Quality Improvement of Sample Collection Increases the Diagnostic Accuracy of Quantitative Fecal Immunochemical Test in Colorectal Cancer Screening: A Pilot Study.

The diagnostic efficiency of the quantitative fecal immunochemical test (qFIT) has large variations in colorectal cancer (CRC) screening. We aimed to explore whether the practical sample collection operant training could improve the diagnostic accuracy of the qFIT in CRC screening. Moderate-/high-risk individuals aged 50-75 years old were invited to participate in a prospective observational study between July 2020 and March 2021.

Development and Validation of an Automatic Image-Recognition Endoscopic Report Generation System: A Multicenter Study.

Introduction: Conventional gastrointestinal (GI) endoscopy reports written by physicians are time consuming and might have obvious heterogeneity or omissions, impairing the efficiency and multicenter consultation potential. We aimed to develop and validate an image recognition-based structured report generation system (ISRGS) through a multicenter database and to assess its diagnostic performance.

Methods: First, we developed and evaluated an ISRGS combining real-time video capture, site identification, lesion detection, subcharacteristics analysis, and structured report generation.

Zinc chelator TPEN induces pancreatic cancer cell death through causing oxidative stress and inhibiting cell autophagy.

The essential trace element zinc (Zn) is widely required in cellular functions, and abnormal Zn homeostasis causes a variety of health problems including immunodeficiency and sensory dysfunctions. Previous studies had shown that Zn availability was also important for tumor growth and progression. The aim of the present study was to investigate the potential mechanisms of N,N,N,N-Tetrakis(2-pyridylmethyl)-ethylenediamine (TPEN) (a membrane permeable zinc chelator) induced pancreatic cancer cell death.

In Situ Underwater Laser-Induced Breakdown Spectroscopy Analysis for Trace Cr(VI) in Aqueous Solution Supported by Electrosorption Enrichment and a Gas-Assisted Localized Liquid Discharge Apparatus.

Traditional laser-induced breakdown spectroscopy (LIBS) always fails to directly detect target in aqueous solution due to rapid quenching of emitted light and adsorption of pulse energy by surrounding water. A method is proposed for the in situ underwater LIBS analysis of Cr(VI) in aqueous solution freed from the common problems mentioned above by combining a gas-assisted localized liquid discharge apparatus with electrosorption for the first time. In this approach, the introduction of the gas-assisted localized liquid discharge apparatus provides an instantaneous gaseous environment for underwater LIBS measurement (that is, the transfer of sampling matrix is not needed from aqueous solution to dry state).

[Comparative Study on Laser Induced Breakdown Spectroscopy Based on Single Pulse and Re-Heating Orthogonal Dual Pulse].

In order to improve the detection sensitivity and spectral characteristic of laser-induced breakdown spectroscopy (LIBS), re-heating orthogonal dual-pulse configuration is adopted to analyze Fe, Pb, Ca and Mg contained in the sample and soil sample contained different concentrations of heavy mental Cr. Variation relationship between spectral intensity, signal-to-background(SBR) of four characteristic spectral lines FeⅠ：404.581 nm，PbⅠ：405.

[Rapid Quantitative Detection of Bacterial in Water Based on Multi-Wavelength Scattering Spectra].

The structures of bacterial cells are analyzed in this paper. The scattering components of individual cell were divided into two parts including external structure and internal structure. The interpretation model of bacteria about scattering light is established.

[Laser Induced Time-Resolved Fluorescence Spectroscopy Characteristics of Fluoranthene in Ethanol with Eanosecond Laser of 355 nm].

Polycyclic Aromatic Hydrocarbons (PAHs) have been widely investigated in environmental field, for most of them are mutagenic (carcinogenic, teratogenic, mutagenic). The influence of delay time and gate width on the time-resolved fluorescence spectroscopy of fluoranthene in ethanol was studied in this paper. Furthermore, laser induced time-resolved fluorescence spectroscopy of fluoranthene with different concentration were also researched.

[Quantitative Analysis of Cr in Soil with Laser Induced Breakdown Spectroscopy Combined With Multivariate Calibration].

Laser-induced breakdown spectroscopy (LIBS) was used to calibrate the concentration of Cr in soils combined with Support Vector Machine. The Nd:YAG pulse laser with the wavelength of 1 064 nm was used as the excitation source. The grating spectrometer and the charge couple device were used as spectral separation device and the spectral detection device.

[Effect of Methanol-Water Mixture on Three-Dimensional Fluorescence Spectra of Carbaryl].

Extensive use of pesticides has a significant impact on the environment. Carbaryl, whose residues stay in the surface water, is one of the most widely used broad spectrum insecticides in agriculture. It is important to understand carbaryl spectral characteristics and detection methods.

[Quantitative Analysis of Heavy Metals in Water with LIBS Based on Signal-to-Background Ratio].

There are many influence factors in the precision and accuracy of the quantitative analysis with LIBS technology. According to approximately the same characteristics trend of background spectrum and characteristic spectrum along with the change of temperature through in-depth analysis, signal-to-background ratio (S/B) measurement and regression analysis could compensate the spectral line intensity changes caused by system parameters such as laser power, spectral efficiency of receiving. Because the measurement dates were limited and nonlinear, we used support vector machine (SVM) for regression algorithm.

[Analysis of lead in unknown samples based on the standard addition method using laser induced breakdown spectroscopy].

The standard addition method with laser induced breakdown spectroscopy was used to analyze an unknown sample taken from a lead battery factory. the matrix influence on the results was effectively avoided when the external or internal standard method was used, and the pretreatment of samples was simple and quick. The Nd ' YAG pulse laser with wavelength 1 064 nm was used as the excitation source.

[Analysis of heavy metals distribution characteristics and pollution assessment in agricultural region soils of Huaihe basin].

By means of field sampling and laboratory analysis, the content distribution characteristics of Cd, Cr, Cu, Ni, Pb and Zn in agricultural region soils of Huaihe basin in Anhui province were analyzed. Assessment of heavy metal pollutions was conducted using enrichment factor, geoaccumulation index and potential ecological risk index. The results showed that the average mass fraction of Cd and Cu was 0.

[Research on parameter optimization of LIBS used for multi-element measurements in water].

The one of the advantages about Laser Induced Breakdown Spectroscopy (LIBS) is multielement detection at the same time. In order to obtain the optimum signal in the multi-element measurements of water with LIBS, the present paper firstly models the numerical relationship between the signal-to-background ratio of characteristic spectral lines and the delay time and gate width time with BP neural network, using DM design experiment data as the checking sample to ensure the generalization ability of the BP neural network model. Based on the above model, genetic algorithm is used to optimize measurement parameters and the fitness function phi is defined.

[The method of phytoplankton photosynthesis activity in-situ measurement based on light induced fluorescence].

According to the phytoplankton fluorescence induction characteristics under different light conditions, chlorophyll fluorescence as a probe for analysis of phytoplankton photosynthesis was studied. The present paper proposed a in-situ measurement method based on the chlorophyll fluorescence values Ft and Fm to get phytoplankton photosynthesis activity, Chlorella vulgaris, microcystis aeruginosa and Cyclotella meneghiniana Kiits were selected as experimental subjects, a comparison test was done between self-developed in-situ measurement system and Water PAM in lab, and the results showed that coefficients between the two methods were 0.9778, 0.

[Study on measurement of trace heavy metal Ni in water by laser induced breakdown spectroscopy technique].

The spectroscopy emission characteristics and the detection limit of trace heavy metal nickel in water was studied based on laser induced breakdown spectroscopy technique, with a 1,064 nm wavelength Nd : YAG laser as excitation source, and the echelle spectrometer and ICCD detector were used for spectral separation and high sensitive detection with high resolution and wide spectral range. A round flat solid state graphite as matrix was used for element enrichment for reducing water splashing, extending the plasma lifetime and improving the detection sensitivity, and the experimental sample was prepared by titrating a fixed volume of nickel nitrate solution of different concentrations on a fixed area of the graphite matrix. The results show that the better detection delay time is about 700 ns, the spectrum intensity raises with the concentration increase, a good linear relationship is presented at low concentration with a correlation coefficient 0.