Effect of the Pt–Pd molar ratio in bimetallic catalysts supported on sulfated zirconia on the gas-phase hydrodechlorination of chloromethanes

Bimetallic Pt:Pd catalysts with different molar ratios and 0.5 wt.% overall metal load supported on sulfated zirconia catalysts were synthesized and tested in the gas-phase hydrodechlorination (HDC) of chloromethanes and their mixtures. The catalysts were characterized by adsorption–desorption of N2 at −196 °C, X-ray diffraction, X-ray photoelectronic spectroscopy, temperature-programmed reduction, and aberration-corrected scanning transmission electron microscopy (STEM). The effect of the Pt:Pd molar ratio on the activity, stability, and selectivity was analyzed. The high acidity of the sulfated zirconia results in metal particles of small size (mainly <5 nm), as confirmed by STEM. The bimetallic catalysts showed higher stability than the monometallic ones, as demonstrated in long-term experiments (80 h on stream), confirming the positive effect of combining the two metallic phases. Turnover frequency (TOF) values in the range 0.0007–0.0168 s−1 and apparent activation energies between ≈41 and 44 kJ·mol−1 were obtained. TOF values for dichloromethane HDC increased with increasing mean metal particle size within the range of this work (≈1.2–2.3 nm). The catalysts with Pt:Pd molar ratios of 1:3 and 1:1 showed significantly better performance than the 3:1 one for overall dechlorination due to their higher atomic metal content and TOF at the same total metal weight load (0.5%)The authors are grateful to the Spanish ‘‘Ministerio de Economíay Competitividad (MINECO)” for financial support (ProjectsCTM2011-28352 and CTM2014-53008-

Recombinant Poliovirus circulation among healthy children immunized with oral polio vaccine in Abidjan

In order to assess the level of polio virus with natural recombinant genome and wild polio virus circulating in the environment of healthy children aged 0 to 5 years in Abidjan, 130 polio viruses made up of 26 polio type 1, 55 type 2 and 49 type 3 were identified by neutralisation test with monoclonal antibodies and restriction fragment length polymorphism (RFLP) targeting the VP1 and 3D1 gene. Four wild non Sabin-like (NSL) strains (3.1%): one type 2 and three type 3 were identified in non vaccinated children. One hundred and six (81.5%) isolates were Sabin-like, 20 (15.4%) were recombinant with the following polio virus profiles: 2 Sabin-like type 1/type 2, 3 Sabin-like type 3/type 1, 11 Sabin-like type 3/type 2 and one polio virus type 3 NSL/Sabin-like type 3. Intertypic vaccine/vaccine or vaccine/wild strain recombinant polio virus circulating among healthy children rate was high and suggested the need for a molecular surveillance of vaccine strains. Oral Polio Vaccine (OPV) strains are well-known to revert to pathogenicity in vaccines. Therefore, the long term excretion of pathogenic OPV derived strains by some vaccinees needs to be considered quite seriously. It therefore suggested that all polio virus isolated from acute flaccid paralysis (AFP) be analyzed by restriction fragment length polymorphism and sequencing of the viral genome. Key words: polio virus, recombinant virus, healthy children, Cote d'Ivoire. African Journal of Biotechnology Vol.3(5) 2004: 289-29

Antimicrobial susceptibility of extended-spectrum beta-lactamase producing Enterobacteriaceae causing urinary tract infections in Ouagadougou, Burkina Faso

Objective: To determine the frequency of extended-spectrum beta lactamase producing Enterobacteriaceae (ESBL) and other antibioticsresistant bacteria in urinary tract isolates.Study Design: prospective and experimental study.Methodology: Place and duration of study :YalgadoOuedraogo University Hospital Center, Charles De Gaulle Pediatric Hospital Center, Saint Camille Hospital and National Public Health Laboratory, Ouagadougou, from November 2014 to October 2015.AllEnterobacteriaceaestrains isolated from urinary samples of patients were identifiedusing API 20E chemical gallery (BioMerieux, France). All strains were subjected to an array of 14 antibiotics to study their drug susceptibility by using Kirby- Baeurdisk diffusion method. Detection of ESBL was carried out by double disk diffusion technique. Statistical analysis was performed by Microsoft Excel and Anova one-way GrapPad Prism version 5.01. Chi-square (χ2) test was used to determine significance. A p˂ 0.05was considered to be statistically significant.Results: A total of 324 isolates of Enterobacteriaceae were identified during the study period, including211(65%) E. coli, 75 (23%)Klebsiella spp., 18 (6%) Enterobacter spp., 11 (3%)Proteus spp., 5 (2%) Citrobacter spp., Serratia spp. 3 (1%).All the clinical isolates were susceptible to imipenem. Resistance to amikacinwas 14% (45/324); gentamicin 54% (175/324); tobramycin 58% (187/324); nalidixic acid 72% (234/324),ciprofloxacin 63% (204/324) and to cotrimoxazole 83% (269/324).The overall rate of the EBSL producing strains was 35% (114/324). Their susceptibility to antibiotics was (imipenem,amikacin, cefoxitin and fosfomycin) 100% (114/114), 93% (106/114), 74% (84/114) and 84% (96/114) respectively. ESBL positivity within individual organism group was highest inEscherichia coli 64% (73/324) followed byKlebsiellaspp. 28% (32/324), Enterobacterspp. 3% (4/324), Proteus spp. and Citrobacterspp. 2% (2/324).Conclusion: The results showeda high frequency of ESBL producing Enterobacteriaceae, especially Escherichia coli and Klebsiellaspp. The data points to theneed of routine detection and surveillance of ESBL producing bacteria in Burkina Faso.Keywords: Antimicrobial susceptibility, Enterobacteriaceae, Urine, Burkina Fas

Sr-Nd-Pb-Hf isotope results from ODP Leg 187: Evidence for mantle dynamics of the Australian-Antarctic Discordance and origin of the Indian MORB source

New high precision PIMMS Hf and Pb isotope data for 14–28 Ma basalts recovered during ODP Leg 187 are compared with zero-age dredge samples from the Australian-Antarctic Discordance (AAD). These new data show that combined Nd-Hf isotope systematics can be used as an effective discriminant between Indian and Pacific MORB source mantle domains. In particular, Indian mantle is displaced to lower εNd and higher εHf ratios compared to Pacific mantle. As with Pb isotope plots, there is almost no overlap between the two mantle types in Nd-Hf isotope space. On the basis of our new Nd-Hf isotope data, we demonstrate that Pacific MORB-source mantle was present near the eastern margin of the AAD from as early as 28 Ma, its boundary with Indian MORB-source mantle coinciding with the eastern edge of a basin-wide arcuate depth anomaly that is centered on the AAD. This observation rules out models requiring rapid migration of Pacific MORB mantle into the Indian Ocean basin since separation of Australia from Antarctica. Although temporal variations in isotopic composition can be discerned relative to the fracture zone boundary of the modern AAD at 127°E, the distribution of different compositional groups appears to have remained much the same relative to the position of the residual depth anomaly for the past 30 m.y. Thus significant lateral flow of mantle along the ridge axis toward the interface appears unlikely. Instead, the dynamics that maintain both the residual depth anomaly and the isotopic boundary between Indian and Pacific mantle are due to eastward migration of the Australian and Antarctic plates over a stagnated, but slowly upwelling, slab oriented roughly orthogonal to the ridge axis. Temporal and spatial variations in the compositions of Indian MORB basalts within the AAD can be explained by progressive displacement of shallower Indian MORB-source mantle by deeper mantle having a higher εHf composition ascending ahead of the upwelling slab. Models for the origin of the distinctive composition of the Indian MORB-source based on recycling of a heterogeneous enriched component that consist of ancient altered ocean crust plus<10% pelagic sediment are inconsistent with Nd-Hf isotope systematics. Instead, the data can be explained by a model in which Indian mantle includes a significant proportion of material that was processed in the mantle wedge above a subduction zone and was subsequently mixed back into unprocessed upper mantle

A Trial of Early Antiretrovirals and Isoniazid Preventive Therapy in Africa

BACKGROUND: In sub-Saharan Africa, the burden of human immunodeficiency virus (HIV)-associated tuberculosis is high. We conducted a trial with a 2-by-2 factorial design to assess the benefits of early antiretroviral therapy (ART), 6-month isoniazid preventive therapy (IPT), or both among HIV-infected adults with high CD4+ cell counts in Ivory Coast. METHODS: We included participants who had HIV type 1 infection and a CD4+ count of less than 800 cells per cubic millimeter and who met no criteria for starting ART according to World Health Organization (WHO) guidelines. Participants were randomly assigned to one of four treatment groups: deferred ART (ART initiation according to WHO criteria), deferred ART plus IPT, early ART (immediate ART initiation), or early ART plus IPT. The primary end point was a composite of diseases included in the case definition of the acquired immunodeficiency syndrome (AIDS), non-AIDS-defining cancer, non-AIDS-defining invasive bacterial disease, or death from any cause at 30 months. We used Cox proportional models to compare outcomes between the deferred-ART and early-ART strategies and between the IPT and no-IPT strategies. RESULTS: A total of 2056 patients (41% with a baseline CD4+ count of ≥500 cells per cubic millimeter) were followed for 4757 patient-years. A total of 204 primary end-point events were observed (3.8 events per 100 person-years; 95% confidence interval [CI], 3.3 to 4.4), including 68 in patients with a baseline CD4+ count of at least 500 cells per cubic millimeter (3.2 events per 100 person-years; 95% CI, 2.4 to 4.0). Tuberculosis and invasive bacterial diseases accounted for 42% and 27% of primary end-point events, respectively. The risk of death or severe HIV-related illness was lower with early ART than with deferred ART (adjusted hazard ratio, 0.56; 95% CI, 0.41 to 0.76; adjusted hazard ratio among patients with a baseline CD4+ count of ≥500 cells per cubic millimeter, 0.56; 95% CI, 0.33 to 0.94) and lower with IPT than with no IPT (adjusted hazard ratio, 0.65; 95% CI, 0.48 to 0.88; adjusted hazard ratio among patients with a baseline CD4+ count of ≥500 cells per cubic millimeter, 0.61; 95% CI, 0.36 to 1.01). The 30-month probability of grade 3 or 4 adverse events did not differ significantly among the strategies. CONCLUSIONS: In this African country, immediate ART and 6 months of IPT independently led to lower rates of severe illness than did deferred ART and no IPT, both overall and among patients with CD4+ counts of at least 500 cells per cubic millimeter. (Funded by the French National Agency for Research on AIDS and Viral Hepatitis; TEMPRANO ANRS 12136 ClinicalTrials.gov number, NCT00495651.)

Mycolactone Diffuses into the Peripheral Blood of Buruli Ulcer Patients - Implications for Diagnosis and Disease Monitoring.

BACKGROUND: Mycobacterium ulcerans, the causative agent of Buruli ulcer (BU), is unique among human pathogens in its capacity to produce a polyketide-derived macrolide called mycolactone, making this molecule an attractive candidate target for diagnosis and disease monitoring. Whether mycolactone diffuses from ulcerated lesions in clinically accessible samples and is modulated by antibiotic therapy remained to be established. METHODOLOGY/PRINCIPAL FINDING: Peripheral blood and ulcer exudates were sampled from patients at various stages of antibiotic therapy in Ghana and Ivory Coast. Total lipids were extracted from serum, white cell pellets and ulcer exudates with organic solvents. The presence of mycolactone in these extracts was then analyzed by a recently published, field-friendly method using thin layer chromatography and fluorescence detection. This approach did not allow us to detect mycolactone accurately, because of a high background due to co-extracted human lipids. We thus used a previously established approach based on high performance liquid chromatography coupled to mass spectrometry. By this means, we could identify structurally intact mycolactone in ulcer exudates and serum of patients, and evaluate the impact of antibiotic treatment on the concentration of mycolactone. CONCLUSIONS/SIGNIFICANCE: Our study provides the proof of concept that assays based on mycolactone detection in serum and ulcer exudates can form the basis of BU diagnostic tests. However, the identification of mycolactone required a technology that is not compatible with field conditions and point-of-care assays for mycolactone detection remain to be worked out. Notably, we found mycolactone in ulcer exudates harvested at the end of antibiotic therapy, suggesting that the toxin is eliminated by BU patients at a slow rate. Our results also indicated that mycolactone titres in the serum may reflect a positive response to antibiotics, a possibility that it will be interesting to examine further through longitudinal studies

Lanreotide autogel every 6 weeks compared with Lanreotide microparticles every 3 weeks in patients with well differentiated neuroendocrine tumors: A Phase III study

BACKGROUND. The noninferiority of a 6-week dosing schedule of lanreotide Auto-gel (Lan ATG) at a dose of 120 mg compared with a 3-week dosing schedule of lanreotide microparticles (Lan MP) at a dose of 60 mg was investigated in patients with neuroendocrine tumors (NET). METHODS. Patients who had sporadic, well differentiated NET with a low grade of malignancy were recruited for this open-label, Phase 111, multicenter trial. Patients were randomized to receive either 3 deep subcutaneous injections of Lan ATG (120 mg, every 6 weeks) or 6 intramuscular injections of Lan MP (60 mg, every 3 weeks). Tumor markers, tumor size, and symptoms were assessed between baseline and Week 18. Success was classified as a response that ranged from disappearance to an increase &lt; 25% in tumor marker, tumor size, or symptom frequency. RESULTS. Sixty patients were randomized, and 46 patients completed the study. Both for tumor markers and for tumor size, Lan ATG was not inferior to Lan MP (55% and 59% of patients responded on tumor markers, respectively; 68% and 66% of patients responded on tumor size, respectively). There were too few symptomatic patients to compare carcinoid symptoms. Both treatments were tolerated well, and no safety concerns were identified. CONCLUSIONS. Lan ATG at a dose of 120 mg every 6 weeks was as effective for controlling NET as Lan MP at a dose of 60 mg every 3 weeks

Pervasive melt percolation reactions in ultra-depleted refractory harzburgites at the Mid-Atlantic Ridge, 15° 20′N : ODP Hole 1274A

Author Posting. © The Authors, 2006. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Contributions to Mineralogy and Petrology 153 (2007): 303-319, doi:10.1007/s00410-006-0148-6.ODP Leg 209 Site 1274 mantle peridotites are highly refractory in terms of lack of residual clinopyroxene, olivine Mg# (up to 0.92) and spinel Cr# (~0.5), suggesting high degree of partial melting (>20%). Detailed studies of their microstructures show that they have extensively reacted with a pervading intergranular melt prior to cooling in the lithosphere, leading to crystallization of olivine, clinopyroxene and spinel at the expense of orthopyroxene. The least reacted harzburgites are too rich in orthopyroxene to be simple residues of low-pressure (spinel field) partial melting. Cu-rich sulfides that precipitated with the clinopyroxenes indicate that the intergranular melt was generated by no more than 12% melting of a MORB mantle or by more extensive melting of a clinopyroxene-rich lithology. Rare olivine-rich lherzolitic domains, characterized by relics of coarse clinopyroxenes intergrown with magmatic sulfides, support the second interpretation. Further, coarse and intergranular clinopyroxenes are highly depleted in REE, Zr and Ti. A two-stage partial melting/melt-rock reaction history is proposed, in which initial mantle underwent depletion and refertilization after an earlier high pressure (garnet field) melting event before upwelling and remelting beneath the present-day ridge. The ultra-depleted compositions were acquired through melt re-equilibration with residual harzburgites.Funding for this research was provided by Centre National de la Recherche Scientifique-Institut National des Sciences de l’Univers (Programme Dynamique et Evolution de la Terre Interne)

Fluorescence‐based bowel anastomosis perfusion evaluation: results from the IHU‐IRCAD‐EAES EURO‐FIGS registry

Background: Anastomotic leakage (AL) is one of the dreaded complications following surgery in the digestive tract. Near-infrared fluorescence (NIRF) imaging is a means to intraoperatively visualize anastomotic perfusion, facilitating fluorescence image-guided surgery (FIGS) with the purpose to reduce the incidence of AL. The aim of this study was to analyze the current practices and results of NIRF imaging of the anastomosis in digestive tract surgery through the EURO-FIGS registry. Methods: Analysis of data prospectively collected by the registry members provided patient and procedural data along with the ICG dose, timing, and consequences of NIRF imaging. Among the included upper-GI, colorectal, and bariatric surgeries, subgroup analysis was performed to identify risk factors associated with complications. Results: A total of 1240 patients were included in the study. The included patients, 74.8% of whom were operated on for cancer, originated from 8 European countries and 30 hospitals. A total of 54 surgeons performed the procedures. In 83.8% of cases, a pre-anastomotic ICG dose was administered, and in 60.1% of cases, a post-anastomotic ICG dose was administered. A significant difference (p &lt; 0.001) was found in the ICG dose given in the four pathology groups registered (range: 0.013–0.89&nbsp;mg/kg) and a significant (p &lt; 0.001) negative correlation was found between the ICG dose and BMI. In 27.3% of the procedures, the choice of the anastomotic level was guided by means of NIRF imaging which means that in these cases NIRF imaging changed the level of anastomosis which was first decided based on visual findings in conventional white light imaging. In 98.7% of the procedures, the use of ICG partly or strongly provided a sense of confidence about the anastomosis. A total of 133 complications occurred, without any statistical significance in the incidence of complications in the anastomoses, whether they were ICG-guided or not. Conclusion: The EURO-FIGS registry provides an insight into the current clinical practice across Europe with respect to NIRF imaging of anastomotic perfusion during digestive tract surgery