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ABSTRACT The exploration of protein structure and function stands at the forefront of life science and represents an ever‐expanding focus in the development of proteomics. As mass spectrometry (MS) offers readout of protein conformational changes at both the protein and peptide levels, MS‐based structural proteomics is making significant strides in the realms of structural and molecular biology, complementing traditional structural biology techniques. This review focuses on two powerful MS‐based techniques for peptide‐level readout, namely limited proteolysis‐mass spectrometry (LiP‐MS) and cross‐linking mass spectrometry (XL‐MS). First, we discuss the principles, features, and different workflows of these two methods. Subsequently, we delve into the bioinformatics strategies and software tools used for interpreting data associated with these protein conformation readouts and how the data can be integrated with other computational tools. Furthermore, we provide a comprehensive summary of the noteworthy applications of LiP‐MS and XL‐MS in diverse areas including neurodegenerative diseases, interactome studies, membrane proteins, and artificial intelligence‐based structural analysis. Finally, we discuss the factors that modulate protein conformational changes. We also highlight the remaining challenges in understanding the intricacies of protein conformational changes by LiP‐MS and XL‐MS technologies. [ABSTRACT FROM AUTHOR]

The electrochemical production of hydrogen peroxide (H2O2) using metal‐free catalysts has emerged as a viable and sustainable alternative to the conventional anthraquinone process. However, the precise architectural design of these electrocatalysts poses a significant challenge, requiring intricate structural engineering to optimize electron transfer during the oxygen reduction reaction (ORR). Herein, we introduce a novel design of covalent organic frameworks (COFs) that effectively shift the ORR from a four‐electron to a more advantageous two‐electron pathway. Notably, the JUC‐660 COF, with strategically charge‐modified benzyl moieties, achieved a continuous high H2O2 yield of over 1200 mmol g−1 h−1 for an impressive duration of over 85 hours in a flow cell setting, marking it as one of the most efficient metal‐free and non‐pyrolyzed H2O2 electrocatalysts reported to date. Theoretical computations alongside in situ infrared spectroscopy indicate that JUC‐660 markedly diminishes the adsorption of the OOH* intermediate, thereby steering the ORR towards the desired pathway. Furthermore, the versatility of JUC‐660 was demonstrated through its application in the electro‐Fenton reaction, where it efficiently and rapidly removed aqueous contaminants. This work delineates a pioneering approach to altering the ORR pathway, ultimately paving the way for the development of highly effective metal‐free H2O2 electrocatalysts. [ABSTRACT FROM AUTHOR]

Background: Obstructive sleep apnea hypopnea syndrome (OSAHS) is a serious and potentially life‐threatening disease. Mandibular advancement device (MAD) has the characteristics of non‐invasive, comfortable, portable and low‐cost, making it the preferred treatment for mild‐to‐moderate OSAHS. Our previous studies found that abnormal contractility and fibre type distribution of the genioglossus could be caused by OSAHS. However, whether the mitochondria participate in these tissue changes is unclear. The effect of MAD treatment on the mitochondria of the genioglossus in OSAHS is also uncertain. Objective: To examine the morphology and function of mitochondria from the genioglossus in a rabbit model of obstructive sleep apnea–hypopnea syndrome (OSAHS), as well as these factors after insertion of a mandibular advancement device (MAD). Methods: Thirty male New Zealand white rabbits were randomised into three groups: control, OSAHS and MAD, with 10 rabbits in each group. Animals in Group OSAHS and Group MAD were induced to develop OSAHS by injection of gel into the submucosal muscular layer of the soft palate. The rabbits in Group MAD were fitted with a MAD. The animals in the control group were not treated. Further, polysomnography (PSG) and cone‐beam computed tomography (CBCT) scan were used to measure MAD effectiveness. CBCT of the upper airway and PSG suggested that MAD was effective. Rabbits in the three groups were induced to sleep for 4–6 h per day for eight consecutive weeks. The genioglossus was harvested and detected by optical microscopy and transmission electron microscopy. The mitochondrial membrane potential was determined by laser confocal microscopy and flow cytometry. Mitochondrial complex I and IV activities were detected by mitochondrial complex assay kits. Results: OSAHS‐like symptoms were induced successfully in Group OSAHS and rescued by MAD treatment. The relative values of the mitochondrial membrane potential, mitochondrial complex I activity and complex IV activity were significantly lower in Group OSAHS than in the control group; however, there was no significant difference between Group MAD and the control group. The OSAHS‐induced injury and the dysfunctional mitochondria of the genioglossus muscle were reduced by MAD treatment. Conclusion: Damaged mitochondrial structure and function were induced by OSAHS and could be attenuated by MAD treatment. [ABSTRACT FROM AUTHOR]

Background: Obstructive sleep apnoea (OSA) is an independent risk factor for cardiovascular diseases. We aimed to investigate the role of nuclear factor‐kappa B (NF‐κB) in the changes of cardiac structures in OSA rabbits treated by mandibular advancement device (MAD). Methods: Eighteen male New Zealand white rabbits aged 6 months were randomly divided into three groups: control group, group OSA and group MAD. Hyaluronate gel was injected into the soft palate of the rabbits in group OSA and group MAD to induce OSA. The cone beam computer tomography (CBCT) of the upper airway and polysomnography (PSG) was performed to ensure successful modelling. CBCT and PSG were applied again to detect the effects of MAD treatment. All animals were induced to sleep in a supine position for 4–6 h a day for 8 weeks. Then the levels of NF‐κB, Interleukin 6 (IL‐6), Interleukin 10 (IL‐10) and the proportion of myocardial fibrosis (MF) were detected. Results: The higher activation of NF‐κB, IL‐6 and IL‐10 were found in the OSA group than in the control group, leading to the increase of collagen fibres compared with the control group. Furthermore, the apnoea‐hypopnea index (AHI) was positively correlated with the above factors. There were no significant differences between group MAD and the control group. Conclusion: The NF‐κB pathway was activated in the myocardium of OSA rabbits, which accelerated the development of MF. Early application of MAD could reduce the activation of NF‐κB in the myocardium and prevent the development of MF. [ABSTRACT FROM AUTHOR]

With increasing numbers of environmental conflicts in recent years, Chinese local governments are changing their modes of governance with the aim of addressing these conflicts satisfactorily. Through a case study, we identified shifts in modes of governance from hierarchical to network and from market to hybrid (characterized by a combination of market and hierarchical) in three arenas. Our findings confirm that initiating actors, stakeholder involvement types, rules of interaction, and implementation strategies are useful indicators of shifts in governance modes. Media, protests and policy entrepreneurs in different arenas are important factors in the shift from hierarchical to network governance, while policy entrepreneurs and higher‐level government intervention are crucial factors in the shift from market to a hybrid governance mode. Policy entrepreneurs play an important role in all three arenas. As for theoretical contribution, our research has provided the evidence for non‐hierarchical governance practices in the NIMBY in China. In the future, local governments in China may learn to consider proper governance mode shifts to deal with the NIMBY conflicts in infrastructure planning and construction. [ABSTRACT FROM AUTHOR]

Introduction: Whether the coronavirus disease‐2019 (COVID‐19) pandemic is associated with a long‐term negative impact on acute stroke care remains uncertain. This study aims to compare the timing of key aspects of stroke codes between patients before and after the COVID‐19 pandemic. Methods: This retrospective cohort study was conducted at an academic hospital in Shanghai, China and included all adult patients with acute ischemic stroke hospitalized via the emergency department (ED) stroke pathway during the 24 months since the COVID‐19 outbreak (COVID‐19: January 1, 2020–December 31, 2021). The comparison cohort included patients with ED stroke pathway visits and hospitalizations during the same period (pre‐COVID‐19: January 1, 2018–December 31, 2019). We compared critical time points of prehospital and intrahospital acute stroke care between patients during the COVID‐19 era and patients during the pre‐COVID‐19 era using t test, χ2, and Mann–Whitney U test where appropriate. Results: A total of 1194 acute ischemic stroke cases were enrolled, including 606 patients in COVID‐19 and 588 patients in pre‐COVID‐19. During the COVID‐19 pandemic, the median onset‐to‐hospital time was about 108 min longer compared with the same period of pre‐COVID‐19 (300 vs 192 min, p = 0.01). Accordingly, the median onset‐to‐needle time was 169 min in COVID‐19 and 113 min in pre‐COVID‐19 (p = 0.0001), and the proportion of patients with onset‐to‐hospital time within 4.5 h was lower (292/606 [48.2%] vs 328/558 [58.8%], p = 0.0003) during the pandemic period. Furthermore, the median door‐to‐inpatient admission and door‐to‐inpatient rehabilitation times increased from 28 to 37 h and from 3 to 4 days (p = 0.014 and 0.0001). Conclusions: During the 24 months of COVID‐19, a prolongation of stroke onset to hospital arrival and to intravenous rt‐PA administration times were noted. Meanwhile, acute stroke patients needed to stay in the ED for a longer time before hospitalization. Educational system support and process optimization should be pursued in order to acquire timely delivery of stroke care during the pandemic. [ABSTRACT FROM AUTHOR]

Against the background of regional development, this article analyses the rise and fall of 'thin identities', which tend to be utilitarian and deployed to promote regional development. We focus on two constructed regional identities in the Greater Pearl River Delta (GPRD) in China: Pearl River Delta (PRD) and Guangdong‐Hong Kong‐Macau Greater Bay Area (GBA). We analyse the adoption of these identities through news items published in newspapers in both China's Mainland and Hong Kong. The results show that both economic and political events influence the adoption of thin identities, first PRD and then GBA. In the content analysis of news items, we investigate the pathways to their adoption and possible evolution towards thickness (broader social and cultural embeddedness) by distinguishing economic, political, social, and cultural topics. The wish of policymakers to adopt new thin identities, however, does affect the credibility of existing thick ones, a point deserving of serious consideration. [ABSTRACT FROM AUTHOR]

Climate change and human activities have already caused degradation in a large fraction of vegetation on the Qinghai‐Tibetan Plateau (QTP). Many studies report that climate variability instead of overgrazing has been the primary cause for large‐scale vegetation cover changes on the QTP, for example, Lehnert et al., 2016, https://doi.org/10.1038/srep24367. However, it remains unclear how human activities (mainly livestock grazing) regulate vegetation dynamics under climate change. This paper takes the AVHRR/GIMMS Normalized Difference Vegetation Index (NDVI) as an indicator to analyze the growth status of vegetation zones in the QTP, which has highly sensitive to climate change. The spatiotemporal dynamics of vegetation growth between 1981 and 2015 were analyzed. The dual effects of climate change and human activities were examined by correlation analyses of data from 87 meteorological stations and economic statistical data of the QTP. Results show that: (a) The vegetation in central and southwestern QTP with high altitudes was improving due to the warm‐humid climate trend. An increase in temperature and a reduction in the harsh frigid climate at high altitudes due to global warming has resulted in expansions of the vegetated areas, with the NDVI showing a concordant increase. (b) The degraded areas were mainly confined to the northern and eastern QTP, which have high human and livestock population densities. In comparison to gently changing climate regimes, anthropogenic activities such as chronic concentration of population and livestock in the valleys with a less harsh climate exerts a much stronger pressure on vegetation. The study indicates that the anthropogenic pressures are much more intensive than the impact of climate change and are critical for the conservation and sustainable management of the QTP vegetation. Plain Language Summary: Vegetation dynamics and its type are considered to be critical indicators of different climate regimes and have received significant attention from ecologists and climatologists. However, studies on the shift in vegetation toward higher altitudes and higher latitudes with climate warming from the vegetation zone redistribution perspective are relatively scarce. Our results suggest that the degraded areas of vegetation were mainly confined to the northern and eastern Qinghai‐Tibetan Plateau (QTP), which have high human and livestock population densities. In comparison to gently changing climate regimes, anthropogenic activities such as chronic concentration of population and livestock in the relatively less harsh valleys exerts a much stronger pressure on vegetation. Anthropogenic pressures were therefore found to be far more intensive than the impact of climate change and they were the big threats to the sustainability of the QTP. Key Points: The vegetation with high altitudes was improving due to the warm‐humid climate trendThe degraded vegetation areas were mainly confined to high human and livestock population densitiesAnthropogenic activities such as chronic concentration of population and livestock exerts a much stronger pressure on vegetation [ABSTRACT FROM AUTHOR]

Water radical cations, (H2O)n+•, have attracted considerable attention owing to their potential practical applications in analytical chemistry, structural chemistry, radiotherapy, and radiochemistry. Recently, atmospheric pressure chemical ionization has emerged as a versatile method for direct mass spectrometric analysis. Usually, H3O+ is the major proton donor during ionization and only the pseudo molecular ion peaks, instead of molecular ions are detected. In this work, (H2O)2+• ions with high oxidizability and reactivity were generated using hydrothermally grown TiO2 nanoneedle arrays in combination with a linear ion trap mass spectrometer under low operating voltage and applied to the direct mass spectrometric analysis of a mixture of volatile aromatic hydrocarbons. (H2O)2+• ions were generated with a high absolute ion current of up to 1.07 × 105 counts/s at atmospheric pressure. Using the generated (H2O)2+• as the primary ion permitted the tandem mass spectrometric analysis of a mixed vapor sample of aromatic hydrocarbons. [ABSTRACT FROM AUTHOR]

Reactive gaseous nitrogen (Ngr) emissions significantly affect Earth's climate system. Disagreement exists, however, over Ngr contributions to short‐ versus long‐term climate forcing, from local to global scales and among different gaseous forms, including NH3, NOx, and N2O. Here, we provide a comprehensive inventory of Ngr from China's croplands based on a new bottom‐up, mass flow‐based approach integrated with fine‐resolution agricultural activity data and nitrogen emission factors. We demonstrate that China's croplands emit about 8.87 Tg N to the atmosphere in 2014. Across different prefectures, Ngr emission per capita conforms to a "Kuznets curve," that is, first increases then decreases, along the gradient of increasing urbanization. Ngr emission per gross domestic productivity (GDP) decreases exponentially with increasing urbanization or per capita GDP. Furthermore, climate change impact analyses suggest that the global‐scale warming effect of China's cropland N2O emissions dominate over local cooling effects ascribed to its NH3 and NOx emissions. Plain Language Summary: Reactive gaseous nitrogen, sourced to the world's highest fertilizer application rates in China, imparts local cooling effects on short time scales. The effects are ultimately counterbalanced by nitrous oxide emissions over the long term, leading to substantial warming effects on the global climate system. We base our conclusion on the first‐ever high‐resolution assessment of reactive nitrogen emissions to the atmosphere from China's croplands. Owing to limited high‐resolution reactive gaseous nitrogen emissions data, hitherto, large uncertainties have existed in the detailing the role of China's cropland reactive gaseous nitrogen emissions on climate forcing. This paucity of information poses a challenge for informing China's agricultural sustainability policies with regard to maintaining/increasing agricultural yields while reduces reactive gaseous nitrogen emissions and their warming potential. Our analyses provide essential information for further sustainable N management and the interactions between agriculture and climate change. We provide policy‐relevant information for mitigation targets, including the 2°C limit goal set by the 2015 Paris Agreement of the United Nations Framework Convention on Climate Change, enabling progress related to multiple United Nations Sustainable Development Goals. Key Points: We provide new high‐resolution estimates of reactive gaseous nitrogen (Ngr) emissions from China's croplands and their seasonal dynamicsAcross different prefectures, Ngr emission per capita follows an environmental Kuznets curve against urbanization rateThe overall warming effect of N2O emissions dominate over local cooling effects ascribed to NH3 and NOx emissions each year [ABSTRACT FROM AUTHOR]

This paper reports a power amplifier (PA) terahertz monolithic integrated circuit (TMIC) from 180 to 240 GHz. This amplifier is fabricated from a 0.5‐μm indium phosphide double heterojunction bipolar transistor (InP DHBT) technology, jointly with a thin‐film microstrip wiring environment. Furthermore, an electromagnetic (EM) simulation method is proposed for the parameter extraction of InP DHBTs and amplifier design. This five‐stage amplifier has >6.1 dB S21 gain from 180 to 240 GHz, peaks 10.4 dB S21 gain at 210 GHz. At 213 GHz operation, the saturated output power is 5.8 dBm with 7.3 dB large‐signal gain, and this amplifier occupies 2.52 mm2 including pads. [ABSTRACT FROM AUTHOR]

In this paper, a novel small‐signal equivalent‐circuit model of terahertz InGaAs/InP double‐heterojunction bipolar transistor (DHBT) is presented. Two intrinsic base resistances are introduced to represent the nonuniform extrinsic impedance of base‐emitter and base‐collector junctions separately. This treatment makes the high‐frequency model more close to the triple‐mesa InP DHBT structure. Systematical parasitic parameter extraction method and intrinsic element initialization of a 0.5 μm * 5μm InGaAs/InP DHBT are presented. As a high‐frequency device model, inter‐electrode parasitic capacitances are calculated by three‐dimensional electromagnetic simulation. The proposed model results in a good agreement with measured multibiased S‐parameters up to 325 GHz. [ABSTRACT FROM AUTHOR]

Summary: Maize exhibits marked growth and yield response to supplemental nitrogen (N). Here, we report the functional characterization of a maize NIN‐like protein ZmNLP5 as a central hub in a molecular network associated with N metabolism. Predominantly expressed and accumulated in roots and vascular tissues, ZmNLP5 was shown to rapidly respond to nitrate treatment. Under limited N supply, compared with that of wild‐type (WT) seedlings, the zmnlp5 mutant seedlings accumulated less nitrate and nitrite in the root tissues and ammonium in the shoot tissues. The zmnlp5 mutant plants accumulated less nitrogen than the WT plants in the ear leaves and seed kernels. Furthermore, the mutants carrying the transgenic ZmNLP5 cDNA fragment significantly increased the nitrate content in the root tissues compared with that of the zmnlp5 mutants. In the zmnlp5 mutant plants, loss of the ZmNLP5 function led to changes in expression for a significant number of genes involved in N signalling and metabolism. We further show that ZmNLP5 directly regulates the expression of nitrite reductase 1.1 (ZmNIR1.1) by binding to the nitrate‐responsive cis‐element at the 5′ UTR of the gene. Interestingly, a natural loss‐of‐function allele of ZmNLP5 in Mo17 conferred less N accumulation in the ear leaves and seed kernels resembling that of the zmnlp5 mutant plants. Our findings show that ZmNLP5 is involved in mediating the plant response to N in maize. Significance Statement: In this study, we report the functional characterization of ZmNLP5 for its role in modulating the N response, suggesting that ZmNLP5 is a potential candidate for improving N use efficiency in maize production. [ABSTRACT FROM AUTHOR]

Objective: Medical and recreational cannabis use is increasing significantly, but its impacts on oral health remain unclear. The aim of this study is to investigate the effects of tetrahydrocannabinol (THC), the major active component in cannabis, on periodontal fibroblast cell adhesion and migration to explore its role in periodontal regeneration and wound healing. Material and Methods: The different distribution of cannabinoid receptors 1 (CB1) and 2 (CB2) was characterized in the mouse periodontium. Human periodontal fibroblast cell (HPLF) adhesion and migration was analysed by in vitro wound healing assay with and without THC. The focal adhesion kinase (FAK) signalling pathway was investigated to uncover the underlying cellular mechanism. The receptor dependency of cannabinoid effects was examined by using selective antagonists to block THC. Results: Both CB1 and CB2 were expressed in periodontal tissues but with different expression patterns. Tetrahydrocannabinol promoted periodontal cell wound healing by inducing HPLF cell adhesion and migration. This was mediated by focal adhesion kinase (FAK) activation and its modulation of MAPK activities. The effect of cannabinoids on periodontal fibroblast cell adhesion and migration was mainly dependent on the CB2. Conclusion: These results suggested that cannabinoids may contribute to developing new therapeutics for periodontal regeneration and wound healing. [ABSTRACT FROM AUTHOR]

Sarcoidosis is a systemic granulomatous disease associated with Th1/ regulatory T cells (Treg) paradigm. PI3K/Akt signaling, critical for maintaining Treg's homeostasis, is aberrantly activated in sarcoidosis patients. Here we tested the role of the PI3K inhibitors, LY294002 and BKM120, in immune modulation in experimental pulmonary sarcoidosis, concerning Th1/Th17/Treg immune profile detected by fluorescence‐activated cell sorting analysis or quantitative polymerase chain reaction, as well as the effect on Treg's suppressive functions. Our investigation showed abnormal activation of PI3K/Akt signaling both in lung and Treg in pulmonary sarcoidosis, along with decreased frequency and damaged function of Treg. Blockage of PI3K suppressed this signaling in Treg, rebalanced Th1/Treg, inhibited the production of inflammatory cytokines, and enhanced Treg's function. These results demonstrate the key role of the PI3K/Akt signaling in regulating Th1/Th2 rebalances and indicates that PI3K/Akt signaling is critical for the optimal Treg responses in pulmonary sarcoidosis. Thus, PI3K inhibitors have potential for therapeutic translation, and can be candidate for add‐on drugs to treat pulmonary sarcoidosis. [ABSTRACT FROM AUTHOR]

Porous carbon material has been widely used as the electrode material for supercapacitor owing to distinctive advantages of high electrical conductivity, low cost and availability at ease. In this study, rice‐husk‐derived porous carbon (RHPC) is successfully prepared by employing a new activation agent copper chloride (CuCl2). The morphology and porous structure of RHPC are characterized by scanning electron microscope and N2 adsorption/desorption. The electrochemical performances of RHPC are investigated by alvanostatic charge‐discharge, cyclic voltammetry and electrochemical impedance spectroscopy. The RHPC possesses high porosity and large specific surface area. When used as supercapacitor electrode materials, RHPC exhibits high specific capacitance of 165.23 F⋅g−1 at a current density of 0.5 A⋅g−1, excellent cycle stability and noticeable high‐rate capacity of 151.69 F⋅g−1 even at a high current density of 20 A⋅g−1. More importantly, the preparation of this CuCl2 activator is facile and low‐cost. Besides, the recyclability meet the requirements of environmental concerns. A general method has been developed to prepare hierarchical porous carbon from biomass for supercapacitor applications. The CuCl2 activator convert the precursor into porous structure by etching carbon materials through a redox reaction The rice‐huck‐derived porous carbon (RHPC) possess hierarchical porous structure combined with micropores, mesopores and macropores, preserving the original excellent structure of RH. In additional, yielded RHPC with high specific capacitance,noticeable rate performance and long‐term cycle stability. [ABSTRACT FROM AUTHOR]

This Letter presents an irregular pentagonal patch array antenna with a multilayer structure for dual‐band and multimode orbital angular momentum (OAM) generation. An irregular pentagonal patch antenna with U‐shaped slots resonating at different frequencies is designed as the array's element. The proposed antenna array consists of two uniform circular microstrip antenna arrays and two phase‐shifting feeding networks. It can be used to generate OAM mode l = − 1, 1 at 3 GHz and OAM mode l = −2, 2 at 6 GHz. The simulated near‐field phase distributions images of different OAM modes are obtained, which have verified the OAM generation. This proposed array antenna has the possibility to generate a total of six different OAMs in three frequency bands, by changing the number of array elements and optimising the irregular pentagonal patch antenna. This design may provide a new idea for the generation multimode vortex electromagnetic wave. [ABSTRACT FROM AUTHOR]

Abstract: Hard carbon is regarded as the most promising anode material for commercialization of Na ion batteries because of its high capacity and low cost. At present, the practical utilization of hard carbon anodes is largely limited by the low initial Coulombic efficiency (ICE). Na ions have been found to adopt an adsorption–insertion storage mechanism. In this paper a systematic way to control the defect concentration and porosity of hard carbon with similar overall architectures is shown. This study elucidates that the defects in the graphite layers are directly related to the ICE as they would trap Na ions and create a repulsive electric field for other Na ions so as to shorten the low‐voltage intercalation capacity. The obtained low defect and porosity hard carbon electrode has achieved the highest ICE of 86.1% (94.5% for pure hard carbon material by subtracting that of the conductive carbon black), reversible capacity of 361 mA h g−1, and excellent cycle stability (93.4% of capacity retention over 100 cycles). This result sheds light on feasible design principles for high performance Na storage hard carbon: suitable carbon layer distance and defect free graphitic layers. [ABSTRACT FROM AUTHOR]

Abstract: Central European grasslands are characterized by a wide range of different management practices in close geographical proximity. Site‐specific management strategies strongly affect the biosphere–atmosphere exchange of the three greenhouse gases (GHG) carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4). The evaluation of environmental impacts at site level is challenging, because most in situ measurements focus on the quantification of CO2 exchange, while long‐term N2O and CH4 flux measurements at ecosystem scale remain scarce. Here, we synthesized ecosystem CO2, N2O, and CH4 fluxes from 14 managed grassland sites, quantified by eddy covariance or chamber techniques. We found that grasslands were on average a CO2 sink (−1,783 to −91 g CO2 m−2 year−1), but a N2O source (18–638 g CO2‐eq. m−2 year−1), and either a CH4 sink or source (−9 to 488 g CO2‐eq. m−2 year−1). The net GHG balance (NGB) of nine sites where measurements of all three GHGs were available was found between −2,761 and −58 g CO2‐eq. m−2 year−1, with N2O and CH4 emissions offsetting concurrent CO2 uptake by on average 21 ± 6% across sites. The only positive NGB was found for one site during a restoration year with ploughing. The predictive power of soil parameters for N2O and CH4 fluxes was generally low and varied considerably within years. However, after site‐specific data normalization, we identified environmental conditions that indicated enhanced GHG source/sink activity (“sweet spots”) and gave a good prediction of normalized overall fluxes across sites. The application of animal slurry to grasslands increased N2O and CH4 emissions. The N2O‐N emission factor across sites was 1.8 ± 0.5%, but varied considerably at site level among the years (0.1%–8.6%). Although grassland management led to increased N2O and CH4 emissions, the CO2 sink strength was generally the most dominant component of the annual GHG budget. [ABSTRACT FROM AUTHOR]

It is of sustainable interest to improve the sensitivity and selectivity of the ionization process, especially for direct analysis of complex samples without matrix separation. Herein, four ambient ionization methods including desorption atmospheric pressure chemical ionization (DAPCI), heat-assisted desorption atmospheric pressure chemical ionization (heat-assisted DAPCI),microwave plasma torch (MPT) and internal extractive electrospray ionization (iEESI) were employed for comparative analysis of the navel orange tissue samples by mass spectrometry. The volatile organic compounds (e.g. ethanol, vanillin, leaf alcohol and jasmine lactone) were successfully detected by non-heat-assisted DAPCI-MS, while semi-volatile organic compounds (e.g. 1-nonanol and ethyl nonanoate) together with low abundance of non-volatile organic compounds (e.g. sinensetin and nobiletin) were obtained by heat-assisted DAPCI-MS. Typical nonvolatile organic compounds [e.g. 5-(hydroxymethyl)furfural and glucosan] were sensitively detected with MPT-MS. Compounds of high polarity (e.g. amino acids, alkaloids and sugars) were easily profiled with iEESI-MS. Our data showed that more analytes could be detected when more energy was delivered for the desorption ionization purpose; however, heat-sensitive analytes would not be detected once the energy input exceeded the dissociation barriers of the analytes. For the later cases, soft ionizationmethods such as iEESIwere recommended to sensitively profile the bioanalytes of high polarity. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A new thioimide-based fluorescent 'turn-on' and chromogenic chemodosimeter for highly selective and sensitive detection of Hg2+ has been developed. The chemodosimeter showed not only marked color change of the solution from dark green to colorless upon the addition of Hg2+ ion, but also 100-fold enhancement of the fluorescent intensity in aqueous acetonitrile. The detection mechanism resulted from the Hg2+ induced desulfurization of the thioimide to its imide precursor. When the chemodosimeter was assembled into nanoparticles, it could also exhibit remarkably dual response of color change, fluorescence enhancement, and highly selective and sensitive detection of Hg2+. [ABSTRACT FROM AUTHOR]

A new thioimide-based fluorescent 'turn-on' and chromogenic chemodosimeter for highly selective and sensitive detection of Hg2+ has been developed. The chemodosimeter showed not only marked color change of the solution from dark green to colorless upon the addition of Hg2+ ion, but also 100-fold enhancement of the fluorescent intensity in aqueous acetonitrile. The detection mechanism resulted from the Hg2+ induced desulfurization of the thioimide to its imide precursor. When the chemodosimeter was assembled into nanoparticles, it could also exhibit remarkably dual response of color change, fluorescence enhancement, and highly selective and sensitive detection of Hg2+. [ABSTRACT FROM AUTHOR]

The carbon- and nitrogen-rich soils of montane grasslands are exposed to above-average warming and to altered precipitation patterns as a result of global change. To investigate the consequences of climatic change for soil nitrogen turnover, we translocated intact plant-soil mesocosms along an elevational gradient, resulting in an increase of the mean annual temperature by approx. 2 °C while decreasing precipitation from approx. 1500 to 1000 mm. Following three years of equilibration, we monitored the dynamics of gross nitrogen turnover and ammonia-oxidizing bacteria ( AOB) and archaea ( AOA) in soils over an entire year. Gross nitrogen turnover and gene levels of AOB and AOA showed pronounced seasonal dynamics. Both summer and winter periods equally contributed to cumulative annual N turnover. However, highest gross N turnover and abundance of ammonia oxidizers were observed in frozen soil of the climate change site, likely due to physical liberation of organic substrates and their rapid turnover in the unfrozen soil water film. This effect was not observed at the control site, where soil freezing did not occur due to a significant insulating snowpack. Climate change conditions accelerated gross nitrogen mineralization by 250% on average. Increased N mineralization significantly stimulated gross nitrification by AOB rather than by AOA. However, climate change impacts were restricted to the 2-6 cm topsoil and rarely occurred at 12-16 cm depth, where generally much lower N turnover was observed. Our study shows that significant mineralization pulses occur under changing climate, which is likely to result in soil organic matter losses with their associated negative impacts on key soil functions. We also show that N cycling processes in frozen soil can be hot moments for N turnover and thus are of paramount importance for understanding seasonal patterns, annual sum of N turnover and possible climate change feedbacks. [ABSTRACT FROM AUTHOR]

Fluoxetine has become one of the most promising drugs for improving clinical outcome in patients with cerebral infarction. Although the clinical efficacy of fluoxetine has been preliminarily demonstrated, its mechanism remains unclear. Hypoxia-inducible factor 1-alpha ( HIF-1α) is upstream to Netrin and vascular endothelial growth factor ( VEGF), and under hypoxia conditions it may induce expression of Netrin-1 and VEGF in vascular endothelial cells. We sought to explore whether it can regulate their expression in hypoxia and mediate the effect of fluoxetine in hypoxia. In this study, the effect of hypoxia on the expression of VEGF and Netrin was observed in vitro by real-time PCR and western blotting in SH- SY5Y cells; the binding sites of HIF-1α in VEGF and Netrin gene promoters were identified by luciferase reporter; the effect of fluoxetine on binding of HIF-1α with Netrin and VEGF promoters in hypoxia was observed by Chromatin Immunoprecipitation (Ch IP) Assay. We prove that HIF-1α regulates transcription of both VEGF and Netrin, and that in hypoxia fluoxetine up-regulates VEGF and Netrin expression via mediation of HIF-1α that binds to hypoxia-response element sites of VEGF and Netrin promoters. Our study indicates that HIF-1α may play an important role in the treatment of cerebral infarction through mediating the recovery of neurological function induced by fluoxetine, which provides theoretical basis for the development of gene therapeutic drugs targeting HIF-1α. [ABSTRACT FROM AUTHOR]

Background and Purpose: Cardiac fibrosis is a common feature of advanced coronary heart disease and is characteristic of heart disease. However, currently available drugs against cardiac fibrosis are still very limited. Here, we have assessed the role of isopropyl 3-(3,4-dihydroxyphenyl)-2-hydroxylpropanoate (IDHP), a new metabolite of Danshen Dripping Pills, in cardiac fibrosis mediated by the β-adrenoceptor agonist, isoprenaline, and its underlying mechanisms.Experimental Approach: Identification of IDHP was identified by mass spectrometry, and proton and carbon nuclear magnetic resonance spectra. Myocardial collagen was quantitatively assessed with Picrosirius Red staining. Expression of mRNA for collagen was evaluated with real-time PCR. Phosphorylated and total p38 MAPK, NADPH oxidase (NOX) and superoxide dismutase (SOD) were analysed by Western blot. Generation of reactive oxygen species (ROS) generation was evaluated by dihydroethidium (DHE) fluorescent staining. NOX2 was knocked down using specific siRNA.Key Results: IDHP attenuated β-adrenoceptor mediated cardiac fibrosis in vivo and inhibited isoprenaline-induced proliferation of neonatal rat cardiac fibroblasts (NRCFs) and collagen I synthesis in vitro. Phosphorylation of p38 MAPK, which is an important mediator in the pathogenesis of isoprenaline-induced cardiac fibrosis, was inhibited by IDHP. This inhibition of phospho-p38 by IDHP was dependent on decreased generation of ROS. These effects of IDHP were abolished in NRCFs treated with siRNA for NOX2.Conclusions and Implications: IDHP attenuated the cardiac fibrosis induced by isoprenaline through a NOX2/ROS/p38 pathway. These novel findings suggest that IDHP is a potential pharmacological candidate for the treatment of cardiac fibrosis, induced by β-adrenoceptor agonists. [ABSTRACT FROM AUTHOR]

Lignin-derived hierarchical porous carbon (LHPC) was prepared through a facile template-free method. Solidification of the lignin-KOH solution resulted in KOH crystalizing within lignin. The crystalized KOH particles in solid lignin acted both as template and activating agent in the heat-treatment process. The obtained LHPC, exhibiting a 3D network, consisted of macroporous cores, mesoporous channels, and micropores. The LHPC comprised 12.27 at % oxygen-containing groups, which resulted in pseudocapacitance. The LHPC displayed a capacitance of 165.0 F g−1 in 1 M H2SO4 at 0.05 A g−1, and the capacitance was still 123.5 F g−1 even at 10 A g−1. The LHPC also displayed excellent cycling stability with capacitance retention of 97.3 % after 5000 galvanostatic charge-discharge cycles. On account of the facile preparation of LHPC, this paper offers a facile alternative method for the preparation of hierarchical porous carbon for electrochemical energy storage devices. [ABSTRACT FROM AUTHOR]

Removal of imidacloprid and acetamiprid in tea infusions by microfiltration membrane using dead-end model was investigated in the present study. The results showed that microfiltration significantly promoted the removal of both pesticides ( P < 0.05) in tea infusions. Furthermore, the extent of removal was strongly influenced by the pore size of membrane, operational pressure and the concentrations of tea infusions. The initial concentration of imidacloprid and acetamiprid showed no significant effect on their removal rates. The maximum removal rates were 79.7% for imidacloprid and 81.9% acetamiprid. The changes in major chemical components of tea infusions after microfiltration were evaluated. The results indicated that microfiltration caused no considerable changes in total polyphenols and total free amino acids, and small but statistically significant losses (6.3-18.0%) of eight catechins and three methylxanthines when filtration volume reached to 200 mL. The present study validated the application of microfiltration as a potentially feasible and promising method for the removal of imidacloprid and acetamiprid residues from tea infusions. [ABSTRACT FROM AUTHOR]

BACKGROUND High moisture before harvest can cause sprouting of the wheat kernel, which is termed pre-harvest sprouting ( PHS). The aim of this study was to examine the variation in physicochemical properties of proteins in PHS-damaged (sprouted) hard red and white spring wheat genotypes. Specifically, protein content, enzyme activity and degradation of proteins were evaluated in sound and PHS-damaged wheat. RESULTS Protein contents of sprouted wheat samples were lower than that of non-sprouted samples; however, their differences were not significantly ( P > 0.05) correlated with sprouting score. Sodium dodecyl sulfate (SDS) buffer extractable proteins (EXP) and unextractable proteins ( UNP) were analyzed by high-performance size exclusion chromatography. PHS damage elevated endoprotease activity and consequently increased the degradation of polymeric UNP and free asparagine concentration in wheat samples. Free asparagine is known to be a precursor for formation of carcinogenic acrylamide during high heat treatment, such as baking bread. Free asparagine content had significant correlations ( P < 0.01) with sprouting score, endoprotease activity and protein degradation. CONCLUSIONS Genotypes with higher endoprotease activity tend to exhibit a larger degree of degradation of UNP and higher free asparagine concentration in sprouted wheat samples. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The lead dioxide electrode (PbO2) with Ti substrate and SnO2-Sb2O5 intermediate layer was doped by F- ion through the potentiostatic anode co-deposition method. The content of F in the coating can be controlled by adjusting deposition potential. The effect of F- doping on the composition, surface morphology and electrochemical properties of the PbO2 electrode was characterized by X-ray diffraction, scanning electron microscope, X-ray photoelectron spectroscopy and electrochemical measurement methods. The results have confirmed that the content of β-PbO2 increases with increasing that of F, and the doping can make the β-PbO2 grains become fine and the electrode surface become smooth; the specific surface areas and conductivity increase, and the initial potential of oxygen evolution shifts toward positive direction compared with the free-doped PbO2 electrode; the oxygen evolution potential increases with the increasing of the F-content in the PbO2 film electrode. The bulk electrolysis result demonstrated that the performances of the F-PbO2 electrode for anodic oxidation aniline have been improved to some extent. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The Ti/SnO2-Sb2O5/PbO2 electrode was prepared by electrodeposition method onto Ti substrate with SnO2-Sb2O5 interlayer. Microstructure information of SnO2-Sb2O5 interlayer and PbO2 coating was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Our study shows that the titanium substrate is completely covered by the SnO2-Sb2O5 solid solution interlayer and the interlayer combines the Ti substrate closely with the PbO2 coating. The electrochemical performance of the Ti/SnO2-Sb2O5/PbO2 electrode was studied by cyclic voltammogram (CV), electrochemical impedance spectroscopy (EIS) and accelerated life test. The results show the electrochemical activity, electrical conductivity and stability of Ti-substrate lead dioxide electrode are increased. The deactivation process of the Ti/SnO2-Sb2O5/PbO2 electrode was also studied by the EIS. The SnO2-Sb2O5 interlayer can effectively prevent the growth of a TiO2 insulating layer between the substrate and the PbO2 coating during the lifetime tests, thus maintain high activity of Ti/SnO2-Sb2O5/PbO2 electrode for 10 times longer than Ti/PbO2 electrode without interlayer. [ABSTRACT FROM AUTHOR]

Muscle fibrosis is a prominent pathological feature that directly causes muscle dysfunction in Duchenne muscular dystrophy (DMD). The DMD mouse models, mdx mice and mdx mice with haploinsufficiency of the utrophin gene (mdx/utrn(+/-) ), display progressive diaphragm fibrosis. We performed unrestrained whole-body plethysmography (WBP) in mdx and mdx/utrn(+/-) mice, and compared them with wild-type controls. Respiratory function gauged by respiratory frequency, tidal volume, minute volume, peak inspiratory flow, and peak expiratory flow was significantly impaired in the mdx mice. Consistent with more severe diaphragm fibrosis in the mdx/utrn(+/-) mice, respiratory impairment was worse than in mdx mice at 6 months. WBP is useful for monitoring in vivo respiratory function of mdx and mdx/utrn(+/-) mice, and it may serve as an outcome measurement for therapies that target diaphragm fibrosis. The mdx/utrn(+/-) mouse model may be better than the mdx model for testing antifibrotic therapies, especially at the severe stage. [ABSTRACT FROM AUTHOR]

In the crystal structure of the title compound, C(13)H(11)N(3)O(8)S(2), mol-ecules are linked by inter-molecular C-H⋯O hydrogen bonds into zigzag chains running parallel to the c axis. Centrosymmetrically related chains are further stabilized by aromatic π-π stacking inter-actions [centroid-centroid distance = 3.749 (3) Å] involving adjacent 4-nitro-benzene rings. Intra-molecular C-H⋯O hydrogen bonds are also present.