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Biomedical subjects

J Nanda

Publications and source records attributed to J Nanda.

15 recordsLinked to original sources

Unraveling internal structures of highly luminescent PbSe nanocrystallites using variable-energy synchrotron radiation photoelectron spectroscopy.

The internal structure of PbSe nanocrystals was deduced using synchrotron X-ray photoemission spectroscopy for three different sizes of nanocrystals. The photoemission data revealed the layered structure of PbSe nanocrystals with the crystalline PbSe core surrounded by a nonstoichiometric Pb(1-x)Se shell, finally passivated by a capping agent in the outermost layer. A detailed analysis of the experimental data yielded quantitative information on the thickness of three different layers, which is unavailable through any other technique; moreover, the overall sizes of the nanocrystals probed by transmission electron microscopy were in agreement with the corresponding quantity obtained in the present experiment. The present results provide a plausible explanation for the strong variation in the photoluminescence intensity with size observed for these nanocrystals.

Journal Article↗

Optical and magnetic properties of manganese-doped zinc sulfide nanoclusters.

We report the synthesis of fixed-size ZnS nanoclusters approximately 24 A in diameter with varying manganese concentrations. Various samples of Zn1-x MnxS, with x = 0, 0.02, 0.055, 0.09, and 0.13, have been prepared and characterized using X-ray diffraction, energy-dispersive analysis of X-rays, UV absorption, fluorescence emission and excitation, electron paramagnetic resonance (EPR), and magnetic susceptibility measurements. The manganese ions are found to substitute Zn randomly without giving rise to any clustering of Mn sites, as seen from EPR and magnetic susceptibility results. Our studies reveal that the band gap of the doped nanoclusters passes through a maximum as the manganese concentration is varied. Also, we observe orange emission from Mn2+ ions in the doped ZnS nanoclusters, apart from the blue emission characteristic of the ZnS defect states. The relative intensity of the orange emission compared with the blue varies with the manganese concentration in a nonmonotonic way. The inverse of susceptibility temperature plots can be plotted onto a universal curve by simple multiplicative constants, thus showing that the magnetic interactions between Mn2+ ions are weak.

Crystallization↗

Rural school nurses' asthma education needs.

School nurses play an important role in identifying children with asthma and providing care during school hours. Educational programs designed to improve nurses' asthma knowledge and practices have concentrated on urban settings. The purpose of this investigation was to determine asthma-related practices and educational needs of rural school nurses. A survey about asthma was mailed to school nurses in all counties of the state of Maryland and in Washington, D.C. Responses were compared between rural Maryland counties and counties from the remainder of Maryland and Washington, D.C. The survey addressed attitudes and beliefs, function and roles, medication administration, and educational needs about asthma. We found that rural nurses used peak flow meters less often to assess and monitor asthma, requested fewer referrals for asthma, had fewer interactions with health room assistants, and had reduced access to asthma educational resources. Also, they provided less asthma education in the schools than other school nurses. These results suggest a need for comprehensive asthma educational programs in rural areas that are based on national guidelines, and that address the unique needs of rural school nurses. These programs should also emphasize the need for open communication between rural school nurses, health room assistants, primary care providers, and parents/caregivers.

Adult↗

The effectiveness of the comprehensive coping strategy program on clinical outcomes in breast cancer autologous bone marrow transplantation.

Patients with breast cancer who undergo autologous bone marrow/peripheral blood stem cell transplantation (ABMT) cope not only with a life-threatening medical treatment, but also with multiple, interrelated symptoms including pain, fatigue, psychological distress, and nausea. The purpose of this study was to determine, in a randomized controlled clinical trial, whether a comprehensive coping strategy program (CCSP) was effective in significantly reducing pain, fatigue, psychological distress, and nausea in patients with breast cancer who underwent ABMT. The CCSP was composed of preparatory information, cognitive restructuring, and relaxation with guided imagery. Randomization placed 52 patients in the CCSP treatment group and 58 patients in the control group. The CCSP was found to be effective in significantly reducing nausea as well as nausea combined with fatigue 7 days after the ABMT when the side effects of treatment were most severe. These results are important given the high incidence of nausea and fatigue in the ABMT population. The CCSP-treated group experienced mild anxiety as compared with the control group who reported moderate anxiety. The greatest effectiveness of CCSP may correspond to the time of the greatest morbidity for patients with breast cancer who have undergone ABM.

Adaptation, Psychological↗

Effects of physical activity on preterm birth.

The authors conducted a cohort study of low income women to determine the effect of physical activity on the risk of preterm birth. Women were sampled prenatally from four clinic sites and were scheduled for delivery at the University of Maryland Medical Systems (UMMS). Women who delivered infants at UMMS but who had received no prenatal care were also eligible. Preterm delivery was defined as a delivery prior to 37 completed weeks gestation. After adjusting for confounders, the odds of preterm delivery were increased for women who climbed stairs > or = 10 times per day (odds ratio (OR) = 1.60, 95% confidence interval 1.05-2.46) and for women who engaged in purposive walking > or = 4 days per week (OR = 2.10, 95% CI 1.38-3.20). Leisure-time exercise (> or = 60 days in the first and second trimesters combined) had a protective effect on preterm delivery (OR = 0.51, 95% CI 0.27-0.95). Television viewing had a U-shaped relation with preterm delivery (ORs (95% CI): < 15 hours, 2.09 (1.21-3.61); 29-42 hours, 1.50 (0.84-2.67); > 42 hours, 3.05 (1.75-5.40)). While the results support current recommendations regarding leisure-time activities, activities of daily living appear to increase risk of preterm delivery among low income women. These findings and those for television watching warrant further investigation.

Activities of Daily Living↗

Consumer experiences and provider perceptions of the quality of primary care: implications for managed care.

BACKGROUND: The purpose of this study was to determine the extent to which consumer and provider reports of primary care differ according to particular characteristics of the primary care setting. METHODS: A random sample of consumers was surveyed by telephone in a defined geographic area of Washington, DC, to determine their experiences with care provided to a randomly chosen child. The primary care provider of each respondent was sent a parallel survey. Scores were obtained for each of two subdomains in the four cardinal primary care domains (first contact, longitudinality, comprehensiveness, and coordination) and for three related domains (family centeredness, community orientation, and cultural competence). Differences between settings that did or did not impose limitations on autonomy for referrals and between fee-for-service and capitated settings were ascertained. RESULTS: Both consumers and their providers in settings characterized by high degrees of limitation on physician autonomy or by capitation reported better first-contact accessibility and a greater range of services available than did consumers in settings with low degrees of limitation, or by fee-for-service reimbursements to physicians. Consumers but not providers reported better family centeredness in these settings. Most other differences favored these settings as well, but these were not consistently statistically significant for both providers and consumers in both types of settings. CONCLUSIONS: The quality of primary care services in different settings can be ascertained by using an instrument with demonstrated reliability and convergent validity. Although certain types of settings, in the particular geographic area studied, appear to perform better in several key aspects of the primary care, replication of the study in other areas would be useful judging the performance of the newer types of settings to be superior to more conventional care for general populations.

Child↗

Mechanisms for maternal age differences in birth weight.

The authors studied three hypothesized explanations for reduced birth weights of infants born to US adolescent mothers--social disadvantage, biologic immaturity, and unhealthy behaviors during pregnancy. A hierarchical regression analysis was pursued to evaluate these explanations using data from the National Longitudinal Study of Youth on 1,754 first births between 1979 and 1983 to women aged 14-25 years at the time of birth. The birth weights of infants of mothers aged 14-17, 18-19, and 20-23 years were 133, 54, and 88 g less than for infants of mothers aged 23-25. The regression results indicate that the reduced birth weights of infants born to young mothers, particularly women aged 14-17, were related to their disadvantaged social environment. When adjustment was made for poverty and minority status, there were no maternal age differences in birth weight. The reduced birth weights were not related to the young woman's health behaviors during pregnancy or her biologic characteristics. Ethnicity, poverty status, age at menarche, maternal height, net maternal weight gain, and smoking during pregnancy had an independent effect on birth weight in this sample of young women.

Adolescent↗

Young motherhood and infant hospitalization during the first year of life.

We studied the relationship of young maternal age with infant hospitalization using data from the National Longitudinal Survey of Youth for 3,130 infants born between 1979 and 1983 to mothers aged 14-25 years. Data on the mothers were first collected in 1979 and yearly thereafter. Data on their children were collected starting in 1982. Logistic regressions of infant hospitalization rates were estimated for first and second and higher births. The odds of infant hospitalization during the first year of life increased with decreasing maternal age, even with adjustment for sociodemographic characteristics, preventive health-care practices, and newborn health status, factors hypothesized to explain the maternal age effect. The maternal age relationship with hospitalization differed by birth order; among second and higher births, the odds of hospitalization was increased only for infants of mothers aged 20-22 years. Male infants, infants with a first well-baby visit after the first month of life, with birth weights between 1501 and 2500 g, and with nursery stays longer than 1 week also had increased odds of hospitalization. Ethnicity, grandmother's education, poverty status, mother's school enrollment, and family composition were not related to the odds of hospitalization, nor was smoking during pregnancy when adjustment was made for birth weight and length of nursery stay.

Adolescent↗

Primary care residency programme evaluation: an analysis of three resident cohorts.

The purpose of this study was to conduct a longitudinal evaluation of a university primary care (PC) medical residency programme and use the results to plan for future curriculum development. Overall performance and the ambulatory medical care of three consecutive resident cohorts training from 1982 to 1987 was assessed by attending physicians. PC residents' performance in ambulatory continuity practice was also compared to that of traditional residents' performance in 1985-86. The scoring profile of primary care attendings was compared to that of other attendings. Residents received lowest scores in diagnostic evaluation, leadership and administration. Their best evaluations were in medical care, personal attributes and communication. Two of the three primary care cohorts received lower medical care scores in ambulatory continuity practice compared to other rotations, but had higher overall scores in ambulatory continuity practice than did traditional residents in 1985-86. Primary care attendings gave lower scores to primary care residents than did other faculty.

Ambulatory Care↗

Emergency department detection and follow-up of high blood pressure: use and effectiveness of community health workers.

This study introduced trained paraprofessionals, community health workers (CHWs), into the emergency department (ED) to supplement providers' routine efforts in high blood pressure (HBP) detection, treatment, and follow-up among high-risk black men. In a demonstration project over a 2-year period, CHWs provided (1) BP and pulse measurements, and educational counseling regarding HBP and cardiovascular risk factors; (2) telephone preappointment reminders to improve ED follow-up visit rates; and (3) recontact of patients failing to show for their ED follow-up visits to improve return rates even after missed BP appointments. Results of preappointment reminders by CHWs showed a 19% improvement in appointment keeping (P less than .001). With a sample of patients who had failed to return for a follow-up visit, CHW contact was also effective, showing an overall improvement rate of 7% (P less than .001). The results reported support the idea that individuals from the community, trained as paraprofessionals, can improve appointment keeping as well as be useful in assisting in screening and counseling for chronic conditions within the ED. These CHWs are seen as having the additional advantage of enhancing the integration of the ED, the community, and continuing care sites. The approaches used in this study should be applicable and may serve as a model for the approach to other chronic conditions experienced in urban high-risk communities.

Adult↗

Measuring medical residents' chart-documentation practices.

To determine the adequacy of medical history documentation, investigators videotaped 26 clinical interviews performed by medical residents in ambulatory practice, and the contents of each videotape were compared with the corresponding entries in the medical record. The residents recorded a little over half of all medical history information observed on the videotapes. Medical issues were more often documented than psychosocial or health behaviors. The residents in their second postgraduate year had the best documentation practices regardless of their residency track (primary-care or traditional track). Also, no difference was noted between the performances of primary-care internal medicine residents and traditional internal medicine residents. For one-quarter of the patients, less than 40 percent of the information that was present on the videotapes was documented in their charts. The residents documented more-severe illnesses better than less-severe ones and documented the medical histories of older patients better than the histories of younger ones. The residents' records of health behavior and psychosocial concerns were less complete for women patients. To improve chart documentation, members of both the attending and the house staffs should review videotapes and corresponding medical records of clinical encounters to help them investigate factors causing inadequate chart-documentation.

Adult↗

Healthcare needs of HIV-infected persons in hospital, outpatient, home, and long-term care settings.

In this descriptive study, healthcare needs reported by 386 HIV-infected persons from all risk categories and their primary nurses from four care settings (hospital, outpatient, long-term care, and home) are identified. Healthcare needs were classified into four domains of nursing practice using a conceptual framework from community health nursing--physiologic, psychosocial, health behaviors, environmental--and were assessed using the Healthcare Needs Scale for Patients with HIV/AIDS. Nurses' perceptions of major healthcare needs across all settings centered around decreased physical endurance, limited physical mobility, and sensory deficits. Patients' needs focused on financial issues. The results reflect the multidimensional nature of this infection and provide direction for clinical practice.

Activities of Daily Living↗

The American College of Nurse-Midwives' Domestic Violence Education Project: evaluation and results.

From October 1994 through September 1998, the American College of Nurse Midwives conducted a nationwide Domestic Violence Education Project. The project aimed to encourage universal screening for domestic violence among all women being seen for care. A four-pronged set of objectives was used, including policy, basic education, continuing education, and advocacy/activism. A description of the project and the results of the project evaluation, including replicable features, are presented. Process and outcome evaluations were performed using both quantitative and qualitative data. Surveys, interviews, and site visits formed the basis for the evaluation of the policy reform, education program, and advocacy components. Pretests and posttests of training participants formed the basis of the evaluation of the continuing education component. All project objectives were met. Policy reform occurred as expected. Changes were noted in education programs in both didactic content and clinical exposure. Changes in clinical behavior as assessed by the pretests and posttests look promising, although numbers of respondents at 12 and 24 months after training are small. Participants reported an increase in advocacy and activism. The Domestic Violence Education Project seems to be a successful and somewhat replicable model for changing attitudes about a health topic (among providers) with possible implications for clinical practice.

Curriculum↗

Substance misuse and HIV/AIDS risks among delinquents: a prevention challenge.

In the United States, there is growing concern that adolescents are at increasing risk for HIV-1 infection due to recreational substance use and sexual activity. Self-report questionnaires from a sample of 224 incarcerated delinquents quantified associations between drug use, sex, and other behaviors which risk HIV-1 infection. High rates of substance use and HIV-risking behaviors were found. Significant correlations between levels of substance use and both behavioral and attitudinal barriers to HIV/AIDS prevention programming were observed. This evidence and other subgroup differences in denial of vulnerability and in practice of preventive behaviors indicate the need for different approaches to prevention. An integrated HIV/AIDS and substance misuse prevention program is discussed as a viable alternative to the usual knowledge-enhancing programs.

Acquired Immunodeficiency Syndrome↗