197 research outputs found
Symmetry and Multiplicity of Solutions in a Two-Dimensional Landau–de Gennes Model for Liquid Crystals
We consider a variational two-dimensional Landau–de Gennes model in the
theory of nematic liquid crystals in a disk of radius R. We prove that under a
symmetric boundary condition carrying a topological defect of degree k
2 for some given even non-zero integer k, there are exactly two minimizers for all large enough
R. We show that the minimizers do not inherit the full symmetry structure of the
energy functional and the boundary data. We further show that there are at least
five symmetric critical points
Laparoscopic herniorrhaphy in children.
The authors report their experience in laparoscopic repair of inguinal hernias in children. From May 2010 to November 2013, 122 patients with inguinal hernia underwent laparoscopic herniorrhaphy (92 males and 30 females). Telescope used was 5 mm, while trocars for the operative instruments were 3 or 2 mm. After introducing the camera at the umbilical level and trocars in triangulation, a 4-0 nonabsorbable monofilament suture was inserted directly through the abdominal wall. The internal inguinal ring was then closed by N or double N suture. All operations were performed in one-day surgery setting. In the case of association of inguinal and umbilical hernia an original technique was performed for positioning and fixing the umbilical trocar and for the primary closure of the abdominal wall defect. The postoperative follow-up consisted of outpatient visits at 1 week and 1, 3, and 6 months. The mean age of patients was 38.5 months. Of all patients, 26 were also suffering from umbilical hernia (19 males and 7 females). A total of 160 herniorrhaphies were performed; 84 were unilateral (66 inguinal hernia, 18 inguinal hernia associated with umbilical hernia), 38 bilateral (30 inguinal hernia, 8 inguinal hernia associated with umbilical hernia). Nine of 122 patients (6 males and 3 females) were operated in emergency for incarcerated hernia. A pre-operative diagnosis of unilateral inguinal hernia was performed in 106 cases. Of these patients, laparoscopy revealed a controlateral open internal inguinal ring in 22 cases (20.7%). The mean operative time was 29.9±15.9 min for the monolateral herniorrhaphies, while in case of bilateral repair the mean operative time was 41.5±10.4 min. The mean operative time for the repair of unilateral inguinal hernia associated with umbilical hernia was 30.1±7.4 while for the correction of bilateral inguinal hernia associated with umbilical hernia 39.5±10.6 min. There were 3 recurrences (1.8%): 2 cases in unilateral repair and 1 case a unilateral recurrence in a bilateral repair. No other complications were seen. Laparoscopic repair of inguinal hernia in children performed in this experience resulted a safe and effective procedure
Functional and Topological Properties in Hepatocellular Carcinoma Transcriptome
Hepatocellular carcinoma (HCC) is a leading cause of global cancer mortality. However, little is known about the precise molecular mechanisms involved in tumor formation and pathogenesis. The primary goal of this study was to elucidate genome-wide molecular networks involved in development of HCC with multiple etiologies by exploring high quality microarray data. We undertook a comparative network analysis across 264 human microarray profiles monitoring transcript changes in healthy liver, liver cirrhosis, and HCC with viral and alcoholic etiologies. Gene co-expression profiling was used to derive a consensus gene relevance network of HCC progression that consisted of 798 genes and 2,012 links. The HCC interactome was further confirmed to be phenotype-specific and non-random. Additionally, we confirmed that co-expressed genes are more likely to share biological function, but not sub-cellular localization. Analysis of individual HCC genes revealed that they are topologically central in a human protein-protein interaction network. We used quantitative RT-PCR in a cohort of normal liver tissue (n = 8), hepatitis C virus (HCV)-induced chronic liver disease (n = 9), and HCC (n = 7) to validate co-expressions of several well-connected genes, namely ASPM, CDKN3, NEK2, RACGAP1, and TOP2A. We show that HCC is a heterogeneous disorder, underpinned by complex cross talk between immune response, cell cycle, and mRNA translation pathways. Our work provides a systems-wide resource for deeper understanding of molecular mechanisms in HCC progression and may be used further to define novel targets for efficient treatment or diagnosis of this disease
IDENTIFICATION OF LAND DEGRADATION AREAS BY QUERYING THE GEOREFERENCED NATIONAL DATABASES IN ORDER TO DELINEATE THE POTENTIAL LAND RECLAMATION PERIMETERS AT LOCAL LEVEL
The aim of this paper is to identify land degradation areas at administrative local level using GIS-based methods and geo-referenced databases including soil, geology, terrain, land use, and land cover data. The Local Administrative Unit of Scorțoasa, Buzău County, was selected as study case, covering an area of about 9595 ha of hill landscape. With data which included soil maps, land use maps and geology maps at medium scales (1:200 000) land degradation map was obtained for cropland and grazing land based on some attributes such as: water erosion, wind erosion, landslides, salinization, water logging. The combined land degradation map, joining the different data, presents a medium resolution, given the different initial scales of the used maps. The approach adopted in this paper consisting in combining different data sets, requires field validation, but can provide primary reliable information for delineation of potential land reclamation areas
GIANT OPTICAL NONLINEARITY OF HETEROSTRUCTURES WITH InP SELF-ASSEMBLED QUANTUM DOTS
A nonlinear reection of the heterostructures with InP self-assembled quantumdots is studied by pump-probe technique. A saturation of pump-probe signal inthe spectral region of the absorption of quantum dots is found at extremely lowpump power density of about 1 W/cm2. This value together with estimation ofthe absorption coefficient leads to the conclusion that saturation of the nonlinearreection occurs when quantum dot absorbs only single quantum of the light. Thisis a real evidence of the giant optical nonlinearity of the quantum dots.24th International Conference on the Physics of Semiconductors : Jerusalem, Israel August 2-7, 199
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