246 research outputs found
Chemical synthesis and magnetic properties of monodisperse cobalt ferrite nanoparticles
In this work, a successful synthesis of magnetic cobalt ferrite (CoFe2O4)
nanoparticles is presented. The synthesized CoFe2O4 nanoparticles have a
spherical shape and highly monodisperse in the selected solvent. The effect of
different reaction conditions such as temperature, reaction time and varying
capping agents on the phase and morphology is studied. Scanning transmission
electron microscopy showed that the size of these nanoparticles can be
controlled by varying reaction conditions. Both X-ray diffraction and energy
dispersive X-ray spectroscopy corroborate the formation of CoFe2O4 spinel
structure with cubic symmetry. Due to optimized reaction parameters, each
nanoparticle was shown to be a single magnetic domain with diameter ranges from
6 to 16 nm. Finally, the magnetic investigations showed that the obtained
nanoparticles are superparamagnetic with a small coercivity value of about 315
Oe and a saturation magnetization of 58 emu/g at room temperature. These
results make the cobalt ferrite nanoparticles promising for advanced magnetic
nanodevices and biomagnetic applications.Comment: 10 pages, 9 figure
WPA guidance on mental health and mental health care in migrants
The WPA is committed to promote equity in the access
to mental health services for persons of different age, gender,
race/ethnicity, religion and socioeconomic status. As
part of this commitment, the Association decided to devote
one of the guidances to be developed within its Action
Plan 2008-2011 (1,2) to mental health and mental
health care in migrants. A Task Force was appointed for
this purpose, which produced the present document.
Mental health practitioners work in an increasingly
multicultural world, shaped by the migrations of people of
many different cultural, racial and ethnic backgrounds.
People migrate for many reasons: political, socioeconomic
and educational. The diversity of cultures, ethnicity, races
and reasons for migration can make understanding experiences
of illness challenging in migrants whose background
differs significantly from the clinician.
Culture has an important role in the presentation of
distress and illness, and cultural differences impact upon
the diagnosis and treatment of migrant populations in
part due to linguistic, religious and social variation from
the clinician providing care. Additionally, it appears that
the incidence and prevalence of mental disorders varies
among people of different cultural backgrounds, due to an
interplay of biological, psychological and social factors.
The provision of health care is necessarily influenced by
the demands of people of many different cultures, and it
is important that cultural differences be appreciated and
understood to arrive at a correct diagnostic impression
and treatment plan
Pneumonia Recovery; Discrepancies in Perspectives of the Radiologist, Physician and Patient
The correlation of RNase A enzymatic activity with the changes in the distance between Nepsilon2-His12 and N delta1-His119 upon addition of stabilizing and destabilizing salts.
The effect of stabilizing and destabilizing salts on the catalytic behavior of ribonuclease A (RNase A) was investigated at pH 7.5 and 25 degrees C, using spectrophotometric, viscometric and molecular dynamic methods. The changes in the distance between N(epsilon2) of His(12) and N(delta1) of His(119) at the catalytic center of RNase A upon the addition of sodium sulfate, sodium hydrogen sulfate and sodium thiocyanate were evaluated by molecular dynamic methods. The compactness and expansion in terms of Stokes radius of RNase A upon the addition of sulfate ions as kosmotropic salts, and thiocyanate ion as a chaotropic salt, were estimated by viscometric measurements. Enzyme activity was measured using cytidine 2', 3'-cyclic monophosphate as a substrate. The results from the measurements of distances between N(epsilon2) of His(12) and N(delta1) of His(119) and Stokes radius suggest (i) that the presence of sulfate ions decreases the distance between the catalytic His residues and increases the globular compactness, and (ii) that there is an expansion of the enzyme surface as well as elongation of the catalytic center in the presence of thiocyanate ion. These findings are in agreement with activity measurements
Direct Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry Improves Appropriateness of Antibiotic Treatment of Bacteremia
Matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) allows the identification of microorganisms directly from positive blood culture broths. Use of the MALDI-TOF MS for rapid identification of microorganisms from blood culture broths can reduce the turnaround time to identification and may lead to earlier appropriate treatment of bacteremia. During February and April 2010, direct MALDI-TOF MS was routinely performed on all positive blood cultures. During December 2009 and March 2010 no direct MALDI-TOF MS was used. Information on antibiotic therapy was collected from the hospital and intensive care units' information systems from all positive blood cultures during the study period. In total, 253 episodes of bacteremia were included of which 89 during the intervention period and 164 during the control period. Direct performance of MALDI-TOF MS on positive blood culture broths reduced the time till species identification by 28.8-h and was associated with an 11.3% increase in the proportion of patients receiving appropriate antibiotic treatment 24 hours after blood culture positivity (64.0% in the control period versus 75.3% in the intervention period (p0.01)). Routine implementation of this technique increased the proportion of patients on adequate antimicrobial treatment within 24 hours
Comparison between a new multiplex electrochemiluminescence assay and the WHO reference enzyme-linked immunosorbent assay to measure serum antibodies against pneumococcal serotype-specific polysaccharides
BACKGROUND: Two electrochemiluminescence (ECL) assays were developed which, together, can simultaneously measure serum antibodies against pneumococcal capsular polysaccharides (PnPS) for 17 serotypes. The assays were validated for the 13 PnPS included in the 13-valent pneumococcal conjugate vaccine (PCV13). As recommended by the World Health Organization (WHO), we compared the ECL assays with the WHO reference enzyme-linked immunosorbent assay (ELISA) and derived a threshold corresponding to the 0.35 µg/mL threshold established for the WHO reference ELISA for the non-inferiority comparison and licensure of new PCVs against invasive pneumococcal disease. METHODS: A panel of 452 serum samples from children vaccinated with one of the three licensed PCVs was assessed with the ECL assays and the WHO reference ELISA. The ECL assay threshold for the aggregated seven PnPS included in the 7-valent PCV (PCV7) and serotype-specific thresholds were determined using a receiver operating characteristics (ROC) curve-based approach and Deming regression. To evaluate concordance between the ECL assays and the WHO reference ELISA, serostatus agreement rates between both assays and geometric means of the ratios (GMRs) of concentrations obtained with both assays were calculated. RESULTS: The thresholds for the seven aggregated PCV7 serotypes obtained with the ROC curve-based approach and Deming regression approximated 0.35 µg/mL (0.38 and 0.34 µg/mL, respectively). Individual thresholds for the PCV13 serotypes ranged between 0.24 and 0.51 µg/mL across both approaches. Serostatus agreement rates using a 0.35 µg/mL threshold for both assays were ≥86.9% for all PCV13 serotypes. GMRs ranged between 0.85 and 1.25 for 11/13 serotypes and were <1.29 for the two remaining serotypes. CONCLUSION: The ECL assays were comparable to the WHO reference ELISA and offer a sensitive, time- and serum volume-saving method to quantify serotype-specific anti-PnPS antibodies in pediatric sera. A 0.35 µg/mL threshold will be used for each PCV13 serotype to assess PCV immunogenicity in clinical trials
Perceptions and Practices of Stimulating Children’s Cognitive Development Among Moroccan Immigrant Mothers
We explored the perceptions of children’s cognitive development among Moroccan Arabic and Berber immigrant mothers who cannot read, who are less educated, middle educated or highly educated in the Netherlands. A series of in-depth interviews was conducted with 22 mothers with young children (mean age = 5 years and 6 months). Qualitative data analyses revealed five major themes that are of significant importance to these mothers: moral attitudes, social values and religiousness; conversation, reading and playing as stimulating activities; importance attached to education; parental expectations; attributions of school success. The parental perceptions about the cognitive development of young children differed according to their own educational level. Mothers who cannot read and mothers with less education emphasized the development of moral, social and religious values for strengthening the cultural identity of their children. This sense of identity would enable them to function within their own cultural group and help them to perform well at school. School success was attributed in large part to a combination of the efforts of the child and the school. Middle and highly educated mothers, on the other hand, valued scholastic development and attributed school success to their own efforts and to the kind of support the child received. The ethnic background of the parents, whether Arabic or Berber, did not make a difference in the perceptions
Tachykinins Stimulate a Subset of Mouse Taste Cells
The tachykinins substance P (SP) and neurokinin A (NKA) are present in nociceptive sensory fibers expressing transient receptor potential cation channel, subfamily V, member 1 (TRPV1). These fibers are found extensively in and around the taste buds of several species. Tachykinins are released from nociceptive fibers by irritants such as capsaicin, the active compound found in chili peppers commonly associated with the sensation of spiciness. Using real-time Ca2+-imaging on isolated taste cells, it was observed that SP induces Ca2+ -responses in a subset of taste cells at concentrations in the low nanomolar range. These responses were reversibly inhibited by blocking the SP receptor NK-1R. NKA also induced Ca2+-responses in a subset of taste cells, but only at concentrations in the high nanomolar range. These responses were only partially inhibited by blocking the NKA receptor NK-2R, and were also inhibited by blocking NK-1R indicating that NKA is only active in taste cells at concentrations that activate both receptors. In addition, it was determined that tachykinin signaling in taste cells requires Ca2+-release from endoplasmic reticulum stores. RT-PCR analysis further confirmed that mouse taste buds express NK-1R and NK-2R. Using Ca2+-imaging and single cell RT-PCR, it was determined that the majority of tachykinin-responsive taste cells were Type I (Glial-like) and umami-responsive Type II (Receptor) cells. Importantly, stimulating NK-1R had an additive effect on Ca2+ responses evoked by umami stimuli in Type II (Receptor) cells. This data indicates that tachykinin release from nociceptive sensory fibers in and around taste buds may enhance umami and other taste modalities, providing a possible mechanism for the increased palatability of spicy foods
Management and prevention of chronic obstructive pulmonary disease exacerbations: a state of the art review
Exacerbations of chronic obstructive pulmonary disease (COPD) are important events in the natural history of this prevalent and devastating condition. This review provides a concise, state of the art summary on prevention and management of exacerbations. Considerable new data underpins evidence in support of many preventative interventions, pharmacological and non-pharmacological, that are now available. Challenges remain in developing new approaches, and delivering those that already exist to the right patient at the right time. Management of an exacerbation remains stepwise according to clinical severity, but there is now additional focus on addressing comorbidities and taking the opportunity at acute events to optimise preventative strategies for the future. Ultimately, exacerbations are heterogeneous events in a heterogeneous disease, and an individualised approach is paramount
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