Comparison of electrode structures and photovoltaic properties of porphyrin-sensitized solar cells with TiO2 and Nb, Ge, Zr-added TiO2 composite electrodes

Electrode structures and photovoltaic properties of porphyrin-sensitized solar cells with TiO2 and Nb-, Ge-, and Zr-added TiO2 composite electrodes were examined to disclose the effects of partial substitution of Ti atom by the other metals in the composite electrodes. The TiO2 and Nb-, Ge-, and Zr-added TiO2 composite electrodes were prepared by sol-gel process using laurylamine hydrochloride as a template for the formation of micellar precursors yielding well-defined mesoporous nanocrystalline structures, as in the cases of the formation of silica and titania tubules and nanoparticles by the templating mechanism. The TiO2 and Nb-, Ge-, and Zr-added TiO2 composite electrodes were characterized by transmission electron microscopy, BET surface area analysis, X-ray diffraction analysis, Raman spectroscopy, and impedance measurements. The TiO2 anatase nanocrystalline structure is retained after doping a small amount (5 mol %) of Nb, Ge, or Zr into the TiO2 structure, suggesting the homogeneous distribution of the doped metals with replacing Ti atom by the doped metal. The power conversion efficiency of the porphyrin-sensitized solar cells increases in the order Zr-added TiO2 (0.8%) < Nb-added TiO2 (1.2%) < TiO2 (2.0%) < Ge-added TiO2 cells (2.4%) under the same conditions. The improvement of cell performance of the Ge-added TiO2 cell results from the negative shift of the conduction band of the Ge-added TiO2 electrode. The Ge-added TiO2 cell exhibited a maximum power conversion efficiency of 3.5% when the porphyrin was adsorbed onto the surface of the Ge-added TiO2 electrode with a thickness of 4 microm in MeOH for 1 h.

Myocardial interstitial choline and glutamate levels during acute myocardial ischaemia and local ouabain administration

AIM

Noradrenaline (NA) uptake transporters are known to reverse their action during acute myocardial ischaemia and to contribute to ischaemia-induced myocardial interstitial NA release. By contrast, functional roles of choline and glutamate transporters during acute myocardial ischaemia remain to be investigated. Because both transporters are driven by the normal Na+ gradient across the plasma membrane in a similar manner to NA transporters, the loss of Na+ gradient would affect the transporter function, which would in turn alter myocardial interstitial choline and glutamate levels. The aim of the present study was to examine the effects of acute myocardial ischaemia and the inhibition of Na+,K+-ATPase on myocardial interstitial glutamate and choline levels.

METHODS

In anaesthetized cats, we measured myocardial interstitial glutamate and choline levels while inducing acute myocardial ischaemia or inhibiting Na+,K+-ATPase by local administration of ouabain.

RESULTS

The choline level was not changed significantly by ischaemia (from 0.93 +/- 0.06 to 0.82 +/- 0.13 microm, mean +/- SE, n = 6) and was decreased slightly by ouabain (from 1.30 +/- 0.06 to 1.05 +/- 0.07 microm, P < 0.05, n = 6). The glutamate level was significantly increased from 9.5 +/- 1.9 to 34.7 +/- 6.1 microm by ischaemia (P < 0.01, n = 6) and from 8.9 +/- 1.0 to 15.9 +/- 2.3 microm by ouabain (P < 0.05, n = 6). Inhibition of glutamate transport by trans-L-pyrrolidine-2,4-dicarboxylate (t-PDC) suppressed ischaemia- and ouabain-induced glutamate release.

CONCLUSION

Myocardial interstitial choline level was not increased by acute myocardial ischaemia or by Na+,K+-ATPase inhibition. By contrast, myocardial interstitial glutamate level was increased by both interventions. The glutamate transporter contributed to glutamate release via retrograde transport.

Morphological studies on the ageing and osteoarthritis of the articular cartilage in C57 black mice

PURPOSE

To study the cause and mechanism of joint degeneration in osteoarthritis, through histopathological and ultrastructural-histochemical experiments on the articular cartilage of the knees of the C57 black mouse.

METHODS

192 C57 black mice and a control group of 64 C57BL/6J mice were used in this study. The left and right knee articular capsules of the joints were removed and stained. Each articular cartilage sample was examined and osteoarthritic changes were assessed using a transmission electron microscope. The severity of osteoarthritis in the knee joint cartilage of C57 black mice was histologically assessed using a classification system described by Okabe, based on Maier's system.

RESULTS

The incidence and the severity of osteoarthritis gradually increased with age; the incidence increased from 20% at 2 months to 80% at 16 months. Irreversible changes appeared at an advanced stage, and the process of degeneration was quite similar to that in human osteoarthritis. Through transmission electron microscopy, we observed poorly developed Golgi apparatus, markedly increased intracellular microfilaments, decreased proteoglycan granules, and broken collagen networks in all stages of osteoarthritis. By contrast, Golgi apparatus and other organelles were well developed in histologically normal mice of all ages. Proteoglycan granules, which mainly consisted of keratan sulphate, were observed; collagen networks were maintained.

CONCLUSION

Disturbed protein transport and sugar synthesis in chondrocytes, caused by the deficient development of the Golgi apparatus, could result in degenerative changes in articular cartilage. The structure and function of the matrix were maintained mainly because of the continued presence of keratan sulphate.

Activation of distinct signal transduction pathways in hypertrophied hearts by pressure and volume overload

OBJECTIVE

Two types of hemodynamic overload, pressure and volume overload, result in morphologically distinct types of cardiac remodeling. We explored the possibility that distinct hemodynamic overload may differentially activate the signal transduction pathway.

METHODS

Pressure and volume overload were induced by thoracic aortic banding and carotid-jugular shunt formation in rabbits, respectively. Phosphorylation activities of mitogen-activated protein (MAP) kinase families, Akt, and signal transducer and activator of transcription (STAT) 3 in the left ventricular myocardium were determined by Western blotting using phospho-specific antibodies and were compared between hypertrophied hearts by pressure and volume overload.

RESULTS

Pressure and volume overload produced concentric and eccentric cardiac hypertrophy in rabbits, respectively. In pressure-overloaded hearts, extracellular signal-regulated kinase (ERK) 1/2, p38 MAP kinase, and STAT3 were transiently activated prior to hypertrophic changes. In contrast, activation of ERK1/2, but not p38 MAP kinase and STAT3, was observed only at 12 weeks after shunt surgery. Pressure overload evoked short and biphasic activation of Akt at 15 min and 1 day after aortic banding. In contrast, volume overload induced sustained activation of Akt from 1 day to 1 week. Concordant phosphorylation of downstream targets of Akt, glycogen synthase kinase-3beta (GSK-3beta) and p70 ribosomal S6 kinase (p70(S6K)), in response to Akt activation was observed at 15 min after pressure overload. However in volume-overloaded hearts, phosphorylation of GSK-3beta and p70(S6K) was observed at 6 weeks and at 6 and 12 weeks, respectively, and was not coincident with Akt activation. These findings suggest that phosphorylation of GSK-3beta and p70(S6K) is regulated by an alternative pathway other than Akt in volume-overloaded hearts.

CONCLUSION

Pressure and volume overload-induced cardiac hypertrophy is associated with distinct patterns of activation of signal transduction pathways. These data may suggest that stimulus-specific heterogeneity in the signaling pathway plays a role in determining the type of cardiac hypertrophy.

Traumatic anterior dislocation of the hip associated with ipsilateral femoral shaft fracture in a child: a case report

Traumatic anterior dislocation of the hip joint in children is rare, and only one case with ipsilateral femoral fracture has been reported in Japan. We report a case of such dislocation and a review of the literature. The patient was a 31-month-old girl who was injured in a car accident while asleep on a tilted front passenger seat. Radiographic examination showed dislocation of the right obturator foramen and transverse fracture of the ipsilateral femoral shaft. The dislocation of the right hip was easily reduced without anaesthesia during radiography. We applied Bryant traction after reduction for 4 weeks, followed by cast application for 3 weeks. Walking with support and full weightbearing were permitted 14 weeks and 16 weeks after the injury, respectively. Radiography at 4.5 years after the injury showed a mildly enlarged right femoral head and femur overgrowth of approximately 8 mm. Magnetic resonance imaging showed no evidence of suspected avascular necrosis of the femoral head. The patient has no subjective or objective symptoms, and is able to engage in all usual activities. The detailed mechanism of the injury is unknown. We assume that the lower leg was dislocated through abduction during flexion, or abducent, external flexion, considering that the child was sleeping at the time of the accident. Since she was hurled to the back seat, it was assumed that strong external force was vertically added to the femur, which caused the abducent force.

Effects of ethane-1-hydroxy-1,1-diphosphonate on ossification of the posterior longitudinal ligament in Zucker fatty rats

PURPOSE

Using Zucker fatty rats as an animal model, we evaluate the effectiveness of ethane-1-hydroxy-1,1-diphosphonate on ossification of the posterior longitudinal ligament by histopathologically investigating the prodromal, early, and advanced stages of ossification of the spinal ligaments.

METHODS

73 Zucker fatty rats were allocated to the ethane-1-hydroxy-1,1-diphosphonate group (n=33) and the control group (n=40). The former group was fed ethane-1-hydroxy-1,1-diphosphonate daily. The feed was given starting 2 months after birth and continued until the rats were killed at 3 to 18 months later. Chemical analysis of the blood, radiographic tests, and histopathological examination were then conducted for both groups.

RESULTS

The results showed that ossification of the spinal ligaments involved excessive cartilage cell proliferation around areas affected by enthesitis; enlargement of the fibrocartilage tissue layer; ligament thickening; calcification of the matrix around the cartilage cells; and ossification of the spinal ligaments through enchondral ossification. Radiographic examinations showed that osteoproliferation in vertebral bodies in rats receiving ethane-1-hydroxy-1,1-diphosphonate was generally suppressed compared with controls, whereas histopathological examinations found no clear difference in cartilage cell proliferation in areas affected by enthesitis between the two groups, indicating the absence of calcification or osteo-proliferation in areas affected by enthesitis for the rats receiving ethane-1-hydroxy-1,1-diphosphonate.

CONCLUSION

Ethane-1-hydroxy-1,1-diphosphonate is effective in suppressing progressive ligament ossification.

Fatty acid metabolism assessed by 125I-iodophenyl 9-methylpentadecanoic acid (9MPA) and expression of fatty acid utilization enzymes in volume-overloaded hearts

BACKGROUND

The peroxisome proliferator-activated receptor (PPAR) alpha is a member of the nuclear receptor superfamily and regulates gene expression of fatty acid utilization enzymes. In cardiac hypertrophy and heart failure by pressure-overload, myocardial energy utilization reverts to the fetal pattern, and metabolic substrate switches from fatty acid to glucose. However, myocardial metabolism in volume-overloaded hearts has not been rigorously studied. The aim of the present study was to examine fatty acid metabolism and protein expressions of PPARalpha and fatty acid oxidation enzymes in volume-overloaded rabbit hearts.

METHODS

Volume-overload was induced by carotid-jugular shunt formation. Sham-operated rabbits were used as control. Chronic volume-overload increased left ventricular weight and ventricular cavity size, and relative wall thickness was decreased, indicating eccentric cardiac hypertrophy. (125)I-iodophenyl 9-methylpentadecanoic acid (9MPA) was intravenously administered, and animals were sacrificed at 5 min after injection. The 9MPA was rapidly metabolized to iodophenyl-3-methylnonanoic acid (3MNA) by beta-oxidation. Lipid extraction from the myocardium was performed by the Folch method, and radioactivity distribution of metabolites was assayed by thin-layer chromatography. The protein was extracted from the left ventricular myocardium, and levels of PPARalpha and fatty acid oxidation enzymes were examined by Western blotting.

RESULTS

Myocardial distribution of 9MPA tended to be more heterogeneous in shunt than in sham rabbits (P = 0.06). In volume-overloaded hearts by shunt, the conversion from 9MPA to 3MNA by beta-oxidation was faster than the sham-control hearts (P < 0.05). However, protein levels of PPARalpha and fatty acid utilization enzymes were unchanged in shunt rabbits compared with sham rabbits.

CONCLUSIONS

These data suggest that myocardial fatty acid metabolism is enhanced in eccentric cardiac hypertrophy by volume-overload without changes in protein expressions of PPARalpha and fatty acid utilization enzymes. Our data may provide a novel insight into the subcellular mechanisms for the pathological process of cardiac remodelling in response to mechanical stimuli.

Protein kinase C and extracellular signal regulated kinase are involved in cardiac hypertrophy of rats with progressive renal injury

Increased cardiovascular mortality is an unresolved problem in patients with chronic renal failure. Cardiac hypertrophy is observed in the majority of patients with chronic renal failure undergoing haemodialysis. However, the mechanisms, including signal transduction pathways, responsible for cardiac hypertrophy in renal failure remain unknown. We examined the subcellular localization of protein kinase C (PKC) isoforms and phosphorylation activities of 3 mitogen-activated protein (MAP) kinase families in hypertrophied hearts of progressive renal injury rat model by subtotal nephrectomy (SNx). We also examined the effects of a novel angiotensin II type-1 receptor antagonist, CS-866, on the PKC translocation, MAP kinase activity and cardiac hypertrophy in SNx rats. The left ventricle/body weight ratios were significantly larger in SNx rats than in sham rats at 1, 2, and 4 weeks after surgery. The translocation of PKCalpha and epsilon isoforms to membranous fraction was observed in SNx rat hearts at 1, 2, and 4 weeks after surgery. Activation of extracellular signal regulated kinase (ERK) 1/2, but not p38 MAP kinase and c-Jun N-terminal kinase (JNK), was observed at 1 and 2 weeks after surgery. Angiotensin II receptor blockade with CS-866 (1 mg kg-1 day-1) prevented cardiac hypertrophy, PKC translocation and ERK1/2 activation in SNx rats without significant changes in blood pressure. These data suggest that PKC and ERK1/2 are activated by an angiotensin II receptor-mediated pathway and might play an important role in the progression of cardiac hypertrophy in renal failure.

Clinical and simulator wear study of alumina ceramic THR to 17 years and beyond

Three THAs with cementless monolithic alumina ceramic sockets and cementless Co-alloy stems were retrieved because of aseptic loosening after 17 and 24 years. At revision heads and cups were marked for orientation. Maps were drawn of wear patterns with the use of light microscopy and surveyed by SEM. In a simulator experiment 28-mm-diameter alumina heads and liners were used. The cups were mounted inverted in a hip simulator and run with calf serum as the lubricant. The hip loads were 2 kN maximum and a 1-Hz frequency for 20 million cycles. Wear severity was classified into five grades. In retrieved implants, SEM analysis showed that the main wear zones (MWZ) had Grade 4 wear. The peripheral wear zones (PWZ) showed grain pull-out regions (Grade 5 wear). These corresponded to neck-socket impingement and head-acetabular cup separation. Gray was due to transferred CoCr particles from the stem. In the simulator study, the MWZ had only localized areas of grain pull out surrounded by polished surface regions (Grade 4 wear) at 20 million cycles; stripe wear was not seen. The alumina ceramic bearings proved excellent up to 22 years in simulator studies and clinical studies. However, microseparation kinematics would be necessary in the simulator to duplicate the more peripheral wear zones.

Intermolecular hydrophosphination of alkynes and related carbon[bond]carbon multiple bonds catalyzed by organoytterbiums

Intermolecular hydrophosphination of alkynes with diphenylphosphine is catalyzed by a Yb[bond]imine complex, [Yb(eta(2)-Ph(2)CNPh)(hmpa)(3)], to give alkenylphosphines and phosphine oxides after oxidative workup in good yields under mild conditions. This reaction is also applicable to various carbon[bond]carbon multiple bonds such as conjugated diynes and dienes, allenes, and styrene derivatives. Regio- and stereoselectivity and the scope and limitation of the present reaction clearly differ from those of the corresponding radical reaction. Instead, the reaction takes place through insertion of alkynes to a Yb[bond]PPh(2) species, followed by protonation. In fact, the Yb[bond]phosphido complex, [Yb(PPh(2))(2)(hmpa)(3)], is obtained from the imine complex and phosphine, which exhibits similar catalyst activity for the hydrophosphination. The empirical rate law is nu = k[catalyst](2) [alkyne](1)[phosphine](0) at least under the standard conditions.