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Wolf phase tomography(WPT) of transparent structures using partially coherent illumination

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Light(Science & Applications) 2020年第1期9卷 656-664页

作者： Xi Chen Mikhail E.Kandel Chenfei Hu Young Jae Lee gabriel.popescu Quantitative Light Imaging Laboratory Beckman Institute for Advanced Science and TechnologyDepartment of Electrical and Computer EngineeringUniversity of Illinois at Urbana-ChampaignUrbanaIL 61801USA

In 1969,Emil Wolf proposed diffraction tomography using coherent holographic imaging to extract 3D information from transparent,inhomogeneous *** the same era,the Wolf equations were first used to describe the propagation correlations associated with partially coherent *** these two concepts,we present Wolf phase tomography(WPT),which is a method for performing diffraction tomography using partially coherent *** reconstruction works directly in the space-time domain,without the need for Fourier transformation,and decouples the refractive index(RI)distribution from the thickness of the *** demonstrate the WPT principle using the data acquired by a quantitative-phase-imaging method that upgrades an existing phase-contrast microscope by introducing controlled phase shifts between the incident and scattered *** illumination field in WPT is partially spatially coherent(emerging from a ring-shaped pupil function)and of low temporal coherence(white light),and as such,it is well suited for the Wolf *** three intensity measurements corresponding to different phase-contrast frames,the 3D RI distribution is obtained immediately by computing the Laplacian and second time derivative of the measured complex correlation *** validate WPT with measurements of standard samples(microbeads),spermatozoa,and live neural *** high throughput and simplicity of this method enables the study of 3D,dynamic events in living cells across the entire multiwell plate,with an RI sensitivity on the order of 10^(−5).

关键词： WPT coherent illumination

Endoscopic ultrasound-guided fine-needle aspiration pancreatic adenocarcinoma samples yield adequate DNA for next-generation sequencing:A cohort analysis

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World Journal of Gastroenterology 2023年第18期29卷 2864-2874页

作者： Stefania Bunduc Bianca Varzaru Razvan Andrei Iacob Andrei Sorop Ioana Manea Andreea Spiridon Raluca Chelaru Adina Emilia Croitoru gabriel Becheanu Mona Dumbrava Simona Dima Irinel popescu Cristian Gheorghe Faculty of Medicine Carol Davila University of Medicine and PharmacyBucharest 020021Romania Digestive Diseases and Liver Transplantation Center Fundeni Clinical InstituteBucharest 022328Romania Center of Excellence in Translational Medicine Fundeni Clinical InstituteBucharest 022328Romania

BACKGROUND Genetic tests are increasingly performed for the management of unresectable pancreatic *** genotyping aimed samples current guidelines recommend using core specimens,although based on moderate quality ***,in clinical practice among the endoscopic ultrasound(EUS) guided tissue acquisition methods,fine needle aspiration(FNA) is the most widely *** To assess the adequacy for next generation sequencing(NGS) of the DNA yielded from EUS-FNA pancreatic adenocarcinoma(PDAC) *** Between November 2018 and December 2021,105 patients with PDAC confirmed by EUS-FNA were included in the study at our tertiary gastroenterology *** 22 gauge(G) or 19G FNA needles were *** pass was dedicated to DNA *** concentration and purity(A260/280,A260/230) were assessed by *** assessed the differences in DNA parameters according to needle size and tumor characteristics(size,location) and the adequacy of the extracted DNA for NGS(defined as A260/280 ≥ 1.7,and DNA yield:≥ 10 ng for amplicon based NGS,≥ 50 ng for whole exome sequencing [WES],≥ 100 ng for whole genome sequencing [WGS]) by analysis of variance and ttest ***,we compared DNA purity parameters across the different DNA yield *** Our cohort included 49% male patients,aged 67.02 ± 8.38 *** 22G needle was used in 71%of the *** DNA parameters across our samples varied as follows:DNA yield:1289 ng(inter quartile range:534.75-3101),A260/280 = 1.85(1.79-1.86),A260/230 = 2.2(1.72-2.36).DNA yield was > 10 ng in all samples and > 100 ng in 93% of them(one sample < 50 ng).There were no significant differences in the concentration and A260/280 between samples by needle *** size was the only independent predictor of A260/230 which was higher in the 22G samples(P =0.038).NGS adequacy rate was 90% for 19G samples regardless of NGS type,and for 22G samples it reached 89% for WGS adequacy and 91% for WES and

关键词： Pancreatic adenocarcinoma Endoscopic ultrasound guided fine needle aspiration Next generation sequencing DNA yield Needle size Genetic testing

Gabor’s holography at sea

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Light(Science & Applications) 2019年第1期8卷 1004-1005页

作者： gabriel.popescu Quantitative Light Imaging Laboratory Department of Electrical and Computer EngineeringBeckman Institute for Advanced Science and TechnologyUniversity of Illinois at Urbana-ChampaignUrbanaIL 61801USA

In 1948,predating lasers by more than a decade,Gabor proposed a“new microscopic principle”,which was initially aimed at correcting spherical aberrations in electron *** the method has not produced an impact in its originally intended field,it opened a new direction,known as holography,in ***’s technique allows one to store phase information by recording on film the intensity of a field emerging at a certain distance from an object.

关键词： Gabor recording initially

Large-scale phase retrieval

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Light(Science & Applications) 2021年第10期10卷 1814-1815页

The coherent interaction between an electromagnetic field and a 3D weakly scattering medium results in a simple Fourier transform relationship between the object’s structure and the complex scattered *** a result,knowledge about the phase of the scattered field is necessary for solving this inverse problem with a unique ***,in applications,such as X-ray crystallography,typically one only has experimental access to the amplitude of the diffracted field,which results in ambiguities of the *** century-old challenge,known as“the phase problem”2 motivated the development of computational algorithms combined with a priori knowledge about the object of interest to limit the solution *** generally successful,this approach sometimes led to multiple solutions,i.e.,different inferred object structures for the same set of data:“Not all the guesses have been *** is clear,for example,from the following:Two different structures were predicted for the mineral bixbyite,one by ***,the other by *** is not known which,if either,is correct.”(Chapter 7 in ref.2).

关键词： phase scattered typically

High-resolution impedance mapping using electrically activated quantitative phase imaging

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Light(Science & Applications) 2021年第2期10卷 186-196页

作者： Cristina Polonschii Mihaela Gheorghiu Sorin David Szilveszter Gáspár Sorin Melinte Hassaan Majeed Mikhail E.Kandel gabriel.popescu Eugen Gheorghiu International Centre of Biodynamics 060101 BucharestRomania Institute of Information and Communication Technologies Electronics and Applied MathematicsUniversite Catholique de Louvain1348 Louvain-la-NeuveBelgium Quantitative Light Imaging Laboratory Beckman Institute for Advanced Science and TechnologyUniversity of Illinois at Urbana-ChampaignUrbanaIL 61801USA

Retrieving electrical impedance maps at the nanoscale rapidly via nondestructive inspection with a high signal-to-noise ratio is an unmet need,likely to impact various applications from biomedicine to energy *** this study,we develop a multimodal functional imaging instrument that is characterized by the dual capability of impedance mapping and phase quantitation,high spatial resolution,and low temporal *** achieve this,we advance a quantitative phase imaging system,referred to as epi-magnified image spatial spectrum microscopy combined with electrical actuation,to provide complementary maps of the optical path and electrical *** demonstrate our system with high-resolution maps of optical path differences and electrical impedance variations that can distinguish nanosized,semi-transparent,structured coatings involving two materials with relatively similar electrical *** map heterogeneous interfaces corresponding to an indium tin oxide layer exposed by holes with diameters as small as~550 nm in a titanium(dioxide)over-layer deposited on a glass *** show that electrical modulation during the phase imaging of a macro-electrode is decisive for retrieving electrical impedance distributions with submicron spatial resolution-and beyond the limitations of electrode-based technologies(surface or scanning technologies).The findings,which are substantiated by a theoretical model that fits the experimental data very well enable achieving electro-optical maps with high spatial and temporal *** virtues and limitations of the novel optoelectrochemical method that provides grounds for a wider range of electrically modulated optical methods for measuring the electric field locally are critically discussed.

关键词： impedance resolution phase

Real-time sono-elastography in the diagnosis of diffuse liver diseases

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World Journal of Gastroenterology 2010年第14期16卷 1720-1726页

作者： Dan Ionut Gheonea Adrian S ǎftoiu Tudorel Ciurea Florin Gorunescu Sevastita Iordache gabriel Lucian popescu Smaranda Belciug Marina Gorunescu Larisa Sǎndulescu Research Center of Gastroenterology and Hepatology University of Medicine and Pharmacy Craiova 200349 Romania Department of Biostatistics and Informatics University of Medicine and Pharmacy Craiova 200349 Romania IT Department University of Medicine and Pharmacy Craiova 200349 Romania Faculty of Mathematics of Computer Science University of Craiova Craiova 200585 Romania

AIM: To analyze whether computer-enhanced dynamic analysis of elastography movies is able to better characterize and differentiate between different degrees of liver fibrosis. METHODS: The study design was prospective. A total of 132 consecutive patients with chronic liver diseases and healthy volunteers were examined by transabdominal ultrasound elastography. All examinations were done by two ***: Due to the limitations of the method, we obtained high-quality elastography information in only 73.48% of the patients. The κ-means clustering method was applied to assess the inter-observer diagnosis varia- bility, which showed good variability values in accordance with the experience of ultrasound examination of every observer. Cohen’sκ test indicated a moderate agreement between the study observers (κ = 0.4728). Furthermore, we compared the way the two observers clustered the patients, using the test for comparing two proportions (t value, two-sided test). There was no statistically significant difference between the two physicians, regardless of the patients’ real status. CONCLUSION: Transabdominal real-time elastography is certainly a very useful method in depicting liver hard- ness, although it is incompletely tested in large multicenter studies.

关键词： Elastography Ultrasonography Liver steato- sis Viral hepatitis Liver cirrhosis

Optically monitoring and controlling nanoscale topography during semiconductor etching

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Light(Science & Applications) 2012年第1期1卷 41-46页

作者： Chris Edwards Amir Arbabi gabriel.popescu Lynford L Goddard Department of Electrical and Computer Engineering University of Illinois at Urbana-ChampaignUrbanaIL 61801USA

We present epi-diffraction phase microscopy(epi-DPM)as a non-destructive optical method for monitoring semiconductor fabrication processes in real time and with nanometer level *** method uses a compact Mach–Zehnder interferometer to recover quantitative amplitude and phase maps of the field reflected by the *** low temporal noise of 0.6 nm per pixel at 8.93 frames per second enabled us to collect a three-dimensional movie showing the dynamics of wet etching and thereby accurately quantify non-uniformities in the etch rate both across the sample and over *** displaying a gray-scale digital image on the sample with a computer projector,we performed photochemical etching to define arrays of microlenses while simultaneously monitoring their etch profiles with epi-DPM.

关键词： microscopy nanoscale metrology photochemical etching quantitative phase imaging semiconductor process monitoring

Bond-selective transient phase imaging via sensing of the infrared photothermal effect

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Light(Science & Applications) 2019年第1期8卷 70-81页

作者： Delong Zhang Lu Lan Yeran Bai Hassaan Majeed Mikhail E.Kandel gabriel.popescu Ji-Xin Cheng Department of Biomedical Engineering Boston UniversityBostonMA 02215USA Department of Physics Zhejiang UniversityHangzhou 310028China National Laboratory on High Power Laser and Physics Shanghai 201800China Key Laboratory of High Power Laser and Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Department of Bioengineering University of Illinois at Urbana-ChampaignChampaignIL 61801USA Department of Electrical and Computer Engineering University of Illinois at Urbana-ChampaignChampaignIL 61801USA Department of Electrical&Computer Engineering Boston UniversityBostonMA 02215USA Photonics Center Boston UniversityBostonMA 02215USA

Phase-contrast microscopy converts the phase shift of light passing through a transparent specimen,e.g.,a biological cell,into brightness variations in an *** ability to observe structures without destructive fixation or staining has been widely utilized for applications in materials and life *** these advantages,phase-contrast microscopy lacks the ability to reveal molecular *** address this gap,we developed a bond-selective transient phase(BSTP)imaging technique that excites molecular vibrations by infrared light,resulting in a transient change in phase shift that can be detected by a diffraction phase *** developing a time-gated pump-probe camera system,we demonstrate BSTP imaging of live cells at a 50 Hz frame rate with high spectral fidelity,sub-microsecond temporal resolution,and sub-micron spatial *** approach paves a new way for spectroscopic imaging investigation in biology and materials science.

关键词： transient phase utilized

Label-free SARS-CoV-2 detection and classification using phase imaging with computational specificity

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Light(Science & Applications) 2021年第9期10卷 1797-1808页

作者： Neha Goswami Yuchen R.He Yu-Heng Deng Chamteut Oh Nahil Sobh Enrique Valera Rashid Bashir Nahed Ismail Hyunjoon Kong Thanh H.Nguyen Catherine Best-popescu gabriel.popescu Department of Bioengineering University of Illinois Urbana-ChampaignUrbanaIllinois61801USA Beckman Institute of Advanced Science and Technology University of Illinois Urbana-ChampaignUrbanaIllinois61801USA Department of Electrical and Computer Engineering University of Illinois Urbana-ChampaignUrbanaIllinois61801USA Department of Chemical and Biomolecular Engineering University of Illinois at Urbana-ChampaignUrbanaIL61801USA Department of Civil and Environmental Engineering University of Illinois at Urbana-ChampaignUrbanaIL61801USA NCSA Center for Artificial Intelligence Innovation University of Illinois at Urbana-ChampaignUrbanaIL61801USA Holonyak Micro and Nanotechnology Laboratory University of Illinois at Urbana-ChampaignUrbanaIllinois61801USA Biomedical Research Center Carle Foundation Hospital509W University Ave.UrbanaIllinois61801USA Carle Illinois College of Medicine 807 South Wright St.UrbanaIllinois61801USA Mayo-Illinois Alliance for Technology Based Healthcare UrbanaIllinois61801USA Department of Pathology College of MedicineUniversity of Illinois at ChicagoChicagoILUSA

Efforts to mitigate the COVID-19 crisis revealed that fast,accurate,and scalable testing is crucial for curbing the current impact and that of future *** propose an optical method for directly imaging unlabeled viral particles and using deep learning for detection and *** ultrasensitive interferometric method was used to image four virus types with nanoscale optical path-length *** these data with fluorescence images for ground truth,we trained semantic segmentation models based on U-Net,a particular type of convolutional neural *** trained network was applied to classify the viruses from the interferometric images only,containing simultaneously SARS-CoV-2,H1N1(influenza-A virus),HAdV(adenovirus),and ZIKV(Zika virus).Remarkably,due to the nanoscale sensitivity in the input data,the neural network was able to identify SARS-CoV-2 *** other viruses with 96%*** inference time for each image is 60 ms,on a common graphic-processing *** approach of directly imaging unlabeled viral particles may provide an extremely fast test,of less than a minute per *** the imaging instrument operates on regular glass slides,we envision this method as potentially testing on patient breath *** necessary high throughput can be achieved by translating concepts from digital pathology,where a microscope can scan hundreds of slides automatically.

关键词： testing neural hundreds