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Background Myocardial injury induced by sepsis is the most common cause of death. Topiroxostat has been found to have organ protective effects, but its role in septic shock-related cardiomyocyte damage is still unclear and needs further study. Material and methods An endotoxemic shock model in rats was constructed. After topiroxostat treatment, hemodynamic parameters, myocardial injury marker enzymes, oxidative stress, myocardial injury, and apoptosis were measured by polyphysiograph, enzyme-linked immunosorbent assay, hematoxylin and eosin staining, TUNEL staining, and western blot. During in vitro experiments, the effect of topiroxostat on cell vitality, oxidative stress, inflammatory factors, apoptosis-related markers, phosphorylated-p65 (p-p65) and p65 expressions were measured by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), flow cytometry, enzyme-linked immunosorbent assay, quantitative real-time polymerase chain reaction, and western blot. Results Topiroxostat improved myocardial dysfunction and superoxide dismutase activity while suppressing levels of creatine kinase, lactate dehydrogenase and malondialdehyde in serum of endotoxemic shock rats. Additionally, topiroxostat augmented dry-wet weight ratios of the hearts in rats. Meanwhile, topiroxostat was proved to alleviate interstitial edema and apoptosis in myocardial tissues of endotoxemic shock rats. During in vitro experiments, topiroxostat pretreatment elevated lipopolysaccharide (LPS)-induced H9c2 cell vitality, and alleviated oxidative stress and inflammation. Moreover, topiroxostat pretreatment downregulated apoptosis-related markers, p-p65, and p-p65/p65 levels in LPS-induced H9c2 cells. Conclusions Topiroxostat attenuated LPS-induced myocardial injury via repressing apoptosis and oxidative stress.

To improve hydrogen production performance of self-heating methanol steam reforming (MSR) microreactor, novel nickel foam with multiple microchannels was proposed as combustion reaction support. A wall temperature comparison of the methanol combustion microreactors with nickel foam catalyst support and particles catalyst support in the combustion reaction process was performed. According to the numerical simulation result of combustion reaction of nickel foam, the shape and size of multiple microchannels of nickel foam were determined. The laser processing was then used to fabricate the multiple microchannels of nickel foam. The experimental results show that the methanol combustion microreactor with nickel foam loaded with Pt catalyst exhibits similar wall temperature distribution with the methanol combustion microreactor with Pt/γ-Al2O3 particles reaction support. Compared with the nickel foam without a microchannel, the maximum temperature difference (ΔTmax) and the maximum temperature of nickel foam with multiple microchannels were decreased, respectively, by 57.8% and 33.8 °C when 1.1 mL/min methanol flow rate was used. Hydrogen production performance of the self-heating MSR microreactor using the nickel foam with multiple microchannels increased by about 21% when 430 °C reforming temperature and 4 mL/h methanol–water mixture flow rate were performed.

The distribution of archaeal isoprenoidal glycerol dialkyl glycerol tetraethers (isoGDGTs) has been increasingly used to characterize the archaeal community and to reconstruct palaeoenvironmental change. However, except for temperature, other environmental factors controlling the distribution of isoGDGTs remain to be explored. Environmental factors generally vary with depth along peat and soil profiles (PP and SP), which can provide unique opportunities to determine the impact of factors other than temperature on the distribution of archaeal ether lipids (AEL) in these settings. Here, we investigated the changes in AEL in two PPs and two red (ferralsol) SPs from southern China and determined the relationship of their distributions with peat and soil depth. The isoGDGT distribution in the two PPs and two SPs all show a significant dependence on depth. Crenarchaeol, which is likely to be produced by Thaumarchaeota, dominates in the upper parts of PPs and SPs, whereas GDGT-0 or isoGDGTs containing cyclopentyl moieties are the most abundant compounds in the deeper parts of these profiles. The change in the AEL distribution can be best characterized by %Cren (the proportion of crenarchaeol in total isoGDGTs) and MI (Methane Index), which are closely related to the water content in PPs and SPs. This suggests that %Cren and MI have potential for tracing the water content and, in turn, the redox conditions in paleosols and peats. The most remarkable differences in the AEL between PPs and SPs are the increased abundance of AEL, e.g., GDGT-5 (isoGDGTs with five cyclopentyl moieties), butanetriol dialkyl glycerol tetraethers (BDGTs), H-shaped isoGDGTs, methylated H-shaped isoGDGTs (Me-H-GDGTs) and the decreased abundance of hydroxylated isoGDGTs (OH-GDGTs) with depth in the two PPs, whereas these lipids are absent from the two SPs. This implies that the former group of lipids is likely derived from anaerobic archaea whereas OH-GDGTs and crenarchaeol are primarily of Thaumarchaeotal origin. The response of AEL to in situ environmental variables in the PPs and SPs reveals that the living archaea reside in the deep SPs and PPs and thus caution should be taken when applying these lipids to the high-resolution palaeoenvironmental reconstructions.

Hydroxylated isoprenoid glycerol dialkyl glycerol tetraethers (OH-GDGTs) were found having the potential to track past sea surface temperatures (SST), in analogy to the TEX86 – a paleothermometer based on isoprenoid GDGTs (iGDGTs). Especially in estuarine regions with high terrestrial input, the ring index of OH-GDGTs (RI-OH) was more robust to trace the summer SST than TEX86. In order to clarify the potential sources of sedimentary GDGTs and to further elucidate the potential of OH-GDGTs as SST proxy, we investigated the seasonal distribution of core OH-GDGTs and iGDGTs in the suspended particulate matter in a transition section in the Yangtze River Estuary. The concentrations of OH-GDGTs and iGDGTs were higher in the estuary than those in the lower Yangtze River, which suggested the OH-GDGTs and iGDGTs in estuarine sediment mainly came from marine autochthonous organisms, whereas the terrestrial contribution was relatively low. The higher content of OH-GDGTs and iGDGTs in summer than in winter indicated that sedimentary OH-GDGTs and iGDGTs mainly originated from the summer SPM deposition. In addition, the ratio of OH-GDGTs versus iGDGTs suggested that OH-GDGTs were relatively abundant in the upper water layer compared to iGDGTs, regardless of season. Furthermore, the distributions of iGDGTs and OH-GDGTs were found to be influenced by hydrodynamics. The increasing warm bias of iGDGT and OH-GDGT reconstructed temperatures with water depth suggested that either GDGTs in deeper waters derive mainly from surface water or GDGTs cyclization in deeper waters was influenced by reduced ammonium oxidation rates in response to the limited supply of ammonium and oxygen, especially in summer.

To replace the traditional electric heating mode and increase methanol steam reforming reaction performance in hydrogen production, methanol catalytic combustion was proposed as heat-supply mode for methanol steam reforming microreactor. In this study, the methanol catalytic combustion microreactor and self-thermal methanol steam reforming microreactor for hydrogen production were developed. Furthermore, the catalytic combustion reaction supports with different structures were designed. It was found that the developed self-thermal methanol steam reforming microreactor had better reaction performance. Compared with A-type, the △Tmax of C-type porous reaction support was decreased by 24.4 °C under 1.3 mL/min methanol injection rate. Moreover, methanol conversion and H2 flow rate of the self-thermal methanol steam reforming microreactor with C-type porous reaction support were increased by 15.2% under 10 mL/h methanol-water mixture injection rate and 340 °C self-thermal temperature. Meanwhile, the CO selectivity was decreased by 4.1%. This work provides a new structural design of the self-thermal methanol steam reforming microreactor for hydrogen production for the fuel cell.

Employing glutathione (HSG) as a protecting ligand, we have synthesized water-soluble and biocompatible Ag14(SG)12 nanoclusters (Ag14 NCs) of which the composition and structure are determined via high-resolution mass spectrometry, fingerprint spectroscopy and DFT calculations. Natural bond orbital (NBO) analysis on a basis of first-principles theoretical calculations demonstrates the donor–acceptor orbital overlaps and charge-transfer interactions between silver and the ligand HSG. Further, it is interestingly found that the fluorescence of Ag14 NCs can be largely enhanced at the presence of lysozyme distinguishing from other proteases which we have tested, revealing the feasibility of Ag14 NCs as chemosensing to identify lysozyme. Also found is that, the fluorescence on-state of the obtained Ag14NCs-Lys can be exclusively switched off at the addition of Hg2+ ions with an ultralow detection limit of ∼16.2 nM. This interesting finding reveals Ag14 NCs a versatile chemosensor to identify lysozyme from proteases and to detect mercury ions from various cations.

Here we report a successful synthesis of water-soluble 13-atoms gold clusters under the monolayer protection of binary thiolates, glutathione and penicillamine, under a molecular formula of Au 13 (SG) 5 (PA) 7 . This monolayer-protected cluster (MPC) finds decent stability and is demonstrated to possess an icosahedral geometry pertaining to structural accommodation in contrast to a planar bare Au 13 of local minima energy. Natural bond orbital (NBO) analysis depicts the interaction patterns between gold and the ligands, enlightening to understand the origin of enhanced stability of the Au 13 MPCs. Further, the water-soluble Au 13 MPCs are found to be a decent candidate for chemosensing and bioimaging.

BACKGROUND: Tissue injuries such as surgery and trauma are usually accompanied by simultaneous development of acute pain, which typically resolves along with tissue healing. However, in many cases, acute pain does not resolve despite proper tissue repair, rather, it transitions to chronic pain. In this study, we examined whether proliferator-activated receptor-gamma coactivator-1α (PGC-1α), a master regulator of mitochondria biogenesis, is implicated in pain chronification after burn injury in mice. METHODS: We used PGC-1α(+/+) and littermates PGC-1α(+/−) mice of both sex. Burn injury was induced on these mice. Hindpaw mechanical withdrawal thresholds and thermal withdrawal latency were examined. RESULTS: Hindpaw mechanical withdrawal thresholds and thermal withdrawal latencies were comparable at baseline between PGC-1α(+/−) and PGC-1α(+/+) mice. After burn injury, both PGC-1α(+/+) and PGC-1α(+/−) mice exhibited an initial dramatic decrease of withdrawal parameters at days 3 and 5 post-injury. While PGC-1α(+/+) mice fully recovered their withdrawal parameters to pre-injury levels by day 11 to 14, PGC-1α(+/−) mice failed to recover those parameters during the same time frame, regardless of sex. Moreover, we found that PGC-1α(+/−) mice resolved tissue inflammation in a similar fashion to PGC-1α(+/+) mice using a chemiluminescence-based reactive oxygen species imaging technique. CONCLUSIONS: Taken together, our data suggest that PGC-1α haploinsufficiency promotes pain chronification after burn injury.

We report the synthesis of penicillamine-protected Ag20 nanoclusters (NCs), with properties of high monodispersity, red fluorescence and water solubility. Full characterization of the Ag20 NCs is addressed, along with first-principles optimization calculations, revealing the chemical composition and structure of the as-prepared Ag NCs within a molecular formula [Ag20(DPA)18-H]−. Moreover, natural bond orbital (NBO) analysis demonstrates the charge-transfer interactions between the ligand and Ag atoms, and helps in understanding the origins of fluorescence of Ag20 NCs related to the ligand-to-metal charge transfer (LMCT) mechanism. Further, fluorescence chemosensing of the Ag20 NCs is demonstrated for tracing copper ions with high sensitivity and selectivity in aqueous solution.

To achieve a better understanding of Holocene climate change in the monsoon regions of China, we investigated the molecular distributions and carbon and hydrogen isotope compositions delta C-13 and delta D values) of long-chain n-alkanes in a peat core from the Shiwangutian SWGT) peatland, south China over the last 9 ka. By comparisons with other climate records, we found that the delta C-13 values of the long-chain n-alkanes can be a proxy for humidity, while the dD values of the long-chain n-alkanes primarily recorded the moisture source dD signal during 9-1.8 ka BP and responded to the dry climate during 1.8-0.3 ka BP. Together with the average chain length ACL) and the carbon preference index CPI) data, the climate evolution over last 9 ka in the SWGT peatland can be divided into three stages. During the first stage 9-5 ka BP), the delta C-13 values were depleted and CPI and Paq values were low, while ACL values were high. They reveal a period of warm and wet climate, which is regarded as the Holocene optimum. The second stage 5-1.8 ka BP) witnessed a shift to relatively cool and dry climate, as indicated by the more positive delta C-13 values and lower ACL values. During the third stage 1.8-0.3 ka BP), the delta C-13, delta D, CPI and Paq values showed marked increase and ACL values varied greatly, implying an abrupt change to cold and dry conditions. This climate pattern corresponds to the broad decline in Asian monsoon intensity through the latter part of the Holocene. Our results do not support a later Holocene optimum in south China as suggested by previous studies., Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe, 543

Development of Raman spectroscopy, profiting from surface-enhanced Raman scattering and tip-enhanced Raman scattering techniques, has inspired extensive research interest for trace analysis and dynamic measurements up to single-molecule level. For another, Raman spectroscopy has also been recognized of significance in solving some important issues relating to molecule aggregates in chemistry and biology, owing to the capability of non-destructive detection and high-resolution fingerprints by which molecules and their aggregates can be identified. Herein, we summarize the recent progress of Raman spectroscopy in probing single molecules and molecular aggregates and block out a future prospective of Raman spectroscopy applied in cluster science. Copyright © 2015 John Wiley & Sons, Ltd.

The methylation index (MBT or MBT′) of branched glycerol dialkyl glycerol tetraethers (brGDGTs) in soils along altitudinal transects of some mountains, e.g. Mount (Mt.) Shennongjia and Mt. Gongga, exhibited no correlation with altitude or mean annual air temperature (MAT) alone. However, a significant correlation between MBT′, cyclization ratio (CBT) of brGDGTs and MAT for each transect could still be found. To investigate the reason, we reanalyzed the brGDGTs in soils from Mt. Shennongjia using an improved liquid chromatography method and examined whether the newly described 6-methyl brGDGTs were the main cause of the large scatter in the correlation between MBT′ and MAT. In contrast to MBT′, the MBT′5ME, based on 5-methyl brGDGTs alone, correlated significantly with MAT (R2 0.89, p

Ligand-protected metal nanoclusters (NCs) having hydrodynamic diameters and fluorescent properties have reasonable potential for ion detection and bio-imaging applications by taking advantage of their smaller sizes and degradability as compared with larger nanoparticles. By controlling the pH value, here we have synthesized a fluorescent silver nanocluster, Ag–glutathione, which is found to be a versatile chemosensor operative for the detection of both manganese (Mn2+) and iodine (I−) ions. Mn2+ and I− are further distinguished by the ratiometric absorption spectrometry method. Care was taken for sufficient spectral analyses, based upon which we have fully demonstrated the chemosensing mechanisms of Ag@glutathione (Ag@SG) NCs applied in ion detection. Having expounded this issue, we further investigated the potential application of Ag@SG NCs in bio-imaging. It is interesting to find that the as-prepared Ag@SG NCs are nontoxic and available for fluorescence imaging of MCF-7 cells, with on/off alternation of fluorescence emission in the presence of Mn2+ or I− ions. The low cytotoxicity, good penetrability and on/off fluorescence property of Ag@SG NCs in MCF-7 cells suggest promising biological applications.

To assess the source of glycerol dialkyl glycerol tetraethers (GDGTs) and their usefulness as proxies for terrestrial organic matter inputs and temperature in the Yellow River-dominated margin, we measured isoprenoid and branched GDGT concentrations in surface sediments along a lower Yellow River-estuary–coast transect. Branched GDGTs dominated over isoprenoid GDGTs in the riverbed sediments and had similar compositions from river to coast. In contrast, isoprenoid GDGTs displayed an increasing abundance and a decreasing GDGT-0 to crenarchaeol ratio (1.6 to 0.6) toward the sea. Such distribution patterns of GDGTs, combined with the result from a principal component analysis (PCA), confirmed the different origin of branched and isoprenoid GDGTs with branched GDGTs being primarily from soil erosion of the Chinese loess plateau (CLP) whereas, in addition to allochthonous terrestrial inputs, aquatic Thaumarchaeota partially contributes to the isoprenoid GDGT pool in estuarine and coastal areas. The branched GDGT-derived temperature (avg. 11 °C) is consistent with the annual mean air temperature (MAT) of the CLP in the middle river basin, a major source region for the Yellow River sediments, whereas the isoprenoid-derived temperature (12.7 to 28.4 °C) deviated widely from the annual mean temperature in the study region. Application of a binary mixing model based on δ13C, the branched and isoprenoid tetraether (BIT) index and branched GDGT concentrations showed consistent decreases in the relative amount of terrestrial organic carbon toward the sea, but estimates from the latter two proxies were lower than those from the δ13C.

Isoprenoid and branched glycerol dialkanol diethers (iGDDs and bGDDs) have recently been found in marine and peat deposits, whereas their distributions and sources in soils are undetermined. We present the distributional characteristics of GDDs, as well as their corresponding glycerol dialkyl glycerol tetraethers (GDGTs), in Chinese surface soils and a loess–paleosol sequence (LPS) in northwest China to study the source of GDDs and their relationship with GDGTs. The distributions of iGDDs and bGDDs were comparable with those of the corresponding GDGTs, with a dominance of iGDGTs over bGDGTs in alkaline soil and the opposite in acid soil. By extension, the GDD- and GDGT-based BIT indices exhibited the same trends in both surface soils and the LPS. The fractional abundances of individual iGDDs and bGDDs were also similar to those of the corresponding GDGTs, resulting in similar cyclization patterns for iGDGTs and iGDDs, and similar methylation indices for bGDGTs and bGDDs. These similarities suggest that bGDDs and iGDDs may share a common biological source with the corresponding GDGTs. In the LPS, the GDGT/(GDGT + GDD) ratio decreased exponentially with depth, fitting a first order kinetic degradation (or more specifically, transformation) model that has commonly been applied to other lipid classes; this is strong evidence for a diagenetic origin for GDDs. Although our results do not exclude production of GDDs directly by microorganisms, they do suggest that the GDDs may be the degradation products of GDGTs.

The temperature gradient along the altitude transect of Mt. Jianfengling provides a good opportunity to establish and evaluate the microbial lipid-based environmental proxies. The soils collected from 14 different altitudes of Mt. Jianfengling contain abundant microbial fatty acids and fatty alcohols, including iso/anteiso fatty acids (i/aC12:0-i/aC19:0), 10-Me-C16:0 fatty acid, iso/anteiso fatty alcohols (i/aC13-iC26), 10-Me-C16:0 fatty alcohol and unsaturated fatty alcohols, which can indicate a strong microbial activity in the Jianfengling soils. The branched and unsaturated fatty alcohols can be only detected when saponification is performed, implying that these lipids are present as the constituents of bacterial wax esters in the soils. The ratio of aC15/iC15 fatty acids is positively correlated with altitude, suggesting that the decrease in temperature can induce the increase in the relative abundance of anteiso C15 fatty acid. In contrast, the ratio of aC15/iC15 fatty alcohols and of aC15/nC15 fatty alcohols both decrease with increased altitude or decreased temperature. Similarly, the ratio of nC18:1/nC18:0 fatty alcohols also decreases with decreased temperature, which is opposite to the previous observation that unsaturation of fatty acids in microorganism increases in response to decreased temperature. Besides, the average chain length (ACL) of long chain fatty alcohols (C22–C30) from leaf waxes and carbon preference index (CPI) of all n-fatty alcohols are also significantly correlated with altitude or mean annual temperature, demonstrating their potential for paleoclimate reconstruction. The correlation of microbial fatty acids and alcohols as well as ACL and CPI of plant wax-derived fatty alcohols with altitude may provide novel ways to reconstruct paleotemperature and paleoaltimetry.

Glycerol dialkyl glycerol tetraethers (GDGTs) and bulk organic geochemical parameters were examined for a short core from the Bohai Sea, a Yellow River-dominated continental margin. A three end member mixing model using branched/isoprenoid tetraethers (BIT) index, δ13C and C/N shows that the average fractions of soil, marine and plant organic matter (OM) during the period of 1933–2011 are 67.7% (38–92%), 26.1% (0–58%) and 6.2% (0–23%), respectively. Abrupt changes of sedimentary OM compositions around 1953, 1976 and 1996 are synchronous with the Yellow River mouth relocations. The BIT index values (0.33–0.80) present a stronger correlation with crenarchaeol abundance (R2 = 0.88) than branched GDGTs abundance (R2 = 0.27), suggesting that variations of marine Thaumarchaeota abundance rather than soil OM inputs is the first order factor controlling the BIT index values, although this proxy has been widely used for soil OM. The comparison between the BIT index, nutrient status and historical Yellow River sediment load indicates that the high sensitivity of the BIT index to the Yellow River channel shifts cannot be explained by a nutrient stimulation mechanism, but instead is likely caused by the restriction of Thaumarchaeota growth in highly turbid water due to the enormous sediment inputs from Yellow River. Our study demonstrates that local conditions should be considered when applying the BIT index as an environmental proxy.

Glycerol dialky glycerol tetraethers (GDGTs) are membrane lipids of archaea and some unknown bacte-ria. These GDGTs have been demonstrated to respond to temperature and pH variations based on global in-vestigations on marine sediments and modern surface soils (Kim et al., 2008; Weijers et al., 2007). On this point, environmental proxies, TEX