277 research outputs found
Aroma absorption in rapeseed oil using rotating packed bed
An increasing consumers’ call for natural aromas fuels the development of biotechnological aroma production. Although aroma fermentation is quite advantageous, especially severe product losses of volatile compounds through the bioreactor off-gas may challenge the downstream processing. The application of novel process intensification methods to overcome the common drawbacks of conventional apparatuses might be helpful on a way to commercial competitiveness of biotechnological aromas. This study explored the suitability of rotating packed bed (RPB), a rotating mass transfer enhancing machine, for the absorption of model aroma compounds in rapeseed oil. Increasing the rotation speed from 500 to 2750 rpm led to two- to threefold higher absorption efficiencies at elsewise constant conditions. Aiming for an enriched aromatic intermediate, 2.5 L of rapeseed oil was processed in a recycle for 200 minutes, and a final concentration of benzaldehyde of 0.323 ± 0.026 g/Loil was achieved. Compared to packed columns, the RPB outperforms at equal packing depth or requires less packing area to deliver same efficiency. Especially, the use of custom 3D-printed spiral packing with elaborated wall film flow combined with rotation supported liquid distribution allows using absorbents with viscosities as high as 100 mPa·s at low pressure drop increase. However, small dimensions severely limit the performance of a laboratory-scale RPB as the casing contributes disproportionally to mass transfer
Molecular characterization of Listeria monocytogenes isolates from a small-scale meat processor in Montenegro, 2011-2014
The presence of Listeria monocytogenes was evaluated in a small-scale meat processing facility in Montenegro during 2011-2014. L. monocytogenes isolates from traditional meat products and environmental swabs were subjected to a) molecular characterization b) serotyping by both multiplex PCR and next generation sequencing (NGS) c) potential antimicrobial resistance (AMR) was assessed by extraction of specific genes from NGS data and d) screening for the presence of some disinfectant resistance markers. Overall, traditional meat products were contaminated, most likely from incoming raw materials, with 4 major specific STs of L. monocytogenes (ST515, ST8, ST21, ST121) representing 4 clonal complexes (CC1, CC8, CC21, CC121) identified during the four-year period. These strains belonged to serogroup IIa which predominated, followed by IVb (ST515, CC1). The strains from environmental swabs belonged, exclusively, to ST21 and were isolated from cutting board and floor swabs in 2011. Furthermore, we found Tn6188, a novel transposon conferring tolerance to BC, to be specific to sequence type ST121. In addition, antimicrobial resistance genes mprF and fosX were present in clonal complexes CC21 and CC121, while complexes CC8 and CC1 exclusively harbored the mprF antimicrobial resistance gene.This is the peer-reviewed version of the article: Zuber, I.; Lakićević, B.; Pietzka, A.; Milanov, D.; Đorđević, V.; Karabasil, N.; Teodorović, V.; Ruppitsch, W.; Dimitrijević, M. Molecular Characterization of Listeria Monocytogenes Isolates from a Small-Scale Meat Processor in Montenegro, 2011-2014. Food Microbiology 2019, 79, 116–122. [https://doi.org/10.1016/j.fm.2018.12.005
Wine fingerprinting using a bio-geochemical approach
The wine sector is a billion euro business and therefore subjected to multiple attempts of fraudulent practices. This
requires the development of rapid and reliable methods to detect such situations. Several methodologies have been developed
based on the chemical profiles of the wines, but they are limited due to the environmental conditions that cannot be controlled.
The use of DNA-based detection systems are an emergent research field that have been extended to a wide variety of food products
and are still the most reliable methods for varietal identification. However these methods are not suitable for geographical
determination. Soil related fingerprints have a primary role considering that there is a relationship between the elemental composition
of wine and the composition of the provenance soil. WineBioCode is a project aiming to define the best strategy for wine
authenticity based on a multidisciplinary approach. Two DNA-based strategies have been developed based on Real-time PCR and
a label free optical biosensor platform. Both platforms enabled successful identification of specific DNA-targets when applied to
Vitis vinifera L., and can be applied throughout the grape-wine chain. The methods are complementary and can be used in different
situations, according to the requirements. The geographical evaluation has been assessed by the strontium 87Sr/86Sr isotope
ratio determination involving soil evaluation in the vineyards followed by its assay in the wine samples. The results are being
integrated in order to establish the best procedure to be undertaken for wine fingerprinting, including varietal composition and
geographical origin, therefore fulfilling the requirements of the geographical denominations in wine certificatio
Rapid identification of bacteria associated with Acute Oak Decline by high-resolution melt analysis
© 2016 The Society for Applied Microbiology Two Gram-negative Enterobacteriaceae, Gibbsiella quercinecans and Brenneria goodwinii, are frequently isolated from oak suffering from Acute Oak Decline. These two species are difficult to identify based on colony morphology, carbohydrate utilization or 16S rRNA gene sequence, and identification using gyrB gene sequencing is time-consuming and laborious. A rapid identification technique, based on high-resolution melt analysis of the atpD gene, was designed to efficiently process numerous isolates from an increasing number of affected woodlands and parks. Principal component analysis of the resulting melt curves from strains of G.quercinecans, B.goodwinii and their close phylogenetic relatives allowed differentiation into distinct clusters based on species or subspecies identity. Significance and Impact of the Study: Acute Oak Decline is an increasing threat to Britain's native oak population. Two novel bacterial species both belonging to the family Enterobacteriaceae, Gibbsiella quercinecans and Brenneria goodwinii, are thought to play an important role in symptom development. Here, we describe a rapid identification technique using high-resolution melt analysis of the atpD gene able to assign isolates to either G.quercinecans or B.goodwinii in a single assay, greatly reducing the time taken to identify if either or both of these species are present in symptomatic oak
Fabrication of a NCD microelectrode array for amperometric detection with micrometer spatial resolution
Review of multidrug-resistant and extensively drug-resistant TB: global perspectives with a focus on sub-Saharan Africa
Tuberculosis (TB) remains a global emergency and is responsible for 1.7 million deaths annually. Widespread global misuse of isoniazid and rifampicin over three decades has resulted in emergence of the ominous spread of multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) globally. These difficult to treat resistant forms of TB are increasingly seen in Asia, Eastern Europe, South America and sub-Saharan Africa, disrupting TB and HIV control programmes. We review the latest available global epidemiological and clinical evidence on drug-resistant TB in HIV-infected and uninfected populations, with focus on Africa where data are scanty because of poor diagnostic and reporting facilities. The difficult management and infection control problems posed by drug-resistant TB in HIV-infected patients are discussed. Given the increasing current global trends in MDR-TB, aggressive preventive and management strategies are urgently required to avoid disruption of global TB control efforts. The data suggest that existing interventions, public health systems and TB and HIV programmes must be strengthened significantly. Political and funder commitment is essential to curb the spread of drug-resistant TB
Innovative Vacuum Arc Thruster for CubeSat Constellations
Abstract: The University of the Federal Armed Forces (UniBwM) is currently developing an innovative electric propulsion system for small satellites with extremly low space, mass and power budget. Satellites with these characteristics were built by the JustusMaximilians-Universität Würzburg (JMUW) within the international CubeSat project. the Bavarian government UniBwM and JMUW are working together to equip the new pico satellite UWE-4 (Universität Würzburg Experimentalsatellit 4) with a sufficient propulsion system for fine positioning and attitude control. JMUW is responsible for the development of the satellite and the integration of the propulsion system which is currently under development at UniBwM based on the so called Vacuum Arc Thruster. To demonstrate the positioning ability of the system the mission of UWE-4 is to chase another CubeSat and to hold its relative position. Together with the strict restrictions of the CubeSat this gives some serious challenges to be solved
Structural investigation of substoichiometry and solid solution effects in Ti2Al(Cx,N1−x)y compounds
Fatal Pseudomonas aeruginosa pneumonia in a previously healthy woman was most likely associated with a contaminated hot tub
Community-acquired pneumonia due to Pseudomonas aeruginosa in previously healthy individuals is a rare disease that is associated with high fatality. On 14 February 2010 a previously healthy 49-year-old woman presented to an emergency room with signs and symptoms of pneumonia, 2 days after returning from a spa holiday in a wellness hotel. Blood cultures and respiratory specimens grew P. aeruginosa. Despite adequate antimicrobial therapy, the patient died of septic multiorgan failure on day nine of hospitalization. On February 26, nine water samples were taken from the hotel facilities used by the patient: In the hot tub sample 37,000 colony-forming units of P. aeruginosa/100 ml were detected. Two of five individual colonies from the primary plate used for this hot tub water sample were found to be genetically closely related to the patients’ isolates. Results from PFGE, AFLP and MLST analysis allowed the two lung isolates gained at autopsy and the whirlpool bathtub isolates to be allocated into one cluster. The patient most likely acquired P. aeruginosa from the contaminated water in the hotel’s hot tub. The detection of P. aeruginosa in high numbers in a hot tub indicates massive biofilm formation in the bath circulation and severe deficiencies in hygienic maintenance. The increasing popularity of hot tubs in hotels and private homes demands increased awareness about potential health risks associated with deficient hygienic maintenance
Adjuvant Radiotherapy in Patients with Squamous Cell Carcinoma of the Oral Cavity or Oropharynx and Solitary Ipsilateral Lymph Node Metastasis (pN1) : A Prospective Multicentric Cohort Study
(1) Background: Evaluation of impact of adjuvant radiation therapy (RT) in patients with
oral squamous cell carcinoma of the oral cavity/oropharynx (OSCC) of up to 4 cm (pT1/pT2) and
solitary ipsilateral lymph node metastasis (pN1). A non-irradiated group with clinical follow-up was
chosen for control, and survival and quality of life (QL) were compared; (2) Methods: This prospective
multicentric comprehensive cohort study included patients with resected OSCC (pT1/pT2, pN1,
and cM0) who were allocated into adjuvant radiation therapy (RT) or observation. The primary
endpoint was overall survival. Secondary endpoints were progression-free survival and QL after
surgery; (3) Results: Out of 27 centers, 209 patients were enrolled with a median follow-up of 3.4 years.
An amount of 137 patients were in the observation arm, and 72 received adjuvant irradiation. Overall
survival did not differ between groups (hazard ratio (HR) 0.98 [0.55–1.73], p = 0.94). There were fewer
neck metastases (HR 0.34 [0.15–0.77]; p = 0.01), as well as fewer local recurrences (HR 0.41 [0.19–0.89];
p = 0.02) under adjuvant RT. For QL, irradiated patients showed higher values for the symptom scale
pain after 0.5, two, and three years (all p < 0.05). After six months and three years, irradiated patients
reported higher symptom burdens (impaired swallowing, speech, as well as teeth-related problems
(all p < 0.05)). Patients in the RT group had significantly more problems with mouth opening after
six months, one, and two years (p < 0.05); (4) Conclusions: Adjuvant RT in patients with early SCC of
the oral cavity and oropharynx does not seem to influence overall survival, but it positively affects
progression-free survival. However, irradiated patients report a significantly decreased QL up to
three years after therapy compared to the observation group
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