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Significant Disturbance (significant + disturbance)

Distribution by Scientific Domains

Medical Sciences	75%

Selected Abstracts

Metastable zone determination of lipid systems: Ultrasound velocity versus optical back-reflectance measurements

EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 5 2010
Kesarin Chaleepa
Abstract The metastable zone width (MZW) of a multi-component system as influenced by the process parameters cooling rate, agitation speed, and additive concentration was determined via ultrasound velocity measurements. The results were compared with those obtained by optical back-reflectance measurements (ORM) using coconut oil as a model substance. Increasing the cooling rate led to the shift of the nucleation point to lower temperatures. This tendency was better visualized by the ultrasonic curves while a significant disturbance of the ORM signal could be observed. Agitation led to an increase of the nucleation temperature and hence a narrower metastable zone. The influence of an additive on the MZW was found to strongly depend on its concentration. The MZW detected by the ultrasound technique was narrower compared to that obtained by the ORM method, indicating the faster response to the phase transition of the ultrasound technique. Another advantage of the ultrasound technique was the in situ evaluation of the experimental data, while ORM needed a linear fitting to estimate the saturation temperature. Furthermore, ultrasound velocity measurements are based on density determination of the medium whereas the ORM sensor is able to detect only particles that are located within the measuring zone and possess a well-defined size. Practical applications: MZW is one of the most important parameters that determine the characteristics of crystalline products. However, a proper technique that can be used in MZW detection in fat systems has rarely been reported, due to the difficulties in dealing with natural fats. The findings of this study can greatly help those who are involved in the field of fat crystallization from both the academic and the practical point of view. This is due to the fact that new and promising techniques for the online and in situ determination of the MZW of fats, with high accuracy, and reproducibility, under most process conditions, were clarified in this work. The readers can easily follow the procedure developed in this paper. Also information about the influence of process parameters and additives on the MZW is included. [source]

Childhood Onset Vulvar Lichen Sclerosus Does Not Resolve at Puberty: A Prospective Case Series

PEDIATRIC DERMATOLOGY, Issue 6 2009
Saxon D. Smith M.B.Ch.B.
However when it occurs in adult women it is accepted that remission is unlikely and that in addition untreated or inadequately treated disease may be complicated by significant disturbance of vulvar architecture and less commonly squamous cell carcinoma. Our database reveals 18 girls who developed lichen sclerosus prior to puberty who are now adolescents or young adults. Twelve have remained under surveillance and the other six patients have been lost to follow-up. We report a prospective series of these 12 patients. Three patients have achieved complete remission sustained for three or more years, all prior to menarche. Nine patients, or 75% of the cohort, who still had active lichen sclerosus at puberty continue to require maintenance therapy after menarche. Of the 12, six have had significant disturbance of vulvar architecture. The concept that prepubertal lichen sclerosus resolves at puberty would appear not to be true in the majority of patients. Even when diagnosed early and treated effectively, childhood onset lichen sclerosus may be complicated by distortion of vulvar architecture. [source]

Paraoxonase 1 activities and polymorphisms in autism spectrum disorders

JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 3 2010
Sergiu P. Pa
Abstract Autism spectrum disorders (ASD) comprise a complex and heterogeneous group of conditions of unknown aetiology, characterized by significant disturbances in social, communicative and behavioural functioning. Recent studies suggested a possible implication of the high-density lipoprotein associated esterase/lactonase paraoxonase 1 (PON1) in ASD. In the present study, we aimed at investigating the PON1 status in a group of 50 children with ASD as compared to healthy age and sex matched control participants. We evaluated PON1 bioavailability (i.e. arylesterase activity) and catalytic activity (i.e. paraoxonase activity) in plasma using spectrophotometric methods and the two common polymorphisms in the PON1 coding region (Q192R, L55M) by employing Light Cycler real-time PCR. We found that both PON1 arylesterase and PON1 paraoxonase activities were decreased in autistic patients (respectively, P < 0.001, P < 0.05), but no association with less active variants of the PON1 gene was found. The PON1 phenotype, inferred from the two-dimensional enzyme analysis, had a similar distribution in the ASD group and the control group. In conclusion, both the bioavailability and the catalytic activity of PON1 are impaired in ASD, despite no association with the Q192R and L55M polymorphisms in the PON1 gene and a normal distribution of the PON1 phenotype. [source]

Polysomnography in patients with post-traumatic stress disorder

PSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 3 2010
Sinan Yetkin MD
Aims:, The purpose of the present study was to investigate sleep structure in post-traumatic stress disorder (PTSD) patients with and without any psychiatric comorbidities. The relationship between sleep variables and measurements of clinical symptom severity were also investigated. Methods:, Sleep patterns of 24 non-medicated male PTSD patients and 16 age- and sex-matched normal controls were investigated on polysomnography on two consecutive nights. Six PTSD-only patients and 15 PTSD patients with major depressive disorder (MDD) were also compared to normal controls. Sleep variables were correlated with PTSD symptoms. Results:, Compared to the normal controls, the PTSD patients with MDD had difficulty initiating sleep, poor sleep efficiency, decreased total sleep time, decreased slow wave sleep (SWS), and a reduced rapid eye movement (REM) sleep latency. The PTSD patients without any comorbid psychiatric disorders had moderately significant disturbances of sleep continuity, and decreased SWS, but no abnormalities of REM sleep. REM sleep latency was inversely proportional to the severity of startle response. SWS was found to be inversely correlated with the severity of psychogenic amnesia. Conclusions:, PTSD patients have disturbance of sleep continuity, and SWS deficit, without the impact of comorbid depression on sleep. The relationship between SWS and the inability to recall an important aspect of trauma may indicate the role of sleep in the consolidation of traumatic memories. The relationship between the severity of the startle response and REM latency may suggest that REM sleep physiology shares common substrates with the symptoms of PTSD. [source]