Effects of the Pt Shell Thickness on the Oxygen Reduction Reaction on a Well-Defined Pd@Pt Core-Shell Model Surface.

The effect of the Pt shell thickness on the oxygen reduction reaction (ORR) of a Pd@Pt core-shell catalyst was studied using surface science technics and computational approaches. We found Pt shells on Pd rods to be negatively charged because of charge transfer from the Pd substrate when the shell thicknesses were 0.5 or 1 monolayer (ML). The activities of the ORR of the model surface with a Pt shell of 0.5 or 1 ML were similar and more than twice the activities of a Pt/C or Pt rod. The relationship between the ORR activity and the thickness of the Pt shell was the exact opposite of the relationship between the Pt binding energy and the Pt shell thickness. The indication was that more negatively charged Pt had higher ORR activity. Density functional theory calculations confirmed that a single layer of Pt atoms located on Pd was negatively charged compared to pure Pt and resulted in a lower barrier to the rate-limiting step of the ORR.

Preparation and characterization of microporous layers on titanium by anodization in sulfuric acid with and without hydrogen charging.

The formation of microporous oxide layers on titanium (Ti) by anodization in sulfuric acid (H2SO4) solution and the influence of prior hydrogen charging on their properties are examined using electrochemical techniques, scanning electron microscopy, grazing incident X-ray diffraction, and X-ray photoelectron spectroscopy. When Ti is anodized in 1 M aqueous H2SO4 solution at a high direct current (DC) potential (>150 V) for 1 min, a porous surface layer develops, and the process takes place with spark-discharge. Under these conditions, oxygen evolution at the Ti electrode proceeds vigorously and concurrently with the formation of anodic oxide. The oxygen gas layer adjacent to the Ti surface acts as an insulator and triggers spark-discharge; the latter stimulates the development of pores. In the absence of spark-discharge, the oxide layer has extended surface roughness but low porosity. A porous oxide layer can be prepared by applying a lower DC voltage (130 V) and without spark-discharge, but Ti requires prior hydrogen charging by cathodic polarization in 1 M aqueous H2SO4 solution. Mott-Schottky measurements indicate that the oxide layers are n-type semiconductors and that the charge carrier density in the anodic oxide layer on the hydrogen-charged Ti is lower than in the case of untreated Ti. The hydrogen charging also affects the flat band potential of the anodic oxide layers on Ti by increasing its value. The reduced charge carrier density brought about by hydrogen charging decreases the oxide layer conductivity and creates favorable conditions for its electrical breakdown that stimulates the development of pores. The porous layer on the hydrogen-charged Ti consists of anatase and rutile phases of TiO2; it has the same chemical composition as the porous layer obtained on untreated Ti. X-ray photoelectron spectroscopy measurements show that prior hydrogen charging does not affect the thickness of anodic oxides on Ti. The porous oxide layer on Ti enables the growth of hydroxyapatite, thus revealing good bioactivity in simulated body fluids.

The effect of a prostaglandin E1 derivative on the symptoms and quality of life of patients with lumbar spinal stenosis.

BACKGROUND: Quality of life (QOL) is a concern for patients with lumbar spinal stenosis (LSS). In this study, QOL was examined using the 5-item EuroQol (EQ-5D). METHODS: QOL and activities of daily living (ADL) were surveyed for 91 patients who visited 18 medical institutions in our prefecture and were diagnosed with LSS-associated intermittent claudication. A second survey was performed after ≥6 weeks for 79 of the subjects to evaluate therapy with limaprost (an oral prostaglandin E1 derivative) or etodolac (an NSAID). Symptoms, maximum walking time, QOL, ADL items, and relationships among these variables were investigated for all 91 patients. Leg pain, leg numbness, and low back pain while walking were surveyed by use of VAS scores (0-100). RESULTS: Leg pain, leg numbness, and low back pain while walking (VAS ≥25) were present in 83.5, 62.6, and 54.9 % of the patients in the first survey, and approximately half of the patients had a maximum walking time <15 min. The mean EQ-5D utility value for QOL was 0.59 ± 0.12. This value was significantly associated with maximum walking time (p = 0.030) based on classification of patients into groups with walking times <7.5, 7.5-15, 15-30, and >30 min, showing that maximum walking time affected health-related QOL. Of the 79 patients who completed the second survey, 56 had taken limaprost and 23 (control group) had received etodolac. Limaprost improved possible walking time, reduced ADL interference, and significantly increased the EQ-5D utility score, whereas no significant changes occurred in the control group. Maximum walking time was prolonged by ≥10 min and the EQ-5D utility value was improved by ≥0.1 points in significantly more patients in the limaprost group than in the control group. CONCLUSION: According to the findings of this survey, at an average of 8 weeks after administration limaprost improved symptoms, QOL, and ADL in LSS patients whereas treatment with an NSAID reduced pain but did not have any other effects.

Sudden death due to undiagnosed intracranial hemangiopericytoma.

A previously healthy 9-year-old Japanese boy with a 4-day history of vomiting and headache died suddenly and unexpectedly. An external examination revealed no abnormalities other than foam around the mouth and nose. An internal examination revealed severe pulmonary edema and hemorrhagic hemangiopericytoma arising from the choroid plexus of the right lateral ventricle. The cause of death was thought to be neurogenic pulmonary edema caused by the rapid growth of a hemangiopericytoma, with intratumoral hemorrhage.

Carbon nanotubes with high bone-tissue compatibility and bone-formation acceleration effects.

Carbon nanotubes (CNTs) have been used in various fields as composites with other substances or alone to develop highly functional materials. CNTs hold great interest with respect to biomaterials, particularly those to be positioned in contact with bone such as prostheses for arthroplasty, plates or screws for fracture fixation, drug delivery systems, and scaffolding for bone regeneration. Accordingly, bone-tissue compatibility of CNTs and CNT influence on bone formation are important issues, but the effects of CNTs on bone have not been delineated. Here, it is found that multi-walled CNTs adjoining bone induce little local inflammatory reaction, show high bone-tissue compatibility, permit bone repair, become integrated into new bone, and accelerate bone formation stimulated by recombinant human bone morphogenetic protein-2 (rhBMP-2). This study provides an initial investigational basis for CNTs in biomaterials that are used adjacent to bone, including uses to promote bone regeneration. These findings should encourage development of clinical treatment modalities involving CNTs.

Computer-assisted screw insertion for cervical disorders in rheumatoid arthritis.

To reconstruct highly destructed unstable rheumatoid arthritis (RA) cervical lesions, the authors have been using C1/2 transarticular and cervical pedicle screw fixations. Pedicle screw fixation and C1/2 transarticular screw fixation are biomechanically superior to other fixation techniques for RA patients. However, due to severe spinal deformity and small anatomical size of the vertebra, including the lateral mass and pedicle, in the most RA cervical lesions, these screw fixation procedures are technically demanding and pose the potential risk of neurovascular injuries. The purpose of this study was to evaluate the accuracy and safety of cervical pedicle screw insertion to the deformed, fragile, and small RA spine lesions using computer-assisted image-guidance systems. A frameless, stereotactic image-guidance system that is CT-based, and optoelectronic was used for correct screw placement. A total of 21 patients (16 females, 5 males) with cervical disorders due to RA were surgically treated using the image-guidance system. Postoperative computerized tomography and plane X-ray was used to determine the accuracy of the screw placement. Neural and vascular complications associated with screw insertion and postoperative neural recovery were evaluated. Postoperative radiological evaluations revealed that only 1 (2.1%; C4) of 48 screws inserted into the cervical pedicle had perforated the vertebral artery canal more than 25% (critical breach). However, no neurovascular complications were observed. According to Ranawat's classification, 9 patients remained the same, and 12 patients showed improvement. Instrumentation failure, loss of reduction, or nonunion was not observed at the final follow-up (average 49.5 months; range 24-96 months). In this study, the authors demonstrated that image-guidance systems could be applied safely to the cervical lesions caused by RA. Image-guidance systems are useful tools in preoperative planning and in transarticular or transpedicular screw placement in the cervical spine of RA patients.

Posterior correction and fusion for severe cervical kyphosis in a patient with myotonic dystrophy: a case report.

STUDY DESIGN: A case report. OBJECTIVE: To report the first myotonic dystrophy case in which cervical kyphosis had been surgically corrected. SUMMARY OF BACKGROUND DATA: Myotonic dystrophy is an autosomal dominant disease that shows myotonia, progressive muscle atrophy, and other various symptoms. Instability of the neck is expected to cause disorders of the cervical spine; however, there are no detailed reports on deformity of cervical spine associated with this disease. METHODS: A 43-year-old man with cervical kyphosis due to myotonic dystrophy had undergone an occiput-T2 fusion with autogenous iliac bone using spinal instrumentation. RESULTS: The activity of daily life of the patient had improved markedly, and the good results continued to be preserved for 5 years. There were not any major perioperative complications. CONCLUSIONS: Surgical correction of cervical spine is not necessarily a contraindication for myotonic dystrophy.

Usefulness of post-mortem ophthalmological endoscopy during forensic autopsy: a case report.

Post-mortem intraocular findings in two autopsy cases with traumatic intracranial haemorrhage were obtained using an ophthalmological endoscope. The endoscopy results clearly revealed the presence of intraocular haemorrhages and papilledema caused by intracranial haemorrhage. Post-mortem ophthalmological endoscopy offers several benefits. First, post-mortem intraocular findings can be directly observed in corpses with post-mortem clouding of the cornea. Secondly, the endoscopy only requires a 0.9 mm incision in the sclera and does not require the removal of the eye from the corpse, a procedure that should be avoided for ethical and cosmetic reasons. Thus, post-mortem opthalmological endoscopy is a useful method for obtaining intraocular findings in autopsies.

A density functional study of NO adsorption and decomposition on Ni(211) and Pd(211) surfaces.

The adsorption and decomposition of NO have been investigated by using density functional theory method at the generalized gradient approximation level. We have performed calculations on adsorption energies and structures of NO on Ni(211) and Pd(211) surfaces with full-geometry optimization and compared them with the experimental data. The most favorite adsorption on both surfaces occurs at the bridge site parallel to step edge (sb), while the energy difference from the second favorite site of a threefold hollow site near step edge is less than 0.1 eV. Decomposition pathways have been investigated with transition state search. The decomposition pathway, where NO leans toward the step, is most probable for both surfaces. The overall activation energy for decomposition is 0.39 and 1.26 eV for Ni(211) and Pd(211), respectively. The present results clearly show that the NO molecules on Pd(211) are less activated than those on Ni(211). We have studied also reorganization of NO on Pd(211) at higher coverages up to 1/3 ML (monolayer) [three NO molecules in a (3 x 1) unit cell]. The site occupation is not in a sequential manner as the NO coverage is increased, and a reorganization of NO adsorbates occurs (the NO molecule at sb becomes tilting up at higher coverage), which can interpret the experimental data of Yates and co-workers very well.

Studies of NO adsorption on Pt(110)-(1 x 2) and (1 x 1) surfaces using density functional theory.

Adsorption of NO on Pt(110)-(1 x 2) and (1 x 1) surfaces has been investigated by density functional theory (DFT) method (periodic DMol(3)) with full geometry optimization and without symmetry restriction. Adsorption energies, structures, and N-O stretching vibrational frequencies of NO are studied by considering multiple possible adsorption sites and comparing with the experimental data. Adsorption is strongly dependent on both coverage and surface phase. The assignment of adsorption sites has been carried out with precise calculation of vibrational frequencies for NO on various sites. We clearly show the NO site switching on both of the surfaces as found in the experiments: at low coverages, bridge species is formed on the surface, and at high coverages, NO switches to atop sites.

Adsorption and reactions of NO on clean and CO-precovered Ir(111).

Adsorption and reactions of NO on clean and CO-precovered Ir(111) were investigated by means of X-ray photoelectron spectroscopy (XPS), high-resolution electron energy loss spectroscopy (HR-EELS), infrared reflection absorption spectroscopy (IRAS), and temperature-programmed desorption (TPD). Two NO adsorption states, indicative of fcc-hollow sites and atop sites, were present on the Ir(111) surface at saturation coverage. NO adsorbed on hollow sites dissociated to Na and Oa at temperatures above 283 K. The dissociated Na desorbed to form N2 by recombination of Na at 574 K and by a disproportionation reaction between atop-NO and Na at 471 K. Preadsorbed CO inhibited the adsorption of NO on atop sites, whereas adsorption on hollow sites was not affected by the coexistence of CO. The adsorbed CO reacted with dissociated Oa and desorbed as CO2 at 574 K.

[Vertebroplasty].

Vertebroplasty for pseudoartrosis of vertebral fracture using PMMA (polymethylmetacrylate) or CPC (calcium phosphate cement) is a new less invasive surgical method providing sufficient pain relief and correction of kyphosis.

DNA typing from cigarette butts.

We performed DNA typing for D1S80, HLADQA1, TH01 and PM using the butts of 100 cigarettes that were smoked by ten different individuals (ten cigarettes per individual). The results obtained from DNA typing for D1S80 agreed with the results obtained using bloodstains in 76 cigarette butt samples. Sixteen samples produced false results, showing the loss of the longer allelic hetero-band. When examined using agarose gel electrophoresis, high-molecular weight DNA was not observed in these samples. The same results were also observed for buccal swab samples and saliva stains obtained from the same individuals. In the remaining eight cigarette butt samples, PCR products were not detected. The results obtained from DNA typing for TH01, HLADQA1 and PM agreed with the results obtained using bloodstains in 90 samples. In the remaining ten samples of a specific kind of cigarette (Marlboro), the PCR products were not detected. The extracts from the ends of the Marlboro cigarettes were stained yellow. When the DNA extracted from Marlboro cigarette butts was treated with Microcon-100 (amicon) or SizeSep 400 Span Columns (Amersham Pharmacia Biotech), PCR products could be detected. When PCR amplification was performed after adding extracts from the ends of unsmoked Marlboro cigarettes to DNA extracted from bloodstains, PCR products could not be detected. The present data indicate that the degradation of high-molecular weight DNA and the inhibition of PCR by dyes of the cigarette end should be kept in mind when performing DNA typing using cigarette ends.

Quality and quantity of DNA in cadavers' serum.

We investigated the quality and quantity of DNA in sera obtained from 16 cadavers who were left at room temperature or placed in a refrigerator for cadavers within 3 days of their death. The causes of death were as follows: asphyxia, 4; hemorrhage, 4; fire, 3; cold, 1; subdural bleeding, 1; sepsis, 1; cerebral contusion, 1; and pulmonary thromboembolism, 1. When examined using agarose gel electrophoresis, the samples from the victims who died from sepsis and pulmonary thromboembolism exhibited smear patterns, while the other samples exhibited ladder patterns. The size of each band was an integer multiple of approximately 180 bp, considered to be characteristic of apoptosis. The DNA concentration in the cadavers' sera ranged from 3.0 to 258.9 ng/ml. DNA types (D1S80, HLADQA1, TH01, and PM) were determined for all the samples except for the sample from the victim who died from sepsis. The detected types were the same as those obtained from paired bloodstain samples, except for in the asphyxia victim. D1S80 typing of the serum sample from the asphyxia victim showed the loss of the longer allelic hetero-band. These results suggest that the quantity of DNA in serum from cadavers is sufficient for DNA typing, but that the degradation of DNA may proceed quickly, depending on the temperature of the area in which the cadaver is left as well as the pathological conditions that the victim had experienced.

Sequence polymorphism of mitochondrial DNA in Japanese individuals from Gifu Prefecture.

Sequence polymorphisms of the hypervariable region HV1 in mitochondrial DNA (mtDNA) were analyzed in a sample of 137 unrelated Japanese individuals living in Gifu Prefecture (central region of Japan) using polymerase chain reaction amplification and direct sequencing. Eighty-two different haplotypes resulting from 81 variable sites were found in the mtDNA HV1 region between positions 16061 and 16450. The most frequent haplotype (16223T, 16362C) was shared by ten individuals. The genetic diversity and the genetic identity were 0.985 and 0.022, respectively. The C-stretch region located around position 16189 was observed in 23.4% of this population sample. Sequence heteroplasmy at the position 16103 (A/G) was found in one individual.

Usefulness of postmortem ocular findings in forensic autopsy.

We report three autopsy cases in which the eyeballs were removed and examined macroscopically and microscopically after being cut using the alternate gross examination technique. The first case was a 67-year-old woman who was killed by ligature and manual strangulation. A postmortem opthalmological observation of the left eyeball revealed tiny hemorrhages and congestion in the pars plicae of the ciliary body. These changes were considered to arise by a mechanism similar to that by which facial hemorrhages arise during strangulation. The second case was a 54-year-old man who died from a cerebral contusion received during a traffic accident. A postmortem opthalmological observation of the eyeball using a surgical microscope revealed papilledema and retinal hemorrhages resulting from a rise in intracranial pressure. The third case was a 77-year-old woman who died from cardiac tamponade caused by a stab wound to the heart. A postmortem ophthalmological examination revealed that she had undergone cataract surgery and an intraocular lens implantation. However, her relatives did not know when and where she had received the surgery. An intraocular lens was removed and its material and shape was examined. Based on an examination of the lens, we were able to locate the hospital where she had received the surgery 4 years earlier. This suggests that postmortem opthalmological observations may be useful for forensic pathology and personal identification.

Myocardial damage by resuscitation methods.

Medico-legal autopsy cases were reviewed to detect myocardial changes induced by resuscitation methods. Myofibrillar degeneration (MFD) induced by resuscitation methods was classified into two types according to Luxol fast blue staining: contraction band (CB) and diffuse staining (DS). In the cases in which cardiopulmonary resuscitation had been performed, myocytes showing CB or DS formed small foci and were distributed in the papillary muscles, septum, and inner to middle layers of the myocardium. MFD induced by vasopressors was characterized by solitary distribution of degenerating myocytes that mainly showed DS and sometimes CB. When direct current countershocks had been performed, focal MFD in the subepicardial zone appeared to be a characteristic feature.

Elder abuse and neglect: social problems revealed from 15 autopsy cases.

This study examined the elder abuse cases that occurred in Gifu Prefecture, Japan between 1990 and 2000. We conducted a retrospective study of all the cases in which the victim was 65 years or older and autopsied in the Department of Legal Medicine, Gifu University School of Medicine. Fifteen victims were classified as elder abuse victims: five men and ten women. The victims ranged in age from 66 to 87 years (mean age, 74.5 years). The types of abuse were as follows: physical abuse, 13 cases; emotional abuse, five cases; neglect, four cases; and financial abuse, three cases. In eight cases, the victims were subjected to two or more types of abuse. The cause of death of the victims varied with the type of abuse. In the physical abuse cases, subdural hemorrhage was the most common cause, followed by other violence-related deaths and hypothermia. In the neglect cases, the victims died of either starvation or suffocation after the aspiration of food into the airway. In the domestic abuse cases, one of the victim's sons was the most common perpetrator, and little or no income was considered to be a risk factor for perpetrators. In the neglect cases, dementia and difficulty in performing activities of daily living were considered to be risk factors for victims, in addition to living in social isolation.