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1.
Insects ; 15(5)2024 May 15.
Article in English | MEDLINE | ID: mdl-38786913

ABSTRACT

Potamanthidae belongs to the superfamily Ephemeroidea but has no complete mt genome released in the NCBI (except for two unchecked and one partial mt genome). Since the sister clade to Potamanthidae has always been controversial, we sequenced seven mt genomes of Potamanthidae (two species from Rhoenanthus and five species from Potamanthus) in order to rebuild the phylogenetic relationships of Potamanthidae in this study. The divergence time of Potamanthidae was also investigated by utilizing five fossil calibration points because of the indeterminate origin time. In addition, because Rhoenanthus coreanus and Potamanthus luteus are always in low-temperature environments, we aimed to explore whether these two species were under positive selection at the mt genome level. Amongst the 13 PCGs, CGA was used as the start codon in COX1, whereas other genes conformed to initiating with an ATN start codon. From this analysis, UUA (L), AUU (I), and UUU (F) had the highest usage. Furthermore, the DHU arm was absent in the secondary structure of S1 in all species. By combining the 13 PCGs and 2 rRNAs, we reconstructed the phylogenetic relationship of Potamanthidae within Ephemeroptera. The monophyly of Potamanthidae and the monophyly of Rhoenanthus and Potamanthus were supported in the results. The phylogenetic relationship of Potamanthidae + (Ephemeridae + Polymitarcyidae) was also recovered with a high prior probability. The divergence times of Potamanthidae were traced to be 90.44 Mya (95% HPD, 62.80-121.74 Mya), and the divergence times of Rhoenanthus and Potamanthus originated at approximately 64.77 Mya (95% HPD, 43.82-88.68 Mya), thus belonging to the late Pliocene Epoch or early Miocene Epoch. In addition, the data indicated that R. coreanus was under negative selection and that ATP8 and ND2 in Potamanthidae had a high evolutionary rate.

2.
Spectrochim Acta A Mol Biomol Spectrosc ; 315: 124304, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38636424

ABSTRACT

A ratiometric sensor with ultralow background is highly desired due to its low environmental influence and high sensitivity. Herein, inspired by the solubility difference of carboxylate in aqueous and organic solvents, we prepared a core-shell structure porous zirconia-covalent organic framework (COF) composite through thermal hydrolysis of UiO-66-COF precursors in organic alkali solution. The ligand 2-aminoterephthalic acids (H2BDC-NH2) of UiO-66 were transformed into 2-aminoterephthalate salts (ATA salts) that existed in zirconium-oxo clusters building units. The composites emitted only yellow emission (597 nm) from the COF in organic solvent due to the insolubility of ATA salts that induce aggregation-caused quenching (ACQ) and the protection of the COF shell. Contrarily, when water was added into mixture, the ATA salts were released into solution and its fluorescence recovered at 446 nm, while the fluorescence of COF was quenched due to the blockage of the intramolecular charge transfer (ICT) process by water. Thus, a high-sensitivity ratiometric fluorescence method is obtained with ultralow background signal and fast response (less than 1 min) for sensing water in organic solvent. We believe that the proposed ratiometric fluorescence sensor based on the zirconia-COF composite will provide the guidance for detection with wide applications.

3.
JMIR Mhealth Uhealth ; 12: e51478, 2024 Apr 30.
Article in English | MEDLINE | ID: mdl-38687568

ABSTRACT

BACKGROUND: The COVID-19 pandemic has significantly reduced physical activity (PA) levels and increased sedentary behavior (SB), which can lead to worsening physical fitness (PF). Children and adolescents may benefit from mobile health (mHealth) apps to increase PA and improve PF. However, the effectiveness of mHealth app-based interventions and potential moderators in this population are not yet fully understood. OBJECTIVE: This study aims to review and analyze the effectiveness of mHealth app-based interventions in promoting PA and improving PF and identify potential moderators of the efficacy of mHealth app-based interventions in children and adolescents. METHODS: We searched for randomized controlled trials (RCTs) published in the PubMed, Web of Science, EBSCO, and Cochrane Library databases until December 25, 2023, to conduct this meta-analysis. We included articles with intervention groups that investigated the effects of mHealth-based apps on PA and PF among children and adolescents. Due to high heterogeneity, a meta-analysis was conducted using a random effects model. The Cochrane Risk of Bias Assessment Tool was used to evaluate the risk of bias. Subgroup analysis and meta-regression analyses were performed to identify potential influences impacting effect sizes. RESULTS: We included 28 RCTs with a total of 5643 participants. In general, the risk of bias of included studies was low. Our findings showed that mHealth app-based interventions significantly increased total PA (TPA; standardized mean difference [SMD] 0.29, 95% CI 0.13-0.45; P<.001), reduced SB (SMD -0.97, 95% CI -1.67 to -0.28; P=.006) and BMI (weighted mean difference -0.31 kg/m2, 95% CI -0.60 to -0.01 kg/m2; P=.12), and improved muscle strength (SMD 1.97, 95% CI 0.09-3.86; P=.04) and agility (SMD -0.35, 95% CI -0.61 to -0.10; P=.006). However, mHealth app-based interventions insignificantly affected moderate to vigorous PA (MVPA; SMD 0.11, 95% CI -0.04 to 0.25; P<.001), waist circumference (weighted mean difference 0.38 cm, 95% CI -1.28 to 2.04 cm; P=.65), muscular power (SMD 0.01, 95% CI -0.08 to 0.10; P=.81), cardiorespiratory fitness (SMD -0.20, 95% CI -0.45 to 0.05; P=.11), muscular endurance (SMD 0.47, 95% CI -0.08 to 1.02; P=.10), and flexibility (SMD 0.09, 95% CI -0.23 to 0.41; P=.58). Subgroup analyses and meta-regression showed that intervention duration was associated with TPA and MVPA, and age and types of intervention was associated with BMI. CONCLUSIONS: Our meta-analysis suggests that mHealth app-based interventions may yield small-to-large beneficial effects on TPA, SB, BMI, agility, and muscle strength in children and adolescents. Furthermore, age and intervention duration may correlate with the higher effectiveness of mHealth app-based interventions. However, due to the limited number and quality of included studies, the aforementioned conclusions require validation through additional high-quality research. TRIAL REGISTRATION: PROSPERO CRD42023426532; https://tinyurl.com/25jm4kmf.


Subject(s)
Exercise , Mobile Applications , Pandemics , Physical Fitness , Telemedicine , Adolescent , Child , Humans , COVID-19/prevention & control , Exercise/physiology , Health Promotion/methods , Mobile Applications/standards , Mobile Applications/statistics & numerical data , Pandemics/prevention & control , Physical Fitness/physiology , Randomized Controlled Trials as Topic , Telemedicine/standards , Infection Control
4.
Nat Microbiol ; 9(3): 712-726, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38443574

ABSTRACT

Cell division is fundamental to all cellular life. Most archaea depend on either the prokaryotic tubulin homologue FtsZ or the endosomal sorting complex required for transport for division but neither system has been robustly characterized. Here, we show that three of the four photosynthesis reaction centre barrel domain proteins of Haloferax volcanii (renamed cell division proteins B1/2/3 (CdpB1/2/3)) play important roles in cell division. CdpB1 interacts directly with the FtsZ membrane anchor SepF and is essential for cell division, whereas deletion of cdpB2 and cdpB3 causes a major and a minor division defect, respectively. Orthologues of CdpB proteins are also involved in cell division in other haloarchaea, indicating a conserved function of these proteins. Phylogenetic analysis shows that photosynthetic reaction centre barrel proteins are widely distributed among archaea and appear to be central to cell division in most if not all archaea.


Subject(s)
Haloferax volcanii , Photosynthetic Reaction Center Complex Proteins , Phylogeny , Cell Division , Haloferax volcanii/genetics , Photosynthesis
5.
Front Plant Sci ; 14: 1301117, 2023.
Article in English | MEDLINE | ID: mdl-38046600

ABSTRACT

Developing and planting salt-tolerant plants has become a promising way to utilize saline-alkali land resources and ensure food security. Root-associated microbes of salt-tolerant plants have been shown to promote plant growth and alleviate high salt stress, yet very little is known about the salt resistance mechanisms of core microbes in different niches. This study characterized the microbial community structures, assembly processes, and functional profiles in four root-related compartments of two salt-tolerant plants by amplicon and shotgun metagenomic sequencing. The results showed that both plants significantly altered the microbial community structure of saline soils, with greater microbial alpha diversity in the rhizosphere or rhizoplane compared with bulk soils. Stochastic process dominated the microbial assembly processes, and the impact was stronger in Suaeda salsa than in S. glauca, indicating that S. salsa may have stronger resistance abilities to changing soil properties. Keystone species, such as Pseudomonas in the endosphere of S. glauca and Sphingomonas in the endosphere of S. salsa, which may play key roles in helping plants alleviate salt stress, were identified by using microbial co-occurrence network analysis. Furthermore, the microbiomes in the rhizoplane soils had more abundant genes involved in promoting growth of plants and defending against salt stress than those in bulk soils, especially in salt-tolerant S. salsa. Moreover, microbes in the rhizoplane of S. salsa exhibited higher functional diversities, with notable enrichment of genes involved in carbon fixation, dissimilar nitrate reduction to ammonium, and sulfite oxidation. These findings revealed differences and similarities in the microbial community assembly, functional profiles and keystone species closely related to salt alleviation of the two salt-tolerant plants. Overall, our study provides new insights into the ecological functions and varied strategies of rhizosphere microbes in different plants under salt stress and highlights the potential use of keystone microbes for enhancing salt resistance of plants.

6.
bioRxiv ; 2023 Mar 28.
Article in English | MEDLINE | ID: mdl-37090588

ABSTRACT

Cell division is fundamental to all cellular life. Most of the archaea employ one of two alternative division machineries, one centered around the prokaryotic tubulin homolog FtsZ and the other around the endosomal sorting complex required for transport (ESCRT). However, neither of these mechanisms has been thoroughly characterized in archaea. Here, we show that three of the four PRC (Photosynthetic Reaction Center) barrel domain proteins of Haloferax volcanii (renamed Cell division proteins B1/2/3 (CdpB1/2/3)), play important roles in division. CdpB1 interacts directly with the FtsZ membrane anchor SepF and is essential for division, whereas deletion of cdpB2 and cdpB3 causes a major and a minor division defect, respectively. Orthologs of CdpB proteins are also involved in cell division in other haloarchaea. Phylogenetic analysis shows that PRC barrel proteins are widely distributed among archaea, including the highly conserved CdvA protein of the crenarchaeal ESCRT-based division system. Thus, diverse PRC barrel proteins appear to be central to cell division in most if not all archaea. Further study of these proteins is expected to elucidate the division mechanisms in archaea and their evolution.

7.
Chem Asian J ; 18(1): e202201092, 2023 Jan 03.
Article in English | MEDLINE | ID: mdl-36415140

ABSTRACT

Visible-light-mediated oxyarylation and hydroarylation of alkenes with aryl halides using formate salts as the reductant and hydrogen source under ambient conditions were developed. These protocols represent rare catalyst-free examples of the realization of such transformations. Using styrenes as substrates, oxyarylation could occur smoothly. Whereas, hydroarylation proceeds employing electron deficient alkenes. Moreover, dehalogenation proceeds successfully in the absence of alkenes. We expected that this method could provide a valuable strategy for the functionalization of aryl halides.

8.
J Cardiovasc Pharmacol ; 80(3): 417-429, 2022 09 01.
Article in English | MEDLINE | ID: mdl-35900905

ABSTRACT

ABSTRACT: Prolonged and intense stress can exceed the body's normal self-regulation and limited compensatory and repair capacity, resulting in pathological damage to the body. In this study, we established a rat stress myocardial injury (SMI) model to explore the protective effect of melatonin (MLT) on SMI and its possible mechanisms of action. Adult female Sprague Dawley (SD) rats were randomly divided into 5 groups: blank control group (NC), SMI group, MLT low-dose group, MLT medium-dose group, and MLT high-dose group, and 10 rats in each group were used to establish a SMI model by the water immersion restraint method. We observed the changes in body weight and tail vein glucose of each group. Serum levels of corticosterone (Cort), creatine kinase isoenzyme (CK-MB), and Troponin Ⅰ (Tn-Ⅰ) and activity of lactic acid dehydrogenase were measured by ELISA. Transcriptome sequencing was used to find differentially expressed genes in the control and model groups, and the results were verified by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR). HE staining was used to visualize the pathological changes in the heart tissue of each group, and Western blot was used to study the differences in protein expression in the cardiomyocytes of each group to further corroborate the results. The body weight growth rate of rats in the SMI group was significantly lower than that of the NC group ( P < 0.01), and the body weight growth rate of rats in the MLT high-dose group was significantly higher than that of the SMI group ( P < 0.05) with no significant difference compared with the NC group rats. The mean blood glucose of rats in the SMI group was significantly higher compared with the NC group ( P < 0.001), while the mean blood glucose of rats in the MLT administration groups was dose-dependently reduced compared with the SMI group. By RNA-seq and bioinformatics tools such as KEGG and Gene ontology, we found that the circadian clock-related genes Ciart , Arnt1 , Per1 , and Dbp were significantly downregulated in the SMI group during water immersion stress, and differentially expressed genes were enriched in the p38MAPK signaling pathway and p53 signaling pathway. Moreover, genes related to inflammation and apoptosis were differentially expressed. ELISA results showed that Cort, CK-MB, and Tn-Ⅰ levels were significantly higher in the SMI group compared with the NC group ( P < 0.01) and melatonin reduced the levels of Cort, CK-MB, and Tn-Ⅰ and decreased lactic acid dehydrogenase activity in rat serum. HE staining results showed that melatonin could attenuate stress-generated myocardial injury. Western blot showed that melatonin reduced the expression of p38MAPK, p53, Bax, and caspase-3 and increased the expression of Bcl-2 protein in rat heart. Melatonin can inhibit myocardial injury caused by water immersion, and its mechanism of action may be related to the regulation of the expression of circadian clock genes such as Ciart , Arnt1 , Per1 , and Dbp ; the inhibition of the expression of proapoptotic proteins such as p38MAPK, p53, Bax, and caspase-3; and the increase of the expression of Bcl-2 antiapoptotic protein.


Subject(s)
Melatonin , Myocardial Reperfusion Injury , Animals , Apoptosis , Blood Glucose/metabolism , Body Weight , Caspase 3/metabolism , Creatine Kinase, MB Form/metabolism , Female , Lactic Acid/metabolism , Lactic Acid/pharmacology , Melatonin/pharmacology , Myocardial Reperfusion Injury/pathology , Myocardium/metabolism , Myocytes, Cardiac , Oxidoreductases/metabolism , Oxidoreductases/pharmacology , Proto-Oncogene Proteins c-bcl-2/metabolism , Rats , Rats, Sprague-Dawley , Tumor Suppressor Protein p53/metabolism , Water/metabolism , Water/pharmacology , bcl-2-Associated X Protein/metabolism
9.
Chin J Integr Med ; 28(10): 872-878, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35723814

ABSTRACT

OBJECTIVE: To evaluate the efficacy and safety of Tibetan medicine Ruyi Zhenbao Pills (RZPs) in the treatment of patients with motor and sensory dysfunction after stroke. METHODS: A total of 120 convalescent stroke patients hospitalized in the Rehabilitation Department of Guangdong Provincial Hospital of Chinese Medicine from June 2017 to December 2019 were enrolled in this trial. Patients were assigned to control (60 cases) and research (60 cases) groups by computer random assignment. All patients received internal treatment and modern rehabilitation training. On this basis, the research group was given oral RZPs for 4 weeks, while the control group was given oral placebo. The primary outcome was motor function of the affected side evaluated by simplified Fugl-Meyer Motion Assessment Scale (FMA-M). The secondary outcomes included sensory function, activity of daily living (ADL), quality of life, balance function, and pain, which were assessed by Fugl-Meyer Sensory Assessment Scale (FMA-S), Modified Barthel Index (MBI), Special Scale of the Quality of Life (SS-QOL), Berg Balance Scale (BBS), and Visual Analogue Scale (VAS), respectively. All of the assessments were performed before treatment, and 4 and 8 weeks after treatment. Vital signs, liver and kidney functions, routine blood test, blood coagulation profile, and routine urinalysis of patients were monitored. RESULTS: After 4-week treatment, the FMA-M, BBS and FMA-S scores in the research group significantly increased compared with the control group (P<0.05). At 8-week follow-up, the BBS and MBI scores in the research group were higher than the control group (P<0.05). There was no statistical difference between the 2 groups in the SS-QOL and VAS scores at 4 and 8 weeks (P>0.05). Moreover, after treatment, there was no significant difference in vital signs, liver and kidney functions, blood coagulation function, blood routine and urinalysis between the 2 groups (P>0.05). CONCLUSION: RZPs improved limb motor, balance, and sensory functions of stroke patients during recovery period with good safety. (Trial registration No. NCT04029701).


Subject(s)
Stroke Rehabilitation , Stroke , Activities of Daily Living , Humans , Quality of Life , Stroke/complications , Stroke/drug therapy , Treatment Outcome
10.
Chem Commun (Camb) ; 58(29): 4599-4602, 2022 Apr 07.
Article in English | MEDLINE | ID: mdl-35311867

ABSTRACT

A divergent visible-light-induced Ph3P-promoted method for the synthesis of ureas and formamides from amines and CO2 is reported. Without external additions, a range of ureas could be directly accessed under ambient temperature and pressure. Using triisopropylsilanethiol as the hydrogen source, formamides could be produced.


Subject(s)
Amines , Formamides , Carbon Dioxide , Light , Urea
11.
Huan Jing Ke Xue ; 42(10): 4593-4601, 2021 Oct 08.
Article in Chinese | MEDLINE | ID: mdl-34581101

ABSTRACT

To explore the pollution characteristics and potential health risks of heavy metals in PM2.5 on haze days in Central China, PM2.5 samples were collected from the Huanggang monitoring station, a regional observation point in Central China, between January 13 and 24, 2018. The contents of Cr, Mn, Co, Ni, Cu, Zn, As, Cd, Sn, and Pb in PM2.5 were analyzed by inductively coupled plasma mass spectrometry(ICP-MS), and the enrichment factor method was used to determine the potential risk based on the exposure model recommended by the Environmental Protection Administration(EPA). The results showed that during the observation period, the concentrations of Zn in PM2.5 were highest, and the concentrations of the carcinogens As and Cd were higher than the secondary standard limits of China's ambient air quality standard(GB 3095-2012), with 70% of these elemental concentrations accounting for the largest proportion in the middle haze period. The enrichment factor analysis showed that Cd, Sn, Co, Pb, and Zn were the most abundant elements, especially during the middle haze period, and were mostly derived from transportation and coal combustion. The results of the human health risk assessment showed that exposure via hand-mouth feeding was the main non-carcinogenic risk, and the exposure and non-carcinogenic risks of children were significantly higher than those of adults. Pb poses a non-carcinogenic risk to children, while heavy metals in PM2.5 pose no non-carcinogenic risks to adults and carcinogenic heavy metals pose no carcinogenic risks.


Subject(s)
Metals, Heavy , Particulate Matter , Adult , Child , China , Environmental Monitoring , Humans , Metals, Heavy/analysis , Particulate Matter/analysis , Risk Assessment
12.
Chem Commun (Camb) ; 57(79): 10210-10213, 2021 Oct 05.
Article in English | MEDLINE | ID: mdl-34523655

ABSTRACT

A visible-light-driven direct carbonylative coupling of simple alkanes and alkenes via the combination of a hydrogen atom transfer process and photoredox catalysis has been demonstrated. Employing the N-alkoxyazinium salt as the oxidant and the precursor of an oxygen radical, a variety of α,ß-unsaturated ketones could be obtained in a metal-free fashion.

13.
J Mol Model ; 27(9): 243, 2021 Aug 10.
Article in English | MEDLINE | ID: mdl-34373949

ABSTRACT

In this manuscript, we reported the design and prediction of two furazan-based cage-like molecules and their derivatives using density function theory (DFT). The heat formation and detonation properties were calculated using Hess's law and Kamlet-Jacobs equations with the B3PW91 method. The molecular stability and geometry were analyzed using the M06-2X method, and molecular crystal structures were predicted based on Monte Carlo simulation, while chemical reactive sites were judged using the PBE0 method based on Fukui function. The theoretical calculation result proved that the designed molecules exhibit ideal symmetric cage-like geometry and show superior physicochemical and detonation properties. Compared with traditional energetic materials, the designed molecules display more positive solid heat formation and lower sensitivity. The designed molecules could be considered promising high energy density material candidates with potential synthesis and application value. Two designed molecules display superior detonation performance and ideal completely symmetric cage-like geometry, which were proved theoretically as a promising HEDM candidate. A series of derivatives also exhibited excellent crystal density and physicochemical properties, while with more stable structure.

14.
Org Lett ; 23(13): 5128-5132, 2021 Jul 02.
Article in English | MEDLINE | ID: mdl-34152148

ABSTRACT

1,2-Silylfunctionalization of alkenes is an efficient way to construct highly functionalized silicon-containing compounds. However, examples of 1,2-silylfunctionalization of alkenes using readily available hydrosilanes are limited. Herein, we present a visible-light-mediated divergent 1,2-silylfunctionalization of alkenes using hydrosilane under ambient conditions. A series of ß-alkoxy, ß-alkylthio, ß-hydroxy, and ß-indolyl silanes was obtained in good to excellent yields. Moreover, vinylsilanes were successfully prepared in the absence of an additional nucleophile.

15.
Org Lett ; 23(10): 3939-3943, 2021 May 21.
Article in English | MEDLINE | ID: mdl-33974437

ABSTRACT

A photoinduced oxidative alkoxycarbonylation of alkenes initiated by intermolecular addition of alkoxycarbonyl radicals has been demonstrated. Employing alkyl formates as alkoxycarbonyl radical sources, a range of α,ß-unsaturated esters were obtained with good regioselectivity and E selectivity under ambient conditions.

16.
J Mol Model ; 26(11): 298, 2020 Oct 09.
Article in English | MEDLINE | ID: mdl-33034751

ABSTRACT

A series of energetic compounds derived from substituted oxadiazole molecules which were theoretically proved to have π-π stacking crystal structure using NIC method and QTAIM theory were designed and investigated theoretically as novel high-performance insensitive energetic materials. The heats of formation (HOFs) and detonation parameters were predicted based on Kamlet-Jacobs equations and Born-Haber cycle. All energetic compounds and derivatives were calculated at DFT-B3PW91/6-31G++(d,p) level and exhibited ideal oxygen balance (OB%) (- 19.50~15.68), positive heats of formation (424.0~957.4 kJ/mol), and pleasant crystal density (1.707~1.901 g/cm3). The predicted results revealed that detonation performances of some designed molecules are equal to traditional energetic materials while they are more stable and insensitive that can be considered to have potential synthesis and application value. Graphical abstract BRIEFS Three energetic molecules that proved may have a π-π stacking crystal structure and its derivatives were designed and investigated theoretical as novel high-performance insensitive energetic materials. The most of compounds exhibited positive solid phase heat of formation, idea oxygen balance and structural stability.

17.
Huan Jing Ke Xue ; 41(8): 3475-3483, 2020 Aug 08.
Article in Chinese | MEDLINE | ID: mdl-33124319

ABSTRACT

This study provides data and theoretical support for the prevention and control of air pollution in central China. From January 13, 2018, to January 25, 2018, 48 PM2.5 samples were collected in Huanggang by particulate matter samplers during a severe pollution episode. Twelve elements (Li, Be, V, Se, Sr, Mo, Ag, Ba, Tl, Th, Bi, and U) were analyzed by ICP-MS. A positive definite matrix factor (PMF), trajectory model of the cluster analysis, potential source analysis (PSCF), and the concentration weight analysis method (CWT) were applied to analyze the potential pollution sources and determine the transmission channel. The results showed that the internal cause of the pollution was the appearance of static, stable, and high humidity meteorological conditions, while the external cause was the input of pollution. Five types of pollution source were determined:fuel combustion (10.59%), crustal (24.22%), industry (3.16%), coal (47.57%), and traffic (14.45%). Two main types of air flow path were found; short distance transmission accounted for 62.50% whereas long distance transport accounted for 37.50%. The major contributors to the pollution included central and eastern Hubei, northeastern Hunan, southwestern Anhui, and southern Henan. North-south transmission channels were observed for central China. In addition to local pollution, the impact of regional transmission should not be ignored. In the emergency response period for heavy pollution during the autumn and winter, all regions need to control emission reduction measures. Joint prevention and control are the keys to air pollution control.


Subject(s)
Air Pollutants , Air Pollution , Trace Elements , Air Pollutants/analysis , Air Pollution/analysis , China , Environmental Monitoring , Particulate Matter/analysis
18.
Org Lett ; 22(19): 7460-7464, 2020 Oct 02.
Article in English | MEDLINE | ID: mdl-32941047

ABSTRACT

A photoredox-catalyzed α-C(sp3)-H activation approach of unprotected secondary amines is reported. Such transformations provide facile access to various 1,4-dicarbonyl compounds using readily available amines and α,ß-unsaturated compounds as feedstocks under air conditions. The substrate scope of this method is broad, and a wide array of functional groups are tolerated.

19.
J Mol Model ; 26(7): 175, 2020 Jun 11.
Article in English | MEDLINE | ID: mdl-32529276

ABSTRACT

A series of furazan substituted s-triazine derivatives were designed and investigated theoretically as potential nitrogen-rich high-energy-density materials in this work. Density functional theory (DFT) methods were used to predict the heats of formation (HOFs) and compounds structure was optimized at B3PW91/6-31G++ (d,p) level. The explosive detonation parameters were calculated based on Kamlet-Jacobs equations and Born-Haber cycle. The presence of the -NO2 and - NH2 groups in the same structure were found to be helpful in improving structural stability through intramolecular weak interactions. Most of the designed compounds were characterized by high HOFs (solid-phase heat of information 71.01-518.20 kJ/mol) and crystal density values (1.74-1.90 g/cm3). In the analysis of frontier molecular orbital that some designed compounds chemical activity similar with TATB, but show better detonation performance. The predicted results reveal that some designed nitrogen-rich compounds outperform traditional energetic materials and may be considered as potential candidates for high-energy materials. Graphical Abstract BRIEFS A series of furazan substituted s-triazine derivatives were designed and investigated theoretically as potential nitrogen-rich high-energy-density materials and most of the compounds exhibit high solid phase heat of information and fascinating detonation properties.

20.
Cell Metab ; 31(4): 809-821.e6, 2020 04 07.
Article in English | MEDLINE | ID: mdl-32187526

ABSTRACT

NADH provides electrons for aerobic ATP production. In cells deprived of oxygen or with impaired electron transport chain activity, NADH accumulation can be toxic. To minimize such toxicity, elevated NADH inhibits the classical NADH-producing pathways: glucose, glutamine, and fat oxidation. Here, through deuterium-tracing studies in cultured cells and mice, we show that folate-dependent serine catabolism also produces substantial NADH. Strikingly, when respiration is impaired, serine catabolism through methylene tetrahydrofolate dehydrogenase (MTHFD2) becomes a major NADH source. In cells whose respiration is slowed by hypoxia, metformin, or genetic lesions, mitochondrial serine catabolism inhibition partially normalizes NADH levels and facilitates cell growth. In mice with engineered mitochondrial complex I deficiency (NDUSF4-/-), serine's contribution to NADH is elevated, and progression of spasticity is modestly slowed by pharmacological blockade of serine degradation. Thus, when respiration is impaired, serine catabolism contributes to toxic NADH accumulation.


Subject(s)
Cell Hypoxia , Mitochondria/metabolism , NAD/metabolism , Oxygen/metabolism , Serine/metabolism , Animals , Cell Line , Humans , Mice , Mice, Inbred C57BL , Mice, Nude
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