WTEC panel report on research submersibles and undersea technologies

This report covers research submersibles and related subsea technologies in Finland, France, Russia, Ukraine and the United Kingdom. Manned, teleoperated, and autonomous submersibles were of interest. The panel found that, in contrast to the United States, Europe is making substantial progress in cooperative and coordinated research in subsea technology, including the development of standards. France is a leader in autonomous vehicle technology. Because much less was known a priori about the technologies in Russia and Ukraine, there were more new findings in those countries than in those Western European nations visited. However, Russia and Ukraine have a sizeable (and currently underutilized) infrastructure in this field, including a highly educated and experienced manpower pool, impressive (in some cases unique) facilities for physical testing, extensive fleets of seagoing research vessels capable of long voyages, and state-of-the-art facilities for conducting oceanographic investigations. The panel visited newly-formed commercial companies associated with long-standing submersible R&D and production centers in Russia and Ukraine. So far, these new efforts are undercapitalized, and as such represent opportunities at very low cost for Western nations, as detailed in the site reports

Improved detection of Pneumocystis jirovecii in upper and lower respiratory tract specimens from children with suspected pneumocystis pneumonia using real-time PCR: a prospective study

<p>Abstract</p> <p>Background</p> <p><it>Pneumocystis </it>pneumonia (PCP) is a major cause of hospitalization and mortality in HIV-infected African children. Microbiologic diagnosis relies predominantly on silver or immunofluorescent staining of a lower respiratory tract (LRT) specimens which are difficult to obtain in children. Diagnosis on upper respiratory tract (URT) specimens using PCR has been reported useful in adults, but data in children are limited. The main objectives of the study was (1) to compare the diagnostic yield of PCR with immunofluorescence (IF) and (2) to investigate the usefulness of upper compared to lower respiratory tract samples for diagnosing PCP in children.</p> <p>Methods</p> <p>Children hospitalised at an academic hospital with suspected PCP were prospectively enrolled. An upper respiratory sample (nasopharyngeal aspirate, NPA) and a lower respiratory sample (induced sputum, IS or bronchoalveolar lavage, BAL) were submitted for real-time PCR and direct IF for the detection of <it>Pneumocystis </it><it>jirovecii</it>. A control group of children with viral lower respiratory tract infections were investigated with PCR for PCP.</p> <p>Results</p> <p>202 children (median age 3.3 [inter-quartile range, IQR 2.2 - 4.6] months) were enrolled. The overall detection rate by PCR was higher than by IF [180/349 (52%) vs. 26/349 (7%) respectively; p < 0.0001]. PCR detected more infections compared to IF in lower respiratory tract samples [93/166 (56%) vs. 22/166 (13%); p < 0.0001] and in NPAs [87/183 (48%) vs. 4/183 (2%); p < 0.0001]. Detection rates by PCR on upper (87/183; 48%) compared with lower respiratory tract samples (93/166; 56%) were similar (OR, 0.71; 95% CI, 0.46 - 1.11). Only 2/30 (6.6%) controls were PCR positive.</p> <p>Conclusion</p> <p>Real-time PCR is more sensitive than IF for the detection of <it>P. jirovecii </it>in children with PCP. NPA samples may be used for diagnostic purposes when PCR is utilised. Wider implementation of PCR on NPA samples is warranted for diagnosing PCP in children.</p

Cost-Effectiveness Analysis of Diagnostic Options for Pneumocystis Pneumonia (PCP)

Diagnosis of Pneumocystis jirovecii pneumonia (PCP) is challenging, particularly in developing countries. Highly sensitive diagnostic methods are costly, while less expensive methods often lack sensitivity or specificity. Cost-effectiveness comparisons of the various diagnostic options have not been presented.We compared cost-effectiveness, as measured by cost per life-years gained and proportion of patients successfully diagnosed and treated, of 33 PCP diagnostic options, involving combinations of specimen collection methods [oral washes, induced and expectorated sputum, and bronchoalveolar lavage (BAL)] and laboratory diagnostic procedures [various staining procedures or polymerase chain reactions (PCR)], or clinical diagnosis with chest x-ray alone. Our analyses were conducted from the perspective of the government payer among ambulatory, HIV-infected patients with symptoms of pneumonia presenting to HIV clinics and hospitals in South Africa. Costing data were obtained from the National Institutes of Communicable Diseases in South Africa. At 50% disease prevalence, diagnostic procedures involving expectorated sputum with any PCR method, or induced sputum with nested or real-time PCR, were all highly cost-effective, successfully treating 77-90% of patients at $26-51 per life-year gained. Procedures using BAL specimens were significantly more expensive without added benefit, successfully treating 68-90$189-232 per life-year gained. A relatively cost-effective diagnostic procedure that did not require PCR was Toluidine Blue O staining of induced sputum ($25 per life-year gained, successfully treating 68$109 per life-year gained) compared with several molecular diagnostic options.For diagnosis of PCP, use of PCR technologies, when combined with less-invasive patient specimens such as expectorated or induced sputum, represent more cost-effective options than any diagnostic procedure using BAL, or chest x-ray alone

Self-Closing and Self-Healing Multi-Material Suction Cups for Energy-Efficient Vacuum Grippers

While vacuum grippers offer an economical solution, the environmental impact of energy waste through their suction cups (SCs) cannot be overlooked. This waste stems from three key factors: i) air losses from idle SCs arranged in arrays, ii) inadequate sealing on target surfaces leading to air leaks, and iii) damage from sharp objects resulting in leaking perforations. To overcome these challenges, in this article, a comprehensive approach is presented that involves the development of a i) self‐closing, ii) multi‐material, and iii) self‐healing system based on reversible elastomers cross‐linked via the Diels–Alder (DA) reaction. The system incorporates a fully autonomous self‐closing mechanism to prevent energy waste in SC arrays during periods of non‐contact. Fluid–structure interaction simulations are utilized to analyze the design. Versatility and stability are achieved by incorporating hyper‐flexible and stiff elastomers in a multi‐material design, supported by covalent DA cross‐links that ensure robustness through high‐strength multi‐material interfaces. These DA cross‐links also enable self‐healing capabilities, allowing the SCs to recover from macroscopic damages within 1 day at ambient conditions or in a single hour with mild heating (80–90 °C), restoring full performance. Additionally, in the article, a recycling method is introduced for multi‐material SCs based on the mechanical separation of reversible polymers.</jats:p

A generic methodology to study self-healing properties of thermo-reversible polymer networks

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A remendable polymer network based on reversible covalent bonding for coating applications

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Studying the healing behavior at a microsopic scale

Research in the field of smart materials that exhibit self-repair mechanisms has greatly expanded over the last few years. This is especially true for polymers and polymer composite materials. One class of self-healing polymer materials is the reversible polymer network systems that use dynamic covalent bonds as a means to repair sustained damage. Currently a range of different dynamic covalent bonds is considered, of which the reversible Diels-Alder chemistry has drawn the most attention. Reversible covalent bonds have been incorporated into polymer network structures based on the Diels-Alder reaction between a furan and a maleimide [1-2]. Repair of sustained damage can be established by means of heating-used selfhealing in bulk materials as well as in coating applications. The aim of this research is to study the healing mechanism and healing kinetics at the microscopic scale and to compare this healing mechanism for different polymer network structures and chemistries. The self-healing behavior is studied with local and surface analysis techniques, including Atomic Force Microscopy as an important tool. A better understanding of the healing mechanism at the microscopic level will lead to a better understanding of the macroscopic healing phenomena and ultimately to the adaptation of the polymer network structure to obtain the desired material properties, such as mechanical properties, healing conditions and additional functional properties. The research can then be extended towards self-healing polymer composites, with e.g. a reversible polymer matrix, to evaluate the recovery of the composite material properties [3]

Unlocking the potential of self-healing and recyclable ionic elastomers for soft robotics applications

Celebrating 10 Years of Materials Horizons: 10th Anniversary CollectionIn the field of soft robotics, current materials face challenges related to their load capacity, durability, and sustainability. Innova tive solutions are required to address these problems beyond conventional strategies, which often lack long-term ecological viability. This study aims to overcome these limitations using mechanically robust, self-healing, and recyclable ionic elastomers based on carboxylated nitrile rubber (XNBR). The designed materials exhibited excellent mechanical properties, including tensile strengths (TS) exceeding 19 MPa and remarkable deformability, with maximum elongations (EB) over 650%. Moreover, these materials showed high self-healing capabilities, with 100% recovery efficiency of TS and EB at 110 8C after 3 to 5 h, and full recyclability, preserving their mechanical performance even after three recycling cycles. Furthermore, they were also moldable and readily scalable. Tendon-driven soft robotic grippers were successfully developed out of ionic elastomers, illustrating the potential of self-healing and recyclability in the field of soft robotics to reduce maintenance costs, increase material durability, and improve sustainability.The authors acknowledge the State Research Agency of Spain (AEI) for the research contract (PID2019-107501RB-I00/AEI/ 10.13039/501100011033) and M. Hernández Santana for Ramón y Cajal contract (RYC-2017-22837). The authors acknowledge the Spanish National Research Council (CSIC) for the iLink+ contract (LINKA20325) and S. Utrera-Barrios for the predoctoral contract (PIE-202060E183). The authors acknow ledge the Fonds Wetenschappelijk Onderzoek (FWO) for the personal grants of S. Terryn (1100416N) and J. Brancart (12E1123N). All authors also acknowledge Arlanxeo for kindly providing XNBR and the PTI+ SusPlast from CSIC for their support.Peer reviewe

Multiple action self-healing coatings for the corrosion protection of metals (abstract)

Materials Science and EngineeringMechanical, Maritime and Materials Engineerin