Changes In Concentration Research Articles

Examining the effects of the HIV-1 protein Tat and morphine on antiretroviral accumulation and distribution within the brain.

Despite combination antiretroviral therapy effectively suppressing HIV within the periphery, neuro-acquired HIV (neuroHIV) remains a significant problem and approximately half of people living with HIV will experience HIV-associated neurocognitive disorders (HAND). Concurrent opioid use exacerbates neuroHIV by promoting neuroinflammation, neuronal injury and synaptodendritic culling, viral replication, and potentially altering antiretroviral concentrations within the brain. The present study examined the effects of HIV and morphine co-exposure on the accumulation and spatial distribution of antiretroviral drugs across multiple regions within the brain in an HIV-1 Tat transgenic mouse model by using infrared-matrix-assisted laser desorption electrospray ionization mass spectrometry imaging (IR-MALDESI MSI). Morphine exposure uniquely decreased antiretroviral concentrations in anterior cerebral (primary motor and somatosensory) cortices, corpus collosum (anterior forceps), caudoputamen, nucleus accumbens, and posterior regions including the hippocampus, corpus callosum (main body), cerebral cortex (somatosensory and auditory cortices), thalamus, and hypothalamus. Interestingly, male mice experienced greater morphine-associated decreases in antiretroviral concentrations than females. The study also assessed whether changes in antiretroviral concentrations were linked with inflammation in astroglia, assessed through the measurement of astroglial activation using glial fibrillary acidic protein (GFAP) as a marker. Alterations in antiretroviral concentrations co-registering with areas of astroglial activation exhibited sex-specific treatment differences. This study highlights the intricate interplay between HIV, opioids, and antiretroviral drugs within the CNS, elucidating distinct regional and sex variations in responsiveness. Our findings emphasize the identification of vulnerabilities within the neural landscape and underscore the necessity of carefully monitoring opioid use to maintain the efficacy of antiretroviral therapies.

Response of Circulating Free Cellular DNA to Repeated Exercise in Men with Type 1 Diabetes Mellitus

Background: Intense exercise leads to neutrophil extracellular traps (NETs) formation, which triggers cell disintegration. NET, as well as other processes of apoptosis, necrosis, and spontaneous secretion, result in increased levels of cell-free DNA (cf-DNA) in the circulation. An increment of cf-DNA is also observed in autoimmune diseases, such as type 1 diabetes mellitus (T1DM). Repeated exhaustive exercises are an impulse for physiological adaptation; therefore, in this case–control study, we compared the exercise-induced increase in cf-DNA in men with T1DM and healthy controls to determine the development of the tolerance to exercise. Methods: Volunteers performed a treadmill run to exhaustion at a speed matching 70% of their personal VO2 max at three consecutive visits, separated by a 72 h resting period. Blood was collected before and after exercise for the determination of plasma cell-free nuclear and mitochondrial DNA (cf n-DNA, cf mt-DNA) by real-time PCR, blood cell count and metabolic markers. Results: Each bout of exhaustive exercise induced a great elevation of cf n-DNA levels. An increase in cf mt-DNA was observed after each run. However, the significance of the increase was noted only after the second bout in T1DM participants (p < 0.02). Changes in cf-DNA concentration were transient and returned to baseline values during 72 h of resting. The exercise-induced increment in circulating cf n-DNA and cf mt-DNA was not significantly different between the studied groups (p > 0.05). Conclusions: Cf-DNA appears to be a sensitive marker of inflammation, with a lower post-exercise increase in individuals with T1DM than in healthy men.

Optimal Restoration of Spermatogenesis following Testosterone Therapy using hCG and FSH

To study improvements in spermatogenesis in men with a history of testosterone therapy using a novel fertility treatment regimen. A single-center retrospective cohort analysis. Seventy-seven men with previous testosterone use seeking fertility treatment from January 2020 to March 2024. A treatment regimen of 3000IU human Chorionic Gonadotropin (hCG) and 75IU Follicle Stimulating Hormone (FSH) three times a week was utilized. The primary outcome measured was change in sperm concentration during hCG/FSH therapy. The secondary outcome measured was whether concurrent testosterone therapy during hCG/FSH therapy affected recovery of spermatogenesis. Within the entire cohort (n=77), 74% of men demonstrated improvements in their sperm concentrations. There was not a significant difference in recovery of sperm concentration in men who stayed on testosterone therapy during hCG/FSH reboot (No testosterone therapy [n=50], 74% improved vs. Concurrent testosterone therapy [n=27], 74% improved). We report optimal recovery of spermatogenesis with hCG/FSH therapy in infertile men with a history of testosterone use. Concurrent testosterone therapy does not impede hCG/FSH-mediated spermatogenic recovery.

A regression-based approach to the CO2 airborne fraction

The global fraction of anthropogenically emitted carbon dioxide (CO2) that stays in the atmosphere, the CO2 airborne fraction, has been fluctuating around a constant value over the period 1959 to 2022. The consensus estimate of the airborne fraction is around 44%. In this study, we show that the conventional estimator of the airborne fraction, based on a ratio of changes in atmospheric CO2 concentrations and CO2 emissions, suffers from a number of statistical deficiencies. We propose an alternative regression-based estimator of the airborne fraction that does not suffer from these deficiencies. Our empirical analysis leads to an estimate of the airborne fraction over 1959–2022 of 47.0% (± 1.1%; 1σ), implying a higher, and better constrained, estimate than the current consensus. Using climate model output, we show that a regression-based approach provides sensible estimates of the airborne fraction, also in future scenarios where emissions are at or near zero.

Validation of a Commercial ELISA Kit for Non-Invasive Measurement of Biologically Relevant Changes in Equine Cortisol Concentrations

The measurement of fecal cortisol/corticosterone metabolites (FCMs) is often used to quantify the stress response. The sampling method is relatively non-invasive, reduces concern for elevation of cortisol from the sampling method, and has been shown to measure cortisol more consistently without the daily diurnal rhythm observed in blood. Commercial ELISA (enzyme-linked immunoassay) kits offer benefits over previously validated immunoassay methods but lack validation. The objective of this study was to evaluate a commercial ELISA kit (Arbor AssaysTM DetectX® Cortisol ELISA kit, K003-H1, Ann Arbor, MI, USA) and provide analytical and biologic validation of equine fecal and plasma samples. Horses (4 male, 4 female, mean ± SD: 4 ± 5 yr) were transported for 15 min with limited physical and visual contact via a livestock trailer. Blood and fecal samples were collected pre- and post-transportation. Parallelism, accuracy, and precision tests were used to analytically validate this kit. Data were analyzed using PROC MIXED in SAS 9.4. Plasma cortisol concentrations increased in response to trailering (254.5 ± 26.4 nmol/L, 0 min post-transportation) compared to pre-transportation (142.8 ± 26.4 nmol/L). FCM concentrations increased 24 h post-trailering (10.8 ± 1.7 ng/g) when compared to pre-transportation (7.4 ± 1.7 ng/g). These data support that changes in FCMs can be observed 24 h post-stressor. In conclusion, the Arbor AssaysTM DetectX® Cortisol ELISA kit is a reliable, economic option for the measurement of biologically relevant changes in cortisol in equine plasma and FCMs.

Analgesic effect of dance movement therapy: An fNIRS study

ObjectiveThis study aims to explores the physiological and psychological mechanisms of exercise-induced hypoalgesia (EIH) by combining the behavioral results with neuroimaging data on changes oxy-hemoglobin (HbO) in prefrontal cortex (PFC). MethodsA total of 97 healthy participants were recruited and randomly divided into three groups: a single dance movement therapy (DMT) group, a double DMT group, and control group. Evaluation indicators included the pressure pain threshold (PPT) test, the color-word stroop task (CWST) for wearing functional near-infrared spectroscopy (fNIRS), and the self-assessment manikin (SAM). The testing time is before intervention, after intervention, and one hour of sit rest after intervention. Results1) Repeated measures ANOVA revealed that, there is a time * group effect on the PPT values of the three groups of participants at three time points. After 30 min of acute dance intervention, an increase in the PPT values of 10 test points occurred in the entire body of the participants in the experimental group with a significant difference than the control group. 2) In terms of fNIRS signals, bilateral DLPFC and left VLPFC channels were significantly activated in the experimental group. 3) DMT significantly awakened participants and brought about pleasant emotions, but cognitive improvement was insignificant. 4) Mediation effect analysis found that the change in HbO concentration in DLPFC may be a mediator in predicting the degree of improvement in pressure pain threshold through dance intervention (total effect β = 0.7140). ConclusionIn healthy adults, DMT can produce a diffuse EIH effect on improving pressure pain threshold, emotional experience but only showing an improvement trend in cognitive performance. Dance intervention significantly activates the left ventrolateral and bilateral dorsolateral prefrontal cortex. This study explores the central nervous system mechanism of EIH from a physiological and psychological perspective.

Mathematical Model of Double-Pulse Electrolysis of Alkalines

A mathematical model of a simple two-chamber electrolyzer was formulated and substantiated for the study of possible processes occurring during electrolysis. In the calculations, the following factors were taken into the account: electrochemical reactions, electromigration of ions in the potential gradient field, diffusion through the membrane that separates the cathode and anode chambers, the change in the volume of the solution due to the water molecules compaction in the hydration shells of ions, and the change in the alkali concentration. The electrolysis mode consists of two consecutive current pulses: the first-cathodic and the next – anodic. Theoretical calculations of the system state in the two-pulse mode are the most accurate since the chemical composition of the electrolyte does not change at the moment of switching the current. However, the directions of electrode reactions, electromigration, and electroosmosis change. In the electrolysis mode with more pulses, it would be impossible to calculate the state parameters. A mathematical model was created for a comparative analysis of the influence of different electrolysis conditions on the speed ratio of various processes.

Confirmation of the feasibility of using agrobyproduct biochar in thermal power plants through oxygen pyrolysis and conventional pyrolysis

This study investigates the feasibility of utilizing agrobyproduct biochar as a substitute for fossil fuels in thermal power plants by comparing oxygen-rich and oxygen-lean pyrolysis processes. The biomass types examined include soybean pods (BE), bamboo (BB), and wood pellets (WP). Results demonstrate that oxygen-lean pyrolysis at high temperatures enhances biochar's carbon content and energy density. Mass yields varied, with WP showing the highest yield at 500℃ under oxygen-lean conditions. Elemental analysis indicated increased carbon content and improved fuel properties with higher pyrolysis temperatures. Proximate composition analysis revealed decreased volatile matter and increased fixed carbon and ash content, leading to higher fuel ratios. Calorific values increased significantly across all biomasses, particularly under oxygen-lean conditions. Gas analysis showed significant changes in O2, CO2, and CO concentrations with temperature variations. Combustion indices and physical properties like aromaticity and Hardgrove grindability index improved with higher temperatures. Optimal pyrolysis conditions were identified as 325℃ for WP, 350℃ for BB, and 300℃ for BE, with BE also performing well at 500℃. The study concludes that optimized agrobyproduct biochar can effectively replace conventional fossil fuels, offering high energy yield and enhanced combustion properties.

Impacts of age, type 2 diabetes, and hypertension on circulating neutrophil gelatinase-associated lipocalin and kidney injury molecule-1 after prolonged work in the heat in men.

Prolonged work in the heat increases the risk of acute kidney injury (AKI) in young men. Whether aging and age-associated chronic disease may exacerbate the risk of AKI remains unclear. We evaluated plasma neutrophil gelatinase-associated lipocalin (NGAL) and serum kidney injury molecule-1 (KIM1) before and after 180min of moderate-intensity work (200W/m2) in temperate (wet-bulb globe temperature [WBGT] 16°C) and hot (32°C) environments in healthy young (n = 13, 22years) and older men (n = 12, 59years), and older men with type 2 diabetes (T2D; n = 9, 60years) or hypertension (HTN; n = 9, 60years). There were no changes in NGAL or KIM1 concentrations following prolonged work in temperate conditions in any group. Despite a similar work tolerance, the relative change in NGAL was greater in the older group when compared to the young group following exercise in the hot condition (mean difference + 82ng/mL; p < 0.001). Baseline concentrations of KIM1 were ~ 22pg/mL higher in the older relative to young group, increasing by ~ 10pg/mL in each group after exercise in the heat (both p ≤ 0.03). Despite a reduced work tolerance in the heat in older men with T2D (120 ± 40min) and HTN (108 ± 42min), elevations in NGAL and KIM1 were similar to their healthy counterparts. Age may be associated with greater renal stress following prolonged work in the heat. The similar biomarker responses in T2D and HTN compared to healthy older men, alongside reduced exercise tolerance in the heat, suggest these individuals may exhibit greater vulnerability to heat-induced AKI if work is prolonged.

Mobile monitoring of air pollutant concentration in the park of Urumqi, China

The concentrations of PM2.5, PM10, O3 and NO2 in Urumqi People's Park were monitored by mobile monitoring in July and October 2023, and the temporal and spatial changes of pollutant concentrations in urban parks and their influencing factors were analyzed. The results show that park can effectively reduce PM and NO2 concentration, increase O3 concentration. PM concentration in the park was higher in the morning than the noon. O3 and NO2 concentration is lower in the morning than the noon. The concentration within the park was lower than that outside the park. The mitigative effect of pollutants in the park was better in summer than in autumn. The concentration of PM in the park showed a high value aggregation, and PM2.5 and PM10 showed the same spatial distribution in the high value cluster, and the pollution of both showed homology in summer. O3 and NO2 concentrations tend to accumulate at low value cluster. Pollutants are affected by the local environment. PM2.5 concentration is greatly affected by wind speed and distance from water, O3 concentration is greatly affected by temperature and average distance from road. The closer to the road, the higher the concentration of NO2. Attention should be paid to the landscape design of the buffer zone of 30–50 m with the high pollution area. This study can provide reference for park planning and design.

Evaluation of Blood Lactate among Different Player Roles: A Pilot Study on Competitive Young Male Soccer Players.

Soccer match requires anaerobic and aerobic energetic metabolism. The aim of this pilot study was to investigate the changes in blood lactate concentration in young male soccer players in different playing roles at different time points after the soccer match. Following an initial screening of 134 young soccer athletes, 8 male athletes (average age of 15.5 ± 5 SD) were chosen for their characteristics similar to those of competitive athletes. Players were categorized as goalkeeper, central defender, central midfielder, and forward. Blood lactate concentrations were determined using a portable device at different times (10 min, 5 and 16 h) after the soccer match by a maximum effort test on a treadmill. The data were analyzed by one-way analysis of variance ANOVA, followed by Bonferroni's post-hoc test. The following results (mean ± SD) were obtained: VO2max (%) 60.33 ± 3.10; blood lactate (mM) end match (10 min) 2.17 ± 0.78, post-match-early (after 5 h) 2.2 ± 0.42, postmatch-late (16 h) 3.2 ± 0.84. ANOVA analysis indicated that the blood LA concentrations at end-match (10 min) and post-match-early (5 h) were statistically significative lower than those determined at post-match-late (16 h) (p < 0.05). These results suggest that aerobic mechanisms can also use LA as an energy source, contributing to the reduction of its blood concentration. This effect can be due to reduced maximal work during a soccer match and to the LA removal during exercise at reduced intensity. These data can provide indications for planning suitable training strategies for young male soccer players.

Fentanyl, Heroin, Methamphetamine, and Cocaine Analyte Concentrations in Urine Drug Testing Specimens

The US is experiencing a protracted drug overdose crisis primarily associated with exposure to illicitly manufactured fentanyl (IMF), methamphetamine, and cocaine. Overdose risk and treatment responses may be directly affected by absolute drug exposure concentrations and drug use prevalence. To quantify changes in absolute drug exposure concentrations from 2013 to 2023. This cross-sectional study analyzed urine drug testing (UDT) results from urine specimens collected between January 1, 2013, and August 22, 2023, in 49 states and the District of Columbia. Urine specimens were obtained from patients aged 18 years or older who presented to substance use disorder treatment clinics. The UDT was ordered by clinicians based on medical necessity. Urine specimens were analyzed for the following drugs or metabolites (analytes tested in parentheses): fentanyl (fentanyl), heroin (6-monoacetylmorphine), cocaine (benzoylecgonine), and methamphetamine (methamphetamine) using liquid chromatography with tandem mass spectrometry. Relative concentrations of fentanyl, heroin, cocaine, and methamphetamine. Creatinine-normalized drug concentration values were log-transformed prior to visualization and statistical analyses. The Mann-Kendall trend test was performed to examine trends over time. To estimate the geospatial and temporal patterns of drug concentration, a second series of models (1 for each drug) with an interaction effect for clinic location and collection year were fit. A total of 921 931 unique UDT samples were collected from patients (549 042 males [59.6%]; median [IQR] age, 34 [27-44] years). The adjusted fentanyl concentration in urine specimens was 38.23 (95% CI, 35.93-40.67) ng/mg creatinine in 2023 and 4.61 (95% CI, 3.59-5.91) ng/mg creatinine in 2013. The adjusted methamphetamine concentration was 3461.59 (95% CI, 3271.88-3662.30) ng/mg creatinine in 2023 and 665.27 (95% CI, 608.51-727.32) ng/mg creatinine in 2013. The adjusted cocaine concentration was 1122.23 (95% CI, 1032.41-1219.87) ng/mg creatinine in 2023 and 559.71 (95% CI, 524.69-597.06) ng/mg creatinine in 2013. The adjusted heroin concentration was 58.36 (95% CI, 48.26-70.58) ng/mg creatinine in 2023 and 146.59 (95% CI, 136.06-157.92) ng/mg creatinine in 2013. Drug concentrations varied across US Census divisions. This cross-sectional study found that absolute concentrations of fentanyl, methamphetamine, and cocaine in urine specimens increased from 2013 to 2023, with a decrease in heroin concentration during that period. The findings suggest that exposure to these substances, as well as the illicit drug supply, has fundamentally changed in many parts of the US, highlighting the need to reinforce surveillance initiatives and accelerate efforts to treat individuals with IMF and/or stimulant exposure.

Deterioration of fire resistance of ultra-high-performance polypropylene-fibre-reinforced concrete (UHPPFRC) under long-term acid rain corrosion action

The application of ultra-high-performance polypropylene-fibre-reinforced concrete (UHPPFRC) has become widespread due to its superior mechanical properties and non-flammable characteristic. Compared to UHPC, the fire resistance of UHPPFRC, which is crucial in ensuring structural integrity and safety during fire incident, has been improved by the addition of PP fibres. In recent years, the escalation of industrial emission has resulted in a more pronounced pollution of acid rain, a major type of sulphate attack on outdoor concrete structures, leading to the aging of UHPPFRC. Given the long service life of civil engineering structures, the fire performance of aging UHPPFRC should be given significant consideration, yet few studies have taken it into account. This study, for the first time, analyses the deterioration of fire resistance of acid-rain-induced aging UHPPFRCs and compares their probability of failure under fire condition across different corrosion durations, providing guidance for the maintenance of UHPPFRC in acid-rain-prone areas. A novel coupled chemo-thermal-mechanical model is developed, which is employed to investigate the sulphate penetration process and internal stress development within UHPPFRC during the corrosion stage, and to predict temperature and internal stress distribution during the subsequent heating stage. The effects of sulphate concentration, heating rate and fibre dosage on the probability of failure of aging UHPPFRC are then studied. The results obtained from the numerical investigation indicate that the aging effect can significantly compromise the fire resistance of UHPPFRC and augment the probability of failure at elevated temperature. Also, the probability of failure of aging UHPPFRC is more sensitive to changes in sulphate concentration than changes in heating rate.

Fingerprints of El Niño Southern Oscillation on global and regional oceanic chlorophyll-a timeseries (1997–2022)

With the advancement of present-day ocean color satellites, the spatiotemporal variations of oceanic Chlorophyll-a (Chl-a) concentration, a proxy for phytoplankton population, can be monitored at regional and global scales. Estimating long-term changes in Chl-a concentration, however, is mainly constrained by the limited availability of ocean color data and the significant influence of climate oscillations like the El Niño Southern Oscillation (ENSO). In this study, we investigate the influence of ENSO on regional and global Chl-a timeseries using two ocean color datasets spanning from September 1997 to December 2022. Our analysis found that global Chl-a concentration exhibits a significant increasing trend over the study period. Most of the increasing trends are detected in the Southern Hemisphere (SH) and high-latitudinal regions, including the Southern Ocean. In light-limited regions like the Southern Ocean, enhanced Chl-a concentration shows a strong positive correlation with warming sea surface temperature (SST). Conversely, most oceans in the Northern Hemisphere (NH) exhibit decreasing trends, which are highly correlated with warming SST and ENSO phases. Additionally, we identify distinctive fingerprints of four extreme ENSO events: two extreme El Niño events (1997–1998 and 2015–2016) and two triple La Niña events (1998–2001 and 2020–2022) in these timeseries. Furthermore, empirical orthogonal function (EOF) analysis reveals that the dominant mode of interannual Chl-a variability is associated with an ENSO-like pattern, accounting for about 13 % of the total variability. Intriguingly, this principal mode is highly correlated with the phases of ENSO (R = -0.87) and Pacific Decadal Oscillation (PDO) (R = −0.90) on an interannual scale. This study provides insights into assessing the impacts of ENSO on long-term Chl-a trend estimation.

Enhanced performance of cyclone separator through coupling of centrifugal force, electrostatic force and particle pre-charge

The electrostatic enhancement can effectively improve the performance of cyclone separator at low load or high-temperature, but its application is limited owing to the reduction of spark voltage in high-temperature. Aiming at this question, a new technology coupling centrifugal force, electrostatic force and particle pre-charge was proposed. The characteristics of particles charging and agglomeration were analyzed, and the influence of different factors on the change of particle partition number concentration and total removal efficiency of cyclone separator were studied. The results showed that, increasing the charge generator voltage and decreasing the main pipe gas velocity can increase the particles charge quantity and improve agglomeration, which is benefit for the efficiency improvement of either cyclone separator or electrostatic cyclone separator, especially at low inlet gas velocity. Higher charge generator voltage and lower inlet gas velocity, more obvious efficiency improvement. The total removal efficiency can be increased by up to 10 % and 9 % respectively for the cyclone separator and electrostatic cyclone separator because of particle pre-charge at 10 m/s of inlet gas velocity, and the removal efficiency of fine particles can also be effectively improved. Comparing with the electrostatic cyclone separator, achieving the same total removal efficiency, the internal voltage can be reduced 16 kV through particle pre-charge. The electrostatic force and centrifugal force were the main factor of the small particles and big particles removal, respectively.

Estimation of Blood Calcium and Potassium Values from ECG Records

Abstract The identification of diseases caused by changes in ion concentration is quite difficult and yet plays a decisive role in the success of clinical care, diagnosis and treatment. The clinically proven approach to diagnosing electrolyte concentration imbalance is blood tests. There is a need to provide a non-invasive diagnostic method that is not of a temporary nature. Bio-signals such as the electrocardiogram (ECG) can be used to meet this demand and become diagnostic tools that facilitate home monitoring of electrolyte concentration on a permanent basis. This study investigates the feasibility and efficiency of methods based on machine learning (ML) and ECG recordings in monitoring critical levels of existing potassium and calcium concentration. Morphological, frequency and frequency-time domain features were extracted to automatically estimate calcium and potassium levels. Furthermore, the potential of estimates based on modeling approaches will be demonstrated to gain insights into relevant clinical findings and improve the performance of monitoring approaches. Using the hold-out validation method, the best results in terms of mean square error (MSE) and R for estimating the calcium value are 0.7157 and 0.57347, using fuzzy inference systems (FIS). Here, R represents the proportion of the variance in the calcium value that is explained by the model.

A dynamical calo-porosimeter to characterize wetting and drying processes in lyophobic nanometric pores.

Lyophobic heterogeneous systems, based on porous fluids made of ordered nanoporous particles immersed in a non-wetting liquid, constitute systems of interest for exploring wetting, drying, and coupled transport phenomena in nanometric confinement. To date, most experimental studies on the forced filling and spontaneous emptying of lyophobic nanometric pores, at pressures of several tens of MPa, have been conducted in a quasi-static regime. However, some studies have shown that dynamical measurements are essential to shed light on the rich physics of these phenomena. We describe here a dynamical calo-porosimeter that allows for the simultaneous mechanical and calorimetric characterization of filling and emptying cycles over four decades of timescales, ranging from a few milliseconds to 10 seconds. This thermally regulated instrument can be operated between -5 and 70°C. It also enables the study of a given porous material successively with different liquids by switching from one to another. The characterization of wetting dynamics, the study of slow kinetics due to changes in solute concentration, and the rapid measurement of the heat of wetting, among other thermal properties, are presented as examples of the possible applications of this apparatus.

Effects of supplementing rumen-protected arginine on performance of transition cows

An experiment was conducted to determine the effects of supplementing rumen-protected arginine (RPA) on productive performance in dairy cows. One-hundred and 2 cows were blocked by parity and then by energy-corrected milk (ECM) yield. Within block, cows were randomly assigned to control (CON) that received 200 g/d of a mixture of hydrogenated soybean oil and heat-treated soybean meal to supply 30 g of metabolizable protein (MP), or 200 g/d of a product containing 30 g of metabolizable arginine (RPA), which increased the dietary arginine from 5.7 to 7.5% of the MP from 250 d of gestation to 21 d postpartum. After 21 d postpartum, cows were fed the same diet and data were collected until 84 d postpartum. Cows fed RPA produced an additional 2.5 kg of colostrum (5.3 vs. 7.8 ± 1.0 kg) and 220 g more immunoglobulin G (526 vs. 746 ± 93 g) than CON cows. Supplementing RPA increased the yields of milk (32.8 vs. 34.9 ± 1.0 kg/d), ECM (37.8 vs. 40.9 ± 1.2 kg/d), and milk total solids (4.48 vs. 4.86 ± 0.14 kg/d) in the first 21 DIM. The benefits of RPA extended beyond the period of supplementation, with a 6.4% increase in yield of ECM per kg of dry matter consumed in all cows (1.88 vs. 2.00 ± 0.05 kg/kg) and an increase in ECM yield, but only in parous cows (44.2 vs. 48.5 ± 1.5 kg/d). Feeding RPA increased the concentrations of urea N in plasma pre- (12.5 vs. 13.9 ± 0.4 mg/dL) and postpartum (11.6 vs. 13.2 ± 0.4 mg/dL), and in milk during the first 21 d postpartum (11.0 vs. 12.0 ± 0.3 mg/dL). Treatment did not affect the concentrations of AA in plasma prepartum, but feeding RPA tended to increase citrulline (72.5 vs. 77.5 ± 2.7 μM), whereas RPA either tended to decrease isoleucine (129.5 vs. 120.9 ± 5.7 μM) or decreased the concentrations of leucine (181.3 vs. 170.2 ± 6.4 μM) and valine (293.2 vs. 276.7 ± 10.4 μM) postpartum. Feeding RPA increased the relative expression of transcripts involved in AA transport (SLC38A4), urea cycle (ARG1), and gluconeogenesis (PC, PEPCK, and G6PC) in hepatic tissue. Feeding diets to supply additional arginine as RPA during the transition period benefited productive performance in dairy cows that extended beyond the period of supplementation despite minor changes in plasma AA concentrations.

Correlations between the increase in atmospheric CO2 and temperature, and the subsequent increase in silica, and groundwater organisms

Rising atmospheric temperature and CO2 impact all freshwater systems. In groundwater, one such impact is CO2- and temperature-induced weathering, which leads to more intense weathering of silicate rocks. Here, we tested whether the increased CO2 levels, the weathering, or rather the increasing temperature, impacted on fauna and prokaryotes in the groundwater ecosystem. We also conducted the analyses separately for two groups of wells, one of which contained wells that were secluded from the surface (and often rather deep), and wells tapping the quaternary aquifers (often rather shallow) which exchange with the surface more intensely. Organism abundances and relative composition did not correlate with temperature or CO2 levels. While many organisms rely on silica, in contrast, we found negative correlations between silica concentrations and fauna. The increases in silica concentrations over time, i.e. temporal trends, also partly correlated negatively with organisms. We hypothesize that the unexpected negative correlations are not direct effects, but indirectly indicate that groundwater communities do not adapt rapidly enough to changes in silica concentrations, but also more generally to changes for which silica might only be a proxy. Groundwater fauna take part in the ecosystem service of water self-cleaning and are thus considered beneficial for sustainable raw water for drinking water production. The propensity of groundwater fauna to decrease with increases in silica, jeopardizes future drinking water production.

Quantification measurement of hemoglobin with large dynamic range and low detection limit via an optical fiber optofluidic laser with enzyme-catalyzed reaction

Quantitative measurement of hemoglobin (Hb) levels is an essential part of routine medical examinations, disease diagnosis and health status monitoring. In this study, we introduced optical fiber optofluidic laser (FOFL) technology combined with catalytic oxidation reaction to design a laser sensor for sensitive Hb detection. For the H2O2-rhodamine B (RhB) oxidation system, radially emitting FOFL was achieved with a thin-walled hollow optical fiber (HOF) as an optical microcavity and amplified the concentration change of RhB during oxidation by H2O2. Hb was employed as peroxide-mimicking enzyme to catalyze the oxidation system, which sped up the reaction, resulting in an earlier laser extinction time. With the laser extinction time as sensing signal, the Hb sensor achieved a dynamic range of five orders of magnitude and a limit of detection (LOD) of 46.0 pM at an assay time of 40 min. The developed method provides ideas for the exploitation of FOFL biosensing based on catalytic oxidation reactions.