Abstract A silver-releasing antibacterial hydrogel was developed that simultaneously allowed for silver nanoparticle formation and gel curing. Water-soluble polyethylene glycol (PEG) polymers were ...synthesized that contain reactive catechol moieties, inspired by mussel adhesive proteins, where the catechol containing amino acid 3,4-dihydroxyphenylalanine (DOPA) plays an important role in the ability of the mussel to adhere to almost any surface in an aqueous environment. We utilized silver nitrate to oxidize polymer catechols, leading to covalent cross-linking and hydrogel formation with simultaneous reduction of Ag(I). Silver release was sustained for periods of at least two weeks in PBS solution. Hydrogels were found to inhibit bacterial growth, consistent with the well-known antibacterial properties of silver, while not significantly affecting mammalian cell viability. In addition, thin hydrogel films were found to resist bacterial and mammalian cell attachment, consistent with the antifouling properties of PEG. We believe these materials have a strong potential for antibacterial biomaterial coatings and tissue adhesives, due to the material-independent adhesive properties of catechols.
LLC resonant converter with significant resonant inductance is proposed for designing an adjustable wide-range regulated voltage source. Large resonant inductance increases output voltage adjustment ...range and conversion efficiency, particularly at light loads. Soft switching is achieved for all power devices under all operating conditions by choosing the dead time and maximum switching frequency properly and operating in the converter's inductive region. Using a power-factor-correction (PFC) converter reduces the resonant converter's output voltage dependence to the variations of the main ac input voltage. Thus, the compensation of the load variations and the wide-range adjustment of the regulated output voltage can be achieved by using small switching frequency variations. The proposed method has been used to implement an adjustable wide-range voltage source (35-165 V dc), as an ion implanter arc power supply. An almost flat efficiency curve with maximum value of 94% has been achieved for the converter. Its output current can change from no load to 3 A dc.
•Built environments contribute to efforts to explain public bike usage.•Empirical knowledge on associations of built environment with public bike usage is not transferable among cities.•Collecting ...local empirical knowledge on travel behavior is critical for developing bike-friendly built environments.
This article presents a transnational comparison study to clarify the difference in the associations of built environment with public bike usage in three cities in eastern Asia. This study sampled passengers entering or leaving metro stations in seven neighborhoods in Beijing, Taipei, and Tokyo for home-based work trips. Their mode choices of connecting travels between trip origins/destinations and metro stations were analyzed using logit and latent class models. Empirical evidence reveals that the associations of built environments with public bike usage of the study cities rarely accord with one other. Results are unable to support that empirical knowledge on the association of built environment with public bike usage is transferable among transnational cities despite their geographical and cultural proximity. Collecting local empirical knowledge on travel behavior is critical for developing bike-friendly built environments for a city.
Electricity markets are significantly more volatile than other comparable financial or commodity markets. This study examines volatility spillover effects across different regions in the Australian ...National Electricity Market (NEM), aiming at providing a better understanding of the transmission of risks in a multi-regional context. Our analysis is based on the econometric framework originally proposed by Diebold and Yilmaz (2009, 2012). We conduct both a static and a dynamic assessment of aggregated spillover effects as well as their directional decomposition between the individual regions. We find that volatility spillovers are typically more pronounced between physically interconnected markets. We further relate the dynamic spillover patterns to specific short-term market events as well as long-term changes in the share of renewable energy, fuel mix, generation capacity, and the implementation of a Carbon Pricing Mechanism. Our findings provide important insights to market participants and regulators with regard to cross-regional trading of electricity, developing risk management strategies, and building additional interconnector infrastructure to facilitate regional market integration in the NEM.
•We investigate volatility spillover effects across regional spot electricity markets in Australia.•Spillover effects are significantly influenced by regional proximity and interconnectors.•Victoria is the most influential market as the only constant net spillover transmitter.•Both magnitude and direction of spillover effects are time-varying and event-dependent.•In recent years, system-wide aggregate volatility spillovers have increased.
This brief proposes a simple but effective strategy to improve wake-up operation in energy-autonomous systems which exploits Charge Pump (CP) circuits to boost voltage directly from energy harvester ...generators. By means of few auxiliary diodes and parasitic junctions, the CP is managed to retain the charges in the pumping capacitors when the harvesting power source is not able to feed the system, thereby reducing the rise time and input energy demand during the start-up phase. Simulation results using a 65-nm CMOS technology confirm the potentialities of the proposed strategy and show a reduction of the rise time and the input energy higher than 20% as compared with the traditional topology.
•Five novel Dmrt genes were identified and characterized in M. rosenbergii.•Four MroDmrt genes exhibit sexual dimorphic expression pattern among gonads and AG.•Silencing of Mr-IAG reduced the ...expression of two MroDmrts in the AG.
The doublesex and mab-3 related transcription factor (Dmrt) gene family is known to be related to the sexual regulators doublesex of arthropods and mab-3 of annelids and to hold highly conserved functions in sexual determination and differentiation across phyla. Here, we report a study of the Dmrt gene family in the freshwater prawn Macrobrachium rosenbergii, a crustacean whose sexual differentiation has been widely researched. A wide transcriptomic screen, from the embryo to the adult M. rosenbergii, identified five novel Dmrt genes (MroDmrts) and confirmed two known MroDmrts. The seven MroDmrts encode proteins of 275–855 amino acids; each protein contained at least one conserved DNA-binding DM domain, which is typical of Dmrt proteins, and five proteins contained 1–4 transactivation domains (TADs). Importantly, in the embryonic, larval and post-larval stages, MroDmrt genes exhibited time-dependent expression patterns rather than sex-specific expression. In-silico screening of the expression of the MroDmrt genes in adult males revealed the enrichment of MroiDmrt1b and MroiDmrt1c in the androgenic gland (AG) as compared to the eyestalks. In vivo silencing of the androgenic gland insulin-like (IAG) encoding gene significantly decreased the expression of the above two Dmrt genes, while not affecting the expression of control genes, thereby suggesting the possible role of these two genes in the IAG-switch and in sex-differentiation processes.
A nanoscale RGD-pyrene-graphene oxide (GO) biosensor was prepared for real-time in situ detection of a cancer cell surface marker, integrin αvβ3. This nanoscale GO-based biosensor is simple, robust, ...sensitive and of high selectivity. It can also be adapted to other cancer cell surface marker evaluation systems.
La crise sanitaire provoquée par la pandémie de Covid-19 a eu un impact particulièrement sévère sur la santé mentale des étudiants. Cette période de la vie, entre adolescence et âge adulte, est ...lourde d’enjeux déterminants : remaniement des relations familiales, autonomisation, implication dans les relations amoureuses et érotiques, choix essentiels : de métier, de partenaire. Pour certains, peuvent s’ajouter la mobilité ou l’exil quand les études l’exigent, ainsi que les préoccupations économiques. C’est donc une période charnière, pour la plupart féconde, mais aussi de grande vulnérabilité psychique. Cette vulnérabilité a été renforcée par l’isolement et les perturbations de la scolarité. Ce sont les effets qui ont été les plus marquants de la crise sanitaire sur les étudiants. Le BAPU FSEF Paris V a pour mission de permettre aux étudiants d’avoir accès à des psychothérapies psychodynamiques. L’équipe a dû adapter son dispositif aux changements qualitatifs et quantitatifs de la demande dans la période de la crise sanitaire. Nous évoquerons ces changements en les illustrant d’un exemple clinique. Les effets à long terme de la crise seront également abordés.
The health crisis brought on by the Covid-19 pandemic has resulted in a particularly severe impact on the mental health of students. This period of their lives, between adolescence and adulthood, is fraught with decisive issues: changes in familial relationships, self-reliance, involvement in romantic and erotic relationships, essential choices: profession, partner. For some students, we could add to the list mobility or exile when studies require it, as well as economic concerns. It is therefore a pivotal period, which for the most part is productive, but also one of great psychological vulnerability. This vulnerability was heightened by the isolation and disruption of their education. These were the most striking effects of the health crisis on students. BAPU FSEF Paris V's mission is to provide students with access to psychodynamic psychotherapy. The team had to adapt its protocols to the qualitative and quantitative changes in demand during the health crisis. We discuss these changes by illustrating them with a clinical example. The long-term effects of the crisis are also discussed.
Une journée d’hommage à Jean Jacquart (1928-1998) a réuni des témoignages sur le professeur et ses méthodes d’animation de la recherche locale et générale, mais également sur les sociétés savantes et ...leurs fédérations. Pour aller plus loin dans l’analyse, les réflexions de Florence Tamagne sur l’homosexualité et celles de Denis Pelletier sur le catholicisme des années 1950 contextualisent ces souvenirs. Le Congrès national des sociétés historiques et scientifiques rassemble chaque année universitaires, membres de sociétés savantes et jeunes chercheurs. Ce recueil est issu de travaux présentés lors du 146e Congrès sur le thème « Périphéries ».
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