Additional file 1 of Engineering defected 2D Pd/H-TiO2 nanosonosensitizers for hypoxia alleviation and enhanced sono-chemodynamic cancer nanotherapy

Additional file 1. Additional information includes part of materials and methods, as well as additional figures

DataSheet1_Description of the Molecular and Phenotypic Spectrum of Lesch-Nyhan Disease in Eight Chinese Patients.docx

Background: Lesch-Nyhan disease (LND) is a rare disorder involving pathogenic variants in the HPRT1 gene encoding the enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRT) that result in hyperuricemia, intellectual disability, dystonic movement disorder, and compulsive self-mutilation. The purpose of the present study was to characterize the genetic basis of LND and describe its phenotypic heterogeneity by identifying the variation in the HPRT1 gene in a cohort of Chinese LND patients.Results: The median age at diagnosis was 31 mo (interquartile range (IQR): 7–76 mo), and the initial manifestations were mainly head control weakness and motor development delay. The median age of self-mutilation behavior onset was 19 mo (IQR: 17–24 mo), and all patients were required to travel in a wheelchair and fall into the predicament of compulsive self-harm behavior. There were two patients whose blood uric acid levels were normal for their high urinary acid excretion fraction without taking uric acid-lowering drugs. Seven different pathogenic variants of the HPRT1 gene were identified among eight independent pedigrees, including four novel mutations [c.299 (exon 3) T > A; loss (exon: 6) 84 bp; c.277_281delATTGC; c.468_470delGAT]. The pathogenic variant sites were mainly concentrated in exon 3, and truncating mutations (including frameshift mutations and nonsense mutations) were the most common genetic variant types (5/7, 71.4%).Conclusion: The present study described the phenotypic and molecular spectrum of LND in eight Chinese families, including four novel mutations, which expands our understanding of LND.</p

Solubility of Xylene Isomers in Seven Deep Eutectic Solvents

Emissions of volatile organic compounds (VOCs) have a substantial impact on the environment, and absorption methods are an important means of dealing with VOCs. In order to screen potential deep eutectic solvents (DESs) as liquid absorbers for capturing xylenes, seven DESs were prepared and were verified by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. The melting points of all DESs were well below the melting points of their raw materials, and the water content of all the DESs was less than 0.05 wt %. The viscosities of the seven DESs decreased with increasing temperature. The solubility of o-, m-, and p-xylene in the DESs was determined by the cloud point in the range of 303.15–353.15 K. The tetrabutylammonium bromide-based DESs had the greatest potential to dissolve xylene. Tetrabutylammonium bromide:triethylene glycol (1:4) exhibited the highest solubility for o-, m-, and p-xylene, with the mole fraction solubilities of 0.4075, 0.3754, and 0.3820, respectively (each at 353.15 K). The solubility magnitudes of the three isomers exhibited an overall trend of o-xylene > p-xylene ∼ m-xylene. The experimental solubility data were fitted with the dual-parameter equation and the Apelblat equation; the latter was a better fit

Contribution of Atmospheric Oxygenated Organic Compounds to Particle Growth in an Urban Environment

Gas-phase oxygenated organic molecules (OOMs) can contribute substantially to the growth of newly formed particles. However, the characteristics of OOMs and their contributions to particle growth rate are not well understood in urban areas, which have complex anthropogenic emissions and atmospheric conditions. We performed long-term measurement of gas-phase OOMs in urban Beijing during 2018–2019 using nitrate-based chemical ionization mass spectrometry. OOM concentrations showed clear seasonal variations, with the highest in the summer and the lowest in the winter. Correspondingly, calculated particle growth rates due to OOM condensation were highest in summer, followed by spring, autumn, and winter. One prominent feature of OOMs in this urban environment was a high fraction (∼75%) of nitrogen-containing OOMs. These nitrogen-containing OOMs contributed only 50–60% of the total growth rate led by OOM condensation, owing to their slightly higher volatility than non-nitrate OOMs. By comparing the calculated condensation growth rates and the observed particle growth rates, we showed that sulfuric acid and its clusters are the main contributors to the growth of sub-3 nm particles, with OOMs significantly promoting the growth of 3–25 nm particles. In wintertime Beijing, however, there are missing contributors to the growth of particles above 3 nm, which remain to be further investigated

Enigma of Urban Gaseous Oxygenated Organic Molecules: Precursor Type, Role of NO_<i>x</i>, and Degree of Oxygenation

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. This was attributed to the high NOx concentrations (∼44 ppb), which overall showed a suppression on the propagation reactions. As another result, a large fraction of nitrogenous OOMs (75%) was observed, and this fraction further increased to 84% under a high NO/VOC ratio. By applying a novel framework on OOM categorization and supported by VOC measurements, 50 and 32% OOMs were attributed to aromatic and aliphatic precursors, respectively. Furthermore, aromatic OOMs are more oxygenated (effective oxygen number, nOeff = 4–6) than aliphatic ones (nOeff = 3–4), which can be partly explained by the difference in initiation mechanisms and points to possible discrimination in termination reactions. This study highlights the roles of NOx in OOM formation in urban areas, as well as the formation of nitrogenous products that might show discrimination between aromatic and aliphatic VOCs

Underestimated Contribution of Heavy Aromatics to Secondary Organic Aerosol Revealed by Comparative Assessments Using New and Traditional Methods

Oxygenated organic molecules (OOMs) from oxidation of volatile organic compounds (VOCs) are important contributors to secondary organic aerosol (SOA) formation. Recent field studies showed that anthropogenic precursors significantly contributed to OOMs and subsequent SOA formation in urban areas. We conducted collocated OOM measurements with nitrate-ion chemical ionization mass spectrometry and SOA molecular tracer measurements with thermal desorption aerosol gas chromatography–mass spectrometry in Shanghai. Using the newly developed OOM-based method, we found that OOMs derived from aromatic VOCs (aromatic OOMs) dominated the local SOA production with a contribution of 52%. The traditional SOA tracer-based method estimated a consistent fraction of 49% from monoaromatics and polyaromatics (e.g., naphthalene and methylnaphthalene). We further categorized the aromatic OOMs into heavy (carbon number: nC > 9) and light (nC = 6–9) ones primarily based on the ring number. Surprisingly, the contribution of heavy aromatic OOMs to SOA formation (25%) was more than twice of the naphthalene-derived SOA from the tracer-based method (10%). The gap could be explained by the fact that the OOM-based method also counted the contributions from other polyaromatic VOCs that are beyond methyl-/naphthalene. The high degrees of oxygenation caused by multistep oxidation and the higher carbon number (nC > 9) in heavy aromatic OOMs lead to their lower volatility and higher contributions to SOA. Our study provides previously unavailable linkage between the aromatic SOA with its precursors via simultaneous measurements of OOMs and molecular tracers, revealing the overlooked contribution from heavy aromatic VOCs to SOA formation

Molecular Characterization of Oxygenated Organic Molecules and Their Dominating Roles in Particle Growth in Hong Kong

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. The molecular characteristics of OOMs revealed dominant nitrogen-containing products, and the influences of different factors on OOM composition and oxidation state were elucidated. Positive matrix factorization analysis resolved the complex OOM species to factors featured with fingerprint species from different oxidation pathways. A new method was developed to identify the key functional groups of OOMs, which successfully classified the majority species into carbonyls (8%), hydroperoxides (7%), nitrates (17%), peroxyl nitrates (10%), dinitrates (13%), aromatic ring-retaining species (6%), and terpenes (7%). The volatility estimation of OOMs was improved based on their identified functional groups and was used to simulate the aerosol growth process contributed by the condensation of those low-volatile OOMs. The results demonstrate the predominant role of OOMs in contributing sub-100 nm particle growth and SOA formation and highlight the importance of dinitrates and anthropogenic products from multistep oxidation

Insufficient Condensable Organic Vapors Lead to Slow Growth of New Particles in an Urban Environment

Atmospheric new particle formation significantly affects global climate and air quality after newly formed particles grow above ∼50 nm. In polluted urban atmospheres with 1–3 orders of magnitude higher new particle formation rates than those in clean atmospheres, particle growth rates are comparable or even lower for reasons that were previously unclear. Here, we address the slow growth in urban Beijing with advanced measurements of the size-resolved molecular composition of nanoparticles using the thermal desorption chemical ionization mass spectrometer and the gas precursors using the nitrate CI-APi-ToF. A particle growth model combining condensational growth and particle-phase acid–base chemistry was developed to explore the growth mechanisms. The composition of 8–40 nm particles during new particle formation events in urban Beijing is dominated by organics (∼80%) and sulfate (∼13%), and the remainder is from base compounds, nitrate, and chloride. With the increase in particle sizes, the fraction of sulfate decreases, while that of the slow-desorbed organics, organic acids, and nitrate increases. The simulated size-resolved composition and growth rates are consistent with the measured results in most cases, and they both indicate that the condensational growth of organic vapors and H2SO4 is the major growth pathway and the particle-phase acid–base reactions play a minor role. In comparison to the high concentrations of gaseous sulfuric acid and amines that cause high formation rates, the concentration of condensable organic vapors is comparably lower under the high NOx levels, while those of the relatively high-volatility nitrogen-containing oxidation products are higher. The insufficient condensable organic vapors lead to slow growth, which further causes low survival of the newly formed particles in urban environments. Thus, the low growth rates, to some extent, counteract the impact of the high formation rates on air quality and global climate in urban environments

Modeling the Formation of Organic Compounds across Full Volatility Ranges and Their Contribution to Nanoparticle Growth in a Polluted Atmosphere

Nanoparticle growth influences atmospheric particles’ climatic effects, and it is largely driven by low-volatility organic vapors. However, the magnitude and mechanism of organics’ contribution to nanoparticle growth in polluted environments remain unclear because current observations and models cannot capture organics across full volatility ranges or track their formation chemistry. Here, we develop a mechanistic model that characterizes the full volatility spectrum of organic vapors and their contributions to nanoparticle growth by coupling advanced organic oxidation modeling and kinetic gas-particle partitioning. The model is applied to Nanjing, a typical polluted city, and it effectively captures the volatility distribution of low-volatility organics (with saturation vapor concentrations 3), thus accurately reproducing growth rates (GRs), with a 4.91% normalized mean bias. Simulations indicate that as particles grow from 4 to 40 nm, the relative fractions of GRs attributable to organics increase from 59 to 86%, with the remaining contribution from H2SO4 and its clusters. Aromatics contribute much to condensable organic vapors (∼37%), especially low-volatility vapors (∼61%), thus contributing the most to GRs (32–46%) as 4–40 nm particles grow. Alkanes also contribute 19–35% of GRs, while biogenic volatile organic compounds contribute minimally (<13%). Our model helps assess the climatic impacts of particles and predict future changes