic mice. [ABSTRACT FROM AUTHOR]

By the use of the gauge/gravity duality, we calculate the imaginary part of heavy quarkonium potential and thermal width with the effect of gluon condensate which is absent in AdS 5 background. Our results show that the dropping gluon condensate reduces the absolute value of imaginary potential and therefore decreases the thermal width both in "exact" and "approximate" approach implying that the heavy quarkonium has a weaker bound with the increase of gluon condensate. In addition, the thermal width will disappear at a critical condensate value, which indicates the dissociation of quarkonium. We conclude that increasing gluon condensate will lead to easier dissociation of heavy quarkonium for fixed temperature. [ABSTRACT FROM AUTHOR]

Background: Although robotic surgery is popular around the world, its safety and efficacy over classical open surgery is still controversial. The purpose of this article is to compare the safety and efficacy of robotic pancreaticoduodenectomy (RPD) and open pancreaticoduodenectomy (OPD).Methods: A literature search of PubMed, Web of Science, and the Cochrane Library database up to July 29, 2018 was performed and the meta-analysis was performed using RevMan 5.2 software with Fixed and random effects models applied. The IRB approval and written consent were not needed for this paper.Results: Twelve non-randomized retrospective studies and 1 non-randomized prospective study consisting of 2403 patients were included in this meta-analysis. There were 788 (33%) patients in the RPD group and 1615 (67%) patients in the OPD group. Although RPD was associated with a longer operative time (weighted mean difference [WMD]: 71.74 min; 95% CI 23.37-120.12; p = 0.004), patient might benefit from less blood loss (WMD: - 374.03 ml; 95% CI - 506.84 to - 241.21; p < 0.00001), shorter length of stay (WMD: - 5.19 day; 95% CI - 8.42 to - 1.97; p = 0.002), and lower wound infection rate (odds ratio: 0.17; 95% CI 0.04-0.80; p = 0.02). No statistically significant difference was observed in positive margin rate, lymph nodes harvested, postoperative complications, reoperation or readmission rate, and mortality rate.Conclusions: Robotic pancreaticoduodenectomy is a safe and feasible alternative to open pancreaticoduodenectomy with regard to short-term outcomes. Further studies on the long-term outcomes of these surgical techniques are needed. [ABSTRACT FROM AUTHOR]

In this paper, free vibration of a metal foam core sandwich (MFCS) beam embedded in Winkler–Pasternak elastic foundation is studied using the Chebyshev collocation method (CCM). This method can achieve high precision within the range allowed by the effective number of bits of computers. Three foam distribution types along the thickness direction are considered for the core. The Timoshenko beam theory is adopted and Hamilton's principle is utilized to derive the boundary conditions and governing equations of the model. The numerical results show that natural frequencies of the sandwich beam initially increase and then decrease with the rise in thickness of metal foam core. By arranging the foam distribution in the core, natural frequencies of the sandwich beam can be significantly changed. Moreover, natural frequencies of the uniform foam distribution beam are insensitive to the foam coefficient. For the beam with non-uniform foam distribution, however, the natural frequencies increase or decrease with the foam coefficient, depending closely on the foam type. In addition, the present method is validated by comparing with the published ones for special cases. [ABSTRACT FROM AUTHOR]

In this paper, free vibrations of cylindrical nanoshells made of nanoporous metal foam are investigated for the first time. Based on the modified couple stress theory and Love's thin shell theory, the governing equations of the present system are derived by using Hamilton's principle. Two types of nanoporosity distribution are considered in the construction of the nanoporous shells. Then, the Navier method and Galerkin method are utilized to solve natural frequencies of the nanoporous shells under different boundary conditions. Afterwards, a detailed parametric study is conducted. Results show that the nanoporosity type, the material length scale parameter, the porosity coefficient, the length-to-radius ratio, and the radius-to-thickness ratio play important role on the free vibrations of nanoporous shells. To check the validity of the present analysis, the results are compared with those in previous studies for the special cases. [ABSTRACT FROM AUTHOR]

An interpenetrating double network hydrogel based on cellulose backbone and poly-dopamine dendritic structure was successfully prepared with the advantages of controlled hydrophobic drug loading, pH-responsive ability, and long-term bacteriostatic property. 13C-NMR was used to process the structural characterization and explain the mechanism of hydrogel system's construction. Hydrophobic drug of ciprofloxacin with carbonyl group can evenly carry in the hydrogel system, and the highest loaded ratio of ciprofloxacin was reach to 80.56%. Besides, the swelling property and the controlled drug loading ability of our prepared hydrogel were carefully studied, which showed a close relation with the hydrogel design. Moreover, the in vitro drug release experiments demonstrated that the hydrogel had an obvious pH-responsive release property of ciprofloxacin, and the result of bacteriostatic experiment also showed a long-term bacteriostatic effect on Escherichia coli, which showed potential application on biological and medical fields, including wound treatment. Graphical abstract. [ABSTRACT FROM AUTHOR]

The purpose of the current study was to examine the mediating roles of parent-child communication and parental warmth in the relationship between economic pressure and loneliness in a sample of migrant children in China. A total of 437 participants were selected from two public schools for migrant children in Zhejiang Province, China. All participants were asked to complete four measures, including the Perceived Economic Strain Scale, the Parent-Child Communication Questionnaire, the Parental Warmth Scale, and the Children's Loneliness Scale. The results showed that economic pressure was positively and directly related to loneliness. Furthermore, parent-child communication and parental warmth partially mediated the relationship between economic pressure and loneliness in migrant children. Thus, parent-child communication and parental warmth play important roles in reducing the negative effect of economic pressure on loneliness in migrant children. [ABSTRACT FROM AUTHOR]

It has demonstrated that there are major advantages and synergistic effects on flame retardancy in using a combination of borates with magnesium hydroxide. In this paper, a novel 2MgO·B2O3·1.5H2O-Mg(OH)2 nanocomposite has been controllably prepared by in situ hydrothermal reaction, and the formation mechanism of the nanocomposite was proposed. As a comparison, 2MgO·B2O3·1.5H2O nanobelt and Mg(OH)2 nanosheet were also prepared. All samples were characterized by XRD, FT-IR, TG, SEM, TEM and HRTEM. Furthermore, their flame-retardant properties were investigated by thermal analysis method and oxygen index method, demonstrating that the flame retardancy of nanocomposite is significantly higher than that of single 2MgO·B2O3·1.5H2O or Mg(OH)2. The possible flame retarding mechanism has been proposed. It can be predicted that this nanocomposite could serve as a potential flame retardant. [ABSTRACT FROM AUTHOR]

Two new isocoumarins, (3R)-methyl-8-hydroxy-6-(hydroxymethyl)-7-methoxydihydroisocoumarin (1) and (3R)-methyl-7,8-dimethoxy-6-(hydroxymethyl)dihydroisocoumarin (2), together with three known isocoumarins (3-5), were isolated from the fermentation products of an endophytic fungus Aspergillus versicolor. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. The anti-tobacco mosaic virus (anti-TMV) activities of compounds 1 and 2 were evaluated. Compounds 1 and 2 showed anti-TMV activities with inhibition rates of 21.8 and 18.6% at the concentration of 20 μM, respectively. [ABSTRACT FROM AUTHOR]

To understand the behaviors of tropical cyclones (TCs), it is very important to explore how TCs respond to anthropogenic greenhouse gases and natural forcings. Volcanic eruptions are a major natural forcing mechanism because they inject sulphate aerosols into the stratosphere, which modulate the global climate by absorbing and scattering solar radiation. The number of Atlantic hurricanes is thought to be reduced following strong tropical eruptions, but whether the response of TCs varies with the locations of the volcanoes and the different ocean basins remains unknown. Here, we use the Community Earth System Model-Last Millennium Ensemble to investigate the response of the large-scale environmental factors that spawn TCs to strong volcanic eruptions at different latitudes. A composite analysis indicates that tropical and northern hemisphere volcanic eruptions lead to significantly unfavorable conditions for TC genesis over the whole Pacific basin and the North Atlantic during the 3 years post-eruption, relative to the preceding 3 years. Southern hemisphere volcanic eruptions result in obviously unfavorable conditions for TC formation over the southwestern Pacific, but more favorable conditions over the North Atlantic. The mean response over the Indian Ocean is generally muted and insignificant. It should be noted that volcanic eruptions impact on environmental conditions through both the direct effect (i.e. on radiative forcing) and the indirect effect (i.e. on El Niño-Southern Oscillation), which is not differentiated in this study. In addition, the spread of the TC genesis response is considerably large for each category of eruptions over each ocean basin, which is also seen in the observational/proxy-based records. This large spread is attributed to the differences in stratospheric aerosol distributions, initial states and eruption intensities, and makes the short-term forecast of TC activity following the next large eruption challenging. [ABSTRACT FROM AUTHOR]

Investigation of past tropical cyclone (TC) activity in the Western North Pacific (WNP) is potentially helpful to enable better understanding of future TC behaviors. In this study, we examine variations in large-scale environmental factors important to TC genesis in the last millennium simulations from the Paleoclimate Modelling Intercomparison Project Phase 3 (PMIP3). The results show that potential intensity, a theoretical prediction of the maximum TC intensity, is increased relative to the last millennium in the north part of the WNP in the Medieval Climate Anomaly (MCA; 950-1200 AD) while it is decreased in the Little Ice Age (LIA; 1600-1850 AD). Vertical wind shear that generally inhibits TC genesis is enhanced (reduced) to the south of 20°N and is reduced (enhanced) to the north in the MCA (LIA). Relative humidity (at 600 hPa) that measures the mid-tropospheric moisture content broadly shows an increase (decrease) in the MCA (LIA). A genesis potential index indicates that conditions are generally favorable (unfavorable) for TC formation in the WNP in the MCA (LIA), especially in the northern part. Taking changes in steering flows into account, there may be an increasing (decreasing) favorability for storm strikes in East Asia in the MCA (LIA). The estimated TC activity is consistent with the geological proxies in Japan, but contradicts with the typhoon records in southern China and Taiwan. This model-data discrepancy is attributed to the limitations in both simulations and reconstructions. [ABSTRACT FROM AUTHOR]

Low-velocity drop-weight impact experiments on individual and multiple Cyclotetramethylene tetranitramine (HMX) energetic particles were performed using a modified drop-weight machine equipped with high-speed photography components. Multiple particles experienced more severe burning reactions than an individual particle. Comparisons between impacted salt and HMX particle show that jetting in HMX is mainly due to the motion of fragmented particles driven by gaseous reaction products. Velocity of jetting, flame propagation, and area expansion were measured via image processing, making it possible to quantify the chemical reaction or mechanical deformation violence at different stages. [ABSTRACT FROM AUTHOR]

The motional consensus of self-propelled particles is studied in both noise-free cases and cases with noise by the standard Vicsek model. In the absence of noise, we propose a simple method, using grid-based technique and defining the normalized variance of the ratio of the number of particles locally to globally, to quantitatively study the movement pattern of the system by the spatial distribution of the particles and the degree of aggregation of particles. It is found that the weaker correlation of velocity leads to larger degree of aggregation of the particles. In the cases with noise, we quantify the competition between velocity alignment and noise by considering the difference of the variety of order parameter result from the velocity alignment and noise. The variation of the effect of noise on motional consensus is non-monotonic for the change of the probability distribution of noise from uniform to non-uniform. Our results may be useful and encourage further efforts in exploring the basic principles of collective motion. [ABSTRACT FROM AUTHOR]

The title complex, {[Zn(ODIB)( bpdc)]·2DMF} was prepared under hydrothermal conditions (dimethylformamide and water) based on two ligands, namely, 1,1′-oxy-bis[3,5-diimidazolyl-benzene] (ODIB) and biphenyldicarboxylic acid (H bpdc). ODIB ligands link Zn cations to give layers in crystal. bpdc anions coordinate to Zn atoms, however, their introduction does not increase the dimension of the structure. Each layer is partially passes through the adjacent layers in the offset ABAB manner. [ABSTRACT FROM AUTHOR]

Testosterone deficiency is associated with a higher incidence of cardiovascular diseases in men. However, its effect on cell senescence, which plays a causal role in vascular aging, remains unclear. Here, we tested the hypothesis that testosterone alleviated vascular smooth muscle cell (VSMC) senescence and collagen synthesis via growth arrest-specific protein 6 (Gas6)/Axl- and Akt/FoxO1a-dependent pathways. Testosterone significantly ameliorated angiotensin II-induced VSMC senescence and collagen overexpression. In addition, testosterone inhibited angiotensin II-induced matrix metalloproteinase-2 (MMP-2) activity, which played a pivotal role in facilitating age-related collagen deposition. Testosterone increased the expression of tissue inhibitor of metalloproteinase-2 but decreased the expression of MMP-2 and membrane type-1 metalloproteinase which contributed to increase MMP-2 activity. The effects on VSMCs senescence and collagen synthesis were mediated by restoration of angiotensin II-induced downregulation of Gas6 and Axl expression and a subsequent reduction of Akt and FoxO1a phosphorylation. The effects of testosterone were reversed by a Gas6 blocker, Axl-Fc, and a specific inhibitor of Axl, R428. Treatment of VSMCs with PI3K inhibitor LY294002 abrogated the downregulating effect of testosterone on MMP-2 activity. Furthermore, when FoxO1a expression was silenced by using a specific siRNA, the inhibitory effect of testosterone on MMP-2 activity was revered as well, that indicated this process was Akt/FoxO1a dependence. Taken together, Gas6/Axl and Akt/FoxO1a were involved in protective effects of testosterone on VSMCs senescence and collagen synthesis. Our results provide a novel mechanism underlying the protective effect of testosterone on vascular aging and may serve as a theoretical basis for testosterone replacement therapy. [ABSTRACT FROM AUTHOR]

In this paper, the design, fabrication, and characterization of a robust and low-power micro-machined two-dimensional (2-D) wind sensor based on a glass-in-silicon reflow process are presented for the first time. The four thermistors, which act simultaneously as heat sources and as temperature sensors, are placed on a low thermal conductivity glass substrate, and arranged in a Wheatstone bridge configuration supplied with constant voltage. In this self-heated mode, the total power consumption of the sensor could be reduced into the sub-milliwatt range, offering high initial sensitivity and wide measurement range, respectively. The embedded vertical silicon vias in the glass substrate are used to realize the electrical connections between the sensing elements and the electrode-pads, which are respectively placed on the front and the back surface of the chip. Then, the sensor and the external circuit are connected using the wire-bonding process through the electrode-pads on the back surface. The bonding wires at the backside is encapsulated by polyester paint, protecting the electrical connections of the sensor from the effect of the external environment. In addition, a passivation layer of nitride is deposited on the surface of the wind sensor to prevent direct exposure of the sensing elements to harsh media. The sensor was tested in a wind tunnel in constant voltage mode. Measurement results show that the thermal wind sensor can measure wind speeds up to 17.5 m/s, and the measured sensitivities of the sensor with different applied voltages (0.5, 1, 1.5 V) are, respectively 24.9, 148.3 and 440.61 mV/(m/s) at zero-flow point. The corresponding power consumption of the sensor with different voltages are respectively 4.81, 19.23 and 43.27 mW. Measurement results also show that wind direction in a full range of 360° with an err within 6° could be obtained. The proposed sensor can be used for many applications with a low power consumption and high reliability. [ABSTRACT FROM AUTHOR]

A wide variety of 3-arylbenzo[ f]quinoline-1,2-dicarboxylates and their dehydro derivatives have been synthesized by one-pot, three-component reaction of an aromatic aldehyde, naphthalene-2-amine, and dimethyl but-2-ynedioate in the presence of SnCl under reflux in acetonitrile. This procedure has several advantages, for example high yield, short reaction time, easy work-up, little pollution, and low price of the catalyst. [ABSTRACT FROM AUTHOR]

In this paper, novel, very simple and low-cost thin film position sensitive detectors (TFPSDs) which employ indium tin oxide (ITO)-cadmium sulfide (CdS)-Au structures are presented. Different from the existed PSDs those based on lateral photovoltage effect, the proposed sensor is operated in principle of photoconductive effect. CdS film is chosen as the photosensitive layer since its excellent photoconductive property, low cost and suitable for depositing on different type substrates with large areas. In the present study, CdS films are deposited on silicon substrates by using rf magnetron sputtering at room temperature. After that, the prepared CdS films were annealed at different temperatures for 50 min in N ambient and a rigorous analysis was presented on the surface topography, and photoconductive properties by scanning electron microscopy and semiconductor characteristics analyzer. The test results shows that the film annealed at 400 °C has the best photoconductive property. Moreover, the finite-element method was used to study the relationship between the Aluminium (Al) electrode shape and the linearity of PSD. Three different type PSDs (quadrilateral, rectangular-shaped and pillow-shaped) were designed and simulated. The simulation results indicate that the quadrilateral electrode is suitable for large-area PSDs, whereas the rectangular-shaped and pillow-shaped electrodes can be used to realize small-area PSDs. The measurement results shows that the non-linearities of three type PSDs with dimensions of 10 × 10 mm are respectively 2.106, 3.594, and 3.55 %, which verify the conclusion deduced from the simulation results. [ABSTRACT FROM AUTHOR]

The key mechanism which enables two-qubit operations of a hybrid quantum processing unit for hybrid quantum computing is demonstrated. A scheme which realizes a disguised switch for two-qubit gating is proposed, combining external magnetic field control, quantum dot sample tuning, and assisted laser control. Our methods overcome the limitation of asynchrony between single-qubit operations of respective solid-state qubits and improve the efficiency of single-qubit gating. [ABSTRACT FROM AUTHOR]

Nanomagnetic materials offer exciting avenues for advancing cancer therapies. Most researches have focused on efficient delivery of drugs in the body by incorporating various drug molecules onto the surface of nanomagnetic particles. The challenge is how to synthesize low toxic nanocarriers with multi-target drug loading. The cancer cell death mechanisms associated with those nanocarriers remain unclear either. Following the cell biology mechanisms, we develop a liquid photo-immobilization approach to attach doxorubicin, folic acid, tumor necrosis factor-α and interferon-γ onto the oleic acid molecules coated Fe3O4 magnetic nanoparticles to prepare a kind of novel inner/outer controlled multi-target magnetic nanoparticle drug carrier. In this work, this approach is demonstrated by a variety of structural and biomedical characterizations, addressing the anti-cancer effects in vivo and in vitro on the HeLa and it is highly efficient and powerful in treating cancer cells in a valuable programmed cell death mechanism for overcoming drug resistance. [ABSTRACT FROM AUTHOR]

In this paper, the global diffeomorphism theorem due to Zampieri was generalized. The concept of the basin of attraction is the main tool of our exposition in discussing the diffeomorphism between Banach spaces. The existence and uniqueness of a solution of the fourth order elliptic boundary value problem was proved by employing our generalized theorem. The results of this paper generalize some known theorems. [ABSTRACT FROM AUTHOR]

Two new anthraquinones, siameaquinones A ( 1) and B ( 2), together with seven known anthraquinones ( 3-9), were isolated from the stems of Cassia siamea. The structure of 1-9 was elucidated by spectroscopic methods, including extensive D and D NMR techniques. Compounds 1 and 2 were also evaluated for their cytotoxicities against five human tumor cell lines. The results revealed that compound 1 showed moderate cytotoxicities against A549 and SHSY5Y cells with IC values of 5.2 and 6.3 μM, and compound 2 showed moderate cytotoxicities against NB4 and SHSY5Y cells with IC values of 8.8 and 7.5 μM, respectively. [ABSTRACT FROM AUTHOR]

In this paper, a new sufficient condition of the existence and uniqueness of the second order elliptic boundary value problem is given by using the basin of attraction. Some known existent results on the existence of solutions of the nonlinear elliptic equation are generalized. [ABSTRACT FROM AUTHOR]

In microelectrical discharge machining (μEDM), the machining repeatability of microshafts with the same diameter is low due to the complex and stochastic nature of sparking. To improve machining repeatability, the effects of the main error sources on diameter accuracy of microshafts fabricated by wire electrical discharge grinding (WEDG) were analyzed. Strategies to minimize diameter differences between the target microshaft and the microshaft finally obtained by semifinishing and finishing were then proposed. Determining an appropriate infeed (depth of a cut) according to the desired erosion depth in the radial direction (Δ R) of microshafts was chosen as the control strategy for the semifinishing of microshafts produced by WEDG. To determine the infeed, empirical models that evaluate the relationship between the infeed and Δ R were developed through a large number of experiments. For the finishing of microshafts using WEDG, machining strategies such as zero infeed and stopping the wire electrode running, were proposed to eliminate some of the inherent errors. Finally, the empirical models developed for determining the infeed were verified by the successful fabrication of a stepped microshaft, which has small deviations from its desired diameters. By employing the developed empirical models and machining strategies, diameters of 26 out of 28 microshafts fabricated were found to lie in the range of 45 ± 2 μm. The experimental results verify that the diameter control strategies are effective and can be used to improve machining repeatability. [ABSTRACT FROM AUTHOR]

Postoperative sore throat (POST) is one of the main postoperative complaints. This study was to evaluate the efficacy of budesonide inhalation suspension (BIS) in reducing the incidence and severity of POST. One hundred and twenty patients scheduled for thyroid surgery with general anesthesia were enrolled and randomized into three groups. Group A received 200 mcg BIS 10 min prior to the tracheal intubation and received the same treatment 6 and 24 h after extubation. Group B received 200 mcg BIS 6 and 24 h after extubation. Control group received the same scheduled treatment as Group A, but the BIS was replaced with 2 ml normal saline. The patients were evaluated for sore throat and hoarseness 1, 24 and 48 h after extubation. The status of laryngopharynx was also recorded. There was no statistically significant difference in the incidence of sore throat among three groups. However, hoarseness occurred significantly less frequently in Group A ( P < 0.05). One hour after extubation, Group A exhibited significantly less severe sore throat and hoarseness compared to the other two groups ( P < 0.05), which disappeared 24 h later. The mucositis scores of laryngopharynx at 1, 24 and 48 h post-extubation were significantly lower in Group A ( P < 0.05). BIS can reduce the incidence and severity of the POST prophylactically. [ABSTRACT FROM AUTHOR]

One of the key uncertainties in future sea-level projections is attributed to the Greenland ice sheet (GrIS). Studying the response of the GrIS to climate changes during the past warm periods is helpful for understanding future changes in the GrIS. In this study, using three global climate models (Community Atmosphere Model version 3.1 and version 4.0 and Norwegian Earth System Model) and a three-dimensional ice sheet model, we investigate the climate and ice sheet changes over Greenland during the mid-Pliocene warm period (~3 Ma bp). The results show that the regionally averaged summer temperature over Greenland is 9.4-13.4 °C higher during the mid-Pliocene period than during the pre-industrial era and the annual mean precipitation is 65.2-108.3 mm a greater. In response to this warm-wet climate, the GrIS shows a substantial decrease in size during the mid-Pliocene, with little ice existing along the eastern coast of Greenland. Compared to that simulated in the control run, the global sea level is approximately 7.8-8.1 m higher during the mid-Pliocene due to the decrease in the size of the GrIS. In addition, paleoclimate proxies also indicate that it is unlikely that a large-scale ice sheet exists over Greenland during the mid-Pliocene warm period. [ABSTRACT FROM AUTHOR]

Sea level rise (SLR) is one of the major socioeconomic risks associated with global warming. Mass losses from the Greenland ice sheet (GrIS) will be partially responsible for future SLR, although there are large uncertainties in modeled climate and ice sheet behavior. We used the ice sheet model SICOPOLIS (SImulation COde for POLythermal Ice Sheets) driven by climate projections from 20 models in the fifth phase of the Coupled Model Intercomparison Project (CMIP5) to estimate the GrIS contribution to global SLR. Based on the outputs of the 20 models, it is estimated that the GrIS will contribute 0-16 (0-27) cm to global SLR by 2100 under the Representative Concentration Pathways (RCP) 4.5 (RCP 8.5) scenarios. The projected SLR increases further to 7-22 (7-33) cm with 2×basal sliding included. In response to the results of the multimodel ensemble mean, the ice sheet model projects a global SLR of 3 cm and 7 cm (10 cm and 13 cm with 2×basal sliding) under the RCP 4.5 and RCP 8.5 scenarios, respectively. In addition, our results suggest that the uncertainty in future sea level projection caused by the large spread in climate projections could be reduced with model-evaluation and the selective use of model outputs. [ABSTRACT FROM AUTHOR]

The Huisgen reaction has been used to synthesize five-membered heterocyclic compounds in high yield and with high regio and stereoselectivity. In the synthesis of spiro [pyrrolidine-2,3′-oxindole] derivatives from isatin, α-amino acids, and ( E)-β-phenyl nitroolefins, two regioisomers were obtained in each reaction. The regioselectivity of the major product was found to be different from that in reported work, and was investigated at the B3LYP/6-311G* level of theory. On the basis of this new finding, several conditions, for example molar ratio, solvent, and temperature, which affect the regioselectivity of this reaction were investigated; the results obtained are discussed. It was found that the regioselectivity of this reaction was affected by solvent and temperature, irrespective of the ratio of the reactants. Low temperature and high solvent polarity leads to high regioselectivity, and protic solvents result in higher yield and regioselectivity. These results are of benefit for regioselective synthesis of some compounds. [ABSTRACT FROM AUTHOR]

Novel imidazo[1,5-a]pyridinyl 1,3,4-Oxadiazole derivatives were synthesized and characterised by IR, H NMR and HRMS.UV-vis absorption and fluorescence properties of these compounds in different solutions showed that the maximal emission wavelength was not significantly changed in different solvents; however, maximum absorption wavelength was blue-shifted with the increase of solvent polarity. Absorption λ and emission λ was less correlated with substituent groups on benzene rings. The calculated molecular orbital correlates well with their absorption. [ABSTRACT FROM AUTHOR]