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Hyper spectral resolution stimulated Raman spectroscopy with amplified fs pulse bursts

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Light(Science & Applications) 2024年第3期13卷 566-576页

作者： Hongtao Hu Tobias Flöry Vinzenz Stummer Audrius Pugzlys Markus Zeiler Xinhua Xie Aleksei Zheltikov andrius Baltuška Photonics Institute Technische Universität WienGußhausstraße 27-29Vienna A-1040Austria SwissFEL Paul Scherrer InstituteVilligen PSI 5232Switzerland Institute for Quantum Science and Engineering Department of Physics and AstronomyTexas A&M UniversityCollege StationTX 77843USA

We present a novel approach for Stimulated Raman Scattering(SRS)spectroscopy in which a hyper spectral resolution and high-speed spectral acquisition are achieved by employing amplified offset-phase controlled fs-pulse *** investigate the method by solving the coupled non-linear Schrödinger equations and validate it by numerically characterizing SRS in molecular nitrogen as a model *** spectral resolution of the method is found to be determined by the inverse product of the number of pulses in the burst and the intraburst pulse *** SRS spectrum is obtained through a motion-free scanning of the offset phase that results in a sweep of the Raman-shift *** to high spectral resolution and fast motion-free scanning the technique is beneficial for a number SRS-based applications such as gas sensing and chemical analysis.

关键词： compound spectral resolution

Generation of millijoule-level sub-5 fs violet laser pulses

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High Power Laser Science and Engineering 2024年第2期12卷 33-40页

作者： Xinhua Xie Yi Hung Yunpei Deng Adrian L.Cavalieri andrius Baltuška Steven L.Johnson SwissFEL Paul Scherrer InstituteVilligen PSISwitzerland Photonics Institute Technische Universität WienViennaAustria Institute of Applied Physics University of BernBernSwitzerland Institute for Quantum Electronics Physics DepartmentETH ZurichZurichSwitzerland

We demonstrate the generation,spectral broadening and post-compression of second harmonic pulses using a thin beta barium borate(BBO)crystal on a fused-silica substrate as the nonlinear interaction *** combining second harmonic generation in the BBO crystal with self-phase modulation in the fused-silica substrate,we efficiently generate millijoule-level broadband violet pulses from a single optical *** second harmonic spectrum covers a range from long wave ultraviolet(down to 310 nm)to visible(up to 550 nm)with a bandwidth of 65 ***,we compress the second harmonic beam to a duration of 4.8 fs with a pulse energy of 0.64 mJ(5 fs with a pulse energy of 1.05 mJ)using chirped *** all-solid free-space apparatus is compact,robust and pulse energy scalable,making it highly advantageous for generating intense second harmonic pulses from near-infrared femtosecond lasers in the sub-5 fs regime.

关键词： post-compression second harmonic generation self-phase modulation supercontinuum generation

Determining exact survival probability by setting discrete random variables in E. Sparre Andersen’s model

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Probability, Uncertainty and Quantitative Risk 2023年第4期8卷 445-462页

作者： andrius Grigutis Institute of Mathematics Vilnius UniversityNaugarduko 24VilniusLT-03225Lithuania

In this work,we propose an alternative to the Pollaczek-Khinchine formula for the ultimate time survival(or ruin)probability calculation in exchange for a few assumptions on the random variables that generate the renewal risk *** precisely,we demonstrate the expressibility of the distribution function n P(sup n≥1^(n)∑_(i=1)(X_(i)-cθ_(i))0 X cθindependent copies of X and respectively,wherein,and are independent,θnonnegative,and *** also assume that the support of is *** illustrate the applicability of the proven theoretical statements we present a few numerical outputs when the mentioned random variables adopt some particular distributions.

关键词： Ruin theory Renewal theory Queueing theory Random walk Survival probability Generating function Pollaczek–Khinchine formula Initial values

Genome-wide markers for seed yield and disease resistance in perennial ryegrass

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The Crop Journal 2022年第2期10卷 508-514页

作者： Kristina Jaškune Vilma Kemešyte andrius Aleliūnas Grazina Statkeviciute Institute of Agriculture Lithuanian Research Centre for Agriculture and Forestry(LAMMC)Instituto av.1Akademija LT-58344Lithuania

The market success of perennial ryegrass(Lolium perenne L.) cultivars depends on sufficient seed production, as they are propagated by seed. However, breeding for high quality forage production reduces seed yield, and breaking the negative correlation would help to overcome the problem. The foliar disease crown rust is another factor affecting reproductive capacity and thereby seed yield. We evaluated seed yield-related traits and resistance to crown rust in a collection of commercial cultivars and ecotypes of perennial ryegrass and identified genome-wide markers associated with the traits. The study revealed high variation between the ecotype and cultivar groups as well as between years. A genome-wide association study identified 17 DNA single-nucleotide polymorphisms(SNPs) of which eight were associated with crown rust and nine with flag-leaf length. The SNP markers were located within or near predicted genes functioning in defense against pathogens. The identified genes are strong candidates for a further in-depth functional study to continue unravel determination of leaf architecture and crown rust resistance in perennial ryegrass.

关键词： Crown rust Puccinia coronata f.sp.lolli Flag-leaf length Genome-wide association study(GWAS) Seed yield Lolium perenne L.

Fourier-Limited Attosecond Pulse from High Harmonic GenerationAssistedbyUlitrafast MagneticFields

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Ultrafast Science 2023年第5期3卷 51-59页

作者： Rodrigo Martin-Hernandez Hongtao Hu andrius Baltuska Luis Plaja Carlos Hernandez-Garcia'I Grupo de Investigacion en Aplicaciones del Lasery Fotonica Departamento de Fisica AplicadaUniversidad de SalamancaE-37008 SalamancaSpain Photonics Institute Technische Universitat WienA-1040 ViennaAustria

One of the main constraints for reducing the temporal duration of attosecond pulses is the attochirp inherent to the process of high-order harmonic generation(HHG).Though the attochirp can be compensated in the extreme-ultraviolet using dispersive materials,this is unfeasible toward x-rays,where the shortest attosecond or even sub-attosecond pulses could be *** theoretically demonstrate that HHG driven by a circularly polarized infrared pulse while assisted by an strong oscillating ultrafast intense magnetic field enables the generation of few-cycle Fourier-limited few attosecond *** such a novel scenario,the magnetic field transversally confines the ionized electron during the HHG process,analogously to a nanowire *** the electron is ionized,the transverse electron dynamics is excited by the magnetic field,acting as a high-energy reservoir to be released in the form of phase-locked spectrally wide high-frequency harmonic radiation during the electron recollision with the parent *** addition,the transverse breathing dynamics of the electron wavepacket,introduced by the magnetic trapping,strongly modulates the recollision efficiency of the electronic trajectories,thus the attosecond pulse *** aftermath is the possibility of producing high-frequency(hundreds of eV)attosecond isolated few-cycle pulses,almost Fourier *** isolated intense magnetic fields considered in our simulations,of tens of kT,can be produced in finite spatial volumes considering structured beams or stationary configurations of counter-propagating state-of-the-art multi-terawatt/petawatt lasers.

关键词： harmonic trapping intense

Channel-resolved subcycle interferences of electron wave packets emitted from H_(2) in two-color laser fields

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High Power Laser Science and Engineering 2016年第4期4卷 1-7页

作者： Xinhua Xie Stefan Roither Daniil Kartashov Li Zhang andrius Baltuska Markus Kitzler Photonics Institute Technische Universitat Wien Institute of Theoretical Chemistry University of Vienna

We report on the observation of subcycle interferences of electron wave packets released during strong field ionization of H_2 with cycle-shaped two-color laser fields. With a reaction microscope we measure three-dimensional momentum distributions of photoelectrons correlated with either H_2^+ or protons within different energy ranges generated by dissociation of H_2^+. We refer to these different types of photoelectrons as channels. Our results show that the subcycle interference structures of electron wave packets are very sensitive to the cycle shape of the two-color laser field. We explain this behavior by the dependence of the ionization time within an optical cycle on the shape of the laser field cycle. The subcycle interference structures can be further used to obtain insight into the subcycle dynamics of molecules during strong field interaction.

关键词： molecular dynamics strong field ionization wave packet interference

Value of adipokines in predicting the severity of acute pancreatitis:Comprehensive review

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World Journal of Gastroenterology 2012年第45期18卷 6620-6627页

作者： andrius Karpavicius Zilvinas Dambrauskas Audrius Sileikis Dalius Vitkus Kestutis Strupas Clinic of Gastroenterology NephrologyUrology and SurgeryFaculty of MedicineVilnius UniversityLT-01513 VilniusLithuania Center of Abdominal Surgery Vilnius University Hospital "Santariskiu klinikos"LT-08661 VilniusLithuania Department of Surgery Medical AcademyLithuanian University of Health SciencesLT-50009 KaunasLithuania Institute for Research of Digestive System Medical AcademyLithuanian University of Health SciencesLT-50009 KaunasLithuania Department of Physiology BiochemistryMicrobiologyand Laboratory MedicineFaculty of MedicineVilnius UniversityLT-01513 VilniusLithuania

AIM:To analyze the prognostic value of adipokines in predicting the course,complications and fatal outcome of acute pancreatitis(AP).METHODS:We performed the search of PubMed database and the systemic analysis of the literature for both experimental and human studies on prognostic value of adipokines in AP for period *** the papers that described the use of adipokines for prediction of severity and/or complications of AP were selected for further *** article had to contain information about the levels of measured adipokines,diagnosis and verification of AP,to specify presence of pancreatic necrosis,organ dysfunction and/or mortality *** the very beginning,study was carried out adhering to the PRISMA checklist and flowchart for systemic *** assess quality of all included human studies,the Quality Assessment of Diagnostic Accuracy Studies tool was *** of the high heterogeneity between the studies,it was decided to refrain from the statistical processing or meta-analysis of the available ***:Nine human and three experimental studies were included into *** experimental studies significant differences between leptin concentrations at 24 and 48 h in control,acute edematous and acute necrotizing pancreatitis groups were found(P = 0.027 and P < 0.001).In human studies significant differences between leptin and resitin concentrations in control and acute pancreatitis groups were found.1-3 d serum adiponectin threshold of 4.5 μg/mL correctly classified the severity of 81% of patients with *** threshold yielded a sensitivity of 70%,specificity 85%,positive predictive value 64%,negative predictive value88%(area under curve 0.75).Resistin and visfatin concentrations differ significantly between mild and severe acute pancreatitis groups,they correlate with severity of disease,need for interventions and *** adipokines are good markers for parapancreatic necrosis and the cut-off values of 11.9 ng/mL and 1.8 ng/

关键词：重症急性胰腺炎细胞因子严重程度预测值高脂肪急性坏死性胰腺炎审查价值

Endogenous motion of liver correlates to the severity of portal hypertension

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World Journal of Gastroenterology 2020年第38期26卷 5836-5848页

作者： Sigita Gelman andrius Sakalauskas Romanas Zykus andrius Pranculis Rytis Jurkonis Irma Kuliavienė Arūnas Lukoševičius Limas Kupčinskas Juozas Kupčinskas Department of Gastroenterology Medical AcademyLithuanian University of Health SciencesKaunas 44307Lithuania Biomedical Engineering Institute Kaunas University of TechnologyKaunas 51423Lithuania Department of Radiology Medical AcademyLithuanian University of Health SciencesKaunas 44307Lithuania Institute for Digestive Research and Department of Gastroenterology Medical AcademyLithuanian University of Health SciencesKaunas 44307Lithuania

BACKGROUND Degree of portal hypertension(PH)is the most important prognostic factor for the decompensation of liver cirrhosis and death,therefore adequate care for patients with liver cirrhosis requires timely detection and evaluation of the presence of clinically significant PH(CSPH)and severe PH(SPH).As the most accurate method for the assessment of PH is an invasive direct measurement of hepatic venous pressure gradient(HVPG),the search for non-invasive methods to diagnose these conditions is actively *** To evaluate the feasibility of parameters of endogenously induced displacements and strain of liver to assess degree of *** Of 36 patients with liver cirrhosis and measured HVPG were included in the casecontrol *** motion of the liver was characterized by derived parameters of region average tissue displacement signal(dantero,dretro,dRMS)and results of endogenous tissue strain imaging using specific radiofrequency signal processing *** endogenous strainμand standard deviationσof strain were assessed in the regions of interest(ROI)(1 cm×1 cm and 2 cm×2 cm in size)and different frequency subbands of endogenous motion(0-10 Hz and 10-20 Hz).RESULTS Four parameters showed statistically significant(P<0.05)correlation with HVPG *** strongest correlation was obtained for the standard deviation of strain(estimated at 0-10 Hz and 2 cm×2 cm ROI size).Three parameters showed statistically significant differences between patient groups with CSPH,but only dretro showed significant results in SPH *** to ROC analysis area under the curve(AUC)of theσROI[0…10Hz,2 cm×2 cm]parameter reached 0.71(P=0.036)for the diagnosis of CSPH;with a cut-off value of 1.28μm/cm providing 73%sensitivity and 70%*** for the diagnosis of CSPH forμROI[0…10Hz,1 cm×1 cm]was 0.78(P=0.0024);with a cut-off value of 3.92μm/cm providing 73%sensitivity and 80%*** parameter had an AUC of 0.86(P=0.0001)for the diagnos

关键词： Portal hypertension Endogenous motion Strain elastography Hepatic venous pressure gradient Radiofrequency parameters

Multidisciplinary diagnostic dilemma in differentiating Madelung’s disease—the value of superb microvascular imaging technique:A case report

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World Journal of Clinical Cases 2021年第21期9卷 6145-6154页

作者： Goda Seskute Austeja Dapkute Dominyka Kausaite Sandra Strainiene andrius Talijunas Irena Butrimiene Clinic of Rheumatology Orthopaedics Traumatologyand Reconstructive SurgeryInstitute of Clinical MedicineFaculty of MedicineVilnius UniversityVilnius 01513Lithuania Clinic of Neurology and Neurosurgery Institute of Clinical MedicineFaculty of MedicineVilnius UniversityVilnius 01513Lithuania Faculty of Medicine Vilnius UniversityVilnius 01513Lithuania Clinic of Gastroenterology Nephrourology and SurgeryInstitute of Clinical MedicineFaculty of MedicineVilnius UniversityVilnius 01513Lithuania Institute of Dentistry Faculty of MedicineVilnius UniversityVilnius 01512Lithuania

BACKGROUND Madelung’s disease,also known as multiple symmetrical lipomatosis,is a rare,underrecognized disorder of fat metabolism that results in unusual accumulation of subcutaneous fat deposits around the neck,shoulders,upper arms,trunk,hips,and upper *** case demonstrates the importance of differential diagnosis and the value of a superb microvascular imaging technique for suspecting and confirming Madelung’s *** diagnosis and alcohol abstinence could prevent the progression of growing fatty masses and prevent *** SUMMARY A 62-year-old male was admitted to the Rheumatology center complaining of symmetric subcutaneous tumors in the area of the parotid and submandibular salivary glands,small soft masses in the occiput and upper third of the forearm,rashes on calves.A high titer of rheumatoid factor and low concentrations of serum complements were *** high-end ultrasound and magnetic resonance imaging examinations of all affected areas of the soft tissues showed predominantly adipose tissue(lipomas)without suspicion of *** biopsy from the small salivary gland revealed no *** evaluating the patient’s clinical presentation(symmetrical lipomatosis,cirrhosis,gynecomastia,anemia,hyperuricemia),Madelung’s disease,type I,along with the psoriatic rash and psoriatic arthritis and secondary liver cirrhosis were *** Madelung’s disease consists of many co-occurring disorders imitating and overlapping with other *** is the first choice for suspecting and confirming symmetrical lipomatosis.

关键词： Madelung’s disease Multiple symmetrical lipomatosis Cirrhosis Salivary gland tumors Superb microvascular imaging Case report