Supercritical fluid (SCF) technology has become an important tool of materials processing in the last two decades. Supercritical CO
2 and H
2O are extensively being used in the preparation of a great ...variety of nanomaterials. The greatest requirement in the application of nanomaterials is its size and morphology control, which determine the application potential of the nanoparticles, as their properties vary significantly with size. Although significance of SCF technology has been described earlier by various authors, the importance of this technology for the fabrication of inorganic and hybrid nanomaterials in biomedical applications has not been discussed thoroughly. This review presents the nanomaterial preparation systematically using SCF technology with reference to the processing of biomedical materials. The basic principles of each one of the processes have been described in detail giving their merits and perspectives. The actual experimental data and results have been discussed in detail with respect to the selected nanomaterials for biomedical applications. The SCF synthesis of nanoparticles like phosphors, magnetic materials, carbon nanotubes, etc. have been discussed as they have potential applications in bio-imaging, hyperthermia, cancer therapy, neutron capture therapy, targeted drug delivery systems and so on. The more recent approach towards the
in situ surface modification, dispersibility, single nanocrystal formation, and morphology control of the nanoparticles has been discussed in detail.
Control of the morphology of ceria nanocrystals is achieved through a simple, rapid, and green chemistry approach by tuning the reaction of organic ligand molecules with specific crystallographic ...planes of fluorite cubic ceria crystal during supercritical hydrothermal synthesis, as shown in the figure. It provides a novel self‐assembly approach for producing metal oxide nanocrystals with uniform size and well‐defined shape.
We report electrical resistivity, ac magnetic susceptibility, and x-ray absorption spectroscopy measurements of intermediate valence YbNi3Ga9 under pressure and magnetic field. We have revealed a ...characteristic pressure-induced Yb valence crossover within the temperature-pressure phase diagram, and a first-order metamagnetic transition is found below Pc~9 GPa where the system undergoes a pressure-induced antiferromagnetic transition. As a possible origin of the metamagnetic behavior, a critical valence fluctuation emerging near the critical point of the first-order valence transition is discussed on the basis of the temperature-field-pressure phase diagram.
In order to promote atom efficiency in synthesis and to avoid the generation of environmental waste, the use of stoichiometric amounts of condensing reagents or excess substrates should be avoided. ...In esterification, excesses of either carboxylic acids or alcohols are normally needed. We show that the direct condensation of equimolar amounts of carboxylic acids and alcohols can be achieved with the use of hafnium(IV) salts, such as commercially available hafnium(IV) chloride and hafnium(IV) tert-butoxide. The present method can be applied to direct polyesterification and may be suitable for large-scale operations.
We have succeeded in synthesizing the single crystal of R2Pt6Ga15 (R=La-Nd, Sm- Lu) with hexagonal Sc0.67Fe2Si5-type structure using Ga self flux method. The crystal structure was confirmed by the ...powder X-ray method. The unit-cell volume V of R2Pt6Ga15 follows the lanthanide concentration except R = Ce, Eu and Yb, indicating that the valences of R = La, Pr, Nd, Sm, Gd-Tm, and Lu ion are trivalent, whereas those of R = Ce, Eu and Yb ion are deviate from trivalent. We have measured the specific heat C(T) of R2Pt6Ga15. It is found that the magnetic order takes place in R2Pt6Ga15 (R=Pr, Nd, Sm-Tm). Moreover, the multiple phase transitions were observed in R2Pt6Ga15 (R = Nd, Eu, Gd and Ho).
Summary The purposes of this study were (i) to examine the relationship between the number of natural teeth and the number of functional tooth units in Japanese adults, (ii) to evaluate how ...functional tooth units relate to subjective masticatory ability and (iii) to determine the minimum number of natural teeth and functional tooth units needed to maintain adequate self‐assessed chewing function. A self‐administered questionnaire was given and dental examination was conducted for 2164 residents aged 40 to 75 years. Counts were made on the number of functional tooth units of natural teeth (n‐functional tooth units), the sum of natural teeth and artificial teeth on implant‐supported and fixed prostheses (nif‐functional tooth units) and the sum of natural teeth and artificial teeth on implant‐supported, fixed and removable prostheses (total‐functional tooth units). The average number of natural teeth, n‐functional tooth units and nif‐functional tooth units decreased with age, but these were often replaced by functional tooth units from artificial teeth on removable prostheses. Total‐functional tooth units in 50–59 year old people were slightly lower compared with those in other age groups. Subjects who reported that they could chew every food item on an average had 23·4 total natural teeth, 12·6 posterior natural teeth, 7·6 n‐functional tooth units, 8·6 nif‐functional tooth units and 10·4 total‐functional tooth units, and subjects without chewing difficulties had fewer functional tooth units from removable prostheses. Maintaining 20 and more natural teeth and at least eight nif‐functional tooth units is important in reducing the likelihood of self‐assessed chewing difficulties.
A peptide with an affinity for ZnO, selected by a phage‐display system, preferentially immobilizes ZnO particles on a gold‐coated polypropylene plate and assists in the homogeneous assembly of 10 nm ...diameter ZnO nanoparticles into unique flower‐like morphologies (see Figure). The peptide is selective in binding ZnO, but not ZnS or Eu2O3. This combinatorial library approach may yield new peptides used to create new structures via biomineralization.
Hospital-based patient portals have the potential to better inform and engage patients in their care. We sought to assess patients' and healthcare providers' perceptions of a hospital-based portal ...and identify opportunities for design enhancements.
We developed a mobile patient portal application including information about the care team, scheduled tests and procedures, and a list of active medications. Patients were offered use of tablet computers, with the portal application, during their hospitalization. We conducted semi-structured interviews of patients and provider focus groups. Text from transcribed interviews and focus groups was independently coded by two investigators using a constant comparative approach. Codes were reviewed by a third investigator and discrepancies resolved via consensus.
Overall, 18 patients completed semi-structured interviews and 21 providers participated in three focus groups. Patients found information provided by the portal to be useful, especially regarding team members and medications. Many patients described frequent use of games and non-clinical applications and felt the tablet helped them cope with their acute illness. Patients expressed a desire for additional detail about medications, test results, and the ability to record questions. Providers felt the portal improved patient engagement, but worried that additional features might result in a volume and complexity of information that could be overwhelming for patients. Providers also expressed concern over an enhanced portal's impact on patient-provider communication and workflow.
Optimizing a hospital-based patient portal will require attention to type, timing and format of information provided, as well as the impact on patient-provider communication and workflow.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Imaging studies indicate that experimental pain is processed in multiple cortical areas which are often characterized as a network. However, the functional connectivity within the network and the ...other properties of the network is poorly understood. Substantial evidence demonstrates that synchronous oscillations between two cortical areas may indicate functional connectivity between those areas. We test the hypothesis that cortical areas with pain-related activity are functionally connected during attention to a painful stimulus. We stimulated with a painful, cutaneous, laser stimulus and recorded the response directly from the cortical surface (electrocorticography – ECoG) over primary somatosensory (SI), parasylvian (PS), and medial frontal (MF) cortex through subdural electrodes implanted for treatment of epilepsy. The results demonstrate synchrony of ECoGs between cortical structures receiving input from nociceptors, as indicated by the occurrence of laser-evoked potentials (LEPs) and/or event-related desynchronization (ERD). Prior to the stimulus, directed attention to the painful stimulus consistently increased the degree of synchrony between SI and PS regions, as the subject anticipated the stimulus. After the laser stimulus, directed attention to the painful stimulus consistently increased the degree of synchrony between SI and MF cortex, as the subject responded by counting the stimulus. Therefore, attention to painful stimuli always enhanced synchrony between cortical pain-related structures. The pattern of this synchrony changed as the patient switched tasks from anticipation of the stimulus to counting the stimulus. These results are the first compelling evidence of pain networks characterized by rapidly switching, task-specific functional connectivity.
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