Intermediate band solar cell with extreme broadband spectrum quantum efficiency.

We report, for the first time, about an intermediate band solar cell implemented with InAs/AlGaAs quantum dots whose photoresponse expands from 250 to ∼6000 nm. To our knowledge, this is the broadest quantum efficiency reported to date for a solar cell and demonstrates that the intermediate band solar cell is capable of producing photocurrent when illuminated with photons whose energy equals the energy of the lowest band gap. We show experimental evidence indicating that this result is in agreement with the theory of the intermediate band solar cell, according to which the generation recombination between the intermediate band and the valence band makes this photocurrent detectable.

An order-N electronic structure theory with generalized eigenvalue equations and its application to a ten-million-atom system.

A linear algebraic theory called the 'multiple Arnoldi method' is presented and realizes large-scale (order-N) electronic structure calculations with generalized eigenvalue equations. A set of linear equations, in the form of (zS - H)x = b, are solved simultaneously with multiple Krylov subspaces. The method is implemented in a simulation package ELSES (www.elses.jp) with tight-binding-form Hamiltonians. A finite-temperature molecular dynamics simulation is carried out for metallic and insulating materials. A calculation with 10(7) atoms was realized by a workstation. The parallel efficiency is shown up to 1024 CPU cores.

Four-point correlation function of a passive scalar field in rapidly fluctuating turbulence: Numerical analysis of an exact closure equation.

A numerical analysis is made on the four-point correlation function in a similarity range of a model of two-dimensional passive scalar field ψ advected by a turbulent velocity field with infinitely small correlation time. The model yields an exact closure equation for the four-point correlation Ψ{4} of ψ, which may be casted into the form of an eigenvalue problem in the similarity range. The analysis of the eigenvalue problem gives not only the scale dependence of Ψ{4} , but also the dependence on the configuration of the four points. The numerical analysis gives S4(R)∝R{ζ{4}} in the similarity range in which S2(R)∝R{ζ{2}} , where S_{N} is the structure function defined by S{N}(R)≡⟨[ψ(x+R)-ψ(x)]{N} and ζ{4}≠2ζ{2} . The estimate of ζ_{4} by the numerical analysis of the eigenvalue problem is in good agreement with numerical simulations so far reported. The agreement supports the idea of universality of the exponent ζ{4} in the sense that ζ_{4} is insensitive to conditions of ψ outside the similarity range. The numerical analysis also shows that the correlation C(R,r)≡[ψ(x+R)-ψ(x)]{2}[ψ(x+r)-ψ(x)]{2}> is stronger than that given by the joint-normal approximation, and scales like C(R,r)∝(r/R){χ} for r/R<<1 with R and r in the similarity range, where χ is a constant depending on the angle between R and r .

Novel algorithm of large-scale simultaneous linear equations.

We review our recently developed methods of solving large-scale simultaneous linear equations and applications to electronic structure calculations both in one-electron theory and many-electron theory. This is the shifted COCG (conjugate orthogonal conjugate gradient) method based on the Krylov subspace, and the most important issue for applications is the shift equation and the seed switching method, which greatly reduce the computational cost. The applications to nano-scale Si crystals and the double orbital extended Hubbard model are presented.

Effect of weight bearing on recovery from nerve injury in skeletal muscle.

We examined the effect of weight bearing (WB) on muscle recovery after nerve injury. Rats were housed in individual cages for 2 wk under WB or hindlimb suspension (HS) after being subjected to sciatic nerve compression for 1 wk. Sham operated on rats served as controls (sham group). We used 31P- and 19F-nuclear magnetic resonance spectroscopy combined with histochemical, physiological, and biochemical techniques to assess the outcome in the three groups. Creatine kinase-BB (CK-BB) mRNA levels expression, CK activity, and type I fiber density in the WB group were elevated compared with those in the HS group. In addition, sciatic functional index, tetanic tension, energy state, and local circulation dynamics of the WB group were greater than those of the HS group. These results suggested that WB plays an important role in muscle regeneration, inhibits the reduction of CK activity, and facilitates the activation of neural recovery, energy state, and local circulation dynamics.

On-site diagnosis of H. pylori infection by urine.

We have recently developed an on-site diagnostic kit for H. pylori infection using urine (utilizing immunochromatographic method employing a nitrocellulose membrane coated by extracted H. pylori antigen). Accordingly, we investigated its usefulness in 155 consecutive dyspeptic patients using the 13C urea breath test as a gold standard and further compared its performance with two commercially available rapid diagnostic kits that use whole blood (Helisal Rapid Blood, and ImmunoCard H. pylori). As the results, the urine based on-site diagnostic kit provided 95.9% sensitivity and 87.9% specificity with 92.9% accuracy, which were comparable or even better than that of both rapid whole blood tests, suggesting its usefulness in screening of H. pylori infection.

[A case of visual perseveration attack caused by transverse-sigmoid sinus dural arteriovenous fistula].

A case of visual perseveration attack in the right superior quadrantic visual field caused by left transverse-sigmoid sinus dural arteriovenous fistula (AVF) was reported. A 75-year old right-handed man noticed that when he saw an object, the image sometimes persisted even after he looked away or the object was removed. The palinoptic images always appeared in the right superior quadrant visual field, consisted of a row of multiple objects all identical to the real one in shape, and were accompanied by photopsia. The palinoptic images disappeared within a few minutes. He was neurologically normal and showed no hemianopia or quadrantanopia on admission. EEG showed no epileptic discharge. CT scanning of the brain revealed a small high density area in the left occipital lobe. MRI demonstrated hyperintensity in the left inferior occipital lobe corresponding to the lower part of Brodmann's areas 18 and 19 on T2 weighted image and flow-voids caused by the dilated left occipital artery. 99mTc-ECD SPECT disclosed a decrease of regional cerebral blood flow in the left occipital lobe. Cerebral angiography revealed dural AVF fed by three branches of the left occipital artery and another branch of the left ascending pharyngeal artery with retrograde drainage into the left transverse sinus, sigmoid sinus, and dilated cortical veins. The left transverse and sigmoid sinuses were occluded. Visual perseveration disappeared following the treatment of the dural AVF by transarterial embolization. Because the lesions on MRI and SPECT improved after the treatment, these lesions were considered to represent not infarction but vasogenic edema due to venous congestion. We emphasized the role of the left inferior occipital lesion including the secondary visual cortex (Brodmann's areas 18 and 19) as the cause of visual perseveration in the right superior quadrantic visual field.

Venodilatory effect of pranidipine, a calcium channel blocker, monitored with perfluorocarbon in vivo (19)F-NMR spectroscopy.

We previously reported that the (19)F-NMR signal intensity of perfluorocarbon was increased by a venodilator, nitroglycerine, and decreased by an arteriodilator, hydralazine. In the present study, we demonstrated that pranidipine, a calcium channel blocker, increased the intensity of the FC-43 signal, while nifedipine, a prototype of calcium channel blockers, did not. These results suggest that pranidipine dilates the venous system in contrast to nifedipine.

A Case of Reversed Ophthalmic Artery Flow without Occlusion of the Internal Carotid Artery.

Background: We report a case of reversed ophthalmic artery (OA) flow showing neither occlusion of the internal carotid artery (ICA) nor ophthalmic symptoms.Case: An 82-year-old man had transient blindness in both eyes. After left carotid endarterectomy, ophthalmic symptoms improved in the right and left eyes. Afterwards, he had a relapse in the left eye.Results: There was no unusual impression in the ophthalmic examinations, but color Doppler imaging showed reduced flow in the left OA, reversal of flow direction in the right OA. The central retinal artery (CRA) and short posterior ciliary arteries (SPCA) were not detected in the left eye but were detected in the right eye. Digital subtraction angiography demonstrated that the right OA was not contrasted with the right ICA, despite there being no stenosis or occlusion of the right ICA.Conclusions: We suggest that carotid surgery may affect the ocular circulation of the opposite side, and reversed OA flow as a collateral pathway from the external carotid artery may occur in the absence of carotid artery stenosis. Good circulation of the CRA and SPCA may preclude manifestation of ophthalmic symptoms even if the OA flow is reversed.

[A case of reversed ophthalmic artery flow without occlusion of the internal carotid artery].

BACKGROUND: We report a case of reversed ophthalmic artery (OA) flow showing neither occlusion of the internal carotid artery (ICA) nor ophthalmic symptoms. CASE: An 82-year-old man had transient blindness in both eyes. After left carotid endarterectomy, ophthalmic symptoms improved in the right and left eyes. Afterwards, he had a relapse in the left eye. RESULTS: There was no unusual impression in the ophthalmic examinations, but color Doppler imaging showed reduced flow in the left OA, reversal of flow direction in the right OA. The central retinal artery (CRA) and short posterior ciliary arteries (SPCA) were not detected in the left eye but were detected in the right eye. Digital subtraction angiography demonstrated that the right OA was not contrasted with the right ICA, despite there being no stenosis or occlusion of the right ICA. CONCLUSIONS: We suggest that carotid surgery may affect the ocular circulation of the opposite side, and reversed OA flow as a collateral pathway from the external carotid artery may occur in the absence of carotid artery stenosis. Good circulation of the CRA and SPCA may preclude manifestation of ophthalmic symptoms even if the OA flow is reversed.

Effects of denervation on energy metabolism of rat hindlimb muscles: application of (31)P-MRS and (19)F-MRS.

We studied the effects of denervation on the energy metabolism and peripheral circulation dynamics of rat hindlimb muscles during and after exercise. The sciatic nerves of male Wistar rats were cut to produce denervation. Energy metabolism was assessed by phosphorus-31 magnetic resonance spectroscopy (MRS), and circulation by fluorine-19 MRS. Exercise of rat hindlimb muscles was induced by electrical stimulation at 40 Hz. The inorganic phosphate (Pi) / ¿Pi + phosphocreatine (PCr)¿ ratio, an indicator of the energy level, was 0.795 immediately after denervation. The ratios 4 and 8 weeks after denervation were 0.870 and 0.853, respectively. The intracellular pH during the 4 min after initiation of stimulation was significantly reduced 4 and 8 weeks after denervation compared with the value immediately after denervation. The signal strength of the research perfluoro-carbon (FC-43; perfluorotributylamine) a measure of circulation dynamics, increased to 167% in controls during exercise, but an increase of only 134% was seen in rats 8 weeks after denervation. These results showed that the energy supply and circulation dynamics in denervated atrophic muscles decreased during exercise compared with findings in control muscles.

Effect of peripheral nerve injury on nuclear magnetic resonance relaxation times of rat skeletal muscle.

RATIONALE AND OBJECTIVES: The authors evaluate the changes in magnetic resonance (MR) relaxation times of rat skeletal muscles in vivo after nerve injury and during neural recovery, and determine the major determinants of relaxation times. MATERIALS: Magnetic resonance relaxation times, blood volume, and water and fat content were examined after nerve injury and during recovery with time course. RESULTS: Nerve injury led to longer T2 values compared with controls, but there were no significant changes in T1 values. After the initial prolongation of T2 after nerve injury, no changes were observed. Neural recovery resulted in a return of T2 values to normal. The time course of changes in blood volume was similar to that of changes in T2, and T2 values were correlated strongly with 19-fluorine-MR spectroscopy estimates of blood volume (r2 = 0.94). CONCLUSIONS: T2 values may be useful to monitor recovery after nerve injury and may be related to the blood volume in skeletal muscle.

Time course of recovery from nerve injury in skeletal muscle: energy state and local circulation.

This study examined the time course of recovery from nerve injury on energy state assessed by phosphorus-31 magnetic resonance spectroscopy and local circulation dynamics by fluorine-19 magnetic resonance spectroscopy in skeletal muscles of rats. The hindlimb muscles that had undergone unilateral sciatic nerve compression for 2 wk (CN) were compared with sham-operated (SO) muscles and with muscles that had the compression removed after 2 wk and were allowed to recover for 4 wk (R4) or for 6 wk (R6). The energy state and local circulation dynamics of CN muscles were less than those of SO muscles (P < 0.01). The energy state of R4 muscles remained at levels similar to CN muscles, whereas the local circulation dynamics improved but not back to SO values. In R6 muscles, both parameters returned to SO values. These results showed that the recovery processes of circulation precede those of energy state in skeletal muscles.

Effects of vasodilators on the signal intensity of perfluorocarbon monitored by in vivo 19F-NMR spectroscopy.

The effects of vasodilators on peripheral vessels were examined by monitoring the 19F-NMR signal of perfluorocarbon in vivo. Nitroglycerin, a venodilator that acts mainly on venous smooth muscle, increased the signal intensity of FC-43, whereas hydralazine, a typical arteriolar dilator that acts on arteriolar smooth muscle, decreased the signal intensity. These results indicate that the in vivo effects of vasodilators on smooth muscles of the venous and arterial systems are reflected by their effects on the signal intensity of FC-43.

Le(b), a novel glycosphingolipid antigen of human distal colorectal cancer.

The expression of the glycosphingolipid antigens was investigated in human colorectal carcinomas and adjacent normal tissues obtained by surgical operation from six patients. The glycosphingolipids, including both non-acidic glycolipid and ganglioside, were extracted from the tissue specimens and separated by two-dimensional thin-layer chromatography of silica gel. A novel neutral glycolipid antigen migrating lower than Le(a) blood group antigen was detected in the cancerous tissues of all six patients, but not in normal regions in the same patients. The structure of the glycosphingolipid was partially characterized by gas chromatography and gas chromatography/mass spectrometry of alditol acetate and negative ion fast atom bombardment mass spectrometry (FAB/MS) of the intact glycolipid, and TLC-immunostaining with monoclonal anti-Le(a), -Le(b), -sialyl Le(a), and -Le(Y) antibody, respectively. The novel neutral glycosphingolipid in colorectal cancer was identified to be the III(4)IV(2)Fuc(2)Lc(4)Cer, Le(b) antigen of the human Lewis blood system. Direct FAB/MS showed the ceramide was composed mainly of 2-hydroxy tetradecanon and C18 phytosphingosine. In such individuals, the expression of Le(b) antigen in normal tissues is absent or minimal. Based on this study, we suggest that this Le(b) antigen may be a human distal colorectal cancer-associated antigen, which will be helpful for diagnosis and treatment of distal colorectal cancer.

[Role of tripeptide Arg-Gly-Asp (RGD) on adhesiveness of human pancreatic cancer cell, PANC-1 to extracellular matrix].

Tumor cell invasion and metastasis are likely to be complex processes involving a variety of cell surface receptors mediating interactions with a number of extracellular matrix molecules, including fibronectin, laminin, and collagen. We have applied this interaction of receptors for specific adhesive substrates in vitro, using specific monoclonal antibody and biologically active synthetic peptides with human pancreatic carcinoma cell, PANC-1. Tripeptide Arg-Gly-Asp (RGD) inhibited adhesion on PANC-1 cells to fibronectin but less effective in blocking adhesion to laminin and collagen, although anti beta 1-integrin antibody significantly inhibited adhesion of fibronectin but less inhibited to laminin, collagen. Our studies emphasize the importance of synthetic tripeptide RGD in adhesion on PANC-1 to extracellular matrix protein, as well as indicating the specificity of cell surface receptor, beta 1 integrin.

[Role of carbohydrate antigens in cell-cell and cell to extracellular matrix adhesion on pancreatic cancer].

We investigated the variable adhesiveness of pancreatic cancer cells by glycosylation inhibitor to elucidate the role of carbohydrate antigens in cell-cell and cell to extracellular matrix adhesion. Various carbohydrate antigens were strongly expressed on pancreatic cancer cell (SW1990) by ELISA, and these expression correlated to its in vitro invasiveness and in vivo metastatic potential. Cellular adhesion to Matrigel, laminin and collagen type IV and homotypic cellular aggregation in SW1990 were enhanced by reducing O-linked glycosylation with its inhibitor (Bzl-GalNAc), and these effect were reversed by additional purified mucins. These results suggested that O-linked glycoproteins on SW1990 cell surface may inhibit its adhesiveness to the substratum and aggregation properties by hindering surface receptors, and this variability of adhesiveness induced by altered glycosylation may have an another important role in highly metastatic potential of well glycosylated cancer cells.

[Establishment and characterization of a human breast cancer cell line, OCUB-1].

We established new human breast cancer cell line, OCUB-1 derived from the pleural effusion of 53-year old female with recurrent breast cancer. Two sub-cell lines were also established with cloning technique from OCUB-1. Investigating the differences of characteristics between OCUB-1M and 1F, OCUB-1M shows a monolayered growing and OCUB-1F grows in floating. OCUB-1M and 1F revealed Modo 84 and 41 by chromosomal analysis and flow cytometric analysis showed OCUB-1M had twice amount of DNAs as -1F. OCUB-1M revealed higher expression of E-cadherin and laminin receptor against-1F, and activity of 92kDa type IV collagenase could be seen only in OCUB-1M. Estorogen and progesteron receptor were negative in either OCUB-1M and -1F, and no production of tumor markers in the spent media (CEA, CA19-9, CA15-3 and NCC-ST439) was detected in both cells. Both cells could be hetero-transplanted in nude mice, but they showed different histology.

[Clinical, laboratorial, and therapeutic aspects of 46 children with Henoch-Schönlein purpura]. / Aspectos clínicos, laboratoriais e terapêuticos de 46 crianças com púrpura de Henoch-Schönlein.

Forty-six children with Henoch-Schönlein purpura were studied.Their clinical manifestations included palpable purpura in 100%, subcutaneous edema in 30%, arthritis/arthralgia in 78%, gastrointestinal involvement in 56% and renal abnormalities in 30%. Serum IgA was elevated in 12%, ASLO titers in 27% and microscopic hematuria and proteinuria were detected in 30% of the children, including two with nephrotic syndrome. Treatment with non-steroidal antiinflammatory drugs or corticosteroid was indicated in 43% of the children. Recurrence of the disease was observed in 22% and the prognosis seems to be related to severity of renal involvement.

Germinoma of the medulla oblongata--case report.

A 32-year-old female presented with medulla oblongata germinoma manifesting as numbness in the extremities. Computed tomography demonstrated a mass in the medulla oblongata expanding into the fourth ventricle. The tumor was partially removed. Immunohistochemical staining of the tumor specimen demonstrated large epithelioid cells positive for placental alkaline phosphatase, and syncytiotrophoblastic cells positive for beta subunit of human chorionic gonadotropin. Some epithelioid cells were also positive for cytokeratin. She received 44 Gy of irradiation to the posterior fossa and 20 Gy whole spinal irradiation. No signs of recurrence have occurred for 9 years. Patients with medulla oblongata germ cell tumor are comparatively older than those with other intracranial germ cell tumors and have two X chromosomes. All tumors were diagnosed as germinoma, and caused symptoms of involvement of the lower cranial nerves and the lower brain stem without pyramidal tract signs.