Fatigue measurement system designed for a chalcogenide-based device using a homemade heater tip

A fatigue measurement system is designed using a homemade tungsten (W) heater tip. This system is composed of a pulse generator and an atomic force microscope with the W heater tip attached. Also included are a parameter analyzer and control devices. The entire measurement process is controlled by a designed program without communication errors. Additionally, a process to fabricate the sharp W heater tip that applies an electrical pulse and evaluates the electrical properties is introduced. The analysis of the tip, carried out by scanning electron microscopy and electron backscattering diffraction, shows that the tip has great thermomechanical stability. Using this fatigue measurement system, the resistance of the Ge(2)Sb(2)Te(5) (GST) cell was successfully measured as a function of the number of set/reset cycles. The specific area (both program area and failure area) was easily observed. It is expected that the expansion of GST is a source of information regarding the fatigue of a GST cell.

Characterization of interparticle forces in the packing of cohesive fine particles

We numerically investigate force structures in the packing of fine cohesive particles using the discrete element method. By changing the particle size and therefore the van der Waals force, the effect of cohesion on the normal contact force and the total normal force, which is the sum of the normal contact forces and the van der Waals forces, is analyzed. It is shown that, with decreasing particle size, the normal contact forces become more uniform and have a narrower and more symmetric distribution, while the distributions of the total normal forces widen. Spatial correlation between the interparticle forces exists for the packing of coarse noncohesive particles. As the particle size decreases, this correlation becomes weaker for the contact forces but stronger for the total normal forces. A comparison between the effective weight of particles and the internal force structure suggests that there are differences between the particle-particle and particle-wall forces. The bimodal distribution of the effective weight indicates that there may exist two phases in the packings when cohesion is present, governed by the compressive and tensile stresses.

Pore structure of the packing of fine particles

This paper presents a numerical study of the pore structure of fine particles. By means of granular dynamics simulation, packings of mono-sized particles ranging from 1 to 1000 microm are constructed. Our results show that packing density varies with particle size due to the effect of the cohesive van der Waals force. Pores and their connectivity are then analysed in terms of Delaunay tessellation. The geometries of the pores are represented by the size and shape of Delaunay cells and quantified as a function of packing density or particle size. It shows that the cell size decreases and the cell shape becomes more spherical with increasing packing density. A general correlation exists between the size and shape of cells: the larger the cell size relative to particle size, the more spherical the cell shape. This correlation, however, becomes weaker as packing density decreases. The connectivity between pores is represented by throat size and channel length. With decreasing packing density, the throat size increases and the channel length decreases. The pore scale information would be useful to understand and model the transport and mechanical properties of porous media.

Settling characteristics of problem algae in the water treatment process

The settling velocity or removal rates of problem algae in the water treatment process and their flocculants were measured with settling column (SETCOL) and fluorometric method. Our research who were centred on the algal density and shape affecting the settling. The settling velocities of large algae ranged from 0.1 cm/h to 2.6 cm/h, whereas those of small algae were below 1.0 cm/h. The settlings of algae in the stationary growth phase significantly increased and dead algae corresponded with the declining algae. The extent of deformation, which was expressed as the coefficient of form resistance of the algae had the great influences upon the settling. The most extreme deformed algae were needle-shaped ones like Synedra acus, which was known to be a problem in water treatment processes in Korea. Changes in the settling velocity of algae were correlated with algal volume and morphology rather than cell density.

Fabrication of nanostructures of polyethylene glycol for applications to protein adsorption and cell adhesion

A simple method was developed to fabricate polyethylene glycol (PEG) nanostructures using capillary lithography mediated by ultraviolet (UV) exposure. Acrylate-containing PEG monomers, such as PEG dimethacrylate (PEG-DMA, MW = 330), were photo-cross-linked under UV exposure to generate patterned structures. In comparison to unpatterned PEG films, hydrophobicity of PEG nanostructure modified surfaces was significantly enhanced. This could be attributed to trapped air in the nanostructures as supported by water contact angle measurements. Proteins (fibronectin, immunoglobulin, and albumin) and cells (fibroblasts and P19 EC cells) were examined on the modified surfaces to test for the level of protein adsorption and cell adhesion. It was found that proteins and cells preferred to adhere on nanostructured PEG surfaces in comparison to unpatterned PEG films; however, this level of adhesion was significantly lower than that of glass controls. These results suggest that capillary lithography can be used to fabricate PEG nanostructures capable of modifying protein and cell adhesive properties of surfaces.

A prospective, randomized trial of endoscopic band ligation versus endoscopic hemoclip placement for bleeding gastric Dieulafoy's lesions

BACKGROUND AND STUDY AIMS

Dieulafoy's lesion is a rare cause of massive gastrointestinal hemorrhage, most commonly in the proximal stomach. Mechanical endoscopic methods have recently become the standard therapeutic approach. However, there have been few studies comparing the efficacy of different mechanical endoscopic methods in treating gastric Dieulafoy's lesions. This study was therefore carried out to compare the hemostatic efficacy and safety of endoscopic band ligation (EBL) and endoscopic hemoclip placement (EHP) in the treatment of bleeding gastric Dieulafoy's lesions.

PATIENTS AND METHODS

Between January 2002 and October 2003, 26 consecutive patients with bleeding gastric Dieulafoy's lesions were prospectively enrolled and were randomly assigned to undergo EBL (13 patients) or EHP (13 patients). Demographic characteristics, endoscopic variables, and outcome parameters, including rates of hemostasis and recurrent bleeding, were analyzed.

RESULTS

One O-ring was applied in each case in the EBL group, and the median number of hemoclips applied was one (range one to four) in the EHP group. There were no significant differences between the groups with regard to age, sex, presence of shock, initial hemoglobin level, coagulopathy, concurrent diseases, location of the lesion, type of bleeding stigmata, blood transfusion requirements, or hospitalization periods. Primary hemostasis was achieved in all 26 patients. There was one case of recurrent bleeding in each group; secondary hemostasis was achieved with EBL in one of these patients and by endoscopic epinephrine injection in the other. There were no second episodes of recurrent bleeding, no procedure-related complications, no cases in which surgery was needed, and no bleeding-related deaths in either group.

CONCLUSIONS

In this small study, no differences were detected in the efficacy or the safety of EBL vs. EHP in the management of bleeding gastric Dieulafoy's lesions.

Observation of large CP violation and evidence for direct CP violation in B0-->pi(+)pi(-) decays

We report the first observation of CP violation in B0-->pi(+)pi(-) decays based on 152x10(6) gamma (4S)-->BB decays collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We reconstruct a B0-->pi(+)pi(-) CP eigenstate and identify the flavor of the accompanying B meson from its decay products. From the distribution of the time intervals between the two B meson decay points, we obtain A(pipi)=+0.58+/-0.15(stat)+/-0.07(syst) and S(pipi)=-1.00+/-0.21(stat)+/-0.07(syst). We rule out the CP-conserving case, A(pipi)=S(pipi)=0, at a level of 5.2 standard deviations. We also find evidence for direct CP violation with a significance at or greater than 3.2 standard deviations for any S(pipi) value.

Endoscopic band ligation for control of acute peptic ulcer bleeding

BACKGROUND AND STUDY AIMS

The use of endoscopic band ligation (EBL) is being extended to treat various causes of upper and lower gastrointestinal bleeding. The aim of this study was to evaluate the usefulness of EBL for control of acute peptic ulcer bleeding and to define the lesions that are most suitable for this technique.

PATIENTS AND METHODS

19 patients with major stigmata of acute peptic ulcer bleeding were treated using EBL; 11 patients had active bleeding and eight patients had a nonbleeding visible vessel.

RESULTS

The site of acute peptic ulcer bleeding was the stomach in 12 patients, the duodenum in four patients, and Billroth II anastomosis in three. Initial hemostasis was achieved in 19 patients (100 %) in a single session. There were no rebleeding episodes in any of the patients, and there was no bleeding-related or procedure-related death. During long-term outpatient follow-up, bleeding did not recur.

CONCLUSIONS

EBL is an effective and safe endoscopic treatment for small-sized nonfibrotic acute peptic ulcer bleeding. Larger studies in patients with acute peptic ulcer bleeding are needed to confirm these promising results.

The usefulness of endoscopic hemoclipping for bleeding Dieulafoy lesions

BACKGROUND AND STUDY AIMS

Dieulafoy lesion is a rare cause of massive gastrointestinal hemorrhage, most commonly from the proximal stomach. Surgery was regarded as the treatment of choice in the past, but recently endoscopic management has become the standard approach. However, the effectiveness of various endoscopic modalities in treating bleeding Dieulafoy lesion has been little studied. This study was therefore done to compare the hemostatic efficacy of endoscopic hemoclipping and epinephrine injection therapy.

PATIENTS AND METHODS

Between January 1998 and December 2001, a consecutive series of 32 patients with bleeding Dieulafoy lesion underwent endoscopic treatment. They were randomly treated either by endoscopic epinephrine injection therapy (n = 16) or by hemoclipping (n = 16). We compared mortality rate, primary hemostasis rate, and rebleeding rate between two groups.

RESULTS

There was no bleeding-related death in either group. There was no significant difference in primary hemostasis rates between the hemoclipping group (93.8 %) and epinephrine injection group (87.5 %, P = 1.00). There was a trend toward a lower rate of need for multiple endoscopic sessions to achieve permanent hemostasis in the hemoclipping group compared with the epinephrine injection group (6.3 % vs. 31.3 %, P = 0.086). Hemoclipping was significantly more effective in preventing recurrent bleeding than epinephrine injection therapy (0 % vs. 35.7 %, P < 0.05). With regard to lesion site, hemoclipping was significantly more effective in preventing recurrent bleeding of gastric body Dieulafoy lesion than epinephrine injection therapy (0 % vs. 50 %, P < 0.05).

CONCLUSIONS

Bleeding from Dieulafoy lesion was well controlled by therapeutic endoscopic procedures. Hemoclipping was more effective for Dieulafoy lesion than epinephrine injection therapy, with less need for subsequent endoscopy.

Internal hernia presenting as obstructive jaundice and acute pancreatitis

We report the first case of obstructive jaundice and acute pancreatitis caused by herniation of the small bowel through the foramen of Winslow in a 45-year-old man. Abdominal computed tomography (CT) and magnetic resonance imaging (MRI) revealed dilated small-bowel loops positioned in the gastrohepatic space, dilatation of the gallbladder and both intrahepatic bile ducts, and mild swelling of the pancreas. A small-bowel series revealed a cluster of small-bowel loops in the mid-upper abdomen, with displacement of the stomach to the left. At laparotomy, there was an internal herniation of jejunal loop through the defect of gastrocolic ligament into the lesser sac and finally passing through the foramen of Winslow. The common bile duct was compressed externally by the herniated bowel and the pancreas was mildly swollen. To the best of our knowledge, these complications of internal hernia have not been reported previously.

Mycorrhizal colonization and plant growth affected by aqueous extract of Artemisia princeps var. orientalis and two phenolic compounds

The effects of an aqueous extract of Artemisia princeps var. orientalis and two phenolic compounds on mycorrhizal colonization and plant growth have been investigated. Greenhouse studies showed that the inhibitory effect of the extract on mycorrhizal colonization and plant growth increased in proportion to the concentration of the extract. When the mycorrhizal test plants were treated with an increasing concentration of phenolic compounds, the mycorrhizal colonization in roots of the test plant and the plant growth were decreased. There were strong indications that mycorrhizal fungi mitigated the inhibitory influence of shoot extract of A. princeps var. orientalis and phenolic compounds.

Massive gastrointestinal bleeding caused by ectopic pancreas mimicking jejunal tumor

BACKGROUND

Ectopic pancreas is usually an incidental finding at surgery or autopsy and rarely produces clinical symptoms. But it is capable of producing symptoms, depending on its location, size and involvement of the overlying mucosa.

CASE REPORT

We report a case with massive gastrointestinal bleeding from ectopic pancreas mimicking jejunal tumor, confirmed by emergency operation. A 40-year-old male was admitted to Chonnam National University Hospital with a 2-day history of melena. A technetium-99m-labeled RBC scan showed massive radioactivity in loops of small bowel due to active bleeding. Superior mesenteric angiography revealed a hypervascular stained mass supplied by proximal jejunal branch. A computed tomographic scan of abdomen revealed an enhancing mass in the proximal jejunum. At emergency operation, bleeding from the center of the mass was found situated approximately 30 cm from the Treitz ligament. Segmental resection of the involved jejunum and end-to-end anastomosis were performed. Histologic examination of resected specimen revealed an ectopic pancreas.

CONCLUSION

So far, there have been no case reports of massive gastrointestinal bleeding from ectopic pancreas mimicking jejunal tumor as described in our case. In every patient in whom ectopic pancreas can definitely be seen to cause clinical symptoms including gastrointestinal bleeding, the lesion should be excised.

Korean population genetic data for eleven STR loci

Allele frequency and forensic parameters for eleven STR loci were surveyed in a random sample from the Korean population.

Effects of carnitine coingested caffeine on carnitine metabolism and endurance capacity in athletes

The purpose of this study was to examine whether caffeine (CAF), carnitine (CAR), or CAF+CAR mixture administration affects exercise endurance time via carnitine metabolism. Water (CON), CAF, CAR, or CAF+CAR mixture was administered to five male rugby athletes participating in this study by a randomized double-blind fashion who were made to ride a cycle ergometer for exercise. The CAF effect on exercise endurance time was small, but the CAR trial significantly increased the exercise endurance time compared with CON trial; a further CAF+CAR mixture trial had greater effects on the exercise endurance time than those of a CON, CAF, or CAR trial. A CAR or CAF+CAR mixed trial increased urinary nonesterified carnitine (NEC) and total carnitine (TCAR), but no changes were observed in acid-soluble acylcarnitine (ASAC) and acid-insoluble acylcarnitine (AIAC) excretion. A CAR or CAF+CAR mixed trial resulted in higher levels of plasma NEC, ASAC, and TCAR fractions than the CON and CAF trials did on exhaustion time. Total cholesterol, triglyceride, and free fatty acid in blood were significantly increased at exhaustion time, but they were not affected in the CAF or the CAR trial. These results suggest that carnitine ingestion could promote fat oxidation, resulting in higher endurance performance in athletes, and especially these ergogenic effects of carnitine coingested with caffeine may be greater than those of carnitine alone.

Observation of B --> J/psi K(1)(1270)

We report the first observation of the exclusive decay process B-->J/psi K(1)(1270) using a sample of 11.2M BB macro meson pairs collected in the Belle detector at the KEKB asymmetric energy e(+)e(-) collider. We measure branching fractions of B[B(0)-->J/psi K(0)(1)(1270)] = (1.30+/-0.34+/-0.32) x 10(-3) and B[B(+)-->J/psi K(+)(1)(1270)] = (1.80+/-0.34+/-0.39) x 10(-3), where the first error is statistical and the second is systematic. These modes constitute approximately 15% of the total number of B-->J/psi X decays. No evidence is seen for B-->J/psi K(1)(1400) and we set an upper limit for this branching fraction.

Y-chromosome multiplexes and their potential for the DNA profiling of Koreans

We have developed four multiplex genotyping systems (GeneKin Y-STR multiplexes) using silver staining with allelic ladders for ten Y-chromosome STR markers (DYS19, DYS385, DYS388, DYS389I/II, DYS390, DYS391, DYS392, DYS393 and DXYS156Y), with a view towards the application of rapid and simple genotyping assay methods for DNA profiling. The GeneKin Y-STR multiplexes developed have followed the published nomenclature and ISFG guidelines for STR analysis. Allele and haplotype frequencies at these Y-STRs loci were analysed by PCR amplification using the GeneKin Y-STR multiplexes, followed by denaturing polyacrylamide gel electrophoresis in 316 unrelated males in the Korean population. A total of 295 different haplotypes were found, 279 of them being unique. Gene diversity ranged from 0.4026 at DYS391 to 0.9606 at DYS385. The haplotype diversity value (which is the same as the discrimination index) calculated from all ten loci combined was 0.9995, which is informative. Our results revealed that a set of ten Y-STRs can discriminate between most of the male individuals in the Korean population (discrimination capacity: 93.35%). The Y-STR multiplexes thus provide useful information for forensic analysis and paternity tests and can also be of great benefit for providing information not normally available from autosomal DNA systems.

Observation of Cabibbo suppressed B --> D(*)K- decays at Belle

We report observations of the Cabibbo suppressed decays B-->D((*))K- using a 10.4 fb(-1) data sample accumulated at the Upsilon(4S) resonance with the Belle detector at the KEKB e(+)e(-) storage ring. We find that the ratios of Cabibbo suppressed to Cabibbo favored branching fractions are B(B--->D0K-)/B(B--->D0pi(-)) = 0.079+/-0.009+/-0.006, B(B(0)-->D+K-)/B(B(0)-->D+pi(-)) = 0.068+/-0.015+/-0.007, B(B--->D(*0)K-)/B(B--->D(*0)pi(-)) = 0.078+/-0.019+/-0.009, and B(B(0)-->D(*+)K-)/B(B(0)-->D(*+)pi(-)) = 0.074+/-0.015+/-0.006. These are the first observations of the B-->D+K-, D(*0)K-, and D(*+)K- decay processes.

Observation of large CP violation in the neutral B meson system

We present a measurement of the standard model CP violation parameter sin2 phi(1) based on a 29.1 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. One neutral B meson is fully reconstructed as a J/psi K(S), psi(2S)K(S), chi(c1)K(S), eta(c)K(S), J/psi K(L), or J/psi K(*0) decay and the flavor of the accompanying B meson is identified from its decay products. From the asymmetry in the distribution of the time intervals between the two B meson decay points, we determine sin2 phi(1) = 0.99+/-0.14(stat)+/-0.06(syst). We conclude that we have observed CP violation in the neutral B meson system.

Does every patient with ureteropelvic junction obstruction need voiding cystourethrography?

PURPOSE

Voiding cystourethrography is routinely recommended to detect vesicoureteral reflux in children with ureteropelvic junction obstruction. Vesicouretral reflux coexisting with primary ureteropelvic junction obstruction is usually of low grade and resolves spontaneously after pyeloplasty, whereas pseudo ureteropelvic junction obstruction and obstruction secondary to high grade reflux usually present with a dilated ureter that is easily detected on real-time ultrasonography. We assessed the role of voiding cystourethrography in children with ureteropelvic junction obstruction by retrospectively evaluating the incidence and natural history of coexisting vesicourethral reflux.

MATERIALS AND METHODS

We reviewed the records of 106 children younger than 15 years who underwent pyeloplasty for ureteropelvic junction obstruction at our hospital between January 1990 and December 1998. A patient who had initially undergone antireflux surgery later underwent pyeloplasty for newly developed secondary obstruction was not included in the analysis. The diagnosis of ureteropelvic junction obstruction was based on ultrasonography and diuretic renography. Preoperative voiding cystourethrography was performed in all patients to detect vesicourethral reflux. We categorized reflux as low grade if the ureters were not dilated and as high grade if the ureters were dilated and tortuous.

RESULTS

There were 89 boys and 17 girls who underwent 115 pyeloplasties, including 9 who underwent bilateral pyeloplasty. Mean patient age at surgery was 27.4 months (63 infants, 6 between 1 and 2 years old, and 37 older than 2 years). Of these 106 patients 85 had unilateral (left side 64, right side 21) and 21 had bilateral ureteropelvic junction obstruction. Vesicourethral reflux was documented in 19 ureters of 12 children. Of the 85 cases of unilateral ureteropelvic junction obstructions 10 had vesicourethral reflux, which was bilateral 6, ipsilateral in 2 and contralateral in 2. Of the 21 cases of bilateral obstructions 2 had reflux, which was bilateral in 1 and was unilateral in 1. Reflux was low grade reflux in 6 and high grade in 6 cases. All low grade reflux disappeared spontaneously at an average period of 4.2 months (range 2 to 10) after pyeloplasty. All 6 patients with high grade reflux subsequently underwent antireflux surgery because of breakthrough urinary tract infection in 2 and persistent in 4 at an average of 36 months (range 3 to 112) after pyeloplasty. All high grade reflux coexisting with ureteropelvic junction obstruction was easily detected on real-time ultrasonography.

CONCLUSIONS

Low grade reflux coexisting with ureteropelvic junction obstruction spontaneously disappeared after pyeloplasty, and all high grade reflux coexisting with obstruction was easily detected on ultrasonography using real-time mode. Therefore, we believe that indication for voiding cystourethrography in children with ureteropelvic junction obstruction should be limited to those with dilated ureters on ultrasonography.

A case of hemorrhagic gallbladder paraganglioma causing acute cholecystitis

Gallbladder paraganglioma is a very rare tumor and so far only a few cases have been reported. Most of these were asymptomatic and were found incidentally during operation. Recently, we experienced a gallbladder paraganglioma that gave rise to hemorrhage, which in turn caused acute cholecystitis. Our case involved a 45 year-old female patient complaining of an intermittent right upper abdominal pain. After a preoperative evaluation, cholecystectomy and lymphadenectomy were performed under the impression of gallbladder cancer with acute cholecystitis. Postoperative pathologic examination revealed a hemorrhagic gallbladder paraganglioma accompanied by acute cholecystitis. Immunohistochemical staining of the chief cells for neuron specific enolase, chromogranin and synaptophysin were positive. Sustentacular cells also stained positively for S100 protein.

Does every patient with ureteropelvic junction obstruction need voiding cystourethrography?

PURPOSE

Voiding cystourethrography is routinely recommended to detect vesicoureteral reflux in children with ureteropelvic junction obstruction. Vesicouretral reflux coexisting with primary ureteropelvic junction obstruction is usually of low grade and resolves spontaneously after pyeloplasty, whereas pseudo ureteropelvic junction obstruction and obstruction secondary to high grade reflux usually present with a dilated ureter that is easily detected on real-time ultrasonography. We assessed the role of voiding cystourethrography in children with ureteropelvic junction obstruction by retrospectively evaluating the incidence and natural history of coexisting vesicourethral reflux.

MATERIALS AND METHODS

We reviewed the records of 106 children younger than 15 years who underwent pyeloplasty for ureteropelvic junction obstruction at our hospital between January 1990 and December 1998. A patient who had initially undergone antireflux surgery later underwent pyeloplasty for newly developed secondary obstruction was not included in the analysis. The diagnosis of ureteropelvic junction obstruction was based on ultrasonography and diuretic renography. Preoperative voiding cystourethrography was performed in all patients to detect vesicourethral reflux. We categorized reflux as low grade if the ureters were not dilated and as high grade if the ureters were dilated and tortuous.

RESULTS

There were 89 boys and 17 girls who underwent 115 pyeloplasties, including 9 who underwent bilateral pyeloplasty. Mean patient age at surgery was 27.4 months (63 infants, 6 between 1 and 2 years old, and 37 older than 2 years). Of these 106 patients 85 had unilateral (left side 64, right side 21) and 21 had bilateral ureteropelvic junction obstruction. Vesicourethral reflux was documented in 19 ureters of 12 children. Of the 85 cases of unilateral ureteropelvic junction obstructions 10 had vesicourethral reflux, which was bilateral 6, ipsilateral in 2 and contralateral in 2. Of the 21 cases of bilateral obstructions 2 had reflux, which was bilateral in 1 and was unilateral in 1. Reflux was low grade reflux in 6 and high grade in 6 cases. All low grade reflux disappeared spontaneously at an average period of 4.2 months (range 2 to 10) after pyeloplasty. All 6 patients with high grade reflux subsequently underwent antireflux surgery because of breakthrough urinary tract infection in 2 and persistent in 4 at an average of 36 months (range 3 to 112) after pyeloplasty. All high grade reflux coexisting with ureteropelvic junction obstruction was easily detected on real-time ultrasonography.

CONCLUSIONS

Low grade reflux coexisting with ureteropelvic junction obstruction spontaneously disappeared after pyeloplasty, and all high grade reflux coexisting with obstruction was easily detected on ultrasonography using real-time mode. Therefore, we believe that indication for voiding cystourethrography in children with ureteropelvic junction obstruction should be limited to those with dilated ureters on ultrasonography.