What is below the support layer affects carbon nanotube growth: an iron catalyst reservoir yields taller nanotube carpets.

Here we demonstrate an approach to enhance the growth of vertically aligned carbon nanotubes (CNTs) by including a catalyst reservoir underneath the thin-film alumina catalyst underlayer. This reservoir led to enhanced CNT growth due to the migration of catalytic material from below the underlayer up to the surface through alumina pinholes during processing. This led to the formation of large Fe particles, which in turn influenced the morphology evolution of the catalytic iron surface layer through Ostwald ripening. With inclusion of this catalyst reservoir, we observed CNT growth up to 100% taller than that observed without the catalyst reservoir consistently across a wide range of annealing and growth durations. Imaging studies of catalyst layers both for different annealing times and for different alumina support layer thicknesses demonstrate that the surface exposure of metal from the reservoir leads to an active population of smaller catalyst particles upon annealing as opposed to a bimodal catalyst size distribution that appears without inclusion of a reservoir. Overall, the mechanism for growth enhancement we present here demonstrates a new route to engineering efficient catalyst structures to overcome the limitations of CNT growth processes.

End-of-life decision making by adolescents, parents, and healthcare providers in pediatric oncology: research to evidence-based practice guidelines.

Participating in end-of-life decisions is life altering for adolescents with incurable cancer, their families, and their healthcare providers. However, no empirically developed and validated guidelines to assist patients, parents, and healthcare providers in making these decisions exist. The purpose of the work reported here was to use three sources (the findings of three studies on decision making in pediatric oncology, published literature, and recommendations from professional associations) to develop guidelines for end-of-life decision making in pediatric oncology. The study designs include a retrospective, descriptive design (Study 1); a prospective, descriptive design (Study 2); and a cross-sectional, descriptive design (Study 3). Settings for the pediatric oncology studies included a pediatric catastrophic illness research hospital located in the Midsouth (Studies 1 and 2); and that setting plus a children's hospital in Australia and one in Hong Kong (Study 3). Study samples included 39 guardians and 21 healthcare providers (Study 1); 52 parents, 10 adolescents, and 22 physicians (Study 2); and 43 parents (Study 3). All participants in the studies responded to six open-ended questions. A semantic content analysis technique was used to analyze all interview data. Four nurses independently coded each interview; interrater reliability per code ranged from 68% to 100% across studies. The most frequently reported influencing factors were "information on the health and disease status of the patient," "all curative options having been attempted," "trusting the healthcare team," and "feeling support from the healthcare provider." The agreement across studies regarding influencing factors provides the basis for the research-based guidelines for end-of-life decision making in pediatric oncology. The guidelines offer assistance with end-of-life decision making in a structured manner that can be formally evaluated and individualized to meet patient and family needs.

Assessment and management of pain in the critically ill pediatric patient.

Alhough considerable progress has been made in the past decade in the study of pain in children, numerous myths, inadequate assessment, and insufficient knowledge of available treatment continue to contribute to the lack of effective management of children's pain. Clinicians who lack knowledge have misconceptions about pain contribute more to the problem than to the problem's solution. Adequate analgesia is to be provided to even the sickest child the medications, techniques, and approaches reviewed here.

An international feasibility study of parental decision making in pediatric oncology.

PURPOSE/OBJECTIVES: To describe parental decision making about treatment options for children with cancer and determine the feasibility of a similar but larger international study. DESIGN: Exploratory. SETTINGS: A pediatric catastrophic illness research hospital in the United States and children's hospitals in Australia and Hong Kong. SAMPLE: A convenience sample of 43 parents (5 fathers and 38 mothers ages 23-59 years). METHODS: Six open-ended interview questions posed to parents during private individual interviews. Content analysis techniques were used. MAIN RESEARCH VARIABLES: Parental perceptions of (a) factors considered in the decision-making process, (b) behaviors of healthcare professionals that affected the process, and (c) satisfaction with the process. Feasibility of a larger study was estimated by considering ease of access to parents, number of refusals to participate, understanding of the interview questions, and level of interest at each setting. FINDINGS: Access to parents was possible at all sites. Refusal to participate was reported only at the U.S. site. Certain factors (e.g., getting information from the healthcare team, trusting staff) were important to all parents considering end-of-life decisions. Site-specific factors included considering alternative therapies (at the Australian site) and strengthening faith (at the U.S. site). CONCLUSIONS: A larger international study of parental decision making is feasible. Sufficient similarities in parental decision making exist across these sites to justify future efforts to identify universal decision-making factors that, in conjunction with site-specific differences, could be helpful in developing guidelines for healthcare professionals who assist parents in making treatment-related decisions for a sick child.

Biliary symptom scoring as a method of selecting patients for cholecystectomy.

BACKGROUND: A group of patients referred to general surgeons for the treatment of gall bladder stones was studied to evaluate the role of a numerical symptom scoring system (biliary symptom score (BSS)) as a tool to improve the assessment of patients and reduce the incidence of post-cholecystectomy symptoms. METHODS: Fifty-seven patients with gallstones and abdominal symptoms referred to general surgeons were studied. All patients were interviewed by a surgeon in training independently from the treating surgeon and given a subjective and objective assessment of their symptoms (using the BSS); they were then categorized into biliary, non-biliary and possible biliary groups. The results of the interviews remained unknown to the treating surgeon throughout the period of study. The symptom status of all patients was reevaluated 6-12 months later; the patients' outcome was compared with their initial objective score and the subjective assessment by the independent assessor and with the treating surgeon's initial assessment. RESULTS: Fifty-one patients were able to be analysed. Subjective independent assessment and BSS were closely correlated (phi = 0.89). Use of the BSS improved the accuracy of the independent assessor from 53% (subjective assessment) to 69%, but this was at the cost of recommending cholecystectomy in 30% of the patients with non-biliary symptoms. The accuracy of experienced consultant general surgeons was 98% with a single case of post-cholecystectomy syndrome (2%). CONCLUSION: Numerical BSS improves diagnostic accuracy for a surgeon in training by reducing the number of patients classified with possible biliary symptoms, but it remains significantly less accurate than the subjective clinical assessment of an experienced consultant general surgeon.

The future of infant categorization research: a process-oriented approach.

We call for a shift from a content-oriented approach to a process-oriented approach to the study of categorization in infancy. Although gains have been made in our understanding of infant categorization by evaluating the categories to which infants respond, further understanding of infant categorization, and how categorization changes with development, requires that we more directly assess infants' category formation. We argue that two directions for future research will continue to enhance our understanding of categorization in infancy (and beyond). First, contextual variations (e.g., the effects of task, stimuli, and other factors) on infants' categorization must be better understood. Second, we must more directly evaluate the kinds of information infants use when forming categories, as well as how their use of such information changes with age, task, and so forth. We argue that these two foci will provide clearer understanding of the origins and early development of categorization.

NCCN Practice Guidelines for Cancer Pain.

The overall approach to pain management encompassed in these guidelines is comprehensive. It is based on objective pain assessments, utilizes both pharmacologic and nonpharmacologic interventions, and requires continual reevaluation of the patient. The NCCN Cancer Pain Practice Guidelines Panel believes that cancer pain can be well controlled in the vast majority of patients if the algorithms presented are systematically applied, carefully monitored, and tailored to the needs of the individual patient.

The effects of norethisterone on endometrial abnormalities identified by transvaginal ultrasound screening of healthy post-menopausal women on tamoxifen or placebo.

Tamoxifen (tam) is used extensively for treatment of patients with breast cancer and is being evaluated for chemoprevention in healthy women. It has, however, been reported to increase the risk of endometrial cancer in post-menopausal women, probably by an oestrogenic effect on the endometrium. It also causes endometrial cysts and polyps. The aims of this study were to identify the incidence of endometrial thickening, polyps and cysts by transvaginal ultrasound (TVUS) screening of a population of post-menopausal healthy women in the Royal Marsden tamoxifen chemoprevention trial and to evaluate the possible benefit from the use of intermittent norethisterone (NE) in women with persistent changes. Since 1990, we have undertaken regular TVUS, using an endovaginal B mode probe, of the 463 post-menopausal women in the trial randomized to tam (20 mg day(-1)) or placebo (plac), without breaking the randomization code. Endometrial thickening (ET) was defined as > or = 8 mm at the widest point across the myometrial cavity in the longitudinal plane, including any stromal changes. Cystic changes were defined as more than one hypoechogenic area > 1 mm. Polyps were identified using saline hydrosonography. Oral NE (2.5 mg day(-1)) was used for 21 days out of 28 for three consecutive cycles by women with persistent endometrium > or = 8 mm, including cystic and polypoid changes. TVUS was repeated after the three courses to evaluate any change caused by NE and endometrial biopsies, including hysteroscopy, was performed on those women with persistent abnormalities. A persistent ET > or = 8 mm was identified in 56 (24%) of the 235 women on tamoxifen compared with only 5 (2%) of 228 women on placebo (P <0.0005). Stromal changes, including cysts, were detected in 36 (15%) and polyps in 26 (11%) of the women on tamoxifen compared with only two (< 1%) of the women on placebo (P << 0.0005). After 3 months of cyclical norethisterone, 39 of 47 women (83%) on tamoxifen had persistent ultrasound changes. However, 45 (96%) had a progesterone withdrawal bleed. Hysteroscopy was performed in 39 women on tamoxifen (28 endometrial biopsy, 15 polypectomy), five of whom had histological evidence of a proliferative endometrium and a further three had an atypical hyperplastic endometrium (one of whom had a focus of invasive carcinoma). The cysts and polyps which were detected in women on tam could not be reversed by NE and were presumably stromal and not of malignant risk. However, 96% of the women had withdrawal NE bleeding, indicating an oestrogenically primed endometrium which could be a mechanism for an increased risk of endometrial cancer. Further studies are required to ascertain whether a progestin would protect against this risk. As in other studies, these results indicate that any increased risk of endometrial cancer caused by tamoxifen is low, and that TVUS screening is probably not justified for asymptomatic women on tamoxifen.

Decision making by parents and healthcare professionals when considering continued care for pediatric patients with cancer.

PURPOSE/OBJECTIVES: To better define the treatment-related decisions considered most difficult by parents of pediatric patients with cancer and the factors that influenced their final decisions. DESIGN: Retrospective-descriptive design. SETTING: Pediatric oncology institution in the mid-southern region on the United States. SAMPLE: 39 parents representing 37 of 83 eligible families, 16 attending physicians, three nurses, and two chaplains. METHODS: Parent participants responded by telephone to six open-ended interview questions and a 15-item questionnaire about factors that were important when making the decision to continue care. Healthcare professionals were interviewed face-to-face. MAIN RESEARCH VARIABLES: Most difficult treatment-related decisions; factors influencing decision making. FINDINGS: Parents reported 15 types of difficult decisions, the majority of which were made late in the course of treatment. Deciding between a phase I drug study or no further treatment (n = 14), maintaining or withdrawing life support (n = 11), and giving more chemotherapy or giving no further treatment (n = 8) were the most frequently reported difficult decisions. Parents rated "recommendations received from healthcare professionals" as the questionnaire factor most important in their decision making, and healthcare professionals rated "discussion with the family of the patient" as the most important factor. CONCLUSION: Parents of children or adolescents with cancer and their healthcare providers face difficult treatment-related decisions, many of which occur late in the course of treatment. Parents and healthcare professionals cite similar factors in their decision making but differ in their ratings of the factors' importance. For parents, the information and recommendations they receive from healthcare professionals figure most frequently and most importantly in their decision making. For healthcare professionals, the certainty that the patient will not get better and discussions with the patient's family figure most importantly in their decision making. Once parents conclude that their child can not get better, they are more likely to choose noncurative options such as choosing no further treatment or withdrawing life support. IMPLICATIONS FOR NURSING PRACTICE: Nurses can help determine what information parents need in their decision making. Particular attention must be given to ways to communicate the likelihood of the their child's survival.

By land or by sea: the role of perceptual similarity in infants' categorization of animals.

In 3 experiments, the authors used an object-examining task to investigate the role of perceptual similarity in infants' categorization. In Experiment 1, infants were familiarized with a set of either perceptually similar or perceptually variable exemplars from 1 category and tested with novel exemplars from both categories. Ten-month-olds did not respond to the category in either condition, and 13-month-olds responded categorically in both conditions but somewhat differently in the 2 conditions. Experiment 2 showed that when 10-month-olds were familiarized with similar exemplars but not with variable exemplars, they responded to the categorical distinction when given tests with typical exemplars. Experiment 3 established that 10-month-olds could differentiate among the exemplars. These results suggest that the perceptual similarity of the exemplars influences infants' recognition of categorical distinctions.

Distractibility in infancy: the effects of distractor characteristics and type of attention.

Two experiments investigated the role of distractor characteristics and type of object-directed attention on infants' distraction latencies during object exploration. In Experiment 1, 7- and 10-month-old infants' distraction latency was a function of both attention and the characteristics of the distractors. Infants took longer to turn toward distractors during focused object-directed attention than when engaged in more casual attention. In addition, their latencies were longer regardless of attention type when the distractors were unimodal (e.g., consisting of only a visual or an auditory component) than when they were bimodal (e.g., consisting of both auditory and visual components). Experiment 2 demonstrated that infants exhibit shorter distraction latencies toward complex than simple bimodal distractors. These results are discussed in the context of Allport's (1989) model of attention and suggest that infants' allocation of attentional resources, as measured by distraction latencies, is influenced both by the characteristics of the distractor and by the type of infants' object-directed attention.

MICs of rifampicin and chloramphenicol for mucoid Pseudomonas aeruginosa strains are lower when human lactoferrin is present.

MlCs of rifampicin and chloramphenicol for mucoid strains of Pseudomonas aeruginosa were lower in the presence of human lactoferrin (0.9 mg/mL, the concentration found in cystic fibrosis sputum) than in its absence. MICs for some strains were lowered to clinically achievable levels of the antibiotics, which is compatible with impressions of greater clinical efficacy in pseudomonas infections than would be predicted by standard sensitivity tests. The routine addition of lactoferrin to sensitivity media for testing of cystic fibrosis isolates may give more useful results than conventional tests as in-vivo conditions are more closely simulated.

The natural connection: the clinical nurse specialist and bedside nursing research.

The educational preparation and consistent clinical focus of CNSs position them ideally for conducting research at the bedside and helping staff nurses see the relevance of such research. Our research studies have identified a new category of clinical nursing research termed bedside nursing research. Like its parent category of clinical nursing research, the function of bedside nursing research is to generate new knowledge or validate and expand previously generated knowledge. Characteristics that distinguish bedside nursing research from other forms of clinical nursing research are: focus, idea stimulus and setting, originator of the research question, relationship with theory, sensitivity to changing technology in health care, and impact on nursing practice. To illustrate the nature and outcome of this type of research, we describe three bedside nursing research studies conducted by CNSs in a pediatric oncology setting. These studies assessed: (1) the effects of chest tube stripping on the incidence of pain, fever, and pulmonary complications; (2) the relative safety and efficacy of techniques for blood sampling from Hickman catheters; and (3) the effects of infusion method on quality and survival of transfused platelets. The impact of these studies of hospital practices is reviewed.

Measuring pain in pediatric oncology ICU patients.

Thirty patients (ages 5 to 13) hospitalized in a pediatric oncology intensive care unit (ICU) rated the presence and severity of their pain on the Faces Pain Scale (FPS) and the Poker Chip Tool (PCT). Parents independently rated the child's pain on these scales and each patient's nurse completed the Objective Pain Scale (OPS). Patients' ratings on the FPS correlated significantly with parents' ratings on this scale (tau = .48, P = .002) but not on the PCT (tau = .23, P = .16). Nurses' ratings on the OPS were moderately correlated with patients' FPS ratings (tau = .37, P = .02) but were only weakly associated with PCT ratings (tau = .27, P = .09). The majority of patients, parents, and nurses expressed a preference for the FPS over the PCT. The FPS appears to be a clinically useful and accurate approach for measuring the pain of pediatric oncology patients in an ICU but is limited to those who can participate in a self-report measurement.

Effects of gentamicin, neomycin and tobramycin on renal calcium and magnesium handling in two rat strains.

1. Standard renal clearance techniques were used to compare the acute effects of gentamicin, neomycin and tobramycin on renal calcium and magnesium handling in Sprague-Dawley and Fischer 344 rats. 2. Significant hypercalciuric and hypermagnesiuric responses to all three drugs (P < 0.01) were apparent within 30 min of the onset of drug infusion. 3. The magnitude of the acute hypercalciuric and hypermagnesiuric response to the three aminoglycosides was comparable. This contrasts with their nephrotoxic action where neomycin >> gentamicin > tobramycin. The magnitude of the acute physiological responses to these drugs do not therefore reflect their nephrotoxic potential. 4. Sprague-Dawley rats were at least as responsive as Fischer rats in their acute renal responses to gentamicin. If Fischer rats are more sensitive to aminoglycoside nephrotoxicity than Sprague-Dawley rats, this is not reflected in their acute responses to gentamicin.

Postoperative analgesia following thoracotomy in children: interpleural catheters.

The authors retrospectively review their experience in children with the latest addition to the postoperative analgesic armamentarium: interpleural analgesia (IPA). IPA was used in 14 children following thoracotomy. There were 9 boys and 5 girls. Patients varied in age from 2 months to 17 years 4 months (mean +/- SEM = 7.6 +/- 1.6 yr). Catheters were left in place from 10 to 72 hours (mean +/- SEM = 45.1 +/- 4.6 h). Four patients received intermittent bolus doses and 10 patients received a continuous infusion through the interpleural catheters. Adequate analgesia, as judged by both subjective responses (decreased irritability or complaints of pain) and by objective physiologic responses (decreased heart rate, respiratory rate, and systolic blood pressure), was achieved in 13 of 14 patients. Eight of the 14 children required no additional analgesic agents. One child received 2 doses of oral codeine and 4 patients received 2 to 3 doses of intravenous narcotic during IPA. IPA was not effective in one patient who required 6 doses of intravenous meperidine. Patients more than 10 years of age required significantly more (P < 0.05) intravenous narcotic supplementation than patients less than 10 years of age (1.60 +/- 0.50 v 0.14 +/- 0.11 mg meperidine/kg/d). No complications related to placement or subsequent use of IPA were identified in any of the patients. IPA provides effective postoperative analgesia following thoracotomy in children.

Chest tube stripping in pediatric oncology patients: an experimental study.

BACKGROUND: Stripping of chest tubes to promote drainage of the thorax of postthoracotomy patients has been routine practice, based on tradition. Recent published findings indicate that significant negative pressures are generated in the tube during stripping that could cause pain, bleeding and possible damage to the patient's lung tissue. OBJECTIVE: To determine whether pediatric oncology patients whose chest tubes were not stripped would differ in frequency of pain, fever or lung complications from patients who underwent routine tube stripping. METHODS: Data were collected at multiple points during the first 72-hour postoperative period from 16 patients assigned to the stripped or unstripped groups. Pain was measured by the Faces Pain Scale and the Visual Analogue Scale; temperature, by electronic thermometer; and lung complications, by stethoscope and radiographs. Both groups, which were comparable for age, primary diagnosis and prior history of lung problems, received identical supportive nursing and medical care, with the physicians blind to group assignment. RESULTS: The two groups did not differ significantly in frequency of pain, incidence of fever, breath sounds or radiographic findings across measurement points. A strong correlation was found between the pain scores using the two instruments. DISCUSSION: Patients whose tubes were not stripped did not have an increased risk of infection or lung complications. Study findings indicated that stripping did not increase the frequency of pain. CONCLUSIONS: Stripping of chest tubes as a routine postoperative measure is questioned.

Consumer illness careers: an investigation of allergy sufferers and their universe of medical choices.

The concept of the consumer illness career with a focus on allergies is introduced and developed by the authors in terms of a trajectory of five stages over time, the related product-service unities or constellations--including health care treatments and remedies--and various situational and trait factors that influence the course of a consumer's response to his or her disease. Next, they investigate the career's holistic nature and thematic content in an in-depth study of allergy sufferers. The study indicates that allergy sufferers engage ina wide range of strategic behaviors and choices associated with coping with their allergies, much of which can be captured in terms of patterned themes. Finally, the authors offer research, managerial, and public policy implications.

Continuous epidural anesthesia for postoperative analgesia in the pediatric oncology patient.

When compared with conventional techniques, epidural anesthesia not only provides improved analgesia, but also has several beneficial effects on the postoperative respiratory, cardiovascular, and metabolic status of the patient. Although the efficacy of this technique in children has been demonstrated, extensive experience in the pediatric oncology patient has not been previously reported. We retrospectively reviewed our 2-year experience with epidural analgesia and discuss the techniques involved in implementing this service for the pediatric oncology patient. An epidural catheter was successfully placed in 58 of 60 patients (97%) who ranged in age from 4 months to 19 years and in weight from 4.1 to 68 kg. Postoperative analgesia was provided by a continuous infusion of a bupivacaine/fentanyl mixture, supplemented with intermittent epidural fentanyl by bolus dose as needed. No complications related to epidural catheters were noted. Our review supports the efficacy of this technique for providing postoperative analgesia after various major surgical procedures in the pediatric oncology patient.