Ionic and Polyampholyte N-Isopropylacrylamide-Based Hydrogels Prepared in the Presence of Imprinting Ligands: Stimuli-Responsiveness and Adsorption/Release Properties

The conformation of the imprinted pockets in stimulus-responsive networks can be notably altered when the stimulus causes a volume phase transition. Such a tunable affinity for the template molecule finds interesting applications in the biomedical and drug delivery fields. Nevertheless, the effect that the binding of the template causes on the stimuli-responsiveness of the network has barely been evaluated. In this work, the effect of two ionic drugs used as templates, namely propranolol hydrochloride and ibuprofen sodium, on the responsiveness of N-isopropylacrylamide-based hydrogels copolymerized with acrylic acid (AAc) and N-(3-aminopropyl) methacrylamide (APMA) and on their ability to rebind and to control the release of the template was evaluated. The degree of swelling and, in some cases, energetics (HS-DSC) of the transitions were monitored as a function of temperature, pH, and concentration of drug. Marked decrease in the transition temperature of the hydrogels, accompanied by notable changes in the transition width, was observed in physiological NaCl solutions and after the binding of the drug molecules, which reveals relevant changes in the domain structure of the hydrogels as the charged groups are shielded. The ability of the hydrogels to rebind propranolol or ibuprofen was quantified at both 4 and 37 °C and at two different drug concentrations, in the range of those that cause major changes in the network structure. Noticeable differences between hydrogels bearing AAc or APMA and between imprinted and non-imprinted networks were also observed during the release tests in NaCl solutions of various concentrations. Overall, the results obtained evidence the remarkable effect of the template molecules on the responsiveness of intelligent imprinted hydrogelsThis work was financed by Ministerio de Ciencia y Tecnología (SAF2011-22771 and MIPFOOD IPT-060000-2010-14) and FEDER Spain, and by the RFBR (Project 04-03-32355) and DCMS RAS (Program “Creation and Study of Macromolecules and Macromolecular Structures of New Generations”)S

Weakly-nonlocal Symplectic Structures, Whitham method, and weakly-nonlocal Symplectic Structures of Hydrodynamic Type

We consider the special type of the field-theoretical Symplectic structures called weakly nonlocal. The structures of this type are in particular very common for the integrable systems like KdV or NLS. We introduce here the special class of the weakly nonlocal Symplectic structures which we call the weakly nonlocal Symplectic structures of Hydrodynamic Type. We investigate then the connection of such structures with the Whitham averaging method and propose the procedure of "averaging" of the weakly nonlocal Symplectic structures. The averaging procedure gives the weakly nonlocal Symplectic Structure of Hydrodynamic Type for the corresponding Whitham system. The procedure gives also the "action variables" corresponding to the wave numbers of $m$-phase solutions of initial system which give the additional conservation laws for the Whitham system.Comment: 64 pages, Late

Phase behaviour of charged colloidal sphere dispersions with added polymer chains

We study the stability of mixtures of highly screened repulsive charged spheres and non-adsorbing ideal polymer chains in a common solvent using free volume theory. The effective interaction between charged colloids in an aqueous salt solution is described by a screened-Coulomb pair potential, which supplements the pure hard-sphere interaction. The ideal polymer chains are treated as spheres that are excluded from the colloids by a hard-core interaction, whereas the interaction between two ideal chains is set to zero. In addition, we investigate the phase behaviour of charged colloid-polymer mixtures in computer simulations, using the two-body (Asakura-Oosawa pair potential) approximation to the effective one-component Hamiltonian of the charged colloids. Both our results obtained from simulations and from free volume theory show similar trends. We find that the screened-Coulomb repulsion counteracts the effect of the effective polymer-mediated attraction. For mixtures of small polymers and relatively large charged colloidal spheres, the fluid-crystal transition shifts to significantly larger polymer concentrations with increasing range of the screened-Coulomb repulsion. For relatively large polymers, the effect of the screened-Coulomb repulsion is weaker. The resulting fluid-fluid binodal is only slightly shifted towards larger polymer concentrations upon increasing the range of the screened-Coulomb repulsion. In conclusion, our results show that the miscibility of dispersions containing charged colloids and neutral non-adsorbing polymers increases, upon increasing the range of the screened-Coulomb repulsion, or upon lowering the salt concentration, especially when the polymers are small compared to the colloids.Comment: 25 pages,13 figures, accepted for publication on J.Phys.:Condens. Matte

Cases of tuberculosis with lethal outcome among children: clinical epidemiological data

There is the comparative clinical epidemiological analysis of 54 cases of death of children with tuberculosis in Yekaterinburg and Sverdlovskaya oblast from 1977 to 2010. The aim of the research is to reveal epidemiological, social, clinical and immunological features of the children died of tuberculosis. The most of dead are prematurely born children who get artificial feeding; boys at the age of 1 - 3 injected with off-graded vaccine or not injected BCG at all; children from asocial families who have early and long-time contact with people discharging bacteria. The research shows that in the most cases with lethal outcome children didn't get proper treatment because of late diagnostics of a specific process; in some of the cases it was caused with polymorphic clinical finding, quick generalization of the process and progress of meningoencephalitis. The reason of death of 4 of the children with primary immunodeficiency is generalized BCG disease.Приведен сравнительный клинико-эпидемиологический анализ 54 случаев смерти детей больных туберкулезом в г. Екатеринбурге и Свердловской области за период с 1977 по 2010 гг. Цель исследования: выявить эпидемиологические, социальные, клинические, иммунологические особенности у умерших от туберкулеза детей. Среди умерших преобладали недоношенные дети, находившиеся на искусственном вскармливании, мальчики от 1 до 3 лет, не качественно вакцинированные или не привитые против туберкулеза, из асоциальных семей, имеющие ранний и длительный контакт с бактериовыделителями. Показано, что в большинстве летальных случаев туберкулеза дети не получали адекватного лечения из-за поздней диагностики специфического процесса, что в части случаев было обусловлено полиморфностью клинической картины, быстрой генерализацией процесса с развитием менингознцефалита. У 4 детей с первичными иммунодефицитами причиной смерти явилась генерализованная БЦЖ-инфекция

Population of isomers in decay of the giant dipole resonance

The value of an isomeric ratio (IR) in N=81 isotones ($^{137}$Ba, $^{139}$Ce, $^{141}$Nd and $^{143}$Sm) is studied by means of the ($\gamma, n)$ reaction. This quantity measures a probability to populate the isomeric state in respect to the ground state population. In ($\gamma, n)$ reactions, the giant dipole resonance (GDR) is excited and after its decay by a neutron emission, the nucleus has an excitation energy of a few MeV. The forthcoming $\gamma$ decay by direct or cascade transitions deexcites the nucleus into an isomeric or ground state. It has been observed experimentally that the IR for $^{137}$Ba and $^{139}$Ce equals about 0.13 while in two heavier isotones it is even less than half the size. To explain this effect, the structure of the excited states in the energy region up to 6.5 MeV has been calculated within the Quasiparticle Phonon Model. Many states are found connected to the ground and isomeric states by $E1$, $E2$ and $M1$ transitions. The single-particle component of the wave function is responsible for the large values of the transitions. The calculated value of the isomeric ratio is in very good agreement with the experimental data for all isotones. A slightly different value of maximum energy with which the nuclei rest after neutron decay of the GDR is responsible for the reported effect of the A-dependence of the IR.Comment: 16 pages, 4 Fig

Early indicators of exposure to biological threat agents using host gene profiles in peripheral blood mononuclear cells

<p>Abstract</p> <p>Background</p> <p>Effective prophylaxis and treatment for infections caused by biological threat agents (BTA) rely upon early diagnosis and rapid initiation of therapy. Most methods for identifying pathogens in body fluids and tissues require that the pathogen proliferate to detectable and dangerous levels, thereby delaying diagnosis and treatment, especially during the prelatent stages when symptoms for most BTA are indistinguishable flu-like signs.</p> <p>Methods</p> <p>To detect exposures to the various pathogens more rapidly, especially during these early stages, we evaluated a suite of host responses to biological threat agents using global gene expression profiling on complementary DNA arrays.</p> <p>Results</p> <p>We found that certain gene expression patterns were unique to each pathogen and that other gene changes occurred in response to multiple agents, perhaps relating to the eventual course of illness. Nonhuman primates were exposed to some pathogens and the <it>in vitro</it> and <it>in vivo</it> findings were compared. We found major gene expression changes at the earliest times tested post exposure to aerosolized <it>B. anthracis </it>spores and 30 min post exposure to a bacterial toxin.</p> <p>Conclusion</p> <p>Host gene expression patterns have the potential to serve as diagnostic markers or predict the course of impending illness and may lead to new stage-appropriate therapeutic strategies to ameliorate the devastating effects of exposure to biothreat agents.</p

Anthroponotic transmission of Cryptosporidium parvum predominates in countries with poorer sanitation - a systematic review and meta-analysis

Background: Globally cryptosporidiosis is one of the commonest causes of mortality in children under 24 months old and may be associated with important longterm health effects. Whilst most strains of Cryptosporidium parvum are zoonotic, C. parvum IIc is almost certainly anthroponotic. The global distribution of this potentially important emerging infection is not clear. Methods: We conducted a systematic review of papers identifying the subtype distribution of C. parvum infections globally. We searched PubMed and Scopus using the following key terms Cryptospor* AND parvum AND (genotyp* OR subtyp* OR gp60). Studies were eligible for inclusion if they had found C. parvum within their human study population and had subtyped some or all of these samples using standard gp60 subtyping. Pooled analyses of the proportion of strains being of the IIc subtype were determined using StatsDirect. Meta-regression analyses were run to determine any association between the relative prevalence of IIc and Gross Domestic Product, proportion of the population with access to improved drinking water and improved sanitation. Results: From an initial 843 studies, 85 were included in further analysis. Cryptosporidium parvum IIc was found in 43 of these 85 studies. Across all studies the pooled estimate of relative prevalence of IIc was 19.0% (95% CI: 12.9–25.9%), but there was substantial heterogeneity. In a meta-regression analysis, the relative proportion of all C. parvum infections being IIc decreased as the percentage of the population with access to improved sanitation increased and was some 3.4 times higher in those studies focussing on HIV-positive indivduals. Conclusions: The anthroponotic C. parvum IIc predominates primarily in lower-income countries with poor sanitation and in HIV-positive individuals. Given the apparent enhanced post-infectious virulence of the other main anthroponotic species of Cryptosporidium (C. hominis), it is important to learn about the impact of this subtype on human health

Anthroponotic transmission of Cryptosporidium parvum predominates in countries with poorer sanitation - a systematic review and meta-analysis

Background: Globally cryptosporidiosis is one of the commonest causes of mortality in children under 24 months old and may be associated with important longterm health effects. Whilst most strains of Cryptosporidium parvum are zoonotic, C. parvum IIc is almost certainly anthroponotic. The global distribution of this potentially important emerging infection is not clear. Methods: We conducted a systematic review of papers identifying the subtype distribution of C. parvum infections globally. We searched PubMed and Scopus using the following key terms Cryptospor* AND parvum AND (genotyp* OR subtyp* OR gp60). Studies were eligible for inclusion if they had found C. parvum within their human study population and had subtyped some or all of these samples using standard gp60 subtyping. Pooled analyses of the proportion of strains being of the IIc subtype were determined using StatsDirect. Meta-regression analyses were run to determine any association between the relative prevalence of IIc and Gross Domestic Product, proportion of the population with access to improved drinking water and improved sanitation. Results: From an initial 843 studies, 85 were included in further analysis. Cryptosporidium parvum IIc was found in 43 of these 85 studies. Across all studies the pooled estimate of relative prevalence of IIc was 19.0% (95% CI: 12.9–25.9%), but there was substantial heterogeneity. In a meta-regression analysis, the relative proportion of all C. parvum infections being IIc decreased as the percentage of the population with access to improved sanitation increased and was some 3.4 times higher in those studies focussing on HIV-positive indivduals. Conclusions: The anthroponotic C. parvum IIc predominates primarily in lower-income countries with poor sanitation and in HIV-positive individuals. Given the apparent enhanced post-infectious virulence of the other main anthroponotic species of Cryptosporidium (C. hominis), it is important to learn about the impact of this subtype on human health

Acute psychoses in reanimation period of acute myocardial infarction treatment

Aim. To study dynamics of acute psychosis (АР) incidence and clinical features during reanimation period of acute myocardial infarction (AMI) treatment, according to ten-year data from a large specialized Cardiology Center. Material and methods. The study was based on the case history data of all AMI patients, treated at Reanimation and Emergency Care Department, Yekaterinburg Clinical Center «Cardiology» (YeCCC), in 1995-2004 (in total, 12 048 case histories). From these data, 473 histories were selected, with AP registered during reanimation period of AMI treatment. Results. In 10 years, AP incidence increased from 1.57% to 5.65%. AP was registered significantly more often in AMI patients aged over 60 years. Myocardial damage severity determined AP development in reanimation period of AMI treatment. There was a significant positive correlation between AP in reanimation period of AMI treatment and lethality, regardless of age and AMI size. Conclusion. A non-precedent (by data volume and, therefore, by observed correlations and differences' significance) study of AP development in reanimation period of AMI treatment, based on 10-year data from one of the largest Russian Cardiology Centers, was performed. The results point to the problem's actuality in modern cardiology practice, and to a need for timely AP diagnostics, prevention and therapy during reanimation period of AMI treatment

The structure of j/i-hybrid carrageenans II. Coil–helix transition as a function of chain composition

This paper describes the effect of the k/i-ratio on the physical properties of k/i-hybrid carrageenans (synonyms: kappa-2, k-2, weak kappa, weak gelling kappa). To this end, a series of k/i-hybrid carrageenans ranging from almost homopolymeric k-carrageenan (98 mol% k-units) to almost homopolymeric-carrageenan (99 mol% i-units) have been extracted from selected species of marine red algae (Rhodophyta). The k/i-ratio of these k/i-hybrids was determined by NMR spectroscopy. Their rheological properties were determined by small deformation oscillatory rheology. The gel strength (storage modulus, G0) of the j/i-hybrids decreases with decreasing j-content. On the other hand, the gelation temperature of the k-rich k/i-hybrids is independent of their composition. This allows one to control the gel strength independent of the gelation or melting temperature. The conformational order–disorder transition of the k/i-hybrids was studied using optical rotation and high-sensitivity differential scanning calorimetry. High-sensitivity DSC showed that the total transition enthalpy of the k/i-hybrids goes through a minimum at 60 mol% k-units, whereas for the mixture of j- and i-carrageenan, the total transition enthalpy is a linear function of the composition. With respect to the ordering capability, the k/i-hybrid carrageenans seem to behave as random block copolymers with length sequence distributions truncated from the side of the small lengths. Intrinsic thermodynamic properties (e.g., transition temperature and enthalpy) of k- and i-sequences in these copolymers are close to those of their parent homopolymers. The critical sequence length for k-sequences is 2-fold of that for i-sequences