Low Cl Research Articles

Evaluating Polymeric Sampling as a Tool for Predicting the Bioaccumulation of Polychlorinated Biphenyls by Fish and Shellfish.

Recent research has shown that polymeric sampling data generally can predict the bioaccumulation of hydrophobic organic contaminants by benthic and sessile invertebrates. Based on literature data, this review evaluated polymeric sampling as a tool for predicting the bioaccumulation of polychlorinated biphenyls (PCBs) by pelagic and mobile fish and shellfish. Lipid-normalized concentrations (CL) were linked to corresponding equilibrium polymer concentrations (CP) to evaluate the (1) correlation between CL and CP, (2) accuracy when using CP as surrogates for CL, (3) effects of experimental variables on these results, and (4) implications associated with this approach. Generally, strong positive log-log linear correlations existed between CL and CP, meaning that increasing bioaccumulation was well-reflected by increasing polymer accumulation. Further, the majority of the regression lines, as well as individual CL to CP ratios, were within a factor of 10 from the hypothetical 1:1 relationship, suggesting that polymers accumulated concentrations comparable to body residues in fish and shellfish. Interestingly, overall stronger correlations and lower CL to CP ratios resulted when CP were based on sediment compared to water column-deployed samplers. These findings provide a tool for environmental managers when assessing and managing risk associated with PCB-contaminated sediments and waters in protecting vulnerable fish and shellfish species.

Leaf mesophyll K+ and Cl− fluxes and reactive oxygen species production predict rice salt tolerance at reproductive stage in greenhouse and field conditions

Extensive research on salinity tolerance in rice has been mostly carried out at the seedling stage in single experimental trials. Here, we aimed to understand the roles of ion transport and oxidative responses of leaf mesophyll in salinity tolerance of rice (Oryza sativa L.) at its reproductive stage using comparative investigations in both greenhouse and field trials. Two experimental trials were conducted to assess the salt tolerance of three rice cultivars at their reproductive stage in greenhouse and field. We employed agronomic, physiological, electrophysiological, molecular and cell imaging techniques to compare physiological response of control and salinity stressed rice plants. Salinity had the most severe effect to Koshihikari, followed by Doongara and Reiziq. We found that K+ retention and low recovery Cl− efflux in mesophyll cells confers salt tolerance in rice. Moderate to strong correlations were found between growth parameters and net K+ flux (r2 = 0.45–0.60), and net Cl− flux (r2 = 0.47–0.72). Also, dynamic ROS production and regulation of the NADPH oxidase gene, OsRBOHD, in mesophyll cells is crucial for salt tolerance of rice at the reproductive stage. OsRBOHD expression was significantly correlated to recovery ion fluxes (r2 = 0.45–0.64). This study brings together, for the first time, potential links between cellular ionic stress and oxidative stress components of salinity tolerance in rice at the reproductive stage in both greenhouse and field conditions. Our study will provide guidance to examine crop salinity tolerance at reproductive stages in controlled environments and natural climatic conditions in the future.

Low-chloride- versus high-chloride-containing hypertonic solution for the treatment of subarachnoid hemorrhage\u2013related complications: The ACETatE (A low ChloriE hyperTonic solution for brain Edema) randomized trial

BackgroundRecent reports have demonstrated that among patients with subarachnoid hemorrhage (SAH) treated with hypertonic NaCl, resultant hyperchloremia has been associated with the development of acute kidney injury (AKI). We report a trial comparing the effect of two hypertonic solutions with different chloride contents on the resultant serum chloride concentrations in SAH patients, with a primary outcome aimed at limiting chloride elevation.MethodsA low ChloridE hyperTonic solution for brain Edema (ACETatE) trial is a single-center, double-blinded, double-dummy, randomized pilot trial comparing bolus infusions of 23.4% NaCl and 16.4% NaCl/Na-acetate for the treatment of cerebral edema in patients with SAH. Randomization occurred when patients developed hyperchloremia (serum Cl− ≥ 109 mmol/L) and required hyperosmolar treatment.ResultsWe enrolled 59 patients, of which 32 developed hyperchloremia and required hyperosmolar treatment. 15 patients were randomized to the 23.4% NaCl group, and 17 patients were randomized to the 16.4% NaCl/Na-acetate group. Although serum chloride levels increased similarly in both groups, the NaCl/Acetate group showed a significantly lower Cl− load at the end of the study period (978mEq vs. 2,464mEq, p < 0.01). Secondary outcome analysis revealed a reduced rate of AKI in the Na-acetate group (53.3% in the NaCl group vs. 11.8% in the Na-acetate group, p = 0.01). Both solutions had similar effects on ICP reduction, but NaCl/Acetate treatment had a more prominent effect on immediate post-infusion Na+ concentrations (increase of 2.2 ± 2.8 vs. 1.4 ± 2.6, (p < 0.01)). Proximal tubule renal biomarkers differed in concentration between the two groups.ConclusionsOur pilot trial showed the feasibility and safety of replacing 23.4% NaCl infusions with 16.4% NaCl/Na-acetate infusions to treat cerebral edema in patients with SAH. The degree of hyperchloremia was similar in the two groups. 16.4% NaCl/Na-acetate infusions led to lower Cl− load and AKI rates than 23.4% NaCl infusions. Further multi-center studies are needed to corroborate these results.Trial registrationclinicaltrials.gov # NCT03204955, registered on 6/28/2017

Spectroscopic Characterization of Halorhodopsin Reconstituted into Nanodisks Using Native Lipids

We successfully reconstituted single Natronomonas pharaonis halorhodopsin (NpHR) trimers into a nanodisk (ND) using the native archaeal lipid (NL) and an artificial lipid having a zwitterionic headgroup, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). Incorporation of single trimeric NpHR into NDs was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis, size-exclusion chromatography, and visible circular dichroism spectroscopy. The Cl− binding affinity of NpHR in NDs using NL (NL-ND NpHR) or POPC (POPC-ND NpHR) was examined by absorption spectroscopy, showing that the Cl−-releasing affinities (Kd,N↔O) of these ND-reconstituted NpHRs are more than 10 times higher than that obtained from native NpHR membrane fragments (MFs) harvested from a NpHR-overexpressing archaeal strain (MF NpHR). The photoreaction kinetics of these ND-reconstituted NpHRs revealed that the Cl− uptake was faster than that of MF NpHR. These differences in the Cl−-releasing and uptake properties of ND-reconstituted NpHRs and MF NpHR may arise from suppression of protein conformational changes associated with Cl− release from the trimeric NpHR caused by ND reconstitution, conformational perturbation in the trimeric state, and loss of the trimer-trimer interactions. On the other hand, POPC-ND NpHR demonstrated accelerated Cl− uptake compared to NL-ND NpHR, suggesting that the negative charge on the archaeal membrane surface regulates the photocycle of NpHR. Although NL-ND NpHR and MF NpHR are embedded in the same lipid, the lower Cl−-binding affinity at the initial state (Kd,initial) and faster recovering from the NpHR′ state to the original state of the photoreaction cycle were observed for NL-ND NpHR, probably because of insufficient interactions with a chromophore in the native membrane, bacterioruberin in reconstituted NDs. Our results indicate that specific interactions of NpHR with surrounding lipids and bacterioruberin, structural flexibility of the membrane, and interactions between trimeric NpHRs may be necessary for efficient Cl− pumping.

Biotite geochemistry deciphers magma evolution of Sn-bearing granite, southern Myanmar

Hydrothermal Sn ± W deposits are commonly formed by ore-forming fluids that exsolved from water-saturated granitic magmas. However, the timing of fluid exsolution and its influence on volatiles and ore-forming elements still remain confused. For this purpose, geochemical and OH isotopic compositions of biotite from Late Cretaceous-Eocene granitic intrusions in the Sibumasu terrane (southern Myanmar) are presented. MnO content of biotite is a well negative correlation with the amount of biotite and whole-rock (La/Yb)N ratio, indicating that it could be a good index of granitic magma differentiation. Cl content of biotite from Paleocene granite shows an increased first and subsequently decreased trend with increasing MnO content (0.71–2.36 wt%), suggesting Cl enrichment by magma evolution and depletion by late-stage fluid exsolution. Fluid exsolution is also supported reduced Li contents of biotite and OH isotopic compositions of residual magmatic water equilibrated with high-MnO biotite (δ18O = 7.0 to 8.8‰ and δD = −114 to −93.5‰). All studied biotite grains from Late Cretaceous granite have low Cl contents (0.01–0.11 wt%), decreased Li with increasing MnO contents, and residual magmatic water-like OH isotopic values (δ18O = 6.9‰ and δD = −105‰), indicating that their host granitic melts had undergone fluid exsolution. Importantly, a positive correlation between Sn and MnO contents in biotite suggests that magma differentiation is a dominant process for Sn enrichment. No depletion of Sn by fluid exsolution likely caused by low salinity fluids exsolved from Cl-poor granitic melts, which were estimated by low Cl contents of biotite (<0.2 wt%). The reduced Nb and Ta contents in high-MnO biotite possibly resulted by fractionation of Nb/Ta-bearing minerals during late-stage magma evolution. Moreover, ore-forming fluids equilibrated with hydrothermal muscovite from Sn-bearing quartz veins have consistent OH isotopic compositions (δ18O = 6.8–7.0‰ and δD = −61.9 to −90.2‰) with magmatic water, suggesting that ore-forming fluids probably exsolved from more evolved granitic melts with strong Sn and F enrichment.

Chloride involvement in the synthesis, functioning and repair of the photosynthetic apparatus in vivo.

Cl- has long been known as a micronutrient for oxygenic photosynthetic resulting from its role an essential cofactor for photosystem II (PSII). Evidence on the in vivo Cl- distribution in Spinacia oleracea leaves and chloroplasts shows that sufficient Cl- is present for the involvement in PSII function, as indicated by in vitro studies on, among other organisms, S.oleracea PsII. There is also sufficient Cl- to function, with K+ , in parsing the H+ electrochemical potential difference (proton motive force) across the illuminated thylakoid membrane into electrical potential difference and pH difference components. However, recent in vitro work on PSII from S.oleracea shows that oxygen evolving complex (OEC) synthesis, and resynthesis after photodamage, requires significantly higher Cl- concentrations than would satisfy the function of assembled PSII O2 evolution of the synthesised PSII with the OEC. The low Cl- affinity of OEC (re-)assembly could be a component limiting the rate of OEC (re-)assembly.

Magmatic evolution and post-crystallization hydrothermal activity in the early Cretaceous Pingtan intrusive complex, SE China: records from apatite geochemistry

We conducted in situ geochemical (major-, trace-element and Nd isotope compositions) analyses on apatite, together with whole-rock geochemistry from gabbro, granodiorite and granite in the Cretaceous Pingtan intrusive complex (SE China), aiming to investigate the roles of magmatic evolution and post-crystallization hydrothermal activity during its formation. Regardless of limited range in initial Nd isotopes ranges in both bulk rock [ɛNd(t) = − 2.0 to − 0.4] and associated apatite [ɛNd(t) = − 3.8 to − 0.4] from the Pingtan igneous complex, the apatite shows wide compositional and textural variations from gabbro to granite. Apatite from the gabbro (Group 1) displays a zoning structure characterized by increasing F and Sr but decreasing Cl and LREE from the core to rim. The increase of Sr from the core to rim is attributed to plagioclase accumulation, and the decreases of LREE and Cl from the core to rim is caused by post-crystallization hydrothermal activity. The high Cl content in the primitive Group 1 apatite further suggests derivation of the mafic magma from a mantle wedge metasomatized by Cl-rich sediment. In contrast, apatite from the granite (Group 2) has the lowest Cl and Sr but the highest F and Yb contents, which can be further divided into two subgroups of Group 2A and 2B based on texture and composition. Group 2A apatite shows homogenous composition with trace elements similar to apatite from I-type granite. The positive correlation between Sr and Eu/Eu* indicates that crystallization of Group 2A apatite is co-precipitated with a feldspar-dominated fractionation. However, Group 2B apatite contains mineral inclusion of monazite and has the highest U content and F/Cl ratio, resembling apatite from S-type or highly fractionated I-type granite. These features are consistent with the influence of post-crystallization hydrothermal activity. Apatite from the granodiorite (Group 3) has an intermediate composition between Group 1 and 2A apatite and shows a homogenous texture with trace element features similar to that from I-type granite. Group 3 apatite defined a negative correlation of Sr with La/Yb, which is attributed to fractional crystallization of hornblende and plagioclase. The geochemistry of apatite indicates that the gabbro and granitic rocks of the Pingtan intrusive complex were, respectively, derived from the mantle and crustal sources with similar ɛNd(t) values. Our study, therefore, demonstrates that apatite geochemistry has a potential to monitor the magma source, magmatic evolution and post-crystallization fluid activity of an igneous complex.

Production of high quality empty fruit bunch pellet by water washing and torrefaction

EFB pellet is the high potential biomass for combustion process due to the relatively high heating value and the high availability in the Southern of Thailand. However, the containing of high unwanted minerals, especially K and Cl is the main drawback of EFB pellet which causing the ash fouling or/and slagging during the combustion. In this study, the high quality EFB pellets (low K, low Cl, high heating value) were produced by applying the water washing and torrefaction methods. For water washing treatment, the effect of water and acetic acid solution on the mineral content of EFB pellet was studied. In addition, the effect of torrefaction temperature (250, 280 and 300 °C) on the quality of EFB pellet was investigated. Results revealed that the ash content of the washed EFB decreased from 5.3 % to 3.0 % and 0.7 % by washing with tap water and acetic acid solution, respectively. Comparing with the raw EFB pellet, K and Cl in ash were significantly reduced by washing about 60 % and 88 %, respectively. Heating value of the EFB and washed EFB pellet were increased after torrefaction with the higher temperature. The water washed EFB pellet and torrefied at 300 °C gave the highest heating value about 24.3 MJ/kg. It was 33% increased HHV when comparing with raw EFB pellet.

Compositions of Dust and Sea Salts in the Dome C and Dome Fuji Ice Cores From Last Glacial Maximum to Early Holocene Based on Ice‐Sublimation and Single‐Particle Measurements

AbstractWe analyzed the chemical compositions of dust and sea‐salt particles in the EPICA Dome C (EDC) ice core during 26–7 kyr BP using an ice‐sublimation technique and compared the results with existing data of the Dome Fuji (DF) ice core. Combined with ion concentration data, our data suggested similar sea‐salt fluxes in both cores and significantly lower dust flux in the EDC core. The differences in modal size and aspect ratio of dust particles between the two cores support the dominance of Patagonian source suggested by earlier works. The compositions of calcic dust showed major change at ~17 kyr BP, possibly reflecting a relative increase in dust transported via the upper troposphere. The calcium sulfate fraction was higher in the DF core than in the EDC core after ~17 kyr BP, suggesting that higher Patagonian dust contribution to the DF region. Abundant NaCl particles were found in the DF core in comparison with the EDC core from the LGM to early Holocene, possibly because of the high concentration of terrestrial dust in the DF core that reduced acid availability for sea‐salt modification. During the Holocene, the lower NaCl fraction and Cl−/Na+ ratio in the EDC core suggested that most Cl− was lost to the atmosphere from snow at Dome C, while it was preserved at Dome Fuji as NaCl and solid solution.

Effects of the formation of reactive chlorine species on oxidation process using persulfate and nano zero-valent iron

The chloride ion (Cl−) is a matrix ion that plays crucial roles in radical-based oxidation processes used to treat brackish or saline water. Here, the effects of the formation of reactive chlorine species on the performance of and reaction mechanisms involved in persulfate/nano zero-valent iron process were evaluated by investigating the reaction kinetics and performing reactive species scavenging tests. The phenol oxidation rate increased markedly in the early reaction stage in the presence of 25–200 mM of Cl−. This was because excess sulfate radicals (SO4−) reacted with Cl− to produce short-lived reactive chlorine species such as Cl and Cl2− rather than being scavenged by Fe2+ or other SO4−. The reactive chlorine species caused OH to form through radical propagation reactions. The total numbers of reactive species involved in phenol oxidation were higher at brackish to weakly saline Cl− concentrations than at lower and higher Cl− concentrations. At high Cl− concentrations (>400 mM), the phenol oxidation rate decreased because most of the SO4− reacted with Cl− to give large amounts of weaker oxidants such as Cl2− and HOCl. Acceleration of Fe corrosion by Cl− negligibly affected the persulfate/nano zero-valent iron oxidation process.

In situ major and trace element compositions of apatite from the Yangla skarn Cu deposit, southwest China: Implications for petrogenesis and mineralization

The Yangla copper deposit is a rare Triassic intrusion-related Cu skarn system in the central part of the Jinshajiang tectonic belt, central Sanjiang orogenic belt, southwest China. Major- and trace-element compositions of apatites from ores, fertile calc-alkaline intrusions and its mafic microgranular enclaves, and barren calc-alkaline intrusions from the Yangla skarn copper deposit were measured by electron probe microanalysis and laser ablation–inductively coupled plasma–mass spectrometry. Results indicate that apatites grown within ores, fertile intrusions and its enclaves show similar features, but are different from that grown within barren intrusions. Apatite from fertile intrusions has higher Ca and correspondingly lower total trace-element contents, which partition onto the Ca sites, relative to that from barren intrusions. Apatites from the barren intrusions have high F and low Cl contents, and correspondingly high F/Cl ratios, which may have resulted from the assimilation of sediment. Apatites from fertile intrusions show relatively high Cl and low F contents, which may reflect crystallization from magmas with high water contents. Redox-sensitive elements in apatite can be used as indicators of the oxidation state of magmas. Apatites from the barren intrusion have lower V and As contents, higher Mn, Fe, and U contents, and more pronounced negative Eu anomalies than those from fertile intrusion, indicating that the barren magma was more reduced, consistent with its lower whole-rock Fe2O3/FeO and zircon Ce4+/Ce3+ ratios. These findings demonstrate that apatites are effective in distinguishing fertile from barren intrusions and can be used as a robust tool in mineral exploration.

Atomically dispersed Pt\u2013N4 sites as efficient and selective electrocatalysts for the chlorine evolution reaction

Chlorine evolution reaction (CER) is a critical anode reaction in chlor-alkali electrolysis. Although precious metal-based mixed metal oxides (MMOs) have been widely used as CER catalysts, they suffer from the concomitant generation of oxygen during the CER. Herein, we demonstrate that atomically dispersed Pt−N4 sites doped on a carbon nanotube (Pt1/CNT) can catalyse the CER with excellent activity and selectivity. The Pt1/CNT catalyst shows superior CER activity to a Pt nanoparticle-based catalyst and a commercial Ru/Ir-based MMO catalyst. Notably, Pt1/CNT exhibits near 100% CER selectivity even in acidic media, with low Cl− concentrations (0.1 M), as well as in neutral media, whereas the MMO catalyst shows substantially lower CER selectivity. In situ electrochemical X-ray absorption spectroscopy reveals the direct adsorption of Cl− on Pt−N4 sites during the CER. Density functional theory calculations suggest the PtN4C12 site as the most plausible active site structure for the CER.

Density Functional Theory Study of the Initial Stages of Cl-Induced Degradation of α-Cr2O3 Passive Film

The ion exchange and point defect models are two prominent models describing the role of anions, such as chlorides, in the degradation of passive oxide films. Here the thermodynamic feasibility of critical steps of Cl-induced degradation of a hydroxylated α-Cr2O3 (0001) surface, as proposed by these two models, are studied. Both models begin with Cl substitution of surface OH and H2O, which becomes less favorable with increasing Cl coverage. The initial stages of Cl-induced breakdown of the α-Cr2O3 depend on Cl coverage and the presence of O vacancy near the surface as follows: (1) neither Cl insertion (supporting the ion exchange model) nor Cr vacancy formation (supporting the point defect model) is feasible at low Cl coverages except in the presence of O vacancies near the surface, where Cl insertion is thermodynamically feasible even at low coverages, (2) in the absence of O vacancies, Cr vacancy formation becomes feasible from 10/12 ML onwards whereas Cl insertion by exchange with subsurface OH only becomes feasible at full coverage. This implies that at higher coverages Cl-induced degradation first initiatesthrough a vacancy formation mechanism, but both insertion and vacancy formation would be feasible at full coverage.

Emission characteristics of size distribution, chemical composition and light absorption of particles from field-scale crop residue burning in Northeast China

Crop residue burning in China increased significantly in the last decade, especially it took up a majority in Northeast China, which plays an important role of severe haze pollution. Hence, two main types of crop residues (corn and rice straw) were chosen to characterize the particle number concentration, chemical components of fine particulate matter and optical properties of carbonaceous aerosols by a suite of fast-response online portable instruments, together with offline sampling and analysis, during the field-based combustion experiments in Northeast China. For the range of 250 and 2500 nm, more particles were emitted from rice straw burning than those from corn straw burning, and the time-averaged number concentration of particles during the flaming process was approximately 2 times higher than that during the smoldering process for these two straws. Organic carbon (OC), elemental carbon (EC) and water-soluble ions were the most abundant components and accounted for 42.5 ± 7.5%, 7.7 ± 1.7% and 18.0 ± 3.4% of the PM2.5, respectively. Furthermore, rice straw burning emitted higher OC and lower Cl− and K+ than those from corn straw burning. The average absorption Ångström exponent (AAE) of carbonaceous aerosols was 2.1 ± 0.3, while the AAE of brown carbon (BrC) was 4.7 ± 0.4 during the whole burning process. On average, BrC contributed to 63% and 20% of the total light absorption at 375 nm and 625 nm, respectively. Parameterization of BrC absorption revealed that the fraction of absorption from BrC has a reasonably good correlation with EC/OC (−0.84) and AAE (0.94) at 375 nm. Generally, combustion conditions can affect the optical properties of carbonaceous aerosols, and a negative correlation (−0.77) was observed between the AAE and modified combustion efficiency; in addition, the percentage of absorption due to BrC were lower at the flaming phase.

Physiological disturbances in juvenile sockeye salmon (Oncorhynchus nerka) exposed to the water-soluble fraction of diluted bitumen

Current and proposed transcontinental pipelines for the transport of diluted bitumen (dilbit) from the Canadian oil sands traverse the coastal watersheds of British Columbia, habitat essential to Pacific salmonids. To determine the potential risks posed to these keystone species, juvenile sockeye (Oncorhynchus nerka; 1+ parr) were acutely (24–96 h) or subchronically (21–42 d) exposed to 4 concentrations of the water-soluble fraction (WSF) of unweathered Cold Lake Blend dilbit (initial total PAC concentrations: 0, 13.7, 34.7 and 124.5 μg/L) in a flow-through system. Dilbit effects on iono-osmoregulation, the physiological stress response, and the immune system were assessed by both biochemical and functional assays. Hydrocarbon bioavailability was evidenced by a significant induction of liver ethoxyresorufin-O-deethylase (EROD) activity in exposed fish. Acute and subchronic exposure significantly reduced gill Na+-K+-ATPase activity and resulted in lower plasma osmolality, Cl−, and Na+ concentrations. Acute exposure to dilbit resulted in a classic physiological stress response, however at 21 d of exposure, plasma cortisol remained elevated while other measured parameters had returned to baseline values. A compromised immune system was demonstrated by a 29.5 % higher mortality in fish challenged with Vibrio (Listonella) anguillarum following dilbit exposure compared to unexposed controls. Exposure of juvenile salmonids to the WSF of dilbit (at TPAC concentrations at the ppb level) resulted in sublethal effects that included a classic physiological stress response, and alterations in iono-osmoregulatory homeostasis and immunological performance.

Geochemical identification of the source and environment of produced water from CBM wells and its productivity significance: examples from typical CBM wells in eastern Yunnan and western Guizhou

The geochemical information of produced water from coalbed methane (CBM) wells is abundant in geological significance. Based on the conventional ions, hydrogen and oxygen isotopes (δD and δ18O) and trace element tests of 27 produced water samples from CBM wells, the geochemical identification of the source and environment of produced water from CBM wells and its productivity significance have been analysed. The following conclusions have been drawn: CBM produced water can be divided into three categories, namely, polluted water from frac fluids, polluted surface water and formation water. The formation water has low Cl- concentration, low total dissolved solids (TDS) concentration, and light δD and δ18O. The water polluted by frac fluid has high Cl- and TDS concentrationt, and heavy δD and δ18O. The polluted surface water has high SO42- and light δD and δ18O. CBM groun dwate r environments can be divided into confined and unconfined systems. The confined system is characterized by low Na+/Cl- value, high (Cl- - Na+)/Mg2+ value, a general absence of SO42-, high Sr and Ba and low F. The unconfined system is characterized by high Na+/Cl- value, low (Cl- - Na+)/Mg2+ value, low SO42-, low Sr and Ba and high F. Constructing a cross plot with the new D drift index (d') value and Cl- concentration can further identify four types of source-water environments: an unconfined formation water system, an unconfined surface water system, a confined system heavily polluted by frac fluids, and a confined system only slightly polluted by frac fluids. The unconfined system often produces more formation water and has high CBM production. The confined system often produces water more heavily polluted by frac fluids and is low in CBM production. The fitting formulas of hydrochemical productivity have been established for daily CBM and water production of CBM wells.

The Late Mesozoic granodiorite and polymetallic mineralization in southern Anhui Province, China: A perspective from apatite geochemistry

The region of southern Anhui Province (SAP) is one of Late Mesozoic magmatic belts and copper-molybdenum-gold-tungsten polymetallic ore districts in China, but the relationship of polymetallic mineralization and related granodiorite remains unclear. Previous studies indicate that apatite can be an indicator for magmatic evolution and mineral exploration. In this study, apatites from the SAP ore-bearing granodiorites were investigated using observations from the electron microscope, electron probe microanalysis (EPMA), laser-ablation inductively-coupled plasma-mass spectrometry (LA-ICP-MS). The studied apatite samples identified as fluorapatite, show high F (2.69–4.13 wt.%) and low Cl contents (mainly<0.2 wt.%). These apatites also have high La/Y (0.41–4.69) and δEu (0.13–0.70) values, and low (Sm/Nd)N values (0.34–0.81), indicating that the SAP magma was derived from mafic I-type melt. The REE patterns, negative Eu anomalies, the negative δEu and δCe correlation, and high logfO2 values (−10.5 to −13.8) of apatites studied, further indicate that the SAP granodiorites had originated from mantle-derived magmas mixing with the lower crustal components in high oxygen fugacity environment. The results indicate that the Sr/Y and δEu values of apatite can be a good indicator to distinguish adakitic rocks from non-adakitic rocks. Moreover, the δEu value and Cl content in apatite can be effectively used to discriminate the unmineralized rocks and ore deposit types.

Common carp, Cyprinus carpio, prefer branchial ionoregulation at high feeding rates and kidney ionoregulation when food supply is limited: additional effects of cortisol and exercise.

This study aims to examine ionoregulatory parameters during exercise and cortisol elevation in common carp fed different food rations. Fish subjected to two different feeding regimes (0.5 or 3.0% body mass (BM) daily) received no implant or an intraperitoneal cortisol implant (250mg/kg BM) or sham, and were monitored over a 168-h post-implant (PI) period under resting, low aerobic swimming or exhaustive swimming conditions. Plasma osmolality was maintained at relatively stable levels without much influence of feeding, swimming or cortisol, especially in low feeding groups. Nevertheless, a transient hyponatremia was observed in all low feeding fish implanted with cortisol. The hyponatremia was more pronounced in fish swum to exhaustion but even in this group, Na+ levels returned to control levels as cortisol levels recovered (168h-PI). Cortisol-implanted fish also had lower plasma Cl- levels, and this loss of plasma Cl- was more prominent in fish fed a high ration during exhaustive swimming (recovered at 168h-PI). Cortisol stimulated branchial NKA and H+ ATPase activities, especially in high ration fish. In contrast, low ration fish upregulated kidney NKA and H+ ATPase activities when experiencing elevated levels of cortisol. In conclusion, low feeding fish experience an ionoregulatory disturbance in response to cortisol implantation especially when swum to exhaustion in contrast to high feeding fish.

Low Pre-Treatment Hemoglobin and Creatinine Clearance Correlate with Worse Overall Survival, Treatment-Related Mortality, and Regimen-Related Toxicities in Patients Undergoing a Reduced-Intensity Allogeneic Stem Cell Transplantation with Fludarabine and Melphalan

The reduced-intensity conditioning (RIC) regimen consisting of fludarabine and melphalan 140 mg/m2 (Flu/Mel140) prior to allogeneic hematopoietic stem cell transplant (HSCT) has been widely adopted in clinical practice. However, pharmacokinetic (PK) studies report up to a 10-fold interpatient variability in melphalan exposure (AUC). Specifically, melphalan binds to proteins in the red blood cell membrane, leading to higher plasma concentrations in patients with lower hemoglobin. Likewise, since renal elimination contributes significantly to melphalan clearance (~ 40%), the presence of renal impairment also leads to higher concentrations. We previously identified lower hemoglobin and/or creatinine clearance as strong predictors of survival and toxicities after high dose melphalan and autologous transplant. Given this, we hypothesized that clinical variables, in particular, pre-treatment hemoglobin, could predict for outcomes after Flu/Mel140 and HSCT. We analyzed 67 consecutive patients who received Flu/Mel140. In addition to standard clinical parameters, hemoglobin (Hgb) and creatinine clearance (CrCl) on day -6 were obtained. Hemoglobin was grouped as low or high relative to the median (&lt;9.5 or ≥ 9.5 g/dL), and CrCl was divided into two groups (&lt; 60 or ≥ 60 ml/min). In the entire cohort, the median age was 57 (21-73) years, with most patients being female (n=37; 55.2%) and white (n=27; 40.3%) or African-American (n=16; 23.9%). Most patients were diagnosed with AML/MDS (n=27; 40.3%) or idiopathic myelofibrosis (n=14; 20.9%), and the median lines of prior therapy was 2 (0-7). Prior to HSCT, 36 (53.7%) patients presented with intermediate disease risk index (DRI) and 19 (28.4%) with high DRI, while 31 (62%) patients had a high hematopoietic cell transplantation-specific comorbidity index (HCT-CI) score. Thirty (45.5%) patients received a matched related donor transplant, while 31 (47%) received a matched unrelated donor transplant. The median time to neutrophil and platelet engraftment was 15 (9-26) and 16 (8-104) days, respectively. The median overall survival (OS) was significantly shorter in patients with a lower Hgb (113 vs. 2536 days; p=0.004). This difference was attributed to an increased rate of transplant-related mortality (TRM) in patients with a lower Hgb (n=26; 81.3%) versus a higher Hgb (n=11; 36.7%) (p=0.0005). Time to relapse between patients with a lower and higher Hgb was not different (p=0.89). The median OS in patients with a lower CrCl was significantly worse (75 vs. 317 days; p=0.003). The rate of TRM was also found to be significantly worse in patients with a lower CrCl (n=10; 90.1%) compared to patients with a higher CrCl (n=27; 52.9%) (p=0.0023). Time to relapse was not different between patients with a lower and higher Cr Cl (p=0.29). Patients with both a low Hgb and CrCl experienced a shorter median OS (75 days vs. not reached; p&lt;0.0001; Figure 1). Multivariate Cox proportional hazards model with adjustment for clinical and prognostic factors found that a higher Hgb strongly predicted for better OS (HR 0.12, 95% CI 0.03-0.52; p=0.004) and less TRM (HR 0.13, 95% CI 0.03-0.53; p=0.004). The combination of a higher Hgb and CrCl ≥ 60 ml/min predicted for better OS (HR 0.08, 95% CI 0.01-0.63; p=0.017) and trended towards a decreased rate of TRM (HR 0.16, 95% CI 0.02-1.43; p=0.102). We then analyzed regimen-related toxicities among patients with a lower and higher Hgb and lower and higher CrCl. In patients with a lower hemoglobin, the median duration of hospitalization (35 vs. 29 days; p=0.02) and the mean duration of diarrhea (14.6 vs. 7.2 days; p=0.008) were significantly longer. In patients with a lower CrCl, the median duration of hospitalization (40 vs. 29 days; p=0.06) and the mean duration of diarrhea (20.9 vs. 8.6 days; p=0.0009) were longer, and the rate of infection was higher (90.9% vs. 49.1%; p=0.02). We show for the first time that pre-treatment Hgb and CrCl represent important determinants of clinical outcomes after Flu/Mel140 and HSCT. A lower hemoglobin in particular was strongly associated with a shorter OS and TRM. This is consistent with PK studies showing increased melphalan exposure in patients with low Hgb and CrCl. We conclude that consideration of clinical factors that affect melphalan exposure and implementation of PK-directed dosing may be beneficial in achieving optimal outcomes in patients receiving FluMel140 and HSCT. Figure Disclosures Galvin: Incyte: Consultancy. Patel:Celgene: Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Janssen: Speakers Bureau.

Insights into the variability of nasal potential difference, a biomarker of CFTR activity

BackgroundNasal potential difference (NPD) is used to evaluate CFTR function in vivo. We aimed to evaluate the intrasubject and intersubject variability of NPD measurements. MethodsWe reviewed NPD tracings of 116 patients with CF enrolled in the placebo arm of a multicenter study. Patients carried at least one nonsense mutation and underwent repeated NPD tests every 16 weeks. NPD parameters included basal potential difference (basal PD), inhibition of sodium absorption by amiloride (Δ Amiloride), chloride (Cl−) transport in response to a Cl−-free solution (Δ Low Cl−), isoproterenol (Δ Isoproterenol), the sum of Δ Low Cl− and Δ Isoproterenol (Δ Low Cl−-Isoproterenol) and ATP (Δ ATP). ResultsBasal PD and Δ Amiloride displayed the highest variabilities, mainly stemming from intercenter and intrasubject effect. Δ Low Cl−, Δ Isoproterenol and Δ Low Cl−-Isoproterenol demonstrated a large intrasubject variability but a smaller intersubject variability. The intrasubject measurement variability for Δ Low Cl−-Isoproterenol, was within ± 7.2 mV with 95% probability. It was greater in patients reporting ongoing pulmonary exacerbations. ConclusionsThe large intercenter variability of basal PD and Δ Amiloride highlights the operator-dependent aspect of these measurements. A difference greater than 7.2 mV in Δ Low Cl−-Isoproterenol in a given patient on CFTR modulator can be attributed, with 95% probability, to a treatment effect rather than to the variability inherent in the measurement.