Tem Specimen Preparation of Tial Alloy Powders Produced by Plasma Rotating Electrode Process

TEM specimens of PREPed Ti -48 at.% Al powders can be prepared reproducibly in a straight-forward manner. There are two kinds of powders with respect to surface and crosssectional morphologies. One is with an Widmanstitten-like structure and or a surface relief of martensitic phase and the other is with a dendritic structure. The primary phase during solidification and relative cooling rate in both the powders are discussed by comparing the macroscopic and microscopic features.

Two cases of variceal haemorrhage during living-donor liver transplantation

Some patients with cirrhosis experience rupture of venous varices before operation, and liver transplantation is a therapy of last resort for these patients. However, we have experienced two cases of intraoperative rupture in whom no abnormalities of the venous varices were seen on endoscopy before operation. One patient with ruptured gastrointestinal varices was treated by direct surgical ligation and the other with ruptured oesophageal gastric varices, spontaneously recovered with a Sengstaken-Blakemore tube. These cases suggest that acute variceal haemorrhage should always be considered as a possibility during living-donor liver transplantation in patients with a history of upper gastrointestinal bleeding. Careful observation of the nasogastic tube is important during clamping of the hepatic portal vein.

Creep deformation in a 3mol% Y2O3-Stabilized Tetragonal Zirconia

The high temperature deformation behavior of a 3mol% yttria-stabilized tetragonal zirconia (3Y-TZP) is examined. The analysis of creep strain rate, which was monitored directly with an optical extensometer and corrected for the current grain size, reveals a sigmoidal feature in the true stress-creep rate relationship. At lower stresses, a stress exponent n of ∼1.6 incorporated with a grain size exponent of 2.0 suggests the intervention of a lattice diffusion creep mechanism. For higher stresses where n ∼2.7, evidence of intragranular dislocation activities suggests that dislocations may play an important role in the accommodation process for grain boundary sliding in 3Y-TZP.

Blood flow changes caused by distal filter protection and catheter aspiration in the internal carotid artery during carotid stenting: evaluation using carotid Doppler sonography

BACKGROUND AND PURPOSE

If blood flow in the ICA is reduced by the use of a distal filter during CAS, flow stagnation proximal to the filter occurs and this increases the probability of floating debris. The floating debris that remains after filter retrieval may cause cerebral embolism. However, if blood flow is increased by aspiration of blood from the ICA through an aspiration catheter, debris could be removed while the filter is still in place. The purpose of this study was to investigate blood flow changes in the ICA induced by filter use and aspiration.

MATERIAL AND METHODS

A filter-protection device (AngioGuard XP) was used during CAS in 13 consecutive patients with carotid stenosis. Blood flow velocity in the ICA was measured by carotid Doppler sonography during filter deployment, filter retrieval, and catheter aspiration.

RESULTS

Blood flow velocity significantly decreased with filter placement and significantly increased with filter retrieval in patients with normal angiographic flow (P < .05). Aspiration of a 20-mL blood sample from the proximal ICA column significantly increased the blood flow velocity (P < .05).

CONCLUSIONS

The blood flow changes in the ICA induced by the use of a distal filter may cause cerebral embolism in filter-protected CAS. A routine aspiration method can potentially reduce the amount of migrating debris during CAS, even in cases with angiographic normal flow.

Routine Use of Debris Aspiration Before Retrieval of Distal Filter Protection Devices in Carotid Arterial Stenting: Analysis of Captured Debris and Evaluation of Clinical Results

BACKGROUND:

Distal filter protection allows for continuous cerebral perfusion during carotid artery stenting (CAS), although a higher risk of debris migrating into the cerebral arteries compared with other protection systems has been reported.

OBJECTIVE:

To improve the extent of debris capture, we used routine aspiration of blood located proximal to the filter in the internal carotid artery blood column before retrieval of the filter device.

METHODS:

Of 71 CAS procedures with distal filter protection, routine aspiration was performed in 41 procedures. The size and number of debris particles in each aspirated blood sample were measured under a stereoscopic microscope in 30 consecutive procedures with routine aspiration. Occurrence of periprocedural neurological events was compared between 41 procedures with routine aspiration and the other 30 without routine aspiration.

RESULTS:

In the aspirated blood, debris particles ≥500 μm and ≥1000 μm in the longest diameter were observed in 30 (100%) and 28 (93.3%) procedures, respectively. The number of particles ≥1000 μm was significantly larger in the second through fourth blood aspirates vs the first aspirate (P &lt; .05). Occurrence of periprocedural neurological events was significantly less frequent in the routine aspiration group (0 of 41 procedures) than in the conventional method group (7 of 30 procedures) (P &lt; .05).

CONCLUSION:

The use of routine aspiration during CAS with distal filter protection possibly reduced periprocedural neurological events by increasing the proportion of debris captured. To improve the capture of debris particles, at least 4 repeated aspirations are advisable during each CAS procedure.

Age-related thermal habitat use by Pacific salmon Oncorhynchus spp

Age-related thermal habitat use by sockeye Oncorhynchus nerka, chum Oncorhynchus keta and pink Oncorhynchus gorbuscha salmon was examined using trawl data obtained in spring in the North Pacific Ocean. Thermal habitat use differed by species and age. Larger and older fishes inhabited cooler areas, whereas smaller and younger fishes inhabited warmer areas.

Small-amplitude dynamic force microscopy using a quartz cantilever with an optical interferometer

We propose dynamic force microscopy (DFM) that employs a quartz cantilever in combination with an interferometric deflection sensor. The high stiffness of the quartz cantilever allows DFM to be performed at oscillation amplitudes as small as 1 A. DFM topographic images can be obtained for a Si(111)-(7 x 7) surface even when a blunt tip is used at room temperature. The low-noise interferometer with a deflection noise floor of n = 15 fm Hz(-1/2) exhibits a high force sensitivity in force spectroscopy. By subtracting the huge van der Waals force contribution, we obtain a short-range force curve that is in good agreement with the theoretical curve of the covalent bonding force. Simultaneous measurement of the tunneling current during DFM imaging is also demonstrated.

Enhanced initial bone regeneration with inorganic polyphosphate-adsorbed hydroxyapatite

Inorganic polyphosphate (poly(P)) can promote binding between fibroblast growth factors and their receptors and enhance osteoblastic cell differentiation and calcification. This study evaluated the possibilities for poly(P) adsorbed onto interconnected porous calcium hydroxyapatite (IP-CHA) as a new bone regeneration material. Prepared 1%, 5%, 25% and 50% poly(P)/IP-CHA composites showed the elution peak of poly(P) between 15 and 20 min, respectively, with the highest value from 50% poly(P)/IP-CHA in vitro. Histologically, at 1 week of placement into the femur of rabbits, granulation tissue had penetrated into the pores in all composites and IP-CHA as a control. In contrast, at 2 weeks of placement, newly formed lamellar bone was found in all groups, although a higher amount of bone regeneration was obviously formed in the 25% and 50% poly(P)/IP-CHA with a significantly higher value of bone regeneration ratio of 50% poly(P)/IP-CHA. These results indicate that 25% and 50% poly(P)/IP-CHA composites may enhance initial bone regeneration.

Change in cortical vein appearance on susceptibility-weighted MR imaging before and after carotid artery stenting

OBJECTIVES

Susceptibility-weighted (SW) magnetic resonance (MR) imaging is a sensitive test to detect intravenous deoxygenated blood. On SW images, dilated appearing draining veins in tissue with perfusion impairment occur due to an increase in intravenous deoxyhemoglobin levels, and could indicate poor perfusion areas in which there is an elevated oxygen extraction fraction. In this study, patients with possible chronic ischemia caused by internal carotid artery stenosis underwent carotid artery stenting (CAS). Changes in cortical vein diameters were evaluated before and after CAS using SW imaging.

METHODS

Twenty-two patients with 25 lesions underwent 3 T SW imaging before and after CAS. The diameters of cortical veins were measured on SW images. Blood flow reduction and cerebrovascular reserve were examined before CAS using a single-photon emission computed tomography (SPECT) study, including an acetazolamide stress test.

RESULTS

Two of six patients with both decreased blood flow and reduced cerebrovascular reserve on SPECT showed significantly increased cortical vein diameters on pre-CAS SW images (P<0.05). After CAS, these same two patients demonstrated a significant decrease in their cortical vein diameters (P<0.05).

DISCUSSION

The present study demonstrates that dilated cortical veins as seen on SW imaging may reflect areas of altered oxygen extraction fraction due to chronic ischemia in patients with carotid artery stenosis, and that cortical venous dilatation is reversed after successful CAS. In the future, estimations of the cortical vein diameters on SW imaging may help to qualitatively evaluate areas of poor perfusion in chronic ischemia.

Deposits on the intraluminal surface and bacterial growth in central venous catheters

Central venous catheter (CVC) tip and blood cultures are generally used to diagnose a catheter-related infection. Such methodology does not confirm the presence of bacterial colonisation on parts of CVCs other than the CVC tip. In order to assess the extent of bacterial colonisation, 10 catheters were examined in detail from patients admitted to intensive care unit. Swabs from the lumen at several sites (hub, indwelling and non-indwelling) were cultured and the intraluminal surface of the device subjected to scanning electron microscopy (SEM). Bacteria were detected on five out of 10 catheters (50%), and bacterial contamination of CVCs was common in the hub area of the device. Deposits (crystallisation) that differed from bacterial colonisation or biofilm were observed on the intraluminal surface of used CVCs. SEM showed bacteria firmly anchored to the deposits. Experimental flow studies demonstrated that deposits were more likely to appear after exposure to solutions such as total parenteral nutrition rather than distilled water. These deposits facilitated bacterial colonisation 30 times more than CVCs free from deposits.

Long-term follow up of patients with good outcome after intra-arterial thrombolysis for major arterial occlusion in the carotid territory: clinical and magnetic resonance imaging evaluation

Long-term clinical symptoms, including extrapyramidal signs, and magnetic resonance (MR) imaging studies were retrospectively analyzed in 21 patients with good outcome (modified Rankin scale scores 0-2) after successful recanalization of occluded major arteries by intra-arterial thrombolysis with mechanical disruption. Changes in high intensity areas (HIAs) and cerebral atrophy in the ischemic hemisphere were evaluated on follow-up fluid-attenuated inversion recovery MR images. Extrapyramidal signs, short-stepped gait and/or masked face, were observed in 12 of 21 patients during the follow-up period (11 to 68 months, mean 42 months). Enlargement of HIA was demonstrated in 10 of 18 patients undergoing follow-up MR imaging. Cerebral atrophy in the ischemic hemisphere was revealed on the follow-up MR images in all 18 patients. In nine patients with small infarctions, 20 ml or less on computed tomography scans, cerebral atrophy progressed more rapidly in four patients with extrapyramidal signs compared to the other five patients without extrapyramidal signs (p < 0.05). More than half of the patients with good outcome showed extrapyramidal signs. Extrapyramidal signs in patients with small infarction may indicate rapid progression of cerebral atrophy. The occurrence of extrapyramidal signs might be related to delayed neuronal death in atrophic areas.

Random number generation evaluation in patients with systemic lupus erythematosus indicates a heterogeneous nature of central nervous system vulnerability

OBJECTIVE

To evaluate the vulnerability of the central nervous system (CNS) in patients with systemic lupus erythematosus (SLE).

METHODS

Forty-eight patients with SLE, 58 with schizophrenia in remission and 39 healthy controls were enrolled in the study. Patients vocally generated 100 numbers in a random fashion, using numbers 0 to 9, and were evaluated with seriality scores. Patients with SLE were subgrouped according to differences in the presence of Raynaud's phenomenon, anti-phospholipid antibody, lupus activity, and a history of neuropsychiatric (NP) lupus, and these patients were also evaluated by comparison with their counterparts.

RESULTS

In general, patients with SLE showed lower seriality scores than patients with schizophrenia, and higher seriality scores than normal controls. The scores of the patients with a history of NP lupus matched those with schizophrenia, and the scores of never having NP lupus matched those of the healthy controls.

CONCLUSIONS

CNS vulnerability may be prolonged in patients who have a history of NP lupus even when they appear to be in normal NP status. The damage in random number generation (RNG) observed in patients with a history of NP lupus seemed equal to that found in those with schizophrenia, whereas those patients never having NP lupus appeared to be equal to the controls. The current study suggests a heterogeneous nature of SLE and prolonged damage, especially in CNS vulnerability, when evaluating with RNG.

Effect of combined application of bFGF and inorganic polyphosphate on bioactivities of osteoblasts and initial bone regeneration

Basic fibroblast growth factor (bFGF) and inorganic polyphosphate (poly(P)) have been recognized as therapeutic agents that enhance bone regeneration. It has also been shown that poly(P) may enhance the mitogenic activity of bFGF. The purpose of this study is to evaluate the combined effect of bFGF and poly(P) on bioactivities of osteoblasts and initial bone regeneration in vitro and in vivo. MC3T3-E1 cells were treated with bFGF, poly(P) or bFGF+poly(P), then subjected to cell proliferation assay, alkaline phosphatase (ALP) activity measurement, quantitative real-time reverse transcription-polymerase chain reaction and Alizarin S Red staining. In an in vivo study, bFGF-, poly(P)- and bFGF+poly(P)-modified interconnected porous hydroxyapatite (IPHA) complexes were fabricated, and placed into the femurs of rabbits to evaluate new bone formation histologically and histomorphometrically. The highest enhancement of cell proliferation were observed in those treated with bFGF+poly(P) on days 5 and 7. Cells treated with bFGF+poly(P) also exhibited increased ALP activity on days 5 and 10, up-regulated mRNA levels of osteocalcin and osteopontin, and enhanced calcification when compared to the non-treated cells. In vivo, the highest bone formation ratio was observed in bFGF+poly(P)-modified IPHA complexes. This study indicated that co-application of bFGF and poly(P) may provide enhanced bone formation by modulating cell proliferation and the mineralization process. It is anticipated that a combined application of bFGF and poly(P) can provide a novel method for bone regeneration in clinical use.

Serological study of dengue virus infection in Terai region, Nepal

A cross-sectional study was conducted to determine dengue virus IgM-positive rate in Terai region, Nepal from August to December 2007. Serum samples were collected from 183 symptomatic cases. The samples were examined for dengue virus specific IgM using particle agglutination test. Of 183 serum samples, 55 (30.0%) had positive for dengue IgM antibody. The positive rate was highest (50.0%) in Biratnagar, and lowest (19.6%) in Chitwan male to female ratio was 2:1 in IgM-positive populations. IgM-positive rate was 29.0% at ages 21-30, 25.4% at ages 11-20 and 23.6% at ages 0-10, but 10.9% at ages 31-40, and ages over 40. There was not significant association between occupation of the patients and positive rate among farmer, labour, service, business and student.

Latitudinal variation in egg size and number in anadromous masu salmon Oncorhynchus masou

Latitudinal variation in egg size and number in anadromous masu salmon Oncorhynchus masou was examined. Relatively greater variation in egg size occurred among rivers than among females within rivers or within females. Egg size was generally greater and egg number generally lower at more northerly latitudes.

Multipulse operation and optical detection of nuclear spin coherence in a GaAs/AlGaAs quantum well

We demonstrate manipulation of nuclear spin coherence in a GaAs/AlGaAs quantum well by optically detected nuclear magnetic resonance (NMR). A phase shift of the Larmor precession of photoexcited electron spins is detected to read out the hyperfine-coupled nuclear spin polarization. Multipulse NMR sequences are generated to control the population and examine the phase coherence in quadrupolar-split spin-3/2 75As nuclei. The phase coherence among the multilevel nuclear spin states is addressed by application of pulse sequences that are used in quantum gate operations.

Hyperglycemia and the outcome of pediatric cardiac surgery patients requiring peritoneal dialysis

OBJECTIVE

To study the nature of the association between glycemia and ICU mortality in pediatric cardiac surgery patients treated with peritoneal dialysis (PD).

MATERIALS AND METHODS

Retrospective observational study in the ICU of a tertiary hospital involving forty pediatric cardiac surgery patients treated with PD. We selected patients requiring PD, extracted glucose measurements and nutritional intake data during ICU stay and calculated mean and maximum blood glucose values i) during ICU stay; ii) during dependence on PD; and iii) during independence from PD. We statistically assessed the relationship between glycemia-related variables and ICU mortality.

MEASUREMENTS AND RESULTS

Twenty-two patients treated with PD died (mortality 55%). In the PD cohort, 9725 blood glucose measurements were performed (every 3.3 hours on average). The mean glycemia during dependence on PD was significantly higher in non-survivors than survivors (p<0.0001), but not during independence from PD (p=0.49). The area under the receiver operator characteristic curve for the mean glycemia during dependence on PD was significantly greater than that obtained during independence from PD. Even after adjustment for severity of illness using multivariate logistic analysis, the mean glycemia and calorie intake during PD were significant and independent predictors of ICU mortality.

CONCLUSIONS

A higher mean blood glucose concentration during PD, but not during PD-free periods was associated with greater ICU mortality. Mean glycemia and calorie intake during PD were significant and independent predictors of ICU mortality.