Measurement and characterization of bulk nanobubbles by nanoparticle tracking analysis method

The size of the bulk nanobubbles(typically 100 nm-200 nm in diameter)is below the optical resolution of the typical microscopes,which makes it difficult to make a direct observation of them and differentiate between the nanoparticles and the nanobubbles.In this work,a nanoparticle tracking analysis(NTA)system is developed for tracking and sizing the bulk nanobubbles,and more broadly,the Brownian diffusing particles.We demonstrate the capabilities of the NTA in characterizing the nanoparticles through systematic validation of accuracy and resolution.We particularly exhibit its unique advantages in detecting the polydisperse nanoparticle populations.Then the nucleation and the thermodynamic stability of the bulk nanobubbles are systematically studied by the NTA system.The bulk nanobubbles smaller than 600 nm in size are generated via the ultrasonication method.It is shown that both the ultrasonic cavitation treatment time and amplitude,essentially,the energy input,favor the nucleation of the bulk nanobubbles with a more concentrated size distribution,a higher concentration,and a smaller hydrodynamic size.The temperature dependence of the bulk nanobubbles over a wide range from 25°C to 70°C is explored.It is found that the nanobubble first shrinks in size significantly and then the size keeps approximately constant with the increasing temperature,showing a narrow size distribution.The transition temperature is around 45°C.Further,as an open system,the NTA is a potential tool in the study of the dynamic behavior of the bulk nanobubbles in situ,such as the coalescence and the collapse.

NOVEL METHOD FOR ERROR ANALYSIS AND SELF-CALIBRATION OF LASER TRACKING MIRROR MECHANISM

Laser tracking system （LTS） is an advanced device for large size 3D coordinates measuring with the advantages of broad range, high speed and high accuracy. However, its measuring accuracy is highly dominated by the geometric errors of the tracking mirror mechanism. Proper calibration of LTS is essential prior to the use of it for metrology. A kinematics model that describes not only the motion but also the geometric variations of LTS is developed. Through error analysis of the proposed model, it is claimed that gimbals axis misalignments and tracking mirror center off-set are the key contributors to measuring errors of LTS. A self-calibration method is presented of calibrating LTS with planar constraints. Various calibration strategies utilizing single-plane and multiple-plane constraints are proposed for different situations. For each calibration strategy, issues about the error parameter estimation of LTS are exploded to find out in which conditions these parameters can be uniquely estimated. Moreover, these conditions reveal the applicability of the planar constraints to LTS self-calibration. Intensive studies have been made to check validity of the theoretical results. The results show that the measuring accuracy of LTS has increased by 5 times since this technique for calibration is used.

Thermal History of Rocks in the Shiwandashan Basin, Southern China: Evidence from Apatite Fission Track Analysis

Based on interpretations of the apatite fission track analysis data for 10 outcrop samples and forward modeling of confined fission track length distributions, the thermal history of rocks in the Shiwandashan basin and its adjacent area, southern China, has been qualitatively and semi quantitatively studied. The results reflect several features of the thermal history. Firstly, all the samples have experienced temperatures higher than 60-70 ℃. Secondly, the time that the basement strata (T 1 b ) on the northwestern side of the Shiwandashan basin were uplifted and exhumed to the unannealed upper crust (with a paleogeotemperature of below 60-70 ℃) is much earlier than the basement rocks ( γ 1 5) on the southeastern side of the basin. Thirdly, the thermal history of samples from the basin can be divided into six stages, i.e., the fast burial and heating stage (220-145 Ma), the transient cooling stage (145-135 Ma), the burial and heating stage (135-70 Ma), the rapid cooling stage (70-50 Ma), the relatively stable stage (50-20 Ma) and another rapid cooling stage (20 Ma to present).

Proteomics of serum exosomes identified fibulin-1 as a novel biomarker for mild cognitive impairment

Mild cognitive impairment(MCI)is a prodrome of Alzheimer’s disease pathology.Cognitive impairment patients often have a delayed diagnosis because there are no early symptoms or conventional diagnostic methods.Exosomes play a vital role in cell-to-cell communications and can act as promising biomarkers in diagnosing diseases.This study was designed to identify serum exosomal candidate proteins that may play roles in diagnosing MCI.Mass spectrometry coupled with tandem mass tag approach-based non-targeted proteomics was used to show the differentially expressed proteins in exosomes between MCI patients and healthy controls,and these differential proteins were validated using immunoblot and enzyme-linked immunosorbent assays.Correlation of cognitive performance with the serum exosomal protein level was determined.Nanoparticle tracking analysis suggested that there was a higher serum exosome concentration and smaller exosome diameter in individuals with MCI compared with healthy controls.We identified 69 exosomal proteins that were differentially expressed between MCI patients and healthy controls using mass spectrometry analysis.Thirty-nine exosomal proteins were upregulated in MCI patients compared with those in control patients.Exosomal fibulin-1,with an area under the curve value of 0.81,may be a biomarker for an MCI diagnosis.The exosomal protein signature from MCI patients reflected the cell adhesion molecule category.In particular,higher exosomal fibulin-1 levels correlated with lower cognitive performance.Thus,this study revealed that exosomal fibulin-1 is a promising biomarker for diagnosing MCI.

KINEMATICS ANALYSIS OF GUIDED CHAIN DRIVE MECHANISM WITH LINKAGES

A method of analyzing the motion of guided chain drive mechanism with linkages is presented. The method studies the output motion of a point on connecting rod including motion track, velocity and acceleration.

Formation and stability of ultrasonic generated bulk nanobubbles

Although various and unique properties of bulk nanobubbles have drawn researchers＇ attention over the last few years,their formation and stabilization mechanism has remained unsolved. In this paper, we use ultrasonic methods to produce bulk nanobubbles in the pure water and give a comprehensive study on the bulk nanobubbles properties and generation. The ultrasonic wave gives rise to constant oscillation in water where positive and negative pressure appears alternately. With the induced cavitation and presence of dissolved air, the bulk nanobubbles formed. ＂Nanosight＂（which is a special instrument that combines dynamic light scattering with nanoparticle tracking analysis） was used to analyze the track and concentration of nanobubbles. Our results show that in our experiment, sufficient bulk nanobubbles were generated and we have proven they are not contaminations. We also found nanobubbles in the ultrasonic water change in both size and concentration with ultrasonic time.

Apatite Fission Track Evidence of Uplift Cooling in the Qiangtang Basin and Constraints on the Tibetan Plateau Uplift

The Qiangtang basin is located in the central Tibetan Plateau. This basin has an important structural position, and further study of its tectonic and thermal histories has great significance for understanding the evolution of the Tibetan Plateau and the hydrocarbon potential of marine carbonates in the basin. This study focuses on low temperature thermochronology and in particular conducted apatite fission track analysis. Under constraints provided by the geological background, the thermal history in different tectonic units is characterized by the degree of annealing of samples, and the timing of major （uplift-erosion related） cooling episodes is inferred. The cooling history in the Qiangtang basin can be divided into two distinct episodes. The first stage is mainly from the late Early Cretaceous to the Late Cretaceous （69.8 Ma to 108.7 Ma）, while the second is mainly from the Middle- Late Eocene to the late Miocene （10.3 Ma to 44.4 Ma）. The first cooling episode records the uplift of strata in the central Qiangtang basin caused by continued convergent extrusion after the Bangong- Nujiang ocean closed. The second episode can be further divided into three periods, which are respectively 10.3 Ma, 22.6-26.1 Ma and 30.8-44.4 Ma. The late Oligocene-early Miocene （22.6-26.1 Ma） is the main cooling period. The distribution and times of the earlier uplift-related cooling show that the effect of extrusion after the collision between Eurasian plate and India plate obviously influenced the Qiangtang basin at 44.4 Ma. The Qiangtang basin underwent compression and started to be uplifted from the middle-late Eocene to the early Oligocene （45.0-30.8 Ma）. Subsequently, a large-scale and intensive uplift process occurred during the late Oligocene to early Miocene （26.1-22.6 Ma） and the basin continued to undergo compression and uplift up to the late Miocene （10.3 Ma）. Thus, uplift-erosion in the Qiangtang basin was intensive from 44.5 Ma to about 10 Ma. The timing of cooling in the second episode shows that the uplift of the Qiangtang basin was caused by the strong compression after the collision of the Indian plate and Eurasian plate. On the whole, the new apatite fission-track data from the Qiangtang basin show that the Tibetan Plateau started to extrude and uplift during 45-30.8 Ma. The main period of uplift and formation of the Tibetan Plateau took place about 22.6-26.1 Ma, and uplift and extrusion continued until the late Miocene （10.3 Ma）.

Seasonal and inter-annual variations of Arctic cyclones and their linkage with Arctic sea ice and atmospheric teleconnections

The seasonal and inter-annual variations of Arctic cyclone are investigated. An automatic cyclone tracking algorithm developed by University of Reading was applied on the basis of European Center for Medium-range Weather Forecasts（ECMWF） ERA-interim mean sea level pressure field with 6 h interval for 34 a period. The maximum number of the Arctic cyclones is counted in winter, and the minimum is in spring not in summer.About 50% of Arctic cyclones in summer generated from south of 70°N, moving into the Arctic. The number of Arctic cyclones has large inter-annual and seasonal variabilities, but no significant linear trend is detected for the period 1979–2012. The spatial distribution and linear trends of the Arctic cyclones track density show that the cyclone activity extent is the widest in summer with significant increasing trend in CRU（central Russia）subregion, and the largest track density is in winter with decreasing trend in the same subregion. The linear regressions between the cyclone track density and large-scale indices for the same period and pre-period sea ice area indices show that Arctic cyclone activities are closely linked to large-scale atmospheric circulations, such as Arctic Oscillation（AO）, North Atlantic Oscillation（NAO） and Pacific-North American Pattern（PNA）. Moreover,the pre-period sea ice area is significantly associated with the cyclone activities in some regions.

STATISTICAL ANALYSIS OF CYCLONE TRACKS IN WESTERN ANTARCTIC REGION

The paper shows the statistical analysis of cyclone tracks that have influence on the western Antarctic region.Based on the conditions of cyclone movement and its impact upon the weather,cyclone tracks are classified into three categories,i.e.,the track moving towards the northern tip of the Antarctic Peninsula, southern track,and northern track. Moreover,in this paper,the frequency distributions of cyclone tracks,the major tracks with higher frequencies,the original region of Antarctic cyclones and the seasonal features of Antarctic cyclones have been analyzed.The results show that there are higher cyclogeneses in summer,whereas relatively fewer cycloge- neses in winter,and cyclone numbers in transitional seasons are close to the climatological average.The analysis also shows that the moving velocity of Antarctic cyclone is about the same in winter and summer. It obviously speed up during the transitional season.

ANALYSIS OF PERIODIC CHARACTERISTICS OF ERRATIC TRACK FREQUENCY FOR TYPHOON IN SOUTH CHINA SEA AND WEST PACIFIC

Typhoons with erratic movement are studied for their annual frequency of occurrence over the South China Sea and Northwest Pacific,based on 102 years of data (1884—1985).It discovers that the years with higher fre- quency tend to get together.There are well-defined periods of 12 and 30 years,revealed with the maximum entropy method (MEM),the latter of low-frequency oscillation being clearer.

Biogeographical affinities and evolution of terrestrial fauna in the Qinghai-Tibetan Plateau and the Himalayas:a case study of Aphidomorpha

The history of the Qinghai-Tibetan Plateau and the Himalayas(QTPH)region makes it a‘living laboratory'for understanding how the Earth's abiotic evolution has shaped regional biotas.However,no studies to date have attempted to investigate general macro-scale biogeographical patterns and biogeographical affinities of the QTPH terrestrial fauna in a global context.Based on the analyses of the global distributions of QTPH Aphidomorpha species,we examined generalized distribution patterns for them and investigated the biogeographical affinities between the QTPH and other regions.Track analysis and cluster analysis of the global distributions of 298 Aphidomorpha species in the QTPH identified seven generalized biogeographical tracks and eight general distribution patterns.Both approaches detected similarly generalized distribution patterns.Four marginal areas where the generalized tracks intersect,i.e.the eastern Himalayas,the western Himalayas,the Hengduan Mountains,and the northeastern QTPH,were identified as biogeographical nodes.The generalized distribution patterns indicate the biogeographical affinities between the QTPH and other regions and suggest the complex nature of the QTPH fauna.A spatial congruence between the nodes and diversity centres detected by previous studies indicates the four marginal areas have been key areas in fauna evolution as centres for faunal exchange as well as glacial refugia.Based on the biogeographical patterns,the geological history of the QTPH and the evolutionary history of Aphidomorpha,we propose an evolutionary scenario for the evolution of the QTPH aphid fauna in which faunal exchanges,vicariance due to the uplift of geographical barriers,environmental heterogeneity and Quarternary glaciations have shaped the diversity patterns and fauna in the QTPH.

Extracellular vesicles and reproduction-promotion of successful pregnancy

Extracellular vesicles （EVs） are membrane-bound complexes secreted from cells under both physiological and pathological conditions. They contain proteins, nucleic acids and lipids and act as messengers for cell-cell communication and signalling, particularly between immune cells. EV research is a rapidly evolving and expanding field, and it appears that all biological fluids contain very large numbers of EVs; they are produced from all cells that have been studied to date, and are known to have roles in several reproductive processes. This review analyses the evidence for the role of EVs throughout human reproduction, starting with the paternal and maternal gametes, followed by the establishment and continuation of successful pregnancies, with specific focus, where possible, on the interaction of EVs with the maternal immune system. Importantly, variations within the EV populations are identified in various reproductive disorders, such as pre-term labour and pre-eclampsia.

Light scattering:A review of particle characterization applications

This review covers the progress of light scattering applications in the field of particle characterization in the past decade. The review addresses static light scattering （the measurement of scattering intensities due to light-particle interaction at various spatial locations）, dynamic light scattering （the measurement of scattering due to light-particle interaction as a function of time）, and scattering tracking analysis （the tracking of particle movement through scattering measurement）.