13 research outputs found
Changes in neuropsychological functioning following temporal lobectomy in patients with temporal lobe epilepsy
Purpose: This study was conducted to evaluate the changes in neuropsychological functioning in patients with temporal lobe epilepsy (TLE) after temporal lobe resection. Methods: Fifty-four TLE patients were evaluated before and after surgery using comprehensive neuropsychological tests to assess general intelligence, executive functioning, language, verbal and visual memory, working memory, visuo-spatial ability, attention and motor function. Results: The patients with left TLE showed no impairment of neuropsychological functioning after surgery, with the exception of auditory immediate memory. Furthermore, they showed significant improvement in performance IQ, executive function, working memory, visual memory, attention and psychomotor speed. The patients with right TLE did not show any significant impairment in post-operative neuropsychological functioning. They showed improvements in intellectual and executive functions, language, visual memory, visuo-spatial ability, attention and motor function post-operatively. The patients with hippocampal sclerosis showed greater post-operative improvements than the patients without hippocampal sclerosis regardless of the side. Patients with better pre-operative neuropsychological function had a higher chance of successfully discontinuing all seizure medications after surgery. Discussion: The results of this study suggest that temporal lobectomy does not harm the neuropsychological functioning of patients with intractable TLE and that it improves cognitive functions of the contralateral hemisphere. © 2009 W. S. Maney & Son Ltd
Deformation rate controls atomic-scale dynamic strain aging and phase transformation in high Mn TRIP steels
Dynamic strain aging (DSA) in engineering metallic alloys triggers a degradation of the relevant properties of these material. Atomic-scale understanding of DSA is essential for achieving strong and ductile high-Mn martensitic-austenitic transformation induced plasticity (TRIP) steels. Using multiple-scale analytical techniques, we report the influence of carbon addition and strain rates on the mechanical properties and associated deformation-induced phase transformation of these steels. Specific attention is also placed on the origin of DSA at the atomic scale. We find that controlling these parameters (carbon and strain rate) can be used to manipulate the room temperature reverse transformation from martensite to austenite, plastic instability, short-range ordering (SRO), TRIP effect, and strain hardening of these steels. Thus, our results demonstrate that the SRO caused by short-range clustering (SRC) is linked to the DSA, and that high-strain-rate deformation induces an increase in the carbon concentration of SRC, leading to the DSA suppression. Hence, we suggest that manipulating phase transformation and DSA is utilized to achieve strong and ductile steels with continuous and stable flow. ? 2017 Acta Materialia Inc.119sciescopu
A stereo PIV measurement of a model ship wake in a towing tank with uncertainty assessment
Detailed information of the flow around a ship is essential for designing the hull because it is related to the propeller performance, maneuverability, and vibration. Thus, lots of experimental and computational researches have been executed to measure or analyze the stern flow of vessels. In this paper, the newly installed underwater SPIV system in Seoul National University Towing Tank is introduced with its measurement results and estimated uncertainty. The SPIV system was installed on the towing carriage which runs along side rails of the towing tank. With the underwater SPIV system, the uniform flow, made by running the towing carriage without a model, was firstly measured to investigate the uncertainty assessment. Uniform flow measurement results for each direction of the coordinate system were analyzed to estimate the random error and systematic error, following the ASME test uncertainty. The reference speed for the longitudinal and transverse uniform flow measurement was set to 1.0m/s and 1.5m/s, which is general towing speed range of model ships in the towing tank. In the uniform flow measurement results, the systematic error, the difference of ensemble-averaged speed and reference speed from the encoder of the towing carriage, was below 1.5% of the towing speed and the random error, derived from the standard deviation of the ensemble-averaged speed, was 4% of the reference speed. After the uncertainty assessment, the nominal wake, the flow on the propeller location with absence of the propeller, was measured and results were compared with experiment results with 5-holes Pitot tube from other towing tank. The model ship was KVLCC2, of which hull design and dimension are open to public. The scale of the model ship was 1/100, and the Froude number was 0.142 in the design speed. SPIV results showed good agreement with existing results and have advantages such as depiction of turbulence properties and reduction of the experiment-operating time
Novel morphologic and genetic analysis of cancer cells in a 3D microenvironment identifies STAT3 as a regulator of tumor permeability barrier function
Tumor permeability is a critical determinant of drug delivery and sensitivity, but systematic methods to identify factors that perform permeability barrier functions in the tumor microenvironment are not yet available. Multicellular tumor spheroids have become tractable in vitro models to study the impact of a three-dimensional (3D) environment on cellular behavior. In this study, we characterized the spheroid-forming potential of cancer cells and correlated the resulting spheroid morphologies with genetic information to identify conserved cellular processes associated with spheroid structure. Spheroids generated from 100 different cancer cell lines were classified into four distinct groups based on morphology. In particular, round and compact spheroids exhibited highly hypoxic inner cores and permeability barriers against anticancer drugs. Through systematic and correlative analysis, we reveal JAK-STAT signaling as one of the signature pathways activated in round spheroids. Accordingly, STAT3 inhibition in spheroids generated from the established cancer cells and primary glioblastoma patient-derived cells altered the rounded morphology and increased drug sensitivity. Furthermore, combined administration of the STAT3 inhibitor and 5-fluorouracil to a mouse xenograft model markedly reduced tumor growth compared with monotherapy. Collectively, our findings demonstrate the ability to integrate 3D culture and genetic profiling to determine the factors underlying the integrity of the permeability barrier in the tumor microenvironment, and may help to identify and exploit novel mechanisms of drug resistance. © 2015 American Association for Cancer Research1771sciescopu
Cellular Biocompatibility and Biomechanical Properties of N-carboxyethylchitosan/nanohydroxyapatite Composites for Tissue-engineered Trachea
Effect of a plasma polymerised linalyl acetate dielectric on the optical and morphological properties of an n-type organic semiconductor
Thin films of the n-type, organic semiconductor PDI-8CN2 were thermally evaporated on two different dielectric surfaces and their optical and morphological properties investigated using Variable Angle Spectroscopic Ellipsometry (VASE) and Atomic Force Microscopy (AFM), respectively. The two dielectric surfaces used were SiO2 and a plasma polymer derived from the non-synthetic monomer linalyl acetate. The characterisations were performed in order to assess the viability of plasma polymerised linalyl acetate (PLA) thin films as dielectric layers in future Organic Field-Effect Transistor (OFET) devices. These studies resulted in determination of the optical profiles (refractive index and extinction coefficient) in the UV-Vis band of PDI-8CN2 grown on SiO2 and an observation of uniaxial anisotropy in the organic semiconductor. This information is useful for the design of opto-electronic devices using PDI-8CN2 layers. Variations in morphological properties and small variations optical properties were found when the PDI-8CN2 films were grown on PLA layers, and attributed to the change in surface chemistry between dielectrics
Fission Yeast F-box Protein Pof3 Is Required for Genome Integrity and Telomere Function
The Skp1-Cullin-1/Cdc53-F-box protein (SCF) ubiquitin ligase plays an important role in various biological processes. In this enzyme complex, a variety of F-box proteins act as receptors that recruit substrates. We have identified a fission yeast gene encoding a novel F-box protein Pof3, which contains, in addition to the F-box, a tetratricopeptide repeat motif in its N terminus and a leucine-rich-repeat motif in the C terminus, two ubiquitous protein–protein interaction domains. Pof3 forms a complex with Skp1 and Pcu1 (fission yeast cullin-1), suggesting that Pof3 functions as an adaptor for specific substrates. In the absence of Pof3, cells exhibit a number of phenotypes reminiscent of genome integrity defects. These include G2 cell cycle delay, hypersensitivity to UV, appearance of lagging chromosomes, and a high rate of chromosome loss. pof3 deletion strains are viable because the DNA damage checkpoint is continuously activated in the mutant, and this leads to G2 cell cycle delay, thereby preventing the mutant from committing lethal mitosis. Pof3 localizes to the nucleus during the cell cycle. Molecular analysis reveals that in this mutant the telomere is substantially shortened and furthermore transcriptional silencing at the telomere is alleviated. The results highlight a role of the SCF(Pof3) ubiquitin ligase in genome integrity via maintaining chromatin structures