2,347 research outputs found
Bypass rod transfers heat developed in thermionic diode
In a thermionic diode, a cesium tube joining the emitter-collector area and the cesium reservoir is fitted with a copper bypass rod held in place by two standoff brackets. The rod transfers heat from the emitter-collector to the reservoir without going through the ceramic seal structure which surrounds the cesium tube and cannot sustain large temperature gradients
Six-converter solar thermionic generator Final report, 10 Jan. 1967 - 31 Mar. 1968
Six converter solar thermionic generato
When a risky prospect is valued more than its best possible outcome
In this paper, we document a violation of normative and descriptive models of decision making under risk. In contrast to uncertainty effects found by Gneezy, List and Wu (2006), some subjects in our experiments valued certain lotteries more than the best possible outcome. We show that the likelihood of observing this effect is positively related to the probability of winning the lottery and negatively related to the value of the maximum outcome. We also demonstrate that this effect can be partially attributed to subjects’ competitiveness and level of comprehension of the lottery mechanism; the competitiveness effects far outweighing comprehension effects.lottery, risk, competitiveness, Vickrey auctions
Uticaj profesionalnog stresa na povrede na poslu i radnu sposobnost medicinskog osoblja
Introduction: Stress in the workplace in the health sector is in
expansion.
Objective: Assessment of the occupational stress index and types of
stressors in certain areas of the health sector and their impact on the
development of occupational injuries and at work ability.
Methodology: The study group consisted of 448 health care personnel
and control of 157 administrative workers. The application of the
questionnaire were analyzed the presence and level of occupational
stressors in their workplaces. The complete diagnostics of health
status were performed. The data of the length of temporary incapacity
for work, injuries at work and permanent work capacity were
analyzed.
Results: Total OSI was significantly higher in the examined group
(69.24 ± 10.10) compared to the control group (39.38 ± 7.44) (t =
39.19, p <0.001). Total OSI was significantly higher among
employees in institutions of secondary and tertiary health care levels
(74.94 ± 7.43) compared to employees in institutions at the primary
health care level (58.87 ± 4.47) (t = 24.891, p <0.001 ). Doctors are
exposed to a significantly higher level of stress than the nurses (73.21
± 10.13; 65.47 ± 8.52) (t = 8.725, p <0.001). Mental disorders,
occupational disease and hypertension were significantly more present
in the examined group compared to the controls (p = 0.043; Χ2 =
4.03; Χ2 = 31.30, p <0.001). Number of working days lost due to
injuries at work, occupational and other diseases was significantly
higher in the study than in the control group (p <0.001). Number of
days lost due to illness, injury at work and occupational diseases was
significantly higher among employees in institutions of secondary and
tertiary health care levels in relation to employees in institutions at the
primary health care level (z = 10.56, t = 6.44, t = 5.23; p <0.001).
There was a significant correlation between OSI and workplace
injuries, length of temporary work disability and complete permanent
loss of working ability. The correlation is highly significant in health
care personnel in surgical branches of medical activity.
Conclusion: Professional stress have significantly effects on the
development of the occupational injuries and at work ability of health
care personnel, which needs the preventive measures
Relevant distance between two different instances of the same potential energy in protein folding
In the context of complex systems and, particularly, of protein folding, a
physically meaningful distance is defined which allows to make useful
statistical statements about the way in which energy differences are modified
when two different instances of the same potential-energy function are used.
When the two instances arise from the fact that different algorithms or
different approximations are used, the distance herein defined may be used to
evaluate the relative accuracy of the two methods. When the difference is due
to a change in the free parameters of which the potential depends on, the
distance can be used to quantify, in each region of parameter space, the
robustness of the modeling to such a change and this, in turn, may be used to
assess the significance of a parameters' fit. Both cases are illustrated with a
practical example: the study of the Poisson-based solvation energy in the
Trp-Cage protein (PDB code 1L2Y).Comment: 20 pages, 6 figures, LaTeX file, elsart style. v1: Aknowledgments
modified. v2: y-values of fig. 5 and 6 corrected. v3: Journal-ref added,
aknowledgements modified and fig. 1 and 2 correcte
Exploring the Levinthal limit in protein folding
According to the thermodynamic hypothesis, the native state of proteins is uniquely defined by their amino acid sequence. On the other hand, according to Levinthal, the native state is just a local minimum of the free energy and a given amino acid sequence, in the same thermodynamic conditions, can assume many, very different structures that are as thermodynamically stable as the native state. This is the Levinthal limit explored in this work. Using computer simulations, we compare the interactions that stabilize the native state of four different proteins with those that stabilize three non-native states of each protein and find that the nature of the interactions is very similar for all such 16 conformers. Furthermore, an enhancement of the degree of fluctuation of the non-native conformers can be explained by an insufficient relaxation to their local free energy minimum. These results favor Levinthal's hypothesis that protein folding is a kinetic non-equilibrium process.FCT - Foundation for Science and Technology, Portugal [UID/Multi/04326/2013]; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP); Conselho Nacional de Desenvolvimento Cientia co e Tecnologico (CNPq
Guidelines for pre-clinical assessment of the acetylcholine receptor-specific passive transfer myasthenia gravis model - recommendations for methods and experimental designs.
Antibodies against the muscle acetylcholine receptor (AChR) are the most common cause of myasthenia gravis (MG). Passive transfer of AChR antibodies from MG patients into animals reproduces key features of human disease, including antigenic modulation of the AChR, complement-mediated damage of the neuromuscular junction, and muscle weakness. Similarly, AChR antibodies generated by active immunization in experimental autoimmune MG models can subsequently be passively transferred to other animals and induce weakness. The passive transfer model is useful to test therapeutic strategies aimed at the effector mechanism of the autoantibodies. Here we summarize published and unpublished experience using the AChR passive transfer MG model in mice, rats and rhesus monkeys, and give recommendations for the design of preclinical studies in order to facilitate translation of positive and negative results to improve MG therapies
Cerebral fat embolism and the "starfield" pattern: a case report
Nearly all long-bone fractures are accompanied by some form of fat embolism. The rare complication of clinically significant fat embolism syndrome, however, occurs in only 0.9-2.2% of cases. The clinical triad of fat embolism syndrome consists of respiratory distress, altered mental status, and petechial rash. Cerebral fat embolism causes the neurologic involvement seen in fat embolism syndrome. A 19-year-old African-American male was admitted with gunshot wounds to his right hand and right knee. He had diffuse hyperactive deep tendon reflexes, bilateral ankle clonus and decerebrate posturing with a Glasgow Coma Scale (GCS) score of 4T. Subsequent MRI of the brain showed innumerable punctate areas of restricted diffusion consistent with "starfield" pattern. On a 10-week follow up he has a normal neurological examination and he is discharged home. Despite the severity of the neurologic insult upon initial presentation, the majority of case reports on cerebral fat embolism illustrate that cerebral dysfunction associated with cerebral fat embolism is reversible. When neurologic deterioration occurs in the non-head trauma patient, then a systemic cause such as fat emboli should be considered. We describe a patient with non-head trauma who demonstrated the classic "starfield" pattern on diffusion-weighted MRI imaging
PATRIOT: A phase I study to assess the tolerability, safety and biological effects of a specific ataxia telangiectasia and Rad3-related (ATR) inhibitor (AZD6738) as a single agent and in combination with palliative radiation therapy in patients with solid tumours
Tumour control rates from radiation therapy (RT) are limited by normal tissue toxicities. Novel strategies are required to selectively sensitize tumour cells to radiation-induced DNA damage. The G2 cell cycle checkpoint is an attractive target for this, as normal cells will be protected by their intact G1 checkpoint, which is lost in the majority of cancer cells. ATR is an important mediator of the G2 checkpoint. Preclinical data suggest that ATR inhibition will sensitise to DNA damaging therapies, including RT. This multi-part phase 1 trial aims to assess safety and tolerability and preliminary anti-tumour activity of the ATR inhibitor AZD6738 as monotherapy and in combination with palliative RT, escalating both drug and radiation dose at a dose-fractionation relevant to radical treatment. The design aims to test a novel agent at the earliest stage of clinical development and assess safety in combination with RT, with the aim of moving to a radically-treated population if tolerated. Methods: Participants have advanced solid tumours without standard systemic therapy options. The trial comprises three parts: parts A and B will assess AZD6738 as a single agent in dose escalation to MTD (part A), followed by expansion cohorts enriched for defective DNA damage response (part B). Part C will assess AZD6738 in combination with palliative RT in which participants will receive 20 Gy in 10 fractions, with per cohort escalation of drug dose to monotherapy MTD if tolerated. At the highest tolerated combination dose, the RT dose will be escalated to 30 Gy in 15 fractions. Maintenance AZD6738 post-RT will be tested at the highest tolerated combination dose. The study opened in August 2014. The study is dose escalating in part A and part C has opened and treated its first patient. Part B will open when dose escalation has completed. PATRIOT is sponsored by The Royal Marsden, funded by the Cancer Research UK/AstraZeneca Combinations Alliance and supported by supply of free drug and distribution costs from Astra Zeneca. Clinical trial information: NCT0222392
Publication and patent analysis of European researchers in the field of production technology and manufacturing systems
This paper develops a structured comparison among a sample of European researchers in the field of Production Technology and Manufacturing Systems, on the basis of scientific publications and patents. Researchers are evaluated and compared by a variegated set of indicators concerning (1) the output of individual researchers and (2) that of groups of researchers from the same country. While not claiming to be exhaustive, the results of this preliminary study provide a rough indication of the publishing and patenting activity of researchers in the field of interest, identifying (dis)similarities between different countries. Of particular interest is a proposal for aggregating analysis results by means of maps based on publication and patent indicators. A large amount of empirical data are presented and discusse
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