Enhanced host–guest electrochemical recognition of herbicide MCPA using a b-cyclodextrin carbon nanotube sensor

An electrochemical sensor for the determination of the chlorophenoxy herbicide MCPA has been developed, based on a combination of multi-walled carbon nanotubes with incorporated b-cyclodextrin and a polyaniline film modified glassy carbon electrode. The proposed molecular host–guest recogni-tion based sensor has a high electrochemical sensitivity for the determination of MCPA. The electrochemical behaviour of MCPA at the chemically modified electrode was investigated in detail by cyclic voltammetry. The results indicate that the b-CD/MWCNT modified glassy carbon electrode exhibits efficient electrocatalytic oxidation of MCPA with high sensitivity, stability and lifetime. The analytical characteristics of this film were used for the quantitative determination of MCPA in natural waters. Cyclic voltammetry in phosphate buffer solution at pH 6.0, allowed the development of a method to determine MCPA, without any previous steps of extraction, clean-up, or derivatization, in the range of 10–100 mmol L-1, with a detection limit of 0.99 mmol L-1 in water. The results were statistically compared with those obtained through an established high-performance liquid chromato-graphy technique, no significant differences having been found between the two methods.info:eu-repo/semantics/publishedVersio

Pseudomonas aeruginosa displays an epidemic population structure.

peer reviewedBacteria can have population structures ranging from the fully sexual to the highly clonal. Despite numerous studies, the population structure of Pseudomonas aeruginosa is still somewhat contentious. We used a polyphasic approach in order to shed new light on this issue. A data set consisting of three outer membrane (lipo)protein gene sequences (oprI, oprL and oprD), a DNA-based fingerprint (amplified fragment length polymorphism), serotype and pyoverdine type of 73 P. aeruginosa clinical and environmental isolates, collected across the world, was analysed using biological data analysis software. We observed a clear mosaicism in the results, non-congruence between results of different typing methods and a microscale mosaic structure in the oprD gene. Hence, in this network, we also observed some clonal complexes characterized by an almost identical data set. The most recent clones exhibited serotypes O1, 6, 11 and 12. No obvious correlation was observed between these dominant clones and habitat or, with the exception of some recent clones, geographical origin. Our results are consistent with, and even clarify, some seemingly contradictory results in earlier epidemiological studies. Therefore, we suggest an epidemic population structure for P. aeruginosa, comparable with that of Neisseria meningitidis, a superficially clonal structure with frequent recombinations, in which occasionally highly successful epidemic clones arise

Size Doesn't Matter: Towards a More Inclusive Philosophy of Biology

notes: As the primary author, O’Malley drafted the paper, and gathered and analysed data (scientific papers and talks). Conceptual analysis was conducted by both authors.publication-status: Publishedtypes: ArticlePhilosophers of biology, along with everyone else, generally perceive life to fall into two broad categories, the microbes and macrobes, and then pay most of their attention to the latter. ‘Macrobe’ is the word we propose for larger life forms, and we use it as part of an argument for microbial equality. We suggest that taking more notice of microbes – the dominant life form on the planet, both now and throughout evolutionary history – will transform some of the philosophy of biology’s standard ideas on ontology, evolution, taxonomy and biodiversity. We set out a number of recent developments in microbiology – including biofilm formation, chemotaxis, quorum sensing and gene transfer – that highlight microbial capacities for cooperation and communication and break down conventional thinking that microbes are solely or primarily single-celled organisms. These insights also bring new perspectives to the levels of selection debate, as well as to discussions of the evolution and nature of multicellularity, and to neo-Darwinian understandings of evolutionary mechanisms. We show how these revisions lead to further complications for microbial classification and the philosophies of systematics and biodiversity. Incorporating microbial insights into the philosophy of biology will challenge many of its assumptions, but also give greater scope and depth to its investigations

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

Impact of silicon substrate, iron contamination and perimeter on saturation current and noise in n+p diodes

In this article two different generations of silicon material from the early-eighties and the mid-nineties are compared. The impact of iron contamination and perimeter on the current voltage characteristics and low-frequency noise of n+p diodes was investigated. All diodes showed an ideality factor one over at least seven decades in current. Iron contamination reduces the minority carrier lifetime and thus increases the saturation current. The higher the oxygen content in the silicon substrate, the lower the minority carrier lifetime. At a given forward current this results in a lower number of excess minority carriers outside the depletion region and a higher I/fnoise. Czochralski-grown wafers with a high oxygen content have the highest l/fnoise. Epitaxial and floating-zone wafers did not show I/fnoise above I Hz for currents smaller than 0.2 mA. Above 0.2 mA l/f noise was observed because of series resistance fluctuations, with SI oc P/f.F or Czochralski-grown wafers with the lowest values for minority carrier lifetimes, the noise spectral density was found to be proportional to SI cc Zk/fAX-‘, with k z 3/2 and A the diode area. This indicates the absence of perimeter and series resistance effects. A model is proposed to explain the current and area dependence of the noise in diodes. In this model a position dependent I/’ noise parameter a is assume

Microbial metabolomics: Past, present and future methodologies

Applied Science

Antimicrobial susceptibility patterns of Arcobacter butzleri and Arcobacter cryaerophilus strains isolated from humans and broilers.

The MICs of five antimicrobial agents were determined by the agar dilution method for 98 Arcobacter butzleri and 28 Arcobacter cryaerophilus strains from humans, and poultry. With gentamicin, a MIC of 16 microg/ml was recorded for one A. butzleri strain isolated from poultry, whereas for the other strains MICs ranged from 0.25 to 4 microg/ml. With ciprofloxacin, a bimodal distribution of susceptibility levels was seen for human A. butzleri isolates (0.015-0.03 versus 0.12-0.25), whereas MICs for 65 of the 68 A. butzleri poultry strains ranged from 0.12 to 0.5 microg/ml and three strains from three different broilers were resistant with a MIC of 16 microg/ml. One A. cryaerophilus strain from poultry was resistant to erythromycin at a MIC of 128 microg/ml, whereas MICs for the other Arcobacter strains ranged from 2 to 32 microg/ml. No difference in susceptibility or resistance among the human and poultry strains tested was observed with doxycycline and nalidixic acid. The presence of acquired resistance to erythromycin and ciprofloxacin among poultry isolates is a matter of concern, because the two antimicrobials are generally prescribed as first-line drugs for the treatment of infections with Campylobacteraceae in humans.Journal Articleinfo:eu-repo/semantics/publishe

Use of selective medium for Burkholderia cepacia isolation in respiratory samples from cystic fibrosis patients Uso de meio seletivo para identificação de cepas de Burkholderia cepacia em amostras de trato respiratório de pacientes portadores de fibrose cística

Burkholderia cepacia colonizes cystic fibrosis (CF) patients. We evaluated the impact of the use of a selective medium in the rate of B. cepacia recovery from respiratory samples of CF patients. During a 6-month period, respiratory samples were collected from 106 CF patients and cultivated on selective media including a B. cepacia selective medium. Confirmation of the identity of B. cepacia isolates was carried out by species specific PCR and determination of genomovar status performed by a sequential PCR approach. Results of B. cepacia isolation during this period were compared to the preceding two years, when the sample processing was identical except for the lack of the B. cepacia selective medium. B. cepacia was isolated in 11/257 (4.2%) of the samples using the selective medium, in contrast with the preceding two years, when it was isolated in 6/1029 samples (0.58%), p < 0.0001. Identity of all 11 isolates was confirmed by PCR and genomovar determination was accomplished in all but one isolate. These results suggest that the use of a selective medium increases recovery rate of B. cepacia from respiratory samples.<br>A Burkholderia cepacia coloniza os pacientes portadores de fibrose cística (FC). Avaliamos o impacto do uso de um meio seletivo no isolamento de B. cepacia em amostras de secreção respiratória de pacientes portadores de FC. Durante um período de 6 meses, amostras de trato respiratório foram colhidas de 106 pacientes com FC e cultivadas em meios seletivos incluindo um meio para isolamento de B. cepacia. A identidade das cepas de B. cepacia foi confirmada através de PCR espécie específica e a determinação do genomovar ou subespécie realizada através de reações seqüenciais de PCR. Os resultados de isolamento de B. cepacia durante este período foram comparados com os dois anos precedentes, quando o processamento das amostras era idêntico, exceto pela utilização do meio seletivo para B. cepacia. B. cepacia foi isolada em 11/257 (4,2%) amostras usando o meio seletivo, e em apenas 6/1029 (0,58%) nos dois anos precedentes (p < 0,0001). A identidade destas 11 cepas foi confirmada e a determinação do genomovar obtida em 10/11. Estes resultados sugerem que o uso do meio seletivo aumenta a freqüência de isolamento de B. cepacia em amostras de trato respiratório de pacientes portadores de FC