782 research outputs found
Hydrogenation of carbon monoxide over supported ruthenium-iron and related bimetallic catalysts
Differentiation and development of human female germ cells during prenatal gonadogenesis: an immunohistochemical study
Vectorcardiographic changes during extended space flight
To assess the effects of space flight on cardiac electrical properties, vectorcardiograms were taken on the 9 Skylab astronauts during the flights of 28, 59, and 84 days. The Frank lead system was used and observations were made at rest; during 25%, 50% and 75% of maximum exercise; during a short pulse of exercise (150 watts, 2 minutes); and after exercise. Data from 131 in-flight tests were analyzed by computer and compared to preflight and postflight values. Statistically significant increase in QRS vector magnitude (six of nine crewmen); T vector magnitude (five of nine crewmen); and resting PR interval duration (six of nine crewmen) occurred. During exercise the PR interval did not differ from preflight. Exercise heart rates inflight were the same as preflight, but increased in the immediate postflight period. With the exception of the arrhythmias, no deleterious vectorcardiographic changes were observed during the Skylab missions
Novel insights into cochlear information processing
Already Helmholtz profoundly addressed the question how the nonlinearity of the human hearing sensor, the cochlea, might shape human sound perception. At his time, research was, however, obstructed by the lack of experimental data regarding the amplification properties of the inner ear. In the meantime, accurate measuring methods have permitted the comparison of models of the hearing sensor with empirical data, leading to a strong revival of the interest into Helmholtz’s original research questions. In our paper, we describe some recent theoretical and modeling advances in the understanding of the nature of human pitch perception. We reveal a number of to date unexplained human auditory percept effects to be direct consequences of the nonlinear properties of the mammalian hearing sensor. Our insights also demonstrate, as a by-note, the limitations of the present reverse engineering approach towards cochlear implants
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Physical Function and Quality of Life After Resection of Mobile Spine Chondrosarcoma.
Study Design:Retrospective cohort study. Objectives:(1) To assess patient-reported outcomes-physical function, pain, and quality of life-in patients who underwent resection of a mobile spine chondrosarcoma. (2) To assess complications (90 days), readmissions, reoperations, oncological outcomes, and neurologic status. Methods:Thirty-three patients with spinal conventional chondrosarcoma resection between 1984 and 2014 at one hospital were included. The primary outcome measures were-minimally 6 months after surgery-the EuroQol 5 Dimensions (EQ5D), PROMIS-Physical Function, PROMIS-Pain Intensity, and Oswestry (ODI) Disability Index, or Neck (NDI) Disability established in 14 out of 20 alive (70.0%) patients. Complications, readmission, reoperations, oncological outcomes, and neurological status were reported for the complete cohort of 33 patients. Results:After spine chondrosarcoma resection, patients (n = 14) reported worse physical function (median 43, range 22-61, P = .026), worse quality of life (median EQ5D 0.70, range 0.04-1, P = .022), and comparable pain intensity (median 47, range 31-56, P = .362) when compared with US general population values. The median NDI/ODI was 25 (range 0-72) indicating mild to moderate disability. Patients undergoing reoperation had worse patient-reported outcomes than those who did not. Eighteen (55.5%) out of 33 patients suffered complications (90 days), 14 (42.4%) had unplanned readmission, and 13 (39.4%) underwent reoperation. Intralesional resection was associated with increased readmission, reoperation, and recurrence rate. Conclusions:Chondrosarcoma affects quality of life and physical function and its treatment frequently results in complications and reoperations. Our findings can be used to inform future patients about expected outcomes
Molecular determinants of treatment response in human germ cell tumors
PURPOSE: Germ cell tumors (GCTs) are highly sensitive to cisplatin-based
chemotherapy. This feature is unexplained, as is the intrinsic
chemotherapy resistance of mature teratomas and the resistant phenotype of
a minority of refractory GCTs. Various cellular pathways may influence the
efficacy of chemotherapy. Their impact has not been investigated in a
comprehensive study of tumor samples from clinically defined subgroups of
GCT patients. EXPERIMENTAL DESIGN: We investigated proteins involved in
regulation of apoptosis (p53, BAX, BCL-2, and BCL-X(L)), cell cycle
control [p21 and retinoblastoma protein (RB)], and drug export and
inactivation [P-glycoprotein, multidrug resistance-associated protein
(MRP) 1, MRP2, breast cancer resistance protein, lung resistance protein,
metallothionein, and glutathione S-transferase pi] immunohistochemically
in samples of unselected GCT patients (n = 20), patients with advanced
metastatic disease in continuous remission after first-line chemotherapy
(n = 12), and chemotherapy-refractory patients (n = 24). Mature teratoma
components (n = 10) within tumor samples from all groups were analyzed
separately. The apoptotic index was studied by terminal deoxynucleotidyl
transferase-mediated nick end labeling assay. RESULTS: Invasive GCTs of
all groups showed a correlation between wild-type p53 and apoptotic index
(r(s) = 0.66; P < 0.001). The levels of the antiapoptotic proteins BCL-2
and BCL-X(L) were generally low. p21 was hardly detectable and did not
correlate with p53 (r(s) = 0.29; P = 0.07). No significant differences
among the three patient groups were identified regarding any of the
investigated parameters (all Ps were >0.08), even though only individual
samples from chemotherapy-resistant cases showed a strong staining for
MRP2 and GSTpi. In contrast to other components, mature teratomas showed
an intense p21 and RB staining and were mostly positive for MRP2, lung
resistance protein, and GSTpi. CONCLUSIONS: Our results indicate a
multifactorial basis for the chemosensitivity of GCTs with lack of
transporters for cisplatin, of antiapoptotic BCL-2 family members, of p21
induction by p53, and of RB and an intact apoptotic cascade downstream of
p53. These findings suggest a preference for apoptosis over cell cycle
arrest after up-regulation of p53. None of the examined parameters offers
a general explanation for the chemotherapy-resistant phenotype of
refractory tumors. The up-regulation of various factors interfering with
chemotherapy efficacy and ability for a p21-induced cell cycle arrest may
explain the intrinsic chemotherapy resistance of mature teratomas
The Influence of Oral Health Factors on the Quality of Life in Older People: A Systematic Review
Background and Objectives:
The number of people aged 65 years or older is growing substantially. As a result of increased health burden and tooth retention, more oral health problems are expected in this age group. A poor oral health-related quality of life (OHQoL) can compromise a person’s psychological state, social relationships, personal beliefs, and physical health. The aim of this systematic review was to identify oral health factors associated with OHQoL in people aged 65 years or older and to give a comprehensive overview of the body of literature for each oral health factor separately. //
Research Design and Methods:
A comprehensive search was performed in five databases. The following terms were used as index terms or free-text words: “Oral Health,” “Quality of Life,” “Older People.” Two researchers independently assessed studies for eligibility based on predefined criteria. //
Results:
Of 3,702 references retrieved from the databases, 68 studies were eligible and included (9 randomized clinical trials, 6 cohort studies, and 53 cross-sectional studies). All results were reported descriptively. OHQoL in people aged 65 years or older is positively associated with higher number of teeth, higher number of occluding pairs, implant-retained overdentures, and the shortened dental arch concept and negatively associated with xerostomia, orofacial pain, and poor chewing ability. In the current literature, there is no consensus on the association between edentulism, caries, and periodontal conditions and OHQoL. //
Discussion and Implications:
Having a functional dentition (either natural or prosthetic) is important for a good OHQoL, whereas painful or functional complaints are associated with impaired OHQoL
'20 days protected learning' - students' experiences of an Overseas Nurses Programme - 4 years on: A retrospective survey
Background
From September 2005 the Nursing and Midwifery Council (NMC) introduced new arrangements for the registration of non-EU overseas nurses which requires all applicants to undertake '20 days of protected learning' time in the UK and for some, a period of supervised practice. A survey was undertaken at Bournemouth University, which offers a '20 days protected learning only' programme, to elicit overseas nurses' demographic details, experiences in completing the programme and their 'final destinations' once registered.
Methods
An online survey was devised which contained a mixture of tick box and open ended questions which covered demographic details, views on the programme and final destinations This was uploaded to www.SurveyMonkey.com and sent out to nurses who had completed the Overseas Nurses Programme (ONP) with Bournemouth University (n=1050). Quantiative data were analysed using descriptive statistics and the qualitative data were coded and analysed using content analysis .
Results
There were 251 respondents (27.7% response rate). The typical 'profile' of a nurse who responded to the survey was female, aged 25-40 years and had been qualified for more than 5 years with a bachelors degree. The majority came from Australia on a 2 year working holiday visa and the key final destination in the UK, on registration with the NMC, was working for an agency. There were five key findings regarding experience of the programe. Of those surveyed 61.2% did not feel it necessary to undergo an ONP; 71.6% felt that they should be able to complete the programme on-line in their own country; 64.2% that the ONP should only contain information about delivery of healthcare in UK and Legal and professional (NMC) issues; 57% that European nurses should also undergo the same programme and sit an IELTS test; and 68.2% that the programme was too theory orientated; and should have links to practice (21%).
Conclusions
The NMC set the admissions criteria for entry to the register and Standards for an ONP. The findings of this survey raise issues regarding the percieved value and use of this approach for overseas nurses, and it may be helpful to take this into account when considering future policy
Packing of elastic wires in spherical cavities
We investigate the morphologies and maximum packing density of thin wires
packed into spherical cavities. Using simulations and experiments, we find that
ordered as well as disordered structures emerge, depending on the amount of
internal torsion. We find that the highest packing densities are achieved in
low torsion packings for large systems, but in high torsion packings for small
systems. An analysis of both situations is given in terms of energetics and
comparison is made to analytical models of DNA packing in viral capsids.Comment: 4 page
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