653 research outputs found
Effect of secondary swirl in supersonic gas and plasma flows in self-vacuuming vortex tube
This article presents the results of simulation for a special type of vortex
tubes - self-vacuuming vortex tube (SVVT), for which extreme values of
temperature separation and vacuum are realized. The main results of this study
are the flow structure in the SVVT and energy loss estimations on oblique shock
waves, gas friction, instant expansion and organization of vortex bundles in
SVVT.Comment: 6 pages, 5 figure
Does phase 2 of the expiratory PCO2 versus volume curve have diagnostic value in emphysema patients?
It has been postulated that serial inhomogeneity of ventilation in the
peripheral airways in emphysema is represented by the shape of expiratory
carbon dioxide tension versus volume curve. We examined the diagnostic
value of this test in patients with various degrees of emphysema. The
volumes between 25-50% (V25-50) and 25-75% (V25-75) of the expiratory
carbon dioxide tension versus volume curve were determined in 29
emphysematous patients (20 severely obstructed and 9 moderately
obstructed), 12 asthma patients in exacerbation of symptoms, and 28
healthy controls. Discriminant analysis was used to examine whether these
diagnostic groups could be separated. With regard to phase 2 of the
expiratory CO2 versus volume curve (mixture of anatomic deadspace and
alveolar air), a plot of intercept versus slope of the relationships of
(V25-50) and (V25-75) versus inspiratory volume (VI) from functional
residual capacity (FRC), obtained during natural breathing frequency,
proved to be most discriminating in the separation between healthy
controls and severely obstructed emphysema patients. Separating healthy
controls and severely obstructed emphysema patients on the basis of the
discriminant line for V25-50, 9 of the 12 asthma patients in exacerbation
were classified as normal, and only 5 of the 9 moderately obstructed
emphysema patients as emphysematous. For V25-75 involvement of phase 3 of
the curve (alveolar plateau) in asthma patients in exacerbation caused a
marked overlap with the severely obstructed emphysema patients. In the
healthy controls, a fixed breathing frequency of 20 breaths.min-1 led to
an increase of both volumes.(ABSTRACT TRUNCATED AT 250 WORDS
Dead space and slope indices from the expiratory carbon dioxide tension-volume curve
The slope of phase 3 and three noninvasively determined dead space
estimates derived from the expiratory carbon dioxide tension (PCO2) versus
volume curve, including the Bohr dead space (VD,Bohr), the Fowler dead
space (VD,Fowler) and pre-interface expirate (PIE), were investigated in
28 healthy control subjects, 12 asthma and 29 emphysema patients (20
severely obstructed and nine moderately obstructed) with the aim to
establish diagnostic value. Because breath volume and frequency are
closely related to CO2 elimination, the recording procedures included
varying breath volumes in all subjects during self-chosen/natural
breathing frequency, and fixed frequencies of 10, 15 and 20 breaths x
min(-1) with varying breath volumes only in the healthy controls. From the
relationships of the variables with tidal volume (VT), the values at 1 L
were estimated to compare the groups. The slopes of phase 3 and VD,Bohr at
1 L VT showed the most significant difference between controls and
patients with asthma or emphysema, compared to the other two dead space
estimates, and were related to the degree of airways obstruction.
Discrimination between no-emphysema (asthma and controls) and emphysema
patients was possible on the basis of a plot of intercept and slope of the
relationship between VD,Bohr and VT. A combination of both the slope of
phase 3 and VD,Bohr of a breath of 1 L was equally discriminating. The
influence of fixed frequencies in the controls did not change the results.
The conclusion is that Bohr dead space in relation to tidal volume seems
to have diagnostic properties separating patients with asthma from
patients with emphysema with the same degree of airways obstruction.
Equally discriminating was a combination of both phase 3 and Bohr dead
space of a breath of 1 L. The different pathophysiological mechanisms in
asthma and emphysema leading to airways obstruction are probably
responsible for these results
Shunting of recurrent post-traumatic syringomyelia into the fourth ventricle: a case report
<p>Abstract</p> <p>Introduction</p> <p>Post-traumatic syringomyelia is a progressive degenerative disorder that is a well-recognized sequela of spinal cord injury. There is currently no optimal intervention capable of producing satisfactory long-term clinical results.</p> <p>Case presentation</p> <p>In this report, we present a 55-year-old Asian man with recurrent syringomyelia after shunt treatment. The syrinx extended from the thoracic cord into the medulla. We used a silicone tube to create a channel connecting the syrinx cavity directly to the fourth ventricle. The patient made a good recovery and follow-up magnetic resonance imaging revealed a considerable diminution in the size of the syrinx.</p> <p>Conclusions</p> <p>We present a new approach that has the potential to improve the outcome of patients with recurrent post-traumatic syringomyelia, who cannot be treated by conventional methods.</p
KINERJA PELAYANAN DINAS KEPENDUDUKAN DAN PENCATATAN SIPIL KEPADA MASYARAKAT
The objectives of this research are to investigate: (1) the performance of the Population and Civil Registry Office at Karanganyar regency; (2) the factors influencing the performance of the Population and Civil Registry Office at Karanganyar regency; and (3) the efforts taken to improve the performance of the Population and Civil Registry Office at Karanganyar regency.This research used a single embedded case study with the qualitative method. The sources of the research were informants, locations, documents or archives. The samples of the research were taken by using the purposive sampling technique and the snowball sampling technique. The data of the research were gathered through in-depth interview, observation, and documentation and were then validated by using the data source and data gathering method triangulations. They were analyzed by using the interactive technique of analysis.The results of the research show that the performance of the Population and Civil Registry Office in extending services to the community in Karanganyar regency has not been optimal for the community feels less satisfied with the services in terms of the timeliness and comfort of services. Such a performance is due to the limited number of its employees and their low ability in the computerization system. The factors affecting the performance of the Population and Civil Registry Office at Karanganyar regency include (1) work motivation of the employees, (2) ability of the employees, and (3) facility and infrastructure. The efforts taken so as to improve the performance of the Population and Civil Registry Office at Karanganyar regency are, among others, highly motivating and encouraging the employees to perform better through punishment and reward system. The employees shall be given training on computerization system. The facility and infrastructure shall be added in terms of quantity and completeness. Keywords: Performance and services to community
Enhancing reuse of data and biological material in medical research : from FAIR to FAIR-Health
The known challenge of underutilization of data and biological material from biorepositories as potential resources
formedical research has been the focus of discussion for over a decade. Recently developed guidelines for improved
data availability and reusability—entitled FAIR Principles (Findability, Accessibility, Interoperability, and
Reusability)—are likely to address only parts of the problem. In this article,we argue that biologicalmaterial and data
should be viewed as a unified resource. This approach would facilitate access to complete provenance information,
which is a prerequisite for reproducibility and meaningful integration of the data. A unified view also allows for
optimization of long-term storage strategies, as demonstrated in the case of biobanks.Wepropose an extension of the
FAIR Principles to include the following additional components: (1) quality aspects related to research reproducibility
and meaningful reuse of the data, (2) incentives to stimulate effective enrichment of data sets and biological
material collections and its reuse on all levels, and (3) privacy-respecting approaches for working with the human
material and data. These FAIR-Health principles should then be applied to both the biological material and data. We
also propose the development of common guidelines for cloud architectures, due to the unprecedented growth of
volume and breadth of medical data generation, as well as the associated need to process the data efficiently.peer-reviewe
Diffraction of complex molecules by structures made of light
We demonstrate that structures made of light can be used to coherently
control the motion of complex molecules. In particular, we show diffraction of
the fullerenes C60 and C70 at a thin grating based on a standing light wave. We
prove experimentally that the principles of this effect, well known from atom
optics, can be successfully extended to massive and large molecules which are
internally in a thermodynamic mixed state and which do not exhibit narrow
optical resonances. Our results will be important for the observation of
quantum interference with even larger and more complex objects.Comment: 4 pages, 3 figure
Biomarker Research and Development for Coronavirus Disease 2019 (COVID-19): European Medical Research Infrastructures Call for Global Coordination
An effective response to the coronavirus disease 2019 (COVID-19) pandemic requires a better understanding of the biology of the infection and the identification of validated biomarker profiles that would increase the availability, accuracy, and speed of COVID-19 testing. Here, we describe the strategic objectives and action lines of the European Alliance of Medical Research Infrastructures (AMRI), established to improve the research process and tackle challenges related to diagnostic tests and biomarker development. Recommendations include: the creation of a European taskforce for validation of novel diagnostic products, the definition and promotion of criteria for COVID-19 samples biobanking, the identification and validation of biomarkers as clinical endpoints for clinical trials, and the definition of immune biomarker signatures at different stages of the disease. An effective management of the COVID-19 pandemic is possible only if there is a high level of knowledge and coordination between the public and private sectors within a robust quality framework.Peer reviewe
The value of plasma markers for the clinical behaviour of phaeochromocytomas
OBJECTIVE: Phaeochromocytomas (PCCs) are widely known for their clinical
unpredictability. This study intends to define predictive plasma markers
for their variable postoperative behaviour. Furthermore, the diagnostic
accuracy of these plasma tests was determined. DESIGN AND METHODS: A
retrospective correlative study was performed in a series of 83 operated
and four autopsied patients in order to correlate preoperative
catecholamine (CAT) levels of 103 PCCs with their clinical behaviour. In a
subset of cases, chromogranin-A (Chr-A) and enzymes/precursors of the CAT
biosynthesis were studied for their predictive value. RESULTS: Basal CAT
levels were elevated in 81/87 instances (sensitivity: 93%). Four of six
cases with normal measurements showed only medullary hyperplasia. Larger
PCCs, particularly those showing necrosis, capsular and vascular invasion,
secreted higher CAT levels. Bilateral, hereditary tumours were less
productive than their unilateral counterparts. Extra-adrenal PCCs secreted
significantly lower levels of epinephrine (EPI) than intra-adrenal
tumours. Fourteen patients developed metastases. According to Kaplan-Meier
estimations, patients with higher levels of dopamine, norepinephrine (NE)
and aromatic l-amino acid decarboxylase as well as lower ratios of
EPI/EPI+NE, had significantly shorter metastases-free intervals. Existence
of preoperative hypertension, left ventricular hypertrophy and measured
blood pressures showed significant positive relationships with CAT levels,
but not with Chr-A. CONCLUSIONS: These data showed that plasma CAT
measurement is a sensitive method in the diagnostic work-up of PCCs. Those
tumours producing normal levels are commonly small and asymptomatic.
Furthermore, certain secretion patterns are indicative of the presence of
metastases as well as the size and site of spor
[(123)I]metaiodobenzylguanidine and [(111)In]octreotide uptake in begnign and malignant pheochromocytomas
Selecting the appropriate approach for resection and follow-up of
pheochromocytomas (PCCs) is highly dependent upon reliable localization
and exclusion of multifocal, bilateral, or metastatic disease.
Metaiodobenzylguanidine (MIBG) scintigraphy was developed for functional
localization of catecholamine-secreting tissues. Somatostatin receptor
imaging (SRI) has a high sensitivity for localizing head and neck
paragangliomas, but studies of intraabdominal PCCs are rare. In thi
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