High-throughput semi-automated emulsive liquid-liquid microextraction for detecting SDHI fungicides in water, juice, and alcoholic beverage samples via UHPLC-MS/MS

Herein, a High-Throughput Semi-automated Emulsive Liquid-Liquid Microextraction (HTSA-ELLME) method was developed to detect Succinate Dehydrogenase Inhibitor (SDHI) fungicides in food samples via UHPLC-MS/MS. The Oil-in-Water (O/W) emulsion comprising a hydrophobic extractant and water was dilutable with the aqueous sample solution. Upon injecting the primary emulsion into the sample solution, a secondary O/W emulsion was formed, allowing SDHI fungicides to be extracted. Subsequently, a NaCl-saturated solution was injected in the secondary O/W emulsion as a demulsifier to rapidly separate the extractant, eliminating the need for centrifugation. A 12-channel electronic micropipette was used to achieve a high-throughput semi-automation of the novel sample pretreatment. The linear range was 0.003-0.3 μg L-1 with R2 > 0.998. The limit of detection was 0.001 μg L-1. The HTSA-ELLME method successfully detected SDHI fungicides in water, juice, and alcoholic beverage samples, with recoveries and relative standard deviations of 82.6-106.9% and 0.8-5.8%, respectively. Unlike previously reported liquid-liquid microextraction approaches, the HTSA-ELLME method is the first to be both high-throughput and semi-automated and may aid in designing pesticide pretreatment processes in food samples.

Anthropogenic forcing has increased the risk of longer-traveling and slower-moving large contiguous heatwaves

Heatwaves are consecutive hot days with devastating impacts on human health and the environment. These events may evolve across both space and time, characterizing a spatiotemporally contiguous propagation pattern that has not been fully understood. Here, we track the spatiotemporally contiguous heatwaves in both reanalysis datasets and model simulations and examine their moving patterns (i.e., moving distance, speed, and direction) in different continents and periods. Substantial changes in contiguous heatwaves have been identified from 1979 to 2020, with longer persistence, longer traveling distance, and slower propagation. These changes have been amplified since 1997, probably due to the weakening of eddy kinetic energy, zonal wind, and anthropogenic forcing. The results suggest that longer-lived, longer-traveling, and slower-moving contiguous heatwaves will cause more devastating impacts on human health and the environment in the future if greenhouse gas emissions keep rising and no effective measures are taken immediately. Our findings provide important implications for the adaption and mitigation of globally connected extreme heatwaves.

Evaluation of three-dimensional reconstructed palatal morphology in skeletal class III subjects with different vertical patterns using cone beam computed tomography

BACKGROUND

This study aims to evaluate the difference of three-dimensional (3D) reconstructed palatal morphology between subjects with skeletal Class III and skeletal Class I in different vertical patterns using cone beam computed tomography (CBCT).

METHODS

In this study, 89 subjects with skeletal Class III (49 females, 40 males; 25.45 ± 3.81 years) and 85 subjects with skeletal Class I (45 females, 40 males; 23.95 ± 4.45 years) were collected retrospectively and divided into hyperdivergent, normodivergent and hypodivergent groups. Dolphin software was used to reorient the CBCT images of these subjects. After segmenting 3D object of maxilla from the 3D skull by ProPlan software, Geomagic Studio was used to reconstruct 3D palatal morphology and establish an average 3D palatal morphology for each group. The differences of 3D palatal morphology between different groups were compared by deviation patterns on 3D colored map analysis.

RESULTS

3D colored map analysis showed the posterior part of male's palate was higher and wider than that of female's palate in skeletal Class III subjects. In skeletal Class III subjects, males with hyperdivergent pattern had a higher and narrower palate compared with hypodivergent subjects, while females with hyperdivergent had a higher but not obviously narrower palate compared with hypodivergent subjects. In the similar vertical patterns, skeletal Class III subjects had a flatter but not narrower palate compared with skeletal Class I subjects, along with a smaller palate volume.

CONCLUSIONS

This method allows more intuitive between-group comparisons of the differences of 3D palatal morphology. In skeletal Class III subjects, as the vertical dimension increased, the palate tends to be higher and narrower. Therefore, the influence of vertical patterns on the palatal morphology should be fully considered in the orthodontic and orthognathic treatment of skeletal Class III subjects.

Polyphasic Characterization and Genomic Insights into an Aerobic Denitrifying Bacterium, Shewanella zhuhaiensis sp. nov., Isolated from a Tidal Flat Sediment

A new, facultatively anaerobic, light-yellow, and rod-shaped bacterium designated as 3B26T isolated from Qi'ao Island's tidal flat sediment was identified. Strain 3B26T can hydrolyze gelatin, aesculin, and skim milk. The major cellular fatty acids were identified as iso-C15:0, referred to as summed feature 3, and C16:0; the polar lipids consisted of phosphatidylethanolamine, phosphatidylglycerol, and phospholipid; and the quinones contained Q-7, Q-8, MK-7, and MMK7. The genomic size of strain 3B26T was 4,682,650 bp, and its genomic DNA G + C content was 54.8%. While a 16S rRNA gene-based phylogenetic analysis confirmed that strain 3B26T belongs to the genus Shewanella, both phylogenomic inference and genomic comparison revealed that strain 3B26T is distinguishable from its relatives, and digital DNA-DNA hybridization (dDDH) values of 24.4-62.6% and average nucleotide identities (ANIs) of 83.5-95.6% between them were below the 70% dDDH and 96% ANI thresholds for bacterial species delineation. Genomic functional analysis demonstrated that strain 3B26T possesses complete gene clusters of eicosapentaenoic acid biosynthesis and denitrification. Based on the evidence above, strain 3B26T is considered to represent a novel species of the genus Shewanella, and the name Shewanella zhuhaiensis sp. nov. (type strain 3B26T = GDMCC 1.2057T = KCTC 82339T) is proposed.

The effect of self-directed online metacognitive listening practice on Chinese EFL learners' listening ability, metacognition, and self-efficacy

Research into metacognitive listening instruction under the Metacognitive Pedagogical Cycle (MPC) has been growing in recent decades, but its effects on L2 listening comprehension, metacognitive awareness, and self-efficacy remain inconclusive. In this mixed-method study, we developed a self-directed online listening practice based on the MPC and investigated its effects on 89 Chinese intermediate EFL learners over 14 weeks. Learners were assigned to either an experimental group, which used the online metacognitive listening practice, or a control group, which used the traditional listening practice without stressing metacognitive awareness. Multiple data sources (listening tests, questionnaires, reflective notes, and interviews) were used to assess learners' listening comprehension, metacognitive awareness, and listening self-efficacy. Results showed that online metacognitive listening practice significantly improved the learners' listening comprehension, but there was little evidence that it increased metacognitive awareness or listening self-efficacy. This study suggests that deploying online listening practice under MPC is a more effective way to improve L2 learners' listening comprehension than traditional listening practice. However, the task-setting of MPC and the task-dependence of self-efficacy may constrain the development of some factors of metacognitive awareness and self-efficacy.

Enhanced adsorption of phenol from aqueous solution by KOH combined Fe-Zn bimetallic oxide co-pyrolysis biochar: Fabrication, performance, and mechanism

In this study, impregnation combined with KOH activation with different mixing methods was used to prepare magnetic biochar. The effects of synthetic method on biochar physicochemical properties and adsorption performance were explored. The results showed that treatment of a Fe-Zn oxide with KOH activation provided excellent adsorption properties with adsorption capacity of 458.90 mg/g due to well-developed microporous structure and rich-in O-containing functional groups as well as exposed oxidizing functional groups (Fe2O3 and FeOOH). Langmuir-Freundlich and pseudo-second-order models accurately fit phenol adsorption. Neutral conditions (pH = 6) and lower ionic strengths were beneficial to phenol removal. Additionally, the predominant adsorption processes were physisorption and chemisorption. Correlation analyses and characterization data confirmed that pore filling, π-π interactions and surface complexation were the dominant driving forces for phenol adsorption. This research provides an environmentally friendly method for utilizing agricultural wastes for the removal of a variety of pollutions from aquatic environment.

Terminal Residue and Dietary Risk Assessment of Atrazine and Isoxaflutole in Corn Using High-Performance Liquid Chromatography-Tandem Mass Spectrometry

Isoxaflutole and atrazine are representative pesticides for weed control in corn fields. Formulations containing these two pesticides have been registered in China, and their residues may threaten food safety and human health. In this study, a method for simultaneous determination of isoxaflutole, atrazine, and their metabolites in fresh corn, corn kernels, and corn straw was established based on modified QuEChERS pre-treatment and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The linearity of seven compounds was good (R2 ≥ 0.9912), and the matrix effect was 48.5-77.1%. At four spiked levels of 0.01, 0.02, 0.05, and 0.5 mg kg-1, all compounds' average recovery was 76% to 116%, with relative standard deviation (RSD) less than 18.9%. Field experiments were conducted in Liaoning, Heilongjiang, Inner Mongolia, Shanxi, Beijing, and Yunnan provinces to study the terminal residues. The terminal residues of all compounds were below the LOQ (0.01 mg kg-1) in fresh corn and corn kernels, and atrazine residues in corn straw ranged from <0.05 mg kg-1 to 0.17 mg kg-1. Finally, a dietary risk assessment was conducted based on residues from field trials, food consumption, and acceptable daily intake (ADI). For all populations, the chronic dietary risk probability (RQc) of atrazine was between 0.0185% and 0.0739%, while that of isoxaflutole was 0.0074-0.0296%, much lower than 100%. The results may provide scientific guidance for using isoxaflutole and atrazine in corn field ecosystems.

Gimibacter soli gen. nov. sp. nov., isolated from mangrove soil and insight into its ecological distribution and metabolic potential

A Gram-stain-negative, facultatively anaerobic, motile and rod-shaped bacterium, designated as 6D33^T, was isolated from mangrove soil. Growth was found to occur at 15-32 °C (optimum, 28 °C), at pH 6-9 (optimum, pH 7) and in 0-3 % NaCl (optimum, 1 %, w/v). The results of 16S rRNA gene-based analysis showed that strain 6D33^T belonged to the family Temperatibacteraceae, sharing 93.1-94.4 % identity with its close neighbours within the genus Kordiimonas. The phylogenomic results indicated that strain 6D33^T formed an independent branch distinct from type strains of the genus Kordiimonas. The overall genome relatedness indices of digital DNA-DNA hybridization, average nucleotide identity and amino acid identity values showed that strain 6D33^T represents a novel species of a novel genus. The results of chemotaxonomic characterization indicated that the major cellular fatty acids of strain 6D33^T were summed feature 9 (C_16 : 0 10-methyl and/or iso-C_17 : 1  ω9c), summed feature 3 (C_16 : 1  ω6c and/or C_16 : 1  ω7c) and iso-C_15 : 0; the polar lipids comprised diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, an unidentified aminolipid and three unidentified lipids; the only respiratory quinone was ubiquinone-10. The genomic size and DNA G+C contents were 3.59 Mbp and 60.84 mol%, respectively. The 16S rRNA gene sequence reads abundance profiles revealed that the rare taxon is prevalent in marine environments, especially in sediments. Genome-scale metabolic reconstruction of strain 6D33^T revealed a heterotrophic lifestyle and many pathways responsible for the degradation of aromatic compounds, suggesting application potential in aromatic hydrocarbon removal. Based on its genotypic and phenotypic characteristics, strain 6D33^T is concluded to represent a novel species of the novel genus in the family Temperatibacteraceae, for which the name Gimibacter soli gen. nov. sp. nov. is proposed. The type strain of the type species is 6D33^T (=GDMCC 1.1959^T=KCTC 82335^T).

Bamboo-derived nitrogen-doping magnetic porous hydrochar coactivated by K2FeO4 and CaCO3 for phenol removal: Governing factors and mechanisms

In this study, a novel nitrogen-doped magnetic Fe-Ca codoped biochar for phenol removal was successfully fabricated via a hydrothermal and coactivation pyrolysis method. A series of adsorption process parameters (K₂FeO₄ to CaCO₃ ratio, initial phenol concentration, pH value, adsorption time, adsorbent dosage and ion strength) and adsorption models (kinetic models, isotherms and thermodynamic models) were determined using batch experiments and various analysis techniques (XRD, BET, SEM-EDX, Raman spectroscopy, VSM, FTIR and XPS) to investigate the adsorption mechanism and metal-nitrogen-carbon interaction. The biochar with a ratio of Biochar: K₂FeO₄: CaCO₃ = 3:1:1 exhibited superior properties for adsorption of phenol and had a maximum adsorption capacity of 211.73 mg/g at 298 K, C₀ = 200 mg/L, pH = 6.0 and t = 480 min. These excellent adsorption properties were due to superior physicomechanical properties (a large specific surface area (610.53 m²/g) and pore volume (0.3950 cm³/g), a well-developed pore structure (hierarchical), a high graphitization degree (I_D/I_G = 2.02), the presence of O/N-rich functional groups and Fe-Ox,Ca-Ox, N-doping, as well as synergistic activation by K₂FeO₄ and CaCO₃). The Freundlich and pseudo-second-order models effectively fit the adsorption data, indicating multilayer physicochemical adsorption. Pore filling and π-π interactions were the predominant mechanisms for phenol removal, and H-bonding interactions, Lewis-acid-base interactions, and metal complexation played an important role in enhancing phenol removal. A simple, feasible approach with application potential to organic contaminant/pollutant removal was developed in this study.

Prenatal exposure to particulate matter and term low birth weight: systematic review and meta-analysis

To evaluate the relationships between maternal particulate matter exposure and offspring birth weight. Studies were categorized into three subgroups: term low birth weight (TLBW) among full-term births and all births (regardless of gestational age) and low birth weight (LBW) among all births, based on the search results of MEDLINE and the Web of Science from the inception of the database to April 2022. Subgroup analyses were conducted based on the economic status, region, exposure assessment, risk of bias, and adjustment. Sixty-one studies involving 34,506,975 singleton live births in 15 countries were analyzed. Overall, the risk of bias for most studies (75%) was low. In 39 of 47 term birth studies, the pooled odds ratio of TLBW among term births for per interquartile range (IQR) increases throughout the entire pregnancy was 1.02 (1.01 to 1.03) for PM2.5 and 1.03 (1.01 to 1.05) for PM10 after adjustment for covariates. No significant relevance was detected across each trimester period for PM2.5. A stronger effect was observed during the second trimester (1.03, 1.01 to 1.06) for PM10. There was no increased risk of TLBW in all births associated with IQR increases in PM2.5 and PM10. LBW was associated with PM2.5 exposure in 4 of 7 studies, but statistical heterogeneity was considerable. In the TLBW subgroup analysis, the effects of PM2.5 and PM10 were both greater in studies conducted in advanced countries, studies with low bias, and studies that adjusted for maternal age, infant sex, and parity. Stronger effects were present for PM2.5 exposure collected from monitoring stations and PM10 exposure interpolated from the inverse distance weighting model. TLBW may be associated with prenatal exposure to particulate matter, but no critical windows were identified. Stronger associations were observed in advanced countries. Future original study designs need to consider the impact of different exposure assessment modalities and all possible confounding factors.

Widespread global disparities between modelled and observed mid-depth ocean currents

The mid-depth ocean circulation is critically linked to actual changes in the long-term global climate system. However, in the past few decades, predictions based on ocean circulation models highlight the lack of data, knowledge, and long-term implications in climate change assessment. Here, using 842,421 observations produced by Argo floats from 2001-2020, and Lagrangian simulations, we show that only 3.8% of the mid-depth oceans, including part of the equatorial Pacific Ocean and the Antarctic Circumpolar Current, can be regarded as accurately modelled, while other regions exhibit significant underestimations in mean current velocity. Knowledge of ocean circulation is generally more complete in the low-latitude oceans but is especially poor in high latitude regions. Accordingly, we propose improvements in forecasting, model representation of stochasticity, and enhancement of observations of ocean currents. The study demonstrates that knowledge and model representations of global circulation are substantially compromised by inaccuracies of significant magnitude and direction, with important implications for modelled predictions of currents, temperature, carbon dioxide sequestration, and sea-level rise trends.

Tsuneonella litorea sp. nov., a novel carotenoid-producing bacterium isolated from coastal sediment

A Gram-stain-negative, aerobic, non-motile and pleomorphic bacterium designated as YG55^T was isolated from a coastal sediment sample. Growth was found to occur at 10-37 °C (optimum, 28 °C), at pH 6-9 (optimum, pH 8) and in 0-6 % NaCl (optimum, 1 %). The results of 16S rRNA gene-based analysis showed that strain YG55^T was related to the members of the genus Tsuneonella and shared the highest identity of 99.4 % with Tsuneonella dongtanensis GDMCC 1.2307^T, followed by Tsuneonella troitsensis JCM 17037^T (98.4 %). The phylogenomic results indicated that strain YG55^T formed an independent branch distinct from the reference type strains. The 22.7 and 21.8 % digital DNA-DNA hybridization (dDDH) values and 83.0 and 81.8 % average nucleotide identity (ANI) values between strain YG55^T and the two relatives were below the species definition thresholds of 70 % (dDDH) and 95-96 % (ANI), indicating that the strain represents a novel genospecies. The results of chemotaxonomic characterization indicated that the major cellular fatty acids of strain YG55^T were summed feature 8 (C_18 : 1  ω6c and/or C_18 : 1  ω7c), C_14 : 0 2OH and C_16 : 0; the main polar lipids comprised diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and sphingoglycolipid; the respiratory quinone was ubiquinone-10. The genomic size and DNA G+C contents were 3.03 Mbp and 66.98 %. The strain contained carotenoid biosynthesis genes and could produce carotenoids. Based on its genotypic and phenotypic characteristics, strain YG55^T is concluded to represent a novel species of the genus Tsuneonella, for which the name Tsuneonella litorea sp. nov. is proposed. The type strain is YG55^T (=GDMCC 1.2590 ^T=KCTC 82812^T).

Quantifying human mobility resilience to the COVID-19 pandemic: A case study of Beijing, China

Human mobility, as a fundamental requirement of everyday life, has been most directly impacted during the COVID-19 pandemic. Existing studies have revealed its ensuing changes. However, its resilience, which is defined as people's ability to resist such impact and maintain their normal mobility, still remains unclear. Such resilience reveals people's response capabilities to the pandemic and quantifying it can help us better understand the interplay between them. Herein, we introduced an integrated framework to quantify the resilience of human mobility to COVID-19 based on its change process. Taking Beijing as a case study, the resilience of different mobility characteristics among different population groups, and under different waves of COVID-19, were compared. Overall, the mobility range and diversity were found to be less resilient than decisions on whether to move. Females consistently exhibited lower resilience than males; middle-aged people exhibited the lowest resilience under the first wave of COVID-19 while older adult's resilience became the lowest during the COVID-19 rebound. With the refinement of pandemic-control measures, human mobility resilience was enhanced. These findings reveal heterogeneities and variations in people's response capabilities to the pandemic, which can help formulate targeted and flexible policies, and thereby promote sustainable and resilient urban management.

Human health risk-based soil environmental criteria (SEC) for park soil in Beijing, China

Urban parks are important places that allow urban residents to experience nature but are also associated with the risk of exposure to contaminated soil. Therefore, it is necessary to establish appropriate soil environment criteria (SEC) to manage park soil quality. Studies on the demographic characteristics and behavioral patterns of urban park visitors are helpful for the selection of sensitive receptors and the determination of parameters in the establishment of SEC. This study explored the park visitors' demographic characteristics and behavioral patterns, and applied the results to derive SEC. Eighty-six parks in Beijing were selected, and mobile phone data were obtained to analysis the demographic characteristics and residence time of the visitors. Kruskal-Wallis test, kernel density estimation and random forest model were used for data analysis. The CLEA model was used to derive SEC. The results showed that the demographic characteristics and behavioral patterns of visitors in different types of parks were quite different. Parks were mostly used by males and visitors aged 31-45. Most visitors stayed in the park for 1-2 h, and the distance from a given visitor's home to the park was the most important factor affecting stay time. Then, several parameters such as the parameters related to the receptors and occupation period were optimized, and the SEC of sensitive parks and non-sensitive parks were derived. Exposure frequency may be the main reason for the difference of SEC between the two types of parks. The SECs of sensitive parks were higher than the soil screening values (SSVs) for class 1 land in GB36600-2018, indicating that the current SSVs for some parks may be too conservative. This study provides a reference for the formulation and revision of soil environmental standards for park land, and suggests strengthening research on human behavioral patterns.

Developments of Interfacial Measurement Using Cavity Scanning Microwave Microscopy

In the field of materials research, scanning microwave microscopy imaging has already become a vital research tool due to its high sensitivity and nondestructive testing of samples. In this article, we review the main theoretical and fundamental components of microwave imaging, in addition to the wide range of applications of microwave imaging. Rather than the indirect determination of material properties by measuring dielectric constants and conductivity, microwave microscopy now permits the direct investigation of semiconductor devices, electromagnetic fields, and ferroelectric domains. This paper reviews recent advances in scanning microwave microscopy in the areas of resolution and operating frequency and presents a discussion of possible future industrial and academic applications.

Ruegeria alba sp. nov., Isolated from a Tidal Flat Sediment

A novel Gram-staining-negative, aerobic, rod-shaped, and white-colored bacterium designated as 1NDH52C^T was isolated from a tidal flat sediment and its taxonomic position was determined using a polyphasic taxonomic approach. The microorganism was found to grow at 10-37 °C, pH 6.0-9.0, and in the presence of 0-2% (w/v) NaCl, and to hydrolyze gelatin and aesculin. The major cellular fatty acid of strain 1NDH52C^T was summed feature 8 (C_19:1 ω7c and/or C_18:1 ω6c); the polar lipids comprised diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, an aminolipid, and a lipid; the respiratory quinone was ubiquinone-10. The 16S rRNA gene-based phylogenetic analysis showed that strain 1NDH52C^T was closely related to members of the genus Ruegeria with the identity of 98.2% to the type strain Ruegeria pomeroyi DSM 15711^T. The genome DNA G + C content of strain 1NDH52C^T was 63.6%. The phylogenomic analysis indicated that strain 1NDH52C^T formed an independent branch distinct from reference type strains of species within this genus. Digital DNA-DNA hybridization and average nucleotide identity values between strain 1NDH52C^T and reference strains were, respectively, 19.1-41.5% and 78.3-91.3%, which are far below the thresholds of 70% and 95-96% for species definition, respectively, indicating that strain 1NDH52C^T represents a novel genospecies of the genus Ruegeria. Based on phenotypic and genotypic data, strain 1NDH52C^T is concluded to represent a novel species of the genus Ruegeria, for which the name Ruegeria alba sp. nov., is proposed. The type strain of the species is 1NDH52C^T (= GDMCC 1.2382^T = KCTC 82664^T).

Analysis of changes in population's cross-city travel patterns in the pre- and post-pandemic era: A case study of China

The coronavirus disease (COVID-19) outbreak has immensely changed people's travel behaviour. The changes in travel behaviour have had a huge impact on different industries, such as consumption, entertainment, commerce, office, and education. This study investigates the impact of COVID-19 on population travel patterns from three aspects: total trips, travel recovery degree, and travel distance. The result indicates that COVID-19 has reduced the total number of cross-city trips and flexible non-work travel; in the post-pandemic era, cross-city travel is mainly short-distance (distance <100 km). This study has significant policymaking implications for governments in countries where the population shares a similar change in travel behaviour.

Urban spatial epidemic simulation model: A case study of the second COVID-19 outbreak in Beijing, China

The second COVID-19 outbreak in Beijing was controlled by non-pharmaceutical interventions, which avoided a second pandemic. Until mass vaccination achieves herd immunity, cities are at risk of similar outbreaks. It is vital to quantify and simulate Beijing's non-pharmaceutical interventions to find effective intervention policies for the second outbreak. Few models have achieved accurate intra-city spatio-temporal epidemic spread simulation, and most modeling studies focused on the initial pandemic. We built a dynamic module of infected case movement within the city, and established an urban spatially epidemic simulation model (USESM), using mobile phone signaling data to create scenarios to assess the impact of interventions. We found that: (1) USESM simulated the transmission process of the epidemic within Beijing; (2) USESM showed the epidemic curve and presented the spatial distribution of epidemic spread on a map; and (3) to balance resources, interventions, and economic development, nucleic acid testing intensity could be increased and restrictions on human mobility in non-epidemic areas eased.

Preclinical development and phase 1 trial of a novel siRNA targeting lipoprotein(a)

Compelling evidence supports a causal role for lipoprotein(a) (Lp(a)) in cardiovascular disease. No pharmacotherapies directly targeting Lp(a) are currently available for clinical use. Here we report the discovery and development of olpasiran, a first-in-class, synthetic, double-stranded, N-acetylgalactosamine-conjugated small interfering RNA (siRNA) designed to directly inhibit LPA messenger RNA translation in hepatocytes and potently reduce plasma Lp(a) concentration. Olpasiran reduced Lp(a) concentrations in transgenic mice and cynomolgus monkeys in a dose-responsive manner, achieving up to over 80% reduction from baseline for 5-8 weeks after administration of a single dose. In a phase 1 dose-escalation trial of olpasiran (ClinicalTrials.gov: NCT03626662 ), the primary outcome was safety and tolerability, and the secondary outcomes were the change in Lp(a) concentrations and olpasiran pharmacokinetic parameters. Participants tolerated single doses of olpasiran well and experienced a 71-97% reduction in Lp(a) concentration with effects persisting for several months after administration of doses of 9 mg or higher. Serum concentrations of olpasiran increased approximately dose proportionally. Collectively, these results validate the approach of using hepatocyte-targeted siRNA to potently lower Lp(a) in individuals with elevated plasma Lp(a) concentration.

How did human dwelling and working intensity change over different stages of COVID-19 in Beijing?

The COVID-19 pandemic has changed human daily activities significantly. Understanding the nature, causes, and extent of these changes is essential to evaluate the pandemic's influence on commerce, transportation, employment, and environment, among others. However, existing studies mainly focus on changes to general human mobility patterns; few have investigated changes in specific human daily activities. Based on one-year longitudinal mobile phone positioning data for more than 31 million users in Beijing, we tracked intensity changes in two basic human daily activities, dwelling and working, over the stages of COVID-19. The results show that during COVID-19 outbreak, human working intensity decreased about 60% citywide, while dwelling intensity decreased about 40% in some work and education areas. After COVID-19 was under control, intensity in most regions has recovered, but that in schools, hotels, entertainment venues, and tourism areas has not. These intensity changes at regional scale are due to behavior changes at individual scale: about 43% of residents left Beijing before COVID-19, while only 16% have returned back; all commuters decreased their commuting times during COVID-19, while only 75% have reverted to normal. The findings reveal variations in human activities caused by COVID-19 that can support targeted urban management in the post-epidemic era.

Phylogenomic Analysis Substantiates the gyrB Gene as a Powerful Molecular Marker to Efficiently Differentiate the Most Closely Related Genera Myxococcus, Corallococcus, and Pyxidicoccus

Rapid and accurate strain identification of the most closely related genera Myxococcus, Corallococcus, and Pyxidicoccus can enhance the efficiency of the mining of novel secondary metabolites through dereplication. However, the commonly used 16S rRNA gene sequencing cannot accurately differentiate members of the three genera above, and the whole-genome sequencing is unable to rapidly and inexpensively provide species assignation toward a large number of isolates. To overcome the limitations, the gyrB gene was investigated as a candidate genetic marker for exploring the phylogenetic relationships of bacteria within the three genera and for developing the gyrB-based typing method. Here, the bacterial phylogeny and species affiliations of the three genera were determined based on the phylogenomic reconstruction and the analysis of digital DNA–DNA hybridization values among 90 genomes, further confirming nine novel taxa and assigning over one-third of genomes to defined species. The phylogenetic relationships of these strains based on the gyrB gene sequences were congruent with those based on their genome sequences, allowing the use of the gyrB gene as a molecular marker. The gyrB gene-specific primers for the PCR-amplification and sequencing of bacteria within the three genera were designed and validated for 31 isolates from our group collection. The gyrB-based taxonomic tool proved to be able to differentiate closely related isolates at the species level. Based on the newly proposed 98.6% identity threshold for the 966-bp gyrB gene and the phylogenetic inference, these isolates were assigned into two known species and eight additional putative new species. In summary, this report demonstrated that the gyrB gene is a powerful phylogenetic marker for taxonomy and phylogeny of bacteria within the closely related genera Myxococcus, Corallococcus, and Pyxidicoccus, particularly in the case of hundreds or thousands of isolates in environmental studies.

Chitinilyticum piscinae sp. nov., isolated from aquaculture water

A novel Gram-stain-negative and rod-shaped bacterial strain, designated as 4Y14^T, was isolated from aquaculture water and characterized by using a polyphasic taxonomic approach. Strain 4Y14^T was found to grow at 10-40 °C (optimum, 28 °C), at pH 7.0-9.0 (optimum, 7.0-8.0) and with 0-2 % NaCl (optimum, 1 %, w/v). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 4Y14^T belonged to the genus Chitinilyticum with high levels of similarity to Chitinilyticum litopenaei c1^T (97.8 %) and Chitinilyticum aquatile c14^T (97.2 %). Phylogenomic analysis indicated that strain 4Y14^T formed an independent branch distinct from the two type strains above. Digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between strain 4Y14^T and the two type strains were, respectively, 25.3 and 25.0 %, and 81.2 and 80.3 %, which were well below the thresholds of 70 % DDH and 95-96 % ANI for species definition, implying that strain 4Y14^T should represent a novel genospecies. The predominant cellular fatty acids of strain 4Y14^T were summed feature 3 (C_16 : 1 ω7c and/or C_16 : 1 ω6c) and iso-C_16 : 0; the major polar lipids were diphosphatidylglycerol, phosphatidylcholine and phosphatidylethanolamine; and the sole respiratory quinone was Q-8. The genomic DNA G+C content was 60.1 mol%. Based on the phenotypic and genotypic analyses, strain 4Y14^T is concluded to represent a novel species of the genus Chitinilyticum, for which the name Chitinilyticum piscinae sp. nov. is proposed. The type strain of the species is 4Y14^T (=GDMCC 1.1934^T=KACC 22080^T).

Salipiger mangrovisoli sp. nov., isolated from mangrove soil and the proposal for the reclassification of Paraphaeobacter pallidus as Salipiger pallidus comb. nov

A novel Gram-stain-negative, aerobic and rod-shaped bacterial strain designated as 6D45A^T was isolated from mangrove soil and characterized using a polyphasic taxonomic approach. Strain 6D45A^T was found to grow at 10-37 °C (optimum, 28 °C), at pH 6.0-9.0 (optimum, 7.0) and in 0-5 % (w/v) NaCl (optimum, 2%). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 6D45A^T fell into the genus Salipiger and shared 99.1 % identity with the closest type strain Salipiger pacificus CGMCC 1.3455^T and less than 97.2 % identity with other type strains of this genus. The 34.8 % digital DNA-DNA hybridization (dDDH) and 88.3 % average nucleotide identity (ANI) values between strain 6D45A^T and the closest relative above were well below recognized thresholds of 70 % DDH and 95-96 % ANI for species definition, implying that strain 6D45A^T should represent a novel genospecies. The phylogenomic analysis indicated that strain 6D45A^T formed an independent branch distinct from reference strains. The predominant cellular fatty acid of strain 6D45A^T was summed feature 8 (C_18 : 1  ω6c and/or C_18 : 1  ω7c, 66.9 %); the polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, two unidentified aminolipids, two unidentified glycolipids and an unknown lipid; the respiratory quinone was Q-10. The genomic DNA G+C content was 66.5 mol %. Based on the phenotypic and genotypic characteristics, strain 6D45A^T is concluded to represent a novel species of the genus Salipiger, for which the name Salipiger mangrovisoli sp. nov., is proposed. The type strain of the species is 6D45A^T (=GDMCC 1.1960^T=KCTC 82334^T). We also propose the reclassification of Paraphaeobacter pallidus as Salipiger pallidus comb. nov. and 'Pelagibaca abyssi' as a species of the genus Salipiger.

Synthesis of a novel cyclopropyl phosphonate nucleotide as a phosphate mimic

The inherent in vivo instability of oligonucleotides presents one of many challenges in the development of RNAi-based therapeutics. Chemical modification to the 5'-terminus serves as an existing paradigm which can make phosphorylated antisense strands less prone to degradation by endogenous enzymes. It has been recently shown that installation of 5'-cyclopropyl phosphonate on the terminus of an oligonucleotide results in greater knockdown of a targeted protein when compared to its unmodified phosphate derivative. In this paper we report the synthesis of a 5'-modified uridine.

Qipengyuania soli sp. nov., Isolated from Mangrove Soil

A novel Gram-stain-negative, non-motile, and rod-shaped bacterial strain, designated as 6D36^T, was isolated from mangrove soil and characterized by using a polyphasic taxonomic approach. Strain 6D36^T was found to grow at 10-37 °C (optimum, 28 °C), at pH 6.0-9.0 (optimum, 7.0) and in 0-8% (w/v) NaCl (optimum, 3%). The predominant cellular fatty acids of strain 6D36^T were summed feature 8 (C_19:1 ω7c and/or C_18:1 ω6c) and C_17:1 ω6c; the major polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, and sphingoglycolipid; the sole respiratory quinone was Q-10. The phylogenetic analysis based on 16S rRNA gene sequences showed that strain 6D36^T fell into the genus Qipengyuania and was closely related to "Erythrobacter mangrovi" MCCC 1K03690^T (98.5%), Qipengyuania citrea CGMCC 1.8703^T (97.6%), and Qipengyuania pelagi JCM 17468^T (97.4%). The phylogenomic analysis indicated that strain 6D36^T formed an independent branch distinct from reference-type strains of species within this genus. The digital DNA-DNA hybridization and average nucleotide identity values between strain 6D36^T and the three type strains above were, respectively, 20.2-21.3% and 79.5-81.5%, of which were far below their respective threshold for species definition, implying that the strain represents a novel genospecies. The genomic DNA G + C content was 63.3%. Based on phenotypic and genotypic characteristics, strain 6D36^T is concluded to represent a novel species of the genus Qipengyuania, for which the name Qipengyuania soli sp. nov., is proposed. The type strain of the species is 6D36^T (= GDMCC 1.1977^T = KCTC 82333^T).

Inhella proteolytica sp. nov. and Inhella gelatinilytica sp. nov., two novel species of the genus Inhella isolated from aquaculture water

The two novel bacterial strains designated 1Y17^T and 4Y10^T from aquaculture water were characterized using a polyphasic taxonomic approach. Phylogenetic analysis of 16S rRNA gene sequences revealed that strains 1Y17^T and 4Y10^T belonged to the genus Inhella and were close to Inhella crocodyli CCP-18^T, Inhella inkyongensis IMCC1713^T and Inhella fonticola TNR-25^T. Strains 1Y17^T and 4Y10^T shared 98.6% identity with each other and less than 99.0% identity with their relatives above. The phylogenomic analysis indicated that the two strains formed two independent branches distinct from their relatives. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between the two strains were 21.3 and 80.9% below the two thresholds of 70% dDDH and 95-96% ANI for species definition; those between the two novel strains and their relatives were far below thresholds for species definition, implying that they represent two novel genospecies. The predominant fatty acids of the two strains were summed feature 3 (C_16:1 ω7c and/or C_16:1 ω6c) and C_16:0; the major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol; the major quinone and polyamine were Q-8 and putrescine. Their genomic DNA G + C contents were 69.3 and 65.0%. The two novel strains can produce poly-β-hydroxybutyrate, matching with the presence of the three synthetic related genes of the phaC-phaA-phaB in their genomes. Based on the genotypic and phenotypic characteristics such as aesculin and gelatin hydrolysis, strains 1Y17^T and 4Y10^T are concluded to represent two novel species of the genus Inhella, for which the names Inhella proteolytica sp. nov. (type strain 1Y17^T = GDMCC 1.1830^T = KACC 21948^T) and Inhella gelatinilytica sp. (type strain 4Y10^T = GDMCC 1.1829^T = KCTC 82338^T) are proposed.

Comparative genomic analysis of the genus Novosphingobium and the description of two novel species Novosphingobium aerophilum sp. nov. and Novosphingobium jiangmenense sp. nov

Members of the genus Novosphingobium are well known for their metabolically versatile and great application potential in pollution elimination. The three novel bacterial strains, designated 4Y4^T, 4Y9, and 1Y9A^T, were isolated from aquaculture water and characterized by using a polyphasic taxonomic approach. The 16S rRNA gene sequences phylogenetic analysis revealed that the three strains belonged to the genus Novosphingobium. The phylogenomic analysis indicated that the three strains formed two independent and robust branches distinct from all reference strains. The analyses of dDDH values and ANIs between the three strains and their relatives further demonstrated that the three strains represented two different novel genospecies. Comparative genomic analysis of the three isolates and 32 type strains of the genus Novosphingobium showed that the most important central metabolic pathways of these strains appeared to be similar, while specific and specialized metabolic pathways were flexible and variable among these strains. Chemotaxonomic characterization exhibited that the predominant cellular fatty acids were summed feature 8, summed feature 3, and C_14:0 2OH; the major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidyldimethylethanolamine, phosphatidylglycerol, and sphingoglycolipid; the major respiratory quinone and polyamine were Q-10 and spermidine. The DNA G + C contents were 67.6 and 64.7 %. Based on the genotypic and phenotypic characteristics, strains 4Y4^T and 1Y9A^T are concluded to represent two novel species of the genus Novosphingobium, for which the names Novosphingobium aerophilum sp. nov. (type strain 4Y4^T = GDMCC 1.1828 ^T = KACC 21946 ^T) and Novosphingobium jiangmenense sp. nov. (type strain 1Y9A^T = GDMCC 1.1936 ^T = KACC 22085 ^T) are proposed.

Roseibium litorale sp. nov., isolated from a tidal flat sediment and proposal for the reclassification of Labrenzia polysiphoniae as Roseibium polysiphoniae comb. nov

A novel Gram-stain-negative, facultatively anaerobic, rod-shaped and non-motile bacterial strain, designated as 4C16A^T, was isolated from a tidal flat sediment and characterized by using a polyphasic taxonomic approach. Strain 4C16A^T was found to grow at 10-40 °C (optimum, 28 °C), at pH 5.0-10.0 (optimum, pH 6.0-7.0) and in 0-6 % (w/v) NaCl (optimum, 1 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 4C16A^T fell into the genus Roseibium, and shared the highest identity of 98.9 % with the closest type strain Roseibium suaedae KACC 13772^T and less than 98.0 % identity with other type strains of recognized species within this genus. The phylogenomic analysis indicated that strain 4C16A^T formed an independent branch within this genus. The 28.6 % digital DNA-DNA hybridization estimate and 85.0 % average nucleotide identity between strains 4C16A^T and R. suaedae KACC 13772^T were the highest, but still far below their respective threshold for species definition, implying that strain 4C16A^T should represent a novel genospecies. The predominant cellular fatty acid was summed feature 8; the polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylmonomethylethanolamine; the respiratory quinones were Q-9 and Q-10. The genomic DNA G+C content was 59.8mol %. Based on phylogenetic analyses and phenotypic and chemotaxonomic characteristics, strain 4C16A^T is concluded to represent a novel species of the genus Roseibium, for which the name Roseibium litorale sp. nov. is proposed. The type strain of the species is 4C16A^T (=GDMCC 1.1932^T=KACC 22078^T). We also propose the reclassification of Labrenzia polysiphoniae as Roseibium polysiphoniae comb. nov. and 'Labrenzia callyspongiae' as Roseibium callyspongiae sp. nov.

Spread of COVID-19 in China: analysis from a city-based epidemic and mobility model

Understanding the processes and mechanisms of the spatial spread of epidemics is essential for making reasonable judgments on the development trends of epidemics and for adopting effective containment measures. Using multi-agent network technology and big data on population migration, this paper constructed a city-based epidemic and mobility model (CEMM) to stimulate the spatiotemporal of COVID-19. Compared with traditional models, this model is characterized by an urban network perspective and emphasizes the important role of intercity population mobility and high-speed transportation networks. The results show that the model could simulate the inter-city spread of COVID-19 at the early stage in China with high precision. Through scenario simulation, the paper quantitatively evaluated the effect of control measures "city lockdown" and "decreasing population mobility" on containing the spatial spread of the COVID-19 epidemic. According to the simulation, the total number of infectious cases in China would have climbed to 138,824 on February 2020, or 4.46 times the real number, if neither of the measures had been implemented. Overall, the containment effect of the lockdown of cities in Hubei was greater than that of decreasing intercity population mobility, and the effect of city lockdowns was more sensitive to timing relative to decreasing population mobility.

Quantifying the Time-Lag Effects of Human Mobility on the COVID-19 Transmission: A Multi-City Study in China

The first wave of the 2019 novel coronavirus (COVID-19) epidemic in China showed there was a lag between the reduction in human mobility and the decline in COVID-19 transmission and this lag was different in cities. A prolonged lag would cause public panic and reflect the inefficiency of control measures. This study aims to quantify this time-lag effect and reveal its influencing socio-demographic and environmental factors, which is helpful to policymaking in controlling COVID-19 and other potential infectious diseases in the future. We combined city-level mobility index and new case time series for 80 most affected cities in China from Jan 17 to Feb 29, 2020. Cross correlation analysis and spatial autoregressive model were used to estimate the lag length and determine influencing factors behind it, respectively. The results show that mobility is strongly correlated with COVID-19 transmission in most cities with lags of 10 days (interquartile range 8 - 11 days) and correlation coefficients of 0.68 ± 0.12. This time-lag is consistent with the incubation period plus time for reporting. Cities with a shorter lag appear to have a shorter epidemic duration. This lag is shorter in cities with larger volume of population flow from Wuhan, higher designated hospitals density and urban road density while economically advantaged cities tend to have longer time lags. These findings suggest that cities with compact urban structure should strictly adhere to human mobility restrictions, while economically prosperous cities should also strengthen other non-pharmaceutical interventions to control the spread of the virus.

Synthesis of Fused Oxepane HIV Integrase Inhibitor MK-1376

Controlling the absolute and relative stereochemistry of a seven-membered oxepane in the formation of HIV integrase inhibitor MK-1376 was accomplished through a strategy involving the use of asymmetric allylation and stereoconvergent, substrate-directed installation of an amine fragment. Surprising reactivity was demonstrated during the asymmetric allylation in which the allyl-pyrimidone product was formed reversibly. The stereoconvergent amine addition was accomplished through an elimination/addition sequence involving a quinone methide reactive intermediate, and nucleophilic trapping of the reactive quinone methide intermediate with methylamine. This novel approach delivered MK-1376, offering 100-fold greater productivity and 50-fold less waste than the initial synthetic chemistry route.

Proposal for transfer of Defluviimonas alba to the genus Frigidibacter as Frigidibacter mobilis nom. nov

A polyphasic taxonomic study was undertaken to clarify the exact position of the type strain cai42^T of the species Defluviimonas alba Pan et al. 2015. The results of the 16S rRNA gene sequence analysis indicated that the two sequences from cai42^T shared 99.6 and 99.7 % similarity to that of the type strain SP32^T of the species Frigidibacter albus and formed a coherent clade in the phylogenetic tree. Whole genomic comparison between cai42^T and SP32^T yielded a digital DNA-DNA hybridization estimate of 36.3 %, an average nucleotide identity of 88.8 % and an average amino acid identity of 89.8 %, clearly indicating that the two strains should belong to two genospecies of the same genus. The close relationship between the two strains was underpinned by the results of genome-based phylogenetic analysis. Although cai42^T and SP32^T shared similar physiological and biochemical properties, some striking differences, such as mobility, the temperature range for growth and the polar lipid components, could distinguish them as separate species. Therefore, the comparative phenotypic and genotypic analyses supported the incorporation of Defluviimonas alba into the genus Frigidibacter as Frigidibacter mobilis nom. nov. with the type strain cai42^T (=CGMCC 1.12518^T=LMG 27406^T).

Paracoccus bengalensis is a later heterotypic synonym of Paracoccus versutu

The present study aimed to examine the taxonomic relationship between two species, Paracoccus bengalensis Ghosh et al. 2006 and Paracoccus versutus (Harrison 1983) Katayama et al. 1996. Comparison of 16S rRNA gene sequences revealed that P. bengalensis JJJ^T was highly similar (99.9 %) to P. versutus A2^T. The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that the two strains formed a tight cluster within the genus Paracoccus. Whole genomic comparison between the two strains showed a digital DNA-DNA hybridization estimate of 82. 0 % and an average nucleotide identity value of 98.2 %, clearly indicating that the two strains were members of the same species. Moreover, the type strains of both species shared similar physiological and biochemical properties and fatty acids profiles. Based on genotypic and phenotypic evidence, we conclude that Paracoccus bengalensis Ghosh et al. 2006 is a later heterotypic synonym of Paracoccus versutus (Harrison 1983) Katayama et al. 1996 according to the priority of publication and validation of the name.

Evaluating the cumulative and time-lag effects of drought on grassland vegetation: A case study in the Chinese Loess Plateau

The increased frequency of drought events in recent years is known to be responsible for significantly altering plant biodiversity in many of Earth's ecosystems, though the specifics of vegetation-drought interactions, especially the cumulative and time-lag responses, remains unclear. This study aimed to quantitatively investigate how grassland vegetation over the Chinese Loess Plateau (CLP) reacts to drought, specifically the observed cumulative and time-lag effects which are caused, using a combination of the Normalized Difference Vegetation Index (NDVI) and a multiple time-scale drought index (Standardized Precipitation and Evapotranspiration Index, SPEI). Our results revealed that while drought conditions have widespread cumulative impacts on grass growth in the CLP, the time lag effect of drought covered about half of the total area of the CLP. The cumulative effect of drought on grass was found to take place over various time scales, ranging from 5 to 10 months, while the time lag effect occurred within 2-3 months. The different response time of vegetation growth to the cumulative effect of drought in the CLP was found to be highly related to different water conditions. The accumulated months and mean r_max-cum both had a significant negative correlation with the mean annual SPEI (R² = 0.90, P < 0.001; R² = 0.70, P < 0.001, respectively). The lagged months and mean r_max-lag were also found to be negatively correlated with the mean annual SPEI (R² = 0.547, P < 0.05; R² = 0.785, P < 0.01, respectively).

COVID-19: Challenges to GIS with Big Data

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GIS with big data provides geospatial information to fight COVID-19.

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Big data showed power on epidemic transmission analysis and prevention decision making support.

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Challenges still continue in data aggregation, knowledge discovery, and dynamic expression.

The outbreak of the 2019 novel coronavirus disease (COVID-19) has caused more than 100,000 people infected and thousands of deaths. Currently, the number of infections and deaths is still increasing rapidly. COVID-19 seriously threatens human health, production, life, social functioning and international relations. In the fight against COVID-19, Geographic Information Systems (GIS) and big data technologies have played an important role in many aspects, including the rapid aggregation of multi-source big data, rapid visualization of epidemic information, spatial tracking of confirmed cases, prediction of regional transmission, spatial segmentation of the epidemic risk and prevention level, balancing and management of the supply and demand of material resources, and social-emotional guidance and panic elimination, which provided solid spatial information support for decision-making, measures formulation, and effectiveness assessment of COVID-19 prevention and control. GIS has developed and matured relatively quickly and has a complete technological route for data preparation, platform construction, model construction, and map production. However, for the struggle against the widespread epidemic, the main challenge is finding strategies to adjust traditional technical methods and improve speed and accuracy of information provision for social management. At the data level, in the era of big data, data no longer come mainly from the government but are gathered from more diverse enterprises. As a result, the use of GIS faces difficulties in data acquisition and the integration of heterogeneous data, which requires governments, businesses, and academic institutions to jointly promote the formulation of relevant policies. At the technical level, spatial analysis methods for big data are in the ascendancy. Currently and for a long time in the future, the development of GIS should be strengthened to form a data-driven system for rapid knowledge acquisition, which signifies that GIS should be used to reinforce the social operation parameterization of models and methods, especially when providing support for social management.

Pollution exacerbates China's water scarcity and its regional inequality

Inadequate water quality can mean that water is unsuitable for a variety of human uses, thus exacerbating freshwater scarcity. Previous large-scale water scarcity assessments mostly focused on the availability of sufficient freshwater quantity for providing supplies, but neglected the quality constraints on water usability. Here we report a comprehensive nationwide water scarcity assessment in China, which explicitly includes quality requirements for human water uses. We highlight the necessity of incorporating water scarcity assessment at multiple temporal and geographic scales. Our results show that inadequate water quality exacerbates China's water scarcity, which is unevenly distributed across the country. North China often suffers water scarcity throughout the year, whereas South China, despite sufficient quantities, experiences seasonal water scarcity due to inadequate quality. Over half of the population are affected by water scarcity, pointing to an urgent need for improving freshwater quantity and quality management to cope with water scarcity.

A coherent nanomechanical oscillator driven by single-electron tunnelling

A single-electron transistor embedded in a nanomechanical resonator represents an extreme limit of electron-phonon coupling. While it allows fast and sensitive electromechanical measurements, it also introduces backaction forces from electron tunnelling that randomly perturb the mechanical state. Despite the stochastic nature of this backaction, it has been predicted to create self-sustaining coherent mechanical oscillations under strong coupling conditions. Here, we verify this prediction using real-time measurements of a vibrating carbon nanotube transistor. This electromechanical oscillator has some similarities with a laser. The single-electron transistor pumped by an electrical bias acts as a gain medium and the resonator acts as a phonon cavity. Although the operating principle is unconventional because it does not involve stimulated emission, we confirm that the output is coherent. We demonstrate other analogues of laser behaviour, including injection locking, classical squeezing through anharmonicity, and frequency narrowing through feedback.

China's improving inland surface water quality since 2003

Increased human activity threatens inland water quality in China. Major efforts have been made to alleviate water pollution since 2001. Understanding how water quality responds to these forces can help to guide future efforts to maintain water security and sustainability. We here analyzed the nationwide variability of inland water quality across China from 2003 to 2017 and its responses to anthropogenic discharges. We show that water quality has been improved markedly or was maintained at favorable levels over the country because of reduced discharges in the industrial, rural, and urban residential sectors. However, growing discharges from the agricultural sector threaten these gains. Moreover, the present status of water pollution is relatively severe in north and northeast China. Our findings suggest that China's water quality would further benefit from more flexible strategies for mitigation measures, which respond to regional differences in the factors that influence water pollution levels in specific regions.

Adolescent dental arch development among Southern Chinese in Hong Kong: a geometric morphometric approach

This study aimed to investigate changes in types of dental arch form during adolescence and explore adolescent changes in size and form of dental arch. Hong Kong Chinese were recruited and digital dental arch models were obtained at ages 12, 15, and 18 years. Geometric morphometrics was used to investigate adolescent changes of dental arch form. There were 225 participants from whom digital models at all three age periods were available. Three types of dental arch form were identified through clustering. Significant changes (p < 0.001) in types of dental arch form were noted during age 12–18 years. During age 12–18 years, significant changes in centroid size and form of dental arch were observed (p < 0.001). No significant changes were observed during 15–18 years. Adolescent changes of dental arch form occur primarily during age 12–15 years, whereas dental arch form was relatively stable during age 15–18 years.

Spatial and demographic disparities in short stature among school children aged 7-18 years: a nation-wide survey in China, 2014

OBJECTIVES

To identify spatial disparities and demographic characteristics of short stature, we analysed the prevalence of short stature collected in a nationwide health survey.

SETTINGS

Data were obtained from the 2014 Chinese National Survey on Students Constitution and Health (a cross-sectional study of China). Participants came from 30 provinces, autonomous regions, and municipalities (except Tibet, Hong Kong, Macao, and Taiwan).

PARTICIPANTS

There were 213 795 Han school children between 7 and 18 years old enrolled in our study. All participants were sampled by stratified cluster.

PRIMARY AND SECONDARY OUTCOME MEASURES

Short stature; Chinese and WHO age-specific and gender-specific height growth references were used for short stature assessment.

RESULTS

The age-standardised and age-gender-standardised prevalence of short stature nationwide was 3.70% and 2.69% according to Chinese and WHO growth references, respectively. The short stature prevalence differed significantly among age groups, urban and rural areas, and regions with different socioeconomic development levels (all p<0.0001). The prevalence was 2.23% in urban versus 5.12% in rural areas (p<0.001). The prevalence was 2.60% in developed, 3.72% in intermediately developed, and 4.69% in underdeveloped regions (p<0.0001). These values were all according to China's growth reference, but similar patterns were observed on prevalence based on the WHO reference. The spatial distribution of prevalence of short stature presented a clustered pattern. Moran's I value was 0.474 (p<0.001) and 0.478 (p<0.001) according to the Chinese and WHO growth references, respectively. The southwest part of China showed a higher prevalence of short stature, whereas lower prevalence of short stature was observed mainly in the northeast part of China.

CONCLUSIONS

There is an appreciably high prevalence of short stature in rural, underdeveloped areas of China. There are high prevalence spatial clusters of short stature in southwestern China. This provides corroborating evidence for a tailored strategy on short stature prevention and reduction in special areas.

Kriging methods with auxiliary nighttime lights data to detect potentially toxic metals concentrations in soil

The spatial distribution of potentially toxic metals (PTMs) has been shown to be related to anthropogenic activities. Several auxiliary variables, such as those related to remote sensing data (e.g. digital elevation models, land use, and enhanced vegetation index) and soil properties (e.g. pH, soil type and cation exchange capacity), have been used to predict the spatial distribution of soil PTMs. However, these variables are mostly focused on natural processes or a single aspect of anthropogenic activities and cannot reflect the effects of integrated anthropogenic activities. Nighttime lights (NTL) images, a representative variable of integrated anthropogenic activities, may have the potential to reflect PTMs distribution. To uncover this relationship and determine the effects on evaluation precision, the NTL was employed as an auxiliary variable to map the distribution of PTMs in the United Kingdom. In this study, areas with a digital number (DN) ≥ 50 and an area > 30 km² were extracted from NTL images to represent regions of high-frequency anthropogenic activities. Subsequently, the distance between the sampling points and the nearest extracted area was calculated. Barium, lead, zinc, copper, and nickel concentrations exhibited the highest correlation with this distance. Their concentrations were mapped using distance as an auxiliary variable through three different kriging methods, i.e., ordinary kriging (OK), cokriging (CK), and regression kriging (RK). The accuracy of the predictions was evaluated using the leave-one-out cross validation method. Regardless of the elements, CK and RK always exhibited lower mean absolute error and root mean square error, in contrast to OK. This indicates that using the NTL as the auxiliary variable indeed enhanced the prediction accuracy for the relevant PTMs. Additionally, RK showed superior results in most cases. Hence, we recommend RK for prediction of PTMs when using the NTL as the auxiliary variable.

Education, Altitude, and Humidity Can Interactively Explain Spatial Discrepancy and Predict Short Stature in 213,795 Chinese School Children

Backgrounds and Objectives: The north-south height distinctions in Chinese children suggest that some geographical-climatic factors could determine height variation of short stature. In a national health survey, we aimed to explore the spatial distribution of short stature on city scales, and detect its socio-economic and geographical-climatic factors. Methods: Data on the prevalence of short stature were obtained from a 2014 cross-sectional survey of China (CNSSCH). In total, 213,795 Han Chinese students aged 7-18 years, from 106 cities across 30 provinces, were included. Both China and World Health Organization (WHO) growth references were adopted to define short stature. Results: A spatial clustering was apparent in the distribution of short stature. After multivariable adjustment, altitude and humidity significantly increased the risk of high prevalence in short stature, according to the WHO (odds ratio [OR] = 1.61 and 1.26, 95% confidence interval [CI]: 1.20-2.17 and 1.03-1.54) and China (OR = 1.54 and 1.26; 95% CI: 1.15-2.05 and 1.02-1.55) growth references. Additionally, education significantly decreased the risk of high prevalence in short stature according to the WHO (OR = 0.40; 95% CI: 0.22-0.74) and China (OR = 0.42; 95% CI: 0.22-0.77) growth references. Combining both altitude >400 m and education <9 years, as well as education <9 years and humidity >70%, received the largest effect-size estimate, and significance retained after multivariable adjustment. Conclusions: Our findings indicate that high altitude and humidity increased the risk of high prevalence in short stature, high education was associated with low prevalence. Additionally, we observed possible interactions between education and altitude/humidity. They may interactively explain spatial discrepancy and predict short stature in Chinese school children. Further validations are necessary.

Abstract 36: Factor XII RNAi-based Therapeutic as a Prophylactic Anti-thrombotic Therapy

Introduction: Current anticoagulants effectively prevent thromboembolic (TBE) events, but unmet medical need remains due to elevated risk of major bleeding events, particularly where Factor Xa inhibitors are contraindicated. Factor XII (F12) zymogen initiates the intrinsic coagulation pathway through both autocleavage and Factor XI cleavage. F12 deficient mice show protection from induced thrombosis without increased bleeding risk. F12 deficiency in humans is not associated with increased bleeding risk, suggesting F12 is not essential for hemostasis.

Methods: Hepatocyte-targeted RNA interference (RNAi) triggers for reducing liver F12 expression were developed for subcutaneous (SQ) administration. Specific rodent/human/non-human primate (NHP) cross-reactive RNAi triggers were designed in silico and screened for knockdown activity in vitro and in wild-type mice. Structure activity relationship (SAR) studies of active RNAi triggers identified optimal modifications for lead identification. Candidate RNAi triggers were evaluated for activity and safety in NHPs. In addition, candidate RNAi triggers were evaluated for activity in two rodent models of thrombosis and bleeding risk.

Results: F12 RNAi triggers exhibited significant and sustained knockdown of serum F12 levels in both mice and NHPs. SAR studies enabled identification of a candidate lead molecule that demonstrated >95% knockdown after a single 1 mg/kg dose in mice. Evaluation of two SQ doses of this RNAi trigger in NHPs demonstrated >93% knockdown of serum F12 levels at nadir with durable knockdown of >90% for over 5 weeks after the final dose. Concomitant increases in coagulation biomarker aPTT were observed, consistent with functional F12 depletion. Both arteriovenous shunt studies in rats and FeCl 3 -induced TBE studies in mice exhibited prevention of clot formation after F12 knockdown. Importantly, F12 knockdown did not increase bleeding times in explicit hemostasis studies in mice.

Conclusions: Development of a SQ-administered F12-specific RNAi trigger offers potential for a novel, infrequently dosed prophylactic treatment for TBE without increased bleeding risk. Administration by medical personnel would eliminate adherence concerns inherent to current therapies.