Establishment and Optimization of ISSR-PCR Reaction System for Salvia przewalskii Maxim.

Based on single-factor experiment and L9( 34) orthogonal experiment,a stable ISSR-PCR reaction system of Salvia przewalskii Maxim. was established and optimized. The results indicated that the optimal concentrations of various components in a 20 μl ISSR-PCR reaction system of S. przewalskii Maxim. were: 2μl of 10 × buffer( Mg2 +),0. 4 mmol/L d NTPs,1. 0 U of Taq DNA polymerase,0. 3 μmol/L ISSR primers and 30 ng of DNA template. This study laid the foundation for the utilization of S. przewalskii Maxim. germplasm resources.

Flotation separation of wolframite from calcite using a new trisiloxane surfactant as collector

Since wolframite is usually associated with calcite,the separation and enrichment of wolframite by froth flotation remains a great challenge.Herein,a novel trisiloxane surfactant N-(2-aminoethyl)-3-ami nopropyltrisiloxane(AATS)was successful synthesized,which was used for the separation of wolframite from calcite for the first time.The flotation separation performance of AATS was studied by flotation test,and its adsorption mechanism was explored based on contact angle,infrared spectrum analysis(FTIR),zeta potential and density functional theory(DFT)calculation.The results of microflotation test and binary mixed ore flotation test pointed that AATS had excellent selectivity and more prominent collection capacity for the flotation of wolframite when compared with industrial reagent sodium oleate(NaOL).The measurement results of contact angle proved that AATS improved the hydrophobicity of the wolframite surface.The highly selective adsorption mechanism of AATS surfactant on mineral surfaces were further researched and analyzed by FTIR and zeta potential.The results revealed that AATS surfactant had significant adsorption effect on wolframite,yet almost no adsorption on calcite.DFT calculation indicated that AATS produced electrostatic adsorption with wolframite surface through—N+H3 group.

Ginsenoside Rg1 protects against ischemia-induced neuron damage by regulating the rno-miRNA-27a-3p/PPARγaxis

A preliminary miRNA screening showed that expression levels of rno-miRNA-27a-3p were significantly increased in the serum and brain tissues of rats undergoing cerebral ischemia.In recent years,there is evidence of the protective capacity of the saponins extracted from panax ginseng and its primary active ingredient ginsenosideRg1oncerebral ischemic injury.Methods:Fetal rat neurons(FRNs)were cultured in glucose-and-serumfree medium and exposed to hypoxia to establish a cerebral ischemia model in vitro(oxygen and glucose deprivation model,OGD).Antioxidant indexes(CAT,SOD),inflammatory markers(MPO,TNF-αand IL-6),and the expression of apoptosis and proliferation associated proteins(NF kB-p65,Caspase 3-cleaved,BCL-2)were examined.Results:Pre-treatment of Rg1(30–100μg/mL)could effectively inhibit the decline of antioxidant indexes(CAT,SOD)and increase in inflammatory markers(MPO,TNF-αand IL-6),and effectively inhibited the apoptosis in FRNs induced by OGD in a gradient-dependent manner.The mechanism analysis showed that the role of Rg1 in protecting against ischemia-induced neuron damage depends on its indirect up-regulation of PPAR protein via suppression of rnomiRNA-27a-3p.Moreover,these effects of Rg1 could be reversed by exogenous rno-miRNA-27a-3p and PPAR gene silencing in FRNs exposed to OGD.Conclusion:To summarize,our study demonstrates that Rg1 could effectively attenuate neuronal damage caused by cerebral ischemia via the rno-miRNA-27a-3p/PPARγpathway.Further,clarification of the novel mechanism will certainly improve our previous understanding of the role of Rg1 and enhancing its level in treatments for alleviating ischemic brain injury.

有机硅改性水性UV聚氨酯的合成与性能

以甲苯二异氰酸酯(TDI)、聚乙二醇1000(PEG1000)、双羟甲基丙酸(DMPA)、甲基丙烯酸羟乙酯(HEMA)等为原料,制备出UV固化的水性聚氨酯涂料(UV-WPU),同时用3-氨丙基三乙氧基硅烷进行改性;研究了DMPA用量、有机硅用量、中和度等对乳液黏度和涂膜吸水率的影响;采用红外光谱对聚氨酯结构进行了表征。结果表明,红外光谱分析证实产物具有预期结果;随着羧酸根(–COOH)含量增加,乳液黏度增加,涂膜吸水率提高;有机硅改性提高了水性聚氨酯(WPU)体系交联密度,使得乳液黏度增加,涂膜吸水率下降,耐水性能提高。

Acupoint injection for asthma:Systematic review of randomized controlled trials

Objective:To assess the effectiveness and safety of acupoint injection for the treatment of asthma.Methods:Six electronic databases were searched for randomized controlled trials(RCTs)of acupoint injection for asthma.Two authors extracted data and assessed methodological quality independently using the Cochrane Collaboration Risk of Bias tool.Data were evaluated using RevMan v5.2.Results:Eighteen RCTs involving 1913 participants with asthma were identified.Overall methodological quality of the RCTs was classified as unclear risk of bias.Western medicine(12 RCTs)was injected most frequently into acupoints,followed by Chinese herbal medicine(four RCTs),vitamins(one RCT),and Chinese herbal medicine combined with Western medicine(one RCT).Four RCTs used only one acupoint[ST36(two RCTs),BL13,CV22],whereas the other RCTs selected multiple acupoints(among which BL13 was used most frequently).One RCT reported mortality,no RCT reported quality of life,15 RCTs reported the symptom improvement rate,one RCT reported asthma control test(ACT)data,one RCT reported the duration of asthma,three RCTs reported the mean time that asthma was controlled(MTAC),and 13 RCTs reported lung-function tests(LFTs).Some RCTs showed acupoint injection may improve the attack time of asthma,MTAC,and LFTs.Five RCTs reported the outcome of adverse events and showed no significant differences between the acupoint injection group and control group.Conclusions:The findings suggest that acupoint injection may be effective for improving ACT data,duration of asthma,MTAC and LFTs.However,the evidence is insufficient owing to the poor methodological quality of the RCTs.

Strain Localized Deformation Variation of a Small-Scale Ductile Shear Zone

A continental-scale strike-slip shear zone frequently presents a long-lasting deformation and physical expression of strain localization in a middle to lower crustal level.However,the deformation evolution of strain localization at a small-scale remains unclear.This study investigated<10 cm wide shear zones developing in undeformed granodiorites exposed at the boundary of the continental-scale Gaoligong strike-slip shear zone.The small-scale ductile shear zones exhibit a typical transition from protomylonite,mylonite to extremely deformed ultramylonite,and decreasing mineral size from coarse-grained aggregates to extremely fine-grained mixed phases.Shearing sense indicators such as hornblende and feldspar porphyroclasts in the shear zone are the more significantly low-strain zone of mylonite.The microstructure and EBSD results revealed that the small-scale shear zone experienced ductile deformation under medium-high temperature conditions.Quartz aggregates suggested a consistent temperature with an irregular feature,exhibiting a dominated high-temperature prism <a> slip system.Additionally,coarse-grained aggregates in the mylonite of the shear zone were deformed predominantly by dislocation creep,while ultra-plastic flow by viscous grain boundary sliding was an essential deformation process in the extremely fine-grained(~50μm)mixed-phases in the ultramylonite.Microstructural-derived strain rates calculated from quartz paleopiezometry were on the order of 10^(-15) to 10^(-13) s^(-1)from low-strain mylonite to high strained ultramylonite.The localization and strain ratelimited process was fluid-assisted precipitation presenting transitions of compositions as hydrous retrogression of hornblende to mica during increasing deformation and exhumation.Furthermore,the potential occurrence of the small-scale shear zone was initiated at a middle-deep crust seated crustal condition dominated by the temperature-controlled formation and rheological weakening.

Reliability Evaluation of Wind Power Converter Under Fault-tolerant Control Scheme with Quantification of Temperature and Humidity Effects

Wind power converter(WPC)is a key part of a wind power unit which delivers electric energy to power grid.Because of a large number of semiconductors,WPC has a high failure rate.This paper proposes a method to accurately evaluate the reliability of WPC,which is crucial for the design and maintenance of wind turbines.Firstly,the index of effective temperature(ET)is presented to quantify the effects of temperature and humidity on the semiconductor operation.A novel method is proposed to evaluate the lifetime and calculate the aging failure rates of the semiconductors considering the fluctuations of ET.Secondly,the failure mode and effect analysis(FMEA)of WPC is investigated based on the topology and control scheme.The conventional two-state reliability model of the WPC is extended to the multi-state reliability model where the partial working state under the fault-tolerant control scheme is allowed.Finally,a reliability evaluation framework is established to calculate the parameters of the WPC reliability model considering the variable failure rates and repair activities of semiconductors.Case studies are designed to verfify the proposed method using a practical wind turbine.

Design of pH-responsive antimicrobial peptide melittin analog-camptothecin conjugates for tumor therapy

Melittin,a classical antimicrobial peptide,is a highly potent antitumor agent.However,its significant toxicity seriously hampers its application in tumor therapy.In this study,we developed novel melittin analogs with pH-responsive,cell-penetrating and membranelytic activities by replacing arginine and lysine with histidine.After conjugation with camptothecin(CPT),CPT-AAM-1 and CPT-AAM-2 were capable of killing tumor cells by releasing CPT at low concentrations and disrupting cell membranes at high concentrations under acidic conditions.Notably,we found that the C-terminus of the melittin analogs was more suitable for drug conjugation than the N-terminus.CPT-AAM-1 significantly suppressed melanoma growth in vivo with relatively low toxicity.Collectively,the present study demonstrates that the development of antitumor drugs based on pH-responsive antimicrobial peptide-drug conjugates is a promising strategy.

Rolling texture and its effect on tensile property of a near-α titanium alloy Ti60 plate

Rolling texture and its effect on tensile properties of Ti60 alloy plates were investigated in the present study. The plates were β-rolled at 1070℃ and(α+β)-rolled at 980℃, using uni-directionally rolling(UDR) and cross-directionally rolling(CDR) processes, respectively.β-rolled plates exhibited weak textures, which were attributed to the dispersive orientations of secondary α during the β→α phase transformation. Strong deformation textures formed in(α+β)-rolled plates as a result of slipping mechanisms: the strong T-type texture in UDR plate was related to {10 1 0}[11 2 0] slipping, while the B-type texture in CDR plate was relevant with {0001}[11 2 0] slip. Strong T-type textures led to anisotropic tensile properties. B-type textures would decrease such an anisotropy. The(α+β)-CDR process was found to be a candidate process for reducing anisotropy of Ti60 alloy plates.

Degradation of solid oxide electrolysis cells: Phenomena,mechanisms, and emerging mitigation strategies——A review

Solid oxide electrolysis cell(SOEC) is a promising electrochemical device with high efficiency for energy storage and conversion.However,the degradation of SOEC is a significant barrier to commercial viability.In this review paper,the typical degradation phenomena of SOEC are summarized,with great attention into the anodes/oxygen electrodes,including the commonly used and newly developed anode materials.Meanwhile,mechanistic investigations on the electrode/electrolyte interfaces are provided to unveil how the intrinsic factor,oxygen partial pressure pO2,and the electrochemical operation conditions,affect the interracial stability of SOEC.At last,this paper also presents some emerging mitigation strategies to circumvent long-term degradation,which include novel infiltration method,development of new anode materials and engineering of the microstructure.

粤港澳大湾区健康管理高质量发展的思考

建设粤港澳大湾区是党和国家政府重要部署的发展战略之一。发展融合创新的高质量健康管理是粤港澳大湾区大健康产业领域的重要议题。随着大湾区居民对健康医疗的诉求日益上升,健康管理的创新融合发展势在必行。但目前香港地区、澳门地区与内地在融合发展仍面临许多挑战,本文通过介绍香港地区、澳门地区两地的健康管理现状,比较和概括三地面临的融合发展的挑战,结合粤港澳大湾区的特点,从政策、经贸、教育人才、学术科研、文化观念等方面对健全大湾区健康管理的融合发展提出建议。

Framework of Probabilistic Power System Planning

This paper presents the framework of probabilistic power system planning.The basic concepts,criteria,procedure,analysis techniques and tasks of probabilistic power system planning are discussed.Probabilistic reliability evaluation and probabilistic economic assessment are two key steps.It should also be recognized that probabilistic system planning has a wider coverage than these two aspects.An actual example using a utility system is given to demonstrate an application of probabilistic transmission development planning.

Reliability evaluation of tidal and wind power generation system with battery energy storage

This paper presents a method for reliability evaluation of a hybrid generation system of wind and tidal powers with battery energy storage.Such a system may widely exist in coastal areas and islands in the future.A chronological multiple state probability model of tidal power generation system(TPGS)considering both forced outage rate(FOR)of the TPGS and random nature of tidal current speed is developed.In the evaluation of FORs of TPGS and WPGS(wind power generation system),the delivered power related failure rates of power electronic converters for TPGS and WPGS are considered.A chronological power output model of battery energy storage system(BESS)is derived.A hybrid system of tidal and wind generation powers with a BESS is used to demonstrate the effectiveness of the presented method.In case studies,the effects of various parameters on the system reliability are investigated.

Experimental verification of the potential of superhydrophobic surfaces in reducing audible noise on HVAC overhead line conductors

Overhead line conductors can generate audible noise across a wide frequency spectrum as a result of elevated electric fields at the conductor surface.Such fields are enhanced by the presence of surface defects,insects,water drops and pollution.Within this paper,the impact of a superhydrophobic coating on the audible noise produced by an overhead line conductor is examined.Noise levels from a conductor coated with a superhydrophobic coating were compared to those from a bare conductor in a semi-anechoic chamber.The conductors were energised at voltages to provide surface electric fields ranging from 6 kV/cm to 21 kV/cm(rms).With a continuous water spray system depositing droplets on the conductor surface,the frequency domain sound pressure level,overall sound pressure levels and corona discharge magnitude were measured.It is demonstrated that the use of a superhydrophobic coating reduced audible noise levels and corona discharge magnitude,especially at electric fields above 14 kV/cm.The image analysis suggests that the water drop size distribution and the position of surface droplets on the conductor circumference play an important role in the magnitude of audible noise.

Characterization of two chimeric sesterterpene synthases from a fungal symbiont isolated from a sesterterpenoid-producing Lamiaceae plant Leucosceptrum canum

Two chimeric sesterterpene synthases(Aa TPS1 and Aa TPS2)were functionally characterized from Alternaria alternata MB-30 isolated from the leaves of a sesterterpenoid-producing Lamiaceae plant Leucosceptrum canum.Aa TPS1 generated a 5/8/6/5 tetracyclic sesteraltererol(1)and its absolute stereochemistry was determined by X-ray crystallographic analysis of its derivative 10,11-epoxysesteraltererol(2),which enabled revision of the absolute configuration of C7 of sesterfisherol produced by Nf SS and PTTS014 characterized previously and its derivative 10,11-epoxysesterfisherol.Aa TPS2 produced a 5/15 bicyclic preterpestacin I(3).Site-directed mutagenesis suggested that F192 in Aa TPS1 was likely involved in controlling of the hydroxylation of C12,and eight amino acids were important for the enzyme activity of Aa TPS1 and Aa TPS2.The engineered Escherichia coli and Saccharomyces cerevisiae strains were constructed for the productions of compounds 1 and 3,and the highest titer of compound 1 reached 62.3 mg/L in shake-flask culture.Both compounds 1 and 2 showed anti-adipogenic activity.

Deformation behavior and fluid action of quartz veins in the Xuelongshan metamorphic complex,Western Yunnan

The Xuelongshan metamorphic complex underwent Cenozoic sinistral strike-slip shearing and exhumation from deep to shallow in the southeast margin of the Tibet Plateau.We studied the deformation behavior and fluid action of quartz veins in the metamorphic complex in depth based on macroscopic observation,electron backscatter diffraction fabric,and fluid inclusion analysis.The mylonitic samples are characterized by strongly elongated and orientated porphyroclasts and a finegrained matrix with a shear strain of 2.4.The ultramylonitic samples are characterized by a strongly fine-grained matrix with a shear strain of 5.8.The{m}glide controls the quartz deformation in the mylonites and ultramylonites.As the dominant recovery mechanism,subgrain rotation dynamic recrystallization reduces the grain size and promotes rheological weakening.The porphyroclasts restrict the crystal orientation of the recrystallized quartz matrix.The mylonitic quartz veins have abundant single-phase and two-phase fluid inclusions.However,the ultramylonitic quartz veins have a few fluid inclusions,most of which are small and irregular toward the grain boundaries.The temperature and pressure of fluid activity in quartz veins are 550–500℃and 391–218 MPa for ultramylonitic quartz veins,with a depth of 14.2–7.9 km and 450–400℃and 236–91 MPa for mylonitic quartz veins,with a depth of 8.6–3.3 km.The deformation process changes the shape of fluid inclusions from mylonitization to ultramylonitization and causes fluid leakage,an increase in local fluid pressure at the boundary,and hydrolysis weakening,promoting lattice dislocation glide and recrystallization,which is directly related to regional continuous shear deformation and exhumation.

Multiple Failure Modes of Compressor Station Incorporated into Risk Evaluation of Electricity-gas Integrated Energy Systems

Multiple failure modes of gas compressor stations have not been modeled into risk evaluation of electricity-gas integrated energy system(EGIES).This paper presents a method to incorporate multiple failure modes of compressor stations with bypass systems in the EGIES risk evaluation.Three outage models representing multi-states and multi-failure-modes of com-pressor stations and a bi-level Monte Carlo sampling algorithm for the models are developed.A novel network model of EGIES considering compressor stations with multiple failure modes is presented.An EGIES with a modified RBTS and an 11-node gas system is used to demonstrate the effectiveness of the proposed method and models.Results indicate that compressor stations have both positive and negative significant impacts on the risk of EGIES.Bypass systems for compressor stations can effectively offset the negative impacts.Ignoring compressor stations and their station failures in the risk evaluation of EGIES may result in an inaccurate estimation of the system risk levels and even lead to a misleading conclusion in system planning.Index Terms-Compressor station,electricity-gas integrated energy system,multiple failure modes,risk evaluation.

A review on insulation challenges towards electrification of aircraft

Compared to the traditional aircraft,electrification of power system in aircraft has potential to revolutionise the aviation industry.Typically,more-electric aircraft(MEA),even all-electric aircraft has been developed and delivered to decrease the greenhouse gas emission and increase the energy efficiency.The next generation of MEA will operate at high voltage to facilitate the transfer of significant levels of electrical power in an electrified aircraft.However,the higher voltage inevitably leads to an increased risk to the insulation of the electrical components and power system.This study aims to provide a critical overview of the insulation challenges from the perspective of electrified aircraft,typically MEA application.The development of MEA and the special working conditions are explained at the beginning.Then the insulation challenges of power modules,electric machines,aeronautical cables etc.are discussed in detail.Finally,the existing technical barriers and future prospects of insulation for electrified aircraft are summarised.It provides a reference for the future design and test in power system of next generation MEA and related electrified air transportations.

Efficient Gene Targeting in Zebrafish Mediated by a Zebrafish-Codon-Optimized Cas9 and Evaluation of Off-Targeting Effect

Targeted genome modifications with the Cas9/gRNA system derived from the clustered regularly interspaced short palindromic repeat/CRISPR-associated(CRISPR/Cas)system have been successfully used in cultured human cells as well as in most model organisms,including zebrafish(Danio rerio),mouse,and fruit fly(Chang et al.,2013;Cong et al.,2013;

Analysis and comparison of laser cutting performance of solar float glass with different scanning modes

Cutting quality and efficiency have always been important indicators of glass laser cutting.Laser scanning modes have two kinds,namely,the spiral and concentric circle scanning modes.These modes can achieve high-performance hole cutting of thick solar float glass using a 532-nm nanosecond laser.The mechanism of the glass laser cutting under these two different scanning modes has been described.Several experiments are conducted to explore the effect of machining parameters on cutting efficiency and quality under these two scanning modes.Results indicate that compared with the spiral scanning mode,the minimum area of edge chipping(218340µm)and the minimum Ra(3.01µm)in the concentric circle scanning mode are reduced by 9.4%and 16.4%respectively.Moreover,the best cutting efficiency scanning mode is 14.2%faster than that in the spiral scanning mode.The best parameter combination for the concentric circle scanning mode is as follows:Scanning speed:2200 mm/s,number of inner circles:6,and circle spacing:0.05 mm.This parameter combination reduces the chipping area and sidewall surface roughness by 8.8%and 9.6%respectively at the same cutting efficiency compared with the best spiral processing parameters.The range of glass processing that can be achieved in the concentric circle scanning mode is wider than that in the spiral counterpart.The analyses of surface topography,white spots,microstructures,and sidewall surface element composition are also performed.The study concluded that the concentric circle scanning mode shows evident advantages in the performance of solar float glass hole cutting.