223 research outputs found
Rapid Screening of Alicyclobacillus acidoterrestris Spoilage of Fruit Juices by Electronic Nose: A Confirmation Study
Early screening of Alicyclobacillus spp. in fruit juices is a major applicative goal for the food industry, since juice contamination can lead to considerable loss of quality, and subsequently, to economic damages for juice producers. This paper presents an accurate study to assess and confirm the EOS507 electronic nose’s (EN) ability of diagnosing Alicyclobacillus acidoterrestris spoilage in artificially contaminated fruit juices. The authors experimental results have shown that the EOS507 can early identify, just after 24 hours from inoculation, contaminated orange and pear juices with an excellent classification rate close to 90% and with a detection threshold as low as 103 cfu/ml. In apple juice the detection threshold was about 105 cfu/ml, thus requiring longer incubation times (72 hours). PLS regression of EOS507 data can be also used to predict with fair accuracy the colony-forming units concentration of the bacteria. These results were supported by the GC/MS/MS measurements of specific chemical markers, such as guaiacol
Single crystal diamond membranes for nanoelectronics
© 2018 The Royal Society of Chemistry. Single crystal, nanoscale diamond membranes are highly sought after for a variety of applications including nanophotonics, nanoelectronics and quantum information science. However, so far, the availability of conductive diamond membranes has remained an unreachable goal. In this work we present a complete nanofabrication methodology for engineering high aspect ratio, electrically active single crystal diamond membranes. The membranes have large lateral directions, exceeding ∼500 × 500 μm2 and are only several hundreds of nanometers thick. We further realize vertical single crystal p-n junctions made from the diamond membranes that exhibit onset voltages of ∼10 V and a current of several mA. Moreover, we deterministically introduce optically active color centers into the membranes, and demonstrate for the first time a single crystal nanoscale diamond LED. The robust and scalable approach to engineer the electrically active single crystal diamond membranes offers new pathways for advanced nanophotonic, nanoelectronic and optomechanical devices employing diamond
Modulation of pro- and anti-apoptotic factors in human melanoma cells exposed to histone deacetylase inhibitors
Valproic acid (VPA, 2-propylpentanoic acid) is an established
drug in the long-term therapy of epilepsy. Recently,
VPA was demonstrated to inhibit histone deacetylases
(HDACs) class I enzyme at therapeutically relevant concentrations,
thereby, mimicking the prototypical histone
deacetylase inhibitors, tricostatin A (TSA) or suberoylanilide
hydroxamic acid (SAHA). In the present study, we
investigated the cellular effects of VPA, TSA and SAHA
on four human melanoma cell lines (WM115, WM266,
A375, SK-Mel28) with particular reference to the modulation
of regulators of apoptosis, including Bcl-2, BclXL,
Mcl-1, Apaf-1, BclXs, NOXA, TRAIL-R1, TRAIL-R2, caspase
8, and survivin). Firstly, we found that VPA induced
apoptosis in two of the four human melanoma cell lines,
while both TSA and SAHA exhibited an antiproliferative
and apoptotic effects in all four cell lines, a different
expression of Bcl-2 and BclXL/S occurred. On the other
hand, SAHA and VPA modulated differently pro- and antiapoptotic
factors. In particular, the treatment with VPA
enhanced the level of expression of survivin only in VPAresistant
cell lines, whereas down-regulation of survivin
was induced by VPA and SAHA in VPA-sensitive cells.
In the latter, since activation of caspase 8 was documented,
a receptor-mediated apoptosis was suggested.
Taken together, our results suggest that HDAC inhibitors
may represent a promising therapeutic strategy to treat
melanoma
Direct but not indirect co-culture with osteogenically differentiated human bone marrow stromal cells increases RANKL/OPG ratio in human breast cancer cells generating bone metastases
Background: Bone metastases arise in nearly 70% of patients with advanced breast cancer, but the complex metastatic process has not been completely clarified yet. RANKL/RANK/OPG pathway modifications and the crosstalk between metastatic cells and bone have been indicated as potential drivers of the process. Interactions between tumor and bone cells have been studied in vivo and in vitro, but specific effects of the direct contact between human metastatic cells and human bone cells on RANKL/RANK/OPG pathway have not been investigated. Findings: We directly co-cultured bone metastatic human breast cancer cells (BOKL) with osteo-differentiated human mesenchymal cells (BMSCs) from 3 different donors. BMSCs and BOKL were then enzymatically separated and FACS
sorted. We found a significant increase in the RANKL/OPG ratio as compared to control, which was not observed in BOKL cultured in medium conditioned by BMSCs, neither in BOKL directly cultured with fibroblasts or medium conditioned by fibroblasts. Direct co-culture with osteo-differentiated BMSCs caused BOKL aggregation while proliferation was not affected by co-culture. To more specifically associate RANKL expression to osteogenic differentiation degree of BMSCs, we determined their osteogenic markers expression and matrix calcification
relative to osteoblasts and fibroblasts.
Conclusions: In conclusion, our co-culture model allowed to demonstrate for the first time that direct contact but not paracrine interactions between human metastatic breast cancer cells and bone cells has a significant effect on RANKL/OPG expression in bone metastatic cells. Furthermore, only direct contact with the bone microenvironment induced BOKL clustering without however significantly influencing their proliferation and migration
Does PGE1 vasodilator prevent orthopaedic implant-related infection in diabetes? Preliminary results in a mouse model
Background: Implant-related infections are characterized by bacterial colonization and biofilm formation on the prosthesis. Diabetes represents one of the risk factors that increase the chances of prosthetic infections because of related severe peripheral vascular disease. Vasodilatation can be a therapeutic option to overcome diabetic vascular damages and increase the local blood supply. In this study, the effect of a PGE1 vasodilator on the incidence of surgical infections in diabetic mice was investigated. Methodology: A S. aureus implant-related infection was induced in femurs of diabetic mice, then differently treated with a third generation cephalosporin alone or associated with a PGE1 vasodilator. Variations in mouse body weight were evaluated as index of animal welfare. The femurs were harvested after 28 days and underwent both qualitative and quantitative analysis as micro-CT, histological and microbiological analyses. Results: The analysis performed in this study demonstrated the increased host response to implant-related infection in diabetic mice treated with the combination of a PGE1 and antibiotic. In this group, restrained signs of infections were identified by micro-CT and histological analysis. On the other hand, the diabetic mice treated with the antibiotic alone showed a severe infection and inability to successfully respond to the standard antimicrobial treatment. Conclusions: The present study revealed interesting preliminary results in the use of a drug combination of antibiotic and vasodilator to prevent implant-related Staphylococcus aureus infections in a diabetic mouse model
Recent Southern Ocean warming and freshening driven by greenhouse gas emissions and ozone depletion
Closed-loop Control of a Vibrant Duct Gravimetric Feeder
Abstract -In this work the control system for a gravimetric feeder with vibrant duct for polymer extrusion process has been designed. The plant considered in this paper is a blending machine that mixes up to six components: each component is measured by a dedicated vibrant duct. All components are mixed directly in the chambers of the extruder screw. The mass delivered by each meter is measured by a load cell. The control objectives are: accurate mass flow estimate on the basis of the weight; accurate mass flow regulation; minimum settling time; robustness of the controller parameters against the variation of material and structure of meter
Diabetic Mouse Model of Orthopaedic Implant-Related Staphylococcus Aureus Infection
BACKGROUND:
Periprosthetic bacterial infections represent one of the most challenging orthopaedic complications that often require implant removal and surgical debridement and carry high social and economical costs. Diabetes is one of the most relevant risk factors of implant-related infection and its clinical occurrence is growing worldwide. The aim of the present study was to test a model of implant-related infection in the diabetic mouse, with a view to allow further investigation on the relative efficacy of prevention and treatment options in diabetic and non-diabetic individuals.
METHODOLOGY:
A cohort of diabetic NOD/ShiLtJ mice was compared with non-diabetic CD1 mice as an in vivo model of S. aureus orthopaedic infection of bone and soft tissues after femur intramedullary pin implantation. We tested control and infected groups with 1
7103 colony-forming units of S. aureus ATCC 25923 strain injected in the implant site. At 4 weeks post-inoculation, host response to infection, microbial biofilm formation, and bone damage were assessed by traditional diagnostic parameters (bacterial culture, C-reactive protein and white blood cell count), histological analysis and imaging techniques (micro computed tomography and scanning electron microscopy).
RESULTS:
Unlike the controls and the CD1 mice, all the diabetic mice challenged with a single inoculum of S. aureus displayed severe osteomyelitic changes around the implant.
CONCLUSIONS:
Our findings demonstrate for the first time that the diabetic mouse can be successfully used in a model of orthopaedic implant-related infection. Furthermore, the same bacteria inoculum induced periprosthetic infection in all the diabetic mice but not in the controls. This animal model of implant-related infection in diabetes may be a useful tool to test in vivo treatments in diabetic and non-diabetic individuals
Matriptase and MET are prominently expressed at the site of bone metastasis in renal cell carcinoma: immunohistochemical analysis
Modeling Staphylococcus epidermidis-Induced Non-Unions : Subclinical and Clinical Evidence in Rats
S. epidermidis is one of the leading causes of orthopaedic infections associated with biofilm formation on implant devices. Open fractures are at risk of S. epidermidis transcutaneous contamination leading to higher non-union development compared to closed fractures. Although the role of infection in delaying fracture healing is well recognized, no in vivo models investigated the impact of subclinical low-grade infections on bone repair and non-union. We hypothesized that the non-union rate is directly related to the load of this commonly retrieved pathogen and that a low-grade contamination delays the fracture healing without clinically detectable infection. Rat femurs were osteotomized and stabilized with plates. Fractures were infected with a characterized clinical-derived methicillin-resistant S. epidermidis (10(3), 10(5), 10(8) colony forming units) and compared to uninfected controls. After 56 days, bone healing and osteomyelitis were clinically assessed and further evaluated by micro-CT, microbiological and histological analyses. The biofilm formation was visualized by scanning electron microscopy. The control group showed no signs of infection and a complete bone healing. The 10(3) group displayed variable response to infection with a 67% of altered bone healing and positive bacterial cultures, despite no clinical signs of infection present. The 10(5) and 10(8) groups showed severe signs of osteomyelitis and a non-union rate of 83-100%, respectively. The cortical bone reaction related to the periosteal elevation in the control group and the metal scattering detected by micro-CT represented limitations of this study. Our model showed that an intra-operative low-grade S. epidermidis contamination might prevent the bone healing, even in the absence of infectious signs. Our findings also pointed out a dose-dependent effect between the S. epidermidis inoculum and non-union rate. This pilot study identifies a relevant preclinical model to assess the role of subclinical infections in orthopaedic and trauma surgery and to test specifically designed diagnostic, prevention and therapeutic strategies
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