Brilliant Cresyl Blue Research Articles

Electropolymerization of brilliant cresyl blue on carbon ionic liquid electrode and electrocatalytic application for the voltammetric determination of ascorbic acid

Brilliant cresyl blue (BCB) was electropolymerized on the surface of a carbon ionic liquid electrode (CILE) by cyclic voltammetric sweep in the potential range from -0.5 to 1.0 V. CILE was prepared by using 1-ethyl-3-methyl- imidazolium tetrafluoroborate ([EMIM]BF4) as modifier. The stable polymer film of BCB was obtained on the CILE and a pair of redox peaks appeared. The characteristics of PBCB film was studied by different methods such as scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry. This modified electrode showed excellent electrocatalytic response to ascorbic acid with the increase of the electrochemical responses. Under the optimal conditions a good linear voltammetric response could be obtained over the range of 2.0x10-5-3.0x10-3 mol L-1 and the detection limit was got as 6.5 µmol L-1 (3σ).

Zona pellucida glycoprotein 3 (pZP3) and integrin β2 (ITGB2) mRNA and protein expression in porcine oocytes after single and double exposure to brilliant cresyl blue test

Brilliant cresyl blues (BCB) staining test is a useful tool in assessing the competence of cumulus-oocyte-complexes (COCs) in several mammalian species. It is mostly used to select gametes after they are recovered from the ovary or before and after IVM to isolate those oocytes that reach developmental competency. However, there is evidence that double exposure to BCB test may lead to impaired fertilization or even have a toxic effect on cells. The aim of the present study was to investigate the expression pattern of sperm-egg interaction molecules in oocytes after single and double exposure to BCB test. Follicles were dissected from porcine ovaries after slaughter and aspirated COCs were cultured in standard porcine IVM culture medium (TCM 199) for 44 h. The BCB test was applied to COCs before and after IVM. In developmentally competent oocytes, assessed by determining the activity of glucose-6-phosphate dehydrogenase (G6PDH; BCB test), real-time quantitative PCR reaction methods, western blot and confocal microscopy analysis were applied to determine the transcript levels of porcine zona pellucida glycoprotein 3 (pZP3), and integrin beta 2 (ITGB2), as well as the levels of pZP3 and ITGB2 proteins. In the control group, assessment of the expression of the investigated genes was performed before and after IVM without BCB test. We observed a significantly higher level of pZP3 mRNA in oocytes after single exposure to BCB test compared to control before and after IVM (P < 0.001), and to double staining (P < 0.05). The level of ITGB2 mRNA was also increased in gametes after single exposure to BCB test as compared to control before and after IVM (P < 0.001, P < 0.01, respectively), and double staining (P < 0.05). Western blot analysis demonstrated a higher level of pZP3 protein in oocytes after single staining with BCB as compared to control both before and after IVM (P < 0.001, P < 0.05, respectively) and double staining (P < 0.05). Confocal microscopic observations have revealed the same pattern of increased level of pZP3 and ITGB2 expression after single exposure to BCB test. In both cases we detected specific cytoplasmic localization of both proteins. The ITGB2 protein has zona pellucida and membrane localization in control oocytes before IVM. After IVM and after single exposure to BCB, ITGB2 was also strongly detected in the cytoplasm. In both cases, after double exposure to BCB both proteins were detected only partially in the cytoplasm. Our results suggest that (i) single exposure to BCB increased the expression of sperm-oocyte interaction genes, (ii) double exposure to BCB leads to only partial expression of pZP3 and ITGB2 in oocyte cytoplasm, (iii) the BCB staining test itself may be a cause of specific pZP3 translocation from the zona pellucida to the cytoplasm, and that (iv) in vitro maturation of oocytes may increase ITGB2 expression and translocation from the zona pellucida to the cytoplasm.

Hydrogel nanocomposite sorbents for removal of basic dyes

Hydrogel nanocomposites having high amount of functional group, enhanced swelling ability, and improved mechanical properties were prepared for removal of basic dyes from aqueous solutions. Acrylamide (AAM) and itaconic acid sodium salt (IANa) were polymerized using polyethyleneglycol (400) diacrylate as crosslinker in the presence of montmorillonite (MMT). The products were characterized by swelling degree, total basic group content, XRD analysis, and FTIR spectroscopy. It was observed that MMT addition increased the itaconic acid gelation. The incorporation of low amount of MMT into the hydrogel structure increased also swelling degree. The products were used as adsorbent for removal of brilliant cresyl blue (BCB) from aqueous solutions. It was observed that the adsorption of BCB onto the nanocomposite completed in 30 min. It was found that the adsorption kinetics followed a pseudo-second-order kinetic model. Equilibrium isotherm of nanocomposite was analyzed using Freundlich and Langmuir isotherms. It was seen that the Langmuir isotherm model fit the adsorption data. These hydrogel nanocomposites have been shown to have the potential to be used as novel, fast-responsive and high capacity adsorbent materials for the removal of cationic dyes which is a serious problem, especially in textile industry.

A comparative study on the performance of photogalvanic cells with different photosensitizers for solar energy conversion and storage: D-Xylose-NaLS systems

The comparative performance of photogalvanic cells has been studied for solar energy conversion and storage by using Methyl Orange, Rose Bengal, Toluidine Blue and Brilliant Cresyl Blue as different photosensitizers with d-Xylose as reductant and Sodium Lauryl Sulphate (NaLS) as surfactant in the different systems. The photogeneration of photopotential are 890.0, 885.0, 945.0 and 940.0 mV whereas the maximum photocurrent is 625.0, 575.0, 510.0 and 480.0 μA, respectively. The short circuit current or photocurrent at equilibrium is 480.0, 460.0, 430.0 and 440.0 μA, respectively. The observed conversion efficiencies for Methyl Orange, Rose Bengal, Toluidine Blue and Brilliant Cresyl Blue with d-Xylose and Sodium Lauryl Sulphate systems are 1.6245, 1.5261, 1.4323 and 1.1057%, respectively. The fill factors 0.3244, 0.3151, 0.3120, and 0.2408 are experimentally determined at the power point of the cell where the absolute value is 1.0. The photogalvanic cells so developed can work for 160.0, 145.0, 130.0 and 140.0 min in dark if it is irradiated for 180.0, 165.0, 135.0 and 150.0 min, respectively where the percentage of storage capacity of photogalvanic cells are found 87.87%–96.29%. All observed results are the higher among the reported results so far in the literature.

Synthesis and EPR Studies of Copper Metal Complexes of Dyes Derived from Remazol Red B, Procino Yellow, Fast Green FCF, Brilliant Cresyl Blue with Copper Acetate Monohydrate

The synthesis and characterization of four new solid dye complexes, CuL2 (L= 2‐[2‐methoxy‐5‐(propane‐1‐sulfonyl)‐phenyl azo]‐naphthalen‐1‐ol, 5‐{[3‐(4,6‐dihydroxy‐[1,3,5]tri azine‐2‐ylamino)‐phenyl]‐hydrazones}‐1‐ethyl‐4‐methyl‐2,6‐dioxo‐1,2,5,6‐tetrahydro‐pyridine‐3‐carboxylic acid diethylamide, 4‐{bis‐[4‐(benzyl‐ethyl‐amino)‐phenyl]‐methyl}‐phenol and 7‐imino‐4‐methyl‐7H‐phenoxazine‐1,3‐diamine) is reported. The mode for ligand coordination has been determined by IR and EPR spectra. The carboxyl and amino group of dyes coordinates to the Cu(II) atom as a unidentate or as a chelating ligand.

Kinetic spectrophotometric determination of trace copper(II) ions by their catalytic effect on the reduction of brilliant cresyl blue by ascorbic acid

In the present study, a novel catalytic-kinetic spectrophotometric method was developed for the determination of trace amounts of copper. It is based on the catalytic effect of Cu(II) on the reduction of brilliant cresyl blue (BCB) by ascorbic acid in pH 5.0 acetate buffer medium. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of BCB at 624 nm. The operating conditions regarding concentration of reagents, pH, time, and temperature were established and optimized in detail. The working curve was linear in the concentration range of 0.1-5.0 \mu g L^{-1}. The maximum percentage error and standard deviation for 5 replicate determination of the 3 \mu g L^{-1} Cu(II) were 3.20 and 0.45, respectively. The detection limit and quantification limit were 0.025 and 0.086 \mu g L^{-1}, respectively. The procedure was successfully applied to determination of dissolved copper levels of 3 different natural spring waters and artificially prepared wastewater samples. The accuracy of the proposed kinetic method was tested by means of 5 replicate analyses of the certified standard materials, SRM 1640, based on 2 independent methods.

205 GLUCOSE-6-PHOSPHATE DEHYDROGENAZE ACTIVITY IN OVINE OOCYTES IS ASSOCIATED WITH PRE-IMPLANTATION EMBRYONIC DEVELOPMENT IN VITRO

A large proportion of ovine oocytes fail to develop into viable embryos following maturation, fertilization, and culture in vitro. Accurate, fast, and noninvasive predictors of ovine oocyte quality are therefore in urgent need for oocyte selection before in vitro maturation (IVM). Recent studies have shown that oocyte competence can be predicted through the presence of the glucose-6-phosphate dehydrogenase (G6PD) enzyme, as indicated by brilliant cresyl blue (BCB), a dye that can be degraded by G6PD. Thus, oocytes that have completed their growth phase show decreased G6PD activity and exhibit cytoplasm with a blue colouration (BCB+), whereas growing oocytes are expected to have a high level of G6PD, which results in colourless cytoplasm (BCB–). The brilliant cresyl blue staining test, as a noninvasive intrinsic criterion, has been successfully used to identify the more competent oocytes in various species. Therefore, this study aimed to investigate whether BCB staining, as an indicator of G6PD activity, can be used to select developmentally competent ovine oocytes before IVM and thereby increase the efficiency of in vitro embryo production. Ovine ovaries were obtained from a local slaughterhouse and transported to the laboratory, where cumulus–oocyte complexes (COC) were recovered by slicing the ovaries. Only oocytes with one or more complete layers of unexpanded cumulus cells and a homogeneous cytoplasm were used. The COC were exposed to 26 mM BCB diluted in modified Dulbecco’s PBS for 90 min at 39°C in humidified air. After BCB exposure, the COC were examined under a stereomicroscope and divided into 2 groups: BCB+ (blue cytoplasm, low G6PD activity) and BCB– (colourless cytoplasm, high G6PD activity). Cumulus–oocyte complexes in the control group were incubated for IVM directly after selection, without exposure to BCB dye. After IVM, oocytes were subjected to IVF followed by embryo culture for 7 days (5% CO2, 39°C, humidified air). Results were analysed by a chi-square test, and P &lt; 0.05 was considered statistically significant. The proportion of oocytes that cleaved by Day 2 after insemination was significantly (P &lt; 0.05) higher for the control and BCB+ groups [67.3% (68/101) and 71.7% (81/113), respectively] than for the BCB– group [50.5% (46/91)]. Significant differences among groups were also observed on Day 7 after fertilization, when the embryos reached the blastocyst stage of development. The BCB+ group yielded a significantly (P &lt; 0.05) higher proportion of blastocysts [34.5% (39/113)] than both the control [20.8% (21/101)] and BCB– [4.3% (4/93)] groups. In addition, the blastocyst rate of development in the control group was significantly (P &lt; 0.05) higher than that for the BCB– group. In conclusion, results of this study show that selection of ovine oocytes based on G6PD activity through the BCB test can be used as an efficient predictor of in vitro embryonic developmental competence. This positive predictive parameter of oocyte quality may also be useful in increasing the efficiency of blastocyst production during in vitro embryo production procedures in the ovine.

251 SELECTION OF PREPUBERTAL SHEEP OOCYTES USING BRILLIANT CRESYL BLUE TEST

The aim of this study was to evaluate the utility of the brilliant cresyl blue (BCB) test as an indirect measure of oocyte growth to select competent prepubertal sheep oocytes for in vitro embryo production. The BCB stain allows the determination of glucose–6-phosphate dehydrogenase (G6PD) activity, an enzyme with decreased activity in oocytes that have finished their growth phase. Oocytes were obtained after slicing the surface of lamb ovaries (2–5 months old) obtained from a local abattoir. Oocytes with more than 3 compact cumulus layers and homogeny cytoplasm were selected and stained with different concentrations of BCB diluted in PBS (13-, 26-, 39-, and 52-μM BCB) during 60 min at 38.5°C in a humidified air atmosphere. Oocytes were classified into groups depending on their cytoplasm coloration: oocytes with blue cytoplasm or grown oocytes (BCB+) and oocytes without blue coloration or growing oocytes (BCB–). Oocytes were matured in an enriched TCM-199 medium for 24 h at 38.5°C and 5% CO2 in a humidified atmosphere. Oocyte diameter was also measured. Matured oocytes were partially denuded and transferred to fertilization medium (SOF) supplemented with 10% of oestrous sheep serum. Fresh semen was kept at room temperature (25°C) for 1 h. Highly motile spermatozoa were selected by using Ovipure density gradient (Nidacon EVB S.L.), and oocytes were fertilized with 1 × 106 sp mL–1. After 20 h postinsemination, presumptive zygotes were cultured for 8 days in SOF with 10% of fetal bovine serum at 38.5°C, 5% CO2, and 90% N2. Data was analysed by performing Fisher’s exact test for blastocyst production and ANOVA with Tukey’s post-test for oocyte diameter. Table 1 shows the percentage of BCB-stained oocytes and their embryo development. In this study oocytes exposed during 60 min to 13-μM BCB showed a higher percentage of embryos reaching blastocyst stage than did those in the control group (≤0.01). In other species such as goats (Rodriguez-Gonzalez et al. 2002 Theriogenology 57(5), 1397–1409) and cattle (Alm et al. 2005 Theriogenology 63(8), 2194–2205), the best protocol for the oocyte selection was the use of 26-μM BCB during 90 min. Oocyte diameter showed significant differences between BCB– with BCB+ and control group (110 μm, 134 μm, and 121 μm, respectively, ≤0.001). In conclusion, using 13 μM of BCB during 60 min is a suitable technique for increasing embryo blastocyst rates using lamb oocytes. Table 1.Effect of BCB1 concentration on embryo development of lamb oocytes The grant sponsor was the Spanish Ministry of Science and Innovation, Code: AGL2007-60227-CO2-01.

Disturbances of nuclear maturation in BCB positive oocytes collected from peri-pubertal gilts

The developmental competence (quality) of oocytes is affected by several factors linked to their intrinsic properties and also to growth and maturation environment. Donor puberty and chromosomal complement are one of the main factors influencing oocyte quality. A high rate of porcine oocytes matured in vitro is chromosomally imbalanced. Moreover, there is no published data on chromosomal aberrations in oocytes selected by the brilliant cresyl blue (BCB) test. Therefore, the aim of this study was to analyze whether BCB positive (BCB+) oocytes derived from ovaries of peripubertal gilts (prepubertal NCL and cyclic CL) differ with respect to the incidence of numerical chromosome aberrations. COCs collected from NCL and CL ovaries were selected by the BCB test. Only BCB+ oocytes were matured in vitro and subjected to FISH analysis using molecular probes for chromosome pairs 1 and 10. The rate of BCB+ oocytes was similar for both groups of ovaries (NCL 80%, CL 92%). Altogether 554 oocytes were fixed and 471 oocytes at the MII stage were analyzed cytogenetically. Diploid (2MII) and aneuploid oocytes were detected. The contribution of MII oocytes was similar for NCL (85%) and CL (90%) group. Chromosomally aberrant BCB+ oocytes accounted for 18.0% and ranged from 13.7% for CL and 22.2% for NCL ovaries. Diploidy was a predominant anomaly observed (11.2%) with a significantly higher frequency in BCB+ oocytes of pre-pubertal (16.7%) than cyclic gilts (5.6%, P < 0.05). Aneuploid oocytes occurred with similar rate in NCL (6.7%) and CL (8.5%) females. The majority of aneuploid spreads (72.2%; P < 0.01) concerned the chromosome pair 10. The overall rate of disomy (56%) and nullisomy (44.4%) was similar. We have shown that donor puberty affects the incidence of chromosomal abnormalities in porcine oocytes matured in vitro. Significantly more diploid oocytes was derived from prepubertal ovaries, whereas the frequency of aneuploidy was similar in NCL and CL gilts.

46 THREE STAGES ESTABLISHMENT OF IN VITRO MATURATION OF PORCINE OOCYTES USED AS RECIPIENT CYTOPLASTS FOR SOMATIC CELL NUCLEAR TRANSFER

Oocytes at either anaphase/telophase of the first meiotic division (AI/TI) or metaphase of the second meiotic division (MII) are potential candidates used as recipient cytoplasts for somatic cell nuclear transfer (SCNT) because they contain active maturation-promoting factor (MPF), which causes nuclear membrane breakdown (NEBD) and premature chromosome condensation (PCC) in the transferred nucleus and may be essential for nuclear reprogramming (Campbell and Alberio 2003 Reprod. Suppl. 61, 477–494). In vitro maturation of porcine oocytes spends longer times (44 to 48 h), progresses asynchronously from immature stage and presents insufficient MPF for NEBD and PCC at AI/TI or MII. Here we have developed 3 stages establishment of in vitro oocyte maturation to select good quality of porcine oocytes used as recipient cytoplasts for SCNT. First, porcine oocytes were assessed by the activity of glucose-6-phosphate dehydrogenase (G6PD) before in vitro oocyte maturation. These oocytes with loss of expression of G6PD failed to enzymatically break down the dye, brilliant cresyl blue (BCB) and thus stain positively (Roca et al. 1998 Reprod. Fertil. Dev. 10, 479–485). Positively BCB stained oocytes reached to MII (67.0% v. 58.4%) and produced more parthenogenetic blastocysts (50.2% v. 29.6%) in comparison with negatively BCB stained oocytes (P &lt; 0.05). Second, positively BCB stained oocytes were treated with 5 μg mL–1 cycloheximide (CHXM, a nonspecific protein-synthesis inhibitor) to block meiotic progression for synchronizing the cell cycle of oocytes for 16 h. All of the oocytes (130/130) were efficiently synchronized at the germinal vesicle (GV) stage by treatment with CHXM, whereas control oocytes (w/o CHXM) were passed through GV stage (80/176). Retrieval from treatment of CHXM could reversibly induce meiotic resumption and progresses synchronously in porcine oocytes. Following incubation with gonadotropin hormones [epidermal growth factor (EGF) 10 ng mL–1, LH 5μg mL–1, FSH 1 μg mL–1], treatment with 5 mM caffeine (a phosphatase inhibitor) for 12 h significantly increased the activity of MPF in porcine oocytes (P &lt; 0.05). However, there was no difference between CHXM treated and nontreated group (21.9% v. 22.3%) in the developmental rate to the blastocyst stage of parthenogenetic embryos. At least 3 replicates were performed. These data may contribute to an improved nuclear reprogramming in SCNT.

Selection of Immature Bovine Oocytes Using Brilliant Cresyl Blue Enhances Nuclear Maturity after Vitrification

Beside cooling/warming rates and composition of vitrification solution, developmental stage of immature oocytes may also affect their vitrification outcome. The aim of the present study was to evaluate the selection effect of developmentally competent immature bovine oocytes by Brilliant Cresyl Blue (BCB) on maturity of oocytes after vitrification. Oocytes were obtained from slaughterhouse ovaries. Only oocytes with 4-5 layers of cumulus cells and homogenous cytoplasm were used. After exposure to BCB stain, immature oocytes were divided into colored (BCB+) and colorless (BCB-) cytoplasm groups. Immature oocytes were equilibrated in VS1 (7.5 Ethylene Glycol (EG)+7.5% DMSO) for 10-12 min and then exposed to VS2 (15% EG+ 15% DMSO+0.5M sucrose) for 1 min. Thereafter, oocytes were loaded on Cryotop and directly plunged into liquid nitrogen. After warming, oocytes were examined for presence of polar body and nuclear maturity. Higher number of oocytes in BCB+group extruded first polar body in comparison with other vitrified groups but not significantly (p>0.05). Compared to the BCB- oocytes, there was significantly lower percentage of degeneration for BCB+oocytes (p<0.05). Within vitrified groups, reaching to the MII stage was significantly higher in BCB+group (51.5%) compared with BCB and vitrified-control groups (27.9 and 40.3%, respectively). These results indicated that selection of potent immature bovine oocytes using brilliant cresyl blue improved the nuclear maturity of immature oocytes after vitrification. In addition, this selection can be a valuable tool to improve the vitrification outcome.

Assessment of transcript and protein levels contributing to cell cycle control and gap junction connections in morphologically variable groups of porcine cumulus-oocyte complexes

Oocytes and somatic cumulus cells are connected by an extensive network of gap junctions. These connections contribute in a major way to oocyte maturation and developmental competence. Cumulus-oocyte complexes (COCs) were cultured in standard porcine IVM culture medium (TCM 199) for 44 h. The morphological classification of COCs is based on the number of cumulus cell layers and the degree of their compaction, as well as on cytoplasm composition (homogenous, heterogeneous). The obtained COCs were divided into four grades according to this classification system. By assessing the activity of glucose-6-phosphate dehydrogenase (G6PDH) using the brilliant cresyl blue (BCB) test, real-time quantitative PCR (RQ-PCR) reaction methods and confocal microscopic observations, we determined the transcript levels of connexins 43 and 45, cyclin dependent kinases (cdk5 and cdk5r), and cdk inhibitors 1 and 3 (p27kip1 and cdkn3) as well as cdk4 protein in morphologically different groups of porcine oocytes isolated from puberal gilts. To assess their nuclear status the completely denuded oocytes were subjected to DAPI staining. We found statistically increased cdkn3, cdk5 and connexin 45 mRNA levels in oocytes graded as I as compared to II, III, and IV. The cdkn1, cdk5r and connexin 43 transcript contents were higher only when comparing between oocytes graded as I, III and IV. The cdk4 protein in oocytes graded I and II is localized mainly in the zona pellucida, although in grade III COCs the expression of this protein is decreased and observed only in the cytoplasm. Grade IV COCs do not demonstrate a significant presence of cdk4 protein. With regards to nuclear maturation, the percentage of MII stage oocytes was significantly (P &amp;lt; 0.05) higher in grade I and II oocytes as compared to grade III and IV oocytes. Our results demonstrate for the first time that cdk4 protein localization and all of the investigated transcript levels are associated with COC morphology and may be related to further maturation ability as well as developmental competence of oocytes.

Poly(brilliant cresyl blue) electrogenerated on single-walled carbon nanotubes modified electrode and its application in mediated biosensing system

Single-walled carbon nanotubes (SWCNTs) functionalized with carboxylic acid groups were cast to glassy carbon electrode (GCE) to construct a three-dimensional nano-micro structured scaffold. Brilliant cresyl blue (BCB) was electropolymerized on the above-mentioned SWCNTs/GCE using continuous cycling between −0.7 and 0.9 V vs. SCE. PolyBCB yielded on SWCNTs/GCE exhibited the enhanced electrochemical redox behavior compared with that electrogenerated on bare GCE. The apparent surface coverage of PolyBCB obtained by SWCNTs/GCE was at least 10 times higher than that obtained by bare GCE, namely 4.8 × 10 −9 and 3.6 × 10 −10 mol cm −2. The cyclic voltammograms recorded by PolyBCB/SWCNTs/GCE exhibited well-defined two peaks located at −0.25 V and −0.06 V, respectively, with a surface-controlled mechanism. In addition, morphologies of PolyBCB electrogenerated on GCE and SWCNTS/GCE were characterized by atomic force microscopy. Finally, this proposed PolyBCB/SWCNTs/GCE was used in the construction of the second-generation biosensors to hydrogen peroxide and glucose, with the enhanced analytical performance.

Removal of cationic dyes from aqueous solutions with poly (N-isopropylacrylamide-co-itaconic acid) hydrogels

In this study, N-isopropylacrylamide-based temperature and pH-sensitive hydrogels were synthesized by free radical polymerization for removal of cationic dyes from aqueous solutions. For this purpose, N-isopropylacrylamide was copolymerized with various amounts of sodium salt of itaconic acid in the presence of crosslinking agent (N,N-methylene bisacrylamide). The chemical structures of hydrogels were characterized by FT-IR analysis. In order to investigate swelling properties of the hydrogels, water absorption (swelling) and shrinking (deswelling) kinetics, the equilibrium swelling ratios in water and different pH buffer solutions, and the temperature dependent swelling ratios were determined. Then, their adsorption properties such as adsorption capacities, kinetics, isotherms were investigated in case of their usage in removal of Safranine T (ST), Brilliant Green (BG), and Brilliant Cresyl Blue (BCB) aqueous solutions. According to adsorbed dye amount, the adsorption capacities are followed the order BG > ST ≅ BCB. In addition, the results indicated that the pseudo-second-order kinetic model fitted better than the data obtained from pseudo-first-order model for the adsorption of all dyes onto hydrogels. Furthermore, according to effect of the initial dye concentration findings, it is concluded that, Freundlich isotherm explains the adsorption better than Langmuir isotherm.

Modified maghemite nanoparticles as an efficient adsorbent for removing some cationic dyes from aqueous solution

A novel adsorbent, sodium dodecyl sulfate (SDS) modified maghemite nanoparticles (SDS–γ-Fe 2O 3), was used for removal of cationic dyes brilliant cresyl blue (BCB), thionine (Th) and janus green b (JG), from water samples. Prepared nanoparticles were characterized by TEM, SEM, XRD, BET and EDX measurements. The influences including initial pH, dosage of adsorbent, surfactant amount and contact time have been researched in order to find the optimum adsorption conditions. The experimental data were analyzed by the Langmuir and Freundlich adsorption models. Equilibrium data fitted very well with the Langmuir model signifying the energetic homogeneity of SDS-maghemite surface adsorption sites. The maximum predicted adsorption capacities for Th, BCB and JG dyes were obtained as 200.0, 166.7 and 172.4 mg g − 1 , respectively. It was shown that the sorbent can remove more than 93% of the investigated dyes within the first 4 min of contact time. The desorption process of the adsorbed cationic dyes was also investigated using methanol and methanol–acetic acid mixture as the solvent. It was notable that both the adsorption and desorption of dyes were quite fast probably due to the absence of internal diffusion resistance.

Advances in Swine In Vitro Embryo Production Technologies

Recent advances in new technologies to produce cloned and genetically modified pigs involve manipulating oocytes and/or embryos in vitro. Although a great deal of progress has been made, the current IVM-IVF systems still result in major problems: a high rate of polyspermy; and a low development rate and low quality of blastocysts for in vitro compared with the in vivo-produced embryos. This study summarizes recent advancements in IVM-IVF-IVC porcine systems. Recent methods to select monospermic embryos are also discussed. Finally, achievements in vitrification and in somatic cell nuclear transfer are discussed.

Removal of basic dyes from aqueous solutions by dimethyl terephthalate distillation residue

In this study the removal of basic dyes from aqueous solutions by residue acid mixture (RAM) obtained from dimethyl terephthalate distillation residue was investigated. Adsorption experiments were carried out at ambient temperature. A fixed amount of sample was immersed in 50 mL basic dye (500 mg/L) solutions. The amount of residual dye concentrations was determined using UV/Vis Spectrophotometer at wavelength 530 nm Safranine-T (ST), 622 nm Brilliant Cresyl Blue (BCB), 638 nm Nile Blue (NB) and 618 nm Brilliant Green (BG). Adsorption capacities of RAM for basic dyes decrease with the following order: BG > ST > NB > BCB. The maximum adsorption capacities for BG, NB, ST and BCB onto RAM were found to be 107, 22, 17, 13 mg/g, respectively. Adsorption kinetic data were tested using pseudo-first-order and pseudo-second-order models. The results show that the pseudo-second-order kinetic model fitted better than the data obtained from pseudo-first-order model for the adsorption of basic dyes onto RAM. Adsorption data were modeled using Langmuir and Freundlich adsorption isotherms. The result revealed that the adsorption of basic dyes onto RAM fit very well with the Langmuir isotherm model.

Trace Molecular Detection via Surface-Enhanced Raman Scattering and Surface-Enhanced Resonance Raman Scattering at a Distance of 15 Meters

We report the first demonstration of surface-enhanced Raman spectroscopy (SERS) detection of para-mercapto benzoic acid (pMBA) and surface-enhanced resonance Raman spectroscopy (SERRS) detection of brilliant cresyl blue (BCB) and cresyl violet perchlorate (CVP) with continuous-wave excitation from a stand-off distance of 15 meters. We further report the first stand-off SERRS detection of BCB and CVP at that same distance in the presence of ambient fluorescent and incandescent/blackbody background light. These preliminary results suggest that it is possible to detect sub-nanomole amounts of material at reasonable distances with eye-safe laser powers using stand-off SERRS and serve as proof-of-concept highlighting the potential extension of stand-off Raman spectroscopy to include SERS and SERRS for remote, eye-safe chemical detection, analysis, and imaging in the presence of ambient background light.

Study on the performance of photogalvanic cells for solar energy conversion and storage: Brilliant Cresyl Blue—D-Xylose—Sodium Lauryl Sulphate system

SYNOPSIS The performance of photogalvanic cells for solar energy conversion and storage has been studied in a previously unexplored photogalvanic system containing Brilliant Cresyl Blue as photosensitiser with D-Xylose as reductant and Sodium Lauryl Sulphate (NaLS) as surfactant. The observed value of the photogeneration of photopotential was 940.0 mV and photocurrent was 440.0 μA. The maximum power of the cell was 413.16 μW whereas the observed power at the power point was 115.00 μW. The conversion efficiency was 1.1057%. A fill factor of 0.2408 was experimentally determined at the power point of the photogalvanic cell. The rate of initial generation of current is 53.33 μA min-1. The photogalvanic cell so developed can work for 140.0 minutes in the dark if it is irradiated for 150.0 minutes, i.e. the storage capacity of the photogalvanic cell is 93.33%. Performance values exceed those reported in previous works.

A highly selective optical sensor for catalytic determination of ultra-trace amounts of nitrite in water and foods based on brilliant cresyl blue as a sensing reagent

A new optical sensor has been developed for nitrite determination based on the use of brilliant cresyl blue (BCB) immobilized on triacetyl cellulose membrane using absorption spectrophotometry. The sensor is based on the reaction of BCB with bromate as an oxidant in the presence of nitrite in acidic media to produce a colorless product. Nitrite has a strong catalytic effect on the reaction of BCB with bromate. The difference in the absorbance of the optode at 570 nm between uncatalyzed and catalyzed reactions (Δ A) was found to be directly proportional to the concentration of nitrite. A detection limit was found to be 1.76 nmol L −1 (0.08 ng mL −1). The corresponding detection limit of 1.9 nmol L −1 is well below the maximum admissible concentration level of 2.2 μmol L −1 required by the European Community. The sensor response from different probes ( n = 8) gave an RSD% of 2.4% at 2.17 μmol L −1 nitrite concentration. The proposed sensor was successfully applied for the determination of nitrite in water and food samples.