Whole-genome assembly and evolutionary analysis of the Malus kansuensis (Rosaceae) mitochondrion

Malus kansuensis, which belongs to the family Rosaceae, is an important apple rootstock resource in China. In the present study, the mitochondrial genome of M. kansuensis was sequenced and assembled by high-throughput sequencing (HTS). The genome was 385,436 bp in length, with an obvious (A + T) % bias over (G + C) %. The mitochondrial genome comprised 35 protein-coding genes, 21 tRNA genes, and 3 rRNA genes. The phylogenetic tree results showed that M. kansuensis is very close to M. domestica and M. hupehensis

Thermal decomposition behavior and computational analysis of alpha and beta manganese dioxide nanorods

The thermal stability of materials directly influences their applications. This present work investigates the difference of thermal decomposition behaviors of alpha (α) and beta (β) manganese dioxide (MnO2) nanorods. Differential scanning calorimeter coupled with thermogravimetric analysis is conducted to find the difference of thermal process. The X-ray diffraction analysis and scanning electron microscope are employed to test crystal structures and morphologies at various roasted temperatures, respectively. The activation energy and Debye temperature are calculated to explain the difference in the decomposition process. It is found that β-MnO2 can be fully converted to Mn2O3 after roasting at 650 °C, whereas only part of α-MnO2 has changed. Besides, the β-MnO2 nanorods go through a continuous thinning from room temperature to 500 °C, while the morphology of α-MnO2 remains the same until it reaches over 300 °C. These results suggest that α-MnO2 nanorods have better thermal resistance than β-MnO2, which could facilitate the selection of thermal stable materials for electrochemistry industries and energy materials application.The study at School of Mechanical and Aerospace Engineering, Nanyang Technological University (NTU) was supported by China Scholarship Council (No. 201903170086)

Aerosol Vertical Structure and Optical Properties during Two Dust and Haze Episodes in a Typical Valley Basin City, Lanzhou of Northwest China

The vertical profiles of aerosol optical properties are vital to clarify their transboundary transport, climate forcing and environmental health influences. Based on synergistic measurements of multiple advanced detection techniques, this study investigated aerosol vertical structure and optical characteristics during two dust and haze events in Lanzhou of northwest China. Dust particles originated from remote deserts traveled eastward at different altitudes and reached Lanzhou on 10 April 2020. The trans-regional aloft (~4.0 km) dust particles were entrained into the ground, and significantly modified aerosol optical properties over Lanzhou. The maximum aerosol extinction coefficient (σ), volumetric depolarization ratio (VDR), optical depth at 500 nm (AOD500), and surface PM10 and PM2.5 concentrations were 0.4~1.5 km−1, 0.15~0.30, 0.5~3.0, 200~590 μg/m3 and 134 μg/m3, respectively, under the heavy dust event, which were 3 to 11 times greater than those at the background level. The corresponding Ångström exponent (AE440–870), fine-mode fraction (FMF) and PM2.5/PM10 values consistently persisted within the ranges of 0.10 to 0.50, 0.20 to 0.50, and 0.20 to 0.50, respectively. These findings implied a prevailing dominance of coarse-mode and irregular non-spherical particles. A severe haze episode stemming from local emissions appeared at Lanzhou from 30 December 2020 to 2 January 2021. The low-altitude transboundary transport aerosols seriously deteriorated the air quality level in Lanzhou, and aerosol loading, surface air pollutants and fine-mode particles strikingly increased during the gradual strengthening of haze process. The maximum AOD500, AE440–870nm, FMF, PM2.5 and PM10 concentrations, and PM2.5/PM10 were 0.65, 1.50, 0.85, 110 μg/m3, 180 μg/m3 and 0.68 on 2 January 2021, respectively, while the corresponding σ and VDR at 0.20–0.80 km height were maintained at 0.68 km−1 and 0.03~0.12, implying that fine-mode and spherical small particles were predominant. The profile of ozone concentration exhibited a prominent two-layer structure (0.60–1.40 km and 0.10–0.30 km), and both concentrations at two heights always remained at high levels (60~72 μg/m3) during the entire haze event. Conversely, surface ozone concentration showed a significant decrease during severe haze period, with the peak value of 20~30 μg/m3, which was much smaller than that before haze pollution (~80 μg/m3 on 30 December). Our results also highlighted that the vertical profile of aerosol extinction coefficient was a good proxy for evaluating mass concentrations of surface particulate matters under uniform mixing layers, which was of great scientific significance for retrieving surface air pollutants in remote desert or ocean regions. These statistics of the aerosol vertical profiles and optical properties under heavy dust and haze events in Lanzhou would contribute to investigate and validate the transboundary transport and radiative forcing of aloft aerosols in the application of climate models or satellite remote sensing

Direct Observation of Photoinduced Ultrafast Generation of Singlet and Triplet Quinone Methides in Aqueous Solutions and Insight into the Roles of Acidic and Basic Sites in Quinone Methide Formation

Femtosecond time-resolved transient absorption spectroscopy experiments and density functional theory computations were done for a mechanistic investigation of 3-(1-phenylvinyl)­phenol (<b>1</b>) and 3-hydroxybenzophenone (<b>2</b>) in selected solvents. Both compounds went through an intersystem crossing (ISC) to form the triplet excited states Tππ* and Tnπ* in acetonitrile but behave differently in neutral aqueous solutions, in which a triplet excited state proton transfer (ESPT) induced by the ISC process is also proposed for <b>2</b> but a singlet ESPT without ISC is proposed for <b>1</b>, leading to the production of the triplet quinone methide (QM) and the singlet excited QM species respectively in these two systems. The triplet QM then underwent an ISC process to form an unstable ground state intermediate which soon returned to its starting material <b>2</b>. However, the singlet excited state QM went through an internal conversion process to the ground state QM followed by the formation of its final product in an irreversible manner. These differences are thought to be derived from the slow vinyl C–C rotation and the moderate basicity of the vinyl C atom in <b>1</b> as compared with the fast C–O rotation and the greater basicity of the carbonyl O atom of <b>2</b> after photoexcitation. This can account for the experimental results in the literature that the aromatic vinyl compounds undergo efficient singlet excited state photochemical reactions while the aromatic carbonyl compounds prefer triplet photochemical reactions under aqueous conditions. These results have fundamental and significant implications for understanding of the ESPT reactivity in general, as well as for the design of molecules for efficient QM formation in aqueous media with potential applications in cancer phototherapy

Nitrogen Supply and Leaf Age Affect the Expression of TaGS1 or TaGS2 Driven by a Constitutive Promoter in Transgenic Tobacco

Glutamine synthetase (GS) plays a key role in nitrogen metabolism. Here, two types of tobacco transformants, overexpressing Triticum aestivum GS1 (TaGS1) or GS2 (TaGS2), were analysed. Four independent transformed lines, GS1-TR1, GS1-TR2, GS2-TR1 and GS2-TR2, were used for the nitrogen treatment. Under nitrogen-sufficient conditions, the leaves of GS2-TR showed high accumulation of the TaGS2 transcript, while those of GS1-TR showed a low TaGS1 transcript levels. However, compared with nitrogen-sufficient conditions, the TaGS1 transcript level increased in the leaves under nitrogen starvation, but the TaGS2 transcript level decreased. In addition, the TaGS1 and TaGS2 transcript levels were highest in the middle leaves under nitrogen-sufficient and starvation conditions. These results show that nitrogen supply and leaf age regulate TaGS expression, even when they are driven by a super-promoter. Additionally, in regard to nitrogen metabolism level, the lower leaves of the GS1-TR exhibited lower NH4+ and higher amino acid contents, while the upper leaves exhibited higher amino acid, soluble protein and chlorophyll contents. The leaves of the GS2-TR exhibited lower NH4+ but higher amino acid, soluble protein and chlorophyll contents. Given the role that GS isoforms play in nitrogen metabolism, these data suggest that TaGS1 overexpression may improve nitrogen transport, and that TaGS2 overexpression may improve nitrogen assimilation under nitrogen stress

Molecular Detection of Babesia gibsoni in Cats in China

As there are few studies of Babesia spp. infection in cats in China, or anywhere in the world, the aim of this study was to explore the epidemic features of babesiosis in pet cats in China. In total, 429 blood samples were randomly collected in four different geographical regions. The 18S rRNA gene fragment of Babesia spp. was amplified by nest polymerase chain reaction (PCR), and haplotype and phylogenetic analysis of Babesia were performed to analyze the relationship of this protozoa. The total positive rate of infection was 2.8%. BLAST analysis indicated that Babesia gibsoni was detected in 12 cats. Among these, 4.3%, 3.1%, 0.8% and 2.0% were from Chongqing, Fujian, Hubei and Shandong, respectively. Haplotype and phylogenetic analysis showed that there were nine haplotypes and no obvious genetic variation among B. gibsoni populations. These findings will be helpful for understanding the epidemiology of Babesia spp. in China, and provide a foundation for developing effective preventative strategies

Correction: Yin et al. Molecular Detection of <i>Babesia gibsoni</i> in Cats in China. <i>Animals</i> 2022, <i>12</i>, 3066

In the original publication [...

Let It Flow: A Static Method for Exploring Dynamic Graphs

network Fronto-parietal task control network Salience network Default mode network Fig. 1. Functional brain connectivity summaries of three different subjects from younger to older (from top to bottom). The x-axis represents time; the y-axis represents the connectedness of four different functional regions, which are encoded by different colors. The patterns show that the blue and yellow regions become less connected than the purple region with the increase of age. That is, as aging occurs, these two regions become less connected, indicating the deterioration of functional activity due to brain aging. Abstract — Research into social network analysis has shown that graph metrics, such as degree and closeness, are often used to summarize structural changes in a dynamic graph. However there have been few visual analytics approaches that have been proposed to help analysts study graph evolutions in the context of graph metrics. In this paper, we present a novel approach, called GraphFlow, to visualize dynamic graphs. In contrast to previous approaches that provide users with an animated visualization, GraphFlow offers a static flow visualization that summarizes the graph metrics of the entire graph and its evolution over time. Our solution supports the discovery of high-level patterns that are difficult to identify in an animation or in individual static representations. In addition, GraphFlow provides users with a set of interactions to create filtered views. These views allow users to investigate why a particular pattern has occurred. We showcase the versatility of GraphFlow using two different datasets and describe how it can help users gain insights into complex dynamic graphs

How Does the C–Halogen Bond Break in the Photosubstitution Reaction of 3‑Fluorobenzophenone in Acidic Aqueous Solutions?

The efficient photosubstitution reaction of <i>m</i>-fluorobenzophenone and the related photohydration reactions were systematically investigated in acidic aqueous solutions. The mechanisms and intermediates were directly characterized by femtosecond transient absorption spectroscopy and nanosecond time-resolved resonance Raman spectroscopy, which is supported by density functional theory calculations. This photosubstitution was found to be a two-step process, based on the observation of a <i>meta</i>-hydration intermediate. The protonation of the ketone was confirmed as a crucial precursor step for further photochemical reactions as indicated by the observation of the absorption spectrum of an excited triplet protonated species. More interestingly, the efficient photosubstitution reaction could selectively occur under specific conditions. Control experiments on a series of halogen-substituted benzophenones were conducted to study the influence of the solution acidity, substituent positions, and the kind of substituted halogens on the efficiency in forming the corresponding hydroxyl photosubstitution product. Some practical conditions in predicting the efficiency of the photosubstitution reaction of interest are summarized, and they were successfully used to predict when the photosubstitution reaction takes place for some other halogen-substituted benzophenone derivatives. The driving force of this photosubstitution reaction may provide insights into several possible applications which are also briefly discussed