287 research outputs found
Acute pain management in children
The greatest advance in pediatric pain medicine is the recognition that untreated pain is a significant cause of morbidity and even mortality after surgical trauma. Accurate assessment of pain in different age groups and the effective treatment of postoperative pain is constantly being refined; with newer drugs being used alone or in combination with other drugs continues to be explored. Several advances in developmental neurobiology and pharmacology, knowledge of new analgesics and newer applications of old analgesics in the last two decades have helped the pediatric anesthesiologist in managing pain in children more efficiently. The latter include administering opioids via the skin and nasal mucosa and their addition into the neuraxial local anesthetics. Systemic opioids, nonsteroidal anti-inflammatory agents and regional analgesics alone or combined with additives are currently used to provide effective postoperative analgesia. These modalities are best utilized when combined as a multimodal approach to treat acute pain in the perioperative setting. The development of receptor specific drugs that can produce pain relief without the untoward side effects of respiratory depression will hasten the recovery and discharge of children after surgery. This review focuses on the overview of acute pain management in children, with an emphasis on pharmacological and regional anesthesia in achieving this goal
Density waves in dry granular media falling through a vertical pipe
We report experimental measurements of density waves in granular materials
flowing down in a capillary tube. The density wave regime occurs at
intermediate flow rates between a low density free fall regime and a high
compactness slower flow.Comment: LaTeX file, 17 pages, 6 EPS figures, Phys.Rev.E (Feb.1996
Shock waves in two-dimensional granular flow: effects of rough walls and polydispersity
We have studied the two-dimensional flow of balls in a small angle funnel,
when either the side walls are rough or the balls are polydisperse. As in
earlier work on monodisperse flows in smooth funnels, we observe the formation
of kinematic shock waves/density waves. We find that for rough walls the flows
are more disordered than for smooth walls and that shock waves generally
propagate more slowly. For rough wall funnel flow, we show that the shock
velocity and frequency obey simple scaling laws. These scaling laws are
consistent with those found for smooth wall flow, but here they are cleaner
since there are fewer packing-site effects and we study a wider range of
parameters. For pipe flow (parallel side walls), rough walls support many shock
waves, while smooth walls exhibit fewer or no shock waves. For funnel flows of
balls with varying sizes, we find that flows with weak polydispersity behave
qualitatively similar to monodisperse flows. For strong polydispersity, scaling
breaks down and the shock waves consist of extended areas where the funnel is
blocked completely.Comment: 11 pages, 15 figures; accepted for PR
Grain Dynamics in a Two-dimensional Granular Flow
We have used particle tracking methods to study the dynamics of individual
balls comprising a granular flow in a small-angle two-dimensional funnel. We
statistically analyze many ball trajectories to examine the mechanisms of shock
propagation. In particular, we study the creation of, and interactions between,
shock waves. We also investigate the role of granular temperature and draw
parallels to traffic flow dynamics.Comment: 17 pages, 24 figures. To appear in Phys.Rev.E. High res./color
figures etc. on http://www.nbi.dk/CATS/Granular/GrainDyn.htm
A bounded confidence approach to understanding user participation in peer production systems
Commons-based peer production does seem to rest upon a paradox. Although
users produce all contents, at the same time participation is commonly on a
voluntary basis, and largely incentivized by achievement of project's goals.
This means that users have to coordinate their actions and goals, in order to
keep themselves from leaving. While this situation is easily explainable for
small groups of highly committed, like-minded individuals, little is known
about large-scale, heterogeneous projects, such as Wikipedia.
In this contribution we present a model of peer production in a large online
community. The model features a dynamic population of bounded confidence users,
and an endogenous process of user departure. Using global sensitivity analysis,
we identify the most important parameters affecting the lifespan of user
participation. We find that the model presents two distinct regimes, and that
the shift between them is governed by the bounded confidence parameter. For low
values of this parameter, users depart almost immediately. For high values,
however, the model produces a bimodal distribution of user lifespan. These
results suggest that user participation to online communities could be
explained in terms of group consensus, and provide a novel connection between
models of opinion dynamics and commons-based peer production.Comment: 17 pages, 5 figures, accepted to SocInfo201
Bioremediation of Industrial Wastes of Oil Refineries as an Environmental Solution for Water Pollution
Four waste water samples were taken from Cairo Oil Refinery Company (CORC) at Mostorod, representing two groups according to their total petroleum hydrocarbon (TPH) contents; the relatively highly polluted samples were taken from El-Taktir American Petroleum Institute (API) separator and the low polluted ones were taken from El-Islah API separator. Mechanical treatments show percentages removal in Total petroleum hydrocarbons (TPH) of 50% and 35% in the outlet effluent of El-Taktir and El-Islah API separators, respectively with TPH concentrations of 250 mg/l and 65 mg/l, respectively. Biotreatment of sterilized mechanically treated water samples with Staphylococcus xylosus for 7 days of incubation at 30 °C, pH 7 and 200 rpm show the high biodegradation efficiency of the isolated bacteria and its preference to work on the high concentration than the low one with percentage removal of 90% and 72.31%, respectively. This led to final TPH concentrations in El-Taktir and El-Islah water samples of 25 mg/l and 18 mg/ l, respectively with approximately complete removal of normal and iso alkanes independent of the TPH concentration. AB1 is also able to degrade Pristane (Pr) and Phytane (Ph) in the highly polluted sample with 73.41% and 54.96%, respectively while it shows complete removal of Pr and Ph in the low polluted sample. Biotreatment shows also high biodegrading efficiency in the unresolved complex mixture (UCM); aromatics, naphthenes and alicyclic hydrocarbons with percentages removal of 88.59% and 68.93% for El-Taktir and El-Islah water samples, respectively
Granular discharge and clogging for tilted hoppers
We measure the flux of spherical glass beads through a hole as a systematic
function of both tilt angle and hole diameter, for two different size beads.
The discharge increases with hole diameter in accord with the Beverloo relation
for both horizontal and vertical holes, but in the latter case with a larger
small-hole cutoff. For large holes the flux decreases linearly in cosine of the
tilt angle, vanishing smoothly somewhat below the angle of repose. For small
holes it vanishes abruptly at a smaller angle. The conditions for zero flux are
discussed in the context of a {\it clogging phase diagram} of flow state vs
tilt angle and ratio of hole to grain size
Arabic Translation, Validation and Cultural Adaptation of the 7-Item Hamilton Depression Rating Scale in Two Community Samples
Objectives: Depression is a common mental disorder, the severity of which is frequently assessed via interview-based clinical scales such as the 7-item Hamilton Depression Rating Scale (HAMD-7). The current study aimed to translate and examine the validity of an Arabic version of the HAMD-7 scale. Methods: This study took place between February and March 2016 in the Psychiatry Department of King Saud University, Riyadh, Saudi Arabia. The HAMD-7 scale was translated into Arabic using forward and backward translation methods. A total of 153 Arabic speakers were recruited to test the translated scale, including 57 medical students and 96 members of the general public. The Arabic version of the HAMD-7 scale was completed by trained investigators during face-toface interviews with the participants. In order to assess convergent validity, participants also completed an Arabic
version of the self-assessed Patient Health Questionnaire-9 (PHQ-9) scale. Subsequently, the test-retest reliability of the translated HAMD-7 scale was evaluated two weeks later during a second interview. Results: Overall, HAMD-7 scores were positively correlated with PHQ-9 scores (r = 0.633–0.749). Moreover, the translated HAMD-7 scale proved to be reliable in terms of test-retest reliability (intra-class correlation coefficient: 0.807; P <0.001). With regards to internal consistency, the Cronbach’s α values ranged between 0.607–0.756. Conclusion: The Arabic HAMD-7 scale was found to be reliable and valid among two samples of Arabic speakers in Saudi Arabia. However, further research among Arab-speaking patients diagnosed with depression is needed in order to establish its usefulness in assessing the severity of depressive symptoms.
Keywords: Psychiatry; Depression; Psychometrics; Validity and Reliability; Translation; Questionnaire Design;Â Saudi Arabia
PATHOGEN-SPECIFIC ANTIBODY PROFILES IN PATIENTS WITH SEVERE SYSTEMIC INFECTIONS
Infections are often caused by pathobionts, endogenous bacteria that belong to the microbiota. Trauma and surgical intervention can allow bacteria to overcome host defences, ultimately leading to sepsis if left untreated. One of the main defence strategies of the immune system is the production of highly specific antibodies. In the present proof-of-concept study, plasma antibodies against 9 major pathogens were measured in sepsis patients, as an example of severe systemic infections. The binding of plasma antibodies to bacterial extracellular proteins was quantified using a semi-automated immunoblot assay. Comparison of the pathogen-specific antibody levels before and after infection showed an increase in plasma IgG in 20 out of 37 tested patients. This host-directed approach extended the results of pathogen-oriented microbiological and PCR diagnostics: a specific antibody response to additional bacteria was frequently observed, indicating unrecognised poly-microbial invasion. This might explain some cases of failed, seemingly targeted antibiotic treatment
Isolation, characterization, and ELISA applications of alkaline phosphatase and acetylcholinesterase from Moniezia expansa
Moniezia expansa worms are a significant source of alkaline phosphatase (ALP) and acetylcholinesterase (AChE) enzymes. The current study presents a simple and reproducible ALP and AChE purification method from Moniezia expansa helminthes by precipitating the proteins with ammonium sulfate and chromatography on the Sephacryl S-300 column. The M. expansa ALP purified at 1070.8 U/mg, displaying 6.0 purification folds and 53.6% yield, while M. expansa AChE is at 5250 U/mg, displaying 2.0 purification folds and 43% yield. The M. expansa ALP isoenzyme displayed its optimum activity at pH 9.6, while the M. expansa AChE isoenzyme displayed its optimum activity at pH 8.0. The affinity of M. expansa ALP for several substrates revealed that p-nitrophenyl phosphate preferentially cleaved with a Km value of 4.4 mM. M. expansa AChE preferentially cleaved acetylthiocholine iodide with a Km value of 0.9 mM. M. expansa ALP is strongly stimulated with Co2+, Mn2+, Ni2+, and Mg2+and reduced with Zn2+, Cu2+, Ca2+, EDTA and DTT. On the other hand, M. expansa AChE is significantly induced with Co2+, Zn2+, and Ni2+and inhibited with Mg2+, Ca2+, EDTA, 1,10-phenanthroline and eserine. The antisera of the purified M. expansa ALP and AChE found effective for determining the two enzymes in different unknown sera from different animal species, including humans, sheep and fish. These results may provide a possible future application of such enzymes in producing ALP and AChE-coated ELISA plates for research purposes
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