38 research outputs found
Size scaling of the addition spectra in silicon quantum dots
We investigate small artificial quantum dots obtained by geometrically
controlled resistive confinement in low mobility silicon-on-insulator
nanowires. Addition spectra were recorded at low temperature for various dot
areas fixed by lithography. We compare the standard deviation of the addition
spectra with theory in the high electron concentration regime. We find that the
standard deviation scales as the inverse area of the dot and its absolute value
is comparable to the energy spacing of the one particle spectrum.Comment: 4 pages, 5 figure
Coulomb Blockade in low mobility nanometer size Si:MOSFETs
We investigate coherent transport in Si:MOSFETs with nominal gate lengths 50
to 100nm and various widths at very low temperature. Independent of the
geometry, localized states appear when G=e^{2}/h and transport is dominated by
resonant tunnelling through a single quantum dot formed by an impurity
potential. We find that the typical size of the relevant impurity quantum dot
is comparable to the channel length and that the periodicity of the observed
Coulomb blockade oscillations is roughly inversely proportional to the channel
length. The spectrum of resonances and the nonlinear I-V curves allow to
measure the charging energy and the mean level energy spacing for electrons in
the localized state. Furthermore, we find that in the dielectric regime, the
variance var(lng) of the logarithmic conductance lng is proportional to its
average value consistent with one-electron scaling models.Comment: 4 pages, 4 figure
Fatores de risco para quedas em pacientes adultos hospitalizados: um estudo caso-controle
Objective: to identify risk factors for falls in hospitalized adult patients. Methods: a matched case-control study (one control for each case). A quantitative study conducted in clinical and surgical units of a teaching hospital in Southern Brazil. The sample comprised 358 patients. Data were collected over 18 months between 2013-2014. Data analysis was performed with descriptive statistics and conditional logistic regression using Microsoft Excel and SPSS version 18.0. Results: risk factors identified were: disorientation/confusion [OR 4.25 (1.99 to 9.08), p<0.001]; frequent urination [OR 4.50 (1.86 to 10.87), p=0.001]; walking limitation [OR 4.34 (2.05 to 9.14), p<0.001]; absence of caregiver [OR 0.37 (0.22 to 0.63), p<0.001]; postoperative period [OR 0.50 (0.26 to 0.94), p=0.03]; and number of medications administered within 72 hours prior the fall [OR 1.20 (1.04 to 1.39) p=0.01]. Conclusion: risk for falls is multifactorial. However, understanding these factors provides support to clinical decision-making and positively influences patient safety.Objetivo: identificar los factores de riesgo para la ocurrencia de caídas en pacientes adultos hospitalizados. Métodos: un estudio caso-control emparejado (un control para cada caso). Investigación cuantitativa llevada a cabo en unidades clínicas y quirúrgicas de un hospital universitario en el Sur de Brasil. La muestra constó de 358 pacientes. Se recopilaron datos durante 18 meses, entre 2013-2014. El análisis de los datos se realizó mediante estadística descriptiva y regresión logística condicional, utilizando el Microsoft Excel y el SPSS versión 18.0. Resultados: los factores de riesgo identificados fueron: desorientación/confusión [OR 4,25 (1,99 a 9,08), p<0,001]; micción frecuente [OR 4,50 (1,86 a 10,87), p=0,001]; limitación para caminar [OR 4,34 (2,05 a 9,14), p<0,001]; ausencia de cuidadores [OR 0,37 (0,22 a 0,63), p<0,001]; período postoperatorio [OR 0,50 (0,26 a 0,94), p=0,03]; y número de medicamentos administrados dentro de las 72 horas previas a la caída [OR 1,20 (1,04 a 1,39) p=0,01]. Conclusión: los riesgos de caídas son multifactoriales. Sin embargo, la comprensión de estos factores respalda la toma de decisiones clínicas y tiene un impacto positivo en la seguridad del paciente.Objetivo: identificar os fatores de risco para a ocorrência de quedas em pacientes adultos hospitalizados. Métodos: estudo do tipo caso-controle pareado (um controle para cada caso). Pesquisa quantitativa realizada em unidades clínicas e cirúrgicas de um hospital universitário da região Sul do Brasil. A amostra incluiu 358 pacientes. Os dados foram coletados durante 18 meses, entre 2013-2014. A análise dos dados foi realizada por meio de estatística descritiva e regressão logística condicional, utilizando o Microsoft Excel e o SPSS versão 18.0. Resultados: os fatores de risco identificados foram: desorientação/confusão [OR 4,25 (1,99 a 9,08), p<0,001]; micção frequente [OR 4,50 (1,86 a 10,87), p=0,001]; limitação para caminhar [OR 4,34 (2,05 a 9,14), p<0,001]; ausência de cuidador [OR 0,37 (0,22 a 0,63), p<0,001]; período pós-operatório [OR 0,50 (0,26 a 0,94), p=0,03]; e o número de medicamentos administrados nas 72 horas anteriores à queda [OR 1,20 (1,04 a 1,39) p=0,01]. Conclusão: os riscos para quedas são multifatoriais. Todavia, conhecê-los dá suporte à decisão clínica do enfermeiro, o que contribui para a busca das melhores intervenções preventivas e impacta positivamente na segurança dos pacientes
Blood pressure self-monitoring in pregnancy: examining feasibility in a prospective cohort study
Background: Raised blood pressure (BP) affects approximately 10% of pregnancies worldwide, and a high proportion of affected women develop pre-eclampsia. This study aimed to evaluate the feasibility of self-monitoring of BP in pregnancy in women at higher risk of pre-eclampsia.
Methods: This prospective cohort study of self-monitoring BP in pregnancy was carried out in two hospital trusts in Birmingham and Oxford and thirteen primary care practices in Oxfordshire. Eligible women were those defined by the UK National Institute for Health and Care Excellence (NICE) guidelines as at higher risk of pre-eclampsia. A total of 201 participants were recruited between 12 and 16 weeks of pregnancy and were asked to take two BP readings twice daily three times a week through their pregnancy. Primary outcomes were recruitment, retention and persistence of self-monitoring. Study recruitment and retention were analysed with descriptive statistics. Survival analysis was used to evaluate the persistence of self-monitoring and the performance of self-monitoring in the early detection of gestational hypertension, compared to clinic BP monitoring. Secondary outcomes were the mean clinic and self-monitored BP readings and the performance of self-monitoring in the detection of gestational hypertension and pre-eclampsia
compared to clinic BP.
Results: Of 201 women recruited, 161 (80%) remained in the study at 36 weeks or to the end of their pregnancy, 162 (81%) provided any home readings suitable for analysis, 148 (74%) continued to self-monitor at 20 weeks and 107 (66%) at 36 weeks. Self-monitored readings were similar in value to contemporaneous matched clinic readings for both systolic and diastolic BP. Of the 23 who developed gestational hypertension or pre-eclampsia and self-monitored, 9(39%) had a raised home BP prior to a raised clinic BP.
Conclusions: Self-monitoring of BP in pregnancy is feasible and has potential to be useful in the early detection of gestational hypertensive disorders but maintaining self-monitoring throughout pregnancy requires support and probably enhanced training
Cancer-associated fibroblasts promote bone invasion in oral squamous cell carcinoma
Background: The molecular mechanisms involved in the invasion of bone by oral squamous cell carcinomas (OSCC) are poorly understood, and little is known about the role of cancer-associated fibroblasts (CAF), the presence of which confers a poor prognosis.
Methods: Clinicopathological data from 277 OSCC cases involving bone resections were reviewed, and 32 cases thoroughly analysed histologically. Immunohistochemistry was used to examine αSMA, RANKL and OPG. Western blotting and qPCR were used to assess myofibroblast (CAF-like) differentiation, RANKL and OPG expression in vitro, and RANKL secretion was analysed by ELISA. Osteoclastogenesis was examined using TRAP staining, multinucleation and pit forming assays.
Results: Fibrous stroma intervened between tumour and bone in the majority of cases, with no direct contact between cancer cells and bone. RANKL and OPG, two proteins key to regulating bone resorption, were expressed in tumour cells as well as fibrous stroma adjacent to bone and αSMA-positive myofibroblastic CAF were consistently seen infiltrating into bone ahead of tumour cells. Human primary osteoblasts cultured with conditioned media from human OSCC-derived cells and human primary CAF showed a significant increase in RANKL and a decline in OPG mRNA expression. RANKL secretion was significantly increased in primary oral fibroblasts induced to differentiate into a CAF-like phenotype by transforming growth factor-β1 (TGF-β1) treatment and in primary CAF. Indirect co-culture of murine macrophages with conditioned media from CAF (experimentally derived and isolated from OSCCs) resulted in a marked increase in osteoclastogenesis (in excess of that provoked by cancer cells) determined by tartrate-resistant acid phosphatase activity, multinucleation and resorption pit formation.
Conclusions: This study is the first to describe a functional role for CAFs in bone invasion and turnover, identifying a novel potential therapeutic target and diagnostic indicator in this difficult to treat bone invasive malignancy
Limited consumption of 100% fruit juices and sugar sweetened beverages in Japanese toddler and preschool children
Japanese toddler and preschool children, ages 1.5–5 years, have lower rates of obesity, ≥95 th percentile body mass index, compared with North American ones. We examined parental reported beverage consumption patterns in 3 Japanese based mother-child cohorts from three different regions of Japan compared with data from cross-sectional and longitudinal studies from North America. Specifically, we used data from the Hamamatsu Birth Cohort for Mothers and Children (HBC Study) in Hamamatsu (Shizuoka Prefecture), the Seiiku Boshi Birth Cohort from Setagaya, Tokyo and the TMM BirThree Cohort Study from Miyagi. We additionally compared cross-sectional data from preschoolers from 24 prefectures in Japan as previously reported from a national study. While Japanese children had lower but comparable rates to North American children for introduction of sugar-sweetened beverages and 100% fruit juices, Japanese children consumed these beverages daily at a much lower level than North American children. Additionally, North American children may get more added sugars from soda and fruit juices as a relative percentage of total added sugar. By contrast, Japanese children consume more sweetened dairy drinks as a relative percentage of total added sugar. Sweetened dairy drinks may have the added benefits of including fats, calcium and probiotics which may be associated with lower risk for obesity compared with consumption of other types of sugar sweetened beverages
Real-Time Monitoring of Lipid Exchange via Fusion of Peptide Based Lipid-Nanodiscs
Real-Time
Monitoring of Lipid Exchange via Fusion
of Peptide Based Lipid-Nanodisc
Real-Time Monitoring of Lipid Exchange via Fusion of Peptide Based Lipid-Nanodiscs
Real-Time
Monitoring of Lipid Exchange via Fusion
of Peptide Based Lipid-Nanodisc