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BACKGROUND AND PURPOSE Luminal glucose enhances intestinal Ca2+ absorption through apical Cav 1.3 channels necessary for GLUT2-mediated glucose absorption. As these reciprocal mechanisms are not well understood, we investigated the regulatory mechanisms of intestinal [Ca2+ ]cyt and SGLT1-mediated Na+ -glucose co-transports. EXPERIMENTAL APPROACH Glucose absorption and channel expression were examined in mouse upper jejunal epithelium using an Ussing chamber, immunocytochemistry and Ca2+ and Na+ imaging in single intestinal epithelial cells. KEY RESULTS Glucose induced jejunal Isc via Na+ -glucose cotransporter 1 (SGLT1) operated more efficiently in the presence of extracellular Ca2+ . A crosstalk between luminal Ca2+ entry via plasma Cav 1.3 channels and the ER Ca2+ release through ryanodine receptor (RYR) activation in small intestinal epithelial cell (IEC) or Ca2+ -induced Ca2+ release (CICR) mechanism was involve in Ca2+ -mediated jejunal glucose absorption. The ER Ca2+ release through RyR triggered basolateral Ca2+ entry or store-operated Ca2+ entry (SOCE) mechanism and the subsequent Ca2+ entry via Na+ /Ca2+ exchanger 1 (NCX1) were found to be critical in Na+ -glucose cotransporter-mediated glucose absorption. Blocking RyR, SOCE and NCX1 inhibited glucose induced [Na+ ]cyt and [Ca2+ ]cyt in single IEC and protein expression and co-localization of STIM1/Orai1, RyR1 and NCX1 were detected in IEC and jejunal mucosa. CONCLUSION AND IMPLICATIONS Luminal Ca2+ influx through Cav 1.3 triggers the CICR through RyR1 to deplete the ER Ca2+ , which induces the basolateral STIM1/Orai1-mediated SOCE mechanism and the subsequent Ca2+ entry via NCX1 to regulate intestinal glucose uptake via Ca2+ signalling. Targeting these mechanisms in IEC may help to modulate blood glucose and sodium in the metabolic disease.

A series of iron supported on Zr-intercalated clay composite catalysts with mesoporous structure, a high specific surface area, and high thermal stability were successfully synthesized (named Fe/Zr-Lap catalysts) and tested for H2S selective oxidation. The structural characteristics and physicochemical properties of the catalysts were investigated using various methods. The iron species existed mainly as isolated Fe3+ and polymeric (FeO)n species in an octahedral coordination. All of the Fe/Zr-Lap catalysts exhibited excellent catalytic activity at relatively low temperatures (120–200 °C). The 8% Fe/Zr-Lap catalyst presented the best catalytic performance at 180 °C. It is likely that highly dispersed iron species, abundant chemically adsorbed oxygen vacancies, synergistic effect of iron and zirconium species, and improved reducibility played important roles in the reaction. Besides, the reaction and deactivation mechanisms were also proposed.

Although capsaicin has been studied extensively as an activator of the transient receptor potential vanilloid cation channel subtype 1 (TRPV1) channels in sensory neurons, little is known about its TRPV1-independent actions in gastrointestinal health and disease. Here, we aimed to investigate the pharmacological actions of capsaicin as a food additive and medication on intestinal ion transporters in mouse models of ulcerative colitis (UC). The short-circuit current (I

MnxAlO mixed oxide catalysts derived from MnxAl-LDHs were prepared and tested for acetone catalytic oxidation. Detailed results indicated that the surface intrinsic and formed oxygen vacancies can induce the Mn-O bond of structural unit [MnO6] weakened. Subsequently, it can improve the redox properties of catalysts, and enhance the capacity of gaseous oxygen species dissociation and adsorption. Among them, Mn3AlO catalyst displayed the best catalytic performance for acetone oxidation (T90 = 164 °C) with the production of low amount of byproduct ( 99%) producted. Additionally, the Mn3AlO catalyst can proceed consecutively for 12 h reaction without notable deactivation. Furthermore, in situ DRIFT and theoretical calculations methods was adopted to explore the reaction mechanism. And η1(O)(ads) (adsorption mode of acetone), CH2=C(CH3)=O(ads), O*, CH3CHO*, CH2O* and COO(ads) were considered as the main intermediate species and/or transient state during the reaction process. It was revealed that the acetone and oxygen molecules were activated by the dehydrogenation (α-H abstraction) and dissociation process over Mn3AlO catalyst, respectively, and then the intermediate specie, CH2 C(CH3) O and O*, were produced, which was followed by the breaking of C C bonds to produce the CH3CHO* and CH2O* species. Finally, these species were attacked by dissociated oxygen (O*) and therefore further dehydrogenation occurred, form H2O and CO2 via the COO adsorbed species. Particularly, C C bond breaking was the main rate determining step for acetone oxidation.

Deepwater exploration has been developed for more than 40 years since 1975; generally, its exploration history can be divided into the beginning stage (1975–1984), the early stage (1985–1995) and the rapid development stage (1996-now). Currently, deepwater areas have become the hotspot of global oil and gas exploration, and they are also one of the most important fields of oil and gas increase in reserves and production all over the world. In 40 years, global deepwater oil and gas discoveries are mainly distributed along five deepwater basin groups which are characterized by “three vertical and two horizontal” groups: (1) In deepwater basins of the Atlantic Ocean, giant discoveries of oil are mainly concentrated in Brazil, West Africa and the Gulf of Mexico, and significant discoveries of natural gas are mainly on the west coast of Norway in the northern part of the Atlantic Ocean; (2) In deepwater basins of the East African continental margin, a group of giant gas fields has been found in the Rovuma Basin and Tanzania Basin; (3) In deepwater basins of the West Pacific Ocean, giant discoveries of oil and gas are mainly concentrated in the South China Sea and Southeast Asian waters; (4) The deepwater basins of the Neo-Tethys Region are rich in gas, and the most important gas discoveries are mainly distributed in the northwest shelf of Australia and the eastern Mediterranean; and (5) In deepwater basins around the Arctic Pole, major discoveries of oil and gas have been only found in deepwater areas of the Barents sea. Global deepwater oil resources are mainly concentrated in the middle and south sections of the Atlantic Ocean. Deepwater gas resources are relatively widely spread and mainly distributed in the northern part of Atlantic Ocean deepwater basins, the deepwater basins of East Africa, the deepwater basins of the Neo-Tethys region and the deepwater basins around the Arctic Pole. There will be six domains for future oil-gas exploration of global deepwater basins which are characterized by “two old and four new” domains; specifically, “two old” domains referring to the Atlantic offshore deepwater basins and offshore deepwater basins of the Neo-Tethys structural domain, where the exploration degree is relatively high, and the potential is still great. While the “four new” domains stand for pre-salt and ultra deepwater basin formations, offshore deepwater basins surrounding the North Pole area and West Pacific offshore deepwater basins and the new fields will be the main fields of deepwater oil and gas exploration in the future. Keywords: Deepwater, Giant discoveries of oil and gas, Brazil, West Africa, Gulf of Mexico, East Africa, Northwest shelf of Australia, Eastern mediterranean, New field

Herein, we explore a new carbon source for preparation of carbon quantum dots (CQDs) with controllable composition using a porous organic polymer (POP) derived porous carbon via a nitric acid oxidation method. The POP used for the preparation of CQDs was synthesized by mechanochemical Friedel–Crafts alkylation under solvent free conditions. Using the as-prepared CQDs, we develop a simple and effective electrochemiluminescence (ECL) detection method for dopamine (DA) using a CQD/chitosan–graphene composite modified glassy carbon electrode (GCE). Both the electrochemical and ECL behaviors were studied in detail with ammonium persulfate as a coreactant. The complementary structure and synergistic function of the composite give the ECL sensor special properties. Apart from the high stability, it also presents good repeatability and high sensitivity to DA with a wide linear range from 0.06 to 1.6 μM. And a satisfactory detection limit of 0.028 μM (S/N = 3) was achieved for the prepared sensor. Furthermore, the ECL also shows high selectivity toward DA with an excellent interference resistance ability at a high concentration ratio of 100 (Cinterference : CDA = 100). In addition, the ECL sensor was successfully applied for effective detection and quantitative analysis of the actual dopamine in human body fluids for disease diagnosis and pathological studies.

In China, gastric cancer (GC) ranks first in the incidence of all malignant tumors. With high recurrence and distant metastasis, GC has caused considerable mortalities. LncRNA long intergenic non-protein-coding RNA 668 (LINC00668) has been reported to be upregulated in GC cells and predict poor prognosis of GC patients. However, the mechanism of LINC00668 has not been fully investigated in GC. This study aimed to investigate the role of LINC00668 in GC. We found that LINC00668 level was upregulated in GC tissue and cells and predicted poor prognosis. Functionally, LINC00668 knockdown suppressed GC cell migration and invasion. Additionally, LINC00668 knockdown inhibited epithelial to mesenchymal transition (EMT) process. PKN2 exerts similar effects with LINC00668 in GC cells. LINC00668 knockdown suppressed tumor growth and metastasis in vivo. Mechanistically, HuR was predicted to bind with LINC00668 and protein kinase N2 (PKN2). RNA pull-down assays validated the binding between HuR and LINC00668 (or PKN2). Moreover, either silencing of LINC00668 or HuR could decrease PKN2 mRNA stability or reduce PKN2 mRNA and protein levels. Furthermore, PKN2 expression was positively correlated with LINC00668 expression and HuR expression in GC tissues, and HuR expression was positively associated with LINC00668 expression in GC tissues. Finally, rescue assays confirmed that the suppressive effect of LINC00668 silencing on cell migration, invasion, and EMT process was reversed by PKN2 overexpression or HuR upregulation. In conclusion, LINC00668 cooperated with HuR-dependent upregulation of PKN2 to facilitate gastric cancer metastasis, which may provide a potential novel insight for GC treatment.

A series of La1−xCexFeO3 perovskite catalysts were synthesized using a citrate sol-gel method and examined for H2S selective catalytic oxidation reaction. It was demonstrated that the catalysts exhibited prominent catalytic activity, outstanding sulfur selectivity (nearly 100%) and particularly low apparent activation energy. Remarkably, it can proceed consecutively for 70 h without notable deactivation. Moreover, Ce and Fe were mainly existed in the form of LaCeFeO3 perovskite-type oxides as well as Ce-Fe solid solution. Significantly, catalysts reducibility was improved greatly due to the strongly Ce-Fe synergetic effect. More importantly, a proper substitution of Ce can enhance surface basic properties and facilitate the formation of oxygen vacancies on the catalyst surface, and hence improve H2S adsorbability and lattice oxygen mobility, respectively. It cooperating with the improved reducibility jointly contributed to the excellent catalytic performance. Furthermore, the reaction obeyed a redox mechanism and the catalyst deactivation was due mainly to the formation of sulfate species. Additionally, the added water can lead to the establishment of the reverse Claus reaction, causing the decrease of catalytic performance.

Luminal glucose enhances intestinal CaGlucose absorption and channel expression were examined in mouse upper jejunal epithelium using an Ussing chamber, immunocytochemistry and CaGlucose induced jejunal ILuminal Ca

The cytosolic calcium ([Ca2+]cyt) is one of the most important cell signaling that can modulate gastrointestinal (GI) epithelial secretion and promote GI mucosal wound repair. The GI mucosal bicarbonate secretion is the main mechanism of mucosal protection. Our research team has been working in this field and provided solid evidence for the important role of Ca2+ signaling in the regulation of GI epithelial secretion and the underlying molecular mechanisms. In this review, we attempt to systemically review the current status of our knowledge on the role of Ca2+ signaling in the regulation of intestinal bicarbonate secretion and in the upper GI epithelial protection. We expect that novel targets could be identified for drug development to better protect GI mucosa and treat mucosal injury with the advance in this filed.

// Xin Yang 1 , Yanjun Guo 1 , Jialin He 1 , Fenglian Zhang 1 , Xuemei Sun 1 , Shiming Yang 1 and Hui Dong 1, 2 1 Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, P.R. China 2 Division of Gastroenterology, Department of Medicine, School of Medicine, University of California, San Diego, California, USA Correspondence to: Hui Dong, email: h_uidong@163.com Keywords: estrogen, estrogen receptors, HCO 3 - secretion, Cl - secretion Received: April 15, 2017 Accepted: May 22, 2017 Published: May 31, 2017 ABSTRACT Gastrointestinal (GI) epithelial ion transport is physiologically important in many aspects of humans, such as in maintaining fluid balance of whole body, and also plays a role in the development and progression of common GI disease. Estrogen and estrogen receptors have been shown to modulate the activity of epithelial ion secretion in GI tract. This review aims to address the current state of knowledge about the role of estrogen and estrogen receptors in modulation of GI epithelial secretion and to elucidate the underlying mechanisms. We highlight the recent findings regarding the importance of estrogen and estrogen receptors in GI epithelia protection and body fluid balance by modulation of gastrointestinal epithelial HCO 3 - and Cl - secretion, especially current information about the regulatory mechanisms of duodenal HCO 3 - secretion based on our study in this field. Since there are no reviews on this topic but only few papers to address the main issues, we hope to timely provide new perspectives for the association between estrogen and GI disease.

An improved ammonia-based desulfurization technology was proposed, in which the produced excess NH4HSO3 was concentrated by using the heat from the Claus tail gas and then SO2 was recovered by decomposing the concentrated NH4HSO3 in the Claus furnace. Furthermore, the process was modeled and simulated using the commercial software Aspen Plus. The characteristics of the ammonia-based desulfurization model were validated and compared with experimental results. Moreover, the water balance in the system was maintained, therefore, no extra water was required. Under the water balance condition, the SO2 removal performance in the system was predicted with various operating conditions. The model exhibited a reliable prediction of the desulfurization performance of the innovative process, which will be favorable for actual industrial application.

The effects of low pressure and abnormally low pressure on reservoir diagenesis and physical property of the Paleocene in southern part of Western Sag of Liaohe Depression, Bohai Bay Basin have been analyzed using large amounts of pressure, physical property and formation testing data. When formation pressure is low or abnormally low, the pore fluid has lower pressure, the overburden litho-static pressure is largely born by the sandstone framework, sometimes over compaction occurs, leading to densification of reservoir and stronger mechanical compaction; residual formation pressure has a negative correlation with carbonate cement content, low pressure or abnormally low pressure tight sandstone formations have higher carbonate cement content than sandstone formations with hydrostatic pressure or weak overpressure; pore fluid in sandstones with low pressure or abnormally low pressure has higher Si4+, conducive to the siliceous cementation; when dissolution happens, reservoirs with low pressure or abnormally low pressure, poor in original physical properties, are not favorable for the injection of dissolution fluid and the expulsion of dissolution products, so they have weaker dissolution. In summary, reservoirs with low pressure or abnormally low pressure have poorer physical properties. Key words: abnormally low pressure, diagenesis, reservoir physical property, tight sandstone, Western Sag, Liaohe Depression

Simultaneous recovery of hydrogen and sulfur resources from acidic gas hydrogen sulfide (H2S), whose content may reach 20–100 % after hydrodesulfurization in oil refineries, is increasingly attractive. Nowadays, the widespread utilization of H2S decomposition technology is mainly restricted by the low hydrogen and sulfur yield, i.e. 20 % at 800 °C. In this work, for the first time a novel non-sulfide based LaFexAl12-xO19 hexaaluminate catalysts was used for high (50 %) hydrogen yield at 800 °C. At the same time, the active phases and reaction mechanism were confirmed by various characterization techniques. The XRD, Raman, XPS, Mossbauer and XAFS results verified that the Fe species in the hexaaluminate structure, especially octahedral-coordinated Fe3+, served as the main active phases. The reaction routes/mechanism for H2S decomposition were also verified by density functional theory (DFT) method. H2S was firstly adsorbed on the active sites and then completed the decomposition by direct dehydrogenation mechanism. Briefly, current study has minimized the challenges for H2S decomposition at industrial scale. It is anticipated that our findings will offer potential application of H2S decomposing technology.

BACKGROUND AND PURPOSE: As little is known about the effect of caffeine, one of the most widely consumed substances worldwide, on intestinal function, we aimed to study its action on intestinal anion secretion and the underlying molecular mechanisms. EXPERIMENTAL APPROACH: Anion secretion and channel expression were examined in mouse duodenal epithelium by Ussing chambers and immunocytochemistry. Ca(2+) imaging was also performed in intestinal epithelial cells (IECs). KEY RESULTS: Caffeine (10 mM) markedly increased mouse duodenal short‐circuit current (I (sc)), which was attenuated by a removal of either Cl(−) or HCO(3) (−), Ca(2+)‐free serosal solutions and selective blockers of store‐operated Ca(2+) channels (SOC/Ca(2+) release‐activated Ca(2+) channels), and knockdown of Orai1 channels on the serosal side of duodenal tissues. Caffeine induced SOC entry in IEC, which was inhibited by ruthenium red and selective blockers of SOC. Caffeine‐stimulated duodenal I (sc) was inhibited by the endoplasmic reticulum Ca(2+) chelator (N,N,N′,N′‐tetrakis(2‐pyridylmethyl)ethylenediamine), selective blockers (ruthenium red and dantrolene) of ryanodine receptors (RyR), and of Ca(2+)‐activated Cl(−) channels (niflumic acid and T16A). There was synergism between cAMP and Ca(2+) signalling, in which cAMP/PKA promoted caffeine/Ca(2+)‐mediated anion secretion. Expression of STIM1 and Orai1 was detected in mouse duodenal mucosa and human IECs. The Orai1 proteins were primarily co‐located with the basolateral marker Na(+), K(+)‐ATPase. CONCLUSIONS AND IMPLICATIONS: Caffeine stimulated intestinal anion secretion mainly through the RyR/Orai1/Ca(2+) signalling pathway. There is synergism between cAMP/PKA and caffeine/Ca(2+)‐mediated anion secretion. Our findings suggest that a caffeine‐mediated RyR/Orai1/Ca(2+) pathway could provide novel potential drug targets to control intestinal anion secretion.

// Xin Yang 1, * , Guorong Wen 2, * , Biguang Tuo 2 , Fenglian Zhang 1 , Hanxing Wan 1 , Jialin He 1 , Shiming Yang 2 and Hui Dong 1, 3 1 Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China 2 Department of Gastroenterology, Affiliated Hospital, Zunyi Medical College, and Digestive Disease Institute of Guizhou Province, Zunyi 563003, China 3 Department of Medicine, School of Medicine, University of California, San Diego, CA 92093, USA * These authors contributed equally to this work Correspondence to: Hui Dong, email: h_uidong@163.com Shiming Yang, email: 13228686589@163.com Keywords: carbachol; Ca 2+ signaling; SOCE; duodenal epithelial ion transports Received: October 19, 2017 Accepted: December 01, 2017 Published: December 11, 2017 ABSTRACT Background and Purpose: Although Ca 2+ signaling may stimulate small intestinal ion secretion, little is known about its critical role and the molecular mechanisms of Ca 2+ -mediated biological action. Key Results: Activation of muscarinic receptors by carbachol(CCh) stimulated mouse duodenal I sc , which was significantly inhibited in Ca 2+ -free serosal solution and by several selective store-operated Ca 2+ channels(SOC) blockers added to the serosal side of duodenal tissues. Furthermore, we found that CRAC/Orai channels may represent the molecular candidate of SOC in intestinal epithelium. CCh increased intracellular Ca 2+ but not cAMP, and Ca 2+ signaling mediated duodenal Cl - and HCO 3 - secretion in wild type mice but not in CFTR knockout mice. CCh induced duodenal ion secretion and stimulated PI3K/Akt activity in duodenal epithelium, all of which were inhibited by selective PI3K inhibitors with different structures. CCh-induced Ca 2+ signaling also stimulated the phosphorylation of CFTR proteins and their trafficking to the plasma membrane of duodenal epithelial cells, which were inhibited again by selective PI3K inhibitors. Materials and Methods: Functional, biochemical and morphological experiments were performed to examine ion secretion, PI3K/Akt and CFTR activity of mouse duodenal epithelium. Ca 2+ imaging was performed on HT-29 cells. Conclusions and Implications: Ca 2+ signaling plays a critical role in intestinal ion secretion via CRAC/Orai-mediated SOCE mechanism on the serosal side of epithelium. We also demonstrated the molecular mechanisms of Ca 2+ signaling in CFTR-mediated secretion via novel PI3K/Akt pathway. Our findings suggest new perspectives for drug targets to protect the upper GI tract and control liquid homeostasis in the small intestine.

The cytosolic calcium ([Ca2+]cyt) is one of the most important cell signaling that can modulate gastrointestinal (GI) epithelial secretion and promote GI mucosal wound repair. The GI mucosal bicarbonate secretion is the main mechanism of mucosal protection. Our research team has been working in this field and provided solid evidence for the important role of Ca2+ signaling in the regulation of GI epithelial secretion and the underlying molecular mechanisms. In this review, we attempt to systemically review the current status of our knowledge on the role of Ca2+ signaling in the regulation of intestinal bicarbonate secretion and in the upper GI epithelial protection. We expect that novel targets could be identified for drug development to better protect GI mucosa and treat mucosal injury with the advance in this filed.

The thermal problem of plate slides against symmetrically located contacting pads is investigated. The aim is to find out the influences of plate thickness, moving speed, and convection on the temperature field of the plate. Proper models and computing methods for specific situations can be determined based on these analyses. Finite element method of moving heat input is used to calculate the temperature field which is validated by comparing with some existing analytical solutions. The results show that the characteristic time for the steady state of temperature can be approximated exponentially as a function of moving speed. If the plate is thinner than the critical thickness, the surface temperature is increased significantly, which means that the temperature field is very sensitive to the plate thickness in this situation. The increasing moving speed increases the peak surface temperature almost linearly, and the convection outside of the contact area can decrease the peak surface temperature significantly if the heat sources move slowly, while it hardly affects the peak surface temperature if the heat sources move fast. Based on these results, the criterion of choosing a model and computing methods for studying the temperature fields in the similar structures is established.