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Recent Advancements in Optical Harmonic Generation Microscopy: Applications and Perspectives

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Biomedical Engineering Frontiers 2021年第1期2卷 65-88页

作者： Darian S.james Paul j.Campagnola Department of Biomedical Engineering University of Wisconsin-Madison1550 Engineering DrMadisonWI 53706USA

Second harmonic generation(SHG)and third harmonic generation(THG)microscopies have emerged as powerful imaging modalities to examine structural properties of a wide range of biological *** SHG and THG arise from very different contrast mechanisms,the two are complimentary and can often be collected simultaneously using a modified multiphoton *** this review,we discuss the needed instrumentation for these modalities as well as the underlying theoretical principles of SHG and THG in tissue and describe how these can be leveraged to extract unique structural *** provide an overview of recent advances showing how SHG microscopy has been used to evaluate collagen alterations in the extracellular matrix and how this has been used to advance our knowledge of cancers,fibroses,and the cornea,as well as in tissue engineering *** examples using polarization-resolved approaches and machine learning algorithms are ***,we review how THG has enabled developmental biology and skin cancer studies due to its sensitivity to changes in refractive index,which are ubiquitous in all cell and tissue ***,we offer perspectives and outlooks on future directions of SHG and THG microscopies and present unresolved questions,especially in terms of overall miniaturization and the development of microendoscopy instrumentation.

关键词： harmonic resolved directions

Estimating geographic variation of infection fatality ratios during epidemics

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Infectious Disease Modelling 2024年第2期9卷 634-643页

作者： joshua Ladau Eoin L.Brodie Nicola Falco Ishan Bansal Elijah B.Hoffman Marcin P.joachimiak Ana M.Mora Angelica M.Walker Haruko M.Wainwright Yulun Wu Mirko Pavicic Daniel jacobson Matthias Hess james B.Brown Katrina Abuabara Departments of Computational Precision Health and Dermatology University of CaliforniaSan FranciscoCA94115USA Arva Intelligence Inc.Salt Lake CityUT84101USA Computational Biosciences Group Lawrence Berkeley National LaboratoryBerkeleyCA94720USA Earth and Environmental Sciences Area Lawrence Berkeley National LaboratoryBerkeleyCA94720USA Graduate Group in Biostatistics University of CaliforniaBerkeleyCA94720USA Biosystems Data Science Environmental Genomics and Systems BiologyLawrence Berkeley National LaboratoryBerkeleyCA94720USA Center for Environmental Research and Community Health(CERCH) School of Public HealthUniversity of CaliforniaBerkeleyCA94720USA Bredesen Center for Interdisciplinary Research and Graduate Education University of TennesseeKnoxvilleTN37996USA Department of Nuclear Science and Engineering Massachusetts Institute of TechnologyBostonMA02139USA Biosciences Oak Ridge National LaboratoryOak RidgeTN37830USA University of California DavisCA95616USA Statistics Department University of CaliforniaBerkeleyCA94720USA Division of Epidemiology and Biostatistics University of California Berkeley School of Public Health2121 Berkeley WayBerkeleyCA94720USA

Objectives We aim to estimate geographic variability in total numbers of infections and infection fatality ratios(IFR;the number of deaths caused by an infection per 1,000 infected people)when the availability and quality of data on disease burden are limited during an *** We develop a noncentral hypergeometric framework that accounts for differential probabilities of positive tests and reflects the fact that symptomatic people are more likely to seek *** demonstrate the robustness,accuracy,and precision of this framework,and apply it to the United States(U.S.)COVID-19 pandemic to estimate county-level SARS-CoV-2 *** The estimators for the numbers of infections and IFRs showed high accuracy and precision;for instance,when applied to simulated validation data sets,across counties,Pearson correlation coefficients between estimator means and true values were 0.996 and 0.928,respectively,and they showed strong robustness to model *** the county-level estimators to the real,unsimulated COVID-19 data spanning April 1,2020 to September 30,2020 from across the U.S.,we found that IFRs varied from 0 to 44.69,with a standard deviation of 3.55 and a median of *** The proposed estimation framework can be used to identify geographic variation in IFRs across settings.

关键词： Infection fatality ratio Infection fatality rate Noncentral hypergeometric distribution COVID-19 SARS-CoV-2

A Pressure Relaxation Closure Model for One-Dimensional, Two-Material Lagrangian Hydrodynamics Based on the Riemann Problem

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Communications in Computational Physics 2010年第5期7卷 927-976页

作者： james R.Kamm Mikhail j.Shashkov Applied Physics Division Los Alamos National LaboratoryLos AlamosNM 87545USA Theoretical Division Los Alamos National LaboratoryLos AlamosNM 87545USA

Despite decades of development, Lagrangian hydrodynamics of strengthfree materials presents numerous open issues, even in one dimension. We focus on theproblem of closing a system of equations for a two-material cell under the assumptionof a single velocity model. There are several existing models and approaches, eachpossessing different levels of fidelity to the underlying physics and each exhibitingunique features in the computed solutions. We consider the case in which the changein heat in the constituent materials in the mixed cell is assumed equal. An instantaneous pressure equilibration model for a mixed cell can be cast as four equations infour unknowns, comprised of the updated values of the specific internal energy andthe specific volume for each of the two materials in the mixed cell. The unique contribution of our approach is a physics-inspired, geometry-based model in which theupdated values of the sub-cell, relaxing-toward-equilibrium constituent pressures arerelated to a local Riemann problem through an optimization principle. This approachcouples the modeling problem of assigning sub-cell pressures to the physics associated with the local, dynamic evolution. We package our approach in the frameworkof a standard predictor-corrector time integration scheme. We evaluate our model using idealized, two material problems using either ideal-gas or stiffened-gas equationsof state and compare these results to those computed with the method of Tipton andwith corresponding pure-material calculations.

关键词： Lagrangian hydrodynamics compressible flow multi-material flow pressure relaxation

Recent Increased Warming of the Alaskan Marine Arctic Due to Midlatitude Linkages

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Advances in Atmospheric Sciences 2018年第1期35卷 75-84页

作者： james E.OVERLAND Muyin WANG Thomas j.BALLINGER NOAA/Pacific Marine Environmental Laboratory Seattle WA 98115USA joint Institute for the Study of Atmosphere and Oceans University of Washington Seattle WA 98115USA Department of Geography Texas State UniversitySan Marcos TX 78666USA

Alaskan Arctic waters have participated in hemispheric-wide Arctic warming over the last two decades at over two times the rate of global warming. During 2008–13, this relative warming occurred only north of the Bering Strait and the atmospheric Arctic front that forms a north–south thermal barrier. This front separates the southeastern Bering Sea temperatures from Arctic air masses. Model projections show that future temperatures in the Chukchi and Beaufort seas continue to warm at a rate greater than the global rate, reaching a change of +4℃ by 2040 relative to the 1981–2010 mean. Offshore at 74°N, climate models project the open water duration season to increase from a current average of three months to five months by 2040. These rates are occasionally enhanced by midlatitude connections. Beginning in August 2014, additional Arctic warming was initiated due to increased SST anomalies in the North Pacific and associated shifts to southerly winds over Alaska, especially in winter 2015–16. While global warming and equatorial teleconnections are implicated in North Pacific SSTs, the ending of the 2014–16 North Pacific warm event demonstrates the importance of internal, chaotic atmospheric natural variability on weather conditions in any given year. Impacts from global warming on Alaskan Arctic temperature increases and sea-ice and snow loss, with occasional North Pacific support, are projected to continue to propagate through the marine ecosystem in the foreseeable future. The ecological and societal consequences of such changes show a radical departure from the current Arctic environment.

关键词： Alaska North Pacific Arctic warm advection polar vortex

Placement of removable metal biliary stent in post-orthotopic liver transplantation anastomotic stricture

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World journal of Gastroenterology 2010年第28期16卷 3597-3600页

作者： Hoi-Poh Tee Martin W james Arthur j Kaffes Gastroenterology Unit Medical Department Hospital Tengku Ampuan AfzanJalan Tanah Putih25100 KuantanPahangMalaysia Wolfson Digestive Disease Biomedical Re search Unit Nottingham NG7 2UHUnited Kingdom AW Morrow Gastroenterology and Live Centre Royal Prince Alfred HospitalMissenden RoadCamp erdownNSW 2050Australia

Postoperative biliary strictures are the most common cause of benign biliary stricture in Western countries, secondary to either operative injury or bile duct anastomotic stricture following orthotopic liver transplantation(OLT).Surgery or endoscopic interventions are the mainstay of treatment for benign biliary *** aim to report the outcome of 2 patients with refractory anastomotic biliary stricture post-OLT,who had successful temporary placement of a prototype removable covered self-expandable metal stent(RCSEMS).These 2 patients(both men,aged 44 and 53 years)were given temporary placement of a prototype RCSEMS (8.5 Fr gauge delivery system,8 mm×40 mm stent dimensions)in the common bile duct across the biliary *** was no morbidity associated with stent placement and removal in these 2 *** parameters improved after the RCSEMS *** biliary patency was achieved in both the patients. No further biliary intervention was required within 14 and 18 mo follow-up after stent removal.

关键词： Anastomosis Biliary stent Biliary stricture Orthotopic liver transplantation Niti-S stent

A polarizing situation： Taking an in-plane perspective for next-generation near-field studies

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Frontiers of physics 2016年第2期11卷 1-17页

作者： P. james Schuck Wel Bao Nicholas j. Borys Molecular Foundry Lawrence Berkeley National Laboratory Berkeley CA 94720 USA Department of Materials Science and Engineering University of California Berkeley CA 94720-1760 USA

By enabling the probing of light-matter interactions at the functionally relevant length scales of most materials, near-field optical imaging and spectroscopy accesses information that is unobtainable with other methods. The advent of apertureless techniques, which exploit the ultralocalized and enhanced near-fields created by sharp metallic tips or plasmonic nanoparticles, has resulted in rapid adoption of near-field approaches for studying novel materials and phenomena, with spatial resolution approaching sub-molecular levels. However, these approaches are generally limited by the dominant out-of-plane polarization response of apertureless tips, restricting the exploration and discovery of many material properties. This has led to recent design and fabrication breakthroughs in near-field tips engineered specifically for enhancing in-plane interactions with near-field light components. This mini-review provides a perspective on recent progress and emerging directions aimed at utilizing and controlling in-plane optical polarization, highlighting key application spaces where in-plane near-field tip responses have enabled recent advancements in the understanding and development of new nanostructured materials and devices.

关键词： near-field optical microscopy nano-optics TERS plasmonics optical antenna 2D materials

Statistical distribution of geomechanical properties and‘Sweet Spots’identification in part of the upper Bakken

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Petroleum Research 2023年第3期8卷 301-308页

作者： Nelson R.K.Tatsipie james j.Sheng Texas Tech University United States

Completions and Reservoir Quality are two key attributes that are used to characterize nonconventional hydrocarbon *** is because,for optimum exploitation of these unconventional assets,horizontal wells need to be drilled in“Sweet Spots”(i.e.,regions where Completions and Reservoir Quality are both superior).One way to quantify these qualities is to use reservoir and geomechanical *** properties can be estimated on a location basis from well logs,and then mapped over terrain using geostatistical *** study presents a‘Sweet Spots’identification workflow based on three performance indexes(Storage Potential Index,Brittleness Index,and Horizontal Stress Index)that can be used to quantify CQ and *** performance indexes are computed from petrophysical property volumes(of Young's Modulus,Bulk Modulus,Shear Modulus,Poisson's Ratio,Minimum Horizontal Stress,Volume of Shale,Total Organic Carbon,Thickness,and Porosity)which are in turn computed from well logs and geostatistical *** the end,the study offers a method to compare the predicted“Sweet Spots”against available production data via their correlation *** resulting reasonable formation property maps,the successful identification of‘Sweet Spots’,and a correlation coefficient of 0.88(between the predicted“Sweet Spots”and well production data)point to the potential of the proposed effort.

关键词： Sweet spots Sequential Gaussian simulation Storage potential index Brittleness index Horizontal stress index

Semi-transparent,flexible,and electrically conductive silicon mesh by capillarity-driven welding of vapor-liquid-solid-grown nanowires over large areas

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Nano Research 2020年第5期13卷 1465-1471页

作者： Thomas A.Celano Seokhyoung Kim David j.Hill james F.Cahoon Department of Chemistry University of North Carolina at Chapel HillChapel HillNC 27599-3290USA

Bottom-up synthesis of semiconductor nanowires(NWs)by the vapor-liquid-solid(VLS)mechanism has enabled diverse technological applications for these *** metallic NWs,however,it has been challenging to form large-area interconnected NW ***,we generate centimeter-scale meshes of mechanically and electrically interconnected Si NWs by sequentially growing,collapsing,and joining the NWs using a capillarity-driven welding *** fabricate meshes from VLS-grown NWs ranging in diameter from 20 to 100 nm and find that the meshes are three-dimensional with a thickness ranging from^1 to^10 microns depending on the NW *** extinction measurements reveal that the networks are semi-transparent with a color that depends on the absorption and scattering characteristics of individual ***,active voltage contrast imaging of both centimeter-and micron-scale meshes reveals widespread electrical *** a sacrificial layer,we demonstrate that the mesh can be liberated from the growth substrate,yielding a highly flexible and transparent *** transport measurements both on the growth substrate and on liberated,flexible films reveal electrical conduction across a centimeter scale with a sheet resistance of^160-180 kΩ/square that does not change significantly upon *** the ability to encode complex functionality in semiconductor NWs through the VLS process,we believe these meshes of networked NWs could find application as neuromorphic memory,electrode scaffolds,and bioelectronic interfaces.

关键词： semiconductor nanowire conductive network flexible electronics welding thermal annealing active-voltage contrast

Progressive heterosis in genetically defined tetraploid maize

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journal of Genetics and Genomics 2019年第8期46卷 389-396页

作者： jacob D.Washburn Mitchell j.McElfresh james A.Birchler Division of Biological Sciences University of Missouri

Progressive heterosis, i.e., the additional hybrid vigor in double-cross tetraploid hybrids not found in their single-cross tetraploid parents, has been documented in a number of species including alfalfa,potato, and maize. In this study, four artificially induced maize tetraploids, directly derived from standard inbred lines, were crossed in pairs to create two single-cross hybrids. These hybrids were then crossed to create double-cross hybrids containing genetic material from all four original lines. Replicated fieldbased phenotyping of the materials over four years indicated a strong progressive heterosis phenotype in tetraploids but not in their diploid counterparts. In particular, the above ground dry weight phenotype of double-cross tetraploid hybrids was on average 34% and 56% heavier than that of the single-cross tetraploid hybrids and the double-cross diploid counterparts, respectively. Additionally,whole-genome resequencing of the original inbred lines and further analysis of these data did not show the expected spectrum of alleles to explain tetraploid progressive heterosis under the complementation of complete recessive model. These results underscore the reality of the progressive heterosis phenotype,its potential utility for increasing crop biomass production, and the need for exploring alternative hypothesis to explain it at a molecular level.

关键词： Maize Tetraploid Heterosis Dominance complementation Progressive heterosis