General equations for small‐angle neutron scattering are derived for block copolymers in dilute solution. The effects of excluded volume and polydispersity are examined. The applicability of the method of variable contrast to such systems is discussed.
Silica-based bioactive glasses (SBG) hold great promise as bio-functional coatings of metallic endo-osseous implants, due to their osteoproductive potential, and, in the case of designed formulations, suitable mechanical properties and antibacterial efficacy. In the framework of this study, the FastOs®BG alkali-free SBG system (mol%: SiO2—38.49, CaO—36.07, P2O5—5.61, MgO—19.24, CaF2—0.59), with CuO (2 mol%) and Ga2O3 (3 mol%) antimicrobial agents, partially substituting in the parent system CaO and MgO, respectively, was used as source material for the fabrication of intentionally silica-enriched implant-type thin coatings (~600 nm) onto titanium (Ti) substrates by radio-frequency magnetron sputtering. The physico-chemical and mechanical characteristics, as well as the in vitro preliminary cytocompatibility and antibacterial performance of an alkali-free silica-rich bio-active glass coating designs was further explored. The films were smooth (RRMS < 1 nm) and hydrophilic (water contact angle of ~65°). The SBG coatings deposited from alkali-free copper-gallium co-doped FastOs®BG-derived exhibited improved wear performance, with the coatings eliciting a bonding strength value of ~53 MPa, Lc3 critical load value of ~4.9 N, hardness of ~6.1 GPa and an elastic modulus of ~127 GPa. The Cu and Ga co-doped SBG layers had excellent cytocompatibility, while reducing after 24 h the Staphylococcus aureus bacterial development with 4 orders of magnitude with respect to the control situations (i.e., nutritive broth and Ti substrate). Thereby, such SBG constructs could pave the road towards high-performance bio-functional coatings with excellent mechanical properties and enhanced biological features (e.g., by coupling cytocompatibility with antimicrobial properties), which are in great demand nowadays.
The variable‐contrast method in small‐angle neutron scattering has been applied to a study of the conformation of polystyrene–polyisoprene block copolymers in dilute solution. The experimental results reveal no intramolecular segregation effect in dilute solutions in toluene and cyclohexane.
"Abstract: All large armies (EU and/or NATO) have pharmaceutical production facilities to provide the necessary antidotes for the troops and the population: The French Army Medical Directorate produces many military-specific pharmaceutical products in its own laboratory, the Turkish Army owns its own medicines factory, including CBRN antidotes, the US Army, in addition to a sustained drug purchase program in the pharmaceutical industry has launched a new concept: Pharmacy on demand. Providing the armed forces with antidotes is a necessity, the concept for their endowement in this sense can be based on imports (sometimes impossible to achieve) or on the national development of a specialized production structure. The design or construction of a specific production capacity for antidotes can be accomplished on multiple variants, with a complexity proportional to the identified need. The total costs are high, but the objective and implementation of effective antidote supply mechanisms is a security guarantee for the armed forces and the civilian population (through commercialization to allied forces), given the risks of terrorist threats and hybrid warfare. Keywords: medical protection, antidote, production, technological platform, medical countermeasures, pharmaceutical technique, orphan drug production "
Light scattering measurements from aqueous solutions for two samples of poly(acry1amideco-maleic anhydride) in the presence of salt are conducted. One of the samples exhibits a negative initial slope and a minimum in the plot of the conventional reciprocal scattered intensity function of sin2(O/2). The explanation for this anomaly is a large optical anisotropy of the segment. A correction for this effect of segmental anisotropy is made. The behaviour of the other sample of this copolymer is typical for a polyelectrolyte. By analysing the disymmetry of the scattered light, the influence of the salt concentration on the polyion is evidenced by the determination of the macromolecular dimensions. Light scattering data allow the evaluation of the Mark-Kuhn-Houwink exponent a for various degrees of dissociation of the polyion; a correlation between the variation of a and the shape of the macromolecule is observed.
The biological agent most likely to be used as a biological weapon is Bacillus anthracis, which causes the anthrax infectious disease. During the Cold War, it was present in large quantities in the military arsenals of some states, and at the beginning of the 21st century was used in a series of small bioterrorist attacks. In case of occurrence of events using Bacillus anthracis, urgent and adequate qualitative and quantitative response measures are needed to manage the consequences of the attack and to reduce the effects on public health. These include complex and well-coordinated activities to ensure medical intervention for the prophylaxis, treatment and recovery of patients. General prophylaxis is achieved by vaccination, individual and collective CBRN protection, decontamination, partial and total sanitary treatment, microbiological analysis for the detection, identification and confirmation of the biological agent. Therapy for disease induced by weaponized B. anthracis differs from classic antrax disease regarding antibiotics, doses and time, resulting a large antibiotic consumption per case. Complete recovery of the patients is achieved not only in terms of restoring normal biological parameters, but also in terms of the organism’s "sterilisation" regarding the causal biological agent.
One year after the beginning of the Covid-19 pandemic, on the world graph of daily morbidity can be seen that we are in the downturn of the third epidemic wave, consistent with the downturn of the third wave of daily deaths from/with Covid-19. However, the written press and the audiovisual media continue to present alarming balance sheets several times a day that lead the public to the idea of public danger. Doubts about the adequacy of declaring the pandemic were interpreted by some "naysayers" as doubts about the existence of the disease and the virus, and some loudly expressed their opposition against the prophylactic measures. Increasingly, public opinion, the press, and the judiciary system are shedding light on the causes of these approaches, which claim to be based on scientific criteria but sometimes prove to be pseudo-scientific, causing an „infodemic”. The best objective orientation in this informational chaos is based on the mathematical-statistical processing of official data that is centralized daily from all countries of the world and published on the Internet. The statistical calculation suggests that in addition to the inequalities inherent in different populations, there are also cases of over-reporting, overdiagnosis, over-treatment, and/or over-media coverage of the Covid-19 case practice. As a general conclusion, the virus is real, the disease is real, but the risk to public health is not particularly serious except in certain geographical areas. If scientifically established prophylaxis and treatment measures are followed, the pandemic may end this year.
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