Publications by authors named "Wubin Weng"

13 Publications

  • Page 1 of 1

Value of C-Choline PET/CT-Based Multi-Metabolic Parameter Combination in Distinguishing Early-Stage Prostate Cancer From Benign Prostate Diseases.

Front Oncol 2020 1;10:600380. Epub 2021 Feb 1.

Department of Urology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.

Purpose: The most common disadvantage of C-choline positron emission tomography and computed tomography (PET/CT) in diagnosing early-stage prostate cancer (PCa) is its poor sensitivity. In spite of many efforts, this imaging modality lacks the ideal parameter of choline metabolism for the diagnosis of PCa, and the single metabolic parameter, that is, maximal standardized uptake value (SUVmax), based on this imaging modality is insufficient. C-choline PET/CT-based multi-metabolic parameter combination can help break this limitation.

Materials And Methods: Before surgery, SUVmax of choline, which is the most common metabolic parameter of C-choline PET/CT, mean standardized uptake value (SUVmean), prostate-to-muscle (P/M) ratio, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) from 74 patients with histologically proven PCa were quantified. A total of 13 patients with focal chronic prostatitis without severe features and 30 patients with benign prostate hyperplasia were used for comparison. Univariable and multivariable analyses were performed to compare the patient characteristics and metabolic parameters of C-choline PET/CT. The performance of single parameters and the combination of parameters were assessed by using logistic regression models.

Results: The comparable c-statistics, which mean the area under the ROC curve in the logistic regression model, of SUVmax, SUVmean, and P/M ratio are 0.657, 0.667, and 0.672, respectively. The c-statistic significantly rose to 0.793 when SUVmax and SUVmean were combined with the P/M ratio. This parameter combination performed the best for PCa cases with all biochemical recurrence risks and for PCa patients grouped by different risk. The greatest improvement over a single parameter, such as P/M ratio, was noted in the group of low-risk PCa, with values of 0.535 to 0.772 for the three-parameter combination. And in the histopathological level, the Ki-67 index is positively correlated with the P/M ratio (r=0.491, =0.002).

Conclusion: P/M ratio is a more ideal parameter than SUVmax as a single parameter in early-stage PCa diagnosis. According to our data, the combination of SUVmax, SUVmean, and P/M ratio as a composite parameter for diagnosis of early stage PCa improves the diagnostic accuracy of C-choline PET/CT.
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http://dx.doi.org/10.3389/fonc.2020.600380DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7882704PMC
February 2021

Ultraviolet Absorption Cross-Sections of Ammonia at Elevated Temperatures for Nonintrusive Quantitative Detection in Combustion Environments.

Appl Spectrosc 2021 Feb 2:3702821990445. Epub 2021 Feb 2.

Division of Combustion Physics, 5193Lund University, Lund, Sweden.

Ammonia (NH) is regarded as an important nitrogen oxides (NOx) precursor and also as an effective reductant for NOx removal in energy utilization through combustion, and it has recently become an attractive non-carbon alternative fuel. To have a better understanding of thermochemical properties of NH, accurate in situ detection of NH in high temperature environments is desirable. Ultraviolet (UV) absorption spectroscopy is a feasible technique. To achieve quantitative measurements, spectrally resolved UV absorption cross-sections of NH in hot gas environments at different temperatures from 295 K to 590 K were experimentally measured for the first time. Based on the experimental results, vibrational constants of NH were determined and used for the calculation of the absorption cross-section of NH at high temperatures above 590 K using the PGOPHER software. The investigated UV spectra covered the range of wavelengths from 190 nm to 230 nm, where spectral structures of the transition of NH in the umbrella bending mode, , were recognized. The absorption cross-section was found to decrease at higher temperatures. For example, the absorption cross-section peak of the (6, 0) vibrational band of NH decreases from ∼2 × 10 to ∼0.5 × 10 cm/molecule with the increase of temperature from 295 K to 1570 K. Using the obtained absorption cross-section, in situ nonintrusive quantification of NH in different hot gas environments was achieved with a detection limit varying from below 10 parts per million (ppm) to around 200 ppm as temperature increased from 295 K to 1570 K. The quantitative measurement was applied to an experimental investigation of NH combustion process. The concentrations of NH and nitric oxide (NO) in the post flame zone of NH-methane (CH)-air premixed flames at different equivalence ratios were measured.
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http://dx.doi.org/10.1177/0003702821990445DOI Listing
February 2021

Dual-laser-induced Breakdown Thermometry via Sound Speed Measurement:A New Procedure for Improved Spatiotemporal Resolution.

Sensors (Basel) 2020 May 14;20(10). Epub 2020 May 14.

Division of Combustion Physics, Lund University, P.O. Box 118, Lund 22100, Sweden.

Measurement of acoustic waves from laser-induced breakdown has been developed as gas thermometry in combustion atmospheres. In the measurement, two laser-induced breakdown spots are generated and the local gas temperature between these two spots is determined through the measurement of the sound speed between them. In the previous study, it was found that the local gas breakdown can introduce notable system uncertainty, about 5% to the measured temperature. To eliminate the interference, in present work, a new measurement procedure was proposed, where two individual laser pulses with optimized firing order and delay time were employed. With the new measurement procedure, the system uncertainty caused by local gas breakdown can be largely avoided and the temporal and spatial resolutions can reach up to 0.5 ms and 10 mm, respectively. The improved thermometry, dual-laser-induced breakdown thermometry (DLIBT), was applied to measure temperatures of hot flue gases provided by a multijet burner. The measured temperatures covering the range between 1000 K and 2000 K were compared with the ones accurately obtained through the two-line atomic fluorescence (TLAF) thermometry with a measurement uncertainty of ~3%, and a very good agreement was obtained.
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http://dx.doi.org/10.3390/s20102803DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7285112PMC
May 2020

Quantitative SO Detection in Combustion Environments Using Broad Band Ultraviolet Absorption and Laser-Induced Fluorescence.

Anal Chem 2019 08 8;91(16):10849-10855. Epub 2019 Aug 8.

Division of Combustion Physics , Lund University , P.O. Box 118, Lund SE-221 00 , Sweden.

Spectrally resolved ultraviolet (UV) absorption cross sections of SO in combustion environments at temperatures from 1120 to 1950 K were measured for the first time in well-controlled conditions through applying broad band UV absorption spectroscopy in specially designed one-dimensional laminar flat flames. The temperature was observed to have a significant effect on the absorption cross-section profiles at wavelength shorter than 260 nm, while at the longer wavelength side, the absorption cross-section profiles have much less dependence on temperature. The absorption cross section at 277.8 nm with a value of 0.68 × 10 cm/molecule was suggested for the evaluation of the SO concentration because of the weak dependence on temperature. To make spatially resolved measurements, laser-induced fluorescence (LIF) of SO excited by a 266 nm laser was investigated. Spectrally resolved LIF signal was analyzed at different temperatures. The LIF signal showed strong dependence on temperature, which can potentially be used for temperature measurements. At elevated temperatures, spatially resolved LIF SO detection up to a few ppm sensitivity was achieved. Combining UV broad band absorption spectroscopy and LIF, highly sensitive and spatially resolved quantitative measurements of SO in the combustion environment can be achieved.
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http://dx.doi.org/10.1021/acs.analchem.9b02505DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6776380PMC
August 2019

Ultraviolet Absorption Cross Sections of KOH and KCl for Nonintrusive Species-Specific Quantitative Detection in Hot Flue Gases.

Anal Chem 2019 04 18;91(7):4719-4726. Epub 2019 Mar 18.

Division of Combustion Physics , Lund University , P.O. Box 118, SE-221 00 , Lund , Sweden.

An understanding of potassium chemistry in energy conversion processes supports the development of complex biomass utilization with high efficiency and low pollutant emissions. Potassium exists mainly as potassium hydroxide (KOH), potassium chloride (KCl), and atomic potassium (K) in combustion and related thermochemical processes. We report, for the first time, the measurement of the ultraviolet (UV) absorption cross sections of KOH and KCl at temperatures between 1300 K and 1800 K, using a newly developed method. Using the spectrally resolved UV absorption cross sections, the concentrations of KOH and KCl were measured simultaneously. In addition, we measured the concentrations of atomic K using tunable diode laser absorption spectroscopy, both at 404.4 and 769.9 nm. The 404.4 nm line was utilized to expand the measurement dynamic range to higher concentrations. A constant amount of KCl was seeded into premixed CH/air flames with equivalence ratios varied from 0.67 to 1.32, and the concentrations of KOH, KCl, and atomic K in the hot flue gas were measured nonintrusively. The results indicate that these techniques can provide comprehensive data for quantitative understanding of the potassium chemistry in biomass combustion/gasification.
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http://dx.doi.org/10.1021/acs.analchem.9b00203DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6458966PMC
April 2019

Gas Temperature Measurement Using Differential Optical Absorption Spectroscopy (DOAS).

Appl Spectrosc 2018 Jul 18;72(7):1014-1020. Epub 2018 Jun 18.

2 Division of Combustion Physics, Lund University, Lund, Sweden.

A nonintrusive method for flow gas temperature measurement using differential optical absorption spectroscopy (DOAS) was demonstrated. A temperature-dependent spectra (TDS) originated from the DOAS spectra of sulfur dioxide (SO) in the wavelength range of 276-310 nm was introduced, and the relationship between the TDS and the temperature was built through experimental calibration process. This relationship is found to be independent of SO concentration and can be used for temperature measurements. The experimental results indicated that the precision of the TDS method is < ± 0.3% for SO concentrations higher than 150 ppm with the optical path length of 170 mm. For lower concentrations, the precision is estimated to be ± 0.4% at 1 ppm. The relative deviation between the temperature measured by the TDS method and that measured by a thermocouple is within 3% in the temperature range of 298-750 K, and the TDS method has a quicker response to the fast-changing temperature than the thermocouple.
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http://dx.doi.org/10.1177/0003702818760864DOI Listing
July 2018

Spectrally Resolved Ultraviolet (UV) Absorption Cross-Sections of Alkali Hydroxides and Chlorides Measured in Hot Flue Gases.

Appl Spectrosc 2018 Sep 28;72(9):1388-1395. Epub 2018 Mar 28.

1 Division of Combustion Physics, Lund University, Sweden.

Spectrally resolved ultraviolet (UV) absorption cross-sections of gas-phase sodium chloride (NaCl), potassium hydroxide (KOH), and sodium hydroxide (NaOH) were measured, for the first time, in hot flue gases at different temperatures. Homogenous gas-phase NaCl, KCl (potassium chloride), NaOH, and KOH at temperatures 1200 K, 1400 K, 1600 K, and 1850 K were prepared in the post-flame zone of laminar flames by seeding nebulized droplets out of aqueous solution of corresponding alkali species. The amount of droplets seeded into the flame was kept constant, so the relative concentration of different alkali species can be derived. The broadband UV absorption cross-section of KCl vapor reported by Leffler et al. was adopted to derive the absorption cross-section curves of NaCl, NaOH, and KOH with the corresponding measured spectrally resolved absorbance spectra. No significant changes in the spectral structures in the absorption cross-sections were found as the temperature varied between 1200 K and 1850 K, except for NaOH at around 320 nm. The difference between the absorption spectral curves of alkali chlorides and hydroxides is significant at wavelengths above 300 nm, which thus can be used to distinguish and obtain the concentrations of alkali chlorides and hydroxides in the broadband UV absorption measurements.
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http://dx.doi.org/10.1177/0003702818763819DOI Listing
September 2018

Spatially Resolved Temperature Measurements Above a Burning Wood Pellet Using Diode Laser-Based Two-Line Atomic Fluorescence.

Appl Spectrosc 2018 Jun 7;72(6):964-970. Epub 2017 Dec 7.

Division of Combustion Physics, Lund University, Lund, Sweden.

Diode laser-based two-line atomic fluorescence (TLAF) thermometry applied to flames of combusting wood pellets is demonstrated. The temperature above burning wood pellets placed in the hot product gas of gallium seeded laminar flames is measured. The calibration-free technique provides spatially resolved temperatures in one dimension with sufficient temporal resolution to resolve all combustion stages of a pellet, even in highly sooting flames. The temperature above a burning pellet was found to decrease due to the release of volatile gases and the accuracy and precision of the technique is assessed at flame temperatures.
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http://dx.doi.org/10.1177/0003702817746996DOI Listing
June 2018

A novel multi-jet burner for hot flue gases of wide range of temperatures and compositions for optical diagnostics of solid fuels gasification/combustion.

Rev Sci Instrum 2017 Apr;88(4):045104

Division of Combustion Physics, Lund University, P.O. Box 118, SE221 00 Lund, Sweden.

A novel multi-jet burner was built to provide one-dimensional laminar flat flames with a wide range of variable parameters for multipurpose quantitative optical measurements. The burner is characterized by two independent plenum chambers, one supporting a matrix of 181 laminar jet flames and the other supporting a co-flow from a perforated plate with small holes evenly distributed among the jets. A uniform rectangular burned gas region of 70 mm × 40 mm can be generated, with a wide range of temperatures and equivalence ratios by controlling independently the gas supplies to the two plenum chambers. The temperature of the hot gas can be adjusted from 1000 K to 2000 K with different flame conditions. The burner is designed to seed additives in gas or liquid phase to study homogeneous reactions. The large uniform region can be used to burn solid fuels and study heterogeneous reactions. The temperature was measured using two-line atomic fluorescence thermometry and the temperature profile at a given height above the burner was found to be flat. Different types of optical diagnostic techniques, such as line of sight absorption or laser-induced fluorescence, can be easily applied in the burner, and as examples, two typical measurements concerning biomass combustion are demonstrated.
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http://dx.doi.org/10.1063/1.4979638DOI Listing
April 2017

Quantitative Imaging of Ozone Vapor Using Photofragmentation Laser-Induced Fluorescence (LIF).

Appl Spectrosc 2017 Jul 14;71(7):1578-1585. Epub 2017 Feb 14.

1 Division of Combustion Physics, Lund University, Lund, Sweden.

In the present work, the spectral properties of gaseous ozone (O) have been investigated aiming to perform quantitative concentration imaging of ozone by using a single laser pulse at 248 nm from a KrF excimer laser. The O molecule is first photodissociated by the laser pulse into two fragments, O and O. Then the same laser pulse electronically excites the O fragment, which is vibrationally hot, whereupon fluorescence is emitted. The fluorescence intensity is found to be proportional to the concentration of ozone. Both emission and absorption characteristics have been investigated, as well as how the laser fluence affects the fluorescence signal. Quantitative ozone imaging data have been achieved based on calibration measurements in known mixtures of O. In addition, a simultaneous study of the emission intensity captured by an intensified charge-coupled device (ICCD) camera and a spectrograph has been performed. The results show that any signal contribution not stemming from ozone is negligible compared to the strong fluorescence induced by the O fragment, thus proving interference-free ozone imaging. The single-shot detection limit has been estimated to ∼400 ppm. The authors believe that the presented technique offers a valuable tool applicable in various research fields, such as plasma sterilization, water and soil remediation, and plasma-assisted combustion.
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http://dx.doi.org/10.1177/0003702817691528DOI Listing
July 2017

Diode laser-based thermometry using two-line atomic fluorescence of indium and gallium.

Appl Phys B 2017 7;123(12):278. Epub 2017 Nov 7.

Lund University, Lund, Sweden.

A robust and relatively compact calibration-free thermometric technique using diode lasers two-line atomic fluorescence (TLAF) for reactive flows at atmospheric pressures is investigated. TLAF temperature measurements were conducted using indium and, for the first time, gallium atoms as temperature markers. The temperature was measured in a multi-jet burner running methane/air flames providing variable temperatures ranging from 1600 to 2000 K. Indium and gallium were found to provide a similar accuracy of ~ 2.7% and precision of ~ 1% over the measured temperature range. The reliability of the TLAF thermometry was further tested by performing simultaneous rotational CARS measurements in the same experiments.
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http://dx.doi.org/10.1007/s00340-017-6855-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6956933PMC
November 2017

GeneWays: a system for extracting, analyzing, visualizing, and integrating molecular pathway data.

J Biomed Inform 2004 Feb;37(1):43-53

Columbia Genome Center, Columbia University, New York, NY 10032, USA.

The immense growth in the volume of research literature and experimental data in the field of molecular biology calls for efficient automatic methods to capture and store information. In recent years, several groups have worked on specific problems in this area, such as automated selection of articles pertinent to molecular biology, or automated extraction of information using natural-language processing, information visualization, and generation of specialized knowledge bases for molecular biology. GeneWays is an integrated system that combines several such subtasks. It analyzes interactions between molecular substances, drawing on multiple sources of information to infer a consensus view of molecular networks. GeneWays is designed as an open platform, allowing researchers to query, review, and critique stored information.
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http://dx.doi.org/10.1016/j.jbi.2003.10.001DOI Listing
February 2004

Learning anchor verbs for biological interaction patterns from published text articles.

Int J Med Inform 2002 Dec;67(1-3):19-32

Department of Computer Science, Columbia University, 1214 Amsterdam Avenue, New York, NY 10027 USA.

Much of knowledge modeling in the molecular biology domain involves interactions between proteins, genes, various forms of RNA, small molecules, etc. Interactions between these substances are typically extracted and codified manually, increasing the cost and time for modeling and substantially limiting the coverage of the resulting knowledge base. In this paper, we describe an automatic system that learns from text interaction verbs; these verbs can then form the core of automatically retrieved patterns which model classes of biological interactions. We investigate text features relating verbs with genes and proteins, and apply statistical tests and a logistic regression statistical model to determine whether a given verb belongs to the class of interaction verbs. Our system, AVAD, achieves over 87% precision and 82% recall when tested on an 11 million word corpus of journal articles. In addition, we compare the automatically obtained results with a manually constructed database of interaction verbs and show that the automatic approach can significantly enrich the manual list by detecting rarer interaction verbs that were omitted from the database.
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http://dx.doi.org/10.1016/s1386-5056(02)00054-0DOI Listing
December 2002