Activation Of Cl Research Articles

Migration and transformation of lead species over CaO surface in municipal solid waste incineration fly Ash: A DFT study

Heavy metal pollutants generated from municipal solid waste (MSW) incineration are mainly concentrated in the fly ash, among which lead species have received considerable attention due to their high content and biotoxicity. CaO is an active component in fly ash to adsorb heavy metal species. In this study, based on density functional theory (DFT) calculations, the migration and transformation mechanisms of lead species over the CaO (100) surface were investigated by calculating the adsorption configurations, energies, and electronic structures, etc. The results indicate that the adsorption of lead species over the CaO (100) surface is dominated by chemisorption, and PbCl2 molecule exhibits a stronger affinity to the CaO surface than Pb0. The dissociation of HCl molecule on the CaO (100) surface facilitates the adsorption and chemical reactivity of lead species. The chlorination of Pb0 to PbCl2 is a two-stage route. In the first stage, two HCl molecules are exothermically adsorbed on the surface without an energy barrier, and Pb0 is directly bonded to the active Cl atom, which is controlled by the Eley-Rideal mechanism. In the second stage, PbCl intermediate bonds with another Cl atom over the surface to form the PbCl2 molecule, following the Langmuir-Hinshelwood mechanism, which is also the rate-determining step. Compared with the homogeneous chlorination, CaO catalyzes the heterogeneous process to greatly reduce the oxidation energy barrier and promotes the formation of PbCl2. Consequently, CaO is able to accelerate the lead enrichment in fly ash, which is favorable for lead species purification.

γ-Fe2O3 decorated attapulgite composite modified with CuCl2 as magnetically separable sorbents for Hg0 removal from coal combustion flue gas

To remove Hg0 from coal combustion flue gas efficiently and economically, a magnetically recoverable sorbent fabricated by incorporating γ-Fe2O3 into attapulgite and subsequently being loaded with CuCl2 was developed and employed for Hg0 removal in a fixed-bed reactor. Results indicated that 0.05CuFA could eliminate more than 88% of Hg0 from the SFG with HCl or not at 150 °C under GHSV of 2 × 106h−1. The surface O* and Cl* species were responsible for Hg0 oxidation, and the products of mercury were mainly HgO and HgCl2. O2 contributed to Hg0 removal by regenerating the consumed O* and re-oxidizing the Cu+ and Fe2+. NO and SO2 both insignificantly affected Hg0 removal over 0.05CuFA, because CuCl2 could hinder the reaction of NO and SO2 with the surface-active sites, leading to no nitrite species and few sulfate species produced on the surface. The reaction between HCl and the sorbent surface, and the generation of active Cl* was less sensitive to SO2. The co-presence of HCl and O2 was conducive to recovering the spent sorbent to its raw ability, and made the 0.05CuFA sustain 6 regeneration cycles. From the above advantageous aspects, this work provides an approach for cost-effectively utilizing mineral for Hg0 decontamination in coal combustion flue gas, and a universal mindset for exploring the Hg0 removal mechanism.

Review on the Compositional Variation of Eudialyte-Group Minerals in the Ilímaussaq Complex (South Greenland)

We review the compositional variation of eudialyte-group minerals (EGM) from the Ilímaussaq complex in South Greenland. Investigated samples cover all major rock units and associated pegmatites and aplites. The whole data set (>3000 analyses from >250 samples) exhibits variable XMn (0.1–0.5), REE (0.2–1.7 apfu), Nb (0.1–0.4), and Cl contents (0.4–1.6 apfu). Most EGM compositions are Na-rich (13–15 apfu), while deviations to Na-rich but also to Na-poor compositions occur because of a combination of primary features (peralkalinity, water activity) and secondary alteration. During magma evolution, REE contents in EGM cores generally increase and reach their highest contents in the most evolved rock units of the complex. This points to the moderate compatibility of REE in EGM and a bulk D (cEGM/cmelt) value of <1 during magma differentiation. Chlorine contents in EGM cores continuously decrease, and are lowest at the rims of individual crystals, suggesting a continuous decrease of Cl activity in the magmas by large-scale EGM and sodalite extraction during the orthomagmatic stage and water enrichment during the late-magmatic stage. The overall variations of XMn across stratigraphy are only minor and likely influenced by the co-crystallization of sodic pyroxene and amphibole (c.f. aegirine, arfvedsonite) and local phase proportions. Similarly, Nb and Ti contents are influenced by co-crystallizing aenigmatite, rinkite, and others. Their presence buffers Ti and Nb contents to rather constant and low values, while their absence may cause variable enrichment on a local scale. Very low Sr contents (<0.1 apfu) in magmatic EGM from Ilímaussaq are related to the basaltic nature of the parental magmas of the complex, as large-scale plagioclase fractionation occurred prior to the formation of the Ilímaussaq magmas, effectively removing Sr from the system. This is in line with very strong negative Eu anomalies in EGM from Ilímaussaq. Consistently, Sr contents in EGM from alkaline complexes, for which foiditic parental magmas are assumed, are much higher and, in such cases, negative Eu anomalies are generally absent.

NKCC-1 mediated Cl\u2212 uptake in immature CA3 pyramidal neurons is sufficient to compensate phasic GABAergic inputs

Activation of GABAA receptors causes in immature neurons a functionally relevant decrease in the intracellular Cl− concentration ([Cl−]i), a process termed ionic plasticity. Amount and duration of ionic plasticity depends on kinetic properties of [Cl−]i homeostasis. In order to characterize the capacity of Cl− accumulation and to quantify the effect of persistent GABAergic activity on [Cl−]i, we performed gramicidin-perforated patch-clamp recordings from CA3 pyramidal neurons of immature (postnatal day 4–7) rat hippocampal slices. These experiments revealed that inhibition of NKCC1 decreased [Cl−]i toward passive distribution with a time constant of 381 s. In contrast, active Cl− accumulation occurred with a time constant of 155 s, corresponding to a rate of 15.4 µM/s. Inhibition of phasic GABAergic activity had no significant effect on steady state [Cl−]i. Inhibition of tonic GABAergic currents induced a significant [Cl−]i increase by 1.6 mM, while activation of tonic extrasynaptic GABAA receptors with THIP significantly reduced [Cl−]i.. Simulations of neuronal [Cl−]i homeostasis supported the observation, that basal levels of synaptic GABAergic activation do not affect [Cl−]i. In summary, these results indicate that active Cl−-uptake in immature hippocampal neurons is sufficient to maintain stable [Cl−]i at basal levels of phasic and to some extent also to compensate tonic GABAergic activity.

A clean process for chloridion removal from manganese sulfate electrolyte using bismuthyl sulfate

In this study, a novel, efficient, and eco-friendly method is proposed to precipitate Cl− as BiOCl from MnSO4 electrolyte using (BiO)2SO4 as the chloride removal agent. The effects of different factors on the transformation and activation of Cl− removal agent, chloride precipitation, recovery and recycling, and purification processes were investigated. Increasing the L/S ratio could promote transformation and activation, while low temperature and low pH could have positive effects on Cl− precipitation. Under optimal conditions, the chloride removal efficiency reached 95.25% and the concentration of Cl− remaining in the electrolyte was reduced to 43.96 mg/L. Following the recovery and recycling process, the recycled agent (BiO)2SO4 worked well for Cl− precipitation; subsequently, chloride open this circuit as HCl. In purification process, manganese powder was used to reduce the concentration of Bi3+ that remained in the electrolyte to avoid the introduction of new elements. Thus, the concentration of Bi3+ was reduced from 125.00 mg/L to 1.80 mg/L, and the reduced bismuth could be returned to the transformation and activation of Cl− removal agent process. This entire process involving the main elements in the reactions followed a repeatable procedure, as shown in the schematic, wherein 99.98% of bismuth could be recycled and 95.25% of chloride opened the circuit in the form of HCl.

Magma Mingling in Kimberlites: Evidence from the Groundmass Cocrystallization of Two Spinel-Group Minerals

We present the results of a detailed petrographic study of fresh coherent samples of the Menominee kimberlite sampled at site 73, located in Menominee County, MI, USA. Our objective is to account for its unusual and complex paragenetic sequence. Several generations of olivine, ilmenite, and spinel-group minerals are described. Early olivine and ilmenite are xenocrystic and were replaced or overgrown by primary minerals. Zoned microcrysts of olivine have a xenocrystic core mantled by a first rim in which rutile, geikielite, and spinel s.s. (spinel sensu stricto) cocrystallized. The in situ U–Pb dating of a microcryst of primary rutile yielded 168.9 ± 4.4 Ma, which was interpreted as the age of emplacement. The groundmass consists of olivine, spinel s.s., a magnesian ulvöspinel–ulvöspinel–magnetite (MUM) spinel, calcite, and dolomite. An extremely low activity of Si is suggested by the crystallization of spinel s.s. instead of phlogopite in the groundmass. The presence of djerfisherite microcrysts indicates high activities of Cl and S during the late stages of melt crystallization. The occurrence of two distinct spinel-group minerals (spinel s.s. and qandilite-rich MUM) in the groundmass is interpreted as clear evidence of the mingling of a magnesiocarbonatitic melt with a dominant kimberlitic melt.

Titanium complexes bearing 2,6-Bis(o-hydroxyalkyl)pyridine ligands in the ring-opening polymerization of L-Lactide and ε-caprolactone

A series of titanium (Ti) compounds bearing 2,6-bis(o-hydroxyalkyl)pyridine ligands were synthesized and investigated as catalysts for the ring-opening polymerization of ε-caprolactone (CL) and L-lactide (LA). The Ti complexes with electron-withdrawing groups in pyridine rings or steric bulky groups in hydroxymethyl groups reduced the catalytic activity in CL and LA polymerizations, and MeLPh-TiOPr2 exhibited the highest catalytic activity ([CL] = 0.5 M, [CL]:[Cat] = 100:8, 60 °C, 7.5 h, conversion = 93%; [LA] = 0.5 M, [LA]:[Cat] = 100:8, 60 °C, 3.5 h, conversion = 98%). The density functional theory calculation results revealed that CL interacted with the ligand through weak hydrogen bonds, and then approached the Ti center. After being attacked by isopropyl oxide, the carbonyl group of CL bonded to the Ti center. After the rearrangement and ring opening of CL ring, CL was converted to poly-ε-caprolactone.

The role of bioleaching microorganisms in saline water leaching of chalcopyrite concentrate

In order to tackle the dual challenge of utilizing highly refractory chalcopyrite (CuFeS2) while saving scarce freshwater resources, this study aimed to systematically understand the individual role of chemical lixiviant and bioleaching microorganisms in the complex Fe3+-Cu2+-SO42−-Cl− chalcopyrite leaching system. In general freshwater bioleaching conditions, the Eh level sharply increased, and the “high-Eh-bioleaching” became the major leaching driving force. In this case, the lowest Cu yield was obtained. The chalcopyrite leaching reaction responded differently to different salinity levels. At a low salinity of 0.5% NaCl, chemical Cl−-leaching effect resulted in a higher Cu yield than the fresh-water “high-Eh-bioleaching” system. The growth of tested microbes was observed at 0.5% NaCl, but partial deactivation of microbial Fe-oxidation suppressed the Eh level. Under this condition, synergism between the chemical Cl−-leaching effect and the “low-Eh-bioleaching” effect was found. At a high salinity of 2% NaCl, on the other hand, no active cell growth was observed, and thus pre-grown cells were used to mimic the presence of Cl−-tolerant cells. Chemical Cl−-leaching readily proceeded at 2% NaCl at low Eh, but quickly ceased upon the depletion of H+. The presence of bioleaching cells somewhat slowed down the speed of chemical Cl−-leaching, but the acid depletion was alleviated by microbial acid generation. Chemical Cl−-leaching, which favors low Eh condition, was the main driving force for chalcopyrite leaching at 2% NaCl. Therefore, the activity of Cl−-tolerant S-oxidizer alone, rather than mixed Fe- and S-oxidizing consortium, was shown to play a critical role in maximizing the chalcopyrite dissolution.

Intracellular Cl- Regulation of Ciliary Beating in Ciliated Human Nasal Epithelial Cells: Frequency and Distance of Ciliary Beating Observed by High-Speed Video Microscopy.

Small inhaled particles, which are entrapped by the mucous layer that is maintained by mucous secretion via mucin exocytosis and fluid secretion, are removed from the nasal cavity by beating cilia. The functional activities of beating cilia are assessed by their frequency and the amplitude. Nasal ciliary beating is controlled by intracellular ions (Ca2+, H+ and Cl−), and is enhanced by a decreased concentration of intracellular Cl− ([Cl−]i) in ciliated human nasal epithelial cells (cHNECs) in primary culture, which increases the ciliary beat amplitude. A novel method to measure both ciliary beat frequency (CBF) and ciliary beat distance (CBD, an index of ciliary beat amplitude) in cHNECs has been developed using high-speed video microscopy, which revealed that a decrease in [Cl−]i increased CBD, but not CBF, and an increase in [Cl−]i decreased both CBD and CBF. Thus, [Cl−]i inhibits ciliary beating in cHNECs, suggesting that axonemal structures controlling CBD and CBF may have Cl− sensors and be regulated by [Cl−]i. These observations indicate that the activation of Cl− secretion stimulates ciliary beating (increased CBD) mediated via a decrease in [Cl−]i in cHNECs. Thus, [Cl−]i is critical for controlling ciliary beating in cHNECs. This review introduces the concept of Cl− regulation of ciliary beating in cHNECs.

Expression patterns of chloride transporters in the auditory brainstem of developing chicken

GABAergic transmission changes from depolarization to hyperpolarization in most vertebrate brain regions during development. By contrast, in the auditory brainstem of chicken a depolarizing effect of GABA persists after hatching. Since auditory brainstem neurons that receive GABAergic input have a Cl− reversal potential above resting membrane potential, a specifically tuned activity of Cl− transporters is likely. We here present a developmental study of the expression patterns of several members of the SLC12 family (NKCC1, NKCC2, KCC1, KCC2, KCC4, CCC6, CCC9) and of AE3 at developmental ages E7, E10, E12, E15, E17, and P1 with quantitative RT-PCR. NKCC2 and CCC9 were not detected in auditory brainstem (positive control: kidney). KCC1, CCC6 and AE3 were expressed, but not regulated, while NKCC1, KCC2 and KCC4 were regulated. The expression of the latter transporters increased, with KCC2 exhibiting the strongest expression at all time points. Biochemical analysis of the protein expression of NKCC1, KCC2 and KCC4 corroborated the findings on the mRNA level. All three transporters showed a localization at the outer rim of the cells, with NKCC1 and KCC2 expressed in neurons, and KCC4 predominantly in glia. The comparison of the published chloride reversal potential and expression of transporter proteins suggest strong differences in the efficiency of the three transporters. Further, the strong KCC2 expression could reflect a role in the structural development of auditory brainstem synapses that might lead to changes in the physiological properties.

Cystic Echinococcosis of the Breast - Diagnostic Dilemma or just a Rare Primary Localization.

Although the liver and lung are the most frequently affected organs in cystic echinococcosis, the cysts may develop in any viscera and tissues. Breast is a rare primary localization with few cases described in the literature. We present an updated and systematic review and discuss the possible mechanisms of spreading, diagnostic and treatment options. We performed a literature search in PUBMED using the key words ‘hydatid disease’, ‘cystic echinococcosis’ and ‘breast echinococcosis’ without time limitation. Only studies reporting breast cystic echinococcosis were included. Overall, 121 cases with cystic echinococcosis and 2 with alveolar echinococcosis were reported. A total of 52 cases were included in the analysis. The mean size of cysts was 5.5 cm (range 1.7-12). The most common clinical presentation was painless lump presented from 4 months to 19 years before the final diagnosis. Most cases had isolated breast CE, few cases had synchronous localizations – femoral, thigh and lung, and previous liver CE. Most were active CL and CE1-2 cysts (72%). Ultrasound was used in 83%, followed by mammography (35%). Fine needle aspiration was reported in 27 cases with positive finding in 59%. In cases with cystic breast lesions from endemic regions we recommend the US as a gold standard. CT and MRT are more accurate but expensive tools without the potential to change the surgical tactic. In contrast to the other localizations of CE, complete excision of the cysts is the best diagnostic and treatment approach.

Promotional removal of gas-phase Hg0 over activated coke modified by CuCl2.

Impregnating CuCl2 on AC (activated coke) support to synthesize xCuCl2/AC showed superior activity with higher 90% Hg0 removal efficiency at 80-140 °C, as well as a lower oxygen demand of 2% O2 for Hg0 removal. The acceleration on Hg0 removal was observed for NO and SO2. The BET, SEM, XRD, XPS, TPD, and FT-IR characterizations revealed that the larger surface area, sufficient active oxygen species and co-existence of Cu+ and Cu2+ may account for the efficient Hg0 removal. In addition, the low demand of gaseous O2 was contributed to higher content of active oxygen and formed active Cl. After adsorbing on Cu sites, Cl sites, and surface functional groups, the Hg0(ads) removal on xCuCl2/AC was proceeded through two ways. Part of Hg0(ads) was oxidized by active O and formed Hg0, and the other part of Hg0 combined with the active Cl, which was formed by the activation of lattice Cl with the aid of active O, and formed HgCl2. Besides, the Hg2+ detected in outlet gas through mercury speciation conversion and desorption peak of HgCl2 and Hg0 further proved it. As displayed in stability test and simulated industrial application test, CuCl2/AC has a promising industrial application prospect.

SGK1 mediates the hypotonic protective effect against H2O2-induced apoptosis of rat basilar artery smooth muscle cells by inhibiting the FOXO3a/Bim signaling pathway.

Serum- and glucocorticoid-inducible kinease-1 (SGK1) is a serine/threonine kinase regulated by hypotonic stimuli, which is involved in regulation of cell cycle and apoptosis. Our previous study shows that activation of volume-regulated Cl− channels (VRCCs) protects rat basilar artery smooth muscle cells (BASMCs) against hydrogen peroxide (H2O2)-induced apoptosis. In the present study, we investigated whether SGK1 was involved in the protective effect of VRCCs in BASMCs. We showed that hypotonic challenge significantly reduced H2O2-induced apoptosis, and increased SGK1 phosphorylation, but did not affect SGK1 protein expression. The protective effect of hypotonic challenge against H2O2-induced apoptosis was mediated through inhibiting mitochondria-dependent apoptotic pathway, evidenced by increased Bcl-2/Bax ratio, stabilizing mitochondrial membrane potential (MMP), decreased cytochrome c release from the mitochondria to the cytoplasm, and inhibition of the activation of caspase-9 and caspase-3. These protective effects of hypotonic challenge against H2O2-induced apoptosis was diminished and enhanced, respectively, by SGK1 knockdown and overexpression. We further revealed that SGK1 activation significantly increased forkhead box O3a (FOXO3a) phosphorylation, and then inhibited the translocation of FOXO3a into nucleus and the subsequent expression of Bcl-2 interacting mediator of cell death (Bim). In conclusion, SGK1 mediates the protective effect of VRCCs against H2O2-induced apoptosis in BASMCs via inhibiting FOXO3a/Bim signaling pathway. Our results provide compelling evidences that SGK1 is a critical link between VRCCs and apoptosis, and shed a new light on the treatment of vascular apoptosis-associated diseases, such as vascular remodeling, angiogenesis, and atherosclerosis.

SNX27 regulates DRA activity and mediates its direct recycling by PDZ-interaction in early endosomes at the apical pole of Caco2 cells.

DRA (downregulated in adenoma, SLC26A3) and NHE3 (Na+/H+ exchanger 3, SLC9A3) together mediate intestinal electroneutral NaCl absorption. Both transporters contain PDZ (postsynaptic density 95, disc large, zonula occludens 1) binding motifs and interact with PDZ adaptor proteins regulating their activity and recycling. SNX27 (sorting nexin 27) contains a PDZ domain and is involved in the recycling of cargo proteins including NHE3. The interaction of SNX27 with DRA and its potential role for the activity and recycling of DRA have been evaluated in this study. SNX27 specifically interacts with DRA via its PDZ domain. The knockdown (KD) of SNX27 reduced DRA activity by 50% but was not accompanied by a decrease of DRA surface expression. This indicates that DRA is trafficked to specific functional domains in the plasma membrane in which DRA is particularly active. Consistently, the disruption of lipid raft integrity by methyl-β-cyclodextrin has an inhibitory effect on DRA activity that was strongly reduced after SNX27 KD. In differentiated intestinal Caco2 cells, superresolution microscopy and a novel quantitative axial approach revealed that DRA and SNX27 colocalize in rab5-positive early endosomes at the apical pole. SNX27 regulates the activity of DRA in the apical plasma membrane through binding with its PDZ domain. This interaction occurs in rab5-positive early endosomes at the apical pole of differentiated intestinal Caco2 cells. SNX27 is involved in the direct recycling of DRA to the plasma membrane where it is inserted into lipid rafts facilitating increased activity.NEW & NOTEWORTHY SNX27 has a PDZ domain and is involved in the regulation and recycling of transmembrane proteins. The role of SNX27 on the activity and recycling of the intestinal Cl-/ exchanger DRA has not yet been studied. This study shows that SNX27 directly interacts with DRA in early endosomes at the apical pole of intestinal Caco2 cells and mediates its direct recycling to facilitate high activity in lipid rafts in the apical plasma membrane.

Elucidating the mechanism of Hg0 oxidation by chlorine species over Co3O4 catalyst at molecular level

Co3O4 has been considered as promising active catalyst component for mercury control because of its excellent catalytic and long persistent activity. The heterogeneous mechanisms of Hg0 oxidation by HCl and Cl2 upon Co3O4(1 1 0) surface were studied using density functional theory (DFT) calculations. The results demonstrate that both Hg0 and HgCl2 are chemisorbed upon Co3O4(1 1 0) with the binding energies of −0.74 and −1.43 eV, respectively. HgCl can be molecularly chemisorbed upon Co3O4(1 1 0) and act as intermediate during Hg0 oxidation. HCl and Cl2 dissociate on Co3O4(1 1 0) and convert into active chlorine species. Hg0 catalytic oxidation by HCl and Cl2 on Co3O4(1 1 0) proceeds with Langmuir-Hinshelwood mechanism, in which the chemisorbed Hg0 interacts with the surface active Cl atoms to produce HgCl2. The optimal oxidation pathway includes four steps: (1) Hg0 adsorption, (2) HgCl formation, (3) HgCl2 formation and (4) HgCl2 desorption. The rate-limiting step is HgCl formation with an energy barrier of 0.67 eV. Hg0 oxidation by HCl is thermodynamically and kinetically more favorable than that by Cl2 because the presence of H atoms weakens the interaction between reaction intermediate and Co3O4 surface.

TGF-β1 Augments the Apical Membrane Abundance of Lemur Tyrosine Kinase 2 to Inhibit CFTR-Mediated Chloride Transport in Human Bronchial Epithelia.

The most common disease-causing mutation in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene, F508del, leads to cystic fibrosis (CF), by arresting CFTR processing and trafficking to the plasma membrane. The FDA-approved modulators partially restore CFTR function and slow down the progression of CF lung disease by increasing processing and delivery to the plasma membrane and improving activity of F508del-CFTR Cl– channels. However, the modulators do not correct compromised membrane stability of rescued F508del-CFTR. Transforming growth factor (TGF)-β1 is a well-established gene modifier of CF associated with worse lung disease in F508del-homozygous patients, by inhibiting CFTR biogenesis and blocking the functional rescue of F508del-CFTR. Lemur tyrosine kinase 2 (LMTK2) is a transmembrane protein localized at the apical and basolateral membrane domain of human bronchial epithelial cells. Phosphorylation of the apical membrane CFTR by LMTK2 triggers its endocytosis and reduces the abundance of membrane-associated CFTR, impairing the CFTR-mediated Cl– transport. We have previously shown that LMTK2 knockdown improves the pharmacologically rescued F508del-CFTR abundance and function. Thus, reducing the LMTK2 recruitment to the plasma membrane may provide a useful strategy to potentiate the pharmacological rescue of F508del-CFTR. Here, we elucidate the mechanism of LMTK2 recruitment to the apical plasma membrane in polarized CFBE41o- cells. TGF-β1 increased LMTK2 abundance selectively at the apical membrane by accelerating its recycling in Rab11-positive vesicles without affecting LMTK2 mRNA levels, protein biosynthesis, or endocytosis. Our data suggest that controlling TGF-β1 signaling may attenuate recruitment of LMTK2 to the apical membrane thereby improving stability of pharmacologically rescued F508del-CFTR.

Neuropeptide regulation of secretion and inflammation in human airway gland serous cells.

Airway submucosal gland serous cells are sites of expression of the cystic fibrosis transmembrane conductance regulator (CFTR) and are important for fluid secretion in conducting airways. To elucidate how neuropeptides regulate serous cells, we tested if human nasal turbinate serous cells secrete bicarbonate (HCO3 -), important for mucus polymerisation and antimicrobial peptide function, during stimulation with cAMP-elevating vasoactive intestinal peptide (VIP) and if this requires CFTR. Serous cells stimulated with VIP exhibited a ∼15-20% cAMP-dependent decrease in cell volume and a ∼0.15 unit decrease in intracellular pH (pHi), reflecting activation of Cl- and HCO3 - secretion, respectively. HCO3 - secretion was directly dependent on CFTR and was absent in cells from CF patients. In contrast, neuropeptide Y (NPY) reduced VIP-evoked cAMP increases, CFTR activation, and Cl-/HCO3 - secretion. Culture of primary serous cells in a model that maintained a serous phenotype confirmed the activating and inhibiting effects of VIP and NPY, respectively, on fluid and HCO3 - secretion. Moreover, VIP enhanced antimicrobial peptide secretion and antimicrobial efficacy of secretions while NPY reduced antimicrobial efficacy. In contrast, NPY enhanced cytokine release while VIP reduced cytokine release through a mechanism requiring CFTR. As levels of VIP and NPY are up-regulated in diseases like allergy, asthma, and chronic rhinosinusitis, the balance of these two peptides in the airway may control mucus rheology and inflammatory responses in serous cells. Furthermore, the loss of CFTR conductance in serous cells may contribute to CF pathophysiology by increasing serous cells inflammatory responses in addition to directly impairing Cl- and HCO3 - secretion.

Refined understanding of groundwater in heterogeneous units through identification of vertical stratification of hydrochemistry as identified in the Walloon subgroup of Australia’s Great Artesian Basin

Groundwater management in the Great Artesian Basin (Australia) is challenging due to the large areas and heterogeneity of sequences involved. This challenge has often been addressed with up-scaled conceptual models; however, where there is significant heterogeneity or local competing groundwater uses, more detail is required. When good understanding of heterogeneity within sequences is not available, the upscaled approach can lead to a disparity between model predictions based on homogenisation inherent in upscaling and the observed behaviour of heterogeneous systems, leading to bias in results. This requires improved conceptual resolution of these heterogeneous systems. Geological data are often insufficient to achieve the required resolution. This paper reports on the use of hydrochemical data from existing bores in the Walloon subgroup of the Surat Basin, using compositional data analysis techniques to refine the unit description. The approach moves beyond simple hydrochemical characterisations of water type via conventional hydrochemical interpretations to use a combination of centred- and isometric-log ratios to describe discrete end members. The results show that, despite similar water types, the upper Juandah and lower Taroom coal seams of Walloon subgroup are distinguished by an inverse relationship between ions Cl−, Ca2+, Mg2+, Sr2+, Li− and H+ and ions HCO3−, F− and B3+, and by an isometric log ratio that describes the balance between the activities of Cl, H+ and HCO3. These relationships suggest that higher-resolution conceptual models based on flow paths mapped from hydrochemical data can form the basis for refined groundwater models that address both heterogeneity and regional model domains.

Experimental study on the microreactor-assisted synthesis of phosphinic chlorides with varying steric hindrance

An efficient and catalyst-free method for the preparation of optically active and racemic mono-substituted t-butyl phosphinic chlorides tBuRP(O)Cl under flow conditions was reported.

Luminescence of uranium(VI) after liquid-liquid extraction from HCl by Aliquat® 336 in n-dodecane:1-decanol by time-resolved laser-induced luminescence spectroscopy

Abstract To investigate the extraction of uranium(VI) in HCl media by Aliquat® 336 in 1:99 (v:v) 1-decanol:n-dodecane mixture, our objective is to identify the complexe(s) in the organic phase by time-resolved laser-induced luminescence spectroscopy (TRLS). The extraction mechanism is supposed to involve the formation of [ U O 2 C l 4 2 − ⋅ ( R 4 N + ) 2 ] $[U{O_2}Cl_4^{2 - } \cdot {({R_4}{N^ + })_2}]$ in the organic phase. The occurrence of such a species leads to the presence of the UO 2 Cl 4 2 − ${\rm{U}}{{\rm{O}}_2}{\rm{Cl}}_4^{2 - }$ species in the organic solution, which luminescence shows particular features. The luminescence spectra and decay time evolutions are obtained in the organic phase as a function of HCl concentration in the aqueous phase (0.5–6 M). The extraction of UO 2 Cl 4 2 − ${\rm{U}}{{\rm{O}}_2}{\rm{Cl}}_4^{2 - }$ is confirmed by the particular spectrum of uranium(VI) in the organic phase, and the typical splitting of the luminescence bands, due to the crystal field effect, is clearly evidenced. The stoichiometry is verified using luminescence intensity variation as a function of the activity of Cl−, and extraction constants are calculated both using the specific interaction theory and Pitzer model. A decomposition of the spectrum of the extracted complex in the organic phase is also proposed. The decay time variation as a function of temperature allows estimating the activation energy of the luminescence process of the extracted complex.