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Publication
Journal: Dalton Transactions
October/23/2014
Abstract
The isolation of six isomeric, low-symmetry, dicobaltacarboranes with bicapped hexagonal antiprismatic cage structures, always in low yield, is described from reactions in which 13-vertex cobaltacarborane anions and sources of cobalt-containing cations were present. The vertex-to-centroid distance (VCD) and boron-H distance (BHD) methods are used to locate the correct C atom positions in the cages, thus allowing the compounds to be identified as 1,13-Cp2-1,13,2,10-closo-Co2C2B10H12 (1), 1,8-Cp2-3-OEt-1,8,2,10-closo-Co2C2B10H11 (2), 1,13-Cp2-1,13,2,9-closo-Co2C2B10H12 (3), 1,8-Cp2-1,8,2,4-closo-Co2C2B10H12 (4), 1,13-Cp2-1,13,2,4-closo-Co2C2B10H12 (5) and 1,8-Cp2-1,8,2,5-closo-Co2C2B10H12 (6). It is shown that a common alternative method of cage C atom identification, using refined (as B) U(eq) values, does not work well, at least in these cases. Having identified the correct isomeric forms of the six dicobaltacarboranes, their syntheses are tentatively rationalised in terms of the direct electrophilic insertion of a {CpCo(+)} fragment into [CpCoC2B10](-) anions and it is demonstrated that compounds 1, 4, 5 and 6 can be successfully prepared by deliberately performing such reactions.
Publication
Journal: Zhonghua fu chan ke za zhi
October/9/2008
Abstract
OBJECTIVE
To evaluate the diagnostic and prognostic value of serum CA19-9, CA125 and CP2 in mucinous ovarian tumors.
METHODS
In this retrospective study, the serum CA19-9, CA125 and CP2 levels of 273 hospitalized patients with ovarian tumors of either mucinous or non-mucinous type were analyzed.
RESULTS
(1) CA19-9 had the biggest area under curve (AUC) in mucinous tumors followed with CA125 while CA125 and CP2 had bigger AUC in non-mucinous tumor. (2) For the diagnosis of mucinous tumors, CA19-9 and CA125 combination showed a greatly increased sensitivity compared with CA19-9 or CA125 alone (93.8% versus 75.0% and 66.7%, P<0.05) with no significant improvement of the specificity (P>0.05). For the diagnosis of non-mucinous tumors, CA125 and CP2 combination showed an increased sensitivity compared with CA125 or CP2 alone (85.0% versus 80.7%, P>0.05, 85.0% versus 70.6%, P<0.05) with no significant improvement of the specificity (P>0.05). (3) Seventy percent of tumor marker-positive patients could undergo cytoreductive surgery. Compared with those who could not undergo cytoreductive surgery, they were more likely to have normal tumor marker two months after surgery (P<0.05) and longer interval to re-elevation of tumor markers (P>0.05), with lower recurrence and death rate (P<0.05). All of the 20 tumor marker-negative patients could have cytoreductive surgery with only 10% recurrence. (4) CA19-9 increased mainly in recurrent mucinous tumor, while CA125 increased dominantly in recurrent non-mucinous tumor. (5) The survival rate of CA125 and CP2 positive patients was much lower than CA125 and CP2 negative patients (P<0.05), while the survival rate was similar between CA19-9 positive and CA19-9 negative patients.
CONCLUSIONS
CA19-9 is a sensitive index for diagnosis of mucinous ovarian tumors. Combination of CA19-9 with CA125 can improve the sensitivity of diagnosis and postoperative monitoring of mucinous ovarian tumors. Combination of CA125 with CP2 is more valuable in the diagnosis of non-mucinous ovarian tumors.
Publication
Journal: Biochimica et Biophysica Acta - General Subjects
March/12/1979
Abstract
The catalytically inactive complex generated by the combination of the Azotobacter vinelandii MoFe protein (Av1) and the Clostridium pasteurianum Fe protein (Cp2) inhibits N2 reduction, C2H3 reduction, H+ reduction and ATP hydrolysis catalyzed by the homologous nitrogenases. Kinetic data indicate that the inactive complex consists of two molecules of Cp2 to one molecule of Av1, with values for the inhibitor constant in the range of 1--10 nM. Inhibition of C. pasteurianum nitrogenase by Av1 produces a lag phase in acetylene reduction that increases with increasing Av1. The lag phase is found only at levels of Av1 sufficient to keep the ratio of Cp2 : Cp1 lower than 2. Gel filtration of a mixture of Av1 and Cp2 provides evidence for complex formation and indicates that each Av1 molecule binds more than one Cp2 molecule. The Av1-Cp2 complex binds two molecules of MgATP per molecule of Cp2. MgATP is not required for complex formation, but complex formation lowers the MgATP-Cp2 dissociation constant approx. 3-fold. Av1 protects the iron-sulfur center in Cp2 completely against the MgATP-induced reaction with chelators. This provides additional evidence for formation of the Av1-Cp2 complex and together with the results of the MgATP-binding studies suggests that the two binding sites for MgATP are some distance away from the iron-sulfur site on Cp2.
Publication
Journal: International Journal of Biological Macromolecules
July/7/1992
Abstract
The two-domain structure of streptokinase (Sk) was demonstrated by scanning calorimetric investigations at neutral pH and low ionic strength. The melting pattern of the protein is composed of two two-state transitions at TtrS1 = 45.9 +/- 0.4 degrees C with delta H1 = 431 +/- 18 kJ/mol, and TtrS2 = 60.1 +/- 1.3 degrees C with delta H2 = 306 +/- 16 kJ/mol. The partial specific heat capacity of native Sk was determined to be Cp = 1.42 +/- 0.17 J/K/g and the denaturational heat capacity change associated with the two transitions, delta Cp1 = 0.21 J/K/g and delta Cp2 = 0.38 J/K/g, respectively. The overall melting pattern of Sk remains almost unchanged at a variety of tested solvent compositions, except at pH 4 (and below) and in the presence of denaturants. The two domains show different susceptibility to urea. It is proposed that the less thermostable domain is located within the N-terminal part (residues 1-230), and the more thermostable one, within the C-terminal region.
Publication
Journal: Biochimica et Biophysica Acta - General Subjects
January/17/2001
Abstract
Steady state kinetic measurements are reported for nitrogenase from Azotobacter vinelandii (Av) and Clostridium pasteurianum (Cp) under a variety of conditions, using dithionite as reductant. The specific activities of Av1 and Cp1 are determined as functions of Av2:Av1 and Cp2:Cp1, respectively, at component protein ratios from 0.4 to 50, and conform to a simple hyperbolic rate law for the interaction of Av2 with Av1 and Cp2 with Cp1. The specific activities of Av2 and Cp2 are also measured as a function of increasing Av1 and Cp1 concentrations, producing 'MoFe inhibition' at large MoFe:Fe ratios. When the rate of product formation under MoFe inhibited conditions is re-plotted as increasing Av2:Av1 or Cp2:Cp1 ratios, sigmoidal kinetic behavior is observed, suggesting that the rate constants in the Thorneley and Lowe (T&L) model are more dependent upon the oxidation level of MoFe protein than previously suspected [R.N.F. Thorneley, D.J. Lowe, Biochem. J. 224 (1984) 887-894], at least when applied to Av and Cp. Calculation of Hill coefficients gave values of 1.7-1.9, suggesting a highly cooperative Fe-MoFe protein interaction in both Av and Cp nitrogenase catalysis. The T&L model lacks analytical solutions [R.N.F. Thorneley, D.J. Lowe, Biochem. J. 215 (1983) 393-404], so the ease of its application to experimental data is limited. To facilitate the study of steady state kinetic data for H(2) evolution, analytical equations are derived from a different mechanism for nitrogenase activity, similar to that of Bergersen and Turner [Biochem. J. 131 (1973) 61-75]. This alternative cooperative model assumes that two Fe proteins interact with one MoFe protein active site. The derived rate laws for this mechanism were fitted to the observed sigmoidal behavior for low Fe:MoFe ratios (<0.4), as well as to the commonly observed hyperbolic behavior for high values of Fe:MoFe for both Av and Cp.
Publication
Journal: Graefe's Archive for Clinical and Experimental Ophthalmology
August/29/2010
Abstract
BACKGROUND
To evaluate the efficacy and safety of heavy silicone oil Oxane Hd as intraocular tamponade in the treatment of complicated retinal detachment (RD).
METHODS
Forty eyes of 40 patients with complicated RD were recruited for this prospective study. Inclusion criteria were proliferative vitreoretinopathy grade>> or = CP2, mainly inferior and posterior retinal breaks, or superior retinal breaks with patient's inability to posture. Oxane Hd was used as intraocular tamponade. The retinal status, the best-corrected visual acuity (BCVA) results, and any complications were observed.
RESULTS
The mean duration of Oxane Hd endotamponade was 87.9 +/- 10.4 days, and the mean follow-up time after Oxane Hd removal was 438.1 +/- 153.7 days. The primary anatomical success rate after Oxane Hd removal was 87.5%, and with further intervention 97.5%. The BCVA significantly improved, from mean logMAR 2.12 +/- 0.60 to 1.38 +/- 0.59 (P < 0.001). The postoperative complications included temporary inflammatory reaction, moderately high intraocular pressure, heavy silicone oil emulsification, lens opacity and retinal proliferative membranes.
CONCLUSIONS
Without a requirement for postoperative prone position, heavy silicone oil Oxane Hd is effective and safe for the treatment of complicated RD with inferior and posterior breaks. Larger groups and a longer follow-up period will be included to further evaluate the efficacy with Oxane Hd in superior retinal breaks.
Publication
Journal: Biochemistry
July/14/1996
Abstract
We report the purification and characterization of a novel neuropeptide from Aplysia nervous tissue. The peptide was termed cerebral peptide 2 (CP2) because it was the larger of two peptides predominantly synthesized in the cerebral ganglia and transported to other regions of the central nervous system. The purification of CP2 from extracts of cerebral ganglia using three sequential modes of high-pressure liquid chromatography (HPLC) was followed using the [35S]methionine-labeled peptide obtained from transport experiments. The primary structure of CP2 was determined by automated Edman degradation of native CP2 and its proteolytic fragments in conjunction with mass spectrometry. CP2 is a 41 amino acid peptide with an amidated carboxyl terminal. A peptide with the proposed sequence of CP2 was synthetized and compared by HPLC with the native peptide. Chromatographic properties of the synthetic and native peptide labeled in vivo were found to be identical. CP2 does not appear to be a member of any previously identified peptide family.
Publication
Journal: Inorganic Chemistry
May/30/2007
Abstract
Water-soluble pi-conjugated polymers (CPs) incorporating 5,5'-(2,2'-dipyridyl) (CP1) or 6,6'-(2,2'-dipyridyl) (CP2) units within the pi-conjugated backbone were prepared as scaffolds for macromolecular metal complexation. The response of CP emission to a range of metal ions was investigated in water, 10 mM aqueous sodium dodecyl sulfate, and acetonitrile/water (95:5). Cupric ions are the most efficient quenchers of CP emission, with K(SV) = 1.1 x 10(5) and 5.2 x 10(4) M(-1) in water for CP1a (40% bipyridyl monomer units) and CP1b (20% bipyridyl monomer units), respectively. Quenching is approximately twice as effective in acetonitrile/water (95:5) (K(SV) = 3.1 x 10(5) M(-1) for CP1a and 1.1 x 10(5) M(-1) for CP1b). Partial restoration of emission was observed upon exposure of Cu(II)-CP solutions to excess NO(g) in acetonitrile/water (95:5) or 10 mM SDS(aq).
Publication
Journal: Biochimica et Biophysica Acta - General Subjects
October/19/1976
Abstract
Various photochemical activities were tested on chloroplasts of Zea mays that received 4 s of light every 4 h during the culture period. Photosystem I and Photosystem II were functioning, as well as the photosynthetic electron transport. These chloroplasts exhibited upon sodium dodecyl sulphate gel electrophoresis neither Complex 1 (Mr 70 000) generally associated with Photosystem I nor Complex 2 Mr 25 000) generally associated with Photosystem II. Chlorophyll is indeed attached to polypeptides of molecular weight 21 000 and 29 000. These results lead us to question the functional role of chloroplast protein-pigment complexes observed by sodium dodecyl sulphate gel electrophoresis.
Publication
Journal: Biology of Reproduction
September/30/1992
Abstract
The objectives of this study were to identify and characterize dog uterine endometrial proteins synthesized de novo in explant culture during early luteal phase, to examine distribution of these proteins prior to the embryo's entering the uterus and during its free-floating period prior to implantation, and to examine regulation of endometrial proteins by estrogen and progesterone (P4) treatments. Uterine endometrium was collected from cyclic and pregnant bitches on diestrus Days 3, 7, and 10 as determined by loss of cornification of vaginal epithelium, and from ovariectomized dogs after treatment with corn oil, estrogen, P4, or estrogen followed by 1 or 2 wk of P4. Tissue was incubated in an explant culture system in the presence of [3H]leucine or [35S]methionine. The rate of incorporation of [3H]leucine into nondialyzable macromolecules indicated no significant change in rates of incorporation by status (pregnant vs. nonpregnant), day, or steroid treatment. Uterine endometrial-conditioned culture medium, analyzed by two-dimensional SDS-PAGE and fluorography, revealed a complex array of at least ten proteins or protein complexes in cyclic and pregnant bitches. No difference in protein pattern was detected by status; however, differences in distribution were apparent by day of cycle or early pregnancy. Two major proteins, cP5 (M(r) 54,686) and cP6 (M(r) 23,010) appeared to be differentially expressed. Expression of cP5, maximal on diestrus Day 3, decreased as the cycle or pregnancy progressed to diestrus Day 10. In contrast, expression of cP6, a minor protein on diestrus Day 3, appeared to be up-regulated for each status to Day 10, with increased intensity and multiple isoelectric and molecular-weight variants. In ovariectomized steroid-treated dogs, two-dimensional SDS-PAGE showed that pattern and distribution of specific proteins were affected by treatment. Acidic protein cP1 (M(r) 87,600), synthesized after corn oil and P4 treatment, was suppressed with estradiol (E2). Proteins cP2 (M(r) 40,000 and M(r) 42,000), present with all treatments, were intensified with P4. A high-M(r) basic protein complex (cP3) and acidic protein cP4 were expressed with E2 and maintained with P4 treatment. Proteins cP5 and cP6, while not induced by E2 or P4 alone, required E2 priming for P4 induction. Protein cP5 was down-regulated while cP6 was up-regulated with P4 for 2 wk. Proteins induced by estrogen followed by 1 or 2 wk of P4 treatments were similar to those released by endometrial explants collected from pregnant and cyclic bitches on Days 3, 7, and 10 of spontaneous diestrus.(ABSTRACT TRUNCATED AT 400 WORDS)
Publication
Journal: Infection, Genetics and Evolution
November/20/2014
Abstract
Trypanosoma congolense is the most important agent of nagana, a wasting livestock trypanosomosis in sub-Saharan Africa. This species is a complex of three subgroups (Savannah, Forest and Kilifi) that differ in virulence, pathogenicity, drug resistance, vectors, and geographical distribution. Congopain, the major Cathepsin L-like cysteine protease (CP2) of T. congolense, has been extensively investigated as a pathogenic factor and target for drugs and vaccines, but knowledge about this enzyme is mostly restricted to the reference strain IL3000, which belongs to the Savannah subgroup. In this work we compared sequences of congopain genes from IL3000 genome database and isolates of the three subgroups of T. congolense. Results demonstrated that the congopain genes diverged into three subclades consistent with the three subgroups within T. congolense. Laboratory and field isolates of Savannah exhibited a highly polymorphic repertoire both inter- and intra-isolates: sequences sharing the archetypical catalytic triad clustered into SAV1-SAV3 groups, whereas polymorphic sequences that, in general, exhibited unusual catalytic triad (variants) assigned to SAV4 or not assigned to any group. Congopain homologous genes from Forest and Kilifi isolates showed, respectively, moderate and limited diversity. In the phylogenetic tree based on congopain and homologues, Savannah was closer to Forest than to Kilifi. All T. congolense subgroup nested into a single clade, which together with the sister clade formed by homologues from Trypanosoma simiae and Trypanosoma godfreyi formed a clade supporting the subgenus Nannomonas. A single PCR targeting congopain sequences was developed for the diagnosis of T. congolense isolates of the three subgroups. Our findings demonstrated that congopain genes are valuable targets for the diagnosis, genotyping, and phylogenetic and taxonomic inferences among T. congolense isolates and other members of the subgenus Nannomonas.
Publication
Journal: FEBS Letters
February/11/2003
Abstract
The activation domain of class I aminoacyl-tRNA synthetases, which contains the Rossmann fold and the signature sequences HIGH and KMSKS, is generally split into two halves by the connective peptides (CP1, CP2) whose amino acid sequences are idiosyncratic. CP1 has been shown to participate in the binding of tRNA as well as the editing of the reaction intermediate aminoacyl-AMP or the aminoacyl-tRNA. No function has been assigned to CP2. The amino acid sequence of Acidithiobacillus ferrooxidans TrpRS was predicted from the genome sequence. Protein sequence alignments revealed that A. ferrooxidans TrpRS contains a 70 amino acids long CP2 that is not found in any other bacterial TrpRS. However, a CP2 in the same relative position was found in the predicted sequence of several archaeal TrpRSs. A. ferrooxidans TrpRS is functional in vivo in Escherichia coli. A deletion mutant of A. ferrooxidans trpS lacking the coding region of CP2 was constructed. The in vivo activity of the mutant TrpRS in E. coli, as well as the kinetic parameters of the in vitro activation of tryptophan by ATP, were not altered by the deletion. However, the K(m) value for tRNA was seven-fold higher upon deletion, reducing the efficiency of aminoacylation. Structural modeling suggests that CP2 binds to the inner corner of the L shape of tRNA.
Publication
Journal: Journal of Biological Chemistry
August/1/2019
Abstract
Understanding the mechanism of how liver ductal cells (cholangiocytes) differentiate into hepatocytes would permit liver-regenerative medicine. Emerging liver ductal organoids provide an ex vivo system to investigate cholangiocyte-to-hepatocyte differentiation. However, as current gene manipulation methods require organoid dissociation into single cells and have only low efficiency, it is difficult to dissect specific gene functions in these organoids. Here we developed the adeno-associated virus (AAV) vector AAV-DJ as a powerful tool to transduce mouse and human liver ductal organoids. Via AAV-DJ-mediated up- or down-regulation of target genes, we successfully manipulated cholangiocyte-to-hepatocyte differentiation. We induced differentiation by overexpressing the hepatocyte-specifying regulator hepatocyte nuclear factor 4α (HNF4α) and blocked differentiation by stimulating Notch signaling or interfering with Smad signaling. Further screening for transcriptional factors critical for cholangiocyte-to-hepatocyte differentiation identified HOP homeobox (HOPX), T-box 15 (TBX15), and transcription factor CP2-like 1 (TFCP2L1) as master regulators. We conclude that this highly efficient and convenient gene manipulation system we developed could facilitate investigation into genes involved in cell lineage transitions and enable application of engineered organoids in regenerative medicine.
Publication
Journal: Phytomedicine
January/22/2019
Abstract
Cisplatin (CP) is a chemotherapeutic drug for treating melanoma that also causes adverse side effects in cancer patients.This study investigated the bioefficacy of a phytoagent deoxyelephantopin (DET) in inhibiting B16 melanoma cell activity, its synergism with CP against metastatic melanoma, and its capability to attenuate CP side effects in animals.DET and CP bioactivities were assessed by MTT assay, isobologram analysis, time-lapse microscopy, migration and invasion assays, flow cytometry and western blotting. In vivo bioluminescence imaging was used to detect lung metastasis of B16 cells carrying COX-2 reporter gene in syngeneic mice. H&E staining and immunohistochemistry were used to evaluate the compound/drug efficacy and CP side effects. Nephrotoxicity caused by CP treatment in mice was evaluated by UPLC/ESI-QTOF MS - based metabolomics and haematometry.

RESULT
DET, alone or in combination with cisplatin, inhibited B16 cell proliferation, migration, and invasion, and induced cell-cycle arrested at the G2/M phase and de-regulated cell-cycle mediators in cancer cells. In a murine B16COX-Luc metastatic allograft model, CP2 (2 mg/kg) treatment inhibited B16 lung metastasis accompanied by severe body weight loss, renal damage and inflammation, and haematological toxicity. DET10 and CP cotreatment (DET10 + CP1) or sequential treatment (CP2→DET10) significantly inhibited formation of pulmonary melanoma foci and reduced renal damage. DET pretreatment (Pre-DET10) or CP2→DET10 treatment had the longest survival (52 vs. 37 days for tumor control mice). CP treatment caused abnormally accumulated urea cycle metabolites and serotonin metabolite hippuric acid in renal tissues that were not seen with DET alone or in combination with CP.

The CP and DET combination may be an effective intervention for melanoma with reduced side effects.
Publication
Journal: Zoonoses and Public Health
April/4/2007
Abstract
Qualitative and quantitative contamination of ready-to-eat food-stuffs with the pathogen Listeria monocytogenes was studied in 1586 samples collected from 103 supermarkets (n = 946) and 61 households (n = 640) in Vienna, Austria. Seventeen groups of ready-to-eat foods were classified into three risk categories for contamination (CP1-CP3). Three to four samples were randomly collected at the retail level from each CP. Regarding the households, the sampling procedure was started with food items of CP1, and if not available, was continued with sampling of food items of CP2 and finally of CP3. Additionally, 184 environmental samples (swabs from the kitchen area, dust samples from the vacuum cleaner) and faecal samples (household members and pet animals) were included. One-hundred and twenty-four (13.1%) and 45 (4.8%) samples out of 946 food samples collected from food retailers tested positive for Listeria spp. and L. monocytogenes, respectively, with five smoked fish samples exceeding the tolerated limit of 100 CFU/g food. Food-stuffs associated with the highest risk of contamination were twice as frequently contaminated with L. monocytogenes as food-stuffs associated with a medium risk of contamination. Products showing the highest contamination rate were fish and seafood (19.4%), followed by raw meat sausages (6.3%), soft cheese (5.5%) and cooked meat products/patés (4.5%). The overall contamination rate of foods collected at the household level was more than two times lower. Only 5.6% and 1.7% of 640 food-stuffs analysed tested positive for Listeria spp. and L. monocytogenes, respectively. However, CP1 foods were rarely collected. Pulsed-field gel electrophoresis (PFGE) typing of the collected L. monocytogenes isolates revealed a high degree of diversity between the isolates, with some exceptions. PFGE typing of isolates harvested from green-veined cheese revealed a match among strains, although the manufacturer seemed to be distinguishable. Typing of household strains revealed an epidemiological link within one family. In this case, food-stuffs and the kitchen environment were contaminated by an indistinguishable isolate. In addition, the same isolate was collected from a pooled faecal sample of the household members suggesting that consumption of even low contaminated food items (<100 CFU/g) results in Listeria shedding after the passage through the gut.
Publication
Journal: Acta Pharmacologica Sinica
June/27/2017
Abstract
Acetylthevetin B (ATB), a cardiac glycoside from the seed of Thevetia peruviana (Pers) K Schum (yellow oleander), exhibits not only antitumor activity but also potential cardiac toxicity. In the present study, we attempted to enhance its antitumor action and decrease its adverse effects via chitosan-Pluronic P123 (CP) micelle encapsulation. Two ATB-loaded CP micelles (ATB-CP1, ATB-CP2) were prepared using an emulsion/solvent evaporation technique. They were spherical in shape with a particle size of 40-50 nm, showed a neutral zeta potential, and had acceptable encapsulation efficiency (>90%). Compared to the free ATB (IC50=2.94 μmol/L), ATB-loaded CP micelles exerted much stronger cytotoxicity against human lung cancer A549 cells with lower IC50 values (0.76 and 1.44 μmol/L for ATB-CP1 and ATB-CP2, respectively). After administration of a single dose in mice, the accumulation of ATB-loaded CP1 micelles in the tumor and lungs, respectively, was 15.31-fold and 9.49-fold as high as that of free ATB. A549 xenograft tumor mice treated with ATB-loaded CP1 micelles for 21 d showed the smallest tumor volume (one-fourth of that in the control group) and the highest inhibition rate (85.6%) among all the treatment groups. After 21-d treatment, no significant pathological changes were observed in hearts and other main tissues. In summary, ATB may serve as a promising antitumor chemotherapeutic agent for lung cancer, and its antitumor efficacy was significantly improved by CP micelles, with lower adverse effects.
Publication
Journal: Theriogenology
September/2/2010
Abstract
Three experiments were conducted to evaluate the impact of centrifugation on cooled and frozen preservation of equine semen. A standard centrifugation protocol (600 x g for 10 min=CP1) was compared to four protocols with increasing g-force and decreased time period (600 x g, 1200 x g, 1800 x g and 2400 x g for 5 min for CP2, 3, 4, and 5, respectively) and to an uncentrifuged negative control. In experiment 1, the influence of the different CPs on sperm loss was evaluated by calculating the total number of sperm cells in 90% of the supernatant. Moreover, the effect on semen quality following centrifugation was assessed by monitoring several sperm parameters (membrane integrity using SYBR14-PI, acrosomal status using PSA-FITC, percentage total motility (TM), percentage progressive motility (PM) and beat cross frequency (BCF) obtained with computer assisted sperm analysis (CASA)) immediately after centrifugation and daily during chilled storage for 3 d. The use of CP1 resulted in a sperm loss of 22%. Increasing the centrifugation force to 1800 x g and 2400 x g for 5 min led to significantly lower sperm losses (7.4% and 2.1%, respectively; P<0.05). Compared to the uncentrifuged samples, centrifugation of semen resulted in a better sperm quality after chilled storage. There were minimal differences between the CPs although total motility was lower for CP2 than for the other treatments (P<0.005). In experiment 2, the centrifuged samples were cryopreserved using a standard freezing protocol and analyzed immediately upon thawing. Samples centrifuged according to CP2 resulted in a higher BCF (P<0.005), whereas CP3 and CP5 yielded a lower BCF (P<0.05) when compared to CP1. There were no post thaw differences between CP1 and CP4. In experiment 3, DNA integrity of the different samples was analyzed using TUNEL. Although DNA integrity decreased over time, CP had no impact. In conclusion, the loss of sperm cells in the supernatant after centrifugation can be substantially reduced by increasing the g-force up to 1800 x g or 2400 x g for a shorter period of time (5 min) compared to the standard protocol without apparent changes in semen quality, resulting in a considerable increase in the number of insemination doses per ejaculate.
Publication
Journal: Biosensors and Bioelectronics
September/9/2018
Abstract
In this paper, a novel ultrasensitive signal-on electrochemical aptasensor has been proposed for Ochratoxin A (OTA) assay based on DNA controlled layer-by-layer assembly of dual gold nanoparticle (AuNP) conjugates. To construct the aptasensor, the 1st AuNP conjugate was prepared by simultaneous immobilization of the capture probe 2 (CP2) and bridge probe (BP) onto the AuNPs. Then, OTA aptamer was loaded onto 1st AuNPs by hybridization with CP2. The 1st AuNP conjugate can be further immobilized onto the electrode by hybridization between BP and capture probe 1 (CP1), which was pre-immobilized on Au electrode. The 2nd AuNP conjugate was prepared by immobilization of ferrocene (Fc) tagged SH-signal probe (SSP). Due to the recognition between aptamer on 1st AuNP conjugate and OTA, CP2 was reformed in the ssDNA state, which can be utilized as the anchor for immobilization of 2nd AuNP conjugate for electrochemical signal reporting. Because of the high surface-to-volume ratio and good conductivity of AuNPs, this dual AuNPs assembled nanoarchitecture finally lead to greatly improved abilities to load a large number of Fc molecules and significantly amply the electrochemical response even at a low target concentration. Both qualitative and quantitative analysis of OTA were thus realized by differential pulse voltammetry (DPV) signals, resulting in an excellent detection limit of 0.001 ppb and a wide dynamic range from 0.001 to 500 ppb over 6 orders of magnitude. Moreover, the real sample analysis towards OTA spiked wine samples was favorable, implying a great potential for practical applications. We envision that this unique dual AuNP conjugate assembly strategy would pave a new avenue for the development of versatile signal amplified electrochemical aptasensors.
Publication
Journal: Journal of Food Science
May/17/2015
Abstract
The objective of this study was to evaluate the efficacy of propolis extract (PE) to reduce lipid oxidation and microbial growth on beef patties during refrigerated storage. Beef patties were manufactured by incorporating PE in 4 different treatments: (1) Control (no PE addition); (2) commercial propolis 1 (2% w/w; CP1); (3) commercial propolis 2 (2% w/w; CP2); and (4) noncommercial propolis (2% w/w; NCP). Raw patties were wrapped with polyvinyl chloride and stored at 2 °C for 8 d. Total phenolic content (TPC), free-radical scavenging activity (FRS), and polyphenolic content of the PE were evaluated using high-performance liquid chromatography (HPLC). Lipid oxidation (thiobarbituric acid-reactive substances (TBARS), conjugated dienes (CnDs), metmyoglobin (MetMb%), pH variation, and color (L*, a*, b*, C*, and h*), and microbial growth (mesophilic and psychrotrophic bacteria) of patty samples were measured. NCP treatment demonstrated the highest FRS (64.8% at 100 μg/mL), which correlated with TPC and the presence of polyphenolic compounds. Lipid oxidation (78.54%, TBARS; 45.53%, CnD; 58.57%, MetMb) and microbial mesophilic and psychrotrophic growth (19.75 and 27.03%, respectively) values were reduced by NCP treatment in refrigerated samples after 8 d. These results indicate that PE has great potential as a natural antioxidant and antimicrobial additive to extend the shelf life of beef patties.
Publication
Journal: Chemistry - A European Journal
May/1/2017
Abstract
Although the chemistry of transition metal polyphosphide anions has attracted significant attention, there are few reports of studies in which such species have been synthesized directly from white phosphorus. [K(OEt2 )2 {Co(BIAN)(cod)}] (1, BIAN=1,2-bis(2,6-diisopropylphenylimino)acenaphthene, cod=1,5-cyclooctadiene), which is readily prepared by ligand exchange from [K(thf)x {Co(cod)2 }], reacts with P4 to afford [{K(thf)}2 {(BIAN)Co}2 (μ-η4 :η4 -P4 )] (2 a) in 61 % yield (isolated product). [{K(OEt2 )}2 {(BIAN)Co}2 (μ-η4 :η4 -P4 )] (2 b) and [K([18]crown-6)(MeCN)]2 [{(BIAN)Co}2 (μ-η4 :η4 -P4 )] (2 c) were obtained by recrystallizing 2 a from diethyl ether and acetonitrile (and using [18]crown-6 in case of 2 c). Oxidation of 2 a with [Cp2 Fe]BArF4 (one equivalent) and subsequent recrystallization of the product from different solvents gave [K(OEt2 ){(BIAN)Co}2 (μ-η4 :η4 -P4 )] (3 a) and [K(dme)4 ][{(BIAN)Co}2 (μ-η4 :η4 -P4 )] (3 b; dme=1,2-dimethoxyethane). Neutral [{(BIAN)Co}2 (μ-η4 :η4 -P4 )] (4) was obtained in moderate yield by oxidizing 2 a with two equivalents of [Cp2 Fe]BArF4 . The new complexes were characterized by NMR, EPR (in the case of 3 a), and UV/Vis spectroscopy, and elemental analysis. The molecular structures revealed by X-ray crystallography display planar cyclic or open-chain P44- units sandwiched between {(BIAN)Co} fragments.
Publication
Journal: ACS Applied Materials & Interfaces
April/6/2015
Abstract
Transparent conducting electrodes (TCEs) have been made on flat, flexible, and curved surfaces, following a crack template method in which a desired surface was uniformly spray-coated with a crackle precursor (CP) and metal (Ag) was deposited by vacuum evaporation. An acrylic resin (CP1) and a SiO2 nanoparticle-based dispersion (CP2) derived from commercial products served as CPs to produce U-shaped cracks in highly interconnected networks. The crack width and the density could be controlled by varying the spray conditions, resulting in varying template thicknesses. By depositing Ag in the crack regions of the templates, we have successfully produced Ag wire network TCEs on flat-flexible PET sheets, cylindrical glass tube, flask and lens surface with transmittance up to 86%, sheet resistance below 11 Ω/□ for electrothermal application. When used as a transparent heater by joule heating of the Ag network, AgCP1 and AgCP2 on PET showed high thermal resistance values of 515 and 409 °C cm(2)/W, respectively, with fast response (<20 s), requiring only low voltages (<5 V) to achieve uniform temperatures of ∼100 °C across large areas. Similar was the performance of the transparent heater on curved glass surfaces. Spray coating in the context of crack template is a powerful method for producing transparent heaters, which is shown for the first time in this work. AgCP1 with an invisible wire network is suited for use in proximity while AgCP2 wire network is ideal for use in large area displays viewed from a distance. Both exhibited excellent defrosting performance, even at cryogenic temperatures.
Publication
Journal: European Journal of Hospital Pharmacy: Science and Practice
June/3/2019
Abstract
To analyse the factors leading to greater satisfaction among patients attending the outpatient hospital pharmacy (OPh).A cross-sectional study was conducted of patients attending the OPh of a 1250-bed university hospital. A self-administered questionnaire for measuring outpatients' satisfaction was developed. Global satisfaction was measured on a scale of 1 to 10. Indices of perceived quality for accessibility, interpersonal professional-patient relationship and the convenience of the process were modelled through a principal component analysis using varimax rotation. The relationship between the principal components and overall satisfaction was evaluated using regression analysis.A questionnaire-based survey was conducted between May and June 2015. A total of 509 valid responses (86.9% response rate) were collected from the OPh. The overall satisfaction score was 7.81 (95% CI 7.59 to 8.04). The principal component analysis produced two components that explained 62.1% of the variance. The first component (CP1) contained questions related to the adequacy of the resources and services. The second component (CP2) contained questions about interpersonal professional-patient relationship. An additional unit in the CP2 was associated with a 3.23 increased risk of having higher satisfaction scores, while an increase of an additional unit in CP1 was associated with a 1.93 increased risk of having higher satisfaction scores.Our study shows that the factor which predicts the satisfaction of patients who come to the OPh is the quality of care provided by pharmacists-in particular, information provided, resolution of doubts, personal attention and time devoted to the patient.
Publication
Journal: Frontiers in Psychiatry
November/13/2018
Abstract
Internet gaming disorder (IGD) is a newly identified potential addiction disorder associated with compulsive internet-game playing behavior and attentional bias toward online gaming- related cues. Attentional bias toward addiction-related cues is the core feature of addiction that is associated with craving, but the pathophysiology of attentional bias in IGD is not well-understood, such as its relationship to compulsivity. In this study, we used the electrophysiological marker of late positive potential (LPP) to compare attentional bias in IGD and obsessive compulsive disorder (OCD). Twenty patients with IGD, 20 patients with OCD, and 23 healthy control (HC) subjects viewed a series of game-related, OCD-related, and neutral pictures while their event-related potentials (ERPs) were recorded. The game-related cues included in-game screen captures of popular internet games. The OCD-related cues included pictures which provokes obsessive and compulsive symptoms of contamination/washing or checking. LPPs were calculated as the mean value of amplitudes between 350 and 750 ms at the centro-parietal (CP1, CPz, CP2) and parietal (P1, Pz, P2) electrode sites. Higher LPP amplitudes were found for game-related cues in the IGD group than in the HCs, and higher LPP amplitudes were observed in the OCD group for OCD-related cues. The IGD group did not exhibit LPP changes in response to OCD-related cues. Subjective scales demonstrated increased arousal to game-related cues and OCD-related cues in both the IGD and OCD groups compared with the HC group. Increased LPPs in response to disorder-specific cues (game-related and OCD-related) were found in both IGD and OCD groups respectively, although the groups showed overlapping arousal on subjective scales. Our results indicate that LPP is a candidate neurophysiological marker for cue-related craving in IGD.
Publication
Journal: Chemistry - A European Journal
May/1/2018
Abstract
We present a combined electrochemical, kinetic, and synthetic study with a novel and easily accessible class of titanocene catalysts for catalysis in single-electron steps. The tailoring of the electronic properties of our Cp2 TiX-catalysts that are prepared in situ from readily available Cp2 TiX2 is achieved by varying the anionic ligand X. Of the complexes investigated, Cp2 TiOMs proved to be either equal or substantially superior to the best catalysts developed earlier. The kinetic and thermodynamic properties pertinent to catalysis have been determined. They allow a mechanistic understanding of the subtle interplay of properties required for an efficient oxidative addition and reduction. Therefore, our study highlights that efficient catalysts do not require the elaborate covalent modification of the cyclopentadienyl ligands.
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