Dynamically tunable vortex four-wave mixing in a six-level system.

We investigate the orbital angular momentum of vortex light in a six-level atomic system with a closed loop. We find that a vortex light field via four-wave mixing (FWM) is sensitive to the relative phase of the driving fields due to forming a closed loop configuration. Thus, it could periodically tune the phase and intensity of the vortex FWM field by adjusting the relative phase of the driving fields. Moreover, the spatial modulation of the vortex FWM phase and intensity also can be achieved by tuning the intensity of the microwave field and detuning of the driving fields.

Comparative understanding of metal hyperaccumulation in plants: a mini-review.

Hyperaccumulator plants are ideal models for investigating the regulatory mechanisms of plant metal homeostasis and environmental adaptation due to their notable traits of metal accumulation and tolerance. These traits may benefit either the biofortification of essential mineral nutrients or the phytoremediation of nonessential toxic metals. A common mechanism by which elevated expression of key genes involved in metal transport or chelation contributes to hyperaccumulation and hypertolerance was proposed mainly from studies examining two Brassicaceae hyperaccumulators, namely Arabidopsis halleri and Noccaea caerulescens (formerly Thlaspi caerulescens). Meanwhile, recent findings regarding systems outside the Brassicaceae hyperaccumulators indicated that functional enhancement of key genes might represent a strategy evolved by hyperaccumulator plants. This review provides a brief outline of metal hyperaccumulation in plants and highlights commonalities and differences among various hyperaccumulators.

Typical gene expression profile of pseudorabies virus reactivation from latency in swine trigeminal ganglion.

Pseudorabies virus (PRV) establishes a lifelong latent infection in swine trigeminal ganglion (TG) following acute infection. Increased corticosteroid levels, due to stress, increases the incidence of reactivation from latency. Muscle injection combined with intravenous deliver of the synthetic corticosteroid dexamethasone (DEX) consistently induces reactivation from latency in pigs. In this study, PRV-free piglets were infected with PRV. Viral shedding in nasal and ocular swabs demonstrated that PRV infection entered the latent period. The anti-PRV antibody was detected by enzyme-linked immunosorbent assay and the serum neutralization test, which suggested that the PRV could establish latent infection in the presence of humoral immunity. Immunohistochemistry and viral genome detection of TG neurons suggested that PRV was reactivated from latency. Viral gene expressions of IE180, EP0, VP16, and LLT-intron were readily detected at 3-h post-DEX treatment, but gB, a γ1 gene, was not detectable. The differentially expressed phosphorylated proteins of TG neurons were analyzed by ITRAQ coupled with LC-MS/MS, and p-EIF2S2 differentially expression was confirmed by western blot assay. Taken together, our study provides the evidence that typical gene expression in PRV reactivation from latency in TG is disordered compared with known lytic infection in epithelial cells.

Development of a Real-Time TaqMan PCR Method for Absolute Quantification of the Biocontrol Agent Esteya vermicola.

Esteya vermicola has been used as an effective biocontrol agent for the management of the pinewood nematode, Bursaphelenchus xylophilus. Tools for monitoring the colonization and parasitism patterns of E. vermicola are required for the development of highly effective biocontrol strategies. Because the TaqMan PCR technique is effective for quantification of species in environmental samples, a real-time PCR-based methodology was developed for absolute quantification of E. vermicola via internal standard addition and extrapolation of DNA quantity to hyphal length. Primers and a probe for the 28S ribosomal RNA gene of E. vermicola were designed, and nested TaqMan real-time PCR-based quantification was performed. In addition, internal standard-based yield measurement was correlated to the absolute quantity of target genomic DNA. Moreover, an extrapolation curve obtained by optical microscopy and image analysis of the mycelia was constructed for the measurement of fungal hyphal length. The absolute quantification method developed in the present study provides a sensitive and accurate technique to quantify fungal density in either wood or other substrate samples and can be used as an effective tool for future studies of biocontrol agents.

Storage of Airy wavepackets based on electromagnetically induced transparency.

The research of Airy beams has attained much attention due to their unique characteristics. Coherent control of Airy beams is important for further light beam manipulation and information processing. In this paper, we experimentally investigate the storage and retrieval of 2D Airy wavepackets in a solid-state medium driven by electromagnetically induced transparency (EIT). The transverse profile of the weak probe pulse is modulated by Airy wavepackets. Under EIT condition, the probe Airy wavepackets are stored into the experimental medium by manipulating the intensity of the control field, and later retrieved by the opposite process. The retrieved Airy wavepackets keep a high similarity compared with those before the storage. Furthermore, the self-healing property of the retrieved Airy wavepackets is investigated. This storage of Airy wavepackets develops the control method of Airy beams, which will be useful in further applications.

[TLR4/NF-kappaB p65 signaling pathway mediates protective effect of triptolide on endothelium in rats with endotoxemia].

The aim of this paper was to observe the effect of triptolide( TP) on cardiovascular function and its possible mechanism by intraperitoneal injection of bacterial lipopolysaccharide in rats with endotoxemia. Sixty male Sprague-Dawley rats were randomly divided intonormal group( NC group),endotoxemia model group( LPS group),TP low concentration intervention group( LPS + TP-L group,25 µg·kg~(-1)),TP middle concentration intervention group( LPS+TP-M group,50 µg·kg~(-1)),TP high concentration intervention group( LPS+TP-H group,100 µg·kg~(-1)) and polymyxin B group( LPS+PMX-B group,0. 2 mg·kg~(-1)). 10 mg·kg~(-1) LPS was injected intraperitoneally for 6 h to replicate the endotoxemia rat model. The rats in TP intervention groups were pre-treated 15 min before intraperitoneal injection of LPS. Rats in each group underwent total arterial intubation to measure hemodynamic parameters: heart rate( HR),left ventricular diastolic pressure( LVDP),the maximum rate of the increase/decrease of left ventricular pressure( ±dp/dtmax). The levels of BNP,CK-MB and c Tn-Ⅰ in serum and levels of TNF-α and IL-6 in plasma were detected by ELISA. The contents of p65 protein in myocardium and contents of p65,TLR4,i NOS and e NOS protein in thoracic aorta were detected by Western blot. As compared with NC group,the hemodynamic indexes in LPS group were significantly decreased; the contents of BNP,CK-MB and c Tn-Ⅰ in serum,TNF-α and IL-6 in plasma,p65 in myocardium,i NOS,e NOS,TLR4 and p65 in vascular tissues were significantly increased. As compared with LPS group,the hemodynamic indexes were significantly improved in LPS+TP-M group,LPS+TP-H group and LPS+PMX-B group; the contents of BNP,CK-MB and c Tn-Ⅰ in serum,TNF-α and IL-6 in plasma,p65 in myocardium,i NOS,e NOS,TLR4 and p65 in vascular tissues were significantly decreased in each treatment group. Triptolide has a protective effect on cardiovascular damage in a dose-dependent manner in endotoxemia rats,probably through TLR4/NF-κB p65 signaling pathway to improve endothelial function.

An Uncommon Carboxyl-Decorated Metal-Organic Framework with Selective Gas Adsorption and Catalytic Conversion of CO2.

A new three-dimensional (3D) framework, [Ni(btzip)(H2 btzip)]⋅2 DMF⋅2 H2 O (1) (H2 btzip=4,6-bis(triazol-1-yl)isophthalic acid) as an acidic heterogeneous catalyst was constructed by the reaction of nickel wire and a triazolyl-carboxyl linker. Framework 1 possesses intersected 2D channels decorated by free COOH groups and uncoordinated triazolyl N atoms, leading to not only high CO2 and C2 H6 adsorption capacity but also significant selective capture for CO2 and C2 H6 over CH4 and CO in 273-333 K. Moreover, 1 reveals chemical stability toward water. Grand Canonical Monte Carlo simulations confirmed the multiple CO2 - and C2 H6 -philic sites. As a result of the presence of accessible Brønsted acidic COOH groups in the channels, the activated framework demonstrates highly efficient catalytic activity in the cycloaddition reaction of CO2 with propylene oxide/4-chloromethyl-1,3-dioxolan-2-one/3-butoxy-1,2-epoxypropane into cyclic carbonates.

Controlling transverse shift of the reflected light via high refractive index with zero absorption.

We present a theoretical investigation on controlling the transverse shift while most of the researches are on longitudinal Goos-Hänchen shift. A two-layer system is considered. The refractive index of the first layer is fixed. The second layer is an atomic system coupled by a strong laser field to realize the Λ-style electromagnetically induced transparency, and an additional microwave field drives the transition between the lower two levels to construct high refractive index with zero absorption. We use such phenomenon to modify the refractive index, and consequently the transverse shift in reflection. The properties of the atomic system and the transverse shift of reflected field are briefly studied. Our investigation shows that the shift can be tuned by the strength of the microwave field. And since the atomic system is quite sensitive to the phase of the light fields, through which the transverse shift can be manipulated effectively. More importantly, the absorption is limited due to the presence of the microwave field.

Construction of Highly Porous Pillared Metal-Organic Frameworks: Rational Synthesis, Structure, and Gas Sorption Properties.

Different from the conventional method to construct pillared-layer metal-organic frameworks (MOFs) by using mixed bipyridyl and dicarboxylate ligands, herein, we present a new approach to build pillared-layer frameworks based on the pyridyldicarboxylate ligands which were predesigned with a certain shape. As exemplified, the ligands of 3-(2',5'-dicarboxyphenyl)benzoic acid (H3dbba) and 3-(2',5'-dicarboxylphenyl)pyridine acid (H2dcpy) were selected and employed to construct three pillared-layer MOFs, [Zn3(dbba)2(bipy)(DMF)]·3DMF·4H2O (1) (bipy = 4,4'-bipyridine), and a pair of crystal polymorphs of [Zn(dcpy)]·1.5DMF·1.5H2O (2 and 3), under solvothermal reactions, respectively. In the structures of 1-3, the [Zn2(COO)4] clusters are bridged by the terephthalate units of dbba3-/dcpy2- to form 2D layers; these layers are further pillared by bipy and the benzoate units of dbba3- or the pyridine units of dcpy2- to furnish the 3D frameworks. All of them possess high porosity characterized by N2 adsorption and exhibit high selective adsorption of C2H4 and CO2 over CH4.

Lysobacter zhanggongensis sp. nov. Isolated from a Pit Mud.

The Gram-stain-negative, rod-shaped and non-motile bacterial strain, designated ZGLJ7-1T, was isolated from a pit mud. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain ZGLJ7-1T was related to the genus Lysobacter and had the highest 16S rRNA gene sequence similarity with the type strain of Lysobacter arseniciresistens ZS79T (97.4%). The predominant cellular fatty acids were iso-C15:0, iso-C17:1ω9c, iso-C11:0 and iso-C11:03-OH. Strain ZGLJ7-1T had Q-8 as the predominant ubiquinone. The polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unidentified phospholipid, two unidentified aminolipids and two unidentified lipids. The genomic DNA G+C content of strain ZGLJ7-1T was 69.5 mol%. Strain ZGLJ7-1T shared DNA relatedness with 35% Lysobacter arseniciresistens CGMCC 1.10752T. Combined data from phenotypic, phylogenetic and DNA-DNA relatedness studies demonstrated that the strain ZGLJ7-1T is a representative of a novel species of the genus Lysobacter, for which we propose the name Lysobacter zhanggongensis sp. nov. (type strain ZGLJ7-1T = KACC 18547T = CGMCC 1.15404T).

A Cationic MOF with High Uptake and Selectivity for CO2 due to Multiple CO2 -Philic Sites.

The reaction of N-rich pyrazinyl triazolyl carboxyl ligand 3-(4-carboxylbenzene)-5-(2-pyrazinyl)-1H-1,2,4-triazole (H2 cbptz) with MnCl2 afforded 3D cationic metal-organic framework (MOF) [Mn2 (Hcbptz)2 (Cl)(H2 O)]Cl⋅DMF⋅0.5 CH3 CN (1), which has an unusual (3,4)-connected 3,4T1 topology and 1D channels composed of cavities. MOF 1 has a very polar framework that contains exposed metal sites, uncoordinated N atoms, narrow channels, and Cl(-) basic sites, which lead to not only high CO2 uptake, but also remarkably selective adsorption of CO2 over N2 and CH4 at 298-333 K. The multiple CO2 -philic sites were identified by grand canonical Monte Carlo simulations. Moreover, 1 shows excellent stability in natural air environment. These advantages make 1 a very promising candidate in post-combustion CO2 capture, natural-gas upgrading, and landfill gas-purification processes.

A new porous MOF with two uncommon metal-carboxylate-pyrazolate clusters and high CO2/N2 selectivity.

By a less-exploited strategy, a stable framework was constructed by using 4,4'-biphenyldicarboxylic acid (H2bpdc) and methyl-functionalized 3,3',5,5'-tetramethyl-4,4'-bipyrazole (H2bpz) coligands, revealing a new (6,8)-connected net based on two extremely rare trinuclear and tetranuclear metal-carboxylate-pyrazolate clusters. The framework is very porous and possesses not only high CO2 loadings but also very high CO2/N2 selectivities at 308 and 313 K because of the polar pore surface decorated by clusters, pyrazolyl units, and confined cages with methyl groups dangling. Importantly, GCMC simulation identified two favorable CO2 sorption sites located sequentially near Co3(pz)3 and Co3(CO2)2(pz) motifs of the tetranuclear cluster, and the multipoint framework-CO2 interactions were distinguished. The framework also displays remarkable stability toward water and organic solvents.

[Regulation Mechanism of Ginkgo-Dipyridamolum for Calcium Homeostasis on Cardioprotective Effect During Ischemia Reperfusion Injury].

OBJECTIVE: To explore regulatory mechanism of Ginkgo-dipyridamolum (GD) for calcium homeostasis on cardioprotective effect during ischemia reperfusion injury in the isolated rat heart. METHODS: 40 male SD-rats were randomly divided into five groups (n = 8): normal control group (NC), ischemia reperfusion group (IR), GD precondition group (GD + IR), Nicardipine and GD precondition group( Nic + GD + IR), and LaCl3 and GD precondition group (LaCl, + GD +IR). The hearts of rats were isolated after anesthesia and performed to profuse with Langendorff equipment. The heart functional indexes (HR, LVSP and ± dp/dt(max)) were detected at the five time points (stabilize point, ischemia 30 min, reperfusion 5 min, reperfusion 30 min, and reperfusion 60 min). The coronary effluents were also collected at the five time points. The activities of LDH and CK were measured, respectively, as well as the Ca2+ contents. After the experiments were finished,the myocardial mitochondria were isolated, homogenated and then the Ca2+ concentrations, the activities of IDH and α-OGDH were detected. The pathologic changes in myocardial tissues were also observed by histologic section. RESULTS: Compared with IR group, the heart functional indexes ( LVSP x HR and ± dp/dt(max)) of GD + IR group were improved at the five time points; the enzymes (LDH and CK) release, the Ca2+ concentrations, the activities of IDH and α-OGDH were reduced in mitochondrion. However, the protective effects above could be inhibited by Nic and LaCl3. Histologic sections showed that the myocardial tissue in IR group was damaged obviously, the damaged myocardial tissues were repaired in GD + IR, Nic + GD + IR and LaCl, + GD + IR) groups, especially in GD + IR group. CONCLUSION: Ginkgo-dipyridamolum can alleviate the myocardial ischemia reperfusion injury, the mechanism is probobaly related to maintaining calcium homeostasis and mitochondrial energy metabolism function.

Pseudomonas hunanensis sp. nov., isolated from soil subjected to long-term manganese pollution.

A Gram-negative, polar flagella, rod-shaped bacterium LV (T) was isolated from a soil sample subjected to long-term manganese pollution in Hunan Province, China. Cells grow optimally on Luria-Bertani agar medium at 30 °C in the presence of 0-5.0 % (w/v) NaCl and pH 7-8. 16S rRNA gene sequence analysis revealed that strain LV (T) belonged to the genus Pseudomonas, with sequence similarity values of 98.6, 98.2, 98.7, and 97.3 % to Pseudomonas monteilii BCRC 17520 (T) , Pseudomonas putida BCRC 10459 (T) , Pseudomonas plecoglossicida BCRC 17517 (T) , and Pseudomonas asplenii BCRC 17131 (T) , respectively. The level of DNA-DNA relatedness between the five strains was <30 %. The DNA G+C content of strain LV (T) is 68.8 mol%. Chemotaxonomic data revealed that the strain LV(T) possesses ubiquinone Q-9. The polar lipid profile of strain LV (T) contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, and phosphatidylethanolamine. The major cellular fatty acids present are C10:03-OH (12.33 %), C16:0 (23.99 %), summed feature 3(C16:1ω7c and/or C16:1ω6c), and summed feature 8(C18:1 ω7c and C18:1 ω6c). Based on the genotypic, chemotaxonomic and phenotypic data, strain LV (T) is distinguishable from related members of the genus Pseudomonas. Thus, strain LV (T) represents a novel species of the genus Pseudomonas, for which the name Pseudomonas hunanensis sp. nov. is proposed. The type strain is LV (T) (=CICC 10558(T) = NCCB 100446(T)).

Suppression of the SLC7A11/glutathione axis causes ferroptosis and apoptosis and alters the mitogen-activated protein kinase pathway in nasopharyngeal carcinoma.

SLC7A11 is a unit of the glutamate cystine antiporter Xc- system. It functions to import cystine for glutathione biosynthesis and maintains the redox balance in cells. Sorafenib inhibits the transporter activity of SLC7A11. The use of sorafenib has been approved in the treatment of multiple cancers. However, at present, our understanding of the mechanism of SLC7A11 and sorafenib in nasopharyngeal carcinoma (NPC) remains limited. We found that the expression of SLC7A11 was upregulated in NPC. A high SLC7A11 expression was associated with poor prognosis, metastasis, and an advanced T stage, which can be used as an independent prognostic indicator of NPC. In vitro, we observed that NPC cells relied on cystine for survival. Targeting SLC7A11 resulted in glutathione biosynthesis limitation, intracellular reactive oxygen species accumulation, lipid peroxides, ferroptosis, and apoptosis. Meanwhile, it altered mitogen activated protein kinase pathway, including p38 activation but ERK inhibition in NPC. This limited the proliferation of NPC cells. Sorafenib inhibited the proliferation and induced the death of NPC cells in vivo. In conclusion, SLC7A11 plays an important role in the occurrence and progression of NPC and may be a novel target for NPC treatment.

Electromagnetically induced grating based on the giant Kerr nonlinearity controlled by spontaneously generated coherence.

We propose a scheme for realizing electromagnetically induced grating via the giant Kerr nonlinearity in a coherently driven four-level system with spontaneously generated coherence. In the presence of spontaneously generated coherence, Kerr nonlinearity can be enhanced with vanishing linear absorption. Thus, with a standing-wave coupling field, one can achieve a pure absorption grating, which leads the probe field to gather the zero-order direction when the detuning of the coupling field is on resonance. Moreover, we can obtain a pure phase grating, which diffracts a weak probe light into the first-order direction and the second-order direction when the detuning of the coupling field is off resonance.

[Detection of onion soluble solids content based on the near-infrared reflectance spectra].

Onion soluble solids content (SSC) was detected using near-infrared (924-1720 nm) reflectance spectra. Three cultivars of onions, harvested at different period, were selected for experiment and the total number of samples is 268. SSC reference value of onion juice was determined using the temperature compensated refractometer. Some pre-processing methods, such as S-G smoothing, scatter correction, and derivation, were compared to establish a statistical model based on partial least squares regression (PLSR) method. The results show that the avitzky-Golay smoothing with window 32 and span 10 is more efficient. The determination correlation coefficient of prediction R2 is 0.87 and root mean square error (RMSEP) is 2.42 degrees Brix. Compared to the 2nd derivation, the 1st derivation got better prediction result, but the spectra scatter correction is the best (R2 = 0.88, RMSEP of = 2.31 degrees Brix). The optimal prediction (R2 = 0.90, RMSEP = 1.84 degrees Brix and RPD = 3) was built based on crossing validation modeling, which shows that infrared reflectance spectroscopy with scatter correction pre-processing is feasible for onions soluble solids detection.

[Multiple scattering of visible and infrared light by sea fog over wind driving rough sea surface].

The present paper is concerned with computing the multiple scattering characteristics of a sea fog-sea surface couple system within this context. The single scattering characteristics of sea fog were studied by Mie theory, and the multiple scattering of sunlight by single sea fog layer was studied by radiative transfer theory. The reflection function of a statistically rough ocean surface was obtained using the standard Kirchhoff formulation, with shadowing effects taken into account. The reflection properties of the combined sea fog and ocean surface were obtained employing the adding method, and the results indicated that the reflected light intensity of sea fog increased with the sea background.

Dye-sensitized solar cells based on highly catalytic CNTs/Ti3C2Tx MXenes composite counter electrode.

Establishing stable and efficient Pt-free counter electrodes (CEs) is an important challenge for dye-sensitized solar cells (DSSCs). Ti3C2Tx MXene, with its high catalytic activity and conductivity, has gained attention as a CE in DSSCs. The focus of this paper is on the preparation of Ti3C2Tx decorated carbon nanotubes (CNTs) composite electrode materials (CNTs/Ti3C2Tx), and testing their performance as CEs in DSSCs. Through a series of electrochemical tests, a CNTs/Ti3C2Tx CE exhibits good electrocatalytic activity toward iodine-based electrolytes with low charge transfer resistance, which is close to the performance of a Pt CE. The photoelectric conversion efficiency (PCE) of the CNTs/Ti3C2Tx (1.0 wt%) CE-based DSSCs reaches 5.83%, which is much higher than that of the CNTs CE (3.70%), and approximates that of the Pt CE (6.61%). We attribute the improved performance to the synergistic effect of the excellent conductivity and unique two-dimensional chemical structure of Ti3C2Tx MXene. Moreover, the photostability test of continuous light exposure shows that the CNTs/Ti3C2Tx-1.0 wt% (C/T-1.0 wt%) CE exhibits good stability to the electrolyte. Therefore, CNTs/Ti3C2Tx composites can be used as an efficient Pt-free CE for DSSCs in the future.

Observation of the fluorescence spectrum for a driven cascade model system in atomic beam.

We experimentally study the resonance fluorescence from an excited two-level atom when the atomic upper level is coupled by a nonresonant field to a higher-lying state in a rubidium atomic beam. The heights, widths and positions of the fluorescence peaks can be controlled by modifying the detuning of the auxiliary field. We explain the observed spectrum with the transition properties of the dressed states generated by the coupling of the two laser fields. We also attribute the line narrowing to the effects of Spontaneously Generated Coherence between the close-lying levels in the dressed state picture generated by the auxiliary field. And the corresponding spectrum can be viewed as the evidence of Spontaneously Generated Coherence. The experimental results agree well with calculations based on the density-matrix equations.