Scattering Properties Research Articles

Methods & Protocols of 2020

RETURN TO ISSUEPREVEditorialNEXTMethods & Protocols of 2020Carlos Toro*Carlos Toro*(C.T.) Email: [email protected]More by Carlos Torohttp://orcid.org/0000-0002-8359-462X and Sara E. Skrabalak*Sara E. Skrabalak*(S.E.S.) Email: [email protected]More by Sara E. Skrabalakhttp://orcid.org/0000-0002-1873-100XCite this: Chem. Mater. 2021, 33, 5, 1509–1512Publication Date (Web):March 9, 2021Publication History Published online9 March 2021Published inissue 9 March 2021https://doi.org/10.1021/acs.chemmater.1c00551Copyright © 2021 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views626Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (4 MB) Get e-AlertsSUBJECTS:Scattering,Safety,Physical and chemical properties,Spectroscopy,Materials Get e-Alerts

The Scattering Properties of Gaseous Parahydrogen

In this work, the scattering properties of parahydrogen gas (p-H2) are studied in the temperature-range (1–50) K. These properties are investigated within the framework of the Lippmann–Schwinger formalism for p-H2. This formalism is used to calculate the phase shifts. The calculations are undertaken using Silvera-Goldman potential. The scattering properties of the system—the total, viscosity, and average cross sections—are then computed using these phase shifts. The s-wave scattering length for p-H2 molecules $$a_{o}$$ is determined as $$a_{o}$$ = 7.01 A. The cross sections exhibited the Ramsauer–Townsend effect and resonance peaks. The lifetime of the quasi-bound states for $$\ell - wave$$ $$\left( {\ell = {2,}\,{\text{4, and 6}}} \right)$$ is also computed.

Numerical Simulation of Lunar Seismic Wave Propagation: Investigation of Subsurface Scattering Properties Near Apollo 12 Landing Site

AbstractOne of the most critical issues associated with the analysis of lunar seismic data is the intense scattering, which prevents precise seismic phase identifications, thereby resulting in poor constraints on the internal structure of the Moon. Although some studies estimated subsurface scattering properties from analyses of the Apollo seismic data, the properties have large uncertainties and are still open issues to be resolved to improve the inner structure model of the Moon. While the previous studies tried to constrain the scattering features within the lunar crust mainly from data analysis, this study estimated them from a numerical approach. We constrained the scattering properties near Apollo 12 landing site by conducting seismic wave propagation simulations under various parameter settings and comparing the synthetics with the data. As a result, we succeeded in reproducing seismic signals excited by the Apollo artificial impacts. This led to a constraint on the scattering properties, such as typical scale and thickness of heterogeneity, around the Apollo 12 landing site. The derived structure suggests that the intense scattering structure exists down to 20 km at the northern portion of the region of the Apollo 12 landing site, and to 10 km at the southern region from the landing site. In addition, our model requires a smaller P‐ and S‐wave velocity ratio (1.2–1.4) compared with those conventionally considered (>1.73). This implies a dry and porous environment consistent with laboratory measurements of terrestrial samples and reasonable with the generalized lunar environment.

Chromosome analysis and sorting.

Flow cytometric analysis and sorting of plant mitotic chromosomes has been mastered by only a few laboratories worldwide. Yet, it has been contributing significantly to progress in plant genetics, including the production of genome assemblies and the cloning of important genes. The dissection of complex genomes by flow sorting into the individual chromosomes that represent small parts of the genome reduces DNA sample complexity and streamlines projects relying on molecular and genomic techniques. Whereas flow cytometric analysis, that is, chromosome classification according to fluorescence and light scatter properties, is an integral part of any chromosome sorting project, it has rarely been used on its own due to lower resolution and sensitivity as compared to other cytogenetic methods. To perform chromosome analysis and sorting, commercially available electrostatic droplet sorters are suitable. However, in order to resolve and purify chromosomes of interest the instrument must offer high resolution of optical signals as well as stability during long runs. The challenge is thus not the instrumentation, but the adequate sample preparation. The sample must be a suspension of intact mitotic metaphase chromosomes and the protocol, which includes the induction of cell cycle synchrony, accumulation of dividing cells at metaphase, and release of undamaged chromosomes, is time consuming and laborious and needs to be performed very carefully. Moreover, in addition to fluorescent staining chromosomal DNA, the protocol may include specific labelling of DNA repeats to facilitate discrimination of particular chromosomes. This review introduces the applications of chromosome sorting in plants, and discusses in detail sample preparation, chromosome analysis and sorting to achieve the highest purity in flow‐sorted fractions, and their suitability for downstream applications.

Assessment of the COVID-19 Lockdown Effects on Spectral Aerosol Scattering and Absorption Properties in Athens, Greece

COVID-19 is evolving into one of the worst pandemics in recent history, claiming a death toll of over 1.5 million as of December 2020. In an attempt to limit the expansion of the pandemic in its initial phase, nearly all countries imposed restriction measures, which resulted in an unprecedented reduction of air pollution. This study aims to assess the impact of the lockdown effects due to COVID-19 on in situ measured aerosol properties, namely spectral-scattering (bsca) and absorption (babs) coefficients, black carbon (BC) concentrations, single-scattering albedo (SSA), scattering and absorption Ångström exponents (SAE, AAE) in Athens, Greece. Moreover, a comparison is performed with the regional background site of Finokalia, Crete, for a better assessment of the urban impact on observed differences. The study examines pre-lockdown (1–22 March 2020), lockdown (23 March–3 May 2020) and post-lockdown (4–31 May 2020) periods, while the aerosol properties are also compared with a 3–4 year preceding period (2016/2017–2019). Comparison of meteorological parameters in Athens, between the lockdown period and respective days in previous years, showed only marginal variation, which is not deemed sufficient in order to justify the notable changes in aerosol concentrations and optical properties. The largest reduction during the lockdown period was observed for babs compared to the pre-lockdown (−39%) and to the same period in previous years (−36%). This was intensified during the morning traffic hours (−60%), reflecting the large decrease in vehicular emissions. Furthermore, AAE increased during the lockdown period due to reduced emissions from fossil-fuel combustion, while a smaller (−21%) decrease was observed for bsca along with slight increases (6%) in SAE and SSA values, indicating that scattering aerosol properties were less affected by the decrease in vehicular emissions, as they are more dependent on regional sources and atmospheric processing. Nighttime BC emissions related to residential wood-burning were slightly increased during the lockdown period, with respect to previous-year means. On the contrary, aerosol and pollution changes during the lockdown period at Finokalia were low and highly sensitive to natural sources and processes.

Self-Assembled Black Phosphorus-Based Composite Langmuir-Blodgett Films with an Enhanced Photocurrent Generation Capability and Surface-Enhanced Raman Scattering Properties.

In this work, Langmuir–Blodgett (LB) composite thin films were successfully prepared using black phosphorus nanosheets (BPNS) and dye molecules. Black phosphorus (BP) was first exfoliated in isopropanol solution to form BPNS, and then, BPNS were modified with 4-azidobenzoic acid (Az-BPNS) to improve their stability. The characterization results showed that the synthesized Az-BPNS-dye LB films have a uniform and ordered structure. In addition, the synthesized Az-BPNS-dye LB films exhibit excellent photoelectrochemical performance, and Az-BPNS-methylene blue (MB) produces higher photocurrent compared to Az-BPNS-Neutral red (NR) films. The current work shows an effective way to prepare functionalized BP-based materials and provide evidence for their application in optoelectronic devices.

Meta‐microstructures: Programmable Controls to Scattering Properties of a Radiation Array (Laser Photonics Rev. 15(2)/2021)

In article number 2000449, Si Jia Li, Tie Jun Cui, and co-workers develop a new type of meta-microstructure by combining a programmable metasurface with a radiation array, which can manipulate the scattering properties, digitally and in real-time, and exhibit different radiation modes simultaneously. This technique is to be particularly useful in stealth aircraft systems and the multi-function device of wireless communications.

Programmable Controls to Scattering Properties of a Radiation Array

AbstractElectromagnetic (EM) waves have been widely applied in wireless communications, radar detection, navigation, and target recognition. Radiation and scattering are two common behaviors in the EM community, but it remains a long‐standing challenge to control them in a dynamical way, especially using a single, low‐cost, and compact hardware. Here, a promising solution is proposed by combining a programmable metasurface with a radiation array, which can manipulate the scattering properties, digitally and in real‐time, and exhibit different radiation modes simultaneously. More advantageous over previous investigations with the fixed radiation‐scattering performance, a field‐programmable gate array is introduced to extend, realize, and verify the multiple functions of the meta‐microstructure (MMS). As a proof‐of‐concept, multiple functions, including polarization conversion, scattering beam manipulation, diffusion scattering, radar cross‐section reduction, EM waves radiation, and vortex beam generation, have been adequately demonstrated by the MMS prototype.

Friedel Oscillations Induced by Magnetic Skyrmions: From Scattering Properties to All-Electrical Detection.

Magnetic skyrmions are spin swirling solitonic defects that can play a major role in information technology. Their future in applications and devices hinges on their efficient manipulation and detection. Here, we explore from ab-initio their nature as magnetic inhomongeities in an otherwise unperturbed magnetic material, Fe layer covered by a thin Pd film and deposited on top of Ir(111) surface. The presence of skyrmions triggers scattering processes, from which Friedel oscillations emerge. The latter mediate interactions among skyrmions or between skyrmions and other potential surrounding defects. In contrast to their wavelengths, the amplitude of the oscillations depends strongly on the size of the skyrmion. The analogy with the scattering-off atomic defects enables the assignment of an effective scattering potential and a phase shift to the skyrmionic particles, which can be useful to predict their behavior on the basis of simple scattering frameworks. The induced charge ripples can be utilized for a noninvasive all-electrical detection of skyrmions located on a surface or even if buried a few nanometers away from the detecting electrode.

Numerical Simulation on Spatial-Frequency Domain Imaging for Estimating Optical Absorption and Scattering Properties of Two-Layered Horticultural Products

Spatial-frequency domain imaging (SFDI) is a wide-field, noncontact, and label-free imaging modality that is currently being explored as a new means for estimating optical absorption and scattering properties of two-layered turbid materials. The accuracy of SFDI for optical property estimation, however, depends on light transfer model and inverse algorithm. This study was therefore aimed at providing theoretical analyses of the diffusion model and inverse algorithm through numerical simulation, so as to evaluate the potential for estimating optical absorption and reduced scattering coefficients of two-layered horticultural products. The effect of varying optical properties on reflectance prediction was first simulated, which indicated that there is good separation in diffuse reflectance over a large range of spatial frequencies for different reduced scattering values in the top layer, whereas there is less separation in diffuse reflectance for different values of absorption in the top layer, and even less separation for optical properties in the bottom layer. To implement the nonlinear least-square method for extracting the optical properties of two-layered samples from Monte Carlo-generated reflectance, five curve fitting strategies with different constrained parameters were conducted and compared. The results confirmed that estimation accuracy improved as fewer variables were to be estimated each time. A stepwise method was thus suggested for estimating optical properties of two-layered samples. Four factors influencing optical property estimation of the top layer, which is the basis for accurately implementing the stepwise method, were investigated by generating absolute error contour maps. Finally, the relationship between light penetration depth and spatial frequency was studied. The results showed that penetration depth decreased with the increased spatial frequency and also optical properties, suggesting that appropriate selection of spatial frequencies for a stepwise method to estimate optical properties from two-layered samples provides potential for estimation accuracy improvement. This work lays a foundation for improving optical property estimation of two-layered horticultural products using SFDI.

The Effect of Drop Shape, Sensing Volume and Raindrop Size Statistics to the Scattered Field on 300 GHz

Scattering and attenuation properties of rain using various drop models are calculated using Mie theory, the T-matrix method and numerical technique respectively. Ellipsoidal and oblate drops use the axis ratio of raindrops reported in literature. Scattering are presented both for small volumes containing a single drop and for large volumes with multiple drops in which the statistics of drop size distribution need to be taken into account. The angular dependence of scattering, absorption and scattering cross sections and polarization ratios are investigated. For single scattering the angular dependence and cross sections of nonspherical drops differed from those of a spherical drop. Differences between ellipsoid and oblate drops were minimal. Drop shape affected the polarization mostly at 40-140 degree detection angles. The averaged linear attenuation and rain induced cross channel signal were studied. Attenuation was close to the ITU-R.838 model and in the same order of magnitude as the attenuation due to atmospheric moisture. The cross channel signal was calculated as a function of rain rate and transmitter/receiver angle. Vertical polarization was observed to produce a higher cross channel signal than horizontal polarization. It was concluded that drop shape is not an important factor at 300 GHz due to small drops dominating the scattering signal. Overall, the results showed that in single scattering, the ellipsoid is a good approximation for raindrops and that for large volumes, a spherical drop approximation and a Mie solution may be sufficient at frequencies of 300 GHz and higher.

Use of a convolutional neural network and quantitative ultrasound for diagnosis of fatty liver

Quantitative ultrasound (QUS) was used to classify rabbits that were induced to have liver disease by placing them on a fatty diet for a defined duration and/or periodically injecting them with CCl4. The ground truth of the liver state was based on lipid liver percents estimated via the Folch assay and hydroxyproline concentration to quantify fibrosis. Rabbits were scanned ultrasonically in vivo using a SonixOne scanner and an L9-4/38 linear array. Liver fat percentage was classified based on the ultrasonic backscattered radiofrequency (RF) signals from the livers using either QUS or a 1-D convolutional neural network (CNN). Use of QUS parameters with linear regression and canonical correlation analysis demonstrated that the QUS parameters could differentiate between livers with lipid levels above or below 5%. However, the QUS parameters were not sensitive to fibrosis. The CNN was implemented by analyzing raw RF ultrasound signals without using separate reference data. The CNN outputs the classification of liver as either above or below a threshold of 5% fat level in the liver. The CNN outperformed the classification utilizing the QUS parameters combined with a support vector machine in differentiating between low and high lipid liver levels (i.e., accuracies of 74% versus 59% on the testing data). Therefore, although the CNN did not provide a physical interpretation of the tissue properties (e.g., attenuation of the medium or scatterer properties) the CNN had much higher accuracy in predicting fatty liver state and did not require an external reference scan.

Optical Absorption and Scattering Properties at 900-1650 nm and Their Relationships with Soluble Solid Content and Soluble Sugars in Apple Flesh during Storage.

Soluble solid content (SSC) is regarded as the most significant internal quality associated with the taste and maturity in fruits. Evaluating the relationship between the optical properties and soluble sugars facilitates exploration of the mechanism of optical techniques in SSC assessment. In this research, absorption coefficient (μa) and reduced scattering coefficient (μ′s) of Fuji apple during storage were obtained using automatic integrating sphere (AIS) at 905–1650 nm. Relationships between μa, μ′s and SSC, and soluble sugars contents, were investigated. The result showed that SSC, the content of total soluble sugars (TSS), fructose, glucose and sucrose were all decreasing after storage, and the same trend appeared in the change of μa and μ′s. In the whole wavelength range, both μa and μ′s were positively related to SSC and soluble sugars contents. The correlations between μa and SSC, and soluble sugars contents, showed increasing tendencies with increasing wavelengths, while for μ′s, correlations had the opposite trend. The strongest correlations between μa and SSC, and soluble sugars contents, were observed in the correlation of μa with sucrose, with an r of 0.934. Furthermore, a partial least square (PLS) model for sucrose based on μa was built with the coefficient of determination of prediction (Rp2) and the root mean square error of prediction (RMSEP) of 0.851 and 1.047, respectively. The overall results demonstrate that optical properties at the range of 905–1650 nm could be used to evaluate SSC of apples and this may due to the strong correlation between sucrose content and μa.

Early Phases of COVID-19 Are Characterized by a Reduction in Lymphocyte Populations and the Presence of Atypical Monocytes.

BackgroundSevere acute respiratory syndrome coronavirus 2 is a recently discovered pathogen responsible of coronavirus disease 2019 (COVID-19). The immunological changes associated with this infection are largely unknown.MethodsWe evaluated the peripheral blood mononuclear cells profile of 63 patients with COVID-19 at diagnosis. We also assessed the presence of association with inflammatory biomarkers and the 28-day mortality.ResultsLymphocytopenia was present in 51 of 63 (80.9%) patients, with a median value of 720 lymphocytes/µl (IQR 520-1,135). This reduction was mirrored also on CD8+ (128 cells/µl, IQR 55-215), natural killer (67 cells/µl, IQR 35–158) and natural killer T (31 cells/µl, IQR 11–78) cells. Monocytes were preserved in total number but displayed among them a subpopulation with a higher forward and side scatter properties, composed mainly of cells with a reduced expression of both CD14 and HLA-DR. Patients who died in the 28 days from admission (N=10, 15.9%), when compared to those who did not, displayed lower mean values of CD3+ (337.4 cells/µl vs 585.9 cells/µl; p=0.028) and CD4+ cells (232.2 cells/µl vs 381.1 cells/µl; p=0.042) and an higher percentage of CD8+/CD38+/HLA-DR+ lymphocytes (13.5% vs 7.6%; p=0.026).DiscussionThe early phases of COVID-19 are characterized by lymphocytopenia, predominance of Th2-like lymphocytes and monocytes with altered immune profile, which include atypical mononuclear cells.

Studying Immunophenotypic Modulation at Different Time Points of Chemotherapy : A Walk through the Disease Course in 121 Pediatric B Lymphoblastic Leukemia Cases; Providing Implications for MRD Detection

Introduction Disease monitoring in management of acute leukemia is essentially important in terms of risk stratification and assessing response to chemotherapy throughout the disease course for which minimal residual disease (MRD) testing is the most reliable tool. Measurement of MRD by flow cytometry is based on the principle of studying difference in antigenic expression of the leukemic cells, hematogones and residual normal B cells. Modulation of antigen expression is an established fact that occurs on leukemic blasts during treatment under the influence of chemotherapeutic drugs, which may cause difficulty in analysis and detection of MRD [H.Burnusuzov et al. Folia Medica 2016;58(1):28-35]. Literature has reported antigen expression modulation, particularly during the glucocorticoid phase of induction therapy [Dworzak et al. Cytometry Part B 2010; 78B: 147-153]. For MRD assessment, such phenotypic shifts pose a particular challenge since they can cause misinterpretations and false results. However to our knowledge there hasn't been a large cohort studied to map antigenic modulation and analyze similar antigenic trends in comparison between leukemic blasts and non-leukemic B cells which may coexist during different phases of chemotherapy. Key words: B-lymphoblastic leukemia, Flowcytometry, Antigen modulation, Minimal residual disease, Immunophenotype Methods: The study is conducted at the Hematology department of The Indus Hospital from April 2018 to March 2020. Among 445 pediatric B-lymphoblastic leukemia patients (1 month-18 years); we studied 121 patients who were MRD positive in bone marrow throughout the evaluation period. All patients received Berlin-Frankfurt-Munster (BFM) chemotherapy protocol as per National Cancer Institute (NCI) risk stratification criteria. To observe immunophenotypic modulation (IM) in antigen expression of Tdt, CD34, CD10, CD20, CD45, CD13, CD33 and CD66, compared from the time of diagnosis (day 0), post induction chemotherapy (day 35), post consolidation chemotherapy (day 52) and during maintenance chemotherapy (day78). Using eight color Flowcytometry (BD FACS CANTO-II; DIVA software version 8.0.2), the IM was assessed by comparative analyses of the changes in the mean flourescence intensity (MFI) of leukemic and non-leukemic B cells. The Wilcoxon signed rank test is used to compare median of MFI values at diagnosis and subsequent time points of MRD. Independent sample T-test/Mann-Whitney U test was applied as appropriate to determine significant differences in expression of antigens. A p-value of < 0.05 was considered as significant. Box and whisker plots and run charts will be used for descriptive purposes. Results: Mean age of the patients was 5.7years ±3.7 with male to female 1.7:1.We analyzed forward scatter and side scatter properties and antigen expression of the leukemic and normal residual B-cells. We observed statistically significant differences in MFI levels of CD10, CD20, CD19, CD45, CD66 and Tdt of leukemic cells showing trends at different phases. Down modulation of CD10 was noticed from day 0-day 35 however up modulation was observed in subsequent phases. CD20 and TdT both showed significant and stable up modulation from day 0-day78. A steep down modulation was observed in CD45 and CD19 from day 0 to day 52 and thereafter remained stable. CD34 expression was variable and showed up modulation at day 35 followed by down modulation and then again a reincrease at day 78. CD66, CD33 and CD13 showed similar varying trends exhibiting up modulation at day 35 and then down modulation at day 52 and day 78. Residual normal B cells showed substantial decrease in antigenic expression for CD19, CD20 and CD45 till day 52 followed by an ascent at day 78. Conclusion: Immunophenotypic modulation occurred to different extents in all analyzed samples. Our results confirm the presence of transient immunophenotypic changes for CD10, CD34, CD13, CD33 and CD66 at induction phase of chemotherapy whereas CD20 and TdT showed irreversible gain in expression that is exploitable for MRD detection. The MFI of the different antigens expressed by the leukemic blasts should be taken into consideration and cautiously analyzed for MRD detection. Figure 1 Disclosures No relevant conflicts of interest to declare.

Comparison of Surface-Enhanced Raman Scattering Properties of Serum and Urine for the Detection of Chronic Kidney Disease in Patients.

Chronic kidney disease (CKD) affects more than 10% of the global population and is associated with significant morbidity and mortality. In most cases, this disease is developed silently, and it can progress to the end-stage renal failure. Therefore, early detection becomes critical for initiating effective interventions. Routine diagnosis of CKD requires both blood test and urinalyses in a clinical laboratory, which are time-consuming and have low sensitivity and specificity. Surface-enhanced Raman scattering (SERS) is an emerging method for rapidly assessing kidney function or injury. This study was designed to compare the differences between the SERS properties of the serum and urine for easy and simple detection of CKD. Enrolled for this study were 126 CKD patients (Stages 2–5) and 97 healthy individuals. SERS spectra of both the serum and urine samples were acquired using a Raman spectrometer (785 nm excitation). The correlation of chemical parameters of kidney function with the spectra was examined using prinicpal component analysis (PCA) combined with linear discriminant analysis (LDA) and partial least squares (PLS) analysis. Here, we showed that CKD was discriminated from non-CKD controls using PCA–LDA with a sensitivity of 74.6% and a specificity of 93.8% for the serum spectra, and 78.0% and 86.0 % for the urine spectra. The integration area under the receiver operating characteristic curve was 0.937 ± 0.015 (p < 0.0001) for the serum and 0.886 ± 0.025 (p < 0.0001) for the urine. The different stages of CKD were separated with the accuracy of 78.0% and 75.4% by the serum and urine spectra, respectively. PLS prediction (R2) of the serum spectra was 0.8540 for the serum urea (p < 0.001), 0.8536 for the serum creatinine (p < 0.001), 0.7500 for the estimated glomerular filtration rate (eGFR) (p < 0.001), whereas the prediction (R2) of urine spectra was 0.7335 for the urine urea (p < 0.001), 0.7901 for the urine creatinine (p < 0.001), 0.4644 for the eGFR (p < 0.001) and 0.6579 for the urine microalbumin (p < 0.001). In conclusion, the accuracy of associations between SERS findings of the serum and urine samples with clinical conclusions of CKD diagnosis in this limited number of patients is similar, suggesting that SERS may be used as a rapid and easy-to-use method for early screening of CKD, which however needs further evaluation in a large cohort study.

Non-Acute Myeloid Neoplasms With CD34(-) Blasts: Immunophenotypic And Clinical Analysis Of 5 Cases

Abstract Introduction/Objective Non-acute myeloid neoplasms (NAMNs) comprise clonal hematopoietic disorders, characterized by ≤20% myeloblasts in the peripheral blood (PB) and/or bone marrow (BM). The blasts of NAMN are almost exclusively CD34(+), contrasting with blasts in some acute myeloid leukemias (AML). We detail the clinicopathologic features of NAMN with CD34(-) blasts. Methods We searched 981 NAMN pathology reports for CD34(-) blasts by flow cytometry (FC). 8-color FC data was analyzed using cluster analysis to identify all relevant cell populations with a comprehensive antibody panel. CD34(-) blast populations were defined as reproducible clusters with similar light scatter properties across antibody tubes, after exclusion of other cell populations (e.g. basophils, neutrophils, mast cells). Blast aberrancies were defined as differences from established normal antigen expression patterns. PB and BM morphology was reviewed and chart reviews were performed. Results We identified 5 NAMN patients with CD34(-) blasts (2M, 3F; 57-84y/o) including 3 myelodysplastic syndrome (MDSs) with excess blasts, 1 therapy-related MDS, and 1 chronic myelomonocytic leukemia-1 (CMML). Blasts ranged from 0-1.5% in PB and 2.8-8% in BM. CD34(-) blasts accounted for 0.85-8.2% of BM events by FC, with all showing other aberrancies. The CMML patient had CD34(-) blasts with monocytic differentiation; all other CD34(-) blast populations showed expression of CD13, CD33, and CD117 and aberrant under-expression of CD38. Aberrancies were also present in the CD34(+) blasts in all patients (1-4/patient), accounting for 0.01-0.55% of events; 3/5 pts had under-expression of CD33, CD38, CD45, and/or HLA-DR. No cases had adverse cytogenetics. Patient outcomes included: indolent disease (1); died from disease 3 years post-diagnosis and chemotherapy (1); transformed to AML (2; 1-alive in complete remission; 1-died); and alive following allogeneic stem cell transplant (1). Conclusion Our data confirm that CD34(-) blasts are rarely observed in NAMN, and these patients have variable outcomes. Interestingly, all cases showed a concomitant aberrant CD34(+) blast population.

New views of tissue scattering

What causes scattering of ultrasound from normal soft tissues such as the liver, thyroid, and prostate? Commonly, the answer is formulated around the properties of spherical scatterers, related to cellular shapes and sizes. However an alternative view is that the closely packed cells forming the tissue parenchyma create the reference media, and the long cylindrical-shaped fluid vessels serve as the scattering sites. Under a weak scattering or Born approximation for the extracellular fluid in the vessels, and assuming an isotropic distribution of cylindrical channels across a wide range of diameters, consistent with a fractal branching pattern, some theoretical predictions can be made. Our model predicts that backscatter increases as a power law of frequency, where the power law is determined by the fractal dimension. These results are consistent with the pioneering measurements of Campbell and Waag. Furthermore, the normalized histogram of echo amplitudes is found to be related to the classical Burr distribution, with the key power law parameter directly related to the fractal dimension, expected in the range of 2 to 3 for normal vasculature. Thus, the first and second order statistics of backscatter from soft vascularized tissues appear to be determined by fractal branching cylindrical vessels.

Low-Dose IL-2 for Treating Moderate to Severe Alopecia Areata: A 52-Week Multicenter Prospective Placebo-Controlled Study Assessing its Impact on T Regulatory Cell and NK Cell Populations

Low-Dose IL-2 for Treating Moderate to Severe Alopecia Areata: A 52-Week Multicenter Prospective Placebo-Controlled Study Assessing its Impact on T Regulatory Cell and NK Cell Populations

Quantifying scattering from dense media using two-dimensional impedance maps.

A better understanding of ultrasound scattering in a three-dimensional (3D) medium can provide more accurate methods for ultrasound tissue characterization. The possibility of using two-dimensional impedance maps (2DZMs) based on correlation coefficients has shown promise in the case of isotropic and sparse medium [Luchies and Oelze, J. Acoust. Soc. Am. 139, 1557-1564 (2016)]. The present study investigates the use of 2DZMs in order to quantify 3D scatterer properties of dense media from two-dimensional (2D) histological slices. Two 2DZM approaches were studied: one based on the correlation coefficient and the other based on the 2D Fourier transform of 2DZMs. Both 2DZM approaches consist in estimating the backscatter coefficient (BSC) from several 2DZMs, and then the resulting BSC was fit to the theoretical polydisperse structure factor model to yield 3D scatterer properties. Simulation studies were performed to evaluate the ability of both 2DZM approaches to quantify scattering of a 3D medium containing randomly distributed polydisperse spheres or monodisperse ellipsoids. Experimental studies were also performed using the histology photomicrographs obtained from HT29 cell pellet phantoms. Results demonstrate that the 2DZM Fourier transform-based approach was more suitable than the correlation coefficient-based approach for estimating scatterer properties when using a small number of 2DZMs.