Large Sample Areas Research Articles

Analysis of disease profile, and medical burden by lead exposure from hospital information systems in China

BackgroundThough lead (Pb)-gasoline has been banned for decades in China, Pb continues to be a vital risk factor for various diseases. Traditional studies, without large sample size, were unable to identify explicitly the associations among Pb, its disease profile, and the related medical burden. This study was designed to investigate: 1) current status of blood Pb levels; 2) Pb-associated disease profile, medical burden, as well as impact factors.MethodsResearch subjects were patients who visited military hospitals and were required to test their blood Pb levels by doctors between 2013 and 2017. The large sample size and area coverage may, to a large extent, reveal the characteristics of Pb exposure in the whole Chinese population. Information of patients’ electronic medical records was extracted using Structured Query Language (SQL) in Oracle database. The spatial, temporal, and population distribution of their blood Pb levels were tested, to illustrate the association of Pb exposure with diseases’ profile, and medical burden. Non-parametric tests were applied to compare the differences of Pb levels among various groups.ResultsThe blood Pb concentration showed a positively skewed distribution by Kolmogorov-Smirnov test (D = 0.147, p < 0.01). The blood Pb concentration of Chinese patients was 28.36 μg/L, with the lowest blood Pb levels, 4.71 μg/L, found in patients from Guangxi Zhuang Autonomous Region, and the highest, 50 μg/L, in Yunnan province. Han Chinese patients’ Pb levels were significantly lower than other minorities groups (z-score = − 38.54, p < 0.01). Average medical cost for Pb poisoning was about 6888 CNY for Chinese patients. Pb levels of patients with malignant neoplasm of lung, 45.34 μg/L, were far higher than malignant neoplasm of other respiratory, and intrathoracic organs, 24.00 μg/L (z-score = − 2.79, p < 0.01).ConclusionsThis study reported current status of blood Pb levels for patients who once visited military hospitals, partially representing the whole Chinese population. The result shows that Pb poisoning is still imposing marked economic burdens on patients under Pb exposure. Association of Pb with lung cancer may open up new areas for Pb-induced toxicology. The research strategy may advance toxicological studies in the aspect of medical data mining.

Scanning transmission electron diffraction methods.

Scanning diffraction experiments are approaches that take advantage of many of the recent advances in technology (e.g. computer control, detectors, data storage and analysis) for the transmission electron microscope, allowing the crystal structure of materials to be studied with extremely high precision at local positions across large areas of sample. The ability to map the changing crystal structure makes such experiments a powerful tool for the study of microstructure in all its forms from grains and orientations, to secondary phases and interfaces, strain and defects. This review will introduce some of the fundamental concepts behind the breadth of the technique and showcase some of the recent developments in experiment development and applications to materials.

Quantum Hall effect of Dirac surface states of as-grown single crystal flakes in Sn0.02-Bi1.08Sb0.9Te2S without gate control

The quantum spin Hall effect (QSHE) in three-dimensional topological insulators (3D-TIs) is an important hallmark of realization of ultralow dissipative electrical transport originating from nontrivial topological surface Dirac states (TSDSs). The observation of QSHE, however, had been limited at low temperatures for thin film crystals prepared by epitaxial growth or ultrathin (nanometer-level) flakes, and the finite Fermi energy tuning was required using field effect transistor (FET) construction. Here, we show that a clear observation of QSHE with a quantized level of e2/h can be possible for high quality single crystal flakes of Sn-(Bi,Sb)2(Te,S)3 (Sn-BSTS) prepared by an exfoliation method without any gate control under FET construction. The QSHE is observed in an extremely large sample area of millimeter square at the largest thickness of micrometer and up to the highest temperature of 20 K, which is greatly superior to those reported for other 3D-TIs so far. The accurate band picture of both top and bottom topological surface states of Sn-BSTS is determined from both the QSHE and the Shubnikov-de Hass (SdH) oscillations. High quality Sn-BSTS of 3D-TIs will effectively be used for experiments targeting on science as well as many technological applications expected in the future.

Mapping the conductivity of graphene with Electrical Resistance Tomography

Electronic applications of large-area graphene films require rapid and accurate methods to map their electrical properties. Here we present the first electrical resistance tomography (ERT) measurements on large-area graphene samples, obtained with a dedicated measurement setup and reconstruction software. The outcome of an ERT measurement is a map of the graphene electrical conductivity. The same setup allows to perform van der Pauw (vdP) measurements of the average conductivity. We characterised the electrical conductivity of chemical-vapour deposited graphene samples by performing ERT, vdP and scanning terahertz time-domain spectroscopy (TDS), the last one by means of a commercial instrument. The measurement results are compared and discussed, showing the potential of ERT as an accurate and reliable technique for the electrical characterization of graphene samples.

The Lymphoma-Associated Macrophage to Hodgkin-Reed-Sternberg Cell Ratio Is a Poor Prognostic Factor in Classic Hodgkin Lymphoma Patients

BackgroundDespite the relatively high rate of curability, approximately 20% to 30% of patients with classic Hodgkin lymphoma relapse. Hodgkin-Reed-Sternberg (HRS) cells:lymphoma-associated macrophages (LAMs) cross talk promotes tumor growth and resistance to therapy. The aim of the study was to assess the prognostic role of the LAM to HRS ratio (LHR) in lymph node biopsies using a novel automated system for scanning large sample areas. Patients and MethodsHigh-quality tissue samples obtained from 71 patients and stained with anti-CD30 and anti-CD68 were analyzed using the TissueFAXS (TissueGnostics). ResultsA high LHR was associated with inferior 5-year progression-free survival (PFS; 50.0% vs. 79.3%; P = .032) and overall survival (OS; 65.4% vs. 92.3%; P = .012). Multivariate Cox regression identified the high LHR as an unfavorable prognostic factor for PFS (hazard ratio [HR], 3.07; P = .029) and OS (HR, 4.56; P = .025). ConclusionA high LHR at diagnosis is associated with a higher risk of lymphoma progression or death. Automated image analysis is a new tool that can overcome technical limitations of by microarray samples in lymphomas with high intratumor heterogeneity.

Large-area enhancement of far-field fluorescence intensity using planar nanostructures

While nanoscale local enhancement of fluorescence is a well-studied phenomenon, enhancement of far-field radiation of large-area samples using nanostructures has been explored much less. In this work, we demonstrate planar nanostructures with exceptionally high far-field intensity enhancement factors and in addition show that the enhancement can be made controllable via the polarization state of the pump light. We also find that, counterintuitively, the Purcell effect plays only a small part in the observed far-field enhancement. The results of these studies can be applied, for example, in thin-film optical emitters, fluorescence sensors, and wide-field fluorescence microscopy.

Application of large format tissue processing in the histology laboratory

ABSTRACTIn clinical, research and veterinary laboratories of North America, large format histology has more recently been improved with newer equipment and better methodology. Large tissue specimens are frequently sliced in the grossing room and processed in multiple smaller, standard size tissue cassettes. Justifiably, submitting more blocks inherently lends itself to a greater confidence in the accuracy of the diagnosis, yet guidelines for tissue sampling often suggest taking fewer samples. For example, large tumor specimen protocols recommend taking one standard-sized tissue block for each cm diameter of tumor. However, cancers are the culmination of many complex changes in cell metabolism and often appear dissimilar at different tissue locations. As these changes have an uncertain behavior, many other tissue samples are often taken from areas that appear to have either a variable texture or color. Consequently, at microscopy, the complete tissue sample may need to be reassembled like a jigsaw puzzle as the stained sections are frequently presented over many slides. This problem has easily been overcome by using large format cassettes since the entire cross-section of the tissue sample can often be viewed on a single slide. Because these cassettes can effectively hold up to 10 times the volume of conventional standard size cassettes, they are a more efficient way of assessing large areas of tissue samples. This system is easily adapted for all tissue types and has become the established method for assessing large tissue samples in many laboratory settings.

Phase field modeling of domain dynamics and polarization accumulation in ferroelectric HZO

In this work, we investigate the accumulative polarization (P) switching characteristics in ferroelectric (FE) thin films under the influence of sequential sub-coercive electric-field pulses. Performing the dynamic phase-field simulation (based on time-dependent Landau-Ginzburg model) and experimental measurement on Hf0.4Zr0.6O2 (HZO), we analyze the electric field induced domain-wall (DW) motion and the resultant P accumulation process in FE. According to our analysis, even in the absence of an applied electric field, the DW can potentially undergo spontaneous motion. Such a DW instability leads to spontaneous P-excitation and relaxation processes, which play a pivotal role in accumulative P-switching in an FE grain. We show that the extent of such P accumulation increases with the increase in the applied electric field, increase in excitation time and decrease in relaxation time. Finally, by considering an ensemble of grains with local and global coercive field distributions, we model the P-accumulation process in a large area HZO sample. In such a multi-grain scenario, the dependency of P accumulation on the applied electric field pulse attributes follows similar features as that of a single-grain, although the spontaneous processes (excitation/relaxation) are less prominent in large area sample.

Preparation Methods for Scanning Electron Microscope Characterization of Nano-Carbides in Cold Work Steel X153CrMoV12

Abstract The suitability of different preparation methods for imaging nano-carbides by scanning electron microscopy (SEM) was evaluated taking the example of cold work steel X153CrMoV12 manufactured by powder metallurgy. The ion beam slope cutting method, carbide etching using sulfurous acid, and electrolytic polishing using the Struers electrolyte A2 were considered in this study. The preparation aim was to develop an appropriate method for the qualitative detection of nano-carbides using the SEM to characterize relatively large sample areas and to substitute time-consuming transmission electron microscope examinations. The carbide detection was performed on heat-treated samples using sulfurous acid, applying the ion beam slope cutting method, and by electrolytic polishing using the electrolyte A2. In the SEM, nano-carbides could be observed on the sample surfaces prepared by ion beam slope cutting and the electrolytically polished ones. The examinations were performed on conventionally quenched and tempered material samples of cold work steel X153CrMoV12 (reference condition) as well as on samples subjected to deep cryogenic treatment (DCT). Deep cryogenic treated samples showed a significantly increased number of nano-carbides.

Optimization of Ethylene Glycol Doped PEDOT:PSS Transparent Electrodes for Flexible Organic Solar Cells by Drop-coating Method

Fabrication of flexible transparent electrodes (FTEs) is one of the core technologies in the field of flexible electronics. Among multiple choices of FTEs, poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonic acid) (PEDOT:PSS) has shown its promising application in roll-to-roll manufacturing. A simple yet effective method for substantially boosting the conductivity of these conducting polymer films without causing large-domain aggregations is by adding ethylene glycol (EG) as dopant. Herein, we investigated in detail the effects of the secondary solvent of ethylene glycol (EG) on the optical and electrical characteristics of PEDOT:PSS films. The modified PEDOT:PSS FTEs were deposited using drop-coating techniques as it had greater compatibility for large-area samples than the conventional spin-coating method did. The 6% EG-doped PEDOT:PSS FTE via drop-coating method achieved a high figure of merit (FoM) value of 47.24 and the devices fabricated using the optimal PEDOT:PSS FTE yielded a high power conversion efficiency (PCE) of 8.89%, mostly attributed to the modified PEDOT:PSS films that had excellent optical and electrical characteristics with low surface roughness. These results suggested that EG-doping could effectively boost the conductivity of PEDOT:PSS films and that the modified PEDOT:PSS FTE is suitable for roll-to-roll manufacturing in the future.

Roadside collection of training data for cropland mapping is viable when environmental and management gradients are surveyed

Cropland maps derived from satellite imagery have become a common source of information to estimate food production, support land use policies, and measure the environmental impacts of agriculture. Cropland classification models are typically calibrated with data collected from roadside surveys which enable the sampling of large areas at a relatively low cost. However, there is a risk of providing biased data as environmental and management gradients may not be fully captured from road networks, thereby violating the assumption of representativeness of calibration data. Despite being widely adopted, the potential biases of roadside sampling have so far not been thoroughly addressed. In this study, we looked for evidence of these biases by comparing three sampling strategies: Random sampling, Roadside sampling, and Transect sampling – a spatially constrained variant of Roadside sampling. In these three strategies, non-cropland data are randomly distributed as they can be photo-interpreted. Based on reference maps at 30 m in four study sites, we followed a Monte Carlo approach to generate multiple realizations of each sampling strategy for ten sample sizes. The effect of the sampling strategy was then assessed in terms of representativeness of the data set collected and accuracy of the resulting maps. Results showed that data sets obtained from Roadside sampling were significantly less representative than those obtained from Random sampling but the resulting maps were only marginally less accurate (2% difference). Transect sampling captured systematically less variability than Random or Roadside sampling which led to differences in accuracy as large as 15%. The effect of sample size on accuracy varied across sites but generally leveled off after reaching 3000 pixels. Augmenting the size of Transect samples improved the classification accuracy but not sufficiently to match the performance of the other sampling strategies. Finally, we found that Random and Roadside training sets with similar representativeness yield comparable accuracy. Therefore, we conclude that roadside sampling can be a viable source of training data for cropland mapping if the range of environmental and management gradients is surveyed. This underlines the importance of survey planning to identify those routes that capture most variability.

Measurement of carrier lifetime in micron-scaled materials using resonant microwave circuits

The measurement of minority carrier lifetimes is vital to determining the material quality and operational bandwidth of a broad range of optoelectronic devices. Typically, these measurements are made by recording the temporal decay of a carrier-concentration-dependent material property following pulsed optical excitation. Such approaches require some combination of efficient emission from the material under test, specialized collection optics, large sample areas, spatially uniform excitation, and/or the fabrication of ohmic contacts, depending on the technique used. In contrast, here we introduce a technique that provides electrical readout of minority carrier lifetimes using a passive microwave resonator circuit. We demonstrate >105 improvement in sensitivity, compared with traditional photoemission decay experiments and the ability to measure carrier dynamics in micron-scale volumes, much smaller than is possible with other techniques. The approach presented is applicable to a wide range of 2D, micro-, or nano-scaled materials, as well as weak emitters or non-radiative materials.

Basal slip mediated tension twin variant selection in magnesium WE43 alloy

Tension twinning nucleation and evolution in Mg WE43 alloy over a large sampling area was investigated using a quasi-in-situ EBSD/SEM method during interrupted compression testing. The results showed tension twins with both high and low macroscopic Schmid factor (MSF) were activated under a compressive stress of 100 MPa with a strain rate of 10−1 s−1. Basal slip in most grains dominated at this stress, so nucleation of twin variants required little interaction with non-basal slip, which was different from other studies that reported prismatic slip and/or tension twinning were required to activate some low MSF tension twin variants. The geometric compatibility factor (m') was demonstrated to be an important factor to determine tension twin variant selection assisted by basal slip. The analysis indicated m' played a critical role over MSF in tension twin variant selection during twin nucleation stage, and final twin variant types were insensitive to increasing stress, but they inherited twin variant types determined at twin nucleation stage. Moreover, which specific grain boundary of a grain with hard orientation for basal slip would nucleate which twin variant could be also validated by m' and largely depended on two factors: (a) high value of m' with 1st or 2nd rank between the tension twinning of nucleated twin variant and basal slip in adjoining grains; and (b) intensive basal slip activity in the neighbouring grains before twin nucleation.

Characterization of New Sustainable Acoustic Solutions in a Reduced Sized Transmission Chamber

In order to assess the airborne sound insulation of a new material or building solution, access to standardized laboratories, large and expensive facilities, and a sample area of at least 10 m2 are required. At the research and development stages of new sustainable acoustic materials for construction, it is not easy to make large sample areas available. Moreover, the financial investment in acoustic testing of materials during the research stage in standardized laboratories is excessive. In this work, the assessment of the airborne sound insulation of multi-layer partitions designed with new sustainable materials is presented. The assessed solutions are formed by green composite fiber boards as lightweight elements and a new material designed from sheep wool as absorbent material. The results of these 100% recyclable solutions are compared with lightweight element based solutions, which are commonly used for acoustic insulation. Characterization of those new sustainable solutions for building is leveraged in a reduced sized transmission chamber. The design, construction, and validation of this kind of laboratory are provided. This laboratory enables the assessment of the airborne sound insulation of a material in its research stage.

Evolution of the Stellar Mass Function and Infrared Luminosity Function of Galaxies since z = 1.2

Abstract We measured evolution of the K-band luminosity function and stellar mass function (SMF) for red and blue galaxies at z &lt; 1.2 using a sample of 353 594 I &lt; 24 galaxies in 8.26 square degrees of Boötes. We addressed several sources of systematic and random error in measurements of total galaxy light, photometric redshift, and absolute magnitude. We have found that the K-band luminosity density for both red and blue galaxies increased by a factor of 1.2 from z ∼ 1.1 to z ∼ 0.3, while the most luminous red (blue) galaxies decreased in luminosity by 0.19(0.33) mag or ×0.83(0.74). These results are consistent with z &lt; 0.2 studies, while our large sample size and area result in smaller Poisson and cosmic variance uncertainties than most z &gt; 0.4 luminosity and mass function measurements. Using an evolving relation for K-band mass-to-light ratios as a function of (B−V) color, we found a slowly decreasing rate of growth in red galaxy stellar mass density of ×2.3 from z ∼ 1.1 to z ∼ 0.3, indicating a slowly decreasing rate of migration from the blue cloud to the red sequence. Unlike some studies of the SMF, we find that massive red galaxies grow by a factor of ×1.7 from z ∼ 1.1 to z ∼ 0.3, with the rate of growth due to mergers decreasing with time. These results are comparable with measurements of merger rates and clustering, and they are also consistent with the red galaxy stellar mass growth implied by comparing K-band luminosity evolution with the fading of passive stellar population models.

Structural Basis for the Lipid-Mediated Interaction of Tubulin with VDAC Revealed by Neutron Reflectometry

A preponderance of evidence suggests that the mitochondrial outer membrane (MOM) binds dimeric tubulin, which blocks the flux of metabolites through VDAC, the major MOM channel, by inserting its negatively charged, disordered C-terminal tail into the VDAC pore. The discovery of this novel regulatory mechanism of mitochondrial respiration has raised several fundamental questions, including how tubulin binds to the MOM surface, whether its membrane-bound conformation is consistent with the accessibility of its C-termini to the membrane surface, and what role mitochondrial lipids assume in mediating the tubulin-VDAC interaction. Here we report neutron reflectivity (NR) studies on tubulin-coated and VDAC-containing biomimetic membranes. In combination with molecular dynamics simulations, these reveal, first, that dimeric tubulin is anchored to the membrane surface by an amphipathic a-helix of the a-tubulin subunit in an orientation that presents the C-termini of both tubulin subunits to the membrane surface. The structural model is supported by electrophysiological evidence using recombinant tubulin constructs in which C-terminal tails bound to either subunit are individually observed in a VDAC nanopore. Second, we demonstrate using NR that surface-immobilized VDAC can be reconstituted into a complete lipid membrane, thus creating a “protein-tethered bilayer lipid membrane” (ptBLM) over a large sample area. The ptBLM architecture allows dynamic changes of the solution environment, while NR reveals the corresponding structural response of the protein and its lipid environment. This allows us to experimentally observe the effects of pH-induced changes in VDAC's structure on the local lipid environment. Molecular dynamics simulations are in good agreement with NR experiments. We speculate that local curvature or lipid packing stress induced by membrane-embedded VDAC and its structural dynamics serves to localize cytosolic regulators such as tubulin to the vicinity of the channel.

Hyperspectral Imaging in Scattering Media using Two Filters

Hyperspectral imaging is a common technique in fluorescence microscopy to obtain the emission spectrum at each pixel of an image. However, methods to obtain spectral resolution based on diffraction gratings or integrated prisms work poorly when the sample is strongly scattering. We developed a microscope named the DIVER that collects the fluorescence emission over a very large angle and sample area. We have shown that this microscope, depending on the tissue thickness, can capture several orders of magnitude more light than conventional microscopes using epi detection, which in turn significantly increases imaging depth. Since the fluorescence light after passing through the multiple scattering sample is not collimated, the use of grating or prisms strongly limits the amount of light that can be used with available hyperspectral devices. Here we show that two filters that accept uncollimated light over a large aperture are sufficient to calculate the spectral phasor rather than displaying the entire spectrum. Using the properties of the spectral phasors we can resolve spectral components and perform the type of data analyses that are usually performed in hyperspectral image analysis. (Supported in part by the NIH grant NIH P41-GM103540).

Antiscattering X-ray fluorescence analysis for large-area samples

The scattering background in large-area X-ray fluorescence analysis (more than one square centimeter) has been greatly reduced by using highly polarized X-rays and by inserting a collimator plate between the sample and the detector.

Multi-Beam Scanning Electron Microscopy for High-Throughput Imaging in Connectomics Research.

Major progress has been achieved in recent years in three-dimensional microscopy techniques. This applies to the life sciences in general, but specifically the neuroscientific field has been a main driver for developments regarding volume imaging. In particular, scanning electron microscopy offers new insights into the organization of cells and tissues by volume imaging methods, such as serial section array tomography, serial block-face imaging or focused ion beam tomography. However, most of these techniques are restricted to relatively small tissue volumes due to the limited acquisition throughput of most standard imaging techniques. Recently, a novel multi-beam scanning electron microscope technology optimized to the imaging of large sample areas has been developed. Complemented by the commercialization of automated sample preparation robots, the mapping of larger, cubic millimeter range tissue volumes at high-resolution is now within reach. This Mini Review will provide a brief overview of the various approaches to electron microscopic volume imaging, with an emphasis on serial section array tomography and multi-beam scanning electron microscopic imaging.

Enhanced Desorption Electrospray Ionization Mass Spectrometry via Synchronizing Ion Generation and Ion Injection.

A modified version of desorption electrospray ionization mass spectrometry was developed for (i) better utilization of analyte ions and (ii) larger sampling area via synchronization the pulsed nebulizer gas with ion injection. To synchronize the sheath gas, gas flow was paused for 50ms within each cycle, leading to solvent accumulation at the end of emitter tip. That solvent accumulation enlarged the desorption areas. As a result, the amount of analytes increased. Thus, the improved signal intensity (~ 2-5-folds for various substrates) was benefit from both better analyte ion utilization and larger desorption areas. Finally, the enhanced signal intensity was confirmed with both garlic homogenate and brain homogenate. Graphical Abstract ᅟ.