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A new type of silver nanoparticles (AgNPs) was prepared and comprehensively studied. Scanning electron microscopy (SEM) and dynamic light scattering (DLS) analyses indicated that 24 nm AgNPs with narrow size distribution were obtained while Z-potential confirms their good stability. The composites of the obtained AgNPs with nontoxic-nature-inspired hydrogel were formed upon cooling of the aqueous solution AgNPs and C 12 Ala. The thermal gravimetric analysis (TGA) and the differential scanning calorimetry (DSC) do not show significant shifts in the characteristic temperature peaks for pure and silver-enriched gels, which indicates that AgNPs do not strongly interact with C 12 Ala fibers, which was also confirmed by SEM. Both AgNPs alone and in the assembly with the gelator C 12 Ala were almost biologically passive against bacteria, fungus, cancer, and nontumor human cells, as well as zebra-fish embryos. These studies proved that the new inactive AgNPs-doped hydrogels have potential for the application in therapy as drug delivery media.

An aqueous solution of sodium citrate stabilized gold nanoparticles (AuNP) in the presence of N- lauroyl-L-alanine (C 12 ALA) forms a stable gel. The structure of the gel and the distribution profile of AuNP in it were analyzed. Will nanoparticles separated from each other with sodium citrate behave in the same way in solution and trapped in the gel matrix? Will the spatial limitation of solvent molecules aggregate nanoparticles and destroy their homogeneity? These questions are very important from the point of view of the use of gold nanoparticles, trapped in the gel structure as carriers of drugs in the slow-release process. The lack of homogeneity of this distribution will have a major impact on the rate of release of the appropriate amount of therapeutic drug from the matrix. In this work, we attempt to answer these questions. The performed biological assays revealed that both C 12 ALA and C 12 ALA-AuNP show an excellent level of biological neutrality. They might be used as a transporting medium for a drug delivery without affecting the drug's activity.

The mental health of doctors in training raises two major concerns, first that they are reluctant to, and have difficulty accessing, treatment, and second that undiagnosed and untreated doctors expose patients to unacceptable risks. Four 1-h focus groups were held, with participants' views explored on their observations about mental health as an issue amongst doctors, their personal knowledge of, and preferences for, sources of support, and other related factors. Transcripts were analysed using a thematic framework approach.

Supramolecular gels formed by the sugar gelator of methyl-4,6-O-(p-nitrobenzylidene)-α-d-glucopyranoside (1) with 1,3-propanediol (PG) and 1-butanol (BU) were prepared with different gelator concentrations. The solvent dynamics within gels, characterized by the diffusion coefficient (D) and the spin-lattice relaxation time (T1), was the subject of NMR diffusometry and relaxometry studies. The diffusion was studied as a function of diffusion time and gelator concentrations. The relaxation time was measured as a function of Larmor frequency. The decrease of the diffusion coefficient was observed as a function of diffusion time for both gels and for all studied gelator concentrations. It is indicative of the confinement effect due to the geometrical restrictions of the gel matrix. The relaxation data for PG solvent confined in 1/PG gel revealed the low frequency dispersion (in kHz region) which is a fingerprint of a specific interaction experienced by PG solvents in the presence of the rigid structure of gelator 1 aggregates. The relaxation model, well known from the interpretation of liquid confined in nanopores as reorientations mediated by translational displacements (RMTD), was successfully applied to analyze the data of studied solvents confined in matrices of supramolecular gels. The microstructures of gel matrices were imaged by Polarized Microscopy., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Organogels are soft materials consisting of low-molecular-mass gelators (LMOGs) self-assembled through noncovalent interactions into 3D structures, in which free spaces are filled by organic solvents. 4,6,4',6'-O-terephthylidene-bis(methyl-α-d-glucopyranoside) (1) is found to be a new LMOG. It gelatinizes only a limited number of solvents. Here, the gels of 1 with ethylene glycol (EG) and 1,3-propanediol (PG) are investigated with FT-IR, Raman, and UV-vis spectroscopies, the NMR relaxometry and diffusometry methods, and microscopic observation. The chemical structures of both solvents are closely related, but the variety of physical characteristics of the gels is large. The 1/PG gels are thermally more stable compared to 1/EG gels. The types of aggregates are most likely the H- and J-type in 1/EG gels and the J-type in 1/PG gels. Different microstructures are observed: bundles of crossing fibers for 1/EG and a honeycomb-like matrix for 1/PG gels. The diffusivity of the EG solvent in gels with 1 behaves as expected, decreasing with increasing gelator concentration, whereas the opposite behavior is observed for the PG solvent. This is a most fascinating result. To explain the diffusion enhancement, we suggest that a dynamic hydrogen bonding network of PG solvent in gel matrixes is disrupted due to solvent-gelator interaction. The direct proof of this interaction is given by the observed low frequency dispersion of the spin-lattice relaxation time of solvents in the gel matrixes.

The availability of digital stereoscopic video feedback on surgical robotic platforms allows for a variety of enhancements through the application of computer vision. Several of these enhancements, such as augmented reality and semi-automated surgery, benefit significantly from identification of the robotic manipulators within the field of view. A method is presented for the extraction of robotic manipulators from stereoscopic views of the operating field that uses a combination of marker tracking, inverse kinematics, and computer rendering. This method is shown to accurately identify the locations of the manipulators within the views. It is further demonstrated that this method can be used to enhance 3D reconstruction of the operating field and produce augmented views.

Background: Accurate real-time 3D models of the operating field have the potential to enable augmented reality for endoscopic surgery. A new system is proposed to create real-time 3D models of the operating field that uses a custom miniaturized stereoscopic video camera attached to a laparoscope and an image-based reconstruction algorithm implemented on a graphics processing unit (GPU)., Methods: The proposed system was evaluated in a porcine model that approximates the viewing conditions of in vivo surgery. To assess the quality of the models, a synthetic view of the operating field was produced by overlaying a color image on the reconstructed 3D model, and an image rendered from the 3D model was compared with a 2D image captured from the same view., Results: Experiments conducted with an object of known geometry demonstrate that the system produces 3D models accurate to within 1.5 mm., Conclusions: The ability to produce accurate real-time 3D models of the operating field is a significant advancement toward augmented reality in minimally invasive surgery. An imaging system with this capability will potentially transform surgery by helping novice and expert surgeons alike to delineate variance in internal anatomy accurately.

The paper presents the diffusive diffraction phenomenon observed by the single-pulse-gradient spin-echo (s-PGSE) NMR technique in a real porous material: a gel composed of low-molecular-mass gelator methyl-4,6-O-(p-nitrobenzylidene)-α-D-glucopyranoside and toluene. Thanks to this phenomenon, we can probe the true microstructure (not xerogel) in which the toluene diffuses. To analyze the measured diffusion-diffraction pattern, we employed a composite bicompartmental model that superimposes restricted diffusion in small cavities of the gel matrix within the bundles of crossing fibers, with free diffusion in large and unconfined compartments between the bundles of crossing fibers. For restricted diffusion a pore-hopping formalism was applied. The observation of the diffraction pattern and its analysis leads to the conclusion that the pores, in the slow diffusing compartment of studied gel are ordered, at least locally, and relatively monodisperse with a size of 64 μm. Moreover, the restricting walls formed by the crossing fibers are perpendicular to the direction of the diffusion gradient.

Robotic surgical platforms require vision feedback systems, which often consist of low-resolution, expensive, single-imager analog cameras. These systems are retooled for 3D display by simply doubling the cameras and outboard control units. Here, a fully-integrated digital stereoscopic video camera employing high-definition sensors and a class-compliant USB video interface is presented. This system can be used with low-cost PC hardware and consumer-level 3D displays for tele-medical surgical applications including military medical support, disaster relief, and space exploration.

Background: Population based genetics studies are dependent on large numbers of individuals in the pursuit of small effect sizes. Recruiting and consenting a large number of participants is both costly and time consuming. We explored whether an online consent process for large-scale genetics studies is acceptable for prospective participants using an example online genetics study., Methods: We conducted semi-structured interviews with 42 members of the public stratified by age group, gender and newspaper readership (a measure of social status). Respondents were asked to use a website designed to recruit for a large-scale genetic study. After using the website a semi-structured interview was conducted to explore opinions and any issues they would have. Responses were analysed using thematic content analysis., Results: The majority of respondents said they would take part in the research (32/42). Those who said they would decline to participate saw fewer benefits from the research, wanted more information and expressed a greater number of concerns about the study. Younger respondents had concerns over time commitment. Middle aged respondents were concerned about privacy and security. Older respondents were more altruistic in their motivation to participate. Common themes included trust in the authenticity of the website, security of personal data, curiosity about their own genetic profile, operational concerns and a desire for more information about the research., Conclusions: Online consent to large-scale genetic studies is likely to be acceptable to the public. The online consent process must establish trust quickly and effectively by asserting authenticity and credentials, and provide access to a range of information to suit different information preferences.

Magnetic resonance imaging (MRI) is a non-destructive and non-invasive method, the experiment can be conducted in situ and allows the studying of the sample and the different processes in vitro or in vivo. 1D, 2D or 3D imaging can be undertaken. MRI is nowadays most widely used in medicine as a clinical diagnostic tool, but has still seen limited application in the food and pharmaceutical sciences. The different imaging pulse sequences of MRI allow to image the processes that take place in a wide scale range from ms (dissolution of compact tablets) to hours (hydration of drug delivery systems) for mobile as well as for rigid spins, usually protons. The paper gives examples of MRI application of in vitro imaging of pharmaceutical dosage based on hydroxypropyl methylcellulose which have focused on water-penetration, diffusion, polymer swelling, and drug release, characterized with respect to other physical parameters such as pH and the molecular weight of polymer. Tetracycline hydrochloride was used as a model drug. NMR imaging of density distributions and fast kinetics of the dissolution behavior of compact tablets is presented for paracetamol tablets., (Copyright © 2010 Elsevier B.V. All rights reserved.)

Background: In health care, a well recognized gap exists between what we know should be done based on accumulated evidence and what we actually do in practice. A body of empirical literature shows organizations, like individuals, are difficult to change. In the business literature, knowledge management and transfer has become an established area of theory and practice, whilst in healthcare it is only starting to establish a firm footing. Knowledge has become a business resource, and knowledge management theorists and practitioners have examined how knowledge moves in organisations, how it is shared, and how the return on knowledge capital can be maximised to create competitive advantage. New models are being considered, and we wanted to explore the applicability of one of these conceptual models to the implementation of evidence-based practice in healthcare systems., Methods: The application of a conceptual model called sticky knowledge, based on an integration of communication theory and knowledge transfer milestones, into a scenario of attempting knowledge transfer in primary care., Results: We describe Szulanski's model, the empirical work he conducted, and illustrate its potential applicability with a hypothetical healthcare example based on improving palliative care services. We follow a doctor through two different posts and analyse aspects of knowledge transfer in different primary care settings. The factors included in the sticky knowledge model include: causal ambiguity, unproven knowledge, motivation of source, credibility of source, recipient motivation, recipient absorptive capacity, recipient retentive capacity, barren organisational context, and arduous relationship between source and recipient. We found that we could apply all these factors to the difficulty of implementing new knowledge into practice in primary care settings., Discussion: Szulanski argues that knowledge factors play a greater role in the success or failure of a knowledge transfer than has been suspected, and we consider that this conjecture requires further empirical work in healthcare settings.

The chain dynamics in methyl cellulose (MC), hydroxypropylmethyl cellulose (HPMC) and hydroxypropyl cellulose (HPC) were studied with the aid of field-cycling NMR relaxometry technique in the temperature range from 300 to 480 K that is above the glass transition, but below thermal degradation. The frequency dependence of proton spin-lattice relaxation time was determined between 24 kHz and 40 MHz for selected temperatures. The experimental spin-lattice relaxation dispersion data were fitted with the power law relations of T(1) proportional variant omega(gamma) predicted by the tube/reptation model. The exponent's values found from the fitting procedure for MC, HPMC and HPC almost exactly match the ones predicted in tube/reptation model for limit II (gamma=0.75) and in MC also for limit III (gamma=0.50). Remarkably, this finding concerns the polymers in networks formed of the same polymer species.

Magnetic resonance microscopy was used to study the interaction of an alkaline water solvent (pH=12) with hydroxypropylmethyl cellulose (HPMC) matrices with different molecular masses Mw=12,000, 86,000, and 120,000. The polymers in the form of cylinders were hydrated at 37 degrees C and monitored at equal time intervals with a 300MHz Bruker AVANCE. The spatially resolved spin-spin relaxations times T2 and diffusion coefficients D of the solvent molecules within the gel layer of HPMC samples, along with changes in the dimension of the glass core of the polymers were determined as a function of hydration times. The experimental data allows us to characterize the diffusion mechanism as being Fickian and to determine the mean diffusivity values D of the solvent molecules for each voxel within the gel of the studied polymers. The influence of the molecular mass of the HPMC polymers on swelling properties has been shown.

The authors analysed clinical picture and morphological (macroscopic and histopathologic) changes in gastric and duodenal mucosa in 150 children diagnosed with Helicobacter pylori infection chosen randomly among the hospitalized in 1998-2000 years.

In literature and clinical findings, the attention has been turned to the resistance to the antibiotics used in Helicobacter pylori eradication, especially metronidazole and clarithromycin. Drug-resistance was evaluated in 50 children. Primary drug-resistance to the antibiotics used in eradications was determined in this group, and additionally, in 18 children who were subjected twice to unsuccessful eradicative therapy. The highest secondary resistance to metronidazole up to 72.0% was found among conventionally used antibiotics. Primary resistance of H. pylori rods to clarithromycin was also high and equaled 25.0%. However, in our study secondary resistance to macrolides was about 66.0%. In our study combined primary resistance to clarithromycin and metronidazole was about 7.2%. There was not H. pylori rods resistance to amoxicillin and tetracyclines.

Magnetic resonance imaging was used to study the behavior of the gel layer thickness in hydroxypropyl methyl cellulose (HPMC) matrices loaded with different amounts of soluble tetracycline hydrochloride. The time dependence of the diffusion front, effective T2, and proton-density analysis clearly indicates a Case II diffusion mechanism in the system composed of water solution of hydrochloric acid (pH = 2) and HPMC. The solvent penetration front was used to describe the swelling properties as well as the integrity of the HPMC matrices. The results show that the tetracycline hydrochloride decreases the resistance of the HPMC network structure against the movement of solvent molecules. On the other hand the swelling properties of the matrix increase with the amount of drug in the matrix.

Magnetic resonance imaging was used to study the diffusion of a water solution of hydrochloric acid into hypromellose (hydroxypropylmethylcellulose) matrices. Spatially resolved information was obtained about the self-diffusion coefficient and spin-spin relaxation time of solvent protons in the gel layer of hypromellose matrices loaded with different amounts of tetracycline hydrochloride. The data showed the influence of the drug concentration on the diffusion and spin-spin relaxation. Higher drug concentrations in the hypromellose matrix led to greater swelling of the matrix and faster diffusion of the water molecules inside the gel layer of the polymer. The observed differences between the radial and axial diffusion were interpreted in terms of the stresses imposed in the axial direction during the compression of the samples. The spin-spin and diffusion profiles indicated that the diffusion of a water solution of hydrochloric acid into hypromellose, pure and loaded with different amounts of tetracycline hydrochloride, was characterized as a Case II mechanism.

Event-related brain potentials were recorded in two three-stimulus oddball tasks in 13 adult dyslexic and 13 age- and IQ-matched normal readers. The stimuli consisted of a random series of frequent (80%) and non-frequent tones (10%) as well as occasionally inserted novel sounds (10%). The experiment comprised an active (response to the rare target tone) and a passive listening condition. No performance differences were found for dyslexic and normal readers in the active task. In both conditions, novel sounds evoked a centrally distributed P3a-component followed by a P3b-component most prominent at parietal electrodes for target and novel sounds. Additionally, a slow negativity emerged after presentation of novel sounds at frontal electrodes. In the active condition only, peak amplitude of the P3a and the frontal slow negativity to novel stimuli were slightly enlarged for dyslexic readers. These findings indicate a larger distractability of dyslexic readers (enhancement of P3a to novel tones). Furthermore, we propose that dyslexics need to employ more cognitive resources to refocus on the task at hand (as indicated by the enlarged slow frontal negativity).

The disintegration behavior of paracetamol tablets was studied by magnetic resonance imaging (MRI) using the Snapshot FLASH method. The total time of the single experiment is 425 ms and allows the study of the disintegration process in real time. The study was carried out in vitro under acidic gastric pH conditions and may help to predict the behavior of paracetamol tablets in the stomach after oral administration. It was shown that in spite of identical conditions, the disintegration of the tablets under study was different. The distribution of protons of 4-(N-acetyl)aminophenol within the paracetamol tablet was shown to be homogeneous. The study was carried out in a non-destructive way by the SPI MRI method.

The serum concentrations of individual short-chain fatty acids containing 2-6 carbon atoms were studied in 12 underweight children. Mean n-butyric and iso-valeric acid levels were significantly elevated in underweight children, while those of n-valeric and iso-caproic acids were not significantly higher than in the control group. The level of total free fatty acids was also increased in the underweight group. A reduced enzymatic activity in fatty acid synthesis is supposed to be the factor underlying the impaired lipogenesis.