Ultra-purified Water Research Articles

Structural characterization and immunomodulating assessment of ultra-purified water extracted fucoidans from Saccharina latissima, Alaria esculenta and Laminaria hyperborea

Fucoidans, a group of high molecular weight polysaccharides derived mainly from brown algae, are characterized by their high fucose content, degree of sulfation (DS), and intra- and interspecific structural variation. Fucoidans are increasingly recognized due to various reported bioactivities, potentially beneficial for human health. To unlock their potential use within biomedical applications, a better understanding of their structure-functional relationship is needed. To achieve this, systematic bioactivity studies based on well-defined, pure fucoidans, and the establishment of standardized, satisfactory purification protocols are required. We performed a comprehensive compositional and structural characterization of crude and ultra-purified fucoidans from three kelps: Saccharina latissima (SL), Alaria esculenta (AE) and Laminaria hyperborea (LH). Further, the complement-inhibiting activity of the purified fucoidans was assessed in a human whole blood model. The purification process led to fucoidans with higher DS and fucose and lower concentrations of other monosaccharides. Fucoidans from SL and LH resembles homofucans, while AE is a heterofucan rich in galactose with comparably lower DS. Fucoidans from SL and LH showed complement-inhibiting activity in blood and blood plasma, while no inhibition was observed for AE under the same conditions. The results emphasize the importance of high DS and possibly fucose content for fucoidans' bioactive properties.

#1705 Central delivery of acid concentrate for haemodialysis: a single-center experience

Abstract Background and Aims Dialysate is produced by mixing ultra-purified water with acid and bicarbonate concentrates. Acidic concentrate for hemodialysis can be supplied to the dialysis machine through single-use bags or central concentrate supply. Central delivery of acid concentrate represents an innovation in hemodialysis settings in terms of practicality and eco-sustainability as this system is able to produce and distribute ready-to-use acid dialysis concentrate without the use of acid concentrate bags. The aim of our study was to compare the amount of material (including packaging) used to supply acid concentrate using a single-use bag (3.8 L or 4.5 L) or central acid supply at the Nephrology Dialysis and Renal Transplant Unit of Azienda Ospedaliero Universitaria di Modena, Modena, Italy. In particular, we reviewed the amount of consumable material before (January-December 2019) and after the implementation of central concentrate supply (July 2022-June 2023). Lastly, a survey was delivered to all dialysis nurses who work in our dialysis Center to evaluate their feedback on central concentrate supply. Method Our center is equipped with 46 dialysis stations for patients on chronic hemodialysis that in 2019 delivered 30 000 hemodialysis treatments distributed across morning, afternoon, and evening shifts. Granumix system® (Fresenius Medical Care, Bad Homburg, Germany) was installed in 2022. It produces and distributes acid concentrate fluid with two different concentrations of K+ (2 and 3 mEq/L) and a unique concentration of Ca2+ 1.5 mmol/L (see Figure). Results The data collected in 2019 at our Dialysis Center showed that 30 000 acid bags corresponding to 121 000 L of acid concentrate fluid were used to perform hemodialysis. Utilization of bags generated 3 750 kg of pallets, 4 500 kg of plastic and 5 367 kg of boxes. Considering that approximately 10% of the acid concentrate fluid remains unused during each dialysis treatment, approximately 12 000 L of unutilized acid concentrate fluid was wasted. Following the introduction of the Granumix® system, there was a significant reduction (−80.6%) in the utilization of single-use acid concentrate bags (n = 5 805) and, consequently, in the use of boxes (n = 2 294 vs. n = 11 667) and pallets (n = 40 vs. n = 208). The centralized distribution system of acid concentrate led to a significant reduction in waste including boxed, plastic and pallets (2 642 kg vs. 13 617 kg), disposal of residual acidic solution (2 351 liters vs. 12 100 liters), and handling of materials by dialysis staff (37 522 kg vs. 158 117 kg). Another advantage of this system is the optimized usage of acid concentrate fluid. This system ensures that only the required amount of acid for a specific treatment is used, effectively minimizing waste and decreasing the production of special waste. The results of the survey (response rate 75%) documented that 79.5% of the nurses received adequate training for its use; 94.9% experienced a reduction in fatigue and 84.6% declared that had more time to dedicate to patients. Lastly, the survey showed that 96.4% of the participants were completely satisfied with the implementation of this new system. Conclusion Central delivery of acid concentrate is an innovative solution with eco-sustainable potentialities in reducing the consumable materials and workload in hemodialysis. Overall, most nurses expressed satisfaction as this system reduces dialysis staff workload and allows more time for patient care.

Determining the phosphorus release curve for Sunphase HT phytase in nursery pig diets.

A total of 280 pigs (DNA 241 × 600, initially 10.4 ± 0.24kg) were used in a 21-d study to determine the available P (aP) release curve for Sunphase HT phytase (Wuhan Sunhy Biology Co., Ltd., Wuhan, P.R. China) when fed diets with a high phytate concentration. On day 21 post-weaning, considered day 0 of the study, pigs were blocked by average pen body weight (BW) and randomly allotted to 1 of 7 dietary treatments with 5 pigs per pen and 8 pens per treatment. Dietary treatments were derived from a single basal diet, and ingredients including phytase, monocalcium P, limestone, and sand were added to create the treatment diets. Treatments included three diets with increasing (0.11%, 0.19%, and 0.27%) aP from monocalcium P, or four diets with increasing phytase (250, 500, 1,000, or 2,000 phytase unit (FTU)/kg) added to the diet formulated to 0.11% aP. All diets were corn-soybean meal-canola meal-based and were formulated to contain 1.24% SID Lys, a 1.10:1 total calcium-to-phosphorus ratio, and a calculated 0.32% phytate P. Prior to the beginning of the study, all pigs were fed a diet containing 0.11% aP from days 18 to 21 post-weaning. At the conclusion of the study, 1 pig, closest to the mean weight of each pen, was euthanized, and the right fibula, 10th rib, and metacarpal were collected to determine bone ash and density. After cleaning, bones were submerged in ultra-purified water under a vacuum for 4h and then weighed to calculate the density (Archimedes principle). For bone ash, bones were processed using the non-defatted method. From days 0 to 21, increasing aP from monocalcium P increased (linear, P ≤ 0.014) average daily gain (ADG), gain-to-feed (G:F), and final BW. Pigs fed increasing phytase had increased (linear, P ≤ 0.045) ADG, final BW, and plasma inositol concentration as well as improved (quadratic, P = 0.023) G:F. For bone characteristics, pigs fed increasing aP from inorganic P had a linear improvement (P ≤ 0.019) in fibula bone ash weight and percentage bone ash, rib bone ash weight and bone density, and all metacarpal bone properties, with a quadratic response (P ≤ 0.030) for fibula bone density and rib percentage ash. Additionally, pigs fed increasing phytase had increased (P < 0.05) bone ash weight, percentage bone ash, and bone density in either a linear or quadratic fashion depending on the bone analyzed. The available P release curve generated for Sunphase HT phytase for percentage bone ash combining values from the right fibula, 10th rib, and metacarpal is aP release, % = (0.360 × FTU) ÷ (2,330.250 + FTU).

64 Determining the Phosphorus Release Curve for Sunphase HT Phytase from 250 to 2,000 FTU/kg in Nursery Pig Diets

Abstract A total of 280 pigs (DNA 241 × 600, initially 10.4 ± 0.24 kg BW) were used in a 21-day growth study to determine the available P (aP) release curve for Sunphase HT phytase (Wuhan Sunhy Biology Co., Ltd., Wuhan, P.R., China). At approximately 19 d of age, pigs were weaned, randomly allotted to pens, and fed common starter diets. On d 21 post-weaning, considered d 0 of the study, pigs were blocked by average pen body weight (BW) and randomly allotted to 1 of 7 dietary treatments with 5 pigs per pen and 8 pens per treatment. Dietary treatments were derived from a single basal diet and ingredients including phytase, monocalcium P, limestone, and sand were added to create the treatment diets. Treatments included 3 diets containing increasing (0.11, 0.19, and 0.27% aP) inorganic P from monocalcium P, or 4 diets with increasing phytase (250, 500, 1,000, or 2,000 FTU/kg) added to the diet formulated to 0.11% aP. All diets were corn-soybean meal-canola meal-based and were formulated to contain 1.24% SID Lys and an analyzed Ca:P ratio of 1.10:1. Before the beginning of the study, all pigs were fed a diet containing 0.11% aP for a 3-d period (d 18 to 21 post-weaning). At the conclusion of the study, 1 pig, closest to the mean weight of each pen, was euthanized and the right fibula, rib, and metacarpal were collected to determine bone ash and density. After cleaning, bones were submerged in ultra-purified water under vacuum for 4 h. Weights were then collected, and bone density was calculated. For bone ash, bones were placed in a drying oven at 105oC for 7 d and then ashed in a muffle furnace at 600oC for 24 h (Table 1). For the overall experimental period, feeding increasing levels of aP from inorganic P improved (linear, P ≤ 0.014) ADG, G:F, and final BW. Similarly, feeding increasing phytase increased (linear, P ≤ 0.011) ADG and final BW as well as improved (quadratic, P = 0.023) G:F. For fibula bone ash weight and percentage bone ash, rib bone ash weight and bone density, and all metacarpal bone properties, pigs fed increasing levels of aP from inorganic P exhibited a linear improvement (P ≤ 0.019), with a quadratic response (P ≤ 0.030) for fibula bone density and rib percentage ash. Additionally, pigs fed increasing phytase had increased (P &amp;lt; 0.05) bone ash weight, percentage bone ash, and bone density in either a linear or quadratic fashion depending on the bone analyzed. The available P release curve generated for Sunphase HT phytase for percentage bone ash combining values from right fibula, rib, and metacarpal is: aP = (0.360 × FTU) ÷ (2,330.250 + FTU).

Evaluation of hydrogen peroxide permeability, color change, and physical-chemical properties on the in-office dental bleaching with different mixing tip.

This study aims to assess hydrogen peroxide (HP) penetration into the pulp chamber, color change (CC), physical-chemical properties, and material wastage (MW) and material used (MU) in mixing tips when using in-office bleaching gels with two different mixing tips. Forty teeth were divided into five groups (n = 8) based on the bleaching gels used (Pola Office +37.5% [PO+] and Whiteness HP Automixx Plus 35% [AM+]) and the mixing tip types (T-Mixer and Helical). A negative control group was treated with ultra-purified water. HP concentration was measured using UV-Vis, and CC was evaluated with a digital spectrophotometer. Initial concentration, pH, and viscosity were measured through Titration, a Digital pH meter, and Rheometer, respectively. MW and MU were measured using a precise analytical balance. Statistical analysis included two-way ANOVA, Tukey's, and Dunnett's test (α = 0.05). A higher HP concentration was observed with PO+ with the Helical mixing tip in comparison with AM+ (p = 0.01). No significant differences in CC or MU were found for different mixing tips (p = 0.001). The T-mixer mixing tip resulted in significantly less MW (p < 0.00001) and improved mixture homogeneity and viscosity. Utilizing a T-mixer with self-mixing bleaching gels achieves comparable CC while reducing MW. Moreover, it decreases HP penetration when using PO+. For the application of a self-mixing in-office bleaching gel, a T-mixer mixing tip should be recommended, as it reduces the penetration of hydrogen peroxide into the pulp chamber when using PO+, while also minimizing gel wastage.

Microplastics separation using stainless steel mini-hydrocyclones fabricated with additive manufacturing

Microplastics have been widely detected in natural and engineered water systems and removing microplastics from various water matrices has become a major challenge. Mini-hydrocyclones (MHCs) have been previously applied to separate mediums of different phases. Given MHCs' capability of separating fine particles from liquid phase, three MHCs were designed and fabricated in stainless steel with 3D printing. Microplastics of densities that were both lower (<1 g·cm−3) and higher (>1 g·cm−3) than water's density were used to test the separation efficiency in ultra-purified water. The separation test was performed on single-stage MHC as well as MHCs in series in a closed hydraulic circuit. A range of important operational parameters, including split ratio, feed pressure, feed flow rate, and solid concentration, were evaluated to optimize the separation efficiency. The single-stage MHC experiment revealed that >80 % microplastics >20 μm can be effectively removed at the concentration tested, and the separation efficiency peaked at the split ratio of 35 %. MHCs in series demonstrated their ability to further enhance the separation efficiency of the ones with the same density, as well as separate microplastics of different densities. Mini-hydrocyclones' were also used to separate microplastics in synthetic stormwater, and separation efficiency reached 84 % and 98.1 % for low-density polyethylene (LDPE) and polyamide (PA). The results indicated the MHCs' potential for large-scale application in microplastic separation for industrial and municipal wastewater.

Effect of cetyltrimethylammonium chloride on various Escherichia coli strains and their inactivation kinetics by ozone and monochloramine

Cethyltrimethylammonium chloride (CTMA) is one of the most used quaternary ammonium compounds (QACs) in consumer products. CTMA and other QACs are only partially eliminated in municipal wastewater treatment and they can interact with bacteria in biological processes. Currently, there is only limited information on the antimicrobial efficiency of CTMA in matrices other than standard growth media and if and how CTMA influences conventional chemical disinfection. The results obtained in this study showed that the susceptibility of E. coli to CTMA was significantly enhanced in phosphate-buffered saline, lake water and wastewater compared to broth. In broth, a minimum inhibitory concentration (MIC) of CTMA of 20 mgL−1 was observed for E. coli, whereas a 4-log inactivation occurred for CTMA concentrations of about 4 mgL−1 in buffered ultra-purified water, a lake water and wastewater effluent. The impacts of the pre-exposure and the presence of CTMA on inactivation by ozone and monochloramine were tested with three different E. coli strains: AG100 with the efflux pump acrAB intact, AG100A with it deleted and AG100tet with it overexpressed. Pre-exposure of E. coli AG100 to CTMA led to an increased susceptibility for ozone with second-order inactivation rate constants (∼ 106 M−1s−1) increasing by a factor of about 1.5. An opposite trend was observed for monochloramine with second-order inactivation rate constants (∼ 103 M−1s−1) decreasing by a factor of about 2. For E. coli AG100tet, the second-order inactivation rate constant decreased by a factor of almost 2 and increased by a factor of about 1.5 for ozone and monochloramine, respectively, relative to the strain AG100. The simultaneous presence of CTMA and ozone enhanced the second-order inactivation rate constants for CTMA concentrations of 2.5 mgL−1 by a factor of about 3. For monochloramine also an enhancement of the inactivation was observed, which was at least additive but might also be synergistic. Enhancement by factors from about 2 to 4.5 were observed for CTMA concentrations > 2.5 mgL−1.

Clinical Images: β2 -Microglobulin amyloidosis.

The patient, a 55-year-old man on hemodialysis (HD) (in-center HD three times per week) for 32 years (low-flux HD for 25 years), presented with a 10-year history of progressive deformity of the hands. The patient was diagnosed with β2-microglobulin amyloidosis, or dialysis-related amyloidosis (DRA), on the basis of clinical presentation and radiographic findings. Although histological assessment remains the gold standard for DRA, the diagnosis is usually clinical in patients suspected of needing HD and relies on the combination of typical clinical features, such as carpal tunnel syndrome, camptodactyly, and characteristic radiographic findings of multiple rapidly enlarging bone cysts. The bone cysts are radiolucent lesions and frequently have thin sclerotic margins (white arrows). Amyloid deposition along the flexor tendons of the hand leads to irreducible flexion contractures of the fingers (white arrowheads). Besides DRA findings, vascular calcifications, such as arteriosclerosis (red arrows), and a calcified arteriovenous fistula anastomotic aneurysm (red arrowheads) were also present in our patient's radiography. In the past, DRA was nearly a universal finding in patients with an HD vintage of more than 10 years. Also, DRA has been described in patients undergoing peritoneal dialysis and even in patients with chronic kidney disease before the initiation of dialytic therapy. However, the epidemiology of DRA has decreased in the past 20 years because of the use of high-flux membranes that have superior β2-microglobulin clearance, ultrapurified water, and more biocompatible membranes that generate less inflammation (1). Apart from enhancing β2-microglobulin clearance by high-flux HD membranes or kidney transplantation, treatment of DRA is otherwise palliative. The most debilitating aspects of DRA are carpal tunnel syndrome and paraparesis due to epidural β2-microglobulin amyloid deposition. Moreover, DRA has been shown to predispose to pathologic fractures due to bone cysts in rare cases (2). Analgesics may help with periarticular and bone pain (3).

MO666INVESTIGATIONS INTO DIFFERENCES AND SIMILARITIES BETWEEN SHORT DAILY HIGH-FLUX HEMODIALYSIS AND SHORT DAILY ON-LINE HEMODIAFILTRATION

Abstract Background and Aims Short daily hemodialysis (SDHD) has improved outcomes observed in conventional thrice-weekly hemodialysis (CHD). Analogously, short daily hemodiafiltration (SDHDF) has also improved outcomes observed in conventional thrice-weekly hemodiafiltration (CHDF). Furthermore, while high-volume CHDF has been proclaimed to be superior to CHD, there have been no studies comparing SDHDF to SDHD. We performed a comparison of clinical, laboratory, echocardiographic and quality of life features in dialysis patients treated by SDHD or SDHDF. Method Twelve patients (mean age 60.8±15.4 years; 7 males; AVF 7, AVG 1, Catheter 4) on regular in-center SDHD program were studied in a longitudinal, prospective, non-randomized, single-subject A-B-A design comparing high-flux SDHD to post-dilution on-line SDHDF. Patients had been for at least 6 months on SDHD (105-150min, 6x/week; SDHD1) and were clinically stable before conversion to SDHDF (105-150min, 6x/week, mean total convective volume of 63.57±5.44 L per week) for 6 months. Following that, all patients were switched back to SDHD for another 6 months (SDHD2). Data were collected at the end of each period. Dialysis parameters throughout the study were matched and set as follows: high-flux polysulfone dialyzers (BBraun Xevonta Hi 23®), blood flow 300–350 mL/min, dialysate flow 500 mL/min and ultra-purified water (Aquaboss heat disinfection osmosis). The results were expressed as mean ± standard deviation. Each patient served as his/her own control. Repeated measures analysis of variance (ANOVA) were used. Results Slightly higher predialysis mean arterial pressure (MAP) levels were observed during SDHDF (102.51±11.28 mmHg) compared to SDHD1 (MAP 95.5±9.82 mmHg, p&amp;lt;0.01) or to SDHD2 (97.61±11.19 mmHg, p=0.03), without significant differences in intradialytic blood pressure variability. Similarly, there was an increase in predialysis hemoglobin levels (Hb) during SDHDF (Hb 12.39±1.2 g/dL), compared to SDHD1 (Hb 11.30±1.09 g/dL, p=0.02) or to SDHD2 (Hb 11.23±1.84 g/dL, p&amp;lt;0.01), although there were no significant differences in erythropoietin-stimulating agent or iron supplementation weekly doses, transferrin saturation rates or ferritin levels. Solute kinetics measurements showed higher myoglobin clearance during SDHDF (45.95±11.0 mL/min) compared to SDHD1 (20.11±5.2 mL/min, p&amp;lt;0.01) or to SDHD2 (21.39±3.55 mL/min, p&amp;lt;0.01). Likewise, there was a slight increase in β2-microglobulin removal in SDHDF (64.92±10.4 mL/min) compared to SDHD1 (59.78±17.0 mL/min, p&amp;lt;0.01) or to SDHD1 (53.01±7.71 mL/min, p&amp;lt;0.01), whereas there were no significant differences in urea and creatinine clearances. On the other hand, predialysis osteometabolic (serum PTH, calcium, phosphate, alkaline phosphatase, sodium, potassium, glucose and glycated hemoglobin), inflammatory (serum c-reactive protein and interleukin-6) or nutritional (serum albumin, total protein and lipid profile) parameters did not change significantly during the study. Left ventricular mass index, left atrial volume index and global longitudinal strain, assessed by echocardiography at the end of all 3 periods, were similar, as well as brain natriuretic peptide and homocysteine serum levels. Additionally, there were no significant changes in any quality of life features evaluated by Kidney Disease Quality of Life-Short Form, or symptoms assessed by Edmonton Symptom Assessment System Revised Renal, throughout the full course of the study. Conclusion In spite of mild increase of predialysis mean arterial pressure and hemoglobin levels along with greater removal of middle molecular weight solutes, no others clinical, laboratory, echocardiographic or quality of life findings differed significantly during the three periods. Together, these data do not provide evidence of clinically meaningful benefit from on-line hemodiafiltration over high-flux hemodialysis, both performed six times a week.

Development and Validation of a Fast and Selective HPLC Method for the Determination of Amphotericin B in Nose-to-Brain Nanoliposome

A simple, fast, and selective HPLC method is presented to quantified amphotericin B (AmB) in a nose-to-brain nanoliposomal pharmaceutical formulation. The development was based on the design of experiments (DoE) approach. The chromatographic analysis was validated on a C18 Zorbax reversed-phase column (250 mm x 4,6 mm I.D.) with 5 µm of particle size using mobile phase, consisting of a binary mixture of ultra-purified water and an organic composition of acetonitrile, methanol, and tetrahydrofuran (75:17:8, v/v). The isocratic flow rate was 1.0 mL.min-1, and the detection at 383 nm. The 12 minutes running time being selective between the main peak from possible degradation products, linear and accurate for the concentration range of 0.5 to 7.0 μg.mL-1, and precise demonstrating a relative standard deviation of 0.01 % (n = 6). Application of this method to assay and stability studies of AmB in nanoliposomal lipid-based is provided.

A novel carbamide peroxide polymeric nanoparticle bleaching gel: Color change and hydrogen peroxide penetration inside the pulp cavity.

This study evaluated the hydrogen peroxide (HP) penetration inside the pulp cavity and the color change of teeth submitted to the 15% carbamide peroxide (CP) nanoparticle bleaching gel at several application times. Premolars were divided into nine groups (n = 6) according to 15% CP bleaching agents (nanoparticle and commercial) and to application times (15, 30, 45, and 60 minutes). A negative control was exposed to ultra-purified water. After a whitening procedure, the HP concentration (μg/mL) inside the pulp cavity was assessed via spectrophotometry. The color change (ΔE* and ΔE00*) was evaluated with a spectrophotometer. Data were analyzed via two-way ANOVA and Tukey (α = 0.05). A lower concentration of HP was detected for CP nanoparticle gel after 30 and 45 minutes of whitening procedure (P = .001). The bleaching groups promoted a higher color change (ΔE* and ΔE00*) regardless of the application time (P = .0001). The CP nanoparticle gel reduced HP inside the pulp cavity, and showed effective bleaching compared with CP commercial gel. Using 15% carbamide peroxide nanoparticle bleaching gel decreased the HP penetration inside the pulp cavity and may decrease bleaching-induced tooth sensitivity in at-home bleaching.

Particle-induced nanobubble generation for material-selective nanoparticle flotation

The presented work investigates particle-induced nanobubble generation in order to extend the applicability of material-selective pressure flotation towards nanoscale materials. During a gas treatment procedure, filtered compressed air in the range of 0 bar–2 bar overpressure was introduced into colloidal suspensions in ultra-purified water until saturation was obtained. Nanobubble formation in the suspension occurred after slow depressurization with a gas vent. Suspensions of platinum nanoparticles and polystyrene beads were used to examine the effects of particle hydrophobicity and roughness. Using nanoparticle-tracking-analysis (NTA), the evaluation of particle size and scattered light intensity showed the occurrence of nanobubbles, both, as a separate phase (bulk nanobubbles) and attached to the particles’ surface. The sharply separated nanobubble peak was observed in number density NTA plots of gas treated platinum nanoparticles. The size of the hydrophilic platinum particles remained unchanged. In contrast, for hydrophobic polystyrene particles, the hydrodynamic diameter increased during a gas treatment procedure. The experimental results are understood, on the one hand, as the nucleation of bulk nanobubbles in the cavities of hydrophilic platinum particles and, on the other, as surface-growth of nanobubbles attached to the hydrophobic polymer particles.

Urinary excretion profile of prednisone and prednisolone after different administration routes.

The urinary excretion profile of prednisolone and prednisone after both systemic (i.e., oral) and topical (i.e., ocular and intranasal) administration was studied by liquid chromatography coupled to mass spectrometry, also to select the most appropriate marker(s) of intake for doping control purposes. Urines were collected from ten subjects every 3 h before and after the administration of therapeutic doses of pharmaceutical formulations containing either prednisone or prednisolone. Samples were subjected to enzymatic hydrolysis (performed for the investigation on the glucuronide profile) followed by liquid/liquid extraction with tert-butylmethylether in alkaline conditions. The chromatographic separation was carried out on C18 column, employing as mobile phases ultrapurified water and acetonitrile, both containing 0.1% of formic acid. Detection was achieved using as mass spectrometric analyzer a triple quadrupole, with positive ion electrospray ionization and multiple reaction monitoring as acquisition mode. After both systemic and topical use, the compounds excreted in urine in higher concentration were prednisone, prednisolone and 20β-dihydro-prednisolone followed by 20α-dihydro-prednisolone and 20α/β-dihydro-prednisone. All were excreted mainly as unconjugated compounds, with a maximum of excretion in the first 3-9 h after the administration. After systemic use, prednisone and prednisolone were both detectable for at least 24 h in concentrations ranging from 5 to 500 ng/mL and from 5 to 900 ng/mL respectively. Whereas, after topical administration, prednisone and prednisolone were detectable for at least 18 h in concentrations ranging from 5 to 140 ng/mL and from 5 to 50 ng/mL respectively.

Hydrogen production in liquid water by femtosecond laser-induced plasma

Development of alternative methods for hydrogen production from liquid water requires novel research approaches. In the present study, we investigated the yet unexplored method of water splitting by femtosecond laser pulses (100 fs, λ = 800 nm) focused into a quartz cell containing ultra-purified water. As a result of plasma-induced radical reactions, the formation of stable products including molecular H2 and H2O2 was identified and quantified as a function of irradiation time, repetition rate and pulse energies up to 1 mJ. The observed dependencies provided new insight into the basic chemical processes taking place in the plasma generated in water by focused laser pulses. It was found that the energy efficiency of hydrogen production increased with the decrease of pulse energy and repetition rate. Under appropriate irradiation conditions, an advantageous stoichiometry of water decomposition only into pure H2 and H2O2 (without O2) was achieved. An original way of process intensification (a series of separate laser beams of adequately low energy generating plasma at different places, a sufficiently fast water flow through the irradiation zones) was proposed in order to improve the energy yield of hydrogen generation and to ensure the evolution of pure hydrogen as the only gaseous product of the water splitting. Taking into account the suggested solution, the predicted energy efficiency of hydrogen production of 0.4 g H2/kWh was found to be comparable to other plasma methods for H2 generation. Our results show that direct production of pure H2 using femtosecond laser pulses is a fully reasonable process that carries considerable potential for both research and application.

Characterization of CMP Slurries Using Densitometry and Refractive Index Measurements.

We investigated the possibility of employing refractive index (RI) measurements for inline incoming slurry control at the point of use (POU), as an alternative to the widespread densitometry method. As such, it became necessary to determine if RI could detect smaller changes in slurry composition and, therefore, provide a tighter control. Three industrially-relevant silica-based slurries, namely, Fujimi PL-7106, Klebosol 1501-50, and CMC W7801, were characterized using both densitometry and RI measurements. Initial solutions of the three slurries were prepared and increasingly small amounts of ultrapurified water (UPW) were added to study the change in slurry properties. Results showed that both density and RI decreased linearly with the addition of water for all three slurries, with the 1501-50 being the most sensitive to water addition. A linear correlation between the two properties was found, with R2 values that exceeded 0.95 in all cases. Furthermore, the approximate limit of detection of both metrology tools was estimated based on the slope of the fitting line and resolution. When compared to densitometry, RI was found to be the far superior method for detecting smaller changes in water concentration.

Fate of Cr(III) during Ozonation of Secondary Municipal Wastewater Effluent

ABSTRACTIn the present study, the fate of trivalent chromium (Cr(III)) during ozonation of ultrapurified water and wastewater effluent was investigated. In experiments conducted in phosphate buffered ultrapurified water, O3 alone in excess was inefficient to oxidize Cr(III) (only about 10–15% of total Cr(III) content), while in presence of the secondary oxidant, OH radical, almost all Cr(III) was oxidized to hexavalent chromium (Cr(VI)). In a wastewater effluent, spiked with Cr(III), only about 10–20% of Cr(III) was oxidized with specific ozone doses in the range 0.15–1.5 gO3/gDOC, although O3 and OH radical were both available for reaction. Cr(VI) formation was monitored in parallel with the abatement of some common micropollutants, reacting with differing apparent second-order rate constants with ozone, decreasing in the order carbamazepine>> benzotriazole> atrazine> p-chlorobenzoic acid (pCBA). Carbamazepine and benzotriazole were abated to >80% for specific O3 doses of 0.3 gO3/gDOC and 0.8 gO3/gDOC, respectively. The more ozone-resistant compounds (atrazine and pCBA) required a specific ozone dose of about 1.25 gO3/gDOC for the same relative abatement. At this specific ozone dose (i.e., 1.25 gO3/gDOC), only about 20% of Cr(III) was oxidized to Cr(VI), whereas only 10% of Cr(III) was oxidized to Cr(VI) at a more realistic specific ozone dose for enhanced wastewater treatment for micropollutant abatement (0.5 gO3/gDOC). Therefore, for typical Cr(III) levels in municipal wastewaters, effluent ozonation only leads to toxicologically insignificant Cr(VI) concentrations.

Tun formation is not a prerequisite for desiccation tolerance in the marine tidal tardigradeEchiniscoides sigismundi

The so-called ‘tun’ state is best known from limno-terrestrial tardigrades and rotifers that rely on this compact body shape for anhydrobiotic survival. Little is known of tun formation in marine species and the evolutionary origin of the state is presently unknown. Here, we investigate desiccation tolerance and tun formation in the marine tidal echiniscoidean tardigrade, Echiniscoides sigismundi (M. Schultze, 1865). Groups of approximately 20 E. sigismundi sampled from Lynaes (Denmark) were dehydrated on filter paper from seawater as well as ultrapurified water and kept for 48 h at 5 °C, after which they were rehydrated in seawater. The activity and behaviour of the tardigrades was examined under a light microscope, whereas scanning electron microscopy was used for high-resolution three-dimensional imaging. When dehydrated from seawater, E. sigismundi enters a tun, however, when exposed to ultrapurified water, the tardigrade swells and becomes incapable of movement, and thus incapable of tun formation. Nonetheless, E. sigismundi tolerates being dehydrated from ultrapurified water, revealing an exceptional and unparalleled resilience towards losing structural integrity. Our results confirm previous investigations, which suggest that tun formation relies on a functional musculature. They further suggest that tun formation may have evolved as a response to elevated external pressure rather than desiccation per se.

Ultrasensitive determination of carbendazim in water and orange juice using a carbon paste electrode

ABSTRACTA carbon paste electrode was used for the electrochemical quantification of carbendazim in water and orange juice samples. Carbendazim oxidation on the electrode surface was found to be controlled by adsorption. The novel electrochemical procedure for carbendazim quantification employed differential pulse voltammetry using a carbon paste electrode under optimal conditions. Carbendazim oxidation currents were linear at concentrations of 2.84 to 45.44 µg L−1, with a limit of detection of 0.96 µg L−1. The proposed method was applied to carbendazim quantification in ultrapurified water, river water, and orange juice. Recovery rates in water and orange juice samples were in the 97%–101% range, indicating that the method can be employed to determine carbendazim in these matrices, with advantages including shorter analysis time and lower cost than routine methods such as chromatography or spectroscopy. The electrode showed good reproducibility, remarkable stability, and especially good surface renewability by simple mechanical polishing. The recovery rates observed were highly concordant with those obtained for high-performance liquid chromatography, having a relative standard deviation of less than 1.3%.

A multi-targeted liquid chromatography–mass spectrometry screening procedure for the detection in human urine of drugs non-prohibited in sport commonly used by the athletes

This work presents an analytical method for the simultaneous analysis in human urine of 38 pharmacologically active compounds (19 benzodiazepine-like substances, 7 selective serotonin reuptake inhibitors, 4 azole antifungal drugs, 5 inhibitors of the phosphodiesterases type 4 and 3 inhibitors of the phosphodiesterase type 5) by liquid-chromatography coupled with tandem mass spectrometry. The above substances classes include both the most common “non banned” drugs used by the athletes (based on the information reported on the “doping control form”) and those drugs who are suspected to be performance enhancing and/or act as masking agents in particular conditions. The chromatographic separation was performed by a reverse-phase octadecyl column using as mobile phases acetonitrile and ultra-purified water, both with 0.1% formic acid. The detection was carried out using a triple quadrupole mass spectrometric analyser, positive electro-spray as ionization source and selected reaction monitoring as acquisition mode. Sample pre-treatment consisted in an enzymatic hydrolysis followed by a liquid–liquid extraction in neutral field using tert-butyl methyl-ether. The analytical procedure, once developed, was validated in terms of sensitivity (lower limits of detection in the range of 1–50ngmL−1), specificity (no interferences were detected at the retention time of all the analytes under investigation), recovery (≥60% with a satisfactory repeatability, CV % lower than 10), matrix effect (lower than 30%) and reproducibility of retention times (CV% lower than 0.1) and of relative abundances (CV% lower than 15). The performance and the applicability of the method was evaluated by analyzing real samples containing benzodiazepines (alprazolam, diazepam, zolpidem or zoplicone) or inhibitors of the phosphodiesterases type 5 (sildenafil or vardenafil) and samples obtained incubating two of the phosphodiesterases type 4 studied (cilomilast or roflumilast) with pooled human liver microsomes. All the parent compounds, together with their main phase I metabolites, were clearly detected using the analytical procedures here developed.

Development and validation of a liquid chromatography–mass spectrometry procedure after solid-phase extraction for detection of 19 doping peptides in human urine

A liquid chromatography–tandem mass spectrometry method was developed and used to simultaneously detect 19 small peptide hormones prohibited in sport and their main metabolites in urine after solid-phase extraction. Detection was achieved using a triple-quadrupole mass spectrometric detector coupled with an electrospray ionization interface after chromatographic separation with an octadecyl column based on fused-core particle technology. Sample pretreatment was performed by solid-phase extraction. The extraction procedure was optimized by comparison of different sorbents and washing/elution protocols. The best results were obtained using a mixed-mode weak cation exchange sorbent, two washing steps (ultrapurified water and methanol), and elution using 300 mM ammonium formate in 25 % ammonia/methanol (10/90) or 25 % ammonia/10 % formic acid/methanol (8/12/80). The procedure was validated in terms of sensitivity (lower limits of detection: 0.05–2.0 ng/ml depending on the target analyte), specificity, recovery [>60 %, coefficient of variation (CV) <15 % except for TB500 17–23 fragment, AOD9604, and ARA290 for which recovery was <50 %), ion suppression/enhancement (<35 %), robustness, carryover, stability of the target analytes [stable for at least for 2 days (25 °C, 2 weeks (4 °C), 2 months (−20 °C)], and repeatability of retention times (CV <0.1 %) and relative abundances of the selected ion transitions (CV <15 %). The suitability of the method was confirmed by analyzing spiked and excreted urines, the latter collected after intravenous injection of 0.1 mg of GHRP-2.