121 research outputs found
Temporal Variability of Groundwater Chemistry and Relationship with Water-table Fluctuation in the Jianghan Plain, Central China
AbstractSamples were collected every month from 39 monitoring wells over a period of 1 year and three months (from Jan 2013 to Mar 2014) in the Jianghan alluvial plain in the middle reaches of the Yangtze river, central China, to evaluate the temporal variability of groundwater composition for As and other constituents. The concentrations of K,Na,Ca,Mg in groundwater generally varied less than 30%, whereas concentrations of the redox-sensitive components (Fe,NH4-N,S and As) varied greater over time. In wells tapping the confined aquifers with depth of 25m, concentrations of groundwater As were much higher and ranged up to760 ±320μg/L seasonally. Higher As concentration were associated with an increasing percentage of As(III) in rainy season and a decrease towards the end of dry season, indicating a reductive mobilization responding to groundwater level fluctuation
Hydrogeochemical Characteristics of High As and High F Groundwater in Hangjinhouqi, Hetao Plain, China
AbstractHangjinhouqi is one of the most serious endemic arsenic and fluorosis areas in Hetao Plain, China. Groundwater samples (n=97) and two sediment cores issued from boreholes were collected to characterize the hydrogeochemistry of groundwater and sediment lithology of aquifers. Results showed that arsenic and fluoride content in groundwater range from 1 to 1093μg/L and from 0.30 to 6.01mg/L, respectively. The highest concentrations are mainly found in the flat areas of the Yin Mountains. As and F are not correlated, suggesting that their origin and/or geochemical processes leading to their release to groundwater are different. Between 15 and 45m of depth, both arsenic and fluoride are more easily released into groundwater. The external environment of high As and high F groundwater formation consisted of a lake-based geographical environment in a long term and closed geological structure, arid and semi-arid climatic conditions, as well as hydrogeological characteristics
(2,2′-Bipyridine-κ2 N,N′)bis(N-ethyl-N-methyldithiocarbamato-κ2 S,S′)zinc(II)
The complete molecule of the title compound, [Zn(C4H8NS2)2(C10H8N2)], is generated by crystallographic twofold symmetry, with the Zn atom lying on the rotation axis; the axis also bisects the central C—C bond of the 2,2′-bipyridine molecule. The metal atom is chelated by two S,S′-bidentate dithiocarbamate anions and the N,N′-bidentate heterocycle, resulting in a distorted cis-ZnN2S4 octahedral geometry. The methyl and ethyl groups of the anion are statistically disordered
Identification of the phosphorylation sites on the E3 ubiquitin ligase Pellino that are critical for activation by IRAK1 and IRAK4
The E3 ubiquitin ligase Pellino can be activated by phosphorylation in vitro, catalyzed by IL-1 receptor-associated kinase 1 (IRAK1) or IRAK4. Here, we show that phosphorylation enhances the E3 ligase activity of Pellino 1 similarly with any of several E2-conjugating enzymes (Ubc13-Uev1a, UbcH4, or UbcH5a/5b) and identify 7 amino acid residues in Pellino 1 whose phosphorylation is critical for activation. Five of these sites are clustered between residues 76 and 86 (Ser-76, Ser-78, Thr-80, Ser-82, and Thr-86) and decorate a region of antiparallel β-sheet, termed the “wing,” which is an appendage of the forkhead-associated domain that is thought to interact with IRAK1. The other 2 sites are located at Thr-288 and Ser-293, just N-terminal to the RING-like domain that carries the E3 ligase activity. Unusually, the full activation of Pellino 1 can be achieved by phosphorylating any one of several different sites (Ser-76, Thr-86, Thr-288, or Ser-293) or a combination of other sites (Ser-78, Thr-80, and Ser-82). These observations imply that dephosphorylation of multiple sites is required to inactivate Pellino 1, which could be a device for prolonging Pellino's E3 ubiquitin ligase activity in vivo
Electroacupuncture and human iPSC-derived small extracellular vesicles regulate the gut microbiota in ischemic stroke via the brain-gut axis
Electroacupuncture (EA) and induced pluripotent stem cell (iPSC)-derived small extracellular vesicles (iPSC-EVs) have substantial beneficial effects on ischemic stroke. However, the detailed mechanisms remain unclear. Here, we explored the mechanisms underlying the regulation of EA and iPSC-EVs in the microbiome-gut-brain axis (MGBA) after ischemic stroke. Ischemic stroke mice (C57BL/6) were subjected to middle cerebral artery occlusion (MCAO) or Sham surgery. EA and iPSC-EVs treatments significantly improved neurological function and neuronal and intestinal tract injury, downregulated the levels of IL-17 expression and upregulated IL-10 levels in brain and colon tissue after cerebral ischemia−reperfusion. EA and iPSC-EVs treatments also modulated the microbiota composition and diversity as well as the differential distribution of species in the intestines of the mice after cerebral ischemia−reperfusion. Our results demonstrated that EA and iPSC-EVs treatments regulated intestinal immunity through MGBA regulation of intestinal microbes, reducing brain and colon damage following cerebral ischemia and positively impacting the outcomes of ischemic stroke. Our findings provide new insights into the application of EA combined with iPSC-EVs as a treatment for ischemic stroke
Solar Ring Mission: Building a Panorama of the Sun and Inner-heliosphere
Solar Ring (SOR) is a proposed space science mission to monitor and study the
Sun and inner heliosphere from a full 360{\deg} perspective in the ecliptic
plane. It will deploy three 120{\deg}-separated spacecraft on the 1-AU orbit.
The first spacecraft, S1, locates 30{\deg} upstream of the Earth, the second,
S2, 90{\deg} downstream, and the third, S3, completes the configuration. This
design with necessary science instruments, e.g., the Doppler-velocity and
vector magnetic field imager, wide-angle coronagraph, and in-situ instruments,
will allow us to establish many unprecedented capabilities: (1) provide
simultaneous Doppler-velocity observations of the whole solar surface to
understand the deep interior, (2) provide vector magnetograms of the whole
photosphere - the inner boundary of the solar atmosphere and heliosphere, (3)
provide the information of the whole lifetime evolution of solar featured
structures, and (4) provide the whole view of solar transients and space
weather in the inner heliosphere. With these capabilities, Solar Ring mission
aims to address outstanding questions about the origin of solar cycle, the
origin of solar eruptions and the origin of extreme space weather events. The
successful accomplishment of the mission will construct a panorama of the Sun
and inner-heliosphere, and therefore advance our understanding of the star and
the space environment that holds our life.Comment: 41 pages, 6 figures, 1 table, to be published in Advances in Space
Researc
Perspective on ultramicroporous carbon as sulphur host for Li–S batteries
Lithium-sulphur (Li-S) batteries are currently considered as next-generation battery technology. Sulphur is an attractive positive electrode for lithium metal batteries, mainly due to its high capacity (1675 mAh g-1) and high specific energy (2600 Wh kg-1). The electrochemical reaction of lithium with sulphur in non-aqueous electrolytes results in the formation of electrolyte soluble intermediate lithium-polysulphides. The dissolved polysulphides shuttle to the anode and get reduced at the anode resulting in Li metal corrosion. The solubility of polysulphide gradually reduces the amount of sulphur in the cathode, thereby limiting the cycle life of Li-S batteries. Several strategies have been proposed to improve the cycling stability of Li-S batteries. A unique approach to eliminate the polysulphide shuttle is to use ultramicroporous carbon (UMC) as a host for sulphur. The pore size of UMC which is below 7 Å, is the bottleneck for carbonate solvents to access sulphur/polysulphides confined in the pores, thereby preventing the polysulphide dissolution. This perspective article will emphasise the role of UMC host in directing the lithiation mechanism of sulphur and in inhibiting polysulphide dissolution, including the resulting parasitic reaction on the lithium anode. Further, the challenges that need to be addressed by UMC-S based Li-S batteries, and the strategies to realise high power density, high Coulombic efficiency, and resilient Li-S batteries will be discussed
Effects of Treatment Setting on Outcomes of Flexibly-Dosed Intensive Cognitive Behavioral Therapy for Pediatric OCD : A Randomized Controlled Pilot Trial
Funding Information: The study authors would like to acknowledge the planning support of Drs. Eric Storch and Katherine Martinez, the recruitment and administrative support of the Provincial OCD Program Team at BC Children's Hospital, and the participation of all families. Funding. This study was supported by postdoctoral awards to RS from the Michael Smith Foundation for Health Research (#17821) and the BC Children's Hospital Research Institute. Both awards provided salary support for RS as well as research funds to support study implementation (e.g., staff salaries, participant reimbursement, etc.). A private donation to the Provincial OCD Program via the BC Children's Hospital Foundation also supported some research costs. Funding Information: This study was supported by postdoctoral awards to RS from the Michael Smith Foundation for Health Research (#17821) and the BC Children’s Hospital Research Institute. Both awards provided salary support for RS as well as research funds to support study implementation (e.g., staff salaries, participant reimbursement, etc.). A private donation to the Provincial OCD Program via the BC Children’s Hospital Foundation also supported some research costs. Publisher Copyright: © Copyright © 2021 Selles, Naqqash, Best, Franco-Yamin, Qiu, Ferreira, Deng, Hannesdottir, Oberth, Belschner, Negreiros, Farrell and Stewart.Introduction: Optimizing individual outcomes of cognitive-behavioral therapy (CBT) remains a priority. Methods: Youth were randomized to receive intensive CBT at a hospital clinic (n = 14) or within their home (n = 12). Youth completed 3 × 3 h sessions (Phase I) and up to four additional 3-h sessions as desired/needed (Phase II). An independent evaluator assessed youth after Phase I, Phase II (when applicable), and at 1- and 6-months post-treatment. A range of OCD-related (e.g., severity, impairment) and secondary (e.g., quality of life, comorbid symptoms) outcomes were assessed. Results: Families' satisfaction with the treatment program was high. Of study completers (n = 22), five youth (23%) utilized no Phase II sessions and 9 (41%) utilized all four (Median Phase II sessions: 2.5). Large improvements in OCD-related outcomes and small-to-moderate benefits across secondary domains were observed. Statistically-significant differences in primary outcomes were not observed between settings; however, minor benefits for home-based treatment were observed (e.g., maintenance of gains, youth comfort with treatment). Discussion: Intensive CBT is an efficacious treatment for pediatric OCD. Families opted for differing doses based on their needs. Home-based treatment, while not substantially superior to hospital care, may offer some value, particularly when desired/relevant. Clinical Trial Registration: www.ClinicalTrials.gov; https://clinicaltrials.gov/ct2/show/NCT03672565, identifier: NCT03672565.Peer reviewe
Layer-by-Layer Assembled Antisense DNA Microsponge Particles for Efficient Delivery of Cancer Therapeutics
Antisense oligonucleotides can be employed as a potential approach to effectively treat cancer. However, the inherent instability and inefficient systemic delivery methods for antisense therapeutics remain major challenges to their clinical application. Here, we present a polymerized oligonucleotides (ODNs) that self-assemble during their formation through an enzymatic elongation method (rolling circle replication) to generate a composite nucleic acid/magnesium pyrophosphate sponge-like microstructure, or DNA microsponge, yielding high molecular weight nucleic acid product. In addition, this densely packed ODN microsponge structure can be further condensed to generate polyelectrolyte complexes with a favorable size for cellular uptake by displacing magnesium pyrophosphate crystals from the microsponge structure. Additional layers are applied to generate a blood-stable and multifunctional nanoparticle via the layer-by-layer (LbL) assembly technique. By taking advantage of DNA nanotechnology and LbL assembly, functionalized DNA nanostructures were utilized to provide extremely high numbers of repeated ODN copies for efficient antisense therapy. Moreover, we show that this formulation significantly improves nucleic acid drug/carrier stability during in vivo biodistribution. These polymeric ODN systems can be designed to serve as a potent means of delivering stable and large quantities of ODN therapeutics systemically for cancer treatment to tumor cells at significantly lower toxicity than traditional synthetic vectors, thus enabling a therapeutic window suitable for clinical translation.United States. Dept. of Defense. Ovarian Cancer Research Program (Teal Innovator Award Grant OC120504)Natural Sciences and Engineering Research Council of Canada (Postdoctoral Fellowship)National Institutes of Health (U.S.) (Ruth L. Kirschstein National Research Service Award 1F32EB017614-01)National Science Foundation (U.S.). Graduate Research Fellowshi
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