ABSTRACTGlobally the community of people with HIV is ageing, and some of these have increasingly complex care needs, with a known excess of non-HIV related comorbidities and related issues including consequent polypharmacy. At the 2022 International AIDS Conference in Montréal, Canada, the \"Silver Zone\" was created in the Global Village as a safe space for older people with HIV. As part of the Silver Zone activities, a session discussing global models of care for in this group was held. HIV treatment providers and advocates from diverse resource settings and with a diversity of expertise were invited to share their experience, reflections, and ideas, and this consensus statement was formed based on these discussions. Different approaches to care emerged, based on local needs and resources, and it became clear that issues of complexity and frailty need not be age limited. Despite clear regional differences, some common themes became apparent, and a consensus was established on basic principles that may be considered in diverse settings. These are discussed here, with agreement on necessary proximal steps to develop bespoke person-centred care models.

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Anisotropic metallic nanoparticles, such as Au and Ag nanoprisms (NPSMs), have received tremendous attention for their application in catalysis, molecular sensing, signal amplification, bioimaging, and therapeutic applications due to their shape-dependent optical and physical properties. Herein, we present a protein-enabled synthetic strategy for the seeded growth of silver and gold NPSMs with low shape polydispersity, narrow size distribution, and tailored plasmonic absorbance. During the initial seed nucleation step, consensus sequence tetratricopeptide repeat (CTPR) proteins are utilized as potent stabilizers to facilitate the formation of planar-twinned Ag seeds. High yield production of well-defined Ag/Au NPSMs is achieved, respectively, by adding CTPR-stabilized Ag seeds into the growth solutions containing metal precursor, mild reducing agent, sodium halide, and additional CTPR.

Regulatory ecotoxicity testing of chemicals is of societal importance and a large effort is undertaken at the OECD to ensure that OECD test guidelines (TGs) for nanomaterials (NMs) are available. Significant progress to support the adaptation of selected TGs to NMs was achieved in the context of the project MARINA ( http://www.marina-fp7.eu/ ) funded within the 7th European Framework Program. Eight OECD TGs were adapted based on the testing of at least one ion-releasing NM (Ag) and two inert NMs (TiO2). With the materials applied, two main variants of NMs (ion releasing vs. inert NMs) were addressed. As the modifications of the test guidelines refer to general test topics (e.g. test duration or measuring principle), we assume that the described approaches and modifications will be suitable for the testing of further NMs with other chemical compositions. Firm proposals for modification of protocols with scientific justification(s) are presented for the following tests: growth inhibition using the green algae Raphidocelis subcapitata (formerly: Pseudokirchneriella subcapitata; TG 201), acute toxicity with the crustacean Daphnia magna (TG 202), development toxicity with the fish Danio rerio (TG 210), reproduction of the sediment-living worm Lumbriculus variegatus (TG 225), activity of soil microflora (TGs 216, 217), and reproduction of the invertebrates (Enchytraeus crypticus, Eisenia fetida, TGs 220, 222). Additionally, test descriptions for two further test systems (root elongation of plants in hydroponic culture; test on fish cells) are presented. Ecotoxicological data obtained with the modified test guidelines for TiO2 NMs and Ag NM and detailed method descriptions are available.

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In aquatic toxicity testing of engineered nanoparticles (ENPs) the process of agglomeration is very important as it may alter bioavailability and toxicity. In the present study, we aimed to identify test conditions that are favorable for maintaining stable ENP suspensions. We evaluated the influence of key environmental parameters: pH (2-12) and ionic strength using M7, Soft EPA (S EPA) medium, and Very Soft EPA (VS EPA) medium; and observed the influence of these parameters on zeta potential, zeta average, and acute immobilization of Daphnia magna for three different ENPs. Despite being sterically stabilized, test suspensions of silver (Ag) ENPs formed large agglomerates in both VS EPA and M7 media; and toxicity was found to be higher in VS EPA medium due to increased dissolution. Low-agglomerate suspensions for zinc oxide (ZnO) could be obtained at pH 7 in VS EPA medium, but the increase in dissolution caused higher toxicity than in M7 medium. Titanium dioxide (TiO2) ENPs had a point of zero charge in the range of pH 7-8. At pH 7 in VS EPA, agglomerates with smaller hydrodynamic diameters (~200nm) were present compared to the high ionic strength M7 medium where hydrodynamic diameters reached micrometer range. The stable suspensions of TiO2 ENPs caused immobilization of D. magna, 48-h EC50 value of 13.7mgL(-1) (95% CI, 2.4mg-79.1mgL(-1)); whereas no toxicity was seen in the unstable, highly agglomerated M7 medium suspensions, 48-h EC50 >100mgL(-1). The current study provides a preliminary approach for methodology in testing and assessing stability and toxicity of ENPs in aquatic toxicity tests of regulatory relevance.

The present study investigated changes in suspension stability and ecotoxicity of engineered nanoparticles (ENPs) by addition of Suwannee River natural organic matter and aging of stock and test suspensions prior to testing. Acute toxicity tests of silver (Ag), zinc oxide (ZnO), and titanium dioxide (TiO2 ) ENPs with Daphnia magna were carried out following Organisation for Economic Co-operation and Development test guidelines. Daphnia magna was found to be very sensitive to Ag ENPs (48-h 50% effective concentration 33 μg L(-1) ), and aging of the test suspensions in M7 medium (up to 48 h) did not decrease toxicity significantly. Conversely, the presence of Suwannee River natural organic matter (NOM; 20 mg L(-1) ) completely alleviated Ag ENP toxicity in all testing scenarios and did not aid in stabilizing suspensions. In contrast, addition of Suwannee River NOM stabilized ZnO ENP suspensions and did not decrease toxicity. Aging for 48 h generated monotonous concentration-response curves in the presence and absence of Suwannee River NOM. At concentrations up to 100 mg L(-1) TiO2 ENPs did not cause immobilization of D. magna under any of the tested conditions. Presence of Suwannee River NOM caused agglomeration in stock suspensions. The authors\' results suggest that aging and presence of Suwannee River NOM are important parameters in standard toxicity testing of ENPs, which in some cases may aid in gaining better control over the exposure conditions but in other cases might contribute to agglomeration or elimination of ENP toxicity. Therefore, modifications to the current guidelines for testing ENPs should be evaluated on a case-by-case basis. Environ Toxicol Chem 2015;34:497-506. © 2014 SETAC.

Despite the current advancement in drug discovery and pharmaceutical biotechnology, infection diseases induced by bacteria continue to be one of the greatest health problems worldwide, afflicting millions of people annually. Almost all microorganisms have, in fact, an intrinsic outstanding ability to flout many therapeutic interventions, thanks to their fast and easy-to-occur evolutionary genetic mechanisms. At the same time, big pharmaceutical companies are losing interest in new antibiotics development, shifting their capital investments in much more profitable research and development fields. New smart solutions are, thus, required to overcome such concerns, and should combine the feasibility of industrial production processes with cheapness and effectiveness. In this framework, nanotechnology-based solutions, and in particular silver nanoparticles (AgNPs), have recently emerged as promising candidates in the market as new antibacterial agents. AgNPs display, in fact, enhanced broad-range antibacterial/antiviral properties, and their synthesis procedures are quite cost effective. However, despite their increasing impact on the market, many relevant issues are still open. These include the molecular mechanisms governing the AgNPs-bacteria interactions, the physico-chemical parameters underlying their toxicity to prokaryotes, the lack of standardized methods and materials, and the uncertainty in the definition of general strategies to develop smart antibacterial drugs and devices based on nanosilver. In this review, we analyze the experimental data on the bactericidal effects of AgNPs, discussing the complex scenario and presenting the potential drawbacks and limitations in the techniques and methods employed. Moreover, after analyzing in depth the main mechanisms involved, we provide some general strategies/procedures to perform antibacterial tests of AgNPs, and propose some general guidelines for the design of antibacterial nanosystems and devices based on silver/nanosilver.

The finite element method is used to simulate light absorption in periodic hybrid Si nanohole (SiNH)/PEDOT:PSS arrays. The structural periodicity (P) and hole diameter (D) of the hybrid SiNH structure are varied to maximize light absorption. In terms of the solar cell performance under the AM1.5G spectrum, the highest ultimate efficiency achieved is 30.5%, when the D/P ratio is 0.8 and P is 600 nm. We have successfully fabricated the SiNH structure based on a low cost electroless chemical etching approach using a silver catalyst. The SiNH diameters formed vary from ∼200 to 300 nm, with periodicities from ∼300 to 1000 nm. The SiNH structure reveals a low average reflectance of 4% for incident light in the range 300 to 1100 nm.

Nanometals are manufactured to particle sizes with diameters in the nanometer range and are included in a variety of consumer and health products. There is a lack of information regarding potential effects of these materials on aquatic organisms. Amphibians are regarded as environmental sentinels and demonstrate an exquisite sensitivity to thyroid hormone action, a hormone that is essential for human health. This present study assessed the effect of exposure to nanometals on stress and thyroid hormone signaling in frog tissue using a cultured tail fin biopsy (C-fin) assay derived from Rana catesbeiana tadpoles. The C-fin assay maintains tissue complexity and biological replication while multiple chemical responses can be assessed from the same individual. We tested the ability of nanosilver (0.06 μg/L-5.5 mg/L), quantum dots (0.25 μg/L-22 mg/L), and nanozinc oxide (0.19-10 mg/L) to alter gene expression in the presence or absence of 3,3\',5\'-triiodothyronine (T(3)) using quantitative real-time polymerase chain reaction. Results were compared to exposure to micrometer-silver, silver nitrate, and micrometer-cadmium telluride. Nanosilver (≥2.75 mg/L) and quantum dots (≥0.22 mg/L) altered the expression of transcripts linked to T(3)- and stress-mediated pathways, while nanozinc oxide had no effect. Lower concentrations of nanosilver (0.6 to 550 μg/L) perturbed T(3)-mediated signaling while not inducing cell stress. The observed effects were orders of magnitude below acute toxicity levels and occurred at or below the current North American water quality guidelines for metals, underscoring the need for evaluating nanoparticles separately from their constituent chemicals.