It is well known that synthetic diamond exhibits unique properties which make it an attractive material for a broad range of applications in the particle-detection field. In particular, thanks to its ...radiation hardness and availability in larger sizes, the polycrystalline (pc) diamond sample, grown by chemical vapour deposition (CVD), is especially suitable for online beam-monitoring applications, provided it demonstrates excellent counting performances. The present work reports the counting efficiency of a large 20.0×20.0×0.3 mm3 pcCVD diamond detector irradiated by 62 MeV/nucl. carbon beams. The parameter under study was estimated at different particle rates by employing a combination of different detector counters in a sandwich configuration. Results show a counting efficiency of ∼ 95% up to 0.7 MHz particle rate. The pcCVD diamond detector under study was selected among other prepared devices by studying their leakage current and photocurrent characteristics under X-ray irradiation.
Enterococcus is ubiquitous in human feces and has been adopted as a useful indicator of human fecal pollution in water. Although regular enterococci monitoring only examines their numbers, ...identifying human-specific Enterococcus species or genotypes could help discriminate human fecal contamination from other environmental sources. We documented a new approach to characterize enterococci using a high-throughput 16S rRNA gene amplicon sequencing platform from Quanti Trays after following the counting of the most probable numbers of enterococci. We named this method QT-AMP (Quanti-Tray-based amplicon sequencing). We tested surface water samples collected from three rivers in southwest Florida. We detected 11 Enterococcus species from 45 samples in 1.1 million sequence reads. The method detected three rare species and eight cosmopolitan species (Enterococcus faecalis, E. faecium, E. casseliflavus, E. hirae, E. mundtii, E. gallinarum, E. avium, and E. durans) which have been commonly documented in previous studies. The approximate detection level of QT-AMP was four orders of magnitude higher than regular 16S rRNA gene amplicon sequencing. The current Enterolert MPN method only provides quantitative information but now we can look into the relative abundance of Enterococci species composition by accompanying Illumina sequencing. This QT-AMP could be a useful tool to streamline the quantification and identification of enterococci and could be used in various water management projects and human health risk assessment.
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•Molecular characterization of enterococci after Enterolert enrichment•The primer set used (27f-519r) could potentially differentiate over 50 Enterococcus species.•We identified eight cosmopolitan Enterococcus species and three rare species.•This method ensures the wide coverage of Enterococcus species in environments.
•High-concentration (14 mM) hydrogen peroxide destructs Microcystis bloom within one day in mesocosm.•Hydrogen peroxide treatment elevated dissolved oxygen (150%) compared to control ...(103%).•Planctomycetota and Gammaproteobacteria dominated the microbiome after treatment.•Post-treatment microbiome retained functionality for microcystin degradation.
Hydrogen peroxide has gained popularity as an environmentally friendly treatment for cyanobacterial harmful algal blooms (cHABs) that takes advantage of oxidative stress sensitivity in cyanobacteria at controlled concentrations. Higher concentrations of hydrogen peroxide treatments may seem appealing for more severe cHABs but there is currently little understanding of the environmental impacts of this approach. Of specific concern is the associated microbial community, which may play key roles in the succession/recovery process post-treatment. To better understand impacts of a high concentration treatment on non-target microbial communities, we applied a hydrogen peroxide spray equating to a total volume concentration of 14 mM (473 mg/L, 0.04%) to 250 L mesocosms containing Microcystis bloom biomass, monitoring treatment and control mesocosms for 4 days. Cyanobacteria dominated control mesocosms throughout the experiment while treatment mesocosms experienced a 99% reduction, as determined by bacterial amplicon sequencing, and a 92% reduction in bacterial cell density within 1 day post-treatment. Only the bacterial community exhibited signs of regrowth, with a fold change of 9.2 bacterial cell density from day 1 to day 2. Recovery consisted of succession by Planctomycetota (47%) and Gammaproteobacteria (17%), which were likely resilient due to passive cell component compartmentalization and rapid upregulation of dnaK and groEL oxidative stress genes, respectively. The altered microbiome retained beneficial functionality of microcystin degradation through a currently recognized but unidentified pathway in Gammaproteobacteria, resulting in a 70% reduction coinciding with bacterial regrowth. There was also an 81% reduction of both total nitrogen and phosphorus, as compared to 91 and 93% in the control, respectively, due to high expressions of genes related to nitrogen (argH, carB, glts, glnA) and phosphorus (pntAB, phoB, pstSCB) cycling. Overall, we found a portion of the bacterial community was resilient to the high-concentration hydrogen peroxide treatment, resulting in Planctomycetota and Gammaproteobacteria dominance. This high-concentration treatment may be suitable to rapidly end cHABs which have already negatively impacted the aquatic environment rather than allow them to persist.
We report the case of a 14 year old healthy boy, who was admitted six weeks after being injured by a palm tree thorn, with limping caused by pain and swelling in his right knee. An ultrasound ...examination revealed a foreign body in the posterior lateral aspect of the right knee. Pantoea agglomerans was identified in the synovial fluid. The patient underwent two arthrotomies and was treated with amoxicillin-clavulanate intravenously for three weeks. The postoperative course was uneventful, and joint function returned to normal. A review of the literature between 1953 and 2002 revealed that bacterial growth after plant thorn injuries is reported infrequently. Yet when reported, Pantoea agglomearns is the most common organism found. Therefore, it must be considered and suspected in “aseptic” cases of arthritis, when there is a history of a plant thorn injury. We also emphasise the efficacy of ultrasound examination in these cases to identify the presence and location of a plant thorn.
Bonding of a variety of inorganic and organic polymers as multi-layered structures is one of the main challenges for biochip production even to date, since the chemical nature of these materials ...often does not allow easy and straight forward bonding and proper sealing. After selection of an appropriate method to bond the chosen materials to form a complex biochip, function and stability of bonding either requires qualitative burst tests or expensive mechanical multi-test stations, that often do not have the right adaptors to clamp biochip slides without destruction. Therefore, we have developed a simple and inexpensive bonding test based on 3D printed transmission elements that translate compressive forces via manual compression, hand press or hydraulic press compression into shear and tensile force. Mechanical stress simulations showed that design of the bonding geometry and size must be considered for bonding tests since the stress distribution thus bonding strength heavily varies with size but also with geometry. We demonstrate the broad applicability of our 3D printed bonding test system by testing the most frequent bonding strategies in combination with the respective most frequently used biochip material in a force-to-failure study. All evaluated materials are biocompatible and used in cell-based biochip devices. This study is evaluating state-of-the-art bonding approaches used for sealing of microfluidic biochips including adhesive bonding, plasma bonding, solvent bonding as well as bonding mediated by amino-silane monolayers or even functional thiol-ene epoxy biochip materials that obviate intermediate adhesive layers.
Objectives
Automated cell counters have replaced manual enumeration of cells in blood and most body fluids. However, due to the unreliability of automated methods at very low cell counts, most ...laboratories continue to perform labor‐intensive manual counts on many or all cerebrospinal fluid (CSF) samples. This multicenter clinical trial investigated if the GloCyte System (Advanced Instruments, Norwood, MA), a recently FDA‐approved automated cell counter, which concentrates and enumerates red blood cells (RBCs) and total nucleated cells (TNCs), is sufficiently accurate and precise at very low cell counts to replace all manual CSF counts.
Methods
The GloCyte System concentrates CSF and stains RBCs with fluorochrome‐labeled antibodies and TNCs with nucleic acid dyes. RBCs and TNCs are then counted by digital image analysis. Residual adult and pediatric CSF samples obtained for clinical analysis at five different medical centers were used for the study. Cell counts were performed by the manual hemocytometer method and with the GloCyte System following the same protocol at all sites. The limits of the blank, detection, and quantitation, as well as precision and accuracy of the GloCyte, were determined.
Results
The GloCyte detected as few as 1 TNC/μL and 1 RBC/μL, and reliably counted as low as 3 TNCs/μL and 2 RBCs/μL. The total coefficient of variation was less than 20%. Comparison with cell counts obtained with a hemocytometer showed good correlation (>97%) between the GloCyte and the hemocytometer, including at very low cell counts.
Conclusions
The GloCyte instrument is a precise, accurate, and stable system to obtain red cell and nucleated cell counts in CSF samples. It allows for the automated enumeration of even very low cell numbers, which is crucial for CSF analysis. These results suggest that GloCyte is an acceptable alternative to the manual method for all CSF samples, including those with normal cell counts.
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