抗体制剂乳光现象与分子粒径及聚集倾向性研究

目的:对抗体制剂乳光现象与分子粒径、纯度及聚集倾向性的相关性进行系统研究。方法:通过研究多种抗体的乳光现象,其中包含不同浓度、pH/缓冲盐及辅料对乳光现象的影响,以及温度、光照、反复冻融及振荡等环境因素的影响,分析乳光现象与分子粒径、纯度(聚集体)、扩散相互作用指数(K_(D))及聚集温度(T_(agg))之间的关联。结果:抗体制剂乳光与分子粒径大小呈正相关,乳光程度的加深表明分子粒径有所增加且分子聚集倾向性增加,如C分子在高温条件下,乳光现象明显加深,浊度由3.3 NTU变为13.6 NTU,粒径由13.1 nm变为40.6 nm,K_(D)由正变负,T_(agg)由59.6℃变为50℃以下。结论:缓冲体系、pH及辅料等处方因素,以及温度等条件均会影响抗体制剂的乳光特性,乳光程度增加,预示制剂稳定性降低,更容易发生聚集。本研究为抗体药物制剂生产中乳光的检测评价提供重要参考。

高密度CO2对虾肌球蛋白微观形貌的影响

以凡纳滨对虾肌球蛋白为研究对象,用原子力显微镜观察高密度CO_2(dense phase carbon dioxide,DPCD)处理压强、温度和时间对肌球蛋白微观形貌的影响,探讨DPCD处理过程中肌球蛋白的聚集行为特征。结果表明:在不同的DPCD处理压强、温度和时间条件下,肌球蛋白变性和聚集的程度有显著差异;DPCD诱导肌球蛋白变性聚集过程中,不仅有热效应引起的蛋白质分子间的相互作用,还有高压下CO_2与蛋白质分子间的相互作用。

MEASUREMENTS OF PARTICLE NUMBER SIZE DISTRIBUTIONS AND NEW PARTICLE FORMATION EVENTS DURING WINTER IN THE PEARL RIVER DELTA REGION,CHINA

Particle number size distribution(PNSD) between 10 nm and 20 μm were measured in the Pearl River Delta(PRD) region in winter 2011.The average particle number concentration of the nucleation mode(10-20 nm),Aitken mode(20-100 nm),accumulation mode(100 nm-1μm) and coarse mode(1-20 μm) particles were 1 552,7 470,4 012,and 19 cm-3,respectively.The volume concentration of accumulation mode particles with peak at 300 nm accounted for over 70% of the total volume concentration.Diurnal variations and dependencies on meteorological parameters of PNSD were investigated.The diurnal variation of nucleation mode particles was mainly influenced by new particle formation events,while the diurnal variation of Aitken mode particles correlated to the traffic emission and the growth process of nucleation mode particles.When the PRD region was controlled by a cold high pressure,conditions of low relative humidity,high wind speed and strong radiation are favorable for the occurrence of new particle formation(NPF) events.The frequency of occurrence of NPF events was 21.3% during the whole measurement period.Parameters describing NPF events,including growth rate(GR) and source rate of condensable vapor(Q),were slightly larger than those in previous literature.This suggests that intense photochemical and biological activities may be the source of condensable vapor for particle growth,even during winter in the PRD.

Size Distributions and Source Function of Sea Spray Aerosol over the South China Sea

The number concentrations in the radius range of 0.06 – 5 μm of aerosol particles and meteorological parameters were measured on board during a cruise in the South China Sea from August 25 to October 12, 2012. Effective fluxes in the reference height of 10 m were estimated by steady state dry deposition method based on the observed data, and the influences of different air masses on flux were discussed in this paper. The number size distribution was characterized by a bimodal mode, with the average total number concentration of（1.50 ± 0.76）×10~3 cm^（-3）. The two mode radii were 0.099 μm and 0.886 μm, both of which were within the scope of accumulation mode. A typical daily average size distribution was compared with that measured in the Bay of Bengal. In the whole radius range, the number concentrations were in agreement with each other; the modes were more distinct in this study than that abtained in the Bay of Bengal. The size distribution of the fluxes was fitted with the sum of log-normal and power-law distribution. The impact of different air masses was mainly on flux magnitude, rather than the shape of spectral distribution. A semiempirical source function that is applicable in the radius range of 0.06 μm

Method for grinding and delaminating muscovite

A method of dry grinding muscovite based on the use of knife-mills is reported.It was possible to produce mica with a particle size below 100 and 45μm.After grinding,the samples were submitted to sonication treatment,which promoted delamination of the material.The particle size distribution shows that sonicated mica has more particles in the size range 10-50μm than does non-sonicated mica have. This also indicates a decrease in the average particle size.Characterization of the treated muscovite by scanning electron microscopy revealed a highly delaminated material with a plate-like structure.The products were characterized by chemical analysis and X-ray diffraction,too.This mica has already been used for the synthesis of pearlescent pigments.

Multi-path routing algorithm in WSN using an improvedparticle swarm optimization

To slove the problems of constrained energy and unbalanced load of wireless sensor network(WSN)nodes,a multipath load balancing routing algorithm based on neighborhood subspace cooperation is proposed.The algorithm adopts the improved particle swarm optimization(PSO)algorithm,takes the shortest distance and minimum energy consumption as optimization target and divides the nodes in one-hop neighborhood near the base station area into different regions.Furthermore,the algorithm designs a fitness function to find the best node in each region as a relay node and forward the data in parallel through the different paths of the relay nodes.The simulation results show that the proposed algorithm can reduce energy consumption and average end-to-end delay,balance network load and prolong network lifetime effectively.

Nanoparticle Migration in a Fully Developed Turbulent Pipe Flow Considering the Particle Coagulation

Numerical simulations of nanoparticle migration in a fully developed turbulent pipe flow are performed.The evolution of particle number concentration,total particle mass,polydispersity,particle diameter and geometric standard deviation is obtained by using a moment method to approximate the particle general dynamic equation.The effects of Schmidt number and Damkhler number on the evolution of the particle parameters are analyzed.The results show that nanoparticles move to the pipe center.The particle number concentration and total particle mass are distributed non-uniformly along the radial direction.In an initially monodisperse particle field,the particle clusters with various sizes will be produced because of coagulation.As time progresses,the particle cluster diameter grows from an initial value at different rates depending on the radial position.The largest particle clusters are found in the pipe center.The particle cluster number concentration and total particle mass decrease with the increase of Schmidt number in the region near the pipe center,and the particles with lower Schmidt number are of many dif-ferent sizes,i.e.more polydispersity.The particle cluster diameter and geometric standard deviation increase with the increase of Damkhler number at the same radial position.The migration properties for nano-sized particles are different from that for micro-sized particles.

Particle Paths of Lagrangian Velocity Distribution Simulating Yin-Yang Balance in Ancient Tai-Chi Diagram

The particle paths of the Lagrangian flow field simulate very well the interface curve of the Yin-Yang balance in the ancient Tal-Chi diagram. There are four forms called the ＂four states＂ in the Tai-Chi diagram. Of the four states, under Yang are the Major Yang and the Minor Yin, and under Yin are the Major Yin and the Minor Yang. The present study provides the proper positions of the four states in the ancient Tal-Chi diagram. The Fu Xi＇s Eight Trigrams Chart located along the ancient Tai-Chi diagram is also developed in the present study. The interface curve of Yin-Yang in the ancient Tai-Chi diagram has never been described mathematically. It can now be formulated by the equations describing the particle paths in the Lagrangian flow field.

Solutions without a maximum mass limit of the general relativistic field equations for neutron stars

We have investigated the general relativistic field equations for neutron stars.We find that there are solutions for the equilibriummass distribution without a maximum mass limit.The solutions correspond to stars with a void inside their centers.In thesesolutions,the mass density and pressure increase first from zero at the inner radius to a peak and then decrease to zero at the outerradius.With the change of the void boundary,the mass and particle number of the star can approach infinity.Neutron stars withlarge masses can remain stable and do not collapse into black holes.

Nanoparticle distribution in a rotating curved pipe considering coagulation and dispersion

We study the evolution of the particle number concentration, mass concentration, particle polydispersity, particle diameter and geometric standard deviation considering particle coagulation and dispersion in a rotating curved pipe at different Reynolds number, Schmidt number and F number. It is found that, when the Coriolis force and the centrifugal force point to the same direction, particles concentrate near the outside edge of the pipe, which becomes more obvious as time goes by. The particle number and mass concentration increase faster at the early stage than that at the later stage, and approach a stable value finally. As the coagulation proceeds, the particle diameter, polydispersity and geometric standard deviation increase and have high values in the region close to the outside edge of the pipe. When the Coriolis force and the centrifugal force point to the oppo- site direction and the Coriolis force is more dominant than the centrifugal force, particles concentrate near the inside edge of the pipe. The particles in the region with a high number concentration have high mass concentration, large diameter and high polydispersity as well as large geometric standard deviation. The particle distribution is dependent on the balance of the pipe curvature and rotating speed. The Reynolds number and the Schmidt number have effects on the particle distribution when other parameters remain unchanged. An increase in the Reynolds number leads to an increase in particle number concentration and mass concentration, and a decrease in particle polydispersity, particle diameter and geometric standard deviation. With the increase of Schmidt number the particle number concentration and mass concentration increase, and the particle polydispersity, particle diameter and geometric standard deviation decrease.

Characteristics and geometry optimization of a hollow cone for guiding and focusing laser light

A highly focused beam with spot radius of around 1 ktm and enhanced light intensity is obtained by using an open hollow cone. Two-dimensional and three-dimensional finite-difference time-domain simulations are performed for clarifying light propagation characteristics and the cone geometry dependence of the cone-focused laser light. Two important parameters characterizing the cone-focusing effect are introduced, which are opening angle and cone tip size. By changing these parameters, the laser intensification, field spatial distribution at the cone tip and the near-field transmission can be controlled. Understanding this is quite important in designing the optimum cone shape for fast ignition and determining the basis for using hollow cone targets as devices for generating high energy charged particles.