CL Measurements Research Articles

Predictive Accuracy of Three Dimensional Ultrasound Measurement of Fetal Adrenal Gland Volume in Preterm Labor Cases

Abstract Background Preterm birth is one of the major clinical problems in obstetrics and neonatology as it is associated with perinatal mortality, serious neonatal morbidity and in some cases childhood disability. It is reported that more than 80% of all neonatal mortality and morbidity is due to preterm birth. Objective In this study fetal adrenal gland volume and fetal zone measurement were used as a predictors for occurrence of labor in singleton pregnancies complicated by threatened preterm labor in comparison to cervical length and cervicovaginal fetal fibronectin. Methodology The study was carried out at Ain Shams University Maternity Hospital. The current study include 88 pregnant women who presented with symptoms or signs of threatened preterm labor (PTL). All women were subjected to full history taking, full general, abdominal, pelvic examination, in addition to ultrasound fetal biometry, measurement of cervical length, measurement of fetal fibronectin, fetal adrenal gland volume AGV and fetal zone acquisitions. Results Our results showed high statistically significant difference between the two groups of women regarding CL measurement, FZE and cAGV with P values < 0.001 suggesting that ultrasound examination of fetal adrenal gland and assessment of FZE at time of evaluation for symptoms of PTL may be clinically beneficial in predicting the occurrence of labor in pregnant women at risk of preterm labor. Conclusion Our results demonstrate that in women presenting with threatened preterm labor, cAGV and FZE measured by 3-dimensional ultrasound seem to be significant predictors of delivery within 7 days, when compared to CL and cervicovaginal fetal fibronectin.

931: Mid-trimester cervical length screening: effect of poorly-developed lower uterine segment on pregnancy outcome

Poorly developed lower segment (PDLUS) is characterized by a long “cervix” (> ∼5 cm), S-shaped canal, different echogenicties in the “cervix”, increased bladder-to-amniotic cavity distance, and “internal os” cephalad to the inferior edge of the bladder reflection (Figure). PDLUS precludes accurate CL measurement as the location of the true internal os is obscured. PDLUS is protective against sPTB in women with a prior sPTB < 34 weeks. Whether PDLUS affects gestational length in low-risk women is unknown. Retrospective cohort study of women with singletons and no prior sPTB who had mid-trimester transvaginal CL screening, 1/2016-8/2018; fetal anomalies were excluded. We compared birth gestational age (GA) between women with a measured (Normal) CL ≥ 25mm versus PDLUS. A sample of 1135 with a Normal:PDLUS ratio of 4:1 had 80% power to detect a 1/2-wk difference in birth GA (ɑ=.05, GA SD=2.4 wks). Secondary outcomes included sPTB < 37 wks, preterm labor (PTL) evaluations, and a Cox survival model that examined time from CL scan to delivery. Indicated PTBs were censored at birth, and to account for elective inductions ≥39 wks, we censored the time at 39.0 wks. 990 (79%) women with Normal CL and 265 (21%) with PDLUS were included. Characteristics were comparable (Table) but multiparity was more common in PDLUS; age and BMI were different but not clinically significant. Birth GA was 38.7±2.4 wks with Normal vs 38.9 ± 2.0 wks with PDLUS (p=0.10); 19% with Normal CL had ≥ 1 PTL evaluation vs. 17% with PDLUS (p=0.54), and at a similar GA for the initial visit (31±4.8 wks vs 30±5.4 wks, p=0.36). In the Cox model, PDLUS was found to have a significantly lower hazard ratio (HR) of 0.67 (95% CI 0.46, 0.98; p=0.04) for earlier birth. After controlling for parity, the HR fell to 0.64 (p=0.02). The incidence of sPTB < 37 wk was 3.6% for Normal CL and 1.1% for PDLUS (p=0.04). PDLUS observed at mid-trimester CL screening in low-risk women was associated with a significantly lower rate of sPTB < 37 wk and a lower HR for earlier birth.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

36Cl preparation method for Chinese Karst samples (Tiankeng)

Tiankeng, a typical Karst relief of the Late Quaternary Period, in the south of China, plays an important role when researching the surface shape and evolution of the Karst relief. The accumulation of Chlorine-36 (T1/2 = 301 ka) through the interaction of cosmic ray particles with Ca, K and Cl in rocks allow it to be used as the ideal nuclide for determination of the exposure age and erosion rate of limestone. In this work, an improved 36Cl sample preparation method for Tiankeng limestone was presented. The Isotope Dilution-AMS technique allows for the simultaneous measurement of 36Cl and Cl with a single AMS sample preparation. The barium introduced during the sample preparation was removed to avoid ionizer poisoning and attain a higher and more stable beam current. The method is particularly suitable for limestone samples, as well as for soil, sediment and water samples.

A four-electrode method to study dynamics of ion activity and transport in skeletal muscle fibers.

Ion movements across biological membranes, driven by electrochemical gradients or active transport mechanisms, control essential cell functions. Membrane ion movements can manifest as electrogenic currents or electroneutral fluxes, and either process can alter the extracellular and/or intracellular concentration of the transported ions. Classic electrophysiological methods allow accurate measurement of membrane ion movements when the transport mechanism produces a net ionic current; however, they cannot directly measure electroneutral fluxes and do not detect any accompanying change in intracellular ion concentrations. Here, we developed a method for simultaneously measuring ion movements and the accompanying dynamic changes in intracellular ion concentrations in intact skeletal muscle fibers under voltage or current clamp in real time. The method combines a two-microelectrode voltage clamp with ion-selective and reference microelectrodes (four-electrode system). We validate the electrical stability of the system and the viability of the preparation for periods of ∼1 h. We demonstrate the power of this method with measurements of intracellular Cl-, H+, and Na+ to show (a) voltage-dependent redistribution of Cl- ions; (b) intracellular pH changes induced by changes in extracellular pCO2; and (c) electroneutral and electrogenic Na+ movements controlled by the Na,K-ATPase. The method is useful for studying a range of transport mechanisms in many cell types, particularly when the transmembrane ion movements are electrically silent and/or when the transport activity measurably changes the intracellular activity of a transported ion.

CLARITY analysis of the Cl/pH sensor expression in the brain of transgenic mice

Genetically encoded biosensors are widely used in cell biology for the non-invasive imaging of concentrations of ions or the activity of enzymes, to evaluate the distribution of small molecules, proteins and organelles, and to image protein interactions in living cells. These fluorescent molecules can be used either by transient expression in cultured cells or in entire organisms or through stable expression by producing transgenic animals characterized by genetically encoded and heritable biosensors. Using the mouse Thy1 mini-promoter, we generated a line of transgenic mice expressing a genetically encoded sensor for the simultaneous measurements of intracellular Cl− and pH. This construct, called ClopHensor, consists of a H+- and Cl−-sensitive variant of the enhanced green fluorescent protein (E2GFP) fused with a red fluorescent protein (DsRedm). Stimulation of hippocampal Schaffer collaterals proved that the sensor is functionally active. To reveal the expression pattern of ClopHensor across the brain of Thy1::ClopHensor mice, we obtained transparent brain samples using the CLARITY method and imaged them with confocal and light-sheet microscopy. We then developed a semi-quantitative approach to identify brain structures with high intrinsic sensor fluorescence. This approach allowed us to assess cell morphology and track axonal projection, as well as to confirm E2GFP and DsRedm fluorescence colocalization. This analysis also provides a map of the brain areas suitable for non-invasive monitoring of intracellular Cl−/pH in normal and pathological conditions.This article is part of a Special Issue entitled: Honoring Ricardo Miledi - outstanding neuroscientist of XX-XXI centuries.

125Iodide as a Surrogate for 36Chloride in Tracing Transepithelial Intestinal Chloride Transport

Chloride (Cl−) transport by the large intestine is critically important, driving epithelial fluid secretion and absorption. Dysregulation of Cl− transport by the intestine results in diarrhea‐associated pathologies. Measurement of epithelial Cl− transport has long been achieved using the radioisotope 36Cl−. However, the price of 36Cl has sky‐rocketed, now costing over $100 per μCi compared to just $1.50 per μCi 15 years ago, making it prohibitively expensive and a barrier to future research. 125Iodide (125I−) has been used as an alternative to 36Cl− in some transport assays, including Cl− efflux and influx by cultured cells, but has never before been validated in parallel with 36Cl as an alternative for tracing transepithelial Cl− transport. The goal of this study was to examine whether 125I− can serve as a reliable surrogate for measuring Cl− transport by the intestinal epithelium. Under symmetrical short‐circuited conditions in the Ussing chamber, we simultaneously measured 36Cl− and 125I− fluxes across the cecum and distal colon from mice lacking the main Cl−/HCO3− exchanger, DRA (Slc26a3), relative to wild‐type controls. In addition, we used a cocktail of forskolin and 3‐isobutyl‐1‐methylxanthine (IBMX) to stimulate cAMP production and net Cl− secretion by these tissues. We found the unidirectional fluxes of 125I− correlated well with 36Cl− in all circumstances, even in the absence of DRA, with a significant R2 value of 0.86 across all fluxes, or higher (up to 0.93) when data was separated by genotype and intestinal segment. Unexpectedly, cAMP induced net Cl− secretion predominantly through a reduction in the absorptive, mucosal‐to‐serosal, Cl− flux rather than stimulating the secretory serosal‐to‐mucosal Cl− flux, which is noteworthy considering antidiarrheal drugs often target secretory processes. Also, rates of Cl− and I− absorption in DRA‐knockout mice were decreased by 79% and 50%, respectively, in the ceca, and 65% and 34% in the distal colon, suggesting this Cl− transporter may have a previously unrecognized role in I− uptake. In summary, we demonstrated 125I− is an adequate, cost‐effective alternative for tracing unidirectional Clfluxes across the intestinal epithelium. For example, the amount of 36Cl− used in this study cost $536 compared to a mere $4 worth of 125I−, thus making future research into epithelial Cltransport accessible. In addition, this study also provides insight into mechanisms of net Clsecretion and suggests that DRA may have a role in intestinal I− absorption.Support or Funding InformationThis study was supported by grants DK088892 and DK108755 to M. Hatch from the National Institutes of Health.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

125 Iodide as a surrogate tracer for epithelial chloride transport by the mouse large intestine in vitro.

What is the central question of this study? The tracer 36 Cl- , currently used to measure transepithelial Cl- fluxes, has become prohibitively expensive, threatening its future use. 125 Iodide, previously validated alongside 36 Cl- as a tracer of Cl- efflux by cells, has not been tested as a surrogate for 36 Cl- across epithelia. What is the main finding and its importance? We demonstrate that 125 I- can serve as an inexpensive replacement for measuring Cl- transport across mouse large intestine, tracking Cl- transport in response to cAMP stimulation (inducing Cl- secretion) in the presence and absence of the main gastrointestinal Cl- -HCO3- exchanger, DRA. Chloride transport is important for driving fluid secretion and absorption by the large intestine, with dysregulation resulting in diarrhoea-associated pathologies. The radioisotope 36 Cl- has long been used as a tracer to measure epithelial Cl- transport but is prohibitively expensive. 125 Iodide has been used as an alternative to 36 Cl- in some transport assays but has never been validated as an alternative for tracing bidirectional transepithelial Cl- fluxes. The goal of this study was to validate 125 I- as an alternative to 36 Cl- for measurement of Cl- transport by the intestine. Simultaneous fluxes of 36 Cl- and 125 I- were measured across the mouse caecum and distal colon. Net Cl- secretion was induced by the stimulation of cAMP with a cocktail of forskolin (FSK) and 3-isobutyl-1-methylxanthine (IBMX). Unidirectional fluxes of 125 I- correlated well with 36 Cl- fluxes after cAMP-induced net Cl- secretion, occurring predominantly through a reduction in the absorptive mucosal-to-serosal Cl- flux rather than by stimulation of the secretory serosal-to-mucosal Cl- flux. Correlations between 125 I- fluxes and 36 Cl- fluxes were maintained in epithelia from mice lacking DRA (Slc26a3), the main Cl- -HCO3- exchanger responsible for Cl- absorption by the large intestine. Lower rates of Cl- and I- absorption in the DRA knockout intestine suggest that DRA might have a previously unrecognized role in iodide uptake. This study validates that 125 I- traces transepithelial Cl- fluxes across the mouse large intestine, provides insights into the mechanism of net Cl- secretion and suggests that DRA might be involved in intestinal iodide absorption.

Parameters dependent synthesis of zinc stannate nanowires using CVD and its porphyrin dye loaded optical studies

Polycrystalline zinc stannate (Zn2SnO4) nanowires have been studied for its synthesis optimization using novel carbothermal catalytic method, wherein binary oxide precursors were used under inert atmosphere at variable CVD synthesis parameters. X-ray diffraction, FESEM, EDS, HRTEM, Raman and CL measurements are used to understand the typical behaviour of ternary metal oxide nanowires i.e. Zn2SnO4 growth. The optimization of Zn2SnO4 nanowires has been discussed via synthesis parameters followed with reaction equations corresponding to its optical and room temperature electrical properties. Further, its visible range sensitization has been demonstrated for suitable sample using zinc tetra phenyl porphyrin (ZnTPP) dye via dye adsorption method. Corresponding optical and IPCE studies of photo-electrodes shows broadened visible range absorption in 300–600 nm range and conversion efficiency of 28% (at ∼447 nm) for the nanowires having indirect band gap of ∼3.4 eV. This study opens up the potential application in photovoltaic, sensors and photo catalytic devices.

Characteristics of submicron particles coming from a big firecrackers burning event: Implications to atmospheric pollution

Firecrackers burning on different occasions all over the world is a short-term big source of fine particles and their precursors in the air. This study presents the real-time changes in concentrations, composition and characteristics of non-refractory particulate matter smaller than 1 μm aerodynamic diameter (NR-PM1), and black carbon (BC) during the Diwali festival, when a huge amount of firecrackers are burnt in India. Online measurements (1 min integration time) of organics, SO42−, NO3−, NH4+, and Cl− were performed using high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS), and that of BC with seven wavelength aethalometer over a big urban city (Ahmedabad, 23.0ºN, 72.6ºE) in western India. A sharp increase (3–23 times higher) in the concentrations of all the measured species was observed on the evening of the Diwali that persisted overnight due to a combination of primary emissions and secondary formation of aerosol. Organics were the dominant contributor (∼85%) followed by SO42− (∼13%), Cl− (∼4%), NO3− (∼4%) and NH4+ (∼2%) to NR-PM1 on the Diwali night. Further, variations in H/C and O/C ratios before, during and after the Diwali suggest fresh emissions of primary organics on the Diwali night, and highly oxidized secondary organic formation on the next day. Aerosol neutralization ratio (ANR, defined as the molar ratio of NH4+ to sum of SO42−, NO3− and Cl−), an indicative of aerosol acidity, reduced to as low as 0.1 on the Diwali night, which has implications to short-term acute atmospheric air pollution.

The patient with metabolic alkalosis

ABSTRACTMetabolic alkalosis defined by the increase of both plasma HCO3- level (>26 mmol/L) and blood arterial pH (>7.43) is quite frequent and usually accompanied by hypokalemia. Its pathogenesis requires both the generation of alkalosis and its maintenance. Generation may be due to excessive hydrogen ion loss by the gastrointestinal tract (e.g. vomiting) or by the kidney (e.g. use of loop diuretics) or may be due to exogenous base gain. Maintenance reflects the inability of the kidney to excrete the excess of bicarbonate because of hypovolemia, chloride depletion, hypokalemia, hyperaldosteronism, renal failure or a combination of these factors. The evaluation of volemic status and measurement of urinary Cl- and plasma levels of renin and aldosterone are crucial to identify the cause(s) of metabolic alkalosis. The cornerstone of treatment is the correction of existing depletions and the prevention of further losses. In vomiting-induced chloride depletion alkalosis, infusion of potassium chloride restores the excretion of bicarbonate by the kidney.

Analytical performance evaluation of the new GEM® Premier™ 5000 analyzer in comparison to the GEM® Premier™ 4000 and the RapidPoint® 405 systems

Aim of the studyBlood gas analysis (BGA) is essential for the diagnosis and management of acid-base imbalances. We evaluated and compared the analytical characteristics of the new GEM® Premier™ 5000 (GP5000) (Instrumentation Laboratory, Bedford, MA, United States) BGA point-of-care (POC) device with those of the GEM® Premier™ 4000 (GP4000) (Instrumentation Laboratory, Bedford, MA, United States) and RapidPoint® 405 (RP405) (Siemens Healthcare, Milan, Italy) POC analyzers. The effect of sample mixing on patient results was also studied. Material and methodsQuantitative measurement of pH, pCO2, pO2, Na+, K+, Cl−, iCa2+, glucose, lactate, tHb, COHb, MetHb, O2Hb, HHb and Hct were carried out. The imprecision study (IS) and method comparison study (MS) were performed according to CLSI EP guidelines, using respectively internal as well as external quality controls (IS) and whole blood samples collected from the routine analysis (MS). ResultsGP5000 demonstrated satisfactory characteristics in the IS showing comparable (GM4000) or even better (RP405) imprecision results than the routine POC devices. Good performance was observed in the MS both using GP4000 and RP405 as reference instruments. Pre-analytical sample management can heavily affect the accuracy of BGA results. In the specimen mixing evaluation, a significant improvement in results accuracy was observed when mixing procedures were more meticulous. ConclusionsConsidering the overall analytical performance observed, the ease of use of the system, the rapid time-to-results and the innovative Intelligent Quality Management technology (iQM2®), GP5000 seems suitable to be used in clinical care for safe patient management. Additionally, effective sample mixing upon draw and before analysis is strongly advisable in order to ensure the most clinically reliable BGA results.

Significance of OH, F and Cl content in biotite during metamorphism of the Western Adamello contact aureole

The hydroxyl (O(4)) site composition of biotite can in principle be used to retrieve information about fluid composition during fluid–rock interaction; however, due to low F and Cl content, as well as difficulties involved with analyzing the H2O content using in situ techniques, measuring these species in biotite has remained an elusive goal. Here we present high-precision secondary ion mass spectrometry (SIMS) OH–F–Cl measurements from biotite within metapelites from the Western Adamello Tonalite (WAT) contact aureole, Northern Italy. Fluorine, chlorine and hydrogen are analyzed on the SIMS sequentially by peak-hopping at the same biotite spot; H2O, F and Cl content were measured with a precision (1σ) οφ 0.06 ωτ%, 50 ανδ 5 ππµ, ρeσπeχτιϖeλψ. The compositions of isolated biotite crystals in andalusite are compared with that of biotite in the matrix, documenting that halogens and H2O behave refractory in biotite during the time scale of contact metamorphism. The H2O and halogen contents of biotite are mostly locked in during the prograde to peak formation of biotite, and are not reset during further heating or cooling, unless significant biotite recrystallization occurs. It also appears that both Ti content and XMg of the biotite from the Western Adamello contact aureole were not significantly reset during cooling. The concentration of F and Cl does not vary systematically with metamorphic grade, which indicates that these species reflect initial compositions. No significant Rayleigh fractionation behavior was observed for these elements. H2O variations in the biotite from samples throughout the Western Adamello contact aureole suggest that Al-oxy substitution partially controls the variations in OH content through charge balance of the type R2+,VI + OH− = Al3+,VI + O2− + H2, while the Ti-oxy substitution does not seem to influence the O(4) site occupation. The main titanium substitution appears to be the Ti-vacancy ( $${\text{2}}{{\text{R}}^{{\text{2}}+}}~=~{\text{T}}{{\text{i}}^{{\text{4}}+}}~+\,{\square ^{{\text{VI}}}}$$ ) exchange. Variations in H2O and halogen concentrations in biotite define sub mm-scale areas of localized equilibration, even for biotite recrystallized during dehydration reactions that produced large amounts of fluid (chlorite or muscovite breakdown). Similar systematics were observed for Ti4+ and Al3+. These findings further support the increasing number of observations that kinetics control much of the mineralogical reactions occurring in contact aureoles, and hence care is advised in using equilibrium thermodynamics in this environment.

Change in pH and Chloride Concentration inside Crevice of Stainless Steels

Stainless steels sometimes suffer from crevice corrosion in chloride environments. The pH value and Cl- concentration are important factors in the initiation and growth of crevice corrosion. Nishimoto et.al.[1] fabricated a glass plate with a sol-gel SiO2 sensing layer, which contains a pH indicator and a Cl- sensitive florescent dye, and the pH and Cl- distributions in the crevice solution for stainless steel were visualized simultaneously. The specimens used in this study were cut from a Type 430 stainless steel sheet (0.035%C, 0.20%Si, 0.38%Mn, 0.019%P, 0.005%S, 0.19%Ni, 15.9%Cr in mass%). The specimens were heat-treated at 1123 K for 600 s and water-cooled. The size of the specimen was 4 mm×3 mm×20 mm. The specimen surfaces were polished by a 1 μm diamond past. To fabricate the sensing plate for the simulations measurements of pH and Cl- concentration, Terbium-dipicolinic acid complex (Tb-DPA) and quinine sulfate as the fluorescent dyes were chosen. Tb-DPA was used as the sensing dye for the pH measurements, and quinine sulfate was used to measure the Cl- concentration. Tb-DPA was formed by mixing Tb­­2(SO4)3 and dipicolinic acid. A sol-gel method was used to make the sensing layer, which contained two fluorescent dyes, onto one side of a quartz glass plate. Figure 1 shows the illustration of a crevice corrosion test cell. In crevice corrosion tests, the crevice was formed between the sensing plate and specimen. Potentiostatic polarization was performed at 0.15 V (vs. Ag/AgCl, 3.33 M KCl) in 10 mM NaCl (pH 3.0). During crevice corrosion tests, the surface images of the specimen were taken under UV irradiation, and pH and Cl- values were calculated from the fluorescence images. The details were described in the literature. [1] Figure 2 shows the surface appearance and the images of pH and Cl- distributions at the initiation point of the crevice corrosion at 1500 s. The pH and Cl- were calculated by the brightness of fluorescence images. A pit was initiated inside the crevice. Before the initiation of crevice corrosion, it was elucidated that the pH at the initiation point of gradually decreased with time, and that the Cl- concentration increased with time. On the basis of time variations of the pH and Cl- concentration, the initiation and growth mechanims of the crevice corrosion of stainales steels were determiend. References; Nishimoto, J. Ogawa, I. Muto, Y. Sugawara, N. Hara: Corros. Sci., 106, 298-302(2016) Figure 1

Light-Driven Chloride Transport Kinetics of Halorhodopsin

Despite growing interest in light-driven ion pumps for use in optogenetics, current estimates of their transport rates span two orders of magnitude due to challenges in measuring slow transport processes and determining protein concentration and/or orientation in membranes in vitro. In this study, we report, to our knowledge, the first direct quantitative measurement of light-driven Cl− transport rates of the anion pump halorohodopsin from Natronomonas pharaonis (NpHR). We used light-interfaced voltage clamp measurements on NpHR-expressing oocytes to obtain a transport rate of 219 (± 98) Cl−/protein/s for a photon flux of 630 photons/protein/s. The measurement is consistent with the literature-reported quantum efficiency of ∼30% for NpHR, i.e., 0.3 isomerizations per photon absorbed. To reconcile our measurements with an earlier-reported 20 ms rate-limiting step, or 35 turnovers/protein/s, we conducted, to our knowledge, novel consecutive single-turnover flash experiments that demonstrate that under continuous illumination, NpHR bypasses this step in the photocycle.

A rapid and sensitive LC–MS/MS method for quantitative analysis of cardiolipin (18:2)4 in human leukocytes and mouse skeletal muscles

A rapid and sensitive LC–MS/MS method has been developed for quantitative analysis of cardiolipin (18:2)4 or CL (18:2)4 in human leukocytes and mouse mitochondria. The structural analog CL (14:0)4 was used as the internal standard. Both CL (18:2)4 and the IS were extracted using a modified Folch method, and separated on a Waters XBridge® BEH C18 XP column using a mobile phase of 0.1% ammonium hydroxide in acetonitrile/water (90:10, v/v) pumped at a flow rate of 0.4 mL/min. Quantitation was achieved by negative ESI-MS/MS in MRM mode. The total run time was 2.00 min with retention times of 0.74 min for the IS and 0.84 min for CL (18:2)4, respectively. The method was validated according to the US-FDA guidance for bioanalytical method validation using human leukemia and lymphoma cell lines, which had a calibration range of 0.120–60.2 nM with a correlation coefficient >0.999. The intra- and inter-assay accuracy and precision were ≤±5% and ≤8%. The IS normalized matrix factors of CL (18:2)4 and the IS normalized recoveries of CL (18:2)4 ranged 0.92–1.04, and 95–101%, respectively. The stability studies showed that CL (18:2)4 was stable under various test conditions. The developed method was successfully applied to the measurement of CL (18:2)4 in various biological samples including K562 and HL-60 human leukemia cell lines, U937 human lymphoma cell line, white blood cells from patients of Alzheimer’s disease and normal cognitive controls (NCCs), and mitochondria from mouse skeletal muscles. It may be useful for preclinical and clinical studies of this compound.

Photochemical controls on chlorine and bromine geochemistry at the Martian surface

Widely distributed perchlorate on the Martian surface and over three orders of magnitude variation in bromine abundances in surface samples are difficult to explain solely by chloride and bromide aqueous geochemistry. New experiments show that photochemical oxidation (ultraviolet wavelength 254 nm) of chloride- and bromide-bearing evaporative brines in the presence of silica beads produces substantial perchlorate (ClO−4), chlorate (ClO−3), and bromate (BrO−3) under conditions relevant to Mars. Neutral to alkaline aqueous environments result in the dominance of chlorate over perchlorate. Preferential atmospheric recycling of Br over Cl causes variable Br/Cl ratios, consistent with numerous in-situ measurements of Cl and Br abundances on Mars. Bromate reacts with organics more readily than chlorate or perchlorate, and its presence in subsurface brines could challenge habitability in the Martian subsurface.

Comparison of conventional fluid management with PVI-based goal-directed fluid management in elective colorectal surgery

Intraoperative fluid management is quite important in terms of postoperative organ perfusion and complications. Different fluid management protocols are in use for this purpose. Our primary goal was to compare the effects of conventional fluid management (CFM) with the Pleth Variability Index (PVI) guided goal-directed fluid management (GDFM) protocols on the amount of crystalloids administered, blood lactate, and serum creatinine levels during the intraoperative period. The length of hospital stay was our secondary goal. Seventy ASA I–II elective colorectal surgery patients were randomly assigned to CFM or GDFM for fluid management. The hemodynamic data and the data obtained from ABG were recorded at the end of induction and during the follow-up period at 1 h intervals. In the preoperative period and at 24 h postoperatively, blood samples were taken for the measurement of hemoglobin, Na, K, Cl, serum creatinine, albumin and blood lactate. In the first 24 h after surgery, oliguria and the time of first bowel movement were recorded. Length of hospital stay was also recorded. Intraoperative crystalloid administration and urine output were statistically significantly higher in CFM group (p < 0.001, p: 0.018). The end-surgery fluid balance was significantly lower in Group GDFM. Preoperative and postoperative Na, K, Cl, serum albumin, serum creatinine, lactate and hemoglobin values were similar between the groups. The time to passage of stool was significantly short in Group-GDFM compared to Group-CFM (p = 0.016). The length of hospital stay was found to be similar in both group. PVI-guided GDFM might be an alternative to CFM in ASA I–II patients undergoing elective colorectal surgery. However, further studies need to be carried out to search the efficiency and safety of PVI.

Measurement of Cl− : Br−Ratios in the Porewater of Clay-Rich Rocks—A Comparison of the Crush-and-Leach and the Paper-Absorption Methods

Characterization of porewater chemistry in low-permeability, clay-rich rocks provides insights into solute transport mechanisms and the origin and residence time of porewater. Extraction of porewater for chemical quantification is challenging, and several methods have been applied including squeezing, advective displacement, crush and leach, and a relatively new technique that extracts porewater by absorption into a cellulosic paper by capillary action. Here we compare porewater Cl−and Br−mass ratios from samples using the paper-absorption and crush-and-leach techniques. Samples were obtained from Upper Ordovician shales in the Michigan Basin in Ontario, the Opalinus Clay at the Mont Terri Rock Laboratory in Switzerland, and the Upper Ordovician Lorraine Group shale in southern Quebec. The data display consistent and reproducible differences among methods for Cl−and Br−mass ratios, with the paper-absorption method producing systematically lower Cl− : Br−ratios. The observed differences in Cl− : Br−ratios are attributed primarily to anion exclusion effects which are stronger for Br−than for Cl−, resulting in higher Br−concentrations in the largest pores that are preferentially sampled by the paper-absorption technique. In addition, calculations suggest that Cl−is more effective than Br−in forming ion pairs and clusters with neutral or positive charge which can enter the diffuse double layer. This causes a further decrease in the Cl− : Br−ratios for the mobile water. One important message from this work is that different extraction methods should not be expected to converge on a unique porewater Cl− : Br−ratio because each method reflects different proportions of the interlayer, diffuse double layer, and mobile fractions of porewater.

The angular power spectrum measurement of the Galactic synchrotron emission using the TGSS survey

AbstractCharacterizing the diffuse Galactic synchrotron emission (DGSE) at arcminute angular scales is needed to remove this foregrounds in cosmological 21-cm measurements. Here, we present the angular power spectrum (Cℓ) measurement of the diffuse Galactic synchrotron emission using two fields observed by the TIFR GMRT Sky Survey (TGSS). We apply 2D Tapered Gridded Estimator (TGE) to estimate the Cℓ from the visibilities. We find that the residual data after subtracting the point sources is likely dominated by the diffuse Galactic synchrotron radiation across the angular multipole range 240 ≤ ℓ ≲ 500. We fit a power law to the measured Cℓ over this ℓ range. We find that the slopes in both fields are consistent with earlier measurements. For the second field, however, we interpret the measured Cℓ as an upper limit for the DGSE as there is an indication of a significant residual point source contribution.

P01.03: Ultrasound assessment of cervical length and volume: comparison of transabdominal and transvaginal approach

We investigate the reliability of transabdominal (TA) 3D measurements of the cervical volume (CV) by comparison with transvaginal sonography for CV measurement. All singleton pregnancies were included and women who already had a diagnosis of preterm labour, PROM, IIOC in the current pregnancy were excluded. For determination of the CV using VOCAL software. We assessed the correlation of TA and TV measurements. In addition, the discrepancies between TA and TV sonography were analysed to investigate the practical usefulness of TA sonography for the variable maternal and fetal conditions. A paired t test and Pearson correlation were used to compare the two parameters according to approach method. A total of 300 pregnant women were enrolled in this study. The mean GA was 33±3.6 years. The mean CL and CV were 34.5 ± 9.5 cm and 35.1 ± 12.9cm3 on TAS and 33.5 ± 9.7 cm and 35.1 ± 12.9cm3 on TVS, respectively. There was no significant difference between these means of CL and CV(Pearson r = 0.76 vs r=0.91, respectively). There are no significant discrepancy between TV and TA measurement of both parameter for the variable fetal and maternal condition; fetal presentation, maternal abdominal wall thickness, bladder filling state, maternal age, amniotic fluid index. Preterm birth group (N=16, 7.4%) had more shorter and smaller TV CL, CV(30.0 ± 12.1mm vs 34.0 ± 0.93mm, p 0.01 and 29.30 ± 9.3 cm3 vs 35.47 ± 13.14 cm3 p 0.03, respectively) than term birth group. CV measurement did not add any benefit compared with the CL measurement for prediction of preterm birth. But in subgroup analysis, CV measurement had additional benefit compared with the CL for prediction of preterm birth in normal cervical length group. In conclusion, the evidence for the clinical application of cervical volume screening is still insufficient. If TA CL is normal, it could be useful to try the TACV measurement. This step-by-step approach may be more convenient and useful to both patients and physicians for cervical length screening.