409 research outputs found

    Fundamental equation based on pole allocation for interstory seismic isolation of buildings

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    An inverse problem is formulated based on the pole allocation method in control theory, for a building with an interstory seismic isolation system. The structural system is simplified as a three-degree-of-freedom lumped-mass shear model. The natural frequencies and the corresponding damping ratios in the three vibration modes are set as the initial control target. To achieve this target, the introduced solution provides the natural frequencies of the lower substructure, upper substructure, and isolator with damper capacity. It simultaneously provides the mass distribution for the three lumped masses. The closed-form expression clarifies how the isolator's natural frequency and damper's capacity are related to the dominant natural frequencies of both the substructures and to the target modal damping ratios. The mathematical expression explains the trade-off relationship between the damping ratios of the lower and upper substructures. Furthermore, the solution is applied to directly estimate the damping effect by a tuned mass damper. The inverse problem approach is effective for understanding the general and essential dynamic characteristics of interstory seismic isolation

    CPPD crystal deposition disease of the cervical spine: A common cause of acute neck pain encountered in the neurology department

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    Background: Calcium pyrophosphate dihydrate (CPPD) crystal deposition disease is one of the most common forms of crystal-associated arthropathy in the elderly. However, CPPD deposition on the cervical spine is less well known, and only a limited number of cases have been reported to date. Here, we report our recent clinical experience with CPPD crystal deposition disease of the cervical spine and describe the clinical features of this disease. Methods: Fourteen patients with clinically diagnosed CPPD crystal deposition disease of the cervical spine at our department during the period from January 2005 to December 2008 were analyzed retrospectively. Results: Patients ranged in age from 54 to 92 (mean +/- SD, 77.5 +/- 8.5). Chief symptoms of patients were acute posterior neck pain and fever. All patients had markedly restricted neck rotation. Serum CRP level was highly elevated in all patients (10.16 +/- 5.35 mg/dL). Computed tomography of the cervical spine demonstrated linear calcific deposits in the transverse ligament of atlas (crowned dens syndrome) in all patients. Calcific deposits were also found in other periodontoid structures and the ligamenta flava in some patients. Posterior neck pain, fever, and increased serum inflammatory indicators were relieved within 1 to 3 weeks by nonsteroidal antiinflammatory drugs (NSAIDs) or a combination of NSAIDs and prednisolone. Most of the patients were misdiagnosed as having other diseases before consultation. Conclusions: CPPD crystal deposition disease of the cervical spine is one of the most common underrecognized causes of acute neck pain in the neurology department, especially in elderly patients.ArticleJOURNAL OF THE NEUROLOGICAL SCIENCES. 296(1-2):79-82 (2010)journal articl

    A novel nonsense mutation in the TITF-1 gene in a Japanese family with benign hereditary chorea

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    A Japanese family with a novel nonsense mutation in the TITF-1 gene (p.Y98X) is described. The proband showed severe generalized chorea, delayed motor development, subnormal intelligence, congenital hypothyroidism, bronchial asthma, and a history of pulmonary infection, all of which are characteristic features of Brain-Thyroid-Lung syndrome. On the other hand, her brother and mother showed a mild benign hereditary chorea (BHC) phenotype with congenital hypothyroidism. Intrafamilial phenotypic variation is common in BHC/Brain-Thyroid-Lung syndrome and suggests the existence of other genetic or environmental factors regulating TITF-1 function. Although choreic movement in BHC/Brain-Thyroid-Lung syndrome is recognized as non-progressive, the proband showed re-exacerbation of choreic movement at puberty. The dopamine agonist, ropinirole hydrochloride, reduced her choreic movements, suggesting that levodopa and/or dopamine agonists may compensate for underdeveloped dopaminergic pathways in this disorder.ArticleJOURNAL OF THE NEUROLOGICAL SCIENCES. 313(1-2):189-192 (2012)journal articl

    Distribution and stoichiometry of Al, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb in the East China Sea

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    The dissolved (d) and total dissolvable (td) trace metals were determined in seawater samples collected from the East China Sea (ECS). Labile particulate (lp) species was calculated as td minus d, and the sectional and vertical distributions of d and lp trace metals were evaluated. The surface concentrations of dAl, dCo, dNi, dCu, and dPb were higher in the continental shelf region than in the Kuroshio region. lpAl and lpFe were the dominant species below a depth of 400 m, and a strong positive correlation was observed between them in the Kuroshio region. The enrichment factor (EF) against crustal abundance was calculated for the purpose of estimating the origin of dMs in the ECS. The EF(dFe) was close to unity. These results suggest that both lpFe and dFe are dominated by crustal sources. The other elements had high EF, indicating significant contributions from other sources. EF(dPb) was close to the enrichment factor in aerosol, suggesting atmospheric input from anthropogenic sources. The dM/P ratios were calculated to investigate the validity of the extended Redfield ratio in the ECS. The Mn/P, Co/P, Cu/P, Zn/P, and Cd/P ratios in shallow water (< 200 m) were within the same order of magnitude as those in phytoplankton. In contrast, the Al/P and Fe/P ratios were, respectively, 27 and 213 times higher in phytoplankton compared to those in shallow water. These results suggest that dFe is a potential limiting factor for biological production, although it is not exhausted in surface water

    Upper limb neuropathy such as carpal tunnel syndrome as an initial manifestation of ATTR Val30Met familial amyloid polyneuropathy

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    This is an electronic version of an article published in Amyloid 2010, Vol. 17, No. 1 : Pages 32-35. Amyloid is available online at: http://informahealthcare.com/doi/pdf/10.3109/13506121003619369We report here two patients with amyloidogenic transthyretin (ATTR) Val30Met familial amyloid polyneuropathy (FAP) who developed numbness in both hands and were diagnosed as having bilateral carpal tunnel syndrome (CTS). In both patients systemic TTR amyloidosis consisting of polyneuropathy affecting both upper and lower limbs and/or autonomic dysfunction gradually appeared after surgery for CTS. Although CTS associated with TTR amyloidosis has been known as an initial symptom in some patients with ATTR non-Val30Met FAP and those with senile systemic amyloidosis, this is the first report of ATTR Val30Met FAP patients starting with upper limb neuropathy including CTS-like symptoms. It is also notable that both patients had no genealogical relationship with two Japanese endemic foci of this disease.ArticleAMYLOID. 17(1):32-35 (2010)journal articl

    Left ventricular deformation and torsion assessed by speckle-tracking echocardiography in patients with mutated transthyretin-associated cardiac amyloidosis and the effect of diflunisal on myocardial function

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    AbstractBackgroundMutated transthyretin-associated (ATTRm) amyloidosis with heart failure is associated with decreased longitudinal left ventricular (LV) myocardial contraction, as measured by strain Doppler echocardiography. We sought to clarify whether speckle-tracking echocardiography (STE) would provide useful information in patients with ATTRm cardiac amyloidosis.MethodsOne hundred twenty-three consecutive patients with ATTRm amyloidosis were divided into 3 groups. Group 1 had no evidence of cardiac involvement (n=47), group 2 had heart involvement but no congestive heart failure (CHF) and/or serum brain natriuretic peptide (BNP) levels <100pg/mL (n=35), and group 3 had heart involvement and CHF and/or serum BNP levels ≥100pg/mL (n=41). All patients underwent standard 2-dimensional (2D), Doppler echo, and STE.ResultsBy standard 2D and Doppler echo, differences in parameters were only apparent between group 3 and groups 1 and 2. Global circumferential strains by STE at each LV level and LV torsion were different between group 1 and groups 2 and 3, but not between group 2 and group 3. In contrast, global longitudinal LV strain showed significant intergroup differences (−17.3±2.3%, −13.3±2.3%, −9.9±3.3% for groups 1 to 3, respectively, P<0.0001). Radial strain also showed significant intergroup differences for each basal LV segment. Among 41 patients who could have been followed up after 1year, 34 patients with diflunisal treatment had shown improvement in apical rotation and torsion without deterioration in multidirectional strains.ConclusionATTRm cardiac amyloidosis is characterized by progressive impairment in longitudinal and basal LV radial function when global circumferential shortening and torsion remain unchanged

    A Young Man with Anti-NMDAR Encephalitis following Guillain-Barré Syndrome

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    A 19-year-old man developed rapidly progressive muscle weakness and dysesthesia in the extremities, and dyspnea after a flu-like episode. Nerve conduction studies showed reduced motor nerve conduction velocities with conduction block, and sensory nerve action potentials could not be evoked. The patient was diagnosed as having Guillain-Barré syndrome (GBS), and was treated with 2 cycles of intravenous immunoglobulin (IVIg) therapy and was assisted by mechanical ventilation. During the recovery course of the illness, he experienced several attacks of psychomotor agitation from the 37th hospital day, and generalized tonic convulsive seizures suddenly developed on the 42nd hospital day. Brain MRI showed high-intensity lesions in the bilateral thalamus and medial temporal lobes. The convulsions were controlled by continuous thiopental infusion (until the 50th hospital day) and mechanical ventilation (until the 84th hospital day). Intravenous methylprednisolone pulse therapy (1,000 mg/day) for 3 days followed by dexamethasone (16 mg/day) was added. After relief of convulsive seizures, prominent orolingual dyskinesia appeared, and on MRI marked atrophy of the bilateral medial temporal lobes was seen. Anti-N-methyl-D-aspartate receptor (NMDAR) antibodies in serum and cerebrospinal fluid were positive on the 92nd hospital day. Anti-NMDAR encephalitis usually affects young females but a small number of male cases with this disease have been reported. Our male patient was unique in having GBS, a post-infectious autoimmune disease, as a preceding disease, suggesting that anti-NMDAR encephalitis itself is caused by a parainfectious autoimmune mechanism
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