Facile identification of fluorosurfactant category in aqueous film-forming foam concentrates via optimized^(19)F NMR

Aqueous film-forming foams(AFFFs)are the primary source of toxic perfluoroalkyl and polyfluoroalkyl substances(PFAS)in wastewater.Thus,it is urgent to develop a facile and fast method for identifying fluorosurfactants in commercially available AFFFs.In this work,fluorine nuclear magnetic resonance(^(19)F NMR)spectroscopy was optimized to measure AFFFs directly with the extra addition of 5%D_(2)O as the locking reagent,and high-quality spectra could be acquired within 4 min(0.1%fluorosurfactant content).Recovery experiments demonstrated that the use of different AFFFs had no marked influence on the quantitative analysis of fluorosurfactants.Such method works with low-field NMR spectroscopy(1.4 T)as well.Two-dimensional(2D)^(19)F COSY NMR was used to make signal assignments for different fluorosurfactant derivatives.The optimized ^(19)F NMR could quantify the commercially available fluorosurfactants in different AFFFs,identify them being in either the perfluorooctane sulfonate(PFOS)or fluorotelomer sulfonic acid(FTS)categories,and distinguish the head-group of PFOS and FTS derivatives,which exhibits great potentials in the developments of relevant commercial detections.

Maximizing Function and Quality of Life of Patients with Glioblastoma after Surgical Resection: A Review of Current Literature

After surgical resection, patients with glioblastoma require many aspects of care to maximize function and quality of life. Patients face a multitude of hurdles that require the expertise of a variety of specialists. Here we will review the current literature on management of glioblastoma patients after surgical resection.

Volumetric modulation arc radiotherapy with flattening filter-free beams compared with conventional beams for nasopharyngeal carcinoma:a feasibility study

There is increasing interest in the clinical use of flattening filter-free(FFF) beams.In this study,we aimed to investigate the dosimetric characteristics of volumetric modulated arc radiotherapy(VMAT) with FFF beams for nasopharyngeal carcinoma(NPC).Ten NPC patients were randomly selected to undergo a RapidArc plan with either FFF beams(RA-FFF) or conventional beams(RA-C).The doses to the planning target volumes(PTVs),organs at risk(OARs),and normal tissues were compared.The technical delivery parameters for RapidArc plans were also assessed to compare the characteristics of FFF and conventional beams.Both techniques delivered adequate doses to PTVs.For PTVs,RA-C delivered lower maximum and mean doses and improved conformity and homogeneity compared with RA-FFF.Both techniques provided similar maximum doses to the optic nerves and lenses.For the brain stem,spinal cord,larynx,parotid glands,oral cavity,and skin,RA-FFF showed significant dose increases compared to RA-C.The dose to normal tissue was lower in RA-FFF.The monitor units(MUs) were(536 ± 46) MU for RA-FFF and(501± 25) MU for RA-C.The treatment duration did not significantly differbetween plans.Although both treatment plans could meet clinical needs,RA-C is dosimetrically superior to RA-FFF for NPC radiotherapy.

Effects of sodium ferulate on the ultrarapid delayed rectifier K^+ current in human atrial myocytes

Objective：To study the effects of sodium ferulate on the ultrarapid delayed rectifier K^＋ current（IKur） in human atrial myocytes. Methods：Human atrial myocytes were isolated by enzyme dispersion method. IKur, in human atrial myocytes were recorded by using the whole cell patch clamp. The changes of IKur were compared in the absence and the presence of sodium ferulate. Results：There was no effect of 0.4 g/L sodium ferulate on I-V relation of IKur. However, 0.4 g/L sodium ferulate inhibited IKur to some degrees at each test pulse. The current densities of IKur at ＋60 mV decreased from 4.997 ± 0.35 PA/PF to 3.331 ± 0.26 PA/PF（n = 6, P 〈 0.05）. The inhibitory effect was concentration-dependent. IC50 was（0.41 ±0.03）g/L and the Hill coefficient was 0.95 ± 0.05. Conclusion：Sodium ferulate as a potassium channel blocker can inhibit IKur in human atrial myocytes effectively.

Collection and analysis of stem exudate from soybean seedling

Vascular tissue serves as the channel for nutrient transport and signal transduc-tion between different organs in plants. To study molecular identity and behavior of mobile substances transmitted between organs via vascular tissue, it is necessary to collect exudate from stem or other organs. Modifed stem-cutting method for exudate collection in soybean was used in this study by selecting the optimum sampling time and position, using reagents preventing RNA degradation, etc. Diurnal dynamics analysis of exudate emission was found to be the highest during 10：00-10：10 am. Totally 15 μL pure exudate was collected from the stem cut between cotyledonary and unifoliolate nodes at V1 stage （unifoliolate just expanded） of young soybean seedling. Improved TRIzol method was used to extract RNA and protein from stem exudate. A phloem specifc gene of Glycine max sieve element occlusion s, SEO, in exudate samples was successfully amplifed by RT-PCR, which comfrmed the success of RNA extraction. SDS-PAGE showed the majority of proteins in exudate were of low molec-ular weight. Method proposed in this study would facilitate collection of quality exudate and enhance further investigation of mobile substances in soybean.

基于低浓度掺杂TTF-HLCT一体化分子提供的多重激子循环通道增强深蓝光OLED的稳定性

目前,商用的深蓝有机发光二极管(OLED)使用的三重态-三重态融合(TTF)型发光材料只能捕获50%的三重态(T_(1))激子,导致其器件效率较低.基于窄带蓝色发射体的热激活延迟荧光(TADF)和超荧光策略可以实现接近100%的激子利用率,然而,在发射层(EML)中停留的高能量T_(1)激子通常会导致不可避免的分子降解,从而限制了器件的使用寿命.为了解决这一问题,本文研究了一种TTF-杂化局域-电荷转移态(HLCT)一体化分子,旨在通过多个激子回收通道降低EML内T_(1)激子的密度,从而提高高效深蓝OLED的稳定性.通过TTF过程回收T_(1)激子,通过HLCT过程利用高能三重态(Tn)激子,可以提高EML中三重态激子的利用率.此外,低浓度掺杂的TTF-HLCT分子在TADF体系中可以减轻T_(1)激子猝灭造成的效率损失.最后,实现了外量子效率(EQE)为25.9%、CIE为(0.131,0.050)、蓝光指数(CE由CIEy校准)为312 cd A^(−1) CIE_(y)^(−1)的顶发射OLED,并且其寿命T90@1000 cd m^(−2)从0.5小时延长到6.1小时.本工作揭示了低浓度TTF-HLCT分子掺杂的潜力,作为一种可行的解决方案,可以最大限度地减少效率猝灭,并解决蓝光OLED的稳定性问题.

Perylene Diimide Incorporated Polyurethane Polymer as Potential Colour Filter Material with Non-fluorescent Property

A novel polyurethane polymer containing perylene diimide(PDI)unit and aniline segment,denoted as PU-PDI,was designed and synthesized.Their tensile property and photophysical characteristic were investigated using various experimental and theoretical techniques.It is found that the elongation of PU-PDIs can reach more than 1000%,indicating good tensile performance.Moreover,based on the photoinduced electron transfer mechanism,the aniline segments in polyurethane can quench the auto-fluorescence of PDI unit to a negligible value,which overcomes the intractable fluorescence drawbacks of conventional colour filters.The non-emissive characteristic,in combination with the good thermal stability and tensile property of PU-PDI,provides a feasible design strategy to fabricate optical filters with high display quality.

Design of a high-voltage electrostatic ultrasonic atomization nozzle and its droplet adhesion effects on aeroponically cultivated plant roots

In the process of aeroponics cultivation,the atomizer is one of the most important influencing factors on the cultivation process.This study presented the design of an ultrasonic atomization nozzle using contact charging and a root droplet adhesion test rig.The purpose of this study was to reveal the relationship between the main operating parameters of the high-voltage electrostatic ultrasonic atomization nozzle and the atomization effect using droplet adhesion measurements.In this study,the ultrasonic effect of nozzle was achieved by using Laval tube,and the design of the key parameters for the high-voltage electrostatic ultrasonic atomization nozzle were inlet pressure,electrostatic voltage root core electrode material and spray distance;the droplet size variation and root adhesion patterns were obtained through experiments.The best operating parameters were analyzed by using the orthogonal test method,and the droplet deposition distribution of the root system at different scales was investigated in the atomization chamber.The test results revealed that when the root core electrode material was coppe and the nozzle working parameters were at 0.4 MPa of inlet pressure,at 1.75 m the spray distance,at 12 kV of the electrostatic voltage,the root system has the highest droplet adhesion.

Quad-channel broadband compact multi-antenna GNSS down-converter for high-reliability navigation

A high-reliability broadband high-linearity down-converter for multi-antenna global navigation satellite system(GNSS)receiver is presented in this paper.Based on direction-of-arrival estimation,the multi-antenna GNSS receiver can separate the GNSS signals from the interfering signals and suppress harmful broadband radio frequency interferences.To drive the off-chip 50Ω2 resistive load and meet the stringent requirements of linearity,a quad-channel down-converter with a broadband common-gate low-noise transcon-ductance amplifier,current-driven passive mixer and novel bridge mode transimpedance driving amplifier have been proposed to contruct the multi-antenna recelver.The operating frequency of this down-converter is from 1.15 to 1.65 GHz,covering all bands for global positioning system(GPS),Beidou navigation satellite system(BDS),global navigation satellite system(GLONASS)and Galileo.The measured results show that the proposed quad-channel down-converter achieves+38 dBm output 3rd order intercept point(OIP3)and+17 dBm OP1dB(output-referred 1 dB compression point),9.5 dB to 12.9 dB noise figure(NF)across the variable gain of 10 dB to 27 dB and approximately 47 dB channel isolation.

Carbon-based perovskite solar cells with electron and hole-transporting/-blocking layers

Towards commercialization of perovskite solar cells(PSCs),further reducing the cost and increasing the stability of PSCs have been the most important tasks of researchers,as the efficiency of single-junction PSCs has reached a competitive level among all kinds of single-junction solar cells.Carbon-electrode-based PSCs(CPSCs),as one of the most promising constructions for achieving stable economical PSCs,now attract enormous attention for their cost-effectiveness and stability.Here,we briefly review the development of CPSCs and reveal the importance of n-i-p architecture for state-of-the-art CPSCs.However,despite their promising potential,challenges still exist in CPSCs in the n-i-p architecture,which mainly stem from the incompact contact of the hole-transporting layer(HTL)/carbon electrode.Thus,new carbon materials and/or novel manufacturing methods should be proposed.In addition,HTL is yet to be appropriate for state-of-the-art CPSCs because the fabrication of carbon electrode could result in the destruction of the underlayer.To further enhance the performance of CPSCs,both the HTL and electron transport layer as well as their interfaces with perovskite active layer need to be improved.We recommend that the perovskite active layer,with its long carrier lifetime,strong carrier transport capability,and long-term stability,is necessary as well for improved performance of CPSCs.We also highlight current researches on CPSCs and provide a systematic review of various types of regulation tools.

钙钛矿发光二极管外量子效率提升策略

金属卤化物钙钛矿(metal halide perovskite,MHP)因其优异的光电性能以及可溶液加工,有潜力成为下一代显示和照明设备的核心发光材料.早在20世纪90年代,就有研究人员试图将层状MHP作为发光材料,制备钙钛矿发光二极管(perovskite light-emitting diode,PeLED).但受制于不成熟的成膜方法和器件结构,器件最终只在110 K的低温下实现了正常点亮.2014年,Snaith等人首次实现了室温下正常点亮的PeLED器件.自此,越来越多的研究者关注并投入到PeLED器件的研究中.经过近5年的发展,器件外量子效率(external quantum efficiency,EQE)已得到显著提升,近红外光器件从最初的0.8%提升到20.7%,绿光器件从最初的0.1%提升到20.3%,而天蓝光器件和蓝光器件目前最高的EQE分别是12.1%和9.5%.本文从原理出发分析了限制器件外量子效率的因素.钙钛矿发光层的发光量子产率是决定器件EQE的关键因素,而电荷平衡因子和光耦合因子是进一步提升器件EQE的重要因素.由此,本文从提升钙钛矿发光层发光量子产率与调整器件结构提升电荷平衡因子和光耦合因子两方面,总结了目前文献中提升器件外量子效率的策略,指出了PeLED领域目前亟待解决的核心问题和未来发展的方向.

Recent advances in photodynamic therapy based on emerging two-dimensional layered nanomaterials

Photodynamic therapy(PDT)is a promising non-invasive therapy approach for various diseases including malignant tumor.The process of PDT involves three interrelated aspects,namely photosensitizer(PS),light source,and oxygen,among which PS is the decisive factor that determines its anticancer efficiency.There exist some defects in currently applied PDT,such as inadequate production of reactive oxygen species(ROS),poor penetration of exciting light,insufficient oxygen supply,and nonselective distribution of PS.With unique physicochemical and optical properties,two-dimensional nanomaterials(2DNMs)have aroused great interest in biomedical fields.2DNMs-based PDT is promising to significantly improve antitumor efficacy compared to conventional PDT.In this review,we will firstly introduce the underlying mechanism of PDT and how 2DNMs are absorbed and distribute inside tumor cells.After that,we will not only illustrate how 2DNMs-based PDT can enhance tumor-killing efficacy and minimize side-effects through conquering the above-mentioned defects of conventional PDT and the preparation process of 2DNMs,but also elaborate recent advances about 2DNMs-based PDT.Lastly,we will summarize the challenges and future prospects of 2DNMs-based PDT.

Inventory Policy for a Deteriorating Item with Time-Varying Demand Under Trade Credit and Inflation

It’s often the case that the supplier will provide the retailer with a permissible delay period in payments, during which the supplier charges the retailer no interest and the retailer accumulates interest earned from investment return. As a type of price reduction and an alternative to price discount,trade credit helps the supplier encourage the retailer’s ordering. This paper develops an inventory replenishment model for a deteriorating item with time-varying demand and shortages, taking account of trade credit and time value of money under inflation over a finite time horizon. This model is an extension and development of the existing studies related to the inventory system considering trade credit and time value of money and offers a more general model with more flexibility and resilience to handle the situation where demand of the end market is non-decreasing with regard to time.

Formic Acid Dehydrogenation for Hydrogen Production Promoted by Grubbs and Hoveyda-Grubbs Catalysts

In this work,we screened three Grubbs catalysts and two Hoveyda-Grubbs catalysts for the production of H_(2) by dehydrogenation of formic acid(FA).The best results were achieved with the use of a first-generation Hoveyda-Grubbs catalyst.With a catalyst loading of mere 0.5μmol, a maximum TON of 36356 was obtained within 3 h.Two key intermediates were identified by using 1H NMR and high-resolution electrospray ionization mass spectroscopy(HRESI-MS),based on which a mechanism possibly responsible for the observed catalysis was proposed.

Polymorphism and crystal transformation of penicillin sulfoxide

Penicillin sulfoxide is the intermediate for the synthesis of 7-amino-3-desacetoxycephalosporanic acid which is one of the most important nucleuses of cephalosporin antibiotic.In this contribution,two crystal structures of penicillin sulfoxide(forms I and II)were determined by X-ray diffraction,and their thermotropic properties were investigated by differential scanning calorimetry(DSC).Furthermore,the transformation of form II to form I was studied quantitatively by Raman spectroscopy,and its rates at different temperatures were determined.The results indicate that penicillin sulfoxide is more stable as form I,and the temperature plays an important role in the crystal transformation.

Introduction to the special issue of the 2009 International Symposium on Crystal Engineering&Drug Delivery Systems

On September 5-8,2009,the 2009 International Symposium on Crystal Engineering&Drug Delivery Systems was held in Tianjin,China.This conference was in succession to the 1998 and 2004 International Symposium on Industrial Crystallization that were held in Tianjin and organized by the State Research Center for Industrialization of Crystallization Technology(SRCICT)at Tianjin University.

ADVANCE NON SMALL CELL LUNG CANCER ACCEPTING CHEMOTHERAPY COMBINED WITH SHENMAI INJECTION

The aim of the study was to observe the changes of vascular endothelial growth factor(VEGF)and the efficacy of patients with advanced non-small-cell lung cancer(NSCLC)after the treatment of chemotherapy with Shenmai Injection.This study is a randomized controlled,prospective,single blind trial.63 eligible patients with NSCLC were

铂/碳纳米管催化剂的制备工艺及其应用

铂/碳纳米管催化剂适用于多相不对称氢化反应,该催化剂是在碳纳米管载体上负载铂而制成的,其制备步骤为:在硝酸中加热纯化的碳纳米管,过滤并用水洗涤碳纳米管直到滤液p H值是中性的,然后干燥碳纳米管;