Electrochemically Mediated Atom Transfer Radical Polymerization Driven by Alternating Current

Alternating current (AC) and pulsed electrolysis are gaining traction in electro(organic) synthesis due to their advantageous characteristics. We employed AC electrolysis in electrochemically mediated Atom Transfer Radical Polymerization (eATRP) to facilitate the regeneration of the activator CuI complex on Cu0 electrodes. Additionally, Cu0 served as a slow supplemental activator and reducing agent (SARA ATRP), enabling the activation of alkyl halides and the regeneration of the CuI activator through a comproportionation reaction. We harnessed the distinct properties of Cu0 dual regeneration, both chemical and electrochemical, by employing sinusoidal, triangular, and square-wave AC electrolysis alongside some of the most active ATRP catalysts available. Compared to linear waveform (DC electrolysis) or SARA ATRP (without electrolysis), pulsed and AC electrolysis facilitated slightly faster and more controlled polymerizations of acrylates. The same AC electrolysis conditions could successfully polymerize eleven different monomers across different mediums, from water to bulk. Moreover, it proved effective across a spectrum of catalyst activity, from low-activity Cu/2,2-bipyridine to highly active Cu complexes with substituted tripodal amine ligands. Chain extension experiments confirmed the high chain-end fidelity of the produced polymers, yielding functional and high molecular-weight block copolymers. SEM analysis indicated the robustness of the Cu0 electrodes, sustaining at least 15 consecutive polymerizations.

Sulfated polysaccharides from seaweed as a supplement to Prochilodus brevis sperm freezing medium

BACKGROUND

Using sulfated polysaccharides (SP) in fish sperm freezing medium promotes cell maintenance.

OBJECTIVE

To evaluate the effect of different SP concentrations, extracted from two seaweeds (Gracilaria domingensis and Ulva fasciata), as a supplement to the sperm freezing medium of Prochilodus brevis.

MATERIALS AND METHODS

Five semen pools were diluted in a solution composed of 5% glucose, 10 % dimethyl sulfoxide (DMSO) and different SP concentrations (0, 0.5, 1.0, 1.5, 2.0, 2.5 or 3.0 mg/mL). The samples were cryopreserved and, after 7 days, rewarmed and analyzed for morphology, plasma membrane integrity, DNA integrity, mitochondrial activity and sperm kinetics [total motility, progressive motility, curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP), linearity (LIN), and wobble (WOB)].

RESULTS

There was no interaction between seaweed and SP concentrations. Similar effects were observed with SP extracted from the two seaweeds, regardless of concentration. When comparing the SP concentrations, regardless of the seaweed, 1.0 mg/mL SP showed better results for VCL and VSL. For VAP and WOB, 1.0 mg/mL SP showed better results, but differed from 3.0 mg/mL. LIN followed the same pattern, but differed from SP at 2.5 and 3.0 mg/mL. For progressive motility, 1.0 mg/mL G. domingensis showed superior results compared to the control. For mitochondrial activity, G. domingensis was superior to U. fasciata, regardless of concentration. The lowest concentrations (0.5 and 1.0 mg/mL) showed the best results, regardless of the seaweed. However, the control was superior to all treatments tested.

CONCLUSION

G. domingensis SP at the lowest concentrations might be a potential supplement to the P. brevis freezing medium. doi.org/10.54680/fr22210110412.

Adrenal incidentaloma as a novel independent predictive factor for periodontitis

PURPOSE

There are no data regarding periodontal derangements in patients with adrenal incidentalomas (AI). We assessed the frequency and severity of periodontitis in patients with AI [non-functioning adrenal incidentaloma (NFAI) and possible autonomous cortisol secretion (ACS)] and compared with individuals with normal adrenal.

METHODS

A cross-sectional study evaluated thirty-five individuals with AI and 26 controls. NFAI and possible ACS diagnosis was based on the current guidelines: NFAI [cortisol levels after 1 mg dexamethasone suppression test (1 mg-DST) ≤ 1.8 µg/dL (≤ 50 nmol/L)]; possible ACS [cortisol levels after 1 mg-DST 1.9-5.0 µg/dL (51-138 nmol/L)]. Sociodemographic data were collected, and a full-mouth periodontal evaluation was performed.

RESULTS

There was no significant difference between groups regarding age, sex, income, ethnicity, education level, smoking, body mass index, dysglycemia, and arterial hypertension. Patients with AI exhibited worse periodontal conditions than controls for the following periodontal clinical parameters: mean percentage of probing pocket depth (PPD) and clinical attachment level (CAL) ≥ 5 mm (p < 0.001 and p = 0.006, respectively). Patients with NFAI and possible ACS showed higher gingival bleeding index (p = 0.014), bleeding on probing (p < 0.001), and CAL (p < 0.001) means compared to controls. The frequencies of periodontitis were 72.7% in patients with NFAI, 84.6% in possible ACS, and 30.8% in controls (p = 0.001). Periodontitis was more severe in patients with possible ACS than NFAI and controls. Patients with NFAI and possible ACS exhibited odds ratio for periodontitis of 4.9 (p = 0.016) and 8.6 (p = 0.02), respectively.

CONCLUSION

Patients with AI have higher frequency and severity of periodontitis than controls. The presence of AI was an independent predictive factor for periodontitis.

The effect of glycosaminoglycans, extracted from the skin of tilapia, in the sperm freezing medium of Colossoma macropomum

BACKGROUND

Sulfated polysaccharides from the skin of Nile tilapia (Oreochromis niloticus), added to the tambaqui (Colossoma macropomum) semen diluting medium, can be potential antioxidants and promote the maintenance of sperm quality.

OBJECTIVE

To evaluate the use of different concentrations of glycosaminoglycans (GAGs) from the skin of Nile tilapia as a supplement in two cryogenic media for tambaqui semen.

MATERIALS AND METHODS

Tambaqui males received a single dose of pituitary carp extract. The semen was collected for pool analysis and, later, cryopreserved in liquid nitrogen. The pools were diluted and frozen in a solution containing fish-specific powdered coconut water (ACP-104) and 10% DMSO or 5% Glucose and 10% DMSO and supplemented with different concentrations of GAGs. The controls had no GAGs addition. After 45 days, the samples were thawed by immersion in a water bath and evaluated for membrane and DNA integrity, morphology and sperm kinetics.

RESULTS

The parameters of linearity (LIN), straightness (STR) and DNA integrity of sperm frozen in 5% Glucose showed better results than ACP-104. For membrane integrity, concentrations of 0 and 1.0 mg/mL were better than 5 mg/mL. Semen motility in 5% Glucose showed superior results at concentrations lower than 5 mg/mL of GAGs. For VCL and VAP, in ACP-104, 3.0 mg/mL exceeded the other treatments. In 5% Glucose, for VCL, 4.0 mg/mL showed the lowest results compared to concentrations of <3.5 mg/mL and, for VAP, it also differed from 4.5 mg/mL CONCLUSION: Therefore, the skin of Nile tilapia has GAGs, in low concentrations, capable of improving the post-thawed sperm quality of tambaqui, especially in 5% Glucose medium.

Liquid salts as eco-friendly solvents for atom transfer radical polymerization: a review

Liquid salts, comprising ionic liquids and eutectic mixtures, are organic compounds/mixtures characterized by a low melting point that have been emerging as a very promising eco-friendly solvent for atom transfer radical polymerization.

Characterization of tomato processing by-product for use as a potential functional food ingredient: nutritional composition, antioxidant activity and bioactive compounds

Tomato pomace, a by-product generated during tomato processing, was collected at a large tomato processing industry. The by-product was mainly constituted of tomato skin (61.5%), and presented high moisture content (66.58 g.100g^-1 wet basis). Among the nutrients, the highest content was of dietary fibre, followed by proteins and fat (50.74, 20.91, 14.14 g.100g^-1 d.w., respectively). The pomace has high in vitro antioxidation capacity, especially when measured with the TEAC assay (224.81 μmol Trolox equivalent 100g^-1 d.w.). This is due especially to the high amount of lycopene remaining in the by-product after processing (446.9 μg.g^-1 d.w). The waste was fractioned into skin and seed fractions by sedimentation, resulting in the increase of lycopene yield by 55%, when using skin fraction as the source material in place of the whole pomace. This by-product shows great potential for being used as a source of the ingredients of high nutritional value, especially dietary fibre and lycopene.

Cardiopulmonary bypass alters the pharmacokinetics of propranolol in patients undergoing cardiac surgery

The pharmacokinetics of propranolol may be altered by hypothermic cardiopulmonary bypass (CPB), resulting in unpredictable postoperative hemodynamic responses to usual doses. The objective of the present study was to investigate the pharmacokinetics of propranolol in patients undergoing coronary artery bypass grafting (CABG) by CPB under moderate hypothermia. We evaluated 11 patients, 4 women and 7 men (mean age 57 +/- 8 years, mean weight 75.4 +/- 11.9 kg and mean body surface area 1.83 +/- 0.19 m(2)), receiving propranolol before surgery (80-240 mg a day) and postoperatively (10 mg a day). Plasma propranolol levels were measured before and after CPB by high-performance liquid chromatography. Pharmacokinetic Solutions 2.0 software was used to estimate the pharmacokinetic parameters after administration of the drug pre- and postoperatively. There was an increase of biological half-life from 4.5 (95% CI = 3.9-6.9) to 10.6 h (95% CI = 8.2-14.7; P < 0.01) and an increase in volume of distribution from 4.9 (95% CI = 3.2-14.3) to 8.3 l/kg (95% CI = 6.5-32.1; P < 0.05), while total clearance remained unchanged 9.2 (95% CI = 7.7-24.6) vs 10.7 ml min(-1) kg(-1) (95% CI = 7.7-26.6; NS) after surgery. In conclusion, increases in drug distribution could be explained in part by hemodilution during CPB. On the other hand, the increase of biological half-life can be attributed to changes in hepatic metabolism induced by CPB under moderate hypothermia. These alterations in the pharmacokinetics of propranolol after CABG with hypothermic CPB might induce a greater myocardial depression in response to propranolol than would be expected with an equivalent dose during the postoperative period.

A micromethod for quantitation of debrisoquine and 4-hydroxydebrisoquine in urine by liquid chromatography

We describe a new simple, selective and sensitive micromethod based on HPLC and fluorescence detection to measure debrisoquine (D) and 4-hydroxydebrisoquine (4-OHD) in urine for the investigation of xenobiotic metabolism by debrisoquine hydroxylase (CYP2D6). Four hundred microl of urine was required for the analysis of D and 4-OHD. Peaks were eluted at 8.3 min (4-OHD), 14.0 min (D) and 16.6 min for the internal standard, metoprolol (20 microg/ml). The 5-microm CN-reverse-phase column (Shimpack, 250 x 4.6 mm) was eluted with a mobile phase consisting of 0.25 M acetate buffer, pH 5.0, and acetonitrile (9:1, v/v) at 0.7 ml/min with detection at lambdaexcitation = 210 nm and lambdaemission = 290 nm. The method, validated on the basis of measurements of spiked urine, presented 3 ng/ml (D) and 6 ng/ml (4-OHD) sensitivity, 390-6240 ng/ml (D) and 750-12000 ng/ml (4-OHD) linearity, and 5.7/8.2% (D) and 5.3/8.2% (4-OHD) intra/interassay precision. The method was validated using urine of a healthy Caucasian volunteer who received one 10-mg tablet of Declinax(R), po, in the morning after an overnight fast. Urine samples (diuresis of 4 or 6 h) were collected from zero to 24 h. The urinary excretion of D and 4-OHD, Fel (0-24 h), i.e., fraction of dose administered and excreted into urine, was 6.4% and 31.9%, respectively. The hydroxylation capacity index reported as metabolic ratio was 0.18 (D/4-OHD) for the person investigated and can be compared to reference limits of >12.5 for poor metabolizers (PM) and <12.5 for extensive metabolizers (EM). In parallel, the recovery ratio (RR), another hydroxylation capacity index, was 0.85 (4-OHD: SigmaD + 4-OHD) versus reference limits of RR <0.12 for PM and RR >0. 12 for EM. The healthy volunteer was considered to be an extensive metabolizer on the basis of the debrisoquine test.

A simple HPLC-fluorescence method for the measurement of R,S-sotalol in the plasma of patients with life-threatening cardiac arrhythmias

R,S-sotalol, a ss-blocker drug with class III antiarrhythmic properties, is prescribed to patients with ventricular, atrial and supraventricular arrhythmias. A simple and sensitive method based on HPLC-fluorescence is described for the quantification of R,S-sotalol racemate in 500 microl of plasma. R,S-sotalol and its internal standard (atenolol) were eluted after 5.9 and 8.5 min, respectively, from a 4-micron C18 reverse-phase column using a mobile phase consisting of 80 mM KH2PO4, pH 4.6, and acetonitrile (95:5, v/v) at a flow rate of 0.5 ml/min with detection at lambdaex = 235 nm and lambdaem = 310 nm, respectively. This method, validated on the basis of R,S-sotalol measurements in spiked blank plasma, presented 20 ng/ml sensitivity, 20-10,000 ng/ml linearity, and 2.9 and 4.8% intra- and interassay precision, respectively. Plasma sotalol concentrations were determined by applying this method to investigate five high-risk patients with atrial fibrillation admitted to the Emergency Service of the Medical School Hospital, who received sotalol, 160 mg po, as loading dose. Blood samples were collected from a peripheral vein at zero, 0.5, 1.0, 1.5, 2.0, 3.0, 4. 0, 6.0, 8.0, 12.0 and 24.0 h after drug administration. A two-compartment open model was applied. Data obtained, expressed as mean, were: C MAX = 1230 ng/ml, T MAX = 1.8 h, AUC T = 10645 ng h-1 ml-1, Kab = 1.23 h-1, alpha = 0.95 h-1, ss = 0.09 h-1, t((1/2))ss = 7.8 h, ClT/F = 3.94 ml min-1 kg-1, and Vd/F = 2.53 l/kg. A good systemic availability and a fast absorption were obtained. Drug distribution was reduced to the same extent in terms of total body clearance when patients and healthy volunteers were compared, and consequently elimination half-life remained unchanged. Thus, the method described in the present study is useful for therapeutic drug monitoring purposes, pharmacokinetic investigation and pharmacokinetic-pharmacodynamic sotalol studies in patients with tachyarrhythmias.

Enantioselective analysis of metoprolol in plasma using high-performance liquid chromatographic direct and indirect separations: applications in pharmacokinetics

Direct enantioselective separation on chiral stationary phases and indirect separation based on the formation of diastereomeric derivatives were developed and compared for the HPLC analysis of R(+) and S(-)-metoprolol in human plasma. Plasma samples prepared using solid-phase extraction columns or liquid-liquid extraction were directly analyzed on a Chiralpack AD or on a Chiralcel OD-H columns, respectively. S-(-)-menthyl choroformate was also used to yield diastereomeric derivatives resolved on a RP-8 column. The methods were employed to determine plasma concentrations of metoprolol enantiomers in a pharmacokinetic study of single dose administration of racemic metoprolol to a healthy Caucasian volunteer phenotyped as extensive metabolizer of debrisoquine. The correlation coefficients among enantioselective metoprolol plasma concentrations (5-223 ng/ml) obtained by the three methods were equal or higher than 0.99. The direct method that employed the chiral column Chiralpak AD may be considered the most sensitive, although the three methods demonstrated interchangeable use in the pharmacokinetic investigation.