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PubMed2000

Faith and health self-management of rural older adults.

This analysis uses in-depth interview data collected from 145 African American, European American and Native American men and women aged 70 and older who reside in two rural North Carolina counties to understand the role of religious faith and prayer in the health self-management of these older adults. The analysis addresses three specific questions: how do these older adults use religion to help them manage their health; are there ethnic and gender differences in the use of religion; and are differences in health status related to differences in the use of religion? The integral role of religion in the lives of these older rural adults is an overarching theme present in the interview texts. Six major themes link religion and health self-management: (1) prayer and faith in health self-management, (2) reading the Bible, (3) church services, (4) mental and spiritual health, (5) stories of physical healing, and (6) ambivalence. Faith and religious activities provide an anchor in the lives of these older adults. There is little variation in the use of religion for health self-management by gender, ethnicity or health status. These results suggest that the strength of religion in rural culture may limit the effectiveness of general religiosity scales to discern the relationship of religion to health and health behavior in rural populations.

Journal Article↗

PubMed2002

Correlates of self-perceptions of spirituality in American adults.

To advance knowledge in the study of spirituality and physical health, we examined sociodemographic, behavioral, and attitudinal correlates of self-perceptions of spirituality. Participants were a nationally representative sample of 1,422 adult respondents to the 1998 General Social Survey. They were asked, among other things, to rate themselves on the depth of their spirituality and the depth of their religiousness. Results indicated that, after adjustment for religiousness, self-perceptions of spirituality were positively correlated with being female (r = .07, p < .01), having a higher education (r = .12, p < .001), and having no religion (r = .10, p < .001) and inversely correlated with age (r = -.06, p < .05) and being Catholic (r = -.08, p < .01). After adjustment for these sociodemographic factors, self-perceptions of spirituality were associated with high levels of religious or spiritual activities (range in correlations = .12-.38, all p < .001), low cynical mistrust, and low political conservatism (both r = -.08, p < .01). The population was divided into 4 groups based on their self-perceptions of degree of spirituality and degree of religiousness. The spiritual and religious group had a higherfrequency of attending services, praying, meditating, reading the Bible, and daily spiritual experience than any of the other 3 groups (all differences p < .05) and had less distress and less mistrust than the religious-only group (p < .05 for both). However, they were also more intolerant than either of the nonreligious groups (p < .05 for both) and similar on intolerance to the religious-only group. We conclude that sociodemographicfactors could confound any observed association between spirituality and health and should be controlled. Moreover, individuals who perceive themselves to be both spiritual and religious may be at particularly low risk for morbidity and mortality based on their good psychological status and ongoing restorative activities.

Adult↗

PubMed1991

Neuronal activity in frontal speech area 44 of the human cerebral cortex during word recognition.

The activity of neurons was recorded from cortical speech area 44 of human patients with diagnostic and/or therapeutical depth electrodes while they were performing word recognition and object naming tasks. Some cells responded selectively to either semantic or phonological aspects of word processing with the same latency, others responded consecutively to both semantic and phonological features. The present finding provides the first demonstration of neuronal mechanisms in frontal language cortex and evidences that both consecutive and parallel processing of these speech signs occur in neuronal activity of this area.

Frontal Lobe↗

PubMed2006

Cerebral state monitor, a new small handheld EEG monitor for determining depth of anaesthesia: a clinical comparison with the bispectral index during day-surgery.

BACKGROUND AND OBJECTIVE: The cerebral state index (CSI) derived from a new small handheld electroencephalogram monitor was studied during routine day surgical anaesthesia titrated according to the bispectral index (BIS). The objective was to determine the degree of agreement between the two monitors. METHODS: Anaesthesia was induced with propofol and fentanyl (0.1 mg) in 38 patients undergoing general anaesthesia for routine day-surgery. Maintenance anaesthesia (sevoflurane (20/38), desflurane (10/38) or propofol (8/38)) titrated by BIS XP (Aspect Medical, Natwick, MA, USA) and BIS and CSI (cerebral State Monitor, Danmeter; Odense, Denmark) index values were recorded every minute. No patient received muscle relaxation. Observer's Assessment of Alertness/Sedation rating scale was used to assess level of sedation. RESULTS: Pair-wise recordings (914) of CSI and BIS were collected. The indices showed similar pattern and decreased with increasing level of sedation, however with large ranges for each level of sedation. Median indices were similar during surgery (BIS: 50 (14-89); CSI: 51 (7-88)) and both indices increased (P 20% from BIS-index in 24% of readings, and on rare occasions CSI indices deviated >100% from the BIS reading. When BIS < 40, CSI decreased slower than BIS and with wider spreading. CONCLUSIONS: When used for day-surgery anaesthesia without muscle relaxation, CSI and BIS show similar patterns and numerical values but with the incidence of occasionally large discrepancies between pair-wise readings. Which monitor is the more dependable remains to be established and cannot be implied from this initial explorative study.

Adult↗

PubMed2026

A de novo algorithm for allele reconstruction from Oxford nanopore amplicon reads, with application to CYP2D6.

MOTIVATION: The Oxford Nanopore Technologies' sequencing platform offers a path towards bedside genomics, producing long reads that can completely cover a gene of interest, and detect any known or novel variant the gene contains. However, the analysis of these long reads to identify actionable genotypes remains challenging and typically requires customization depending on the target gene. RESULTS: Here, we describe a generic algorithm to accurately reconstruct allele sequences derived from long-reads of amplicon-based data. Rather than calling variants directly from these long-reads, our method takes a "sequence-first" approach, performing an unbiased reconstruction of the underlying amplicon sequences to generate high-confidence reconstructed allele sequences. This is done without user input of the target gene, allowing for any source amplicon to be reconstructed. These high-confidence reconstructed allele sequences are then compared to the genomic reference sequence of the gene to infer the specific diplotype present in the sample. This approach is agnostic towards the number of genes and alleles present and readily detects novel variants. We demonstrate our approach using three independent data sets for CYP2D6, a diverse and complex gene with over 175 known alleles of clinical significance. We show how our approach can accurately recover validated CYP2D6 diplotypes from 20 Coriell samples covering 14 distinct alleles, using different amplicons, flow cell versions, and depths. This includes inferring occurrences of allele duplication events from relative abundances of each allele, a critical factor for ascribing functional effects to a diplotype. Further, we demonstrate our approach's utility for other genomic regions, including HLA. AVAILABILITY: Custom code is available at the following GitHub repository, along with instructions for use and test data: https://github.com/scottdbrown/allele-reconstruction-long-read-amplicon-data. A snapshot of the code at the time of publication is available on Zenodo.org; doi 10.5281/zenodo.19716004. Raw .fastq sequence data for our three sequencing runs is available at the SRA under Bioproject PRJNA1357883 (https://www.ncbi.nlm.nih.gov/bioproject/1357883).

Alleles↗

PubMed1992

Human papillomavirus.

In the past year, new data have been published on the molecular biology of human papillomavirus infections and their relationship to cervical neoplasia. As molecular techniques have become more sophisticated and as the molecular knowledge of human papilloma-virus infections has been pursued in greater depth, it is increasingly apparent that this human tumor DNA virus is similar to a number of other oncogenic DNA viruses that have been described and well studied. These viruses appear to act through a common pathway of producing oncogenic proteins that interfere with key signalling elements that normally control the process of cell division. With a better mechanistic knowledge, it should be possible to design new therapeutic approaches to treating human papillomavirus-associated disease that are directed toward specific cellular events such as turning off the production of E6 and E7 proteins or restoring the activity of pRB or p53. Increased attention has also been turned to immunologic aspects of HPV infections, and a number of groups are eagerly pursuing the possibility of using simple office-based procedures to detect specific proteins encoded for by the human papillomavirus open reading frames in an attempt to determine who has been infected, is actively infected, and has proteins being produced that are indicative of neoplasia. From the clinical point of view, the use of outpatient excisional techniques such as the loop electrosurgical excision procedure is rapidly supplanting ablative techniques because of their superior ability to identify early invasive carcinomas and adenocarcinomas in situ that have not been detected by colposcopy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed2004

Use of water-equivalent plastic scintillator for intravascular brachytherapy dosimetry.

Beta irradiation has recently been investigated as a possible technique for the prevention of restenosis in intravascular brachytherapy after balloon dilatation or stent implantation. Present methods of beta radiation dosimetry are primarily conducted using radiochromic film. These film dosimeters exhibit limited sensitivity and their characteristics differ from those of tissue, therefore the dose measurement readings require correction factors to be applied. In this work a novel, mini-size (2 mm diameter by 5 mm long) dosimeter element fabricated from Organic Plastic Scintillator (OPS) material was employed. Scintillation photon detection is accomplished using a precision photodiode and innovative signal amplification and processing techniques, rather than traditional photomultiplier tube methods. A significant improvement in signal to noise ratio, dynamic range and stability is achieved using this set-up. In addition, use of the non-saturating organic plastic scintillator material as the detector enables the dosimeter to measure beta radiation at very close distances to the source. In this work the plastic scintillators have been used to measure beta radiation dose at distances of less than 1 mm from an Sr-90 cardiovascular brachytherapy source having an activity of about 2.1 GBq beta radiation levels for both depth-distance and longitudinal profile of the source pellet chain, both in air and in liquid water, are measured using this system. The data obtained is compared with results from Monte Carlo simulation technique (MCNP 4B). Plastic scintillator dosimeter elements, when used in conjunction with photodiode detectors may prove to be useful dosimeters for cardiovascular brachytherapy beta sources, or other applications where precise near-source field dosimetry is required. The system described is particularly useful where measurement of actual dose rate in real time, a high level of stability and repeatability, portability, and immediate access to results are prime requirements.

Beta Particles↗

PubMed1999

Neuropsychological, learning and psychosocial profile of primary school aged children with the velo-cardio-facial syndrome (22q11 deletion): evidence for a nonverbal learning disability?

In this exploratory study, the neuropsychological and learning profile of nine primary school age children with velo-cardio-facial syndrome (VCFS) was studied by systematic neuropsychological testing. In five out of nine children, the following profile was found: a VIQ-PIQ discrepancy (in favor of the VIQ), significantly better scores (.05 level) for reading (decoding) and spelling compared to arithmetic, deficient tactile-perceptual skills (difficulties mainly on the left side of the body), weak but not deficient visual-perceptual abilities, deficient visual-spatial skills, extremely poor psychomotor skills (gross motor skills more deficient than fine motor skills), problems with processing of new and complex material, poor visual attention, good auditory memory and relatively good language skills. These findings correspond to the pattern of neuropsychological assets and deficits that has been described for the syndrome of nonverbal learning disabilities (NLD) (Rourke, 1987, 1988, 1989, 1995). The psychosocial profile of all nine children with VCFS also correspond to that of children with NLD. Further studies on the relationship between cognitive function, behavior, psychiatric disorder and abnormalities in brain anatomy in young people with VCFS will be needed. In clinical practice, it is worthwhile exploring in greater depth the neuropsychological functions of children with VCFS to rule out NLD, since they may benefit from specific remediation following the learning principles of the NLD-treatment.

Attention↗

PubMed1999

Progression of myopia in Hong Kong Chinese schoolchildren is slowed by wearing progressive lenses.

PURPOSE: In Chinese societies, primary and secondary schoolchildren perform large amounts of reading and homework and thus spend long periods performing near work during their growth years. Progressive lenses, which can permit a focused retinal image at distance, intermediate, and near, without accommodation, may slow the development of myopia. This paper reports results of a 2-year longitudinal study to examine the effects of progressive lenses on myopia progression in myopic Chinese children; these children were aged between 9 and 12 years at the beginning of the study. METHODS: Prestudy vision screening tests and five examinations, which included noncycloplegic refraction, were conducted at half-yearly intervals. Of those who completed the study, 32 children wore single vision (SV) lenses (the SV group) and 36 wore progressive lenses; of the latter, 22 wore a +1.50 D addition (the P1 group) and 14 wore a +2.00 D addition (the P2 group). Refractive error, corneal curvature, axial length, vitreous depth, and intraocular pressure were measured at every examination. Height was measured as an index of general growth. RESULTS: Progressive lenses significantly retarded the progression of the myopia in these children. Initially, the mean refractive error of the SV group was -3.67 D, of the P1 group was -3.73 D, and of the P2 group was -3.67 D. The mean myopic progressions over the 2 years of the study were -1.23, -0.76, and -0.66 D for the SV, P1, and P2 groups, respectively. CONCLUSION: Progressive lenses reduce the progression of myopia. It may be that the interaction of the progressive lenses with the accommodation system is the cause of this reduction in myopia progression because the +2.00 D addition appeared more effective than the +1.50 D addition in slowing the progression.

Child↗

PubMed2003

Influence of operator experience on the performance of ultrasound biometry compared to optical biometry before cataract surgery.

PURPOSE: To compare measurements performed with the IOLMaster (Carl Zeiss, Meditec AG) with those obtained by applanation ultrasound (US) and manual keratometry and to evaluate the effect of operator experience on US biometry. SETTING: Department of Ophthalmology, University of Vienna, Vienna, Austria. METHODS: The axial length (696 eyes) and anterior chamber depth (ACD) (462 eyes) were measured in 377 patients with cataract using the IOLMaster and applanation US. To assess the effect of operator experience on the biometric results, the operators were divided into 2 groups: experienced and less experienced in performing US biometry. The difference in measurements between the methods and the variability of the difference were compared between the 2 groups. RESULTS: Applanation US measured axial length and ACD shorter than the IOLMaster; the mean numerical difference was 0.13 mm and 0.19 mm, respectively (P<.01). For axial length, the absolute difference was smaller with experienced operators than with less experienced operators (0.15 mm versus 0.22 mm) (P<.01). For ACD, experienced operators obtained a smaller difference between measurement techniques (0.21 mm versus 0.29 mm; P<.05). CONCLUSIONS: Experienced US operators had less difference and lower variability in the difference between applanation US and IOLMaster readings for axial length and ACD measurements. The noncontact optical method, which is essentially operator independent, gave significantly more reliable biometry before cataract surgery, especially in the case of less experienced operators.

Adult↗

PubMed2002

Investigation of the use of MOSFET for clinical IMRT dosimetric verification.

(Received 22 October 2001; accepted for publication 26 March 2002; published 22 May 2002) With advanced conformal radiotherapy using intensity modulated beams, it is important to have radiation dose verification measurements prior to treatment. Metal oxide semiconductor field effect transistors (MOSFET) have the advantage of a faster and simpler reading procedure compared to thermoluminescent dosimeters (TLD), and with the commercial MOSFET system, multiple detectors can be used simultaneously. In addition, the small size of the detector could be advantageous, especially for point dose measurements in small homogeneous dose regions. To evaluate the feasibility of MOSFET for routine IMRT dosimetry, a comprehensive set of experiments has been conducted, to investigate the stability, linearity, energy, and angular dependence. For a period of two weeks, under a standard measurement setup, the measured dose standard deviation using the MOSFETs was +/- 0.015 Gy with the mean dose being 1.00 Gy. For a measured dose range of 0.3 Gy to 4.2 Gy, the MOSFETs present a linear response, with a linearity coefficient of 0.998. Under a 10 x 10 cm2 square field, the dose variations measured by the MOSFETs for every 10 degrees from 0 to 180 degrees is +/- 2.5%. The percent depth dose (PDD) measurements were used to verify the energy dependence. The measured PDD using the MOSFETs from 0.5 cm to 34 cm depth agreed to within +/- 3% when compared to that of the ionization chamber. For IMRT dose verification, two special phantoms were designed. One is a solid water slab with 81 possible MOSFET placement holes, and another is a cylindrical phantom with 48 placement holes. For each IMRT phantom verification, an ionization chamber and 3 to 5 MOSFETs were used to measure multiple point doses at different locations. Preliminary results show that the agreement between dose measured by MOSFET and that calculated by Corvus is within 5% error, while the agreement between ionization chamber measurement and the calculation is within 3% error. In conclusion, MOSFET detectors are suitable for routine IMRT dose verification.

Algorithms↗

PubMed2006

Performance of AEP Monitor/2-derived composite index as an indicator for depth of sedation with midazolam and alfentanil during gastrointestinal endoscopy.

BACKGROUND AND OBJECTIVE: The A-Line auditory evoked potential index (AAI) (AEP Monitor/2, Danmeter A/S, Odense, Denmark) is a newly developed composite parameter representing the degree of hypnosis. We conducted a prospective, observational study to explore the performance and validity of the AAI during conventional sedation for gastrointestinal (GI) endoscopy. METHODS: Thirty adults of either sex, age <65, scheduled for combined oesophagogastroduodenoscopy (OGD) and colonoscopy under sedation with intravenous (i.v.) midazolam and alfentanil were enrolled. The sedative end-point was set at the Observer's Assessment of Alertness/Sedation (OAA/S) score less than 4. An AEP Monitor/2 was used in all patients. AAI, sedation scores, heart rate (HR), blood pressure (BP) and SPO2 were recorded every 2 min up to the end of the procedure. Receiver operator characteristic analysis was used to test validity and to select optimal sedation. RESULTS: There was a significantly positive correlation between AAI and OAA/S scores (rho = 0.886; P < 0.001). The AAI also showed significant differences between subsequent levels of sedation scores (P < 0.001). AAI greater than 54 indicated fully awake or minimal sedation and values between 54 and 42 were suggestive of moderate sedation. Values between 42 and 34 were associated with moderate to deep sedation and readings below 34 were associated with deep sedation. The relative risk of SPO2 < 95% for OAA/S = 2 compared with 3 was 15.98 (95% confidence interval (CI): 3.94-64.81). CONCLUSIONS: AAI is an effective tool for monitoring sedation during GI endoscopy induced by i.v. midazolam and alfentanil.

Adult↗

PubMed2000

Additional clinical observations utilizing bispectral analysis.

Additional observations were made in the use of the bispectral (BIS) index with the use of ketamine and in performing general anesthesia without the use of local anesthesia in nonintubated patients. Twenty-five subjects undergoing extraction procedures in an outpatient setting were analyzed using bispectral analysis with ketamine and midazolam. Despite repeated injections of midazolam during the procedure, only transient decreases of the BIS occurred to the 80s, with a low value of 77 in all but 1 patient where ketamine was used. In comparison, values in the 50-70 range are typically seen immediately after the administration of sedative doses of midazolam, propofol, or methohexital. In the second study, once propofol anesthesia was initiated, BIS readings in the 30s were commonly seen in patients during their procedure. The lowest BIS level observed was 18. Bispectral analysis was useful to trend the present anesthetic state and adjust the dose of propofol accordingly. In no case was laryngospasm or total airway obstruction observed. In 1 case, partial airway obstruction secondary to retro-positioning of the tongue occurred with a subsequent decrease in oxygen saturation to 89%. This was rectified by repositioning the patient to alleviate the obstruction. Consistent with previous studies utilizing ketamine, BIS values are consistently higher when compared with other hypnotic agents. With the subsequent injection of midazolam, the BIS level did not decrease to anticipated levels. In the final study reviewed, when local anesthesia was not used during general anesthesia, bispectral analysis was a useful adjunct in helping maintain a steady state of general anesthesia in nonintubated patients undergoing third molar extractions. Bispectral analysis offers additional information on the depth of the hypnotic state and is useful in helping control the depth of anesthesia. A limitation of the index includes the inability to titrate the level of sedation induced by hypnotic agents such as midazolam when ketamine is concomitantly administered.

Airway Obstruction↗

PubMed1993

[Contrast sensitivity and defocus curve with various bifocal-IOL].

Simultaneous vision, the basic principle of all bifocal intraocular lenses (IOLs), provides increased depth of focus but also causes a loss in contrast. We therefore measured contrast acuity (CA) (Regan Charts) and the defocus curve at different pupil sizes in 14 patients with a TRUE VISTA bifocal IOL (TV) (Storz Co.), 10 patients with a 3M diffractive bifocal IOL (3M) (3M Co.) and 9 patients with a Nordan Aspheric Varifocal Silicone IOL (VF) (Wright Medical Inc.). CA at distance focus was best with VF; next was TV, and 3M showed the lowest values. At near focus, CA was best with 3M; next was TV, and VF showed the lowest values. Differences between VF and 3M were significant (P = 0.05; t-test). CA at near focus was significantly lower than at distance focus with TV and VF (TV: P = 0.0001; VF: P = 0.005). Pseudoaccommodation was 4.5 D with TV and 3M and 3D with VF. In conclusion, distance CA was best with VF but pseudoaccommodation was not sufficient for reading. Near CA was best with 3M while distance CA was somewhat reduced. TV showed good distance CA while near CA was still sufficient. TV therefore seems to provide a good compromise.

Accommodation, Ocular↗

PubMed2004

A new approach in dose measurement and error analysis for narrow photon beams (beamlets) shaped by different multileaf collimators using a small detector.

Dose measurement for narrow stereotactic beams and intensity modulation radiotherapy beamlets is difficult and error-prone due to the lack of lateral electron equilibrium. A small detector position error and finite sensitive volume as well as the nonfocus collimation could result in considerable (> 10%) measurement errors. A new method is introduced here to measure the dose and error components so that the accuracy and precision of the dose measurement can be improved. Based on superposition principle, we can create exactly the small field of interest by subtraction of a reference open field (O-field) and two strip fields (S-fields) from the sum of four quadrant fields (Q-fields). The position effect on the dose measurement is determined by the standard deviation of the four Q-field readings. The collimator leaf-edge effect (LEE) is quantified by the difference between the readings of the two S-fields using a detector that has very small sensitive volume. The detector-volume effect can be analytically estimated from the integrals of the dose distributions of the two S-fields over the detector volume. Using a pinpoint ion chamber (PTW N31006) and a stereotactic silicon diode detector (Scanditronix, DEB050), we have measured scatter factors (SF) and tissue-maximum ratios for 6-MV x-ray fields with sizes of 3 x 3 and 6 x 6 mm2 shaped by a BrainLAB micromultileaf collimator (microMLC) (M3), 4.4 x 4.4 and 8.8 x 8.8 mm2 shaped by a 3DLine double-focus MLC, and 5 x 5 and 10 x 10 mm2 by a Varian Millennium MLC. Our experimental results demonstrate that the large errors are often caused by a small setup error or measuring point displacement from the central ray of the beam. The LEE is almost independent of the depth but closely related to the field size and the type of MLC. The volume effect becomes significant when the detector diameter is comparable to the half size of the small fields. Application of the new method using different detectors had achieved less than 8.3% total experiment error for all of the small fields of interest except for the SF of the 3 x 3 mm2 field from the pinpoint ion chamber that has 15% volume effect. Importantly, the new method using a solid water phantom is clinically convenient and highly reproducible.

Algorithms↗

PubMed1998

Skin to cervical epidural space distances as read from magnetic resonance imaging films: consideration of the "hump pad.".

STUDY OBJECTIVE: To measure the distances from the skin to the epidural space (DSES) of the lower cervical and upper thoracic intervertebral spaces. DESIGN: Retrospective review of films of the cervical spine as obtained by magnetic resonance imaging (MRI). SETTING: Health care facility that provides diagnosis and treatment of patients with chronic pain. MEASUREMENTS AND MAIN RESULTS: MRI sagittal films of 100 patients, who had diagnostic studies for chronic headaches and cervicobrachial radiculopathy, were reviewed. Measurements were made of DSES, the dural sac, and the spinal cord by centimeter ruler. Estimates were also made of the width of the epidural space by measuring the distance from the ligamentum flavum to the dural sac. The longest DSES were noted at C6-7 and C7-T1 levels, with a mean of 5.7 cm, but they decreased to a mean of 5.4 cm at the T1-2, and to 4. 7 cm at the T2-3 intervertebral spaces. One of the major factors in this variability was the presence of an accumulation of fatty tissue along the lower cervical and upper thoracic area, which the authors named the "hump pad." This accumulation appears to be thicker in obese patients, with a slight correlation coefficient with the patient's weight. The distances from ligamentum flavum to dural sac, representing the depth of the epidural space, averaged 0.3 cm, 0.4 cm, 0.5 cm, and 0.4 cm, respectively. CONCLUSIONS: In the cervical spine, DSES varies from space to space. In obese individuals, the fat pad may increase DSES at the lower cervical intervertebral spaces. The longest mean distances from the ligamentum flavum to the dural sac and to the spinal cord were found at the T1-2 and T2-3 levels, precisely where DSES is shorter. All things being equal, the upper thoracic intervertebral spaces appeared to provide a greater margin of safety for insertion of epidural catheters to treat cervicobrachial radiculopathies.

Adipose Tissue↗

PubMed1987

Application of cancer prevention knowledge: a longitudinal follow-up study of medical students.

Measuring the clinical application of knowledge and skills acquired in specific medical school courses is a critical part of curriculum evaluation. Second-year Cancer Prevention Course (CPC) students and a comparison group were surveyed by questionnaires, cognitively tested, and a subsample participated in in-depth interviews. The 6-month and 18-month follow-up interviews indicated that more CPC students practiced prevention in their clinical rotations than did the comparison group. Direct, one-on-one access to patients during clinical training was an important mediating factor in the practice of prevention skills. In addition, a behavioral intent inventory showed that CPC students, in their future careers, intend to perform certain specific cancer prevention activities more than others. Long-term retained knowledge (75% correct) stabilized at levels significantly higher (p less than .001) than baseline test scores prior to the Cancer Prevention Course. At the time of the two follow-up exams of cognitive knowledge, the comparison group of students was able to do no better than had the CPC students at baseline before the course. Positive beliefs about cancer prevention improved over the study period. More than twice as many cancer course students attended subsequent optional lectures and reported optional reading on cancer prevention topics than did the comparison group. Overall, the study showed a lasting effect of the elective course in cancer prevention, in terms of tested knowledge, and self-reported measures of attitudes, beliefs, practice of prevention in clinical rotations, and intent to apply prevention in future practice.

Curriculum↗

PubMed2000

Two new microscopical variants of thermomechanical modulation: scanning thermal expansion microscopy and dynamic localized thermomechanical analysis

We describe two ways in which thermomechanical modulation may be used in conjunction with scanning thermal microscopy, in order to distinguish between different components of an inhomogeneous sample. The sample is subjected to a modulated mechanical stress, and the heating is supplied locally by the probe itself. Scanning thermal expansion microscopy is an imaging mode, in which an imposed localized temperature modulation is used to generate thermal expansion, which in turn produces mechanical strain and gives thermal expansion contrast images. We present results using two types of active thermal probe. For polymer/resin samples, the depth of material contributing to the measured thermal expansion is typically a few micrometres. Under certain conditions we observe a reversal in contrast as the frequency of the temperature modulation is increased. In dynamic localized thermomechanical analysis, the modulated stress is applied directly, and accompanied by a localized temperature change, as used in other forms of localized thermal analysis. The resulting modulated lateral force signals are obtained. The glass transition of polystyrene is detected, and shows a significant variation with frequency. The amplitude or phase signal may be used to obtain image contrast for inhomogeneous samples.

Journal Article↗