Hollow fiber-based liquid phase microextraction followed by analytical instrumental techniques for quantitative analysis of heavy metal ions and pharmaceuticals

Hollow-fiber liquid-phase microextraction(HF-LPME)and electromembrane extraction(EME)are miniaturized extraction techniques,and have been coupled with various analytical instruments for trace analysis of heavy metals,drugs and other organic compounds,in recent years.HF-LPME and EME provide high selectivity,efficient sample cleanup and enrichment,and reduce the consumption of organic sol-vents to a few micro-liters per sample.HF-LPME and EME are compatible with different analytical in-struments for chromatography,electrophoresis,atomic spectroscopy,mass spectrometry,and electrochemical detection.HF-LPME and EME have gained significant popularity during the recent years.This review focuses on hollow fiber based techniques(especially HF-LPME and EME)of heavy metals and pharmaceuticals(published 2017 to May 2019),and their combinations with atomic spectroscopy,UV-VIS spectrophotometry,high performance liquid chromatography,gas chromatography,capillary elec-trophoresis,and voltammetry.

Intra-operative computed tomography guided navigation for pediatric pelvic instrumentation: A technique guide

Pelvic instrumentation for neuromuscular scoliosis has been part of neuromuscular scoliosis surgery since the era of the Luque Galveston construct. Unit Rod(Medtronic Sofamor-Danek, Nashville, TN) instrumentation brought with it the concept of cantilever correction by placing the implants in the pelvis and then gradually bringing the rod to the spine by sequentially tightening the sublaminar wires, with the goal of creating a level pelvis over a straight spine. More recently surgeons have utilized pedicle screw constructs in which the corrective strategies have varied. Challenges with pelvic fixation using iliac screws linked to the spinal rod have led to the development of the S2-alariliac technique(S2 AI) in which the spinal rod connects to the pelvic screw. The screw is placed in the S2 ala, crosses the sacro-iliac joint and into the ilium through a large column of supra-acetabular bone. This column is the same area used for anterior inferior iliac spine external fixation frames used in trauma surgery. S2 AI screw placement can be technically difficult and can require experienced radiology technologists to provide the appropriate views. Additionally, although the technique was originally described being placed via freehand technique with intra-operative flouroscopy, the freehand technique suffers from the anatomic anomalies present in the pelvis in neuromuscular scoliosis. As such, we prefer to place them using intra-operative navigation for all pediatric spinal deformity cases. Below in detail we report our intra-operative technique and an illustrative case example.

Microbiological assessment of indoor air of a teaching hospital in Nigeria

Objective:To investigate the quality of indoor air of different wards and units of Olabisi Onabanjo University Teaching Hospital, Sagamu, to ascertain their contribution to infection rate in the hospital.Methods:The microbial quality of indoor air of nine wards/units of Olabisi Onabanjo University Teaching Hospital, Sagamu, Nigeria was conducted. Sedimentation technique using open Petri-dishes containing different culture media was employed and samplings were done twice daily, one in the morning shortly after cleaning and before influx of people/patients into the wards/units and the other in the evening when a lot of activities would have taken place in these wards. Isolates were identified according to standard methods.Results:Results showed that there was a statistically significant difference(氈2= 6.0167) in the bacteria population of the different sampling time whereas it was not so for fungi population(氈2= 0.2857). Male medical ward(MMW) and male surgical general(MSG) recorded the highest bacterial and fungal growth while the operating theatre(OT) was almost free of microbial burden. The bacteria isolates were Staphylococcus aureus, Klebsiellasp., Bacillus cereus, Bacillus subtilis, Streptococcus pyogenes andSerratia marscenceswhile the fungi isolates includedAspergillus flavus, Penicilliumsp.,Fusariumsp.,Candida albicansandAlternariasp.Staphylococcus aureuswas the predominantly isolated bacterium whilePenicilliumsp. was the most isolated fungus.Conclusions:Though most of the microbial isolates were potential and or opportunistic pathogens, there was no correlation between the isolates in this study and the surveillance report of nosocomial infection during the period of study, hence the contribution of the indoor air cannot be established. From the reduction noticed in the morning samples, stringent measures such as proper disinfection and regular cleaning, restriction of patient relatives' movement in and out of the wards/units need to be enforced so as to improve the quality of indoor air of our hospital wards/units.

Hα measurements using DEFPOS/RTT150 Telescope: Instrumentation and observations

To investigate the physical properties of HII regions and some PNe about 4＇ in size, a DEFPOS Fabry-Perot spectrometer has been redesigned and set up at the coude exit of the 150cm RTT150 telescope （f/48） at TUBITAK National Observatory （Antalya/Baklrhtepe, Turkey）. The spectrometer has a 4＇ circular field of view and a velocity resolution of 27.27 km s^-1 （a spectral resolving power of 11000） over a 200 km s^-1 spectral window near Hα. This work presents the details of the newly redesigned instrument for coude observations, the data reduction techniques and finally presents some physical results of our new Hα observations selected from the Reynolds et al. （2005） and Fich et al. （1990） papers. The DEFPOS system has been fully tested and the first observations of HII regions and PNe in the Galaxy are used to illustrate the power of the instrument. We feel that our first Fabry-Perot observations can provide a powerful tool for the study of objects with small angular size. In the future, we are planning to prepare a catalog including some physical properties such as radial velocity, line width, and intensity of some PNe and HII regions close to the 4＇ field of view.

A low-cost and high-performance technique for adaptive optics static wavefront correction

Non-Common Path Error(NCPE) is one of the factors that limit an Adaptive Optics(AO)system from delivering ultra-high performance. To correct the NCPE associated static aberration, we propose a simple but robust and high-performance pupil-plane based wavefront measurement and correction technique, which can copy a single-mode fiber generated perfect wavefront to the AO system via an iteration optimization process, and the NCPE can be effectively corrected by directly commanding the Deformable Mirror(DM) of the AO system. Compared with the previous focal-plane based approach that uses focal plane based Point Spread Function(PSF) for correction evaluation, the pupil-plane based approach can be reliably and rapidly converged to a global optimization result and provides better performance, in particular for an AO system with a large initial static wavefront error. This technique we proposed can be implemented in astronomical AO systems where extremely high performance is required.

MEMS Test System Based on Virtual Instrument Technology

On account of the multiformity of MEMS devices, it is necessary to integrate with some optical measurement techniques for meeting static and dynamic unit test requirements. In this paper, an automated MEMS test system is built of some commercially available components and instruments based on virtual instrument technology. The system is integrated with stroboscopic imaging, computer micro-vision, microscopic Mirau phase shifting interferometry, and laser Doppler vibrometer, and is used for the measurement of full-view in-plane and out-of-plane geometric parameters and periodical motions and single spot out-of-plane transient motion. The system configuration and measurement methods are analyzed, and some applications of the measurement of in-plane and out-of-plane dimensions and motions were described. The measurement accuracy of in-plane dimensions and out-of-plane dimensional is better than 0.2 um and 5 nm respectively. The resolution of measuring in-plane and out-of-plane motions is better than 15 nm and 2 nm respectively.

A Study on the Paul-Baker System as an Instrument for Multi-object Spectrum Observation

Paul-Baker systems with 4° flat field and 5° fiat field are studied. Their light obstructions under different f/ratios of the primary mirror are analyzed. Due to the strong f/ratio of the system, a focal length extender is designed in order to match the following fiber instrumentation, and two kinds of dispersion prism correctors are designed for correcting the atmospheric dispersion. We compare the designed Paul-Baker system with LAMOST, the national major scientific project now under construction.

Genetic Algorithm Optimization Model for Determining the Probability of Failure on Demand of the Safety Instrumented System

A more accurate determination for the Probability of Failure on Demand(PFD)of the Safety Instrumented System(SIS)contributes to more SIS realiability,thereby ensuring more safety and lower cost.IEC 61508 and ISA TR.84.02 provide the PFD detemination formulas.However,these formulas suffer from an uncertaity issue due to the inclusion of uncertainty sources,which,including high redundant systems architectures,cannot be assessed,have perfect proof test assumption,and are neglegted in partial stroke testing(PST)of impact on the system PFD.On the other hand,determining the values of PFD variables to achieve the target risk reduction involves daunting efforts and consumes time.This paper proposes a new approach for system PFD determination and PFD variables optimization that contributes to reduce the uncertainty problem.A higher redundant system can be assessed by generalizing the PFD formula into KooN architecture without neglecting the diagnostic coverage factor(DC)and common cause failures(CCF).In order to simulate the proof test effectiveness,the Proof Test Coverage(PTC)factor has been incorporated into the formula.Additionally,the system PFD value has been improved by incorporating PST for the final control element into the formula.The new developed formula is modelled using the Genetic Algorithm(GA)artificial technique.The GA model saves time and effort to examine system PFD and estimate near optimal values for PFD variables.The proposed model has been applicated on SIS design for crude oil test separator using MATLAB.The comparison between the proposed model and PFD formulas provided by IEC 61508 and ISA TR.84.02 showed that the proposed GA model can assess any system structure and simulate industrial reality.Furthermore,the cost and associated implementation testing activities are reduced.

微生物快速检测技术在食品安全检测中的应用

在食品安全领域,微生物检测是确保食品质量和消费者健康的关键环节。随着食品工业的快速发展和消费者对食品安全要求的提高,传统的微生物检测方法已难以满足现代食品安全检测的要求。因此,快速检测技术成为了食品微生物检测领域的重要发展趋势。微生物快速检测技术因操作简便、检测速度快、灵敏度高和准确性好等特点在食品安全检测中表现出了巨大的应用潜力。文章对微生物快速检测技术在食品安全检测中的应用展开探讨,以期为相关人员提供参考。

氡计量标准器量值传递技术研究与应用

AlphaGUARD测氡仪被广泛用作氡标准仪器开展量值传递。本文通过标准氡室以及循环氡源验证AlphaGUARD测氡仪在低量程的准确性、高量程的一致性,并建立一定浓度范围(0.6~142.4 Bq·L^(-1))内的量值传递线性关系。为保证量值传递的可靠性,基于溯源到参考标准的氡标准仪器,将量值传递到循环氡源,分别开展以循环氡源以及标准仪器和一定浓度的水样(>5 Bq·L^(-1))作为参考标准的量值传递实验。本研究针对地下流体氡观测网内近年应用的4种新型测氡仪,制定应用氡标准仪器进行量值传递的7种技术方案,并在全国40多个氡观测站应用,其中有12个连续观测站应用2年,结果表明,校准系数相对偏差均小于5%,氡量值传递技术方案是可行的,可满足现有氡观测的校准需求。此外,还开展了传递方案的不确定度评价实验,以DDL型测氡仪为例,其最小不确定度可达5.5%(包含因子k=2)。本研究建立的新型测氡仪氡计量标准器量值传递技术方案,该方案科学可行,应用方案可有效保证新型测氡仪测值的稳定可靠。

无定位杆胫骨近端切骨引导装置在全膝关节置换术中的应用

目的探讨无定位杆胫骨近端切骨引导装置在全膝关节置换术中的应用效果。方法将无定位杆胫骨近端切骨引导装置用于40例全膝关节置换术患者的切骨定位。记录胫骨假体内外翻角误差和胫骨假体后倾角误差(均为与术前计划的差值)、术后并发症发生情况、膝关节屈曲活动度、疼痛VAS评分、膝关节HSS评分。结果患者均获得随访,时间12~56(28.2±6.1)个月。术后X线片显示胫骨假体内外翻角误差0.3°~1.7°(1.0°±0.2°),胫骨假体后倾角误差1.1°~3.0°(2.0°±0.4°)。切口均一期愈合。术后无假体松动、移位及深部感染、深静脉血栓、肺栓塞、神经血管损伤等并发症发生。末次随访时,患者均可完全负重行走,步态正常;膝关节屈曲活动度、疼痛VAS评分、膝关节HSS评分均较术前改善(P<0.05)。结论无定位杆胫骨近端切骨引导装置用于全膝关节置换术操作方便、技术可靠。

以提升研究生核心能力为导向的大型仪器平台工作优化

大型仪器是高校的重要资源,也是研究生科研能力和创新意识培养的重要支撑,平台需要不断优化和完善,从而培养研究生扎实的专业基础、完善的实验技能和持续的创新能力。因此,仪器的管理运行、技术推进、教学辅助和科研助力是大型仪器平台的重要任务。南京农业大学生命科学大型仪器平台从课程设置、教学模式、互动培训等方面强化教学,同时从技术指导、资源积累、科研融合等角度助力科研,促进了学生能力提升和科研进步。大型仪器平台的工作优化对高校的研究生培养起到了很好的辅助作用。

基于LabVIEW的考虑Sieverts装置阀门运动的PCT测试方法

针对Sieverts装置由阀门动作引起的腔体容积变化导致的储氢量计算误差,提出一种阀门容积在线标定方法。该方法结合Leachman真实气体状态方程和质量守恒定律构建数学模型;同时提出一种考虑阀门运动的PCT测试方法。基于所提出的新储氢量计算模型,借助LabVIEW软件执行阀门动作流程并进行测试程序编写,大大提高了PCT测试的精度和鲁棒性。该文详细介绍了标定装置的结构、PCT测试原理、阀门容积在线标定以及考虑阀门运动PCT测试的实现方法。通过无样品空测验证了阀门容积标定及PCT测试方法的准确性,不同储氢合金的PCT实测表明了程序的测试效果以及考虑阀门运动的必要性。

重症肺结核患者病原学阳性率及利福平耐药结果分析

目的:分析重症肺结核患者病原学阳性率及利福平耐药情况,为临床治疗重症肺结核提供参考。方法:选取2023年1—12月首都医科大学附属北京胸科医院收治的临床诊断为肺结核的369例患者为研究对象,其中145例为重症肺结核,224例为轻症肺结核。分析患者痰液抗酸杆菌染色涂片法(涂片法)、BACTEC MGIT 960液体培养法(MGIT 960法)和GeneXpert MTB/RIF(Xpert法)的阳性率及对利福平的耐药情况。结果:重症肺结核患者中,涂片法、培养法和Xpert法的阳性率及病原学总阳性率分别为47.41%(55/116)、68.75%(77/112)、85.82%(115/134)和80.69%(117/145),明显高于轻症患者[29.44%(63/214)、53.17%(109/205)、68.35%(149/218)、71.43%(160/224)],差异均有统计学意义(χ^(2)=10.580,P=0.001;χ^(2)=7.250,P=0.007;χ^(2)=12.512,P<0.001;χ^(2)=4.034,P=0.045)。Xpert法检测阳性的重症与轻症肺结核患者利福平耐药率分别为11.30%(13/115)和8.05%(12/149),差异无统计学意义(χ^(2)=0.800,P=0.371)。Xpert法阳性的重症肺结核中,复治患者利福平耐药率为24.24%(8/33),高于初治患者[6.10%(5/82)],差异有统计学意义(χ^(2)=7.727,P=0.005)。结论:相较于轻症患者,重症肺结核患者的病原学阳性率较高,且Xpert法阳性率最高。重症与轻症肺结核间利福平耐药情况无差异,而重症肺结核复治患者利福平耐药率明显高于初治患者。

激光诱导击穿光谱仪器化研制综述

作为一种新型物质探测技术,激光诱导击穿光谱(LIBS)技术因具有制样简单、非接触式测量、现场适应能力强、分析速度快以及能同时对多种元素进行识别和定量分析等突出优点,近年来在工厂运维、垃圾回收、岩矿分析、文化遗产保护、环境监测、生物医疗、食品检验、国土安全等诸多领域得到广泛应用。在从实验室逐步走向实际应用的过程中,各国研究人员开发了各式LIBS仪器,根据其大小和使用特点,大致可分为台式、远程式和便携式三类。本研究对激光诱导击穿光谱的原理、系统构成和发展脉络作了系统性的介绍,对现有的LIBS仪器进行了分类与综述,细致探讨了各类设备的优势及面临的挑战,并对未来的发展方向进行了展望。

针式组合式器械胆囊底悬吊两孔法腹腔镜胆囊切除术的技术改进及疗效分析

目的探讨腹腔镜胆囊切除术(LC)的实用减孔技术及其临床效果。方法回顾性分析2010年7月至2023年12月在宁夏回族自治区人民医院、内蒙古乌海市人民医院、宁夏吴忠市人民医院、宁夏海原县人民医院和宁夏中卫市人民医院共计1120例接受针式组合式器械胆囊底悬吊两孔法LC的患者的临床资料。经脐切口采用细头穿刺器、经剑突下微切口采用3mm穿刺器以及对胆囊动脉及胆囊管采用线扎法,分析该技术改进的临床效果。结果1120例患者中,慢性结石性胆囊炎816例,胆囊息肉82例,急性结石性胆囊炎222例。全部采用针式组合式器械悬吊胆囊底部,经脐孔上缘下方弧形切口分别插入10 mm镜鞘和5 mm操作鞘或在镜鞘旁直接插入无损伤钳;其中剑突下采用5 mm穿刺鞘890例,采用3 mm穿刺鞘230例;胆囊管和胆囊动脉的处理采用5 mm Hem-o-lok夹715例,采用丝线结扎405例。1120例中需要在右锁骨中线肋缘下增加5mm穿刺孔68例,增孔率6.07%,其中在右腋前线肋缘下再增加5mm穿刺孔21例;该68例中,因胆囊炎症重或感染胆汁外溢或胆囊大部切除需要腹腔引流而增孔者51例,因胆囊周围致密粘连或操作出血不易控制而增孔者17例。无中转开腹病例;平均手术时间(41.5±18.8)min,其中胆囊底针式器械悬吊操作时间(3.8±2.4)min;平均出血量(10.5±5.8)mL;无胆漏、胆管损伤及术后严重出血并发症。结论针式组合式器械胆囊底悬吊两孔法LC具有显露充分及操作简便的优点,可顺利完成打结技术及采用3mm器械的操作。

The Velocity Aberration Effect of the CSST Main Survey Camera

In this study,we conducted simulations to find the geometric aberrations expected for images taken by the Main Survey Camera of the Chinese Space Station Telescope(CSST)due to its motion.As anticipated by previous work,our findings indicate that the geometric distortion of light impacts the focal plane's apparent scale,with a more pronounced influence as the size of the focal plane increases.Our models suggest that the effect consistently influences the pixel scale in both the vertical and parallel directions.The apparent scale variation follows a sinusoidal distribution throughout one orbital period.Simulations reveal that the effect is particularly pronounced in the center of the Galaxy and gradually diminishes along the direction of ecliptic latitude.At low ecliptic latitudes,the total aberration leads to about a 0.94 pixel offset(a 20 minute exposure)and a 0.26 pixel offset(a 300 s exposure)at the edge of the field of view.Appropriate processings for the geometric effect during the CSST pre-and post-observation phases are presented.

Development of a Front End Array for Broadband Phased Array Receiver

The receiver is a signal receiving device placed at the focus of the telescope.In order to improve the observation efficiency,the concept of phased array receiver has been proposed in recent years,which places a small phased array at the focal plane of the reflector,and flexible pattern and beam scanning functions can be achieved through a beamforming network.If combined with the element multiplexing,all beams within the entire field of view can be observed simultaneously to achieve continuous sky coverage.This article focuses on the front-end array of phased array receiver at 0.7-1.8 GHz for QiTai Telescope,and designs a Vivaldi antenna array of PCB structure with dual line polarization.Each polarization antenna is designed to arrange in a rectangle manner by 11×10.Based on the simulation results of the focal field,32,18,and eight elements were selected to form one beam at 0.7,1.25,and1.8 GHz.An analog beamforming network was constructed,and the measured gains of axial beam under uniform weighting were 19.32,13.72,and 15.22 dBi.Combining the beam scanning method of reflector antenna,the pattern test of different position element sets required for PAF beam scanning was carried out under independent array.The pattern optimization at 1.25 GHz was carried out by weighting method of conjugate field matching.Compared with uniform weighting,the gain,sidelobe level,and main beam direction under conjugate field matching have been improved.Although the above test and simulation results are slightly different,which is related to the passive array and laboratory testing condition,the relevant work has accumulated experience in the development of the front-end array for the phased array receiver,and has good guiding significance for future performance verification after the array is installed on the telescope.

Digital Beamforming Demonstration of a Microstrip Antenna Phased Array Feeds(PAF)at 1.25 GHz

We introduce the structure of a radio astronomy phased array feeds(PAF)beamforming demonstrator.In a laboratory environment,we have demonstrated beamforming on a received 1.25 GHz sinusoidal signal and used digital weighting techniques to plot the 2D pattern of the PAF.The radio frequency part of the demonstrator includes a 4×4 linearly polarized microstrip antenna array,all of which is connected in series with a low-noise amplifier.The signals from the central 4×2 array elements are injected into a radio frequency system-on-chip digital board,which can receive eight inputs with a bandwidth of 512 MHz.Combining the principle of undersampling,the beamforming is completed at a frequency of 1.25 GHz for the offline data,and a 2D image of the beam is plotted using beam scanning technology.