Simultaneous Infrared Spectroscopy, Raman Spectroscopy and Luminescence Sensing: A Multi-Spectroscopic Analyti-cal Platform

Scientific questions in fields such as catalysis, monitoring of biological processes or environmental chemistry demand for analytical technologies combining orthogonal spectroscopies. Combined spectroscopic concepts facilitate in-situ on-line monitoring of dynamic processes providing for a better understanding of the involved reaction pathways. In the present study, a low-liquid-volume multi-spectroscopic platform was developed based on infrared attenuated total reflection (IR-ATR) spectroscopy combined with Raman spectroscopy and lumines-cence sensing. For demonstrating the measurement capabilities, exemplary analyte systems including water / heavy water and aqueous solutions of ammonium sulfate were analyzed as proof-of-principle studies. It was successfully demonstrated that three optical techniques may be integrated into a single analytical platform with-out interference providing synchronized and complementary datasets by probing the same minute sample vol-ume. In addition, the developed assembly provides a gas-tight lid sealing the headspace above the probed liq-uid for monitoring the concentration of molecular oxygen also in the gas phase via luminescence quenching. Hence, the entire assembly may be operated at inert conditions, as required for example during the analysis of photocatalytic processes.

Brief communication: Plasma cortisol concentration is affected by lactation, but not intra-nasal oxytocin treatment, in beef cows

In mammals, including sheep and mice, lactation attenuates the hypothalamo-pituitary-adrenal axis and plasma cortisol concentration. Oxytocin, one neuropeptide present in the blood during lactation, may contribute to such stress attenuation. Providing oxytocin intra-nasally increases plasma oxytocin concentration in cattle and can be used in non-lactating cows to mirror plasma oxytocin concentration of lactating cows. Therefore, our hypothesis was that there would be no difference in plasma cortisol between non-lactating beef cows intra-nasally administered oxytocin and lactating beef cows intra-nasally treated with saline. Twenty Bos taurus cows were randomly allocated by lactational status to one of four treatments, in a 2×2 factorial arrangement: 1) Non-lactating, saline (NL-S; n = 5); 2) Non-lactating, oxytocin (NL-OXT; n = 5); 3) Lactating, saline (L-S; n = 5); and 4) Lactating, oxytocin (L-OXT; n = 5). Two hours pre-treatment, cows were catheterized, moved to their appropriate chute and baseline blood samples were collected at -60, -45, -30, and 0 minutes before treatments were administered. Directly following the 0-minute sample, cows were administered their intra-nasal treatment via a mucosal atomization device. Subsequently, blood was collected at 2, 4, 6, 8, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, and 120 minutes. Non-lactating cows had greater (P = 0.02) plasma cortisol concentration compared with lactating cows. There was no lactation by treatment interactions for either plasma cortisol (P = 0.55) or oxytocin (P = 0.89) concentration. Although a treatment by time interaction was identified for oxytocin (P < 0.0001), there was no main effect of lactation on plasma oxytocin concentration (P = 0.34). Similar oxytocin and dissimilar cortisol concentration in lactating and non-lactating cows indicate that oxytocin alone cannot be responsible for reduced plasma cortisol in lactating ruminants. Further investigations are needed to elucidate alternative mechanisms that may be involved in the stress hypo-responsive condition of lactating mammals.

What is the Value of the 60 Minute Cortisol Measurement in the Short Synacthen Test (SST)? Evidence for the Defence

The Short Synacthen Test is the way that we most often determine whether people’s adrenal glands are working. We here have shown that an extra blood sample taken at 60 minutes post Synacthen vs a 30 minute sample alone, may make the test more effective at excluding those people who do not need to go on hydrocortisone supplementation or need further evaluation.

Effect of disdrometer sampling area and time on the precision of precipitation rate measurement

Due to the discretized nature of rain, the measurement of a continuous precipitation rate by disdrometers is subject to statistical sampling errors. Here, Monte Carlo simulations are employed to obtain the precision of rain detection and rate as a function of disdrometer collection area and compared with World Meteorological Organization guidelines for a one-minute sample interval and 95 \\% probability. To meet these requirements, simulations suggest that measurements of light rain with rain rates R &amp;leq; 0.50 mm h−1 require a collection area of at least 6 cm × 6 cm, and for R > 1 mm h−1, the minimum collection area is 10 cm × 10 cm. For R = 0.01 mm h−1, a collection area of 2 cm × 2 cm is sufficient to detect a single drop. Simulations are compared with field measurements using a new hotplate device, the Differential Emissivity Imaging Disdrometer. The field results suggest an even larger plate may be required to meet the stated accuracy, although for reasons that remain to be determined.

Evaluating the Low-Dose ACTH Stimulation Test in Neonates: Ideal Times for Cortisol Measurement

Context Low-dose adrenocorticotropic hormone stimulation testing (LDST) can be used to diagnose central adrenal insufficiency. However, uncertainty remains over optimal times to draw serum cortisol levels. Objective To determine optimal times to draw serum cortisol levels for the LDST in neonates. Design A retrospective chart review of LDSTs performed on neonates from January 1, 2009 to September 30, 2017. Setting Children’s Hospital of Eastern Ontario (CHEO), a tertiary-care outborn pediatric center. Patients Forty-nine patients were included: 23 (46.9%) born at term, 12 (24.5%) born very preterm to late preterm, and 14 (28.6%) born extremely preterm. Intervention Cortisol levels were drawn at baseline and 15, 30, and 60 minutes following administration of Cortrosyn 1 mcg/kg (maximum dose 1 mcg). Main Outcome Measure Timing of peak cortisol level and marginal value of drawing a second and third cortisol sample at 15, 30, or 60 minutes was determined. Results Cortisol peaked at 15-, 30-, and 60-minute sampling times for 4%, 27%, and 69% of patients, respectively. The probability that a failed LDST changes to a pass by adding a 15- or 30-minute sample to the superior 60 minute sample is 5.6% (1% to 25.8%) and 11% (3.1% to 32.6%), respectively, for a cortisol pass threshold of 18.1mcg/dL (500 nmol/L). Conclusions In contrast to studies of older children, we found that the majority of neonatal LDST cortisol peaks occurred at the 60-minute sampling time with the addition of a 30-minute sample providing substantial benefit. It is questionable if a 15-minute sample provides any benefit, making a case to revise LDST protocols to sample cortisol later for neonates.

Bleaching correction for DNA-measurements in highly diluted solutions using confocal microscopy

Precise and reliable determination of the nucleic acid concentration in biological samples still remains a challenge. This is particularly since the established fluorescene-based methods provide insufficient results, when only minute sample quantitites are available for analysis. Among other effects, photobleaching is the main reason for this. Since large molecules diffuse more slowly than small molecules, they are exposed to more excitation cycles and therefore have a higher probability of permanently losing their fluorescence. Solutions with large molecules hence show a reduced fluorescence. In this paper we present a method to correct this effect and thus allow high-precision sample concentration determination in minute sample quantities (< 2 µl drops with concentrations < 20 pg/µl). For this purpose, we used confocal microscopy with single molecule sensitivity. In the first step, we derived calibration curves from DNA solutions with defined fragment length. We analyzed dilution series over a wide concentration range (1 pg/µl – 1000 pg/µl) and measured their specific diffusion coefficients by employing fluorescence correlation spectroscopy. Using this information, we correct the measured fluorescence intensity of the calibration solutions for photobleaching effects. Subsequently, we evaluated our method by analyzing a series of DNA mixtures of varying composition.

Endogenous prostanoids influence on bile secretion in different groups of rats

In acute experiments on different age group of 30 white wild-type rats: juvenile (weight 130–175 g), mature (weight 200–250 g) and old (weight 300 g and more) we were investigated the changes in the volume rate of bile secretion with cyclooxygenase inhibition by acetylsalicylic acid (100 mkg/kg weight of animal) which is a blocker of the prostaglandin synthesis enzyme. We explored the changes of the level of choleresis and bile biochemical components by thin-layer chromatography In vivo. The relative abundances of cholecycle, henodeoxycholic, taurocholic and glycocholic bile acids in the liver of rats were determined by chromatography, with the subsequent densitometry. The biliary acid flow rate was calculated as the sum of the bile acid concentration multiplied by the volume of secreted biliary in one relevant thirty-minute sample. The conjugation coefficients were calculated for each thirty minute sample. Reduction of bile secretion by endogenous prostanoids was shown, because inhibition of prostaglandins synthesis caused the hypercholeresis on 42–112,5 % in different rat age groups, compared to control. Endogenous prostaglandins suppressed the processes of conjugation in old and juvenile age group on 117–189,1 %, in contrast these regulators have no significant effect on bile acids association with glycine and taurine in mature rats. The binding of endogenous prostanoids probably increased the conjugation processes in juvenile rats, whereas in the old experimental group acetylsalicylic acid was significantly reduced by 123 % on average. Analysis of changes in free and conjugated bile acids in the rats of different age groups showed that the ratio of qualitative changes in structure of the liver bile in rats with the cyclooxygenase blockade is mainly due to enhanced synthesis of free bile acids de novo. Therefore, endogenous prostanoids affect in the opposite way. There are have multi-directional impact on bile secretion in different age groups of rat that means ambiguous role of these drugs in liver function regulation at different stages of ontogenesis.

Not All About the Effort? A Comparison of Playing Intensities During Winning and Losing Game Quarters in Basketball

Purpose: To compare peak and average intensities encountered during winning and losing game quarters in basketball players. Methods: Eight semiprofessional male basketball players (age = 23.1 [3.8] y) were monitored during all games (N = 18) over 1 competitive season. The average intensities attained in each quarter were determined using microsensors and heart-rate monitors to derive relative values (per minute) for the following variables: PlayerLoad, frequency of high-intensity and total accelerations, decelerations, changes of direction, jumps, and total inertial movement analysis events combined, as well as modified summated-heart-rate-zones workload. The peak intensities reached in each quarter were determined using microsensors and reported as PlayerLoad per minute over 15-second, 30-second, 1-minute, 2-minute, 3-minute, 4-minute, and 5-minute sample durations. Linear mixed models and effect sizes were used to compare intensity variables between winning and losing game quarters. Results: Nonsignificant (P > .05), unclear–small differences were evident between winning and losing game quarters in all variables. Conclusions: During winning and losing game quarters, peak and average intensities were similar. Consequently, factors other than the intensity of effort applied during games may underpin team success in individual game quarters and therefore warrant further investigation.