Publications by authors named "Dan-Dan Huang"

Reactive nitrogen (Nr) emissions significantly affect air quality and the nitrogen cycle in ecosystems. Heavy-duty diesel vehicles (HDDVs), as major sources of these emissions, exhibit complex emission characteristics because of the combined effects of different driving conditions and aftertreatment technologies. This study first investigated the emission factors (EFs) of Nr species, including NO, NO, HONO, NO, and NH, from HDDVs under different emission standards (China IV/V/VI) and cheating strategies, with a particular focus on the impact of selective catalytic reduction (SCR) systems.

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  • The study focuses on the molecular characterization of organic aerosol (OA) to better understand its sources and atmospheric processes, particularly in Xi'an, Northwest China.
  • Using advanced techniques like gas chromatography-Orbitrap mass spectrometry (GC-Orbitrap MS), the study identified 335 organic compounds, surpassing the results from a traditional method (GC-qMS).
  • Seasonal changes in OA composition point to varying sources of organic materials, such as indoor emissions in winter and biogenic sources in warmer months, with analysis methods revealing important patterns in local and transport emissions.
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Most known chemiluminescence (CL) systems are flash-type that generate weak luminescence and decline quickly after dozens of seconds, while the glow-type CL systems have stable emission for an extended period to achieve accurate quantitation. In this work, a long-term CL system based on hydrazine-hydrate (NH·HO) modified carbon quantum dots (N-CQDs) as a luminescent probe, with KSO and HO as co-reactants, was proposed. The CL emission enhanced by HO increased 18-fold more than that of N-CQDs and KSO direct reaction, and decayed by 5% of the maximum intensity over 700 s.

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Secondary organic aerosol (SOA) formation from gasoline vehicles spanning a wide range of emission types was investigated using an oxidation flow reactor (OFR) by conducting chassis dynamometer tests. Aided by advanced mass spectrometric techniques, SOA precursors, including volatile organic compounds (VOCs) and intermediate/semivolatile organic compounds (I/SVOCs), were comprehensively characterized. The reconstructed SOA produced from the speciated VOCs and I/SVOCs can explain 69% of the SOA measured downstream of an OFR upon 0.

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Aromatic carbonyls have been mainly probed as photosensitizers for aqueous secondary organic aerosol (aqSOA) and light-absorbing organic aerosol (i.e., brown carbon or BrC) formation, but due to their organic nature, they can also undergo oxidation to form aqSOA and BrC.

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Purpose: The study comprehensively evaluated the prognostic roles of the platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), basophil-to-lymphocyte ratio (BLR), and eosinophil-to-lymphocyte ratio (ELR) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

Patients And Methods: Six hundred and nineteen patients with AECOPD and 300 healthy volunteers were retrospectively included into the study. The clinical characteristics of the patients with AECOPD and the complete blood counts (CBCs) of the healthy volunteers were collected.

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  • Inflammation is linked to depression, but how they connect isn’t fully understood; this study specifically investigates the role of circadian clock genes, particularly Bmal1, in this relationship.
  • The research utilized LPS-injected rats and BV2 cells to analyze the effects, revealing that LPS induced depression-like behavior and an inflammatory response in the rats, with various immune markers being affected.
  • Findings showed altered expression of neurotrophic factors and circadian genes in the brain, indicating that disruptions in circadian rhythms and inflammation processes could play a critical role in the development of depression.
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Background: Studies on antiretroviral therapy (ART) in children living with HIV (CLHIV) are limited due to the small population and low accession rate of ART.

Methods: All 0-14-year-old CLHIV admitted to the Ganzhou Center for Disease Control and Prevention from January 2006 to June 2023 were included retrospectively. The information of treatment regimens, disease progression, and laboratory tests of the patients under ART were used to explore the outcomes and impacts of long-term ART.

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Aqueous-phase reactions of α-dicarbonyls with amines or ammonium have been identified as important sources of secondary brown carbon (BrC). However, the kinetics of BrC formation and the effects of pH are still not very clear. In this study, the kinetics of BrC formation by aqueous reactions of α-dicarbonyls (glyoxal and methylglyoxal) with ammonium, amino acids, or alkylamines in bulk solution at different pH values are investigated.

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  • Two different isomeric forms of indium bromide crystals, α and β, were created by altering cooling conditions during their synthesis.
  • Structural differences reveal varied supramolecular interactions, supported by Hirshfeld surface analysis.
  • The α form exhibits a significantly higher photoluminescence quantum yield due to its compact structure and effective electron transfer processes, offering insights for future design of luminescent indium-based materials.*
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Aqueous-phase reactions of αdicarbonyls with ammonium or amines have been identified as important sources of secondary brown carbon (BrC). However, the identities of most chromophores in these reactions and the effects of pH remain largely unknown. In this study, the chemical structures, formation pathways, and optical properties of individual BrC chromophores formed through aqueous reactions of αdicarbonyls (glyoxal and methylglyoxal) with ammonium, amino acids, or methylamine at different pH's were characterized in detail by liquid chromatography-photodiode array-high resolution tandem mass spectrometry.

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Oxygenated organic molecules (OOMs) are critical intermediates linking volatile organic compound oxidation and secondary organic aerosol (SOA) formation. Yet, the understanding of OOM components, formation mechanism, and impacts are still limited, especially for urbanized regions with a cocktail of anthropogenic emissions. Herein, ambient measurements of OOMs were conducted at a regional background site in South China in 2018.

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Understanding the effects of different tillage practices on functional microbial abundance and composition in nitrogen (N), phosphorus (P) and sulfur (S) cycles are essential for the sustainable utilization of black soils. Based on an 8-year field experiment located in Changchun, Jilin Province, we analyzed the abundance and composition of N, P and S cycling microorganisms and their driving factors in different depths of black soil under no til-lage (NT) and conventional tillage (CT). Results showed that compared with CT, NT significantly increased soil water content (WC) and microbial biomass carbon (MBC) at soil depth of 0-20 cm.

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Oxidation of volatile organic compounds (VOCs) forms oxygenated organic molecules (OOMs), which contribute to secondary pollution. Herein, we present measurement results of OOMs using chemical ionization mass spectrometry with nitrate as the reagent ion in Shanghai. Compared to those in forests and laboratory studies, OOMs detected at this urban site were of relatively lower degree of oxygenation.

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Objective: To predict the risk factors for cardiovascular events within 5 years in patients with peritoneal dialysis-associated peritonitis and establish a nomogram for clinical prediction.

Methods: A prediction model was established by conducting an observational study in 150 patients with peritoneal dialysis-associated peritonitis obtained from the Information Database of AnHui Medical University Affiliated Hospital. The nomogram was constructed using the multivariate COX regression model.

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High particulate matter (PM) pollution episodes still occur occasionally in urban China, despite of improvements in recent years. Investigating the influencing factors of high-PM episodes is beneficial in the formulation of effective control measures. We herein present the effects of weather condition, emission source, and chemical conversion on the occurrence of high-PM episodes in urban Shanghai using multiple online measurements.

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Objective: To observe the clinical effect of moxibustion with on Alzheimer's disease (AD) rats, and evaluate its effect on β-amyloid (Aβ) transport and enzymatic degradation proteins, to explore its molecular mechanism for improving cognitive function.

Methods: Sixty SPF-grade male SD rats were randomly divided into a blank group (8 rats), a sham-operation group (8 rats) and a model establishment group (44 rats). The rats in the model establishment group were injected with Aβ- at bilateral ventricles to establish AD model.

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Hyperhomocysteinemia is an independent risk factor for atherosclerosis. It is known that macrophage autophagy plays a protective role in atherosclerosis and that hyperhomocysteinemia is strongly linked to autophagy. Therefore, it is of great significance to study the molecular mechanisms underlying the effect of homocysteine (Hcy) on macrophage autophagy.

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Red tilapia ( spp ) is one of the most popular fish in China due to its bright red appearance, fast growth rate, and strong adaptability. Understanding the sex determination mechanisms is of vital importance for the selection of all-male lines to increase aquacultural production of red tilapia. In this research, the genetic architecture for sex from four mapping populations ( =1 090) of red tilapia was analyzed by quantitative trait loci (QTL)-seq, linkage-based QTL mapping, and linkage disequilibrium (LD)-based genome-wide association studies.

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Background: Soil salinization extensively hampers the growth, yield, and quality of crops worldwide. The most effective strategies to counter this problem are a) development of crop cultivars with high salt tolerance and b) the plantation of salt-tolerant crops. Glycyrrhiza inflata, a traditional Chinese medicinal and primitive plant with salt tolerance and economic value, is among the most promising crops for improving saline-alkali wasteland.

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  • Nitrous acid (HONO) is crucial for understanding tropospheric chemistry and can form both directly and secondarily in the atmosphere, particularly through reactions involving organic compounds in aerosols.
  • The study examined how nitrite is produced from the photolysis of nitrate under various conditions, revealing that the presence of certain small organic molecules can impact nitrite production efficiency.
  • Findings suggest that brown carbon (BrC) enhances nitrite generation through a process where its excited state helps convert nitrate to nitrite, offering insights into why HONO levels may be lower than expected in urban settings.
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Hydrogen sulfide(HS) is one of the most common gas products from modern industrial processes. It is highly toxic, corrosive, and polluting, and poses harm to both the natural environment and human health if it is not properly removed. Biochar has been widely applied for the treatment of environmental pollution due to its excellent adsorption ability, low cost, and wide choice of source materials.

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Cooking organic aerosol (COA) is an important source of particulate pollutants in urbanized regions. Yet, the diversity and complexity of COA components make direct identification and quantification of COA difficult. In this study, we conducted collocated OA measurements with an aerosol mass spectrometer (AMS) and a thermal desorption aerosol gas chromatography-mass spectrometer (TAG) in Shanghai.

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Background: Drug resistance mutation (DRM)-associated virological failure has become a critical issue for ART and the elimination of HIV.

Objectives: To investigate the distribution characteristics of DRMs of HIV CRF01_AE, CRF07_BC and CRF08_BC, the predominant subtypes in China.

Methods: Patients receiving ART up to 31 August 2020 in Ganzhou in China were recruited.

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