Raman-Polarization-Fluorescence Spectroscopic Lidar for Real-Time Detection of Humic-like Substance Profiles.

Humic-like substances (HULIS) widely exist in the atmosphere and may strongly affect human health, environment, and climate. However, there are still no accurate methods for detecting the vertical distribution of HULIS. Here, a Raman-Polarization-Fluorescence Spectroscopic Lidar (RPFSL) was developed to simultaneously measure 64-channel broad fluorescence spectra (370-710 nm) of atmospheric aerosols at an excitation wavelength of 355 nm.

Long-term trend of dust event duration over Northwest China.

Dust events in Northwest China have become more variable under regional climate change. Prior research has largely overlooked the spatial-temporal distribution of dust event duration (DED) and its long-term trend. This study systematically analyzed the spatial and temporal variations of DED in Northwest China and explored their associated factors using satellite-derived air quality datasets during 2000-2021.

Impact of aerosol-boundary layer interactions on PM pollution during cold air pool events in a semi-arid urban basin.

Global emission reductions still must address winter fine particulate matter (PM) pollution in urban basins with enclosed terrains and frequent cold air pool (CAP) events when the temperatures within the basin are colder than above it. The effects of urban basin aerosol-boundary layer interactions on PM pollution during CAP events remain unclear. Intensive boundary layer observations in January 2021 and numerical models were used to investigate this issue in the semi-arid urban Lanzhou Basin of China.

Comparison of Surgical and Colonoscopy Tissue to Establish Colorectal Patient-derived Organoids.

Background: Patient-derived organoids (PDOs) are ex vivo models that retain the functions and characteristics of individualized source tissues, including a simulated tumor microenvironment. However, the potential impact of undiscovered differences between tissue sources on PDO growth and progression remains unclear.

Objective: This study aimed to compare the growth and condition of PDO models originating from surgical resection and colonoscopy and to provide practical insights for PDO studies.

Enhancement of atmospheric oxidation capacity induced co-pollution of the O and PM in Lanzhou, northwest China.

In recent years, the co-pollution of surface ozone (O) and fine particulate matter (PM) has emerged as a critical concern within specific regions of China's atmospheric environment. This study employed a comprehensive approach by integrating statistical analysis with the interpretable ensemble machine learning model. Delving deeply into the intricate mechanisms behind O and PM co-pollution in Lanzhou city from 2019 to 2022, the research synthesized and analyzed an array of data sources, including ground observations, a multi-parameter lidar system, and meteorological data.

Significant roles of aged dust aerosols on rapid nitrate formation under dry conditions in a semi-arid city.

Mineral dust can accelerate secondary aerosol formation under humid conditions. However, it is unclear whether it can promote secondary aerosol formation under dry conditions. To investigate this issue, two years of comprehensive observations was conducted at a semi-arid site, near the dust source regions.

Identification of fluorescent aerosol observed by a spectroscopic lidar over northwest China.

Bioaerosols play a significant role in climate change and variation of ecological environment. To investigate characterization of atmospheric bioaerosols, we conducted lidar measurement for observing bioaerosols close to dust sources over northwest China in April, 2014. The developed lidar system can not only allowed us to measure the 32-channel fluorescent spectrum between 343 nm to 526 nm with a spectral resolution of 5.

Method for retrieving range-resolved aerosol microphysical properties from polarization lidar measurements.

Aerosol microphysical properties, such as volume concentration (VC) and effective radius (ER), are of great importance to evaluate their radiative forcing and impacts on climate change. However, range-resolved aerosol VC and ER still cannot be obtained by remote sensing currently except for the column-integrated one from sun-photometer observation. In this study, a retrieval method of range-resolved aerosol VC and ER is firstly proposed based on the partial least squares regression (PLSR) and deep neural networks (DNN), combining polarization lidar and collocated AERONET (AErosol RObotic NETwork) sun-photometer observations.

"Urban Respiration" Revealed by Atmospheric O Measurements in an Industrial Metropolis.

Urban regions, which "inhale" O from the air and "exhale" CO and atmospheric pollutants, including harmful gases and fine particles, are the largest sinks of atmospheric O, yet long-term O measurements in urban regions are currently lacking. In this study, we report continuous measurements of atmospheric O in downtown Lanzhou, an industrial metropolis in northwestern China. We found declines in atmospheric O associated with deteriorated air quality and robust anticorrelations between O and gaseous oxides.

Predicting ozone formation in petrochemical industrialized Lanzhou city by interpretable ensemble machine learning.

Ground-level ozone (O) formation depends on meteorology, precursor emissions, and atmospheric chemistry. Understanding the key drivers behind the O formation and developing an accurate and efficient method for timely assessing the O-VOCs-NOx relationships applicable in different O pollution events are essential. Here, we developed a novel machine learning ensemble model coupled with a Shapley additive explanation algorithm to predict the O formation regime and derive O formation sensitivity curves.

Potential influence of fine aerosol chemistry on the optical properties in a semi-arid region.

The current understanding regarding the potential influence of aerosol chemistry on the optical properties does not satisfy accurate evaluation of aerosol radiative effects and precise determination of aerosol sources. We conducted a comprehensive study of the potential influence of aerosol chemistry on the optical properties in a semi-arid region based on various observations. Organic matter was the main contributor to the scattering coefficients followed by secondary inorganic aerosols in all seasons.

Changes in physical and chemical properties of urban atmospheric aerosols and ozone during the COVID-19 lockdown in a semi-arid region.

The synergistic response of urban atmospheric aerosols and ozone (O) to reduction of anthropogenic emissions is complicated and still needs further study. Thus, the changes in physical and chemical properties of urban atmospheric aerosols and O during the Coronavirus Disease 2019 (COVID-19) lockdown were investigated at three urban sites and one rural site in Lanzhou with semi-arid climate. Fine particulate matter (PM) decreased at four sites by ∼ 20% while O increased by >100% at two urban sites during the COVID-19 lockdown.

Classification of atmospheric aerosols and clouds by use of dual-polarization lidar measurements.

Accurate identification of aerosols and cloud from remote sensing observations is of importance for quantitatively evaluating their radiative forcing and related impacts. Even though polarization lidar has exhibited a unique advantage of classifying atmospheric aerosols and clouds over the past several decades, polarization measurements are often achieved at one wavelength (UV or VIS) using laser remote sensing. To better identify the types of aerosols and clouds, we developed a ground-based dual-polarization lidar system that can simultaneously detect polarization measurements at wavelengths of 355 nm and 532 nm.

High contribution of vehicle emissions to fine particulate pollutions in Lanzhou, Northwest China based on high-resolution online data source appointment.

The quantitative estimation of urban particulate matter (PM) sources is essential but limited because of various reasons. The hourly online data of PM, organic carbon (OC), elemental carbon (EC), water-soluble ions, and elements from December 2019 to November 2020 was used to conduct PM source appointment, with an emphasis on the contribution of vehicle emissions to fine PM pollution in downtown Lanzhou, Northwest China. Vehicle emissions, secondary formation, mineral dust, and coal combustion were found to be the major PM sources using the positive matrix factorization model.

Source apportionment of atmospheric particle number concentrations with wide size range by nonnegative matrix factorization (NMF).

Quantifying the sources of atmospheric particles is essential to air quality control but remains challenging, especially for the source apportionment of particles based on number concentration with wide size range. Here, particle number concentrations (PNC) with size range 19-20,000 nm involving four modes Nucleation, Aitken, Accumulation, and Coarse are used to do source apportionment of PNC at the Guangdong Atmospheric Supersite (Heshan) during July-October 2015 by nonnegative matrix factorization (NMF) with 6 factors. For July 2015, separated source apportionments for three different size ranges from collocated instruments nano scanning mobility particle sizer (NSMPS), SMPS, and aerodynamic particle sizer (APS) and for two different size ranges (below and above 100 nm) show similar quantitative source information with that for the one whole size range.

Water-soluble brown carbon in atmospheric aerosols along the transport pathway of Asian dust: Optical properties, chemical compositions, and potential sources.

As an important type of light-absorbing aerosol, brown carbon (BrC) has the potential to affect the atmospheric photochemistry and Earth's energy budget. A comprehensive field campaign was carried out along the transport pathway of Asian dust during the spring of 2016, including a desert site (Erenhot), a rural site (Zhangbei), and an urban site (Jinan), in northern China. Optical properties, bulk chemical compositions, and potential sources of water-soluble brown carbon (WS-BrC) were investigated in atmospheric total suspended particulate (TSP) samples.

Investigation of aerosol absorption with dual-polarization lidar observations.

Polarization lidar has been widely used in recent decades to observe the vertical structures of aerosols and clouds in the atmosphere. We developed a dual-polarization lidar system that can detect polarization measurements simultaneously at 355 nm and 532 nm. Dust events and haze episodes over northern China in 2014 were observed by the developed lidar.

Automated detection of cloud and aerosol features with SACOL micro-pulse lidar in northwest China.

The detection of cloud and aerosols using a modified retrieval algorithm solely for a ground-based micropulse lidar (MPL) is presented, based on one-year data at the Semi-Arid Climate Observatory and Laboratory (SACOL) site (35.57°N, 104.08°E, 1965.

First Chemical Characterization of Refractory Black Carbon Aerosols and Associated Coatings over the Tibetan Plateau (4730 m a.s.l).

Refractory black carbon (rBC) aerosol is an important climate forcer, and its impacts are greatly influenced by the species associated with rBC cores. However, relevant knowledge is particularly lacking at the Tibetan Plateau (TP). Here we report, for the first time, highly time-resolved measurement results of rBC and its coating species in central TP (4730 m a.

Light absorption by water-soluble organic carbon in atmospheric fine particles in the central Tibetan Plateau.

Brown carbon (BrC) has recently received much attention because of its light absorption features. The chemical compositions, optical properties, and sources of fine aerosol at a high-elevation mountain observatory (4730 m a.s.

Variants and haplotypes in Flap endonuclease 1 and risk of gallbladder cancer and gallstones: a population-based study in China.

The role of FEN1 genetic variants on gallstone and gallbladder cancer susceptibility is unknown. FEN1 SNPs were genotyped using the polymerase chain reaction-restriction fragment length polymorphism method in blood samples from 341 gallbladder cancer patients and 339 healthy controls. The distribution of FEN1-69G > A genotypes among controls (AA, 20.

Upregulated plasma and urinary levels of nucleosides as biological markers in the diagnosis of primary gallbladder cancer.

We first detected aberrant nucleoside levels in the plasma, urine, bile, and tissues from cases and controls to explore them as biomarkers in the diagnosis of gallbladder cancer. Reversed-phase high-performance liquid chromatography was used to assess the levels of ten nucleosides in these samples from gallbladder cancer patients, gallstone patients, and healthy controls. Plasma and urine samples were collected from patients with gallbladder cancer (n = 202), patients with gallstones (n = 203), and healthy controls (n = 205); bile and tissue samples were collected from 91 gallbladder cancer patients, 93 gallstone patients; and 90 were donated after cardiac death.

Ala499Val (C>T) and Lys939Gln (A>C) polymorphisms of the XPC gene: their correlation with the risk of primary gallbladder adenocarcinoma--a case-control study in China.

Genetic variations in the gene XPC may be associated with increased risk for gallbladder cancer (GBC). In this study, we detected two non-synonymous polymorphisms in XPC (Ala499Val and Lys939Gln) in 334 cases of GBC and 329 subjects of hospital-based age- and sex frequency-matched controls in China using a polymerase chain reaction-restriction fragment length polymorphism assay. Allelic association analysis for the two single-nucleotide polymorphisms (SNPs) showed that the risk allele T of Ala499Val was significantly associated with GBC [odds ratio (OR)=1.

Multivariate statistical analysis of clinicopathologic factors influencing survival of patients with bile duct carcinoma.

Aim: To evaluate the influence of various clinicopathologic factors on survival of patients with bile duct carcinoma after curative resection.

Methods: A retrospective analysis was made for 86 cases of bile duct carcinoma treated from January 1981 to September 1995. Fifteen clinicopathologic factors possibly influencing survival were selected.