Polarization switching dynamics governed by the thermodynamic nucleation process in ultrathin ferroelectric films

In most ferroelectrics, the domain nucleation barrier (U*) is thermally insurmountable; this is called "Landauer's paradox." However, we showed that, in ultrathin films, the large depolarization fields could lower U* to a level comparable to thermal energy (k(B)T), resulting in power-law decay of polarization. We empirically found a universal relation between the power-law decay exponent and U*/k(B)T. This relation will provide a practical but fundamental limit for capacitor-type ferroelectric devices, analogous to the superparamagnetic limit for magnetic memory devices.

Liver transplantation for hepatocellular carcinoma with bile duct thrombi

In a few cases of hepatocellular carcinoma (HCC), jaundice results from obstructive causes, including tumor invasion or thrombi in the bile duct. We have reported herein our experience with liver transplantation (OLT) for HCC cares showing bile duct thrombi (BDT). From September 1996 to August 2004, 140 adult patients underwent OLT for HCC at our center. Four patients (2.9%) who had OLT performed for HCC had BDT and were included in this study. The patients were all men of mean age 57.0 years. The initial total bilirubin levels were in the range of 2.0 to 30.5 mg/dL. The sizes of the tumors ranged from 2.0 cm to 3.0 cm in diameter, all were single lesions. The median follow-up period was 20.6 months (range: 17.6 to 28.1 months). The only case in which the BDT was identified intraoperatively died 20 months after OLT due to multiple intrahepatic recurrences. The other three patients were alive, showing no evidence of recurrence at the end of follow-up. Although a series of four is too small to reach any conclusion, we suggest that OLT may be a treatment option for HCC with BDT in selected cases.

Safety of donors with fatty liver in liver transplantation

Steatotic liver graft transplantation affect donor safety as well as recipient survival. We investigated safety of donors according to the extent of fatty change. We retrospectively reviewed donors who underwent right hepatectomy from September 1999 to April 2005, dividing them into three groups according to degree of macrovesicular fatty change upon intraoperative liver biopsy. Group 1 included patients with macrovesicular steatosis of 0 approximately 9%: group 2, 10 approximately 19% and group 3, at least 20%. Two hundred forty-five donors were enrolled with a male to female ratio of 2.02:1 and mean age of 31.8 years. There were 163 donors in group 1, 75 in group 2, and seven in group 3. There was no statistically significant difference in body mass index, operative time, blood loss, postoperative peak serum bilirubin, and aspartate transaminase levels among groups 1, 2, and 3. Overall complication rate, including reoperation, biliary stricture, wound infection, ileus, transfusion, bile leak and fluid collection were not different between the groups. Postoperative hospital stay was also not different. Peak alanine transaminase level was different between each group, and prothrombin time between group 1 and 3, but days until return to normal levels in all measured laboratory parameters were not different. Residual liver volume percent was significantly smaller among group 1 compared to others. In conclusion, fatty livers with less than 30% macrovesicular steatosis may be good donor candidates without significant complications as long as sufficient residual liver volume is left for the donor.

Results of transvenous embolization of cavernous dural arteriovenous fistula: a single-center experience with emphasis on complications and management

BACKGROUND AND PURPOSE

To describe the results of transvenous embolizations of cavernous dural arteriovenous fistua (cDAVF) with an emphasis on identifying the incidence, characteristics, and management strategies associated with the complications of transvenous embolization of cDAVFs.

METHODS

Fifty-six consecutive patients who were treated by transvenous embolization for cDAVFs were reviewed. The approach routes, angiographic results, complications, and clinical outcome were assessed.

RESULTS

Retrograde inferior petrosal sinus (n = 36), transfacial vein (n = 7), transcontralateral intercavernous sinus (n = 4), and direct superior ophthalmic vein (n = 3) approaches were used. Angiographic results showed complete occlusion (n = 29), nearly complete occlusion (n = 13), and incomplete occlusion (n = 14). Complications associated with the procedures were cranial nerve palsy (n = 6), venous perforation (n = 3), and brain stem congestion (n = 2). The cranial nerve signs resolved with conservative treatment. Venous perforations were managed by coil embolizations at the site of the tear with no significant neurologic sequelae. One case of brain stem congestion resulted in hemiplegia after conservative treatment. The other case showed venous congestion as a result of rerouting of the shunted flow after venous embolization that was successfully managed by covered stent deployment for occlusion of the residual feeders. Clinical follow-up data were available in 46 patients. Complete resolution or improvement of symptoms was seen in 42 patients (91%).

CONCLUSIONS

Cavernous DAVFs may be effectively treated by transvenous embolization. However, the procedure can be associated with various complications, some of which can potentially result in significant morbidity. Prompt diagnosis of the complications with appropriate management strategies is mandatory for a safe procedure.

Synthesis and antibacterial activities of new 1β-methylcarbapenems having aminopyrimidinylthioether moiety

The synthesis of new 1beta-methylcarbapenems 1a-d bearing aminopyrimidinylthioether moiety at C-5 position of pyrrolidine ring and their antibacterial activities are described. All the compounds exhibited potent antibacterial activity. Of these carbapenems, 1d showed the best combination of antibacterial activity and stability to dehydropeptidase-I (DHP-I).

Prognosis After Liver Transplantation Predicted by Preoperative MELD Score

The model for end-stage liver disease (MELD) has been an excellent predictor of 3-month mortality among cirrhotic patients awaiting orthotopic liver transplantation (OLT). The aim of this study was to evaluate whether the preoperative MELD score predicts short-term prognosis after OLT. We enrolled 98 adult liver transplant patients performed at our center from January 2001 to December 2002. In univariate analysis of risk factors for death within 3 and 6 months after liver transplantation, serum total bilirubin, creatinine, MELD score, hyponatremia with ascites, Child-Turcotte-Pugh (CTP) score were statistically significant parameters (P < .05). By logistic regression, none of the risk factors were subjected to multivariate analysis showed statistical significance. The odds ratios of the MELD score, hyponatremia with ascites, CTP score within 3 months were 0.997, 1.151, and 0.726 with 95% confidence intervals of [0.899, 1.105], [0.102, 12.959], and [0.389, 1.352], respectively. The odds ratio of MELD score, hyponatremia with ascites, CTP score within 6 months were 0.996, 0.914, and 0.764, with 95% confidence intervals of [0.901, 1.102], [0.089, 9.369], and [0.417, 1.401], respectively. Although MELD score has been a good predictor of short-term prognosis before OLT, MELD did not show an influence on the short-term prognosis after liver transplantation in this study.

Outcome of Patients With Recurrent Hepatocellular Carcinoma in Liver Transplantation

Liver transplantation (OLT) is the treatment of choice for patients with hepatic cirrhosis related hepatocellular carcinoma (HCC). Among 156 liver transplant patients for HCC from June 1996 to February 2005, 23 had recurrent HCC. To evaluate risk factors that affect early recurrence of HCC after OLT, we divided the 23 patients into two groups: early (< or =12 months) and late (>12 months) recurrences. Among them, 15 patients were dead and eight alive patients had been followed to 31 July 2005. The most common recurrence site was the grafted liver (n = 15), next was bone (n = 11), lung (n = 8), lymph node (n = 6), brain (n = 4), skin (n = 2), adrenal gland (n = 1). There were no significant differences between the two groups in age or tumor size, number of tumors, cell differentiation, alpha-feto protein levels, tumor staging, number of patients within Milan criteria, steroid pulse therapy, infectious diseases, and immunostaining of tumor. In our study, there were no risk factors that predict early tumor recurrence. We noticed that more patients in the early recurrence group were excluded by Milan criteria due to a more progressed tumor staging with higher mean levels of serum alpha-feto protein.

Outcomes of Hepatitis B Virus Recurrence After Liver Transplantation

The introduction of high doses of hepatitis B immune globulin (HBIG) and lamivudine for liver transplantation (OLT) prophylaxis has reduced the risk of hepatitis B recurrence and improved the survival of patients transplanted for hepatitis B virus (HBV)-related liver disease. But, posttransplant prophylaxis strategies to treat the recurrence of HBV have not yet been standardized. We analyzed 23 patients with HBV recurrence among 340 HBV-associated liver transplants performed from September 1996 to April 2004 (6.7%). Nine patients underwent deceased donor OLT and 14, living donor OLT. Mean follow-up was 37 months. Seroconversion after recurrence was observed in 6 of 23 patients (26%). Mean time to HBV recurrence tended to be shorter among the seroconversion (+) patients compared to seroconversion (-) patients (10 months vs 19.7 months; P = .062). Seroconversion rate after HBIG and lamivudine combination therapy for patients with HBV recurrence was 37.5% and time to seroconversion after HBV recurrence was 1.7 months. Seroconversion was best achieved when the pretransplant HBV DNA level was high and HBeAg was positive. Also, seroconversion rate was increased when HBV DNA level was low and the alanine transferase level high at the time of recurrence and when the time to recurrence after transplantation was short. Seroconversion after HBV recurrence, which was observed in 26%, may be increased in selected cases. Accordingly, aggressive treatment should be undertaken after HBV recurrence.

Dense-medium modifications to jet-induced hadron pair distributions in Au+Au collisions at sqrt s NN=200 GeV

Azimuthal correlations of jet-induced high-p(T) charged hadron pairs are studied at midrapidity in Au+Au collisions at sqrt[s(NN)]=200 GeV. The distribution of jet-associated partner hadrons (1.0<p(T)<2.5 GeV/c) per trigger hadron (2.5<p(T)<4.0 GeV/c) is found to vary with collision centrality, in both shape and yield, indicating a significant effect of the nuclear collision medium on the jet fragmentation process.

Azimuthal angle correlations for rapidity separated Hadron pairs in d+Au collisions at square root of sNN=200 GeV

Deuteron-gold (d+Au) collisions at the Relativistic Heavy Ion Collider provide ideal platforms for testing QCD theories in dense nuclear matter at high energy. In particular, models suggesting strong saturation effects for partons carrying small nucleon momentum fraction (x) predict modifications to jet production at forward rapidity (deuteron-going direction) in d+Au collisions. We report on two-particle azimuthal angle correlations between charged hadrons at forward/backward (deuteron/gold going direction) rapidity and charged hadrons at midrapidity in d+Au and p+p collisions at square root of sNN=200 GeV. Jet structures observed in the correlations are quantified in terms of the conditional yield and angular width of away-side partners. The kinematic region studied here samples partons in the gold nucleus with x~0.1 to ~0.01. Within this range, we find no x dependence of the jet structure in d+Au collisions.

Common suppression pattern of eta and pi0 mesons at high transverse momentum in Au + Au collisions at square root S(NN) = 200 GeV

Inclusive transverse momentum spectra of eta mesons have been measured within p(T) = 2-10 GeV/c at midrapidity by the PHENIX experiment in Au + Au collisions at square root S(NN) = 200 GeV. In central Au+Au the eta yields are significantly suppressed compared to peripheral Au + Au, d + Au, and p + p yields scaled by the corresponding number of nucleon-nucleon collisions. The magnitude, centrality, and p(T) dependence of the suppression is common, within errors, for eta and pi0. The ratio of eta to pi0 spectra at high p(T) amounts to 0.40 < R(eta/pi)0 < 0.48 for the three systems, in agreement with the world average measured in hadronic and nuclear reactions and, at large scaled momentum, in e+e- collisions.

Protective effect of agmatine on a reperfusion model after transient cerebral ischemia: Temporal evolution on perfusion MR imaging and histopathologic findings

BACKGROUND AND PURPOSE

The goal of thrombolytic therapy in patients with acute ischemic stroke is early recanalization, but this may result in delayed reperfusion injury. The purpose of this study was to evaluate the neuroprotective effect of agmatine in a transient ischemic cat model by using MR perfusion imaging and histopathologic analyses.

METHOD

One-hour temporary occlusion of the left middle cerebral artery of cats was performed in the control ischemia group (n = 10), and 100 mg/kg of agmatine was intravenously injected immediately after recanalization in the agmatine-treated group (n = 15). MR imaging was performed at 1, 24, and 48 hours after recanalization, and the perfusion patterns were investigated. Terminal-deoxynucleotidyl transferase mediated nick and end-labeling (TUNEL) and hematoxylin-eosin (H&E) stainings were performed at the corresponding sections.

RESULTS

In the control ischemia group, the number of TUNEL-positive cells was significantly increased in the areas with reperfusion hyperemia (P < .05). In the agmatine-treated group, no significant increase in the number of TUNEL-positive cells was noted in the areas of reperfusion hyperemia. The difference in the number of TUNEL-positive cells between the control ischemia and agmatine-treated group in the areas of reperfusion hyperemia was significant (P < .05). The total number of TUNEL-positive cells and the area of severe ischemic neuronal damage on H&E stain were also significantly attenuated in the agmatine-treated cats compared with the control ischemia cats (P < .05).

CONCLUSION

Our results suggest that agmatine has neuroprotective effects against reperfusion injury and ischemia.

PPARbeta/delta selectively induces differentiation and inhibits cell proliferation

Peroxisome proliferator-activated receptor (PPAR) beta-null mice exhibit exacerbated epithelial cell proliferation and enhanced sensitivity to skin carcinogenesis, suggesting that ligand activation of PPARbeta will inhibit keratinocyte proliferation. By using of a highly specific ligand (GW0742) and the PPARbeta-null mouse model, activation of PPARbeta was found to selectively induce keratinocyte terminal differentiation and inhibit keratinocyte proliferation. Additionally, GW0742 was found to be anti-inflammatory due to inhibition of myeloperoxidase activity, independent of PPARbeta. These data suggest that ligand activation of PPARbeta could be a novel approach to selectively induce differentiation and inhibit cell proliferation, thus representing a new molecular target for the treatment of skin disorders resulting from altered cell proliferation such as psoriasis and cancer.

The effects of Goami No. 2 rice, a natural fiber-rich rice, on body weight and lipid metabolism

OBJECTIVE

Increased intake of dietary fiber reduces the risk of obesity and type 2 diabetes. We assessed the effects of a fiber-rich diet on body weight, adipokine concentrations, and the metabolism of glucose and lipids in non-obese and obese subjects in Korea, where rice is the main source of dietary carbohydrates.

RESEARCH METHODS AND PROCEDURES

Eleven healthy, non-obese and 10 obese subjects completed two 4-week phases of individual isoenergetic food intake. During the control diet phase, subjects consumed standard rice; during the modified diet phase, subjects consumed equal proportions of fiber-rich Goami No. 2 rice and standard rice. We used a randomized, controlled, crossover study design with a washout period of 6 weeks between the two phases.

RESULTS

After the modified diet phase, body weight was significantly lower in both the non-obese and obese subjects (non-obese, 57.0 +/- 2.9 vs. 56.1 +/- 2.8 kg, p = 0.001; obese, 67.7 +/- 2.1 vs. 65.7 +/- 2.0 kg, p < 0.001 for before vs. after). The BMI was significantly lower in obese subjects (26.9 +/- 0.5 vs. 26.0 +/- 0.6 kg/m2, p < 0.001). The modified diet was associated with lower serum triacylglycerol (p < 0.01), total cholesterol (p < 0.01), low-density lipoprotein cholesterol (p < 0.05), and C-peptide (p < 0.05) concentrations in the obese subjects.

DISCUSSION

These results indicate that fiber-rich Goami No. 2 rice has beneficial effects and may be therapeutically useful for obese subjects.

Single electrons from heavy-flavor decays in collisions at

The invariant differential cross section for inclusive electron production in p+p collisions at [FORMULA: SEE TEXT] has been measured by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider over the transverse momentum range 0.4<or=pT<OR=5.0 GeV/c in the central rapidity region ([FORMULA: SEE TEXT]). The contribution to the inclusive electron spectrum from semileptonic decays of hadrons carrying heavy flavor, i.e., charm quarks or, at high , bottom quarks, is determined via three independent methods. The resulting electron spectrum from heavy-flavor decays is compared to recent leading and next-to-leading order perturbative QCD calculations. The total cross section of charm quark-antiquark pair production is determined to be [FORMULA: SEE TEXT].

Measurement of identified and inclusive photon second-harmonic parameter and implications for direct photon production in [FORMULA: SEE TEXT] Au+Au

The azimuthal distribution of identified pi0 and inclusive photons has been measured in [FORMULA: SEE TEXT] Au+Au collisions with the PHENIX experiment at the Relativistic Heavy-Ion Collider (RHIC). The second-harmonic parameter (nu2) was measured to describe the observed anisotropy of the azimuthal distribution. The measured inclusive photon is consistent with the value expected for the photons from hadron decay and is also consistent with the lack of direct photon signal over the measured pT range 1-6 GeV/c. An attempt is made to extract nu2 of direct photons.

Nuclear modification of electron spectra and implications for heavy quark energy loss in Au+Au collisions at [FORMULA: SEE TEXT]

The PHENIX experiment has measured midrapidity ([FORMULA: SEE TEXT]) transverse momentum spectra ([FORMULA: SEE TEXT]) of electrons as a function of centrality in Au+Au collisions at [FORMULA: SEE TEXT]. Contributions from photon conversions and from light hadron decays, mainly Dalitz decays of pi0 and eta mesons, were removed. The resulting nonphotonic electron spectra are primarily due to the semileptonic decays of hadrons carrying heavy quarks. Nuclear modification factors were determined by comparison to nonphotonic electrons in p+p collisions. A significant suppression of electrons at high pT is observed in central Au+Au collisions, indicating substantial energy loss of heavy quarks.

J/psi production and nuclear effects for d + Au and p + p collisions at square root of S(NN) = 200 GeV

J/psi production in d + Au and p + p collisions at square root of S(NN) = 200 GeV has been measured by the PHENIX experiment at rapidities -2.2 < y < +2.4. The cross sections and nuclear dependence of J/psi production versus rapidity, transverse momentum, and centrality are obtained and compared to lower energy p + A results and to theoretical models. The observed nuclear dependence in d + Au collisions is found to be modest, suggesting that the absorption in the final state is weak and the shadowing of the gluon distributions is small and consistent with Dokshitzer-Gribov-Lipatov-Altarelli-Parisi-based parametrizations that fit deep-inelastic scattering and Drell-Yan data at lower energies.

Association of PLXNA2 polymorphisms with vertebral fracture risk and bone mineral density in postmenopausal Korean population

INTRODUCTION

Plexin A2 (PLXNA2) is a receptor that recognizes secreted or membrane-bound semaphorin 3A, which is implicated in neural regulation of bone metabolism.

MATERIALS AND METHODS

In the present study, we identified 48 genetic polymorphisms in PLXNA2 by resequencing, and 10 single nucleotide polymorphisms (SNPs) were selected for further investigation into their potential involvement in osteoporosis in a postmenopausal population (n=560).

RESULTS

Two SNPs, +14G>A (Gln5Arg) and +183429C>T (Tyr1621Tyr), and Block1-ht2 were associated with risk of vertebral fracture (p=0.01-0.05), and three SNPs, +799G>A (Ala267Thr), +135391G>A, and +190531G>C, were associated with bone mineral density at various femur sites (p=0.003-0.03). Particularly, the minor allele of +14G>A was associated with a protective effect on vertebral fracture and higher lumbar bone mineral density, suggesting that +14G>A may be a useful marker for osteoporosis and its related fracture.

CONCLUSION

These results provide, for the first time, evidence supporting the association of PLXNA2 with osteoporosis in postmenopausal women.

Polarization relaxation induced by a depolarization field in ultrathin ferroelectric capacitors

Time-dependent polarization relaxation behavior induced by a depolarization field E(d) was investigated on high-quality ultrathin SrRuO3/BaTiO3/SrRuO3 capacitors. The E(d) values were determined experimentally from an applied external field to stop the net polarization relaxation. These values agree with those from the electrostatic calculations, demonstrating that a large E(d) inside the ultrathin ferroelectric layer could cause severe polarization relaxation. For numerous ferroelectric devices of capacitor configuration, this effect will set a stricter size limit than the critical thickness issue.

Measurement of transverse single-spin asymmetries for midrapidity production of neutral pions and charged hadrons in polarized p + p collisions at square root(s) = 200 GeV

Transverse single-spin asymmetries to probe the transverse-spin structure of the proton have been measured for neutral pions and nonidentified charged hadrons from polarized proton-proton collisions at midrapidity and square root(s) = 200 GeV. The data cover a transverse momentum (pT) range 1.0-5.0 GeV/c for neutral pions and 0.5-5.0 GeV/c for charged hadrons, at a Feynman-x value of approximately zero. The asymmetries seen in this previously unexplored kinematic region are consistent with zero within errors of a few percent. In addition, the inclusive charged hadron cross section at midrapidity from 0.5 < pT < 7.0 GeV/c is presented and compared to next-to-leading order perturbative QCD (pQCD) calculations. Successful description of the unpolarized cross section above approximately 2 GeV/c suggests that pQCD is applicable in the interpretation of the asymmetry results in the relevant kinematic range.

Depressive symptoms of type 2 diabetics treated with insulin compared to diabetics taking oral anti-diabetic drugs: a Korean study

OBJECTIVE

The purpose of this study was to examine the depressive symptoms of type 2 diabetic patients who were treated with insulin compared to those diabetics treated with oral anti-diabetic drugs in Korea.

METHODS

A total 204 outpatients with type 2 diabetes were invited to complete a questionnaire using the Beck depression inventory (BDI) to measure depressive symptoms. Age, gender, body mass index, serum lipid profile, and a social history including marital status, occupation and educational background were also assessed. The presence of diabetic complications was evaluated by examining the patients' medical records. Diabetic patients who were not treated with anti-diabetic drugs were excluded. All the study subjects were classified into two groups based on their mode of therapy: the oral drug group and insulin group. The insulin group included patients treated with insulin-oral drug combinations as well as those treated solely with insulin.

RESULTS

Overall, 32.4% of our diabetic subjects showed depressive symptoms with the criterion being a BDI score > or = 16. Compared to the oral drug group, the insulin group showed a significantly higher frequency of depressive symptoms (insulin group, 48.0%; oral drug group, 27.3%; p<0.01) and higher BDI scores (insulin group, 16.6+/-10.7; oral drug group, 12.6+/-8.7; p<0.01). Moreover, after an adjustment for social factors, the degree of hyperglycemia and the presence of diabetic complications, the insulin group showed a significantly higher frequency of depression (odds ratio 4.38, 95% CI 1.66-11.6, p=0.003), compared to the oral drug group.

CONCLUSIONS

The data showed that insulin treatment is related to the presence of depressive symptoms, and the importance of more careful psychological support of Korean insulin-treated type 2 diabetic patients is strongly suggested.

Perforating disorder caused by salt-water application and its experimental induction

BACKGROUND

Perforating disorders are uncommon diseases characterized by transepidermal elimination histopathologically and include reactive perforating collagenosis, elastosis perforans serpiginosa, Kyrle's disease and perforating folliculitis. In addition, perforating disorders can develop in patients with diabetes mellitus, renal failure and even by accidental exposure of calcium salts.

METHODS

We report two cases of perforating disorder caused by chemical burn with commercially available salt-water application for self-treatment of chronic dermatitis or pruritus.

RESULTS

The commercially used salt water for making bean curd was analyzed and it consisted of calcium and other salts without harmful heavy metals. We induced a similar phenomenon by experimental application of commercial salt water on guinea pigs.

CONCLUSION

Bean curd is used as a food commonly in the Far-East, allowing a greater chance of exposure to salt water accidentally or occupationally. Bean curd is becoming more popular even in Western countries. To confirm causation, we induced a similar phenomenon in guinea pigs by experimental application of commercial salt water.

Saturation of azimuthal anisotropy in Au + Au collisions at (square root)s(NN) = 62-200 GeV

New measurements are presented for charged hadron azimuthal correlations at midrapidity in Au+Au collisions at (square root)s(NN) = 62.4 and 200 GeV. They are compared to earlier measurements obtained at (square root)s(NN) = 130 GeV and in Pb + Pb collisions at (square root)s(NN) = 17.2 GeV. Sizeable anisotropies are observed with centrality and transverse momentum (pT) dependence characteristic of elliptic flow (upsilon2). For a broad range of centralities, the observed magnitudes and trends of the differential anisotropy, upsilon2(pT), change very little over the collision energy range (square root)s(NN) = 62-200 GeV, indicating saturation of the excitation function for upsilon2 at these energies. Such a saturation may be indicative of the dominance of a very soft equation of state for (square root)s(NN) approximately 60-200 GeV.