Recent developments in fluorescence—based mincroscopy applied in biomedical sciences

1.IntroductionOverthelastfourdecades,fluorescencemicroscopyhasexperiencedatremendousinnovat-ingevolutionandisnowadaysawellestablishedtechniqueinmanyareasofbiomedicalre-search.Inaddition,fluorescencemicroscopicalimaginghasprovenanessentialtoolforstudy-ingbothcellstructureanddynamicprocessestakingplacewithinonecellorbetweenneigh-bouringcells.Thepresentshortreviewwillfocusonthemostrecentdevelopmentsinthisfieldofmicroscopy.2.ConventionalfluorescencemicroscopyTheterm“fluorescence”denotestheprope…     

Immunologic cell markers in acute lymphoblastic leukemia in children

Identification of surface antigens of bone marrow leukemic cells in 27 children with acute lymphoblastic leukemia in the acute period of the disease was carried out by an indirect immunofluorescence technique using monoclonal antibody panel. Series ICO (ICO-1, 02, 10, 11) of the All-Union Cancer Research Centre of the USSR Academy of Medical Sciences, and series OKT (OKT-9, 10, 6, 11, OKT-cAll, OKT-8, 4, 3) Ortho Diagnostic Systems, USA were used. Immunological subvariations of acute lymphoblastic leukemia were as follows: T-cellular population (6 cases), B-cellular population (1 case), "common cellular population" (16 cases) and O-cellular population (4 cases).     

Inter-individual differences in fMRI entropy measurements in old age

We investigated the association between individual differences in cognitive performance in old age and the approximate entropy (ApEn) measured from functional magnetic resonance imaging (fMRI) data acquired from 40 participants of the Aberdeen Birth Cohort 1936 (ABC1936), while undergoing a visual information processing task: inspection time (IT). Participants took a version of the Moray House Test (MHT) No. 12 at age 11, a valid measure of childhood intelligence. The same individuals completed a test of non-verbal reasoning (Raven's Standard Progressive Matrices [RPM]) aged about 68 years. The IT, MHT and RPM scores were used as indicators of cognitive performance. Our results show that higher regional signal entropy is associated with better cognitive performance. This finding was independent of ability in childhood but not independent of current cognitive ability. ApEn is used for the first time to identify a potential source of individual differences in cognitive ability using fMRI data.     

存在缓冲气体的Cs蒸气中的三体碰撞

研究了Cs(6P) Cs(6S) He→Cs(5D) Cs(6S) He的碰撞能量转移过程.单模半导体激光器共振激发Cs原子至6P3/2态,利用另一与泵浦激光束反向平行激光束作为吸收线探测6P3/2态原子密度及其空间分布.缓冲气体增大了6P3/2和6S1/2原子间的能量转移,这可从测量由Cs(6P)/Cs(5D)碰撞而被布居的7D态所发射的荧光得到证实.因5D→6P(3.0～3.6 μm)处于红外本实验不能探测,利用一个已经测量过的过程(即6P 5D→6S 7D)作相对测量.得到三体碰撞速率系数为(2.2±1.1)×10-28cm6s-1.     

Interference and Complexity Reduction in Multi-stage Multi-user Detection in DS-CDMA

Multi-stage parallel interference cancellation (PIC) technique gives good performance compared to successive interference cancellation (SIC) method, but biased decision statistic and complexity problems are raised due to imperfect estimation of multiple access interference (MAI) as number of stages increases. partial parallel interference cancellation (PPIC) technique is proposed to cancel the interference partially stage by stage to overcome biased problem. The complexity reduction for PIC detection is based on the convergence nature of interference cancellation which is called the difference PIC (D-PIC) detection technique. In this paper we combine (PPIC and DPIC) these two techniques and propose a multi-stage multi-user (PD-PIC) detector for performance improvement and complexity reduction compared to conventional PIC detector. The performance is degraded as the number of users increases in each technique.     

Recent advancements in surface plasmon polaritons-plasmonics in subwavelength structures in microwave and terahertz regimes

This paper presents a review of recent investigational studies on exciting Surface Plasmon Polaritons (SPPs) in MicroWave (MW) and TeraHertZ (THz) regimes by using subwavelength corrugated patterns on conductive or metal surfaces. This article also describes SPP Microstrip (MS) structures at microwave and terahertz frequencies, and compares their significance with that of conventional MS Transmission Lines (TL), in order to tackle the key challenges of high gain, bandwidth size, compactness, TL losses, and signal integrity in high-end electronic devices. Because they have subwavelength properties, surface plasmon polaritons are gaining attention for their improved performance and ability for miniaturization in high-speed dense circuits. They possess comparably minuscule wavelength compared to incident light (photons). Consequently, they can demonstrate stronger spatial confinement and higher local field intensity at optical frequencies. In addition to engineering spoof SPP waveguides, which are created by engraving grooves and slits on metal surfaces to allow operation on at low frequencies (microwave and terahertz), semiconductors with smaller permittivity values and thus lower free charge carrier concentration have been demonstrated as a potential candidate in plasmonic devices. If necessary, further tuning of semiconductor-based SPP structures is aided by controlling the charge carrier concentration through doping, or by external stimuli such as optical illumination or thermal excitation of charge carriers from valence to conduction bands. This article conclusively covers previously elucidated perspectives on manipulating SSPPs in the MW and THz ranges, and emphasizes how these could steer next-generation plasmonic devices.     

Highly Tunable Nanostructures in a Doubly pH-Responsive Pentablock Terpolymer in Solution and in Thin Films

Multiblock copolymers with charged blocks are complex systems that show great potential for enhancing the structural control of block copolymers. A pentablock terpolymer PMMA-b-PDMAEMA-b-P2VP-b-PDMAEMA-b-PMMA is investigated. It contains two types of midblocks, which are weak cationic polyelectrolytes, namely poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and poly(2-vinylpyridine) (P2VP). Furthermore, these are end-capped with short hydrophobic poly(methyl methacrylate) (PMMA) blocks in dilute aqueous solution and thin films. The self-assembly behavior depends on the degrees of ionization α of the P2VP and PDMAEMA blocks, which are altered in a wide range by varying the pH value. High degrees of ionization of both blocks prevent structure formation, whereas microphase-separated nanostructures form for a partially charged and uncharged state. While in solutions, the nanostructure formation is governed by the dependence of the P2VP block solubility of the and the flexibility of the PDMAEMA blocks on α, in thin films, the dependence of the segregation strength on α is key. Furthermore, the solution state plays a crucial role in the film formation during spin-coating. Overall, both the mixing behavior of the 3 types of blocks and the block sequence, governing the bridging behavior, result in strong variations of the nanostructures and their repeat distances.     

CMOS射频集成电路ESD保护的挑战

随着集成电路(IC)T艺进入深亚微米水平,以及射频(Radi0.Frequency,RF)IC工作频率向数千兆赫兹频段迈进,片上防静电泄放(ESD)保护设计越来越成为RF IC设计的挑战.产生这一挑战的关键原因在于ESD保护电路和被保护的RF IC核电路之间存在着不可避免的复杂交互影响效应.本文讨论了RF ESD保护的研究和设计领域的最新动态,总结了所出现的新挑战、新的设计方法和最新的RF ESD保护解决方案.     

Lightning-Induced Surges in Paired Telephone Subscriber Cable in Japan

This paper presents measured and calculated data that can be used as a basis for designing and protecting telecommunication equipment against lightning-induced surges in Japan. The paper examines the variations in geographic and environmental conditions in different parts of Japan (e.g., thunderstorm days, summer versus winter lightning, ground (soil) conductivity) and describes measured variations in lightning-induced surge characteristics in subscriber-paired cables due to differences in geographic conditions and cable conditions (e.g., cable type, buried versus aerial cable, cable length, cable height, terminal conditions, main versus branch cable). Measured lightning characteristics (e.g., front time, time-to-half-value) are compared for various measurement locations (e.g., subscriber end for subscriber cable, telephone office end for subscriber cable, telephone office end for toll cable). A general set of equations is empirically derived that predicts lightning-induced surgevoltage occurrences, front time, and time-to-half-value distributions.     

CMOS射频集成电路ESD保护的挑战

随着集成电路(IC)T艺进入深亚微米水平,以及射频(Radi0.Frequency,RF)IC工作频率向数千兆赫兹频段迈进,片上防静电泄放(ESD)保护设计越来越成为RF IC设计的挑战.产生这一挑战的关键原因在于ESD保护电路和被保护的RF IC核电路之间存在着不可避免的复杂交互影响效应.本文讨论了RF ESD保护的研究和设计领域的最新动态,总结了所出现的新挑战、新的设计方法和最新的RF ESD保护解决方案.     

Rates of convergence in the source coding theorem, in empiricalquantizer design, and in universal lossy source coding

Rate of convergence results are established for vector quantization. Convergence rates are given for an increasing vector dimension and/or an increasing training set size. In particular, the following results are shown for memoryless real-valued sources with bounded support at transmission rate R. (1) If a vector quantizer with fixed dimension k is designed to minimize the empirical mean-square error (MSE) with respect to m training vectors, then its MSE for the true source converges in expectation and almost surely to the minimum possible MSE as O(√(log m/m)). (2) The MSE of an optimal k-dimensional vector quantizer for the true source converges, as the dimension grows, to the distortion-rate function D(R) as O(√(log k/k)). (3) There exists a fixed-rate universal lossy source coding scheme whose per-letter MSE on a real-valued source samples converges in expectation and almost surely to the distortion-rate function D(R) as O((√(loglog n/log n)). (4) Consider a training set of n real-valued source samples blocked into vectors of dimension k, and a k-dimension vector quantizer designed to minimize the empirical MSE with respect to the m=[n/k] training vectors. Then the per-letter MSE of this quantizer for the true source converges in expectation and almost surely to the distortion-rate function D(R) as O(√(log log n/log n))), if one chooses k=[(1/R)(1-ϵ)log n] for any ϵ∈(0.1)     

在CdS吸收型热光双稳态现象中的空间效应

在CdS单晶片(厚度为1～3μm)上,用Ar~+激光(λ=514.5nm)作光源,实现了室温热光光学双稳态(OB),记录了热光光学双稳态下的横向空间效应和开关波。研究了在热光光学双稳态和热击穿状态下晶体的不同性状,估算出相互独立工作的热光OB元件之间的最小距离为200μm。     

Fluoride and apatite formation in vivo and in vitro

In recent years, the biomineralization process has attracted much interest from academics and industries for potential technological application. The rule in biomineralization is to have a variety of interfaces and surfaces which can act as nucleators. The ultimate step in any biomineralization process, i.e. the deposition of mineral, must conform to the driving forces operating on the system. A new paradigm in the assessment of the driving force for biomineralization is that a variety of ions existing in the mineralizing milieu are not a bystander, but are instead an active player that directly regulates the precipitation process and nature of biogenic apatites. Thus, the most putative stoichiometric model of a biomineral is (Ca)(5-x)(Mg)q(Na)u(HPO4)v(CO3)w(PO4)(3-y)(OH,F)(1-z). Fluoride participates in many aspects of calcium phosphate formation in vivo and has enormous effects on its process and on the nature and properties of the final products. In the development of biogenic apatites, fluoride ion in the mineralizing media is supposed to accelerate the hydrolysis of acidic precursor(s) and increase the growth rates by augmenting the driving force for precipitation. Inhibitory activities of ions and molecules are related to their adsorption onto the apatite surfaces. From theoretical and practical points of view, it is of paramount importance to elucidate and predict the effect and outcome of fluoride (accelerator) and inhibitors of biological relevance, because of their use in combination for healthcare in dentistry and medicine, e.g. prevention of dental caries and calculus deposition and in the formulation of antiosteoporosis treatments.     

Ballistic electron transport in semiconductor heterostructures andits analogies in electromagnetic propagation in general dielectrics

A comprehensive set of analogies between ballistic electron wave propagation in semiconductors (arbitrary kinetic energy and effective mass) and electromagnetic propagation in general dielectrics (arbitrary permittivity and permeability) is established. The expressions for electron wave propagation, reflection, and refraction are developed and shown to have the same functional form as in electromagnetics, if analogous definitions of electron wave phase and amplitude refractive indexes are used. The reflectivity characteristics such as total internal reflection (critical angle) and zero reflectivity (Brewster angle) are analyzed as a function of material parameters for both general dielectrics and semiconductor materials. The critical angle and Brewster angle results are then applied to electron wave propagation in Ga_1-xAl_xAs, where it is shown that all interfaces in this material will have both a critical angle and a Brewster angle due to differing effective masses across the interface     

Rain rate characteristics in Warsaw and in Dubna

In the years 1985-90, in frames of Intercosmos program, the measurements of 1-min average rain rate were conducted in Dubna (Russia) and in the years 1986–91 in Warsaw (Poland). In Dubna two or three tipping-bucket rain rate gauges were spaced out along the wave propagation experimental path and in Warsaw — five such sensors. Moreover in Warsaw 1-minute rain rate samples were applied for conversion of 1-minute rain rate distribution into 5-minute (10- and 20-minutes) rain rate distributions. The results of measurements and 1-minute rain rate samples conversion are presented in the paper.     

Advances in millimeter-wave subsystems in Japan

The authors describe the development trends and results of millimeter-wave systems in Japan in such fields as communication, radar, and measurement systems. The applications included are the W-40G waveguide transmission communication system, an automobile traffic control system using the 60-GHz band, a collision avoidance radar system for an automobile, a plasma electron density measuring system, and satellite communication. The authors describe the development of devices such as high-power FET amplifiers, traveling wave tube amplifiers (TWTAs), IMPATT amplifiers, low-noise amplifiers, and monolithic microwave integrated circuit (MMIC) devices used in constructing the millimeter-wave systems     

VCAT-LCAS in a clamshell

Virtual concatenation (VCAT) is a standardized layer 1 inverse multiplexing technique that can be applied to the optical transport network (OTN), synchronous optical network (SONET), synchronous digital hierarchy (SDH), and plesiochronous digital hierarchy (PDH) component signals. By inverse multiplexing, it combines multiple links at a particular layer into aggregate links to achieve a commensurate increase in available bandwidth on the aggregate link. While any inverse multiplexing scheme is about "more bandwidth", the VCAT/LCAS is a general technique that can enable a fairly broad range of network features such as (1) right sizing bandwidth for data applications, (2) bandwidth extraction from a mesh network, (3), bandwidth on demand and IP traffic engineering, and (4) provides new forms of protection-restoration and graceful degradation. In this paper, the authors have given a quick overview of VCAT/LCAS technology and just a few examples of its applications.     

Surface-wave instability in helicon wave propagation in layered structures

The mechanism of surface wave instability in helicon wave propagation in lossy, drifted layered (sandwich and multilayered) structures consisting of n-type semiconductor magnetoplasmas analyzed by Baraff and Buchsbaum is reinvestigated in the oblique geometry. The ratio of the effective masses of the charge carriers whose neglect is not justifiable in a mobile (uncompensated) semiconductor plasma is accounted for in the present treatment. Such a configuration leads to modification of the dispersion relation of the bulk helicons (helicon waves). It is concluded that the embodiment of the effective mass ratio of the charge carriers in the oblique geometry results in an increase in the actual drift velocity (above threshold velocity) giving rise to surface wave instability.     

扩频通信中的频域抗干扰技术研究

对扩频通信中的频域抗干扰滤波器进行算法的研究和仿真。频域中的滤波算法主要有TZ(Threshold Ze-roize),TC(Threshold Clipping),CMF(Condition Median Filter)等。在对已有算法仿真研究的基础上,将分段N sigma算法改进为连续的自适应门限选择算法,使得其抗干扰性能获得了一定程度的改善。以对信干比的改善性能为主要参数,对归零和钳位算法的抗干扰性能进行比较和仿真。仿真结果表明,频域误码性能有了较大改善。     

北京一次强降水过程雨滴谱特征

雨滴谱是云及降水物理学中重要的研究对象,基于北京2015年8月7日的强降水雨滴谱观测数据,计算得到该过程的雨滴谱、质量加权直径、平均直径等雨滴尺寸分布特征,由雨滴谱观测数据计算得到降水强度、液态水含量和雷达反射率,分析这些降水参数在此次降水过程中的变化特征。综合分析雨滴谱参数和S波段天气雷达反射率表明此次降水过程具有飑线特征,可划分为前端的引导对流性降水、过渡降水和尾部层状降水三个阶段。最后讨论不同降水阶段雨滴谱参数及降水参量的变化及其对雷达定量降水估测Z-R关系的影响。结果表明对流性降水阶段的雨滴数浓度（大于4600个/m3）、质量加权直径（2.69 mm）、最大直径（6.3 mm）均远高于过渡和层状降水阶段,对流降水阶段和过渡阶段雨滴直径分布范围类似（标准差均大于0.3 mm）,层状降水分布较窄（标准差0.24）。不同降水阶段拟合得到的Z-R关系明显不同,拟合得到此次降水整个过程的Z-R指数经验关系系数a=674.91,指数b=1.39。