Altered morphological characteristics and structural covariance connectivity associated with verbal working memory performance in ADHD children.

OBJECTIVES: Deficits in verbal working memory (VWM) observed in attention deficit hyperactivity disorder (ADHD) children can persist into adulthood. Although previous studies have identified brain regions that are activated during VWM tasks, the neural mechanisms underlying the relationship between VWM deficits remain unclear. The objective of this study was to investigate the structural covariance network connectivity and brain morphology changes that are associated with VWM performance in ADHD children. METHODS: For this study, we selected 26 ADHD children and 26 healthy control (HC) participants. Participants were instructed to perform an n-back VWM task and their accuracy and response times were subsequently recorded. This research utilised voxel-based morphometry to measure the grey matter (GM) volume and conducted structural covariance connectivity network analysis to explore the changes of brain in ADHD. RESULTS: Voxel-based morphometry analysis showed that lower GM volume in the right cerebellum lobule VI and the left parahippocampal gryus in ADHD children. Moreover, a positive correlation was found between the GM volume in the right cerebellum lobule VI and the accuracy of 2-back VWM task with verbal, small reward, and delayed feedback (VSD). Structural covariance network analysis found decreased structural connectivity between right cerebellum lobule VI and right precentral gyrus, right postcentral gyrus, left paracentral lobule, right superior parietal gyrus, and left hippocampus in ADHD children. CONCLUSIONS: The low GM volume and altered structural covariance connectivity in the right cerebellum lobule VI might potentially affect VWM performance in ADHD children. ADVANCES IN KNOWLEDGE: The innovation of this study lies in its more focused discussion on the morphological characteristics and structural covariance connectivity of VWM deficits in ADHD children, and the innovative finding of a positive correlation between grey matter volume in the right cerebellum lobule VI and accuracy in completing the 2-back VWM task with verbal instructions, small reward, and delayed feedback (VSD). This expands upon previous research by elucidating the specific brain structures involved in VWM deficits in ADHD children and highlights the potential importance of the cerebellum in this cognitive process. Overall, these innovative findings advance our understanding of the neural basis of ADHD and may have important implications for the development of targeted interventions for VWM deficits.

7-Guanidinyl Coumarins: Synthesis, Photophysical Properties, and Application to Exploit the Pd-Catalyzed Release of Guanidines.

Molecular manipulation of guanidino-containing biomolecules in a cellular environment is fundamental to exploiting protein function and drug release, but currently, there is a lack of suitable methods for reaction screening and monitoring. To exploit the potential of the fluorescent method in this respect, herein, we evaluated a novel array of 7-guanidinyl coumarins by incorporating different substituted guanidino moieties into a coumarin scaffold. These compounds were prepared by guanidinylation reagent S-methylisothiourea or TFA-protected pyrazole-carboxamidine. Examination of their photophysical properties revealed that the fluorescence emission of alkyloxycarbonyl-substituted guanidinyl coumarin was significantly enhanced as compared with the unsubstituted analogue. This dramatic fluorescence difference enabled preliminary exploitation of the Pd-catalyzed release of allyloxycarbonyl (Alloc)-caged guanidinyl coumarin-6 in living cells.

ReACT (redox-activated chemical tagging) chemistry enables direct derivatization and fluorescence detection of S-adenosyl-L-homocysteine (SAH).

S-Adenosyl-L-homocysteine (SAH) is a universal byproduct and product inhibitor of the methyltransferase-catalyzed methylation reaction. Here based on ReACT (redox-activated chemical tagging) chemistry, direct derivatization and fluorescence measurement of SAH were achieved with features such as mild reaction conditions and simple operation.

360° Map Establishment and Real-Time Simultaneous Localization and Mapping Based on Equirectangular Projection for Autonomous Driving Vehicles.

This paper proposes the design of a 360° map establishment and real-time simultaneous localization and mapping (SLAM) algorithm based on equirectangular projection. All equirectangular projection images with an aspect ratio of 2:1 are supported for input image types of the proposed system, allowing an unlimited number and arrangement of cameras. Firstly, the proposed system uses dual back-to-back fisheye cameras to capture 360° images, followed by the adoption of the perspective transformation with any yaw degree given to shrink the feature extraction area in order to reduce the computational time, as well as retain the 360° field of view. Secondly, the oriented fast and rotated brief (ORB) feature points extracted from perspective images with a GPU acceleration are used for tracking, mapping, and camera pose estimation in the system. The 360° binary map supports the functions of saving, loading, and online updating to enhance the flexibility, convenience, and stability of the 360° system. The proposed system is also implemented on an nVidia Jetson TX2 embedded platform with 1% accumulated RMS error of 250 m. The average performance of the proposed system achieves 20 frames per second (FPS) in the case with a single-fisheye camera of resolution 1024 × 768, and the system performs panoramic stitching and blending under 1416 × 708 resolution from a dual-fisheye camera at the same time.

Facile access to S-methyl dithiocarbamates with sulfonium or sulfoxonium iodide as a methylation reagent.

Efficient access to S-methyl dithiocarbamates was achieved with sulfonium or sulfoxonium iodide as a methylation reagent. This method is reliable for the synthesis of dithiocarbamates from primary or secondary amines, with sulfoxonium iodide demonstrating more robust methylation capability than sulfonium iodide. Moreover, it also enables facile access to S-trideuteromethyl dithiocarbamates via sulfoxonium metathesis between sulfoxonium iodide and DMSO-d6 with high yields.

IP3 and calcium signaling involved in the reorganization of the actin cytoskeleton and cell rounding induced by cigarette smoke extract in human endothelial cells.

Smoking increases the risk of cardiovascular disorders and leads to damage caused by inflammation and oxidative stress. The actin cytoskeleton is a key player in the response to inflammatory stimuli and is an early target of cellular oxidative stress. The purpose of this study was to investigate the changes in actin cytoskeleton dynamics in human endothelial EA.hy926 cells exposed to cigarette smoke extract (CSE). Immunostaining revealed that CSE exposure resulted in modification of the actin cytoskeleton and led to cell rounding in a dose- and time-dependent manner. In addition, the intracellular calcium concentration was increased by treatment with CSE. Pretreatment with antioxidants (lipoic acid, glutathione, N-acetyl cysteine, aminoguanidine, α-tocopherol, and vitamin C) significantly attenuated the CSE-induced actin cytoskeleton reorganization and cell rounding. Calcium ion chelators (EGTA, BAPTA-AM AM) and a potent store-operated calcium channel inhibitor (MRS 1845) also reduced CSE-induced intracellular calcium changes and attenuated actin cytoskeleton reorganization and cell morphology change. Moreover, the CSE-induced intracellular calcium increase was suppressed by pretreatment with the inositol trisphosphate receptor (IP3R) inhibitor xestospongin C, the phospholipase C (PLC) inhibitor U-73122, and the protein kinase C (PKC) inhibitor GF109203X. These results suggest that reactive oxygen species production and intracellular calcium increase play an essential role in CSE-induced actin disorganization and cell rounding through a PLC-IP3-PKC signaling pathway. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1293-1306, 2016.

On-road vehicle emission control in Beijing: past, present, and future.

Beijing, the capital of China, has experienced rapid motorization since 1990; a trend that is likely to continue. The growth in vehicles and the corresponding emissions create challenges to improving the urban air quality. In an effort to reduce the impact of vehicle emissions on urban air quality, Beijing has adopted a number of vehicle emission control strategies and policies since the mid 1990 s. These are classified into seven categories: (1) emission control on new vehicles; (2) emission control on in-use vehicles; (3) fuel quality improvements; (4) alternative-fuel and advanced vehicles; (5) economic policies; (6) public transport; and (7) temporal traffic control measures. Many have proven to be successful, such as the Euro emission standards, unleaded gasoline and low sulfur fuel, temporal traffic control measures during the Beijing Olympic Games, etc. Some, however, have been failures, such as the gasoline-to-LPG taxi retrofit program. Thanks to the emission standards for new vehicles as well as other controls, the fleet-average emission rates of CO, HC, NO(X), and PM(10) by each major vehicle category are decreasing over time. For example, gasoline cars decreased fleet-average emission factors by 12.5% for CO, 10.0% for HC, 5.8% for NO(X), and 13.0% for PM(10) annually since 1995, and such a trend is likely to continue. Total emissions for Beijing's vehicle fleet increased from 1995 to 1998. However, they show a clear and steady decrease between 1999 and 2009. In 2009, total emissions of CO, HC, NO(X), and PM(10) were 845,000 t, 121,000 t, 84,000 t, and 3700 t, respectively; with reductions of 47%, 49%, 47%, and 42%, relative to 1998. Beijing has been considered a pioneer in controlling vehicle emissions within China, similar to the role of California to the U.S. The continued rapid growth of vehicles, however, is challenging Beijing's policy-makers.

Structural identification and bioactivities of red-violet pigments present in Basella alba fruits.

Mature Basella alba L. fruit, with dark blue skin and deep red-violet flesh, is a potential source of natural colorants. Its pigment components and bioactivities deserve particular attention and investigation. In this study, fruit flesh was extracted with 80% methanol (containing 0.2% formic acid) and subjected to solid-phase extraction, semipreparative HPLC isolation, mass spectrophotometric analysis, and structural elucidation. The major red pigment was identified as gomphrenin I. Its quantity increased with the increase of fruit maturity. The gomphrenin I extract yield from ripe fruits was 36.1 mg/100 g of fresh weight. In addition to gomphrenin I, betanidin-dihexose and isobetanidin-dihexose were also detected. The antioxidant activities of gomphrenin I determined by Trolox equivalent antioxidant capacity (TEAC), α,α-diphenyl-ß-picrylhydrazyl (DPPH) radical scavenging activity, reducing power, and antioxidative capacity assays were equivalent to 534 µM Trolox, 103 µM butylated hydroxytoluene (BHT), 129 µM ascorbic acid, and 68 µM BHT at 180, 23, 45, and 181 µM, respectively. The anti-inflammatory function was tested at concentrations of 25, 50, and 100 µM in murine macrophages stimulated with lipopolysaccharide (LPS). The results revealed that gomphrenin I suppressed LPS-induced nitric oxide (NO) production in a dose-dependent manner and decreased PGE(2) and IL-1ß secretions at the highest concentration tested. The transcriptional inhibitory activities of gomphrenin I on the expression of inflammatory genes encoding iNOS, COX-2, IL-1ß, TNF-α, and IL-6 were also observed. It is of merit to identify gomphrenin I as a principal pigment of B. alba fruits and as a potent antioxidant and inflammatory inhibitor. These findings suggest that B. alba fruit is a rich source of betalains and has value-added potential for use in the development of food colorants and nutraceuticals.