[en] RIMNET (Radioactive Incident Monitoring Network) Phase 2, launched in the UK in 1994, is a substantial emergency response information system. As well as being central to the national plans for coping with a future overseas nuclear accident, it provides a good communications and information exchange resource which can be applied to potential domestic nuclear accidents and other aspects of environmental contamination. (UK)

[en] To enhance emergency response management NRPB has introduced an advanced information handling and map display facility. The NRPB Emergency Response Information System (NERIS) provides a central resource which holds, displays and analyses the available information on an accidental release of radioactivity. The bringing together of the commercial tools of computerised map display and database technology, capable of storing geographically referenced information, provided the initial building blocks for the development of NERIS. The rapid manipulation of the large amounts of data used by NERIS is achieved by the use of complex software on powerful computers and a substantial investment of both staff time and resources. The synthesis of these products with the analysis tools under development by NRPB staff will provide a system which will greatly enhance the organisation's emergency response capability. The need to assess the consequences of an accident and give advice on countermeasure strategies and actions will inevitably place high demands on NRPB staff. NERIS will enable a more complete understanding of the situation to be gained and give staff the time and tools to cope effectively with all exigencies. (Author)

[en] Purpose: To quantify the dosimetric impact of interfractional shoulder motion on targets in the low neck for head and neck patients treated with volume modulated arc therapy (VMAT). Methods: Three patients with head and neck cancer were selected. All three required treatment to nodal regions in the low neck in addition to the primary tumor. The patients were immobilized during simulation and treatment with a custom thermoplastic mask covering the head and shoulders. One VMAT plan was created for each patient utilizing two full 360° arcs. A second plan was created consisting of two superior VMAT arcs matched to an inferior static AP supraclavicular field. A CT-on-rails alignment verification was performed weekly during each patient's treatment course. The weekly CT images were registered to the simulation CT and the target contours were deformed and applied to the weekly CT. The two VMAT plans were copied to the weekly CT datasets and recalculated to obtain the dose to the low neck contours. Results: The average observed shoulder position shift in any single dimension relative to simulation was 2.5 mm. The maximum shoulder shift observed in a single dimension was 25.7 mm. Low neck target mean doses, normalized to simulation and averaged across all weekly recalculations were 0.996, 0.991, and 1.033 (Full VMAT plan) and 0.986, 0.995, and 0.990 (Half-Beam VMAT plan) for the three patients, respectively. The maximum observed deviation in target mean dose for any individual weekly recalculation was 6.5%, occurring with the Full VMAT plan for Patient 3. Conclusion: Interfractional variation in dose to low neck nodal regions was quantified for three head and neck patients treated with VMAT. Mean dose was 3.3% higher than planned for one patient using a Full VMAT plan. A Half-Beam technique is likely a safer choice when treating the supraclavicular region with VMAT

[en] Mineralized type I collagen (collagen I) nanofibers and their nanofibril bundles make up the microstructure of natural bone tissue, which range from nanometers to micrometers. However, attempts to achieve this hierarchically assembled structure in vitro have been unsuccessful. In this study, we added osteonectin into the collagen I solution, either at a high or low weight ratio (osteonectin: collagen I = 1:30 or 1:90) before co-precipitation. Results indicated that spindle-like nano-hydroxyapatite (nano-HA) was deposited on collagen/osteonectin and pure osteonectin (control) groups. Furthermore, transmission electron microscope (TEM) and scanning electron microscope (SEM) results showed that the assembled mineralized fiber bundles were formed randomly at different levels from 50 nm, 250 nm to 1100 nm. However, when we replaced collagen I with collagen II, osteonectin addition did not induce the formation of mineralized fiber bundles. The participation of osteonectin in the assembly of the mineralized fibers could provide new insights into the novel mineralization function of osteonectin for bone development in vivo and advancing new biomimetic methods for bone graft applications.

[en] The development of biodegradable polymeric scaffolds with surface properties that dominate interactions between the material and biological environment is of great interest in biomedical applications. In this regard, poly-ε-caprolactone (PCL) nanofibrous scaffolds were fabricated by an electrospinning process and surface modified by a simple plasma treatment process for enhancing the Schwann cell adhesion, proliferation and interactions with nanofibers necessary for nerve tissue formation. The hydrophilicity of surface modified PCL nanofibrous scaffolds (p-PCL) was evaluated by contact angle and x-ray photoelectron spectroscopy studies. Naturally derived polymers such as collagen are frequently used for the fabrication of biocomposite PCL/collagen scaffolds, though the feasibility of procuring large amounts of natural materials for clinical applications remains a concern, along with their cost and mechanical stability. The proliferation of Schwann cells on p-PCL nanofibrous scaffolds showed a 17% increase in cell proliferation compared to those on PCL/collagen nanofibrous scaffolds after 8 days of cell culture. Schwann cells were found to attach and proliferate on surface modified PCL nanofibrous scaffolds expressing bipolar elongations, retaining their normal morphology. The results of our study showed that plasma treated PCL nanofibrous scaffolds are a cost-effective material compared to PCL/collagen scaffolds, and can potentially serve as an ideal tissue engineered scaffold, especially for peripheral nerve regeneration.

[en] Primary sputtering mechanisms are conventionally grouped in terms of the categories collisional, thermal, and electronic. With pulsed photons one must, in addition, consider the emission of droplets and fragments in thermochemical processes. Pulsed photons also lead to the situation that the density of emitted particles is sufficiently high for gas-dynamic effects to enter and for the system therefore to lose memory of the primary mechanism. One then distinguishes secondary mechanisms which include outflow, as when a finite reservoir expands, effusion, effusive release from the outer surface without recondensation, and recondensation, effusive release with recondensation. If the photon pulse interacts with the emitted particles then still further secondary mechanisms are relevant due to energy deposition in the plume of emitted particles as well as due to ionization. Finally, the laser-pulse sputtering of the polymer PMMA (polymethylmethacrylate) and the superconductor YBCO (YBa₂Cu₃O_7-x) is discussed on the basis of explicit photographs of the sputtered particles. In the case of PMMA there are two groups of particles, the first group having primary and secondary mechanisms which are presently unestablishable but the second group being reasonably attributed to thermal primary release and to secondary behavior of the effusion (or recondensation) type. In the case of YBCO there is only one group of particles having a primary mechanism which is almost certainly electronic and a secondary mechanism which is tentatively identified with outflow. (orig.)

[en] A bioabsorbable nanofibrous scaffold was developed for early adhesion of mesenchymal stem cells (MSCs). Collagen nanofibers with diameters of 430 ± 170 nm were fabricated by electrospinning. Over 45% of the MSC population adhered to this collagen nanofiber after 30 min at room temperature. Remarkably, collagen-coated P(LLA-CL) electrospun nanofibers were almost as efficient as collagen nanofibers whereas collagen cast film did not enhance early capture when it was applied on cover slips. The adhesive efficiency could be further increased to over 20% at 20 min and over 55% at 30 min when collagen nanofibers were grafted with monoclonal antibodies recognizing CD29 or CD49a. These data demonstrate that the early adhesive behavior is highly dependent on both the surface texture and the surface chemistry of the substrate. These findings have potential applications for early capture of MSCs in an ex vivo setting under time constraints such as in a surgical setting.

[en] The time required for osseointegration with a metal implant having a smooth surface ranges from three to six months. We hypothesized that biomimetic coating surfaces with poly(lactic-co-glycolic acid) (PLGA)/collagen fibers and nano-hydroxyapatite (n-HA) on the implant would enhance the adhesion of mesenchymal stem cells. Therefore, this surface modification of dental and bone implants might enhance the process of osseointegration. In this study, we coated PLGA or PLGA/collagen (50:50 w/w ratio) fiber on Ti disks by modified electrospinning for 5 s to 2 min; after that, we further deposited n-HA on the fibers. PLGA fibers of fiber diameter 0.957 ± 0.357 µm had a contact angle of 9.9 ± 0.3° and PLGA/collagen fibers of fiber diameter 0.378 ± 0.068 µm had a contact angle of 0°. Upon n-HA incorporation, all the fibers had a contact angle of 0° owing to the hydrophilic nature of n-HA biomolecule. The cell attachment efficiency was tested on all the scaffolds for different intervals of time (10, 20, 30 and 60 min). The alkaline phosphatase activity, cell proliferation and mineralization were analyzed on all the implant surfaces on days 7, 14 and 21. Results of the cell adhesion study indicated that the cell adhesion was maximum on the implant surface coated with PLGA/collagen fibers deposited with n-HA compared to the other scaffolds. Within a short span of 60 min, 75% of the cells adhered onto the mineralized PLGA/collagen fibers. Similarly by day 21, the rate of cell proliferation was significantly higher (p ≤ 0.05) on the mineralized PLGA/collagen fibers owing to enhanced cell adhesion on these fibers. This enhanced initial cell adhesion favored higher cell proliferation, differentiation and mineralization on the implant surface coated with mineralized PLGA/collagen fibers.

[en] Highlights: • The premise plumbing microbiome of a 50-year-old university building was characterized. • Biofilms were dominated with biofilm-formers and emerging opportunistic pathogens (OPs). • Legionella spp. was used as a model OP to assess its presence in the premise plumbing system. • Discrepancies remain between culture-dependent and -independent outcomes for Legionella spp. The premise plumbing portion of drinking water distribution systems (DWDS) has several characteristics that may favor microbial growth in the form of biofilms. These microbial communities are implicated as infectious sources for the spread of opportunistic waterborne pathogens by supporting their complex ecology and transmission through DWDS outlets to susceptible individuals. However, there is limited understanding of the drinking water biofilms in real premise plumbing networks due to challenges with accessibility. Using a combination of culture-dependent and culture-independent approaches, this study comprehensively characterized the premise plumbing microbiome of a 50-year-old university building, inclusive of water and biofilm samples. Microbial diversity in the water samples were more taxonomically diverse in comparison to the mature drinking water biofilms, which were dominated with biofilm-formers and opportunistic pathogens, such as Mycobacterium spp. A model opportunistic pathogen, Legionella spp., was only detectable in water samples using quantitative PCR but could not be detected in any of the drinking water biofilms using either qPCR or culture-dependent approaches, highlighting the limitations of detection methods in these environments. This study presents preliminary findings on the microbial dynamics and complexity in premise plumbing networks, which may support public health management and the development of strategies to eliminate microbial risks to human health.