527 research outputs found
A multipoint field ionization source Final report, 11 Nov. 1966 - 12 Apr. 1968
Experimental study on use of field ionization and electron emission as ion sources for mass spectrometer
The Effectiveness of Prophylactic Ankle Braces in Reducing the Incidence of Acute Ankle Injuries in Adolescent Athletes: A Critically Appraised Topic
Clinical Scenario: Ankle injuries constitute a large number of injuries sustained by adolescent athletes participating in high school athletics. Prophylactic ankle bracing may be an effective and efficient method to reduce the incidence of ankle injuries in adolescent athletes in the secondary-school setting. Clinical Question: Do prophylactic ankle braces reduce the incidence of acute ankle injuries in adolescent athletes? Summary of Key Findings: Two of the three included studies reported that prophylactic ankle braces reduced the incidence of ankle injuries compared with no ankle bracing. Clinical Bottom Line: There is moderate evidence to support the use of prophylactic ankle braces in adolescent athletes, particularly those who participate in football and basketball, to reduce the incidence of acute ankle injuries. Strength of Recommendation: Grade B evidence exists that prophylactic ankle braces reduce the incidence of acute ankle injuries in adolescent athletes
Microarray and pathway analysis reveals decreased CDC25A and increased CDC42 associated with slow growth of BCL2 overexpressing immortalized breast cell line
Bcl-2 is an anti-apoptotic protein that is frequently overex-pressed in cancer cells but its role in
carcinogenesis is not clear. We are interested in how Bcl-2 expression affects non-cancerous breast
cells and its role in the cell cycle. We prepared an MCF10A breast epithelial cell line that stably
overexpressed Bcl-2. We analyzed the cells by flow cytometry after synchronization, and used cDNA
microarrays with quantitative reverse-transcription PCR (qRTPCR) to determine differences in gene
expression. The microarray data was subjected to two pathway analysis tools, parametric analysis of
gene set enrichment (PAGE) and ingenuity pathway analysis (IPA), and western analysis was carried
out to determine the correlation between mRNA and protein levels. The MCF10A/Bcl-2 cells
exhibited a slow-growth phenotype compared to control MCF10A/Neo cells that we attributed to a
slowing of the G1-S cell cycle transition. A total of 363 genes were differentially expressed by at
least two-fold, 307 upregulated and 56 downregulated. PAGE identified 22 significantly changed
gene sets. The highest ranked network of genes identified by IPA contained 24 genes. Genes that
were chosen for further analysis were confirmed by qRT-PCR, however, the western analysis did
not always confirm differential expression of the proteins. Downregulation of the phosphatase
CDC25A could solely be responsible for the slow growth pheno-type in MCF10A/Bcl-2 cells.
Increased levels of GTPase Cdc42 could be adding to this effect. PAGE and IPA are valuable tools
for microarray analysis, but protein expression results do not always follow mRNA expression
results. Originally published Cell Cycle, Vol. 7, No. 19, Oct. 200
The effect of a 24-hour photoperiod on the survival, growth and swim bladder inflation of pre-flexion yellowfin tuna (Thunnus albacares) larvae
The effects of two different continuous photoperiod regimes on survival, growth and swim bladder inflation of pre-flexion yellowfin tuna (Thunnus albacares) larvae were investigated. Each photoperiod regime was tested twice with a different larval cohort to confirm the observed results. Trials 1 and 2 tested the effect of a reduced night-time light intensity (10-molesm-2s-1=30% of the daytime intensity) and found that those larvae reared for 8days under the 24h lighting (24-L) photoperiod exhibited a slight improvement in survival compared to those reared under the control photoperiod of 12h light (12-L), however these improvements were not significant. In addition, those larvae reared under this photoperiod regime were equal in length to those in the control. Trials 3 and 4 compared the same variables in larvae reared under a continuous photoperiod (24-L) with a constant light intensity of 30-molesm-2s-1, against those reared under the aforementioned 12-L photoperiod. Survival of larvae under the continuous photoperiods were 9±1% (n=2) and 10±2% (n=3) for Trials 3 and 4, respectively, compared to less than 1% in both control treatments; differences that in both cases were highly significant. In addition, in both trials larvae cultured under the 24-L photoperiod were significantly larger and exhibited more advanced development than those reared under the 12-L photoperiod, however swim bladder inflation was significantly lower. We suggest that the improved survival and growth achieved under a continuous photoperiod is due to the extended foraging time combined with the prevention of mortality caused by night-time sinking
Population pharmacokinetics-based recommendations for a single delayed or missed dose of nusinersen
Nusinersen is an antisense oligonucleotide approved for the treatment of spinal muscular atrophy. The drug is given intrathecally at 12 mg, beginning with 3 loading doses at 2-week intervals, a fourth loading dose 30 days thereafter, and maintenance doses at 4-month intervals. This population pharmacokinetic model was developed to clarify how to maintain targeted nusinersen exposure after an unforeseen one-time delay or missed dose. Simulations demonstrated that the impact of a one-time delay in dosing or a missed dose on median cerebrospinal fluid exposures depended on duration of interruption and the regimen phase in which it occurred. Delays in loading doses delayed reaching the peak trough concentration by approximately the duration of the interruption. Resumption of the regimen as soon as possible resulted in achieving steady state trough concentration upon completion of the loading phase. A short delay (30-90 days) during the maintenance phase led to prolonged lower median cerebrospinal fluid concentration if all subsequent doses were shifted by the same 4-month interval. However, administration of the delayed dose, followed by the subsequent dose as originally scheduled, rapidly restored trough concentration. If a dose must be delayed, patients should return to the original dosing schedule as soon as possible
Diving And Amphibious Behaviour In Free-Living Crocodylus porosus
Twelve estuarine crocodiles (6-51 kg) were fitted with recording back packs in order to study the longevity, frequency and daily/tidal rhythm of natural dives by crocodiles free-living in their familiar habitat. Despite disinterest shown by captive crocodiles in removing their jackets in tank trials, all but one of the seven crocodiles recaptured 5-16 days after release had shed their jackets and recorders. Results from the 9.75 kg animal showed that it had a prolonged emergence during each daylight low tide (basking?), that it dived mainly in daylight hours (feeding?), predominantly in the upper half of the tide and that most dives were of very short duration (1-5 minutes). Even the longest dive, 30 minutes, was well within the aerobic capabilities of a crocodile this size. Although these results are from a single animal, and may turn out to be quite atypical, if attachment problems are solved, the method has clear potential for revealing much about the daily activity patterns of free-ranging crocodiles and other animals
The medical student
The Medical Student was published from 1888-1921 by the students of Boston University School of Medicine
Position Statement: Sharing of Clinical Research Data in Spinal Muscular Atrophy to Accelerate Research and Improve Outcomes for Patients
Clinical Meaningfulness of the Changes in Muscle Performance and Physical Function Associated With Testosterone Administration in Older Men With Mobility Limitation
Context. Testosterone in Older Men with Mobility Limitations Trial determined the effects of testosterone on muscle performance and physical function in older men with mobility limitation. Trial's Data and Safety Monitoring Board recommended enrollment cessation due to increased frequency of adverse events in testosterone arm. The changes in muscle performance and physical function were evaluated in relation to participant's perception of change. Methods. Men aged 65 years and older, with mobility limitation, total testosterone 100-350 ng/dL, or free testosterone less than 50 pg/mL, were randomized to placebo or 10 g testosterone gel daily for 6 months. Primary outcome was leg-press strength. Secondary outcomes included chest-press strength, stair-climb, 40-m walk, muscle mass, physical activity, self-reported function, and fatigue. Proportions of participants exceeding minimally important difference in study arms were compared. Results. Of 209 randomized participants, 165 had follow-up efficacy measures. Mean (SD) age was 74 (5.4) years and short physical performance battery score 7.7 (1.4). Testosterone arm exhibited greater improvements in leg-press strength, chest-press strength and power, and loaded stair-climb than placebo. Compared with placebo, significantly greater proportion of men receiving testosterone improved their leg-press and chest-press strengths (43% vs 18%, p = .01) and stair-climbing power (28% vs 10%, p = .03) more than minimally important difference. Increases in leg-press strength and stair-climbing power were associated with changes in testosterone levels and muscle mass. Physical activity, walking speed, self-reported function, and fatigue did not change. Conclusions. Testosterone administration in older men with mobility limitation was associated with patient-important improvements in muscle strength and stair-climbing power. Improvements in muscle strength and only some physical function measures should be weighed against the risk of adverse events in this populatio
Human Computer Interaction Meets Psychophysiology: A Critical Perspective
Human computer interaction (HCI) groups are more and more often exploring the utility of new, lower cost electroencephalography (EEG) interfaces for assessing user engagement and experience as well as for directly controlling computers. While the potential benefits of using EEG are considerable, we argue that research is easily driven by what we term naïve neurorealism. That is, data obtained with psychophysiological devices have poor reliability and uncertain validity, making inferences on mental states difficult. This means that unless sufficient care is taken to address the inherent shortcomings, the contributions of psychophysiological human computer interaction are limited to their novelty value rather than bringing scientific advance. Here, we outline the nature and severity of the reliability and validity problems and give practical suggestions for HCI researchers and reviewers on the way forward, and which obstacles to avoid. We hope that this critical perspective helps to promote good practice in the emerging field of psychophysiology in HCI
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