Nonlinear Measures for Characterizing Rough Surface Morphologies

We develop a new approach to characterizing the morphology of rough surfaces based on the analysis of the scaling properties of contour loops, i.e. loops of constant height. Given a height profile of the surface we perform independent measurements of the fractal dimension of contour loops, and the exponent that characterizes their size distribution. Scaling formulas are derived and used to relate these two geometrical exponents to the roughness exponent of a self-affine surface, thus providing independent measurements of this important quantity. Furthermore, we define the scale dependent curvature and demonstrate that by measuring its third moment departures of the height fluctuations from Gaussian behavior can be ascertained. These nonlinear measures are used to characterize the morphology of computer generated Gaussian rough surfaces, surfaces obtained in numerical simulations of a simple growth model, and surfaces observed by scanning-tunneling-microscopes. For experimentally realized surfaces the self-affine scaling is cut off by a correlation length, and we generalize our theory of contour loops to take this into account.Comment: 39 pages and 18 figures included; comments to [email protected]

Hepatocellular Carcinoma: An Unusual Presentation of this Rare Clinical Entity in Children

Malignant hepatic tumors are rare in children and hepatocellular carcinomas only represent 20% of cases. A previously healthy 10 year-old male was admitted for sudden abdominal pain. Ultrasound imaging showed an ileo-ileal intussusception with spontaneous resolution, but in the face of worsening pain, fever, and a palpable epigastric mass, abdominal magnetic resonance imaging was performed, showing a liver lesion. Laboratory tests presented elevated liver enzymes and C-reactive protein, so a liver abscess was considered and treated with metronidazole plus ceftriaxone. All of the microbiology tests as well as tumoral markers were negative. Despite clinical and laboratory improvement, the lesion persisted in the imaging. A liver biopsy confirmed a hepatocellular carcinoma, and the patient was submitted to surgical resection and chemotherapy. Contrarily to adults in whom most cases are secondary to chronic liver disease, children may not have risk factors for the disease, which makes it harder to make a prompt diagnosis.info:eu-repo/semantics/publishedVersio

Perivascular Epithelioid Cell Tumor: A Case Report of a Rare Entity

Perivascular epithelioid cell tumor is a rare mesenchymal tumor with myomelanocytic differentiation. It mainly occurs in middle-aged females and can be found at any location. The differential diagnosis is broad but the immunohistochemical biomarkers establish the diagnosis. A 4-year-old girl was referred to a pediatric gastroenterology clinic due to recurrent umbilical pain and the workup revealed biliary lithiasis. She remained in follow-up, asymptomatic, no physical findings, and stable ultrasound. Six years later, a supra-umbilical mass was detected by ultrasound, and the magnetic resonance imaging revealed a highly vascularized intraperitoneal tumor with well-defined limits. Surgical mass resection was performed, and the histology revealed morphological and immunohistochemical aspects of a perivascular epithelioid cell tumor of the abdominal wall. Given the size of the lesion (> 5 cm) and admitting uncertain malignant potential, she was submitted to margin enlargement. Four years later, she remains asymptomatic without clinical or imagiological evidence of relapse.info:eu-repo/semantics/publishedVersio

Identification and validation of clinical predictors for the risk of neurological involvement in children with hand, foot, and mouth disease in Sarawak

Background: Human enterovirus 71 (HEV71) can cause Hand, foot, and mouth disease (HFMD) with neurological complications, which may rapidly progress to fulminant cardiorespiratory failure, and death. Early recognition of children at risk is the key to reduce acute mortality and morbidity. Methods: We examined data collected through a prospective clinical study of HFMD conducted between 2000 and 2006 that included 3 distinct outbreaks of HEV71 to identify risk factors associated with neurological involvement in children with HFMD. Results: Total duration of fever ≥ 3 days, peak temperature ≥ 38.5°C and history of lethargy were identified as independent risk factors for neurological involvement (evident by CSF pleocytosis) in the analysis of 725 children admitted during the first phase of the study. When they were validated in the second phase of the study, two or more (≥ 2) risk factors were present in 162 (65%) of 250 children with CSF pleocytosis compared with 56 (30%) of 186 children with no CSF pleocytosis (OR 4.27, 95% CI2.79–6.56, p < 0.0001). The usefulness of the three risk factors in identifying children with CSF pleocytosis on hospital admission during the second phase of the study was also tested. Peak temperature ≥ 38.5°C and history of lethargy had the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 28%(48/174), 89%(125/140), 76%(48/63) and 50%(125/251), respectively in predicting CSF pleocytosis in children that were seen within the first 2 days of febrile illness. For those presented on the 3rd or later day of febrile illness, the sensitivity, specificity, PPV and NPV of ≥ 2 risk factors predictive of CSF pleocytosis were 75%(57/ 76), 59%(27/46), 75%(57/76) and 59%(27/46), respectively. Conclusion: Three readily elicited clinical risk factors were identified to help detect children at risk of neurological involvement. These risk factors may serve as a guide to clinicians to decide the need for hospitalization and further investigation, including cerebrospinal fluid examination, and close monitoring for disease progression in children with HFMD

Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe

Enterovirus 75 Encephalitis in Children, Southern India

Recent outbreaks of enterovirus in Southeast Asia emphasize difficulties in diagnosis of this infection. To address this issue, we report 5 (4.7%) children infected with enterovirus 75 among 106 children with acute encephalitis syndrome during 2005–2007 in southern India. Throat swab specimens may be useful for diagnosis of enterovirus 75 infection

Dengue: a continuing global threat.

Dengue fever and dengue haemorrhagic fever are important arthropod-borne viral diseases. Each year, there are ∼50 million dengue infections and ∼500,000 individuals are hospitalized with dengue haemorrhagic fever, mainly in Southeast Asia, the Pacific and the Americas. Illness is produced by any of the four dengue virus serotypes. A global strategy aimed at increasing the capacity for surveillance and outbreak response, changing behaviours and reducing the disease burden using integrated vector management in conjunction with early and accurate diagnosis has been advocated. Antiviral drugs and vaccines that are currently under development could also make an important contribution to dengue control in the future

The association between subjective caregiver burden and depressive symptoms in carers of older relatives: a systematic review and meta-analysis

BackgroundFamily carers are an important source of care for older people. Although several studies have reported that subjective caregiver burden is related to depressive symptoms there are no systematic reviews quantifying this association.ObjectiveTo establish the extent to which subjective caregiver burden is associated with depressive symptoms and whether this association would vary by study or care characteristics.MethodsWe searched major databases such as PubMed, CINAHL, PsycINFO, Scopus and ISI Proceedings up to March 2018, and conducted a meta-analysis of included studies. Summary estimates of the association were obtained using a random-effects model to improve generalisation of findings.ResultsAfter screening of 4,688 articles, 55 studies were included providing a total of 56 independent comparisons with a total of 9,847 carers from data across 20 countries. There was a large, positive association between subjective caregiver burden and depressive symptoms ([Formula: see text] = 0.514; 95% CI = 0.486, 0.541), with very low heterogeneity amongst individual studies (I2 = 8.6%). Sensitivity analyses showed no differences between cross-sectional or repeated measures ([Formula: see text] = 0.521; 95% CI = 0.491, 0.550; 51 samples) and longitudinal studies ([Formula: see text] = 0.454; 95% CI = 0.398, 0.508; 6 samples). We found a higher effect size for those caring for people living with dementia compared to those caring for frail older people, and stroke survivors. Carer sex, age and kinship did not change the estimate of the effect.ConclusionsSubjective caregiver burden is a significant risk factor for depressive symptoms in carers of older people and may precipitate clinical depression. Those caring for people with dementia experience greater burden. There is a need for longitudinal evaluations examining the effects of potential mediators of the association of subjective burden and depressive symptoms. Future interventions should test whether minimizing subjective burden may modify the risk of developing depression in carers of older relatives

Sentinel surveillance for human enterovirus 71 in Sarawak, Malaysia: lessons from the first 7 years

BACKGROUND: A major outbreak of human enterovirus 71-associated hand, foot and mouth disease in Sarawak in 1997 marked the beginning of a series of outbreaks in the Asia Pacific region. Some of these outbreaks had unusually high numbers of fatalities and this generated much fear and anxiety in the region. METHODS: We established a sentinel surveillance programme for hand, foot and mouth disease in Sarawak, Malaysia, in March 1998, and the observations of the first 7 years are described here. Virus isolation, serotyping and genotyping were performed on throat, rectal, vesicle and other swabs. RESULTS: During this period Sarawak had two outbreaks of human enterovirus 71, in 2000 and 2003. The predominant strains circulating in the outbreaks of 1997, 2000 and 2003 were all from genogroup B, but the strains isolated during each outbreak were genetically distinct from each other. Human enterovirus 71 outbreaks occurred in a cyclical pattern every three years and Coxsackievirus A16 co-circulated with human enterovirus 71. Although vesicles were most likely to yield an isolate, this sample was not generally available from most cases and obtaining throat swabs was thus found to be the most efficient way to obtain virological information. CONCLUSION: Knowledge of the epidemiology of human enterovirus 71 transmission will allow public health personnel to predict when outbreaks might occur and to plan interventions in an effective manner in order to reduce the burden of disease

Evaluation of two commercially available ELISAs for the diagnosis of Japanese encephalitis applied to field samples

To compare two commercially available kits, Japanese Encephalitis-Dengue IgM Combo ELISA (Panbio Diagnostics) and JEV-CheX IgM capture ELISA (XCyton Diagnostics Limited), to a reference standard (Universiti Malaysia Sarawak – Venture Technologies VT ELISA). Methods Samples were obtained from 172 ⁄ 192 children presenting to a site in rural India with acute encephalitis syndrome