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| 1 | Real-time sono-elastography in the diagnosis of diffuse liver diseases显示文摘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 doctors.RESULTS: 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. | Dan Ionut Gheonea Adrian S ǎftoiu Tudorel Ciurea Florin Gorunescu Sevastita Iordache Gabriel Lucian Popescu Smaranda Belciug Marina Gorunescu Larisa Sǎndulescu | 2010 | World Journal of Gastroenterology2010，16，14： | 9 |
| 2 | Wolf phase tomography(WPT) of transparent structures using partially coherent illumination显示文摘In 1969,Emil Wolf proposed diffraction tomography using coherent holographic imaging to extract 3D information from transparent,inhomogeneous objects.In the same era,the Wolf equations were first used to describe the propagation correlations associated with partially coherent fields.Combining these two concepts,we present Wolf phase tomography(WPT),which is a method for performing diffraction tomography using partially coherent fields.WPT 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 sample.We 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 fields.The 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 equations.From 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 function.We validate WPT with measurements of standard samples(microbeads),spermatozoa,and live neural cultures.The 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). | Xi Chen Mikhail E.Kandel Chenfei Hu Young Jae Lee Gabriel Popescu | 2020 | Light(Science & Applications)2020，9，1： | 6 |
| 3 | Optically monitoring and controlling nanoscale topography during semiconductor etching显示文摘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 sensitivity.The method uses a compact Mach–Zehnder interferometer to recover quantitative amplitude and phase maps of the field reflected by the sample.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 time.By 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. | Chris Edwards Amir Arbabi Gabriel Popescu Lynford L Goddard | 2012 | Light(Science & Applications)2012，1，1： | 5 |
| 4 | Label-free SARS-CoV-2 detection and classification using phase imaging with computational specificity显示文摘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 pandemics.We propose an optical method for directly imaging unlabeled viral particles and using deep learning for detection and classification.An ultrasensitive interferometric method was used to image four virus types with nanoscale optical path-length sensitivity.Pairing these data with fluorescence images for ground truth,we trained semantic segmentation models based on U-Net,a particular type of convolutional neural network.The 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 vs.the other viruses with 96%accuracy.The inference time for each image is 60 ms,on a common graphic-processing unit.This approach of directly imaging unlabeled viral particles may provide an extremely fast test,of less than a minute per patient.As the imaging instrument operates on regular glass slides,we envision this method as potentially testing on patient breath condensates.The necessary high throughput can be achieved by translating concepts from digital pathology,where a microscope can scan hundreds of slides automatically. | 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 | 2021 | Light(Science & Applications)2021，10，9： | 3 |
| 5 | Bond-selective transient phase imaging via sensing of the infrared photothermal effect显示文摘Phase-contrast microscopy converts the phase shift of light passing through a transparent specimen,e.g.,a biological cell,into brightness variations in an image.This ability to observe structures without destructive fixation or staining has been widely utilized for applications in materials and life sciences.Despite these advantages,phase-contrast microscopy lacks the ability to reveal molecular information.To 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 microscope.By 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 resolution.Our approach paves a new way for spectroscopic imaging investigation in biology and materials science. | Delong Zhang Lu Lan Yeran Bai Hassaan Majeed Mikhail E.Kandel Gabriel Popescu Ji-Xin Cheng | 2019 | Light(Science & Applications)2019，8，1： | 3 |
| 6 | Neural Network Analysis of Dynamic Sequences of EUS Elastography Used for the Differential Diagnosis of Chronic Pancreatitis and Pancreatic Cancer显示文摘 | Adrian Saftoiu Peter Vilmann Florin Gorunescu Dan Ionut Gheonea Marina Gorunescu Tudorel Ciurea Gabriel Lucian Popescu Alexandru Iordache Sevastita Iordache | 2008 | Gastrointestinal Endoscopy2008，，5： | 2 |
| 7 | High-resolution impedance mapping using electrically activated quantitative phase imaging显示文摘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 conversion.In 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 noise.To 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 impedance.We 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 properties.We 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 support.We 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 resolutions.The 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. | Cristina Polonschii Mihaela Gheorghiu Sorin David Szilveszter Gáspár Sorin Melinte Hassaan Majeed Mikhail E.Kandel Gabriel Popescu Eugen Gheorghiu | 2021 | Light(Science & Applications)2021，10，2： | 2 |
| 8 | Combined contrast-enhanced power Doppler and real-time sonoelastography performed during EUS, used in the differential diagnosis of focal pancreatic masses (with videos)显示文摘 | Adrian S?ftoiu Sevasti?a Iordache Dan Ionu? Gheonea Carmen Popescu Anca Malo? Florin Gorunescu Tudorel Ciurea Alexandru Iordache Gabriel Lucian Popescu Cǎtǎlin Manea | 2010 | Gastrointestinal Endoscopy2010，，4： | 2 |
| 9 | Combined contrast-enhanced power Doppler and real-time sonoelastography performed during EUS, used in the differential diagnosis of focal pancreatic masses (with videos)显示文摘 | Adrian S?ftoiu Sevasti?a Iordache Dan Ionu? Gheonea Carmen Popescu Anca Malo? Florin Gorunescu Tudorel Ciurea Alexandru Iordache Gabriel Lucian Popescu Cǎtǎlin Manea | 2010 | Gastrointestinal Endoscopy2010，，4： | 1 |
| 10 | Neural network analysis of dynamic sequences of EUS elastography used for the differential diagnosis of chronic pancreatitis and pancreatic cancer显示文摘 | Adrian S?ftoiu Peter Vilmann Florin Gorunescu Dan Ionu? Gheonea Marina Gorunescu Tudorel Ciurea Gabriel Lucian Popescu Alexandru Iordache Hazem Hassan Sevasti?a Iordache | 2008 | Gastrointestinal Endoscopy2008，，6： | 1 |
| 11 | Nanocrystalline Er:YAG thin films prepared by pulsed laser deposition: An electron microscopy study显示文摘 | Daniela Stanoi Andrei Popescu Corneliu Ghica Gabriel Socol Emanuel Axente Carmen Ristoscu Ion N. Mihailescu Andrea Stefan Serban Georgescu | 2007 | Applied Surface Science2007，，19： | 1 |
| 12 | GANscan:continuous scanning microscopy using deep learning deblurring显示文摘Most whole slide imaging(WSI)systems today rely on the'stop-and-stare'approach,where,at each field of view,the scanning stage is brought to a complete stop before the camera snaps a picture.This procedure ensures that each image is free of motion blur,which comes at the expense of long acquisition times.In order to speed up the acquisition process,especially for large scanning areas,such as pathology slides,we developed an acquisition method in which the data is acquired continuously while the stage is moving at high speeds.Using generative adversarial networks(GANs),we demonstrate this ultra-fast imaging approach,referred to as GANscan,which restores sharp images from motion blurred videos.GANscan allows us to complete image acquisitions at 30x the throughput of stop-and-stare systems.This method is implemented on a Zeiss Axio Observer Z1 microscope,requires no specialized hardware,and accomplishes successful reconstructions at stage speeds of up to 5000 μm/s.We validate the proposed method by imaging H&E stained tissue sections.Our method not only retrieves crisp images from fast,continuous scans,but also adjusts for defocusing that occurs during scanning within+/-5 μm.Using a consumer GPU,the inference runs at<20 ms/image. | Michael John Fanous Gabriel Popescu | 2022 | Light(Science & Applications)2022，11，10： | 1 |
| 13 | The conflicting logics of cross-border reterritoria- lization:Geopolitics of Euroregions in Eastern Europe显示文摘 | Gabriel Popescu | 2008 | Political Geography2008，27，： | 1 |
| 14 | The Risk Management of Companies From Timis County Involved in International Business显示文摘 | Gabriel Bizoi Alexandra Popescu | 2011 | Chinese Business Review2011，10，6： | 0 |
| 15 | Gabor’s holography at sea显示文摘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 microscopy1.While the method has not produced an impact in its originally intended field,it opened a new direction,known as holography,in optics.Gabor’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. | Gabriel Popescu | 2019 | Light(Science & Applications)2019，8，1： | 0 |
| 16 | Large-scale phase retrieval显示文摘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 field1.As a result,knowledge about the phase of the scattered field is necessary for solving this inverse problem with a unique solution.However,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 reconstruction.This 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 space.While 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 successful.This is clear,for example,from the following:Two different structures were predicted for the mineral bixbyite,one by L.Pauling,the other by W.H.Zachariasen.It is not known which,if either,is correct.”(Chapter 7 in ref.2). | Gabriel Popescu | 2021 | Light(Science & Applications)2021，10，10： | 0 |
| 17 | 三维弹塑性滚动接触分析的工程模型显示文摘符号说明aH,bH:赫兹接触椭圆的长半轴,短半轴,m az,ay:网格间距,m | GABRIEL POPESCU | 2007 | 国外轴承技术2007，，2： | 0 |
| 18 | Endoscopic ultrasound-guided fine-needle aspiration pancreatic adenocarcinoma samples yield adequate DNA for next-generation sequencing:A cohort analysis显示文摘BACKGROUND Genetic tests are increasingly performed for the management of unresectable pancreatic cancer.For genotyping aimed samples current guidelines recommend using core specimens,although based on moderate quality evidence.However,in clinical practice among the endoscopic ultrasound(EUS) guided tissue acquisition methods,fine needle aspiration(FNA) is the most widely performed.AIM To assess the adequacy for next generation sequencing(NGS) of the DNA yielded from EUS-FNA pancreatic adenocarcinoma(PDAC) samples.METHODS Between November 2018 and December 2021,105 patients with PDAC confirmed by EUS-FNA were included in the study at our tertiary gastroenterology center.Either 22 gauge(G) or 19G FNA needles were used.One pass was dedicated to DNA extraction.DNA concentration and purity(A260/280,A260/230) were assessed by spectrophotometry.We 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 respectively.Moreover,we compared DNA purity parameters across the different DNA yield categories.RESULTS Our cohort included 49% male patients,aged 67.02 ± 8.38 years.The 22G needle was used in 71%of the cases.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.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 amplicon based NGS.Samples with DNA yield > 100 ng had significantly higher A260/280(1.89 ± 0.32 vs 1.34 ± 0.42,P = 0.013).Tumor characteristics were not corelated with the DNA parameters.CONCLUSION EUS-FNA PDAC samples yield DNA adequate for subsequent NGS.DNA amount was similar between 22G and 19G FNA needles.DNA purity parameters may vary indirectly with needle size. | 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 | 2023 | World Journal of Gastroenterology2023，29，18： | 0 |
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