One alternative to improve electrochemical performance and long-term applicability in microbial bioelectrochemical systems (BESs) is the use of porous ceramic electrodes. In this work, electrodes of ...polymer-derived ceramics based on poly(silsesquioxanes) are synthesized, tailoring the properties by varying pyrolysis temperatures and incorporating conductive phases. Carbon (graphite, carbon black) and metal-based (stainless steel/Cu grids, Co/Ni particles) materials are incorporated into the silicon oxycarbide (SiOC) matrix. The influence of pyrolysis temperature and incorporation of conductive materials on functional properties and electrical conductivity is discussed. Furthermore, this study provides the first investigation of biofilm development on SiOC-based ceramic surfaces with
Escherichia coli
and
Bacillus cereus
. SiOC-based ceramics with DC conductivity values at room temperature in the semiconductor range (0.044–0.385 S cm
−1
) were obtained, with the highest values achieved by Co and Ni particles incorporation and in situ formation of CNTs. Adjustment in hydrophilicity and specific surface areas (6.21–263.45 m
2
g
−1
) is realized by the pyrolysis. The biofilm studies reveal adhesion in the first 2 h for most of the surfaces, with higher bacterial adhesion and biofilm formation with the
E. coli.
The biocompatibility in terms of bacterial attachment and conductivity values comparable to a commercial carbon felt support the applicability of the developed SiOC-based materials as promising new class of electrodes for BES.
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•Novel polymer-derived ceramic based anode materials applied in MFCs.•PDC-based anodes with porous structures and hydrophilic surfaces were developed.•Maximum power density of 211 mW ...m−2 with 85% COD removal.
The applicability of a new class of ceramic materials in Microbial Fuel Cells (MFCs) was investigated, targeting the development of cost-effective anode materials with long-term durability. In this work, silicon oxycarbide (SiOC)-based porous anodes were prepared by the polymer-derived ceramics (PDCs) route, using poly(methyl silsesquioxane) and poly(methyl phenyl silsesquioxane) as precursors while incorporating carbonaceous fillers (graphite and carbon black) and metal precursor (NiCl2). Tape casting was used in the manufacturing followed by pyrolysis at 1000 °C under nitrogen atmosphere. The interior structure and surface morphology were characterized with scanning electron microscopy (SEM), nitrogen adsorption, vapor adsorption, and contact angle measurements. The developed anodes were tested in MFC with aqueous cathode configuration using a low-cost clayware cylinder as the anodic chamber. The performance of MFC using PDC-based anodes was compared with MFC having carbon felt as anode material, which showed a two-fold increase in power density (211 and 111 mW m−2, respectively) and normalized energy recovery in former and also demonstrated chemical oxygen demand (COD) removal efficiency of about 85%. The improved performance of the PDC-based anodes is attributed to its porous structure, hydrophilic surface, and high specific surface area (39.89 m² g−1). The biocompatibility was confirmed by biofilm growth on the surfaces, while a sufficient electrical conductivity (0.10–0.18 S cm−1) makes it superior electrode material for application in MFCs.
Porous SiOC tapes were studied as anodes for bioelectrochemical system (BES) using Geobacter spp. as an electroactive microorganism (EAM). The ceramic anodes were produced by tape‐casting of ...poly(silsesquioxanes), tailoring the surface properties by incorporating graphite and carbon black, and changing the pyrolysis temperature. By varying these parameters, the specific surface area, the hydrophilicity, and the roughness were adjusted, with the pyrolysis temperature playing a major role. When used as anodes at 0.2 V vs. Ag/AgCl sat. KCl in the BES, maximum current densities relative to the geometric surface area (jGSA) up to 5.8 A m−2 were achieved. Microbial community analysis of the biofilm shows the dominant presence of Geobacter spp. as the EAM. Benchmarking the performance of the anodes of this study with anodes using the same EAM demonstrates that porous SiOC anodes are a promising class of materials, as they show jGSA comparable to carbon‐based anodes.
Ceramic electrodes do not break but may allow breakthrough: Electron‐conducting SiOC anodes are fabricated and the impact of the surface properties and pore structure on their performance for Geobacter spp. biofilm anodes is analyzed. Surface hydrophilicity is shown to have the greatest influence. When benchmarked with different systems under similar conditions, SiOC anodes show comparable performance to conventional carbon anodes with great adaptability of material properties.
The treatment of platinum resistant/refractory epithelial ovarian cancer (EOC) is a challenge for oncologists. One of the most utilized drugs in these patients is pegylated liposomal doxorubicin ...(PLD). As PLD is active only in a small subset of patients and causes side effects, selection of responsive patients is an unmet need and might be guided by the status of the DNA topoisomerase II alpha (TOP2A) that is poisoned by the drug.
From 176 ovarian cancers treated in three institutions, we selected 38 patients treated with PLD monotherapy as second/third line of treatment. TOP2A gene copies were measured using Fluorescent In Situ Hybridization (FISH) and expression evaluated using immunohistochemistry. Patients' derived xenografts (PDXs) of ovarian cancers were used to assess the correlation between TOP2A protein expression and response to PLD.
Clinical data showed that TOP2A gene gain that is paralleled by increased expression of the protein, was associated with a higher probability of clinical benefit from PLD. Treatment of PDXs demonstrated that only xenografts showing a high percentage of TOP2A expressing cells underwent tumor shrinkage when treated with PLD.
These data show that TOP2A gene gain and protein over-expression might predict activity of PLD in platinum resistant/refractory EOC.
Cobalt/nickel-containing SiOC-based porous ceramic electrocatalysts were prepared by pyrolysis of poly(methyl silsesquioxane) and poly(methyl phenyl silsesquioxane) as preceramic precursors combined ...with graphite and Co/Ni metal salts at 1000 °C in an atmosphere of nitrogen. Subsequently, the Co/Ni–SiOC materials were N-doped using dicyandiamide (DCDA) as a nitrogen source and pyrolysed at 800 °C in an inert atmosphere. The structural properties and composition of the catalysts were characterised by scanning electron microscopy (SEM), X-ray diffraction, X-ray photoelectron spectroscopy (XPS) and N 2 adsorption analysis. The evaluation of the polymer-derived SiOC(N) ceramic electrocatalysts as a new class of catalysts for the oxygen reaction reduction (ORR) was carried out by the rotating disk electrode (RDE) method under acidic, neutral and alkaline conditions. The O 2 reduction studies revealed that the N-doped materials exhibited enhanced ORR performance, confirming the positive influence of the nitrogen functionalities introduced into the catalysts. The Co-containing N-doped SiOC catalyst exhibited significantly higher ORR activity compared with the studied materials along with the highest electron transfer number in all the studied solutions. Long-term ORR performance testing indicated that the durability of this catalyst was superior as compared to that of commercial Pt/C. These observations suggest that the Co-containing N-doped SiOC catalyst is a promising cathode material for fuel cells (FCs) and microbial FC devices.
RESUMO O objetivo do trabalho foi avaliar as características produtivas e nutricionais do capim- xaraés inoculado com bactérias diazotróficas associativas, em primeiro cultivo em Latossolo Vermelho ...do Cerrado. O experimento foi realizado em casa de vegetação. O delineamento experimental foi inteiramente ao acaso, constituído por fatorial 6x3: três estirpes de bactérias diazotróficas associativas (MTAz8, MTH2 e Y2), uma combinação das estirpes MTAz8 e MTH2, adubação nitrogenada e testemunha absoluta, e três cortes (30, 60 e 90 dias), em cinco repetições. A inoculação foi feita por meio da inserção de uma alíquota de 5mL de caldo bacteriano contendo 108 células mL-1 no solo próximo ao sistema radicular. As variáveis avaliadas foram: massa seca da parte aérea, porcentagem de proteína bruta, acúmulo e concentração de nitrogênio na parte aérea e determinação do número de bactérias diazotróficas do solo. No tratamento adubado com nitrogênio, a produção de massa seca aumentou ao longo dos cortes. Entre as estirpes de bactérias associativas, a Y2 apresentou maior acúmulo de nitrogênio e maior população de bactérias no meio de cultura LGI. As características nutricionais do capim-xaraés decaíram à medida que foram realizados os cortes.
Tricyclic antidepressives, such as imipramine, indirectly induce ejaculation by increasing the noradrenaline concentration, which triggers an α-adrenergic response, whereas α-adrenergic agonists, ...such as xylazine and detomidine, directly trigger ejaculation by activating the α-1 adrenergic receptors. Furthermore, serum oxytocin concentrations in stallions increase drastically before ejaculation, but decline immediately thereafter, implicating the role of this hormone in emission. The objectives of the present study were to: 1) compare the efficiency of various protocols for inducing ex copula ejaculation in stallions, 2) evaluate the benefits of including oxytocin in the protocols, and 3) compare the semen characteristics of ex copula versus in copula ejaculates. Nine protocols were used to induce ex copula ejaculation using various combinations of xylazine (X; 0.66 mg/kg, iv); oxytocin (O; 20 IU, iv), imipramine (I; 3 mg/kg, orally), and detomidine (D; 0.02 mg/kg, iv). Imipramine was given 2 h prior to the administration of α-adrenergic agonist (detomidine or xylazine) and oxytocin. If ejaculation did not occur within 10 min after treatment with an α-adrenergic agonist, a half-dose of the same product was injected. Twelve sexually mature stallions (6–26 y) were used; 9 of 12 stallions responded to the treatment. Two stallions responded to X or XO, four stallions responded to IX and IXO, one stallion responded to DO, and five responded to IDO. Stallions that responded to detomidine did not respond to xylazine. No stallion ejaculated in response to D, ID, or IO. Erections and masturbation occurred only in imipramine-treated stallions. Sperm quality was similar among all the protocols and was not significantly different from those in in copula ejaculates collected with an artificial vagina. In a separate trial, none of these protocols induced ex copula ejaculation in 2–3 y old stallions. The side effects included sialorrhea after imipramine administration in all the stallions and sedation after administration of xylazine or detomidine. In conclusion, the new protocol, IDO, and the traditional protocol, IX, had similar results, with IDO being a useful alternative protocol in stallions for which IX was not effective. Therefore, attempts using both the protocols are encouraged, as stallions that ejaculated upon administration of detomidine did not ejaculate when xylazine was administered, whereas those that responded to xylazine did not respond to detomidine.
•An alternative protocol for pharmacologically-induced ejaculation was identified.•The addition of oxytocin with detomidine increase the ejaculation rates.•Protocols used in the animal’s stall with a quiet environment was fundamental for the success of the treatment.
•The pH of mammary gland secretions was the factor with the highest association with impending parturition in jennies.•Calcium of mammary gland secretions displayed a sensitivity and specificity of ...71% and 85% for foaling in 24 hours.•Electrolytes of mammary gland secretions increased with the impending foaling, except for Na+•There were weak to moderate associations between pH and electrolytes in the mammary gland secretions of jennies.•The majority of jennies displayed a slow reducing pH profile of mammary gland secretions.
The objectives of this study were to determine (i) the usefulness of serial assessment of mammary gland electrolytes concentrations and correspondent pH to detect impending parturition in jennies; and (ii2) the associations between mammary gland secretions, and gestation length, foal sex, maternal, placental, and foal birth weights. Multiparous jennies (n = 37) were monitored daily from 350 to 355 days of gestation until parturition. The pH of mammary gland secretions was assessed daily with a hand-held device. Aliquots of mammary secretions were frozen daily and then retrospectively assessed for electrolyte concentrations (Ca2+, Mg2+, K+, and Na+) with an automated analyzer from five days until the last sampling pre-partum. Mammary gland electrolytes and pH were analyzed with mix-models. The gestational length, newborn, maternal, and fetal membranes weights were analyzed with t-test grouped by foal's sex. Associations across all variables were assessed with Pearson's coefficient of correlation. Sensitivity, specificity, and negative predictive value (NPV) and positive predictive values (PPV) were evaluated for pH (≤ 6.4), Ca2+ (>10 mmol/L), and a combination of both. Each jenny had pH profiles assessed visually and classified as fast pH drop (1), slow pH drop (2), and alkaline pH (3) as previously described for horses. The overall gestation length was 374 ± 8.7 days, ranging from 357 to 390 days. There were no differences for gestation lengths for jennies delivering colts (374 ± 2.1 range 357–385 days), versus the ones delivering fillies (373 ± 2.3 range 358–390 days) (P > .05). Of all the foals, there were 61.8% colts and 38.2% fillies. The ratio of foal birthweight with the dam's bodyweight was 9.7%, and the ratio with fetal membranes was 11%. The majority of parturitions happened during the night (91.9%). There was a significant reduction in Na+ and an increase in Ca2+, Mg2+, and K+ concentrations leading to foaling. The pH showed a 90% sensitivity for foaling within 24 hours, whereas the specificity was 70%, and the PPV and NPV values were 40% and 97%. Of interest, Ca2+ (>10 mmol/l) displayed a sensitivity and specificity of 71% and 85%, whereas the PPV and NPV were 72% and 84%. In the present study, jennies exhibited profiles 1 to 3 as previously described for mares. Herein, 65% of the jennies displayed profile 2 and foaled with a mean acidic pH of 6.4 ± 0.02. Conversely, 32% of the jennies showed a fast reduction in the pH of mammary secretion (profile 1) from day -1 (7.3 ± 0.2) to the day of foaling with an average pH of 6.6 ± 0.08. One jenny foaled with high and alkaline pH (i.e., 7.5). There were weak and negative correlations between pH and Ca2+, Mg2+, and K+ (P < .05). In addition, Ca2+ displayed a weak but significant correlation with Mg2+, Na+, and K+. In conclusion, daily pH measurements of the mammary gland secretions can predict foaling in jennies, whereas Ca2+ was not as useful. Contrary to horses that most mares present a fast pH profile, most jennies showed a slow pH profile. The sex of foal did not affect the gestational length and fetal/maternal and fetal membrane proportions in donkeys.
The aim of this study was to assess the addition of 2% sodium caseinate in a commercial egg yolk‐based medium in frozen ovine semen. Eight Dorper males were used for the study. The ejaculate was ...divided into two portions and frozen without (G1) or with the addition of 2% sodium caseinate (G2). Kinetic parameters were evaluated using CASA (computer‐assisted sperm analysis), and membrane and acrosome integrity as well as oxidative stress were assessed using flow cytometry. After thawing, a thermoresistance test was conducted at time points T0 and T90. For the fertility test, 100 ewes were inseminated with semen from two rams selected based on in vitro parameters, one with good post‐thaw quality (+70% total motility) and the other with low post‐thaw quality (−55% total motility). For the fertility test, the females were divided into 4 groups for insemination: low‐quality ram without caseinate (GBS = 25) and with caseinate (GBC = 25), and high‐quality ram without caseinate (GAS = 25) and with caseinate (GAC = 25). Regarding the results of sperm kinetics, there was a statistically significant difference in the parameters of average path velocity (VAP) and curvilinear velocity (VCL) between the group frozen with BotuBov and the group with added caseinate. At time point T90, straight‐line velocity maintained a trend (p < .06), with BotuBov® (BB group) being superior to caseinate this time, and in the linearity parameter, caseinate was superior to BotuBov®. Flow cytometry analysis showed no difference between any of the evaluated tests. In the fertility test, there was no statistically significant difference in the pregnancy rate between the BotuBOV® group (23%, 11/48) and the sodium caseinate group (BC group) (33%, 17/52), and no differences were observed in the male versus diluent interaction (p = .70). In conclusion, sodium caseinate supplementation did not influence sperm kinetic parameters and the fertility of sheep.
•Nojack failed to ejaculate using an artificial vagina and a jenny in estrus Testicular volume varies with equations used to estimate its shape.•Copulatory behavior parameters did not vary across ...collections.•Semen motility parameters did not change across collection days, suggesting that sexual rest did not affect motility parameters.•Dezhou donkeys have spermatogenic efficiency, able to produce up to 50 breeding doses per collection.
This study aimed to assess the sexual behavior of jacks mounting jennies in estrus and determine the daily sperm output (DSO) and spermatogenic efficiency using two equations to calculate testicular volume (TV). Eight sexually rested mature jacks, aging 5 to 10 years old, had semen collected once a day for 10 consecutive days using jennies in good standing estrus for mounting. Sexual behavior and semen parameters were assessed during each collection. Testicular measurements of height, width, and length were taken immediately before the first semen collection, and these measurements were used to calculate TV. After that, the TV was used to predict the DSO. The average total sperm number (TSN) obtained on days 8 to 10 was deemed the actual DSO. Differences in the predicted vs. the actual DSO were used to calculate the spermatogenic efficiency. In addition, the actual DSO was also used to calculate the number of inseminating doses a jack could produce for both on- and off-site breeding. Jack's sexual behavior and sperm motility did not vary across collection days. Sperm concentration and TSN reduced over time (P < .05). The actual DSO was 9.1 ± 4.1 billion, and the predicted DSO varied from 4.7 to 18 billion. Spermatogenic efficiency varied from 50 to 150% based on jack and the equation used to calculate TV. The number of inseminating doses ranged from 15 to 47 at 300-500 million progressively motile sperm (pms)/dose for on-site breeding. In contrast, the number of breeding doses with cooled-shipped semen (1 billion pms/dose) varied from 4 to 14 doses across donkeys. In conclusion, sexual behavior was not affected by daily semen collections. Sexual rest did not affect sperm motility. The predicted DSO varied with the equation used to determine TV. Clinically normal donkeys have high spermatogenic efficiency, which confirms previous histology reports.
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