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Jibo Han,* Xiaowen Shi,* Zhanxiong Zheng, Bin Zhang, Fengjie Shi, Liqin Jiang, Jianjiang Xu Department of Cardiology, Second Affiliated Hospital of Jiaxing University, Jiaxing, Zhejiang 314000, China *These authors contributed equally to this work Introduction: Schisandrin B (SchB), the main active constituent in Schisandra chinensis, has antioxidant activities. Endothelial dysfunction leads to various cardiovascular diseases. Oxidative stress is a crucial pathophysiological mechanism underpinning endothelial dysfunction.Methods: We elucidated the role and underlying mechanisms of SchB in angiotensin II-induced rat aortic endothelial-cell deficits and explored targets of SchB through siRNA analysis and molecular docking. We measured apoptosis by TUNEL and oxidative stress by dihydroethidium (DHE) and 2’,7’ –dichlorofluorescin diacetate (DCF) staining.Results: Our results demonstrated that SchB significantly ameliorated oxidative stress, mitochondrial membrane-potential depolarization and apoptosis in angiotensin II-challenged rat aortic endothelial cells. We further discovered that these antioxidative effects of SchB were mediated through induction of Nrf2. Importantly, using molecular docking and molecular dynamic simulation, we identified that Keap1, an adaptor for the degradation of Nrf2, was a target of SchB.Conclusion: These findings support the potential use of SchB as a Keap1 inhibitor for attenuating oxidative stress, and Keap1 might serve as a therapeutic target in the treatment of cardiovascular diseases. Keywords: schisandrin B, Keap1, oxidative stress, angiotensin II, rat aortic endothelial cell

BACKGROUND Epidermal growth factor receptor (EGFR) expression is associated with hepatic fibrogenesis. Activated hepatic stellate cells (HSCs) release inflammatory cytokines and extracellular matrix (ECM). The aim of this in vitro study was to investigate HSCs, activated by lipopolysaccharide (LPS), and the role of EGFR using the small molecule EGFR inhibitor, AG1478, and using knockdown of the EGFR gene using small interfering RNA (siRNA) cell transfection. MATERIAL AND METHODS HSCs, isolated from male Sprague-Dawley rats, were cultured and treated with and without LPS (100 ng/mL), with and without AG1478 (2.5 μM and 5.0 μM) Cell survival and proliferation were studied using an MTT assay. Western blot was used to measure levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IκBα, cytoplasm and nuclear NFκB and EGFR in the cell lysates before and after small interfering RNA (siRNA) transfection. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) was used to measure the mRNA levels of transforming growth factor (TGF)-β, Col-1, and α-smooth muscle actin (SMA). The Toll-like receptor 4 (TLR4) antagonist TAK-242 and the selective c-Src inhibitor, PP2 in LPS induced-EGFR phosphorylation was evaluated using Western blot. RESULTS Inhibition of EGFR decreased LPS-induced HSC proliferation and inflammatory cytokines. The TLR4 antagonist TAK-242, and the c-Src inhibitor, PP2 reduced EGFR activation of HSCs, indicating a possible role for the TLR4/c-Src signaling cascade in LPS-induced HSC activation. CONCLUSIONS Activation of HSCs by LPS in vitro, including the expression of inflammatory cytokines and mediators of fibrogenesis, were shown to be dependent on the expression of EGFR.

To synthesize nonmetallic magnets containing exclusively s-p orbitals with high magnetic moments and magnetic ordering is a great challenge in physics and material science. In this study, we report increased localized spin magnetic moments and observation of ferromagnetic ordering by annealing of fluorographene. It is found that the magnetic properties is sensitive to fluorine (F) distribution. The samples annealed at ca. 400–450 °C exhibits an interesting ferromagnetic state, attributing to the fragmentizing of big F clusters into many small F domains after thermo defluorination. There are high-intensity magnetic moments in the annealed samples because of the enhanced edge effect of small F clusters, which contribute to the magnetic ordering in fluorographene for a shrunken average spacing between localized moments. The increasing structure defects after annealing can be as new centers of small F domains, and greatly stabilize magnetically ordered state.

An efficient cascade reaction of propargyl amines with AgSCF3 and KBr is developed, affording allenyl thiocyanates at room temperature in high yields. This transformation proceeds via the in situ formation of isothiocyanate intermediates, followed by a [3,3]-sigmatropic rearrangement. The resulting allenyl thiocyanates bearing 3-(electro-donating phenyl) substitutions without isolation can then be reacted with di-tert-butyl peroxide and AgSCF3 under reflux to generate novel allenyl trifluoromethylthioether compounds in moderate to good yields via a “one-pot” three-step process.

To solve the problem that the curing mechanism evolution of phenolic resin catalyzed by Ba(OH)2 remained unclear, the p-p methylene index, o-p methylene index, o-o methylene index, hydroxymethyl index, and ether index were introduced to quantitatively investigate the chemical structure of resin in the curing temperature range of 90–230°C. The chemical structures were investigated by variable temperature FT-IR. The gas products released with the increase of curing temperature were characterized by Thermogravimetry-Mass Spectrometry. The curing mechanism from 90°C to 230°C was concluded finally. The results show that the main reaction is the formation of the p-p methylene group in the range of 90–120°C. It is difficult to form the o-p methylene bridge at this stage. In the range of 120–160°C, the main reaction is the formation of the p-p methylene group. From 160°C to 190°C, the main reactions are the breaking of the ether bond, the formation of the carbonyl group and the propyl bridge. Above 190°C, the main reactions are polycondensation reaction among phenolic hydroxyl groups, and the formation reaction of carbonyl groups. The ether bond breaks completely above 230°C. This work provides a new method to investigate the curing mechanism. It is a benefit for the rational design of the curing process of phenolic resin-based composites.

Heart failure characterized by cardiac remodeling is a global problem. Angiotensin II (Ang II) induces cardiac inflammation and oxidative stress, which also is implicated in the pathophysiology of adverse collagen accumulation-induced remodeling. Kaempferol (KPF), a kind of flavonoid compounds, is capable of anti-inflammatory and antioxidant activities. However, the target of KPF still remains blurred. In this study, we investigated the effect of KPF on Ang II-induced collagen accumulation and explored the underlying mechanisms. Our results suggested that KPF prevented Ang II-induced cardiac fibrosis and dysfunction, in mice challenged with subcutaneous injection of Ang II. In culture cells, KPF significantly reduced Ang II-induced collagen accumulation. Furthermore, KPF remarkably decreased inflammation and oxidative stress in Ang II-stimulated cardiac fibroblasts by modulating NF-κB/mitogen-activated protein kinase and AMPK/Nrf2 pathways.

Reactions of thiocarbonyl fluoride derived from cheap, readily available, and widely used CF

In swept source polarization depth encoding polarization sensitive optical coherence tomography (PS-OCT), the laser jitter induces additional noise to the polarization sensitive measurement. In this Letter, we developed a numerical algorithm to correct the jitter phases based on the image data using the Mueller matrix calculus. The algorithm was demonstrated on in vivo retina imaging of a guinea pig with a custom-built PS-OCT system. The performance of the proposed algorithm was almost comparable to the conventional method of using a physical calibration signal. By not requiring a hardware generated calibration signal and k -clock, the proposed algorithm is useful to reduce the complexity and the cost of a polarization depth encoding PS-OCT system.

A 26-year-old man diagnosed with nephrotic syndrome (NS) 2 years previously presented with chest pain. An electrocardiogram (ECG) performed at a local hospital showed ST-elevation in chest leads. Cardiac troponin-I was significantly positive. Echocardiography revealed mild regional wall-motion abnormalities in the heart apex. Seven days later, angiography (CAG) revealed a thrombus in the left anterior descending branch (LAD). Tirofiban was injected into the LAD for thromboclasis. ECG after CAG showed the ST-segment was much lower than before. The diagnosis after CAG was ST-segment elevation myocardial infarction (MI) and thrombogenesis in the LAD. He continued to receive antiplatelet and anticoagulation medication and atorvastatin after CAG, and was discharged 3 days later. MI is very rare in young males, but the incidence of MI is 8 times higher than normal in patients with NS. For young patients with MI, clinicians should pay more attention to the history of previous diseases with high risk of thromboembolism and they should actively promote prevention and the treatment of renal disease patients to reduce the incidence of complications of thromboembolism.

Based on Monte Carlo simulation, the magnetic properties of a mixed spin-1 and spin-3/2 Ising superlattice with alternate layers are studied. The effects of interlayer coupling and external magnetic field on the compensation behavior and hysteresis properties for the ferrimagnetic superlattice are investigated. The occurrence of a compensation point is found to be greatly affected by the interlayer coupling. In particular, various multiple hysteresis loops can be observed under certain system parameters. The calculated results agree well with available experimental and theoretical works.

Purpose To determine if myopia in albino guinea pigs is linked to altered ocular dopamine (DA) levels in both the retinal and uveal dopaminergic systems. Methods Retina and retinal pigment epithelium (RPE)/choroid were dissected from eyes of 2-week-old albino myopic (AM) and pigmented hyperopic (PH) guinea pigs. The levels of DA, dihydroxy-phenyl acetic acid (DOPAC), and homovanillic acid (HVA) were determined. Tyrosine hydroxylase (TH) and tyrosinase activities were also measured. PH animals received daily unilateral peribulbar injections of either kojic acid (tyrosinase inhibitor) or vehicle for 2 to 4 weeks. Refractive errors and ocular axial dimensions were measured by eccentric infrared photoretinoscopy and A-scan ultrasonography. Results Retinal DA levels were similar between the two strains, but AM eyes had higher levels of DOPAC. RPE/choroid DA and tyrosinase activity in AM eyes were lower than in PH eyes (P < 0.01); however, the DA turnover was higher (P < 0.05). After 2 weeks of kojic acid treatment, PH eyes developed significant myopia, accompanied by elongated vitreous chambers and axial lengths. Inhibition of tyrosinase activity was linearly correlated with a myopic refraction shift (R = 0.79, P < 0.01). PH animals that received 62.5 ng/mL kojic acid treatment daily for 2 weeks followed by 625 ng/mL for 2 more weeks became more myopic and had deeper anterior chambers compared to those that received the 62.5 ng/mL dose over this period (P = 0.04). Conclusions The uveal tyrosinase-dependent dopaminergic system is involved in the development of guinea pig refraction. Enhancing uveal tyrosinase activity might slow down the development of myopia.

Vascular endothelial dysfunction plays a crucial role in the pathogenesis of cardiovascular diseases. Oxidative stress is a key pathophysiological mechanism underpinning endothelial dysfunction. Schisandrin C (Sch C), a dibenzocyclooctadiene derivative of Schisandra chinensis, has antioxidative properties. Here, we report the use of Sch C as a novel therapeutic for the treatment of angiotensin II (Ang II)-induced endothelial deficits and explore the underlying mechanisms and the target of Sch C. Our results demonstrated that Sch C treatment prevents aorta oxidative stress and improves relaxation in mice, challenged with subcutaneous infusion of Ang II. In addition, Sch C significantly ameliorates Ang II-induced oxidative stress in rat aortic endothelial cells. We then discovered that these antioxidative effects of Sch C are mediated through the induction of nuclear factor (erythroid-derived 2)-like 2 (Nrf2). Using an expression plasmid and molecular docking, we identified that Kelch-like ECH-associated protein-1 (Keap1), a negative regulator of Nrf2, is a target of Sch C. These findings provide evidence for the potential use of Sch C as an antioxidative agent for treatment of vascular endothelial deficits.

Activated hepatic stellate cells (HSCs) are known to have a potential role in increasing the deposition of ECM and elevating proliferation in liver fibrosis, which can be driven by lipopolysaccharide (LPS). Schisandrin B (SB) is a dibenzocyclooctadiene derivative of Schisandra chinensis with anti-oxidative stress activity, but its effective target is unknown. Here, we have evaluated whether SB is protective against the LPS-induced activation of HSCs and have explored the underlying anti-oxidative stress mechanisms of SB. HSCs were treated with SB 1 h prior to LPS, and then incubated for indicated time. Nrf-2 in HSCs was inhibited genetically. The simultaneous effects on Nrf-2 activity, oxidative stress, cell proliferation, and ECM deposition were examined. SB decreased LPS-induced cell proliferation, fibrosis, and oxidative stress in HSCs. We further demonstrated that the protective effects of SB in LPS-induced HSCs activation involve the modulation of Nrf-2. SB, specifically targeting Nrf-2, attenuates the oxidative stress in HSCs. SB also reduces LPS-induced fibrosis and cell viability in HSCs. In addition, Nrf-2 may serve as a therapeutic target for infections or periods of chronic oxidative stress and may help with future drug discovery.

Atherosclerosis is recognized at present as a chronic metabolic disease of the arteries that leads to multifocal plaque development. Previous studies have reported that acid fibroblast growth factor (aFGF) is a critical therapeutic regulator in numerous chronic metabolic disorders. However, there is currently no direct evidence indicating whether aFGF serves a therapeutic role in atherosclerosis. In the present study, the role of aFGF in atherosclerotic lesion development was investigated by examining high‑fat diet (HFD)‑fed apolipoprotein E (ApoE)‑/‑ mice and parenteral administration of aFGF. Increased expression of aFGF and peroxisome proliferator‑activated receptor α (PPARα) was observed during atherosclerotic lesion development. The parenteral delivery of aFGF facilitated the progression of atherosclerosis without altering serum lipid expression levels in HFD‑fed ApoE‑/‑ mice. Furthermore, it was demonstrated that aFGF increased the expression of PPARα and inflammatory cytokines. The present results provided evidence that aFGF accelerates the progression of atherosclerosis and suggested that aFGF may be a potential therapeutic target for the prevention of atherosclerosis development.

An efficient cascade reaction of propargyl amines with AgSCF

Activated hepatic stellate cells (HSCs) serve key roles in hepatic fibrosis by producing excessive extracellular matrix (ECM) components. Lipopolysaccharide (LPS) has been found to be associated with hepatic fibrogenesis through direct interactions with HSCs. Recently, the fibroblast growth factor receptor 1 (FGFR1) signalling system was identified as a key player in the process of liver fibrosis. In the present study it was evaluated whether FGFR1 mediated LPS-induced HSCs activation. In cultured cells, FGFR1 was inhibited by either siRNA silencing or by a small-molecule inhibitor in LPS-stimulated HSCs. The blockade of FGFR1 decreased LPS-induced nuclear factor-κB (NF-κB) activation, inflammatory cytokine release, fibrosis, and cell proliferation in HSCs. It was further indicated that LPS triggered FGFR1 phosphorylation via TLR4/c-Src. These findings confirmed the detrimental effect of FGFR1 activation in the pathogenesis of LPS-related HSC activation and revealed that FGFR1 may be an ideal therapeutic target for LPS-induced liver fibrosis.

NiSnO3 nanoparticles (NPs) were loaded on reduced graphene oxide (RGO) by a facile hydrothermal technique as a anode material for lithium ion batteries (LIBs). It was found that the NiSnO3/RGO anode exhibits improved LIBs performance compared to bare NiSnO3 or RGO. The NiSnO3/RGO anode can maintain a reversible capacity of 792 mA h g−1, tested at 1200 mA g−1 after 60 cycles. When the current density was lowered in a test of rate capacity, the charge capacity was completely restored after high rate cycling at 6000 mA g−1 and maintained 889 mA h g−1 at 200 mA g−1 after 115 cycles. The enhanced LIBs performance of the NiSnO3/RGO nanocomposites can be attributed to the synergistic effects between a highly loaded NiSnO3 NPs and graphene network.

Based on Monte Carlo simulation, a model consisting of an antiferromagnetic (AFM) film coupled to a ferromagnetic (FM) film is developed to study the exchange bias and coercivity phenomenon. It is suggested that exchange bias is a consequence of exchange coupling in the AFM/FM interface, and the AFM anisotropy needs to have a threshold value for the occurrence of exchange bias. Simultaneously, exchange bias and coercivity as functions of the value of anisotropy, exchange coupling and film thickness are studied. By inducing a thickness dependence of the anisotropy in FM film, the coercivity can be reduced or enhanced by choosing suitable magnetic parameters, which can better account for the discrepancies found in previous studies. The results also provide evidence for the absence of a direct correlation between coercivity and exchange bias, which is in agreement with other studies.

Food webs are always self-organizing systems. Parasitism is ubiquitous and important in the food webs. In present study we analyzed the CSM food web with parasites and the predator-prey sub-web without parasites based on some topological indices in order to understand the effects of parasitism on robustness of food webs. The results showed that parasites dominated the food web links. The full CSM food web had more basal species and preys, and the predator-prey sub-web without parasites had more top species and predators. Existence of parasitism did not affect the similarity degree of free-living species, but would reduce the robustness of food web and increase intervality and clustering coefficient of food web.

Highly diastereoselective intramolecular trapping of ammonium ylides with enones has been developed through a Rh(II)/Brønsted acid cocatalytic strategy. This process allows rapid and efficient construction of N-unprotected polyfunctional 2,2,3-trisubstituted indolines in moderate to good yields with excellent diastereoselectivity.

Heavy metals in the soil refers to some significant heavy metals of biological toxicity, including mercury (Hg), cadmium (Cd), lead (Pb), chromium (Cr), and arsenic (As), etc. With the development of the global economy, both type and content of heavy metals in the soil caused by human activities have gradually increased in recent years, which have resulted in serious environment deterioration. In present study we compared and analyzed soil contamination of heavy metals in various cities/countries, and reviewed background, impact and remediation methods of soil heavy metal contamination worldwide.

Author(s): Jiang, Liqin; Garcia, Mariana B; Hammond, David; Dahanayake, Dinasha; Wildsoet, Christine F | Abstract: Purpose:To investigate differences in sensitivity to myopia-inducing stimuli of two strains of pigmented guinea pigs. Methods:Eleven-day-old animals (New Zealand [NZ], n = 24 and Elm Hill strains [EH], n = 26) wore either a +2 or -2 diopter (D) lens over one eye and a plano lens over the fellow eye for 5 days; other 10-day-old EH (n = 9) and 7-day-old NZ (n = 9) animals were monocularly form-deprived (FD) for 28 days. Choroidal thickness and axial length were measured using A-scan ultrasonography at baseline and after 1 and 5 days for optical defocus treatments, and at baseline and after 28 days for the FD treatment. Refractive errors were measured by retinoscopy. Choroids of untreated animals were also evaluated using spectral-domain optical coherence tomography. Results:One day of optical defocus induced bidirectional (optical sign-dependent) choroidal responses in EH animals only (P l 0.01). Similar responses were detected in NZ animals after 5 days (P l 0.01), with concordant spherical equivalent refraction changes (P l 0.01). Compared with NZ animals, EH animals developed minimal myopia with FD after 28 days (-4.58 ± 0.97 vs. -0.69 ± 0.75 D for NZ versus EH, P l 0.001). Yet, EH animals showed paradoxical choroidal thickening, 20 ± 9 vs. -8 ± 8 μm for EH versus NZ, P l 0.001. Untreated EH animals also had significantly thicker choroids than NZ animals (147 ± 19 vs. 132 ± 16 μm, P l 0.05), with well-defined layering. Conclusions:As previously reported in chicks, guinea pigs show strain-related differences in response to myopia-inducing stimuli. The finding of a thicker, multilayered choroid in the strain showing decreased sensitivity to FD is provocative, suggesting a possible protective role of the choroid.

It was recently demonstrated that chromaticity could affect eye growth and refractive development in guinea pigs but it remained unclear whether correction with spectacle lenses could balance these effects and how retinal responses change with different spectral compositions of light. Three illumination conditions were tested: blue, red and white light. Animals were raised without or with monocular spectacle lenses from three to seven weeks of age. Luminance electroretinograms (ERGs) were recorded to explore retinal responses with the different spectral compositions. In our special colony of pigmented guinea pigs, characterized by residual hyperopia, spontaneous myopia and poor emmetropization, red light induced early thinning of the choroid and relative myopia, compared to white light. Effects of red light could not be suppressed if positive spectacle lenses were worn. ERGs showed that red light failed to elicit robust retinal responses. Blue light inhibited axial eye growth, even when animals were reared with negative lenses. Intensity-matched blue and white light elicited similar a-waves but different b-waves, suggesting that the wavelength of light affects visual control of eye growth through different processing in the inner retina. We hypothesize that blue light might stimulate preferentially the ON pathway to inhibit myopia induced by negative lenses, at least in guinea pigs.

Coronary artery aneurysm (CAA) is defined as a focal or diffuse dilatation of a coronary artery, greater than 1.5 times the diameter of normal adjacent segments. Here we reported a 58-year-old woman with a background of rheumatoid arthritis and Sjogren syndrome history. Coronary angiography and Computerised tomographic (CT) coronary angiography confirmed a giant coronary aneurysm (maximum diameters of aneurysm were 12.6 mm and 8.8 mm) in the branch of left anterior descending artery, might with a fistulous communication with the pulmonary artery. To the best of our known, there were no reports about giant CCA in patient with the rheumatoid arthritis and Sjogren’s syndrome history.

Enantioselective three-component reactions of tert-butyl diazoacetate with arylamines and imines afford α,β-bis(arylamino) acid derivatives in good yields (56–90%) with high diastereoselectivities (up to >95:5 dr) and excellent enantioselectivities (up to 96% ee).

The purpose of this research was to investigate the possibility of dexamethasone (DEX)-loaded PLGA-TPGS nanoparticles (NPs) in rabbits after intravitreal administration for the treatment of posterior segment diseases. The DEX-loaded PLGA-TPGS NPs were fabricated and characterized in terms of surface morphology, particle size and size distribution, entrapment efficiency, and in vitro drug release. The animals were classified randomly into two groups: experimental group with thirty rabbits, and control group with eighteen rabbits. Rabbits in the experimental group received intravitreal injections of 0.1 mL of DEX-loaded PLGA-TPGS NPs suspension and the control rabbits received intravitreal injection of 0.1 mL DEX (20 g/L in saline). The DEX concentrations in plasma and the ocular tissues such as the cornea, aqueous humor, lens, iris, vitreous humor, and chorioretina were determined by HPLC. The DEX-loaded PLGA-TPGS nanoparticle suspension were transparent and maintained a sustained release of DEX for about 45 days in vitreous and provided relatively constant DEX levels for more than 30 days with a mean concentration of 3.93 mg/L. Based on the area-under-the-curve (AUC), the bioavailability of DEX in the experimental group was significantly higher than that in the control group administrated with regular DEX. These results suggest that intravitreal administration of DEX-loaded PL.3A-TPGS NPs leads to a sustained release of DEX with a high bioavailability, providing a basis for a novel approach to treat posterior segment diseases.

Caffeine overdose death is due to cardiac arrest, but its mechanism has not been explored in detail. In this study, our data showed that caffeine significantly prolonged the heart rate-corrected QT interval (QTc) of rabbits in vivo (P

A practical and scalable synthesis of ethyl (R)-piperidine-3-acetate was achieved from commercially available 3-pyridylacetic acid in 76% overall yield. The practical synthesis was demonstrated on 100-g scale. One-pot reductive N-ethylation of the pyridinium salt with acetonitrile gave an N-ethyl piperidine derivative.

The diastereoselectively switchable enantioselective trapping of protic carbamate ammonium ylides with imines is reported. The intriguing Rh(2)(OAc)(4) and chiral Brønsted acid cocatalyzed three-component Mannich-type reaction of a diazo compound, a carbamate, and an imine provides rapid and efficient access to both syn- and anti-α-substituted α,β-diamino acid derivatives with a high level control of chemo-, diastereo-, and enantioselectivity.

On July 26-29, 2010 the 13th International Myopia Conference was held in T�bingen, Germany and included 17 separate symposia, each with 3-5 presentations. Here, in a single paper, the chairs of those Symposia describe the scientific advances noted at the conference and include the full abstracts of the individual myopia papers presented in each symposium along with the authors and their institutions. The 17 Symposia covered 7 topics: Why Study the Mechanisms of Myopia?; Novel Approaches to Risk Factors; Signalling Eye Growth- How Could Basic Biology Be Translated into Clinical Insights?; Where Are Genetic and Proteomic Approaches Leading?; How Does Visual Function Contribute to and Interact with Ametropia?; Does Eye Shape Matter?; Why Ametropia at All?

A new approach to synthesize optically active β-amino-α-hydroxyl acid derivatives via chiral Brønsted acid-Rh(2)(OAc)(4) cocatalyzed three-component reactions of diazo acetates with alcohols and imines is reported. A matched reaction system was identified to give the products in moderate diastereoselectivity and good enantioselectivity. Application of this methodology is demonstrated in the efficient synthesis of a taxol side chain and (-)-epi-cytoxazone.

Based on Monte Carlo (MC) simulation, the magnetization behavior of mixed ferrimagnetic spin system with single-ion anisotropy under external field is investigated. It is assumed that the element of the mixed system is composed of spin-1 and spin-3/2 by turns. The simulated results indicate that there exist the magnetization curves at the ground state on the one-dimensional spin chain, two-dimensional spin system as well as three-dimensional spin system. It found that the size, anisotropy constant and spin configurations influence evidently the magnetic properties of the mixed system. Moreover, the magnetic plateaus and the phase diagrams of the systems can be well interpreted in terms of the simple calculation of energy.

Based on Monte Carlo simulation, the magnetic properties of the ferrimagnetic nanoparticles on a body-centered-cubic lattice are investigated. The particle is described by a mixed-spin Heisenberg model in which S=3/2 and σ=1 are distributed in the two interpenetrating square sublattices. It is found that no compensation point occurs at finite temperature when only the nearest-neighbor interaction between S–σ spins is included. But, when the next-nearest-neighbor interaction between σ–σ spins is taken into account and exceeds a threshold value that depends on the other parameters such as the next-nearest-neighbor interaction between S–S spins and single-ion anisotropies in the Hamiltonian, a compensation point can appear. With the appropriate order parameter which is constructed to characterize the compensation behavior clearly, a variety of phase diagrams including the finite-size effect are derived and discussed.

Ambient lighting is essential for ocular development in many species, however, disruption in diurnal lighting cycle can affect the development in refraction and axial growth of the eye. This study investigated the effects of prolonged daily lighting on refraction and various optical components of the eye by raising C57BL/6 mice under three different light/dark cycles (18/6, 12/12 and 6/18). Egr-1 mRNA expression, apoptosis and histology of the retina and size of the scleral fibrils were evaluated in these three lighting cycles. Results showed that there was a trend of myopic development, increasing vitreous chamber depth and thinning of the retina in eyes from 6/18 to 18/6 groups. Retinal Egr-1 mRNA expression and diameter of scleral fibrils were reduced with the prolongation of daily lighting from 6/18 to 18/6. However, retinal apoptosis was not detected in all the groups. These results suggest that prolonged lighting can induce axial myopia in inbred mice. This model, which uses mice with similar genetic backgrounds, provides an alternative to the currently available models and therefore is useful for evaluation of refractive errors caused by changes in environmental illumination.

This study investigated whether adolescent guinea pigs can develop myopia induced by negative lenses, and whether they can recover from the induced myopia. Forty-nine pigmented guinea pigs (age of 3 weeks) were randomly assigned to 4 groups: 2-week defocus (n=16), 4-week defocus (n=9), 2-week control (n=15) and 4-week control (n=9). A -4.00D lens was worn in the defocus groups and a plano lens worn in the control groups monocularly. The lenses were worn from 3 weeks to 5 weeks of age in the 2-week treatment groups with the biometry measured at 2, 4, 6, 10 and 14 days of lens wear. The lenses were worn from 3 weeks to 7 weeks of age in the 4-week treatment groups with the biometry measured immediately and at 2, 4, 6, 10 and 14 days after lens removal. Refractions in the defocused eyes developed towards myopia rapidly within 2 days of lens wear, followed by a slower development. The defocused eyes were at least 3.00D more myopic with a greater increase in vitreous length by 0.08 mm compared to the fellow eyes at 14 days (p

CuI/4-hydroxy-l-proline-catalyzed coupling of aryl bromides and N-Boc hydrazine takes place in DMSO at 80 degrees C to give N-aryl hydrazides. When aryl iodides are employed, this reaction completes at 50 degrees C and no ligand is required. Under the catalysis of CuI/4-hydroxy-l-proline, the coupling reaction of aqueous ammonia with aryl bromides proceeds smoothly at 50 degrees C to afford primary arylamines. In this case K(2)CO(3) is found as a better base than Cs(2)CO(3). These processes allow assembly of N-aryl hydrazides and primary arylamines that bear a wide range of functional groups including hydroxyl, amine, trifluoromethyl, ester, nitro, and ketone.

A micellar electrokinetic capillary chromatography (MEKC) method has been developed for simultaneous determination of 10 bioactive flavonoids: rutin, apigenin, luteolin, eriodictyol, kaempferol, chrysin, acacetin, flavanone, flavone, and fisetin. The effect of several parameters, such as UV detection wavelength, buffer pH, buffer concentration, sodium dodecyl sulfate (SDS) concentration, beta-cyclodextrin (beta-CD) concentration, separation voltage, and injection time on the separation of these flavonoids were systematically investigated. The 10 flavonoids were successfully separated within 18 min in 20 mM Na(2)B(4)O(7)-10 mM NaH(2)PO(4) buffer (pH 9.7) containing 100 mM SDS and 16 mM beta-CD at a separation voltage of 19 kV, with UV detection at 254 nm. Regression analysis revealed a good linear relationship between the peak area of each analyte and its concentration with detection limits (S/N = 3), ranging from 0.15 to 1.36 microg mL(-1). This method could simultaneously quantify the 10 flavonoids and be used in the quality control of functional foods containing propolis and Ginkgo biloba.

The aim of this paper is to test the feasibility of multiwalled carbon nanotubes (MWCNTs) and cigarette filters (CGFRs) as solid adsorbents for pre-concentration of DBP and DEHP in water; and to compare with C18 to investigate which has the best enrichment factor. It was found that cigarette filters exhibited the better recoveries and were therefore the best solid sorbent of the three materials tested, while multiwalled carbon nanotubes were unsuitable for enriching DBP and DEHP on account of its low recoveries. Parameters that may influence the extraction efficiency such as the eluent volume, sample flow rate, sample pH, and the sample volume were optimized. The results showed that the precisions (relative standard deviation, RSD) were 1.40% and 1.72% for DBP and DEHP under the optimal conditions. The detection limits of the developed method could reach 3.1 ng L−1 and 4.3 ng L−1 for DBP and DEHP, respectively, based on the ratio of the chromatographic signal to base line noise (S/N = 3). Satisfactory res...

A simple and sensitive kinetic-spectrophotometric method was developed for the determination of ultra trace amount of formaldehyde in food samples. The method was based on the oxidation of rhodamine B (RhB) by potassium bromate in sulfuric acid medium (formaldehyde as catalyst). The reaction was monitored by measuring the decrease in absorbance of the dye at 515 nm after 6 min. The developed method allowed the determination of formaldehyde in the range of 10-100 microg L(-1) with good precision, accuracy and the detection limit was down to 2.90 microg L(-1). The relative standard deviations for the determination of 10 and 60 microg L(-1) of formaldehyde were 3.0% and 1.9% (n = 10), respectively. The method was found to be sensitive, selective and was applied to the determination of formaldehyde in foods with satisfactory results.

Based on Monte Carlo (MC) simulation, the magnetization behavior of one-dimensional mixed ferrimagnetic spin chain with complex arrangement and single-ion anisotropy under external field are investigated. It is assumed that the element of the mixed spin chain is composed of n 1 A parallel spins with S 1 = 1 and n 2 B parallel spins with S 2 = 3 2 . The simulated results indicate that l magnetization plateaus appear at the ground state as the external field increases from zero to its saturation value. In the mean time, it is found that l is the integer part of n 1 A S 1 + n 2 B S 2 + 1 . For different anisotropy value D , there exist the degenerate states where the magnetizations are same while the corresponding spin configurations are different. Moreover, the calculated results in terms of the simple calculation of energy are associated with those simulated by MC method.