bluuebunny/crossref_metadata_2025 huggingface dataset:
A scanning electron microscope for ultracold atoms
Authors: Gericke T , Utfeld C , Hommerstad N , Ott H
Published: May 2006

We propose a new technique for the detection of single
atoms in ultracold quantum gases. The technique is based on
scanning electron microscopy and employs the electron impact
ionization of trapped atoms with a focused electron probe.
Subsequent detection of the resulting ions allows for the
reconstruction of the atom's position. This technique is expected
to achieve a much better spatial resolution compared to any
optical detection method. In combination with the sensitivity to
single atoms, it makes new in situ measurements of atomic
correlations possible. The detection principle is also well suited
for the addressing of individual sites in optical lattices.
On the proof theory of type two functionals based on primitive recursive operations
Authors: Steiner David , Strahm Thomas
Published: May 2006

This paper is a companion to work of Feferman, Jäger, Glaß, and Strahm on the proof theory of the type two functionals μ and E1 in the context of Feferman‐style applicative theories. In contrast to the previous work, we analyze these two functionals in the context of Schlüter's weakened applicative basis PRON which allows for an interpretation in the primitive recursive indices. The proof‐theoretic strength of PRON augmented by μ and E1 is measured in terms of the two subsystems of second order arithmetic, Π10‐CA and Π11‐CA, respectively. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Omitting types in fuzzy logic with evaluated syntax
Authors: Murinová Petra , Novák Vilém
Published: May 2006

This paper is a contribution to the development of model theory of fuzzy logic in narrow sense. We consider a formal system EvŁ of fuzzy logic that has evaluated syntax, i. e. axioms need not be fully convincing and so, they form a fuzzy set only. Consequently, formulas are provable in some general degree. A generalization of Gödel's completeness theorem does hold in EvŁ. The truth values form an MV‐algebra that is either finite or Łukasiewicz algebra on [0, 1].

The classical omitting types theorem states that given a formal theory T and a set Σ(x 1, … , xn ) of formulas with the same free variables, we can construct a model of T which omits Σ, i. e. there is always a formula from Σ not true in it. In this paper, we generalize this theorem for EvŁ, that is, we prove that if T is a fuzzy theory and Σ(x 1, … , xn ) forms a fuzzy set , then a model omitting Σ also exists. We will prove this theorem for two essential cases of EvŁ: either EvŁ has logical (truth) constants for all truth values, or it has these constants for truth values from [0, 1] ∩ ℚ only. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The effects of the selective estrogen receptor modulators, methyl‐piperidino‐pyrazole (MPP), and raloxifene in normal and cancerous endometrial cell lines and in the murine uterus
Authors: Davis Angela M. , Ellersieck Mark R. , Grimm Kristie M. , Rosenfeld Cheryl S.
Published: May 2006

Since estrogens have vital functions in the uterus but might also contribute to endometrial cancer, we sought to determine the in vitro effects of methyl‐piperidino‐pyrazole (MPP), raloxifene, and β‐estradiol on Ishikawa and RL‐95 endometrial cancer, and ovine luminal endometrial (oLE) cell lines and the in vivo effects of these compounds in the rodent uterus. MPP and raloxifene (1 nM) induced significant apoptosis in the endometrial cancer and oLE cell lines compared to β‐estradiol treated and control cells (P ≤ 0.0001–0.001). To determine the in vivo uterine effects of these compounds, ovariectomized wild‐type (WT) and estrogen receptor‐β knockout (ERβKO) mice were treated with 25, 50, 100, or 150 µg of each compound. Although raloxifene caused no significant increase in uterine weight, the presumptive ERα antagonist, MPP (25–150 µg) increased uterine weight, and cell proliferation significantly relative to vehicle control in WT and ERβKO mice (P ≤ 0.001). However, MPP did not increase uterine wet weight as effectively as β‐estradiol (P ≤ 0.0001), and administration of either 50 µg of MPP or raloxifene effectively reversed the positive effects of 50 and 100 µg β‐estradiol. Unexpectedly, in view of the in vitro studies, MPP and raloxifene treatment of ovariectomized mice did not induce apoptosis of the luminal epithelial cells but rather these compounds induced apoptosis of the underlying uterine stromal cells. These results demonstrate that MPP and raloxifene can exert apparently contrasting in vitro versus in vivo effects, and that they have mixed agonist/antagonist action on murine uterine ERα in vivo. Mol. Reprod. Dev. 1034–1044, 2006. © 2006 Wiley‐Liss, Inc.
C2v nitrogen‐hydrogen complexes in GaAsN revealed by X‐ray Absorption Near‐Edge Spectroscopy and ab initio simulations
Authors: Ciatto G. , Boscherini F. , Amore Bonapasta A. , Filippone F. , Polimeni A. , Capizzi M.
Published: May 2006

Hydrogenation of GaAsN alloys has recently attracted great interest thanks to the possibility of passivating in a tunable way the large band gap reduction induced by N incorporation. Even if, nowadays, it is well established that the formation of N‐H complexes is at the origin of N passivation, uncovering the structure of the complex responsible for the experimental observations represents a more difficult task. In this work, we combine X‐ray Absorption Near Edge Spectroscopy (XANES) at the nitrogen K‐edge with ab‐initio simulations to investigate the atomic geometry of N‐H complexes in hydrogenated GaAsN; simulations are performed in a Real Space‐Full Multiple Scattering approach. We provide evidence that a dihydrogennitrogen complex with C2v symmetry is the most abundant species in hydrogenated GaAsN. We show that the use of very large atomic clusters and of broadening terms in the potential are necessary in order to reproduce the experimental data. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Schottky gate effects on transport properties of Al0.35Ga0.65N/GaN heterostructures
Authors: Asgari A. , Kalafi M. , Faraone L.
Published: May 2006

The effects of the Schottky gate on transport properties of Al0.35Ga0.65N/GaN heterostructure‐based high electron mobility transistor parameters such as the two‐dimensional electron gas density, two‐dimensional electron mobility and current–voltage characteristics were determined by using exact numerical methods including transferred electron effects from 2‐dimensional to 3‐dimensional states. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Prolonged kinetics of photoluminescence of two‐dimensional electron gas in AlGaN/GaN heterostructure
Authors: Shamirzaev T. S. , Korzhavina N. S. , Mansurov V. G. , Preobrazhenskii V. V. , Zhuravlev K. S.
Published: May 2006

AlGaN/GaN heterostructure with a two dimensional electron gas (2DEG) has been studied by cw and transient photoluminescence (PL). Low temperature cw PL spectra of the heterostructure demonstrate a line connected with the 2DEG in the spectral region between excitonic and band to acceptor transitions of the CaN layer. The line demonstrates a non‐exponential decay with duration of several tens microseconds and a red shift with time after an excitation pulse. The PL kinetics of the 2DEG was explained in framework of a model taking into account spatial separation of two‐dimensional electrons and holes localized at acceptors located in a space‐charge region of the GaN layer. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Inhibitory effect of polar oregano extracts on aldose reductase and soybean lipoxygenase in vitro
Authors: Koukoulitsa Catherine , Zika Chariklia , Hadjipavlou–Litina Dimitra , Demopoulos Vassilis J. , Skaltsa Helen
Published: May 2006

The effect of methanol and aqueous methanol extract of Origanum vulgare L. ssp. hirtum on aldose reductase and soybean lipoxygenase was investigated. The results revealed a promising potential of oregano for preventing diabetes complications in the long term and an antiinflammatory efficacy by inhibiting soybean lipoxygenase. Copyright © 2006 John Wiley & Sons, Ltd.
Effect of various extracts and a polysaccharide from the edible mycelia of Cordyceps sinensis on cellular and humoral immune response against ovalbumin in mice
Authors: Wu Yalin , Sun Hongxiang , Qin Feng , Pan Yuanjiang , Sun Cuirong
Published: May 2006

In this study, the edible mycelia of Cordyceps sinensis (Berk.) Sacc. were sequentially extracted by petroleum ether, ethyl acetate, ethanol and ultrasonic water‐bath (75 °C), and the water extract was further isolated by Sephadex G‐100 to afford a petroleum ether extract (PE), ethyl acetate extract (EAE), ethanol extract (EE), glycoprotein (GP) and a purified polysaccharide (PS). In combination with component analysis, the isolated PS showed d‐Glc, d‐Man, l‐Ara and d‐Gal in a molar ratio of 8:90:1:1. The average molecular weight of PS was determined as ∼8.3 × 104. The immunomodulatory potentials of these samples (PE, EAE, EE, GP and PS) at three dose levels on the cellular and humoral immune responses of ICR mice against ovalbumin (OVA) were studied. ICR mice were immunized subcutaneously with 100 µg OVA alone or with 100 µg OVA dissolved in saline containing these samples (100, 200 or 400 µg) on days 1 and 15. Two weeks later (day 28), concanavalin A (Con A)‐ and OVA‐stimulated splenocyte proliferation and OVA‐specific antibody in serum were investigated. These samples, except for PS, significantly enhanced the Con A‐ and OVA‐induced splenocyte proliferation in OVA‐immunized mice at a suitable dose (p < 0.05 or p < 0.01). OVA‐specific IgG, IgG1 and IgG2b antibody levels in serum were significantly enhanced by these extracts and PS compared with the OVA control group (p < 0.05, p < 0.01 or p < 0.001). Copyright © 2006 John Wiley & Sons, Ltd.
Understanding Free/Open Source Software Development Processes
Authors: Scacchi Walt , Feller Joseph , Fitzgerald Brian , Hissam Scott , Lakhani Karim
Published: May 2006

This article introduces a special issue ofSoftware Process—Improvement and Practicefocusing on processes found in free or open source software development (F/OSSD) projects. It seeks to provide a background overview of research in this area through a review of selected empirical studies of F/OSSD processes. The results and findings from a survey of empirical studies of F/OSSD give rise to an interesting variety of opportunities and challenges for understanding these processes, which are identified along the way. Overall, what becomes clear is that studies of F/OSSD processes reveal a more diverse set of different types of processes than have typically been examined in conventional software development projects. The articles in this special issue further advance understanding of what processes characterize and shape F/OSSD. Copyright © 2006 John Wiley & Sons, Ltd.
Usability processes in open source projects
Authors: Nichols David M. , Twidale Michael B.
Published: May 2006

We explore how some open source projects address issues of usability. We describe the mechanisms, techniques and technology used by open source communities to design and refine the interfaces to their programs. In particular we consider how these developers cope with their distributed community, lack of domain expertise, limited resources and separation from their users. We also discuss how bug reporting and discussion systems can be improved to better support bug reporters and open source developers. Copyright © 2006 John Wiley & Sons, Ltd.
Techniques and processes for improving the quality and performance of open‐source software
Authors: Porter Adam , Yilmaz Cemal , Memon Atif M. , Krishna Arvind S. , Schmidt Douglas C. , Gokhale Aniruddha
Published: May 2006

Open‐source development processes have emerged as an effective approach to reduce cycle‐time and decrease design, implementation, and quality assurance (QA) costs for certain types of software, particularly systems infrastructure software, such as operating systems (OS), compilers and language processing tools, text and drawing editors, and middleware. This article presents two contributions to the study of open‐source software processes. First, we describe key challenges of open‐source software and illustrate how QA processes—specifically those tailored to open‐source development—help mitigate these challenges better than traditional closed‐source processes do. Second, we summarize results of empirical studies that evaluate how our Skoll distributed continuous quality assurance (DCQA) techniques and processes help to resolve key challenges in developing and validating open‐source software. Our results show that: (a) using models to configure and guide the DCQA process improves developer understanding of open‐source software, (b) improving the diversity of platform configurations helps QA engineers find defects missed during conventional testing, and (c) centralizing control of QA activities helps to eliminate redundant work. Copyright © 2006 John Wiley & Sons, Ltd.
Inhibition byl‐phenylalanine of tryptophan transport by synaptosomal plasma membrane vesicles: Implications in the pathogenesis of phenylketonuria
Authors: Herrero E. , Aragon M. C. , Gimenez C. , Valdivieso F.
Published: May 2006

Phenylalanine is accumulated in the genetically linked deficiency phenylketonuria. The effect ofl‐phenylalanine on the transport of tryptophan was studied using membrane vesicles from rat‐brain synaptosomes. Phenylalanine at similar concentrations to those found in phenylketonuric patients competitively inhibits tryptophan uptake, with aKiof the same order as theKmfor tryptophan. This inhibition could be responsible for the depletion of serotonin found in phenylketonuria.
Kinetic analysis of argininosuccinate synthetase in a variant form of citrullinaemia
Authors: Akaboshi I. , Endo F. , Matsuda I. , Saheki T.
Published: May 2006

Argininosuccinate (ASA) synthetase in the liver from a patient with a variant form of citrullinaemia was analysed. Serum citrulline level was approximately 40 times higher than the control level, and the ASA synthetase activity was approximately 10% that of the control. Other urea cycle enzymes were within normal ranges. The specific activity (enzyme activity/enzyme protein, measured by immunochemical method), pH optimum, Michaelis constants, and thermal denaturation in the presence or absence of ASA were similar to those in enzymes obtained from the normal and the patient's liver cells. Noin vitro effect of the patient's liver homogenate on ASA synthetase in normal liver was observed. Serum citrulline levels of the patient's parents and young brother were at the maximal level of control at fasting and definitely elevated 4 h after citrulline loading (100 mg/kg).
Evidence for defective threonine metabolism in non‐ketotic hyperglycinaemia
Authors: Krieger I. , Nigro M.
Published: May 2006

Experience with two cases of non‐ketotic hyperglycinaemia has provided some evidence for defective threonine metabolism.
Neuroblastoma: an analysis of 160 cases
Authors: Grosfeld Jay L. , Baehner Robert L.
Published: May 2006

Neuroblastoma was observed in 160 patients from 1948–1978. Ninety‐seven patients were boys and 63 were girls. At diagnosis, 74 patients were less than 2 years of age, 28 between 2–3 years, and 58 over 3 years. Sixty‐two (38%) patients had localized disease, while 98 (62%) had metastases. Patients were grouped by extent of disease according to the staging criteria of Evans et al.: stage I (5), stage II (31), stage III (26), stage IV (82), stage IV‐S (16). Tumors occurred in the neck (3), mediastinum (16), abdomen (136), and pelvis (3). Clinical findings often included abdominal mass, weight loss, anemia, bone pain, and proptosis. Six patients had diarrhea and 3 had cerebellar ataxia and nystagmus. Lesions were often calcified (>50%), and bone marrow aspirate frequently demonstrated tumor clumps (rosettes). Urinary VMA was elevated in 85% of cases.

Therapy varied according to stage. Stage I patients received operative excision alone and stage II patients operative resection with radiation for residual tumor and/or positive lymph nodes. Stage III patients were managed aggressively with operative resection (when possible), irradiation, and combination chemotherapy (cyclophosphamide, vincristine, DTIC, Adriamycin®, VM‐26). Patients with metastases (stage IV) were initially treated with multiagent chemotherapy with late “second‐look” or delayed primary laparotomy for tumor resection done in clinical responders.

Two‐year disease‐free survival occurred in 57 of 160 patients or 35.6%. Survival rates were best for infants under age 1 year (74%) and for patients with stage I (100%), stage II (74%) and stage IV‐S (75%) tumors. There was improved survival in patients with tumors that occurred in the neck (100%), pelvis (100%), and mediastinum (75%). Survival rates were poor in patients over 2 years of age (13–17%), with abdominal tumors (28%), and with stage III (34%) and stage IV (10%) tumors. While chemotherapy and irradiation have improved tumor response, survival rate has not been improved. Immunotherapy has been disappointing. Unfortunately, at the present time, there is no specific chemotherapeutic agent that has a curative effect on this tumor.
Pyogenic liver abscess
Authors: McDonald Anthony P. , Howard Richard J.
Published: May 2006

Pyogenic liver abscess has been recognized since ancient times and it continues to be associated with substantial morbidity and mortality. This paper is a summary of the clinical manifestations of pyogenic hepatic abscess.
Esophageal intubation for carcinoma of the esophagus
Authors: Procter Desmond S. C.
Published: May 2006

Over 2500 cases of esophageal carcinoma were studied, the large majority having incurable disease. Most palliative measures have proved unsatisfactory to date, especially in patients unfit for “active” palliation such as surgery or radiotherapy. The most effective palliation achieved in the cases studied was by means of the Procter‐Livingstone endoesophageal tube, which achieves immediate palliation and can be inserted by a simple technique, almost as an outpatient procedure. The prosthesis is safe and quick to insert, in most cases by esophagoscopy. The results have been most satisfactory under the circumstances, with a low operative mortality rate and almost no morbidity. The technique has been especially useful with fistulae. The commonest complication has been proximal displacement of the tube. A newer design is now used which effectively prevents this. Other complications have been the same as those that accompany esophagoscopy itself. This method of intubation should not be regarded as a favorable alternative to surgery where this is possible. Compared to 18 other prostheses described in the literature, the one that we have used is much safer, quicker, and easier to insert.
Analysis of 607 cases of choledochal sphincterotomy
Authors: Arianoff André A.
Published: May 2006

This is a report of the morbidity and mortality rates in 607 patients who underwent sphincterotomy (SPH), 324 of whom were more than 60 years of age. During the operation there were technical errors in 6 cases; a false passage was made in 5 (and recognized in 4); and the duodenal wall was lacerated and repaired in 1. Postoperative morbidity developed in 43 patients (7.1%) and included general disorders in 16 (2.6%), operative complications unrelated to SPH in 12 (2.0%), and complications due to SPH in the remaining 15 (2.5%). The SPH‐related complications included hemobilia (5 cases), subphrenic or perinephric abscess (4 cases), and biliary or jejunal fistula (3 cases). Postoperative mortality rate was 3.1% (19 cases). Eight of these deaths (1.3%) were due to abdominal complications which included acute pancreatitis (4), hemobilia (2), biliary fistula (2), and duodenal fistula (1). Of 544 patients reviewed after more than 1 year, there were only 12 failures (2.2%) and 23 minor sequelae. It is concluded that sphincterotomy, if correctly performed, is associated with low morbidity and mortality rates, and excellent long‐term results in 94% of patients.
The biology and control of surface overhealing
Authors: Cohen I. Kelman , McCoy Barbara J.
Published: May 2006

Lesions of “surface overhealing” include keloid, hypertrophic scar, and burn scar. All are characterized by overabundant collagen deposition. The biology of these lesions is reviewed, suggesting that abnormal collagen metabolism results from alterations in the inflammatory/immune response. Practical and theoretical treatment plans are outlined based on methods that alter collagen metabolism, the inflammatory/immune system or rely on physical alterations (surgery, pressure).
Monitoring heparin therapy with thromboelastography and activated partial thromboplastin time
Authors: Lee Bok Y. , Taha Salah , Trainor Frieda S. , Kavner David , McCann William J.
Published: May 2006

Blood coagulability in patients undergoing anticoagulant therapy has been studied using the Thromboelastograph® and activated partial thromboplastin time. Currently used tests, such as activated partial thromboplastin time (APTT) and whole blood clotting time, lack sensitivity and do not correlate well with clinically significant bleeding and clotting events. The Thromboelastograph® is an instrument that allows continuous measurement of overall coagulation and fibrinolysis. Sixty patients on heparin therapy were monitored with thromboelastography and activated partial thromboplastin time. Continuous heparin infusion or intermittent administration was used. The Thromboelastograph® was found to be a more sensitive device for detection of response to heparin than APTT. Early response to heparin was reflected in the reaction time, k time, and maximum amplitude of the thromboelastogram. A more precise administration of heparin was made possible, resulting in use of less heparin and a more stable patient response. A more individualized approach to the patient's therapy was achieved by monitoring with the Thromboelastograph, and the best results were obtained with continuous infusion rather than intermittent administration of heparin.
Results of acute and chronic experiments with assisted and total artificial heart
Authors: Taguchi Kazumi , Mochizuki Takaaki , Nakagaki Mitsuru , Kado Shigenobu , Takamura Keiichi , Miyoshi Nobukasu , Murashita Junji , Maruyama Takashi , Matsumara Makato
Published: May 2006

An assisted artificial heart and a total artificial heart were implanted in 108 calves. Two types of assisted artificial heart, a bladder type and a diaphragm type made of silastic and segmented polyurethane, were tested in left atrial (LA) or left ventricular (LV) to abdominal aorta bypass. Of 40 calves that received LA bypass, 6 survived for more than 100 hours. Of 35 calves that received LV bypass, 18 survived for more than 100 hours. In the total artificial heart experiments, an oval‐ or sphere‐shaped total artificial heart was implanted in 13 calves after 20 pilot experiments. That longest survival period was 864 hours (about 36 days), and the average survival time was 8.5 days.
Selective proximal vagotomy in the treatment of duodenal ulcer
Authors: Kuzin M. I. , Postolov P. M.
Published: May 2006

Selective proximal vagotomy (SPV) was performed in 210 patients and SPV with pyloroplasty (SPV + PP) in 31 patients with duodenal ulceration. Following SPV alone, BAO was decreased by 92.4%, MAO after histamine stimulation by 74.3%, and MAO after insulin stimulation by 99.7%. Following SPV + PP, the reductions were 90%, 73%, and 92.5%, respectively. SPV did not suppress gastric acid secretion as extensively as partial gastrectomy, or vagotomy with antrectomy. The function of the liver, gallbladder, and pancreas, which may be disturbed by peptic ulcer disease, returned to normal after SPV. The postoperative mortality rate for SPV was 0.5%, and postoperative complications were uncommon. The incidence of recurrent ulcer was 1.9%.
Progress in the treatment of ruptured abdominal aortic aneurysm
Authors: Lawrie Gerald M. , Crawford E. Stanley , Morris George C. , Howell Jimmy F.
Published: May 2006

This report summarizes the clinical, pathological, and surgical aspects of ruptured abdominal aortic aneurysm. The significant risk of rupture of these aneurysms is well documented. Although large aneurysms are more prone to rupture, the risk of rupture of small aneurysms less than 4 cm in diameter is well established. While most aneurysms are a result of atherosclerosis, a small number are mycotic in origin or secondary to a dissection trauma or previous aortic surgery. Rupture of abdominal aneurysms occurs into the retroperitoneum in about ¾ of cases, and into the peritoneal cavity in the remainder. Occasionally rupture occurs into the small bowel or the inferior vena cava with fistula formation. The classical clinical features are abdominal or back pain, hypotension, and a pulsatile tender abdominal mass, but in many cases diagnosis has been delayed because of atypical presentations, in particular the absence of hypotension. Successful treatment requires immediate operation with control of the proximal abdominal aorta. Graft replacement is then performed. Avoidance of technical problems is essential, in particular damage to the great veins. Utilizing these principles we have achieved a major reduction in mortality rate in our own experience. In a series of 61 patients, overall mortality was only 14.8%. The causes of death were related to preoperative hypotension causing acute myocardial infarction, renal failure, and respiratory failure. The major factors responsible for these improved results were immediate operation with rapid proximal aortic control, avoidance of left thoracotomy, absence of technical errors, and expeditious completion of the surgical procedure. Despite these improved results, emphasis must continue to be placed on prevention of rupture by diagnosis and treatment of the unruptured aneurysm.
Current status of medical therapy of acute dissecting aneurysms of the aorta
Authors: Wheat Myron W.
Published: May 2006

In 6 series of patients with acute dissecting aneurysms of the aorta reported during 1970–1979, the best results were obtained by intensive drug therapy initially to correct hypertension and stabilize the patient, then diagnosis by aortography, and then surgical repair for Type A aneurysms involving the ascending aorta, and drug therapy alone for Type B aneurysms involving the descending thoracic aorta. Using this plan of treatment, mortality rates were 30% in patients with Type A dissections (surgical therapy) and 20% in those with Type B dissections (drug therapy).
Portal Hypertension: Contraindication to Liver Surgery?
Authors: Capussotti Lorenzo , Ferrero Alessandro , Viganò Luca , Muratore Andrea , Polastri Roberto , Bouzari Hedayat
Published: May 2006

Introduction

In recent decades liver resection has become a safe procedure, mainly because of better patient selection. Despite this progress, however, outcomes of hepatectomy in cirrhotic patients with portal hypertension are still uncertain. The aim of this study was to elucidate early and long‐term outcomes of liver resection in these patients.

Methods

Between 1985 and 2003, a total of 245 cirrhotic patients underwent hepatectomy for HCC. Altogether, 217 patients were eligible for this analysis and were divided into two groups according to the presence of portal hypertension at the time of surgery: 99 patients with portal hypertension and 118 without it.

Results

Patients with portal hypertension had worse preoperative liver function (Child‐Pugh A class patients: 66.7% vs. 94.9%; P < 0.0001). No differences were encountered in terms of intraoperative and pathology data. Operative mortality was similar (11.1% vs. 5.1%; P = 0.100), but patients with portal hypertension had higher morbidity (43.4% vs. 30.5%; P = 0.049) and received a higher rate of blood and plasma transfusions (51.5% vs. 32.2%, P = 0.004; 77.8% vs. 57.6%, P = 0.0017). Considering only Child‐Pugh A patients, short‐term results were similar in the two groups in terms of mortality, morbidity, and transfusion rates. The 5‐year survival rate was significantly higher in patients without portal hypertension (39.8% vs. 28.9%; P = 0.020), although when considering only Child‐Pugh A patients no difference of survival was encountered. Multivariate analysis identified Child‐Pugh classification, tumor diameter, and vascular invasion as independent predicting factors for survival.

Conclusions

Portal hypertension should not be considered an absolute contraindication to hepatectomy in cirrhotic patients. Child‐Pugh A patients with portal hypertension have short‐ and long‐term results similar to patients with normal portal pressure.
Major Hepatectomy in Children: Approaching Blood Transfusion‐free
Authors: Lin Chih‐Che , Chen Chao‐Long , Cheng Yu‐Fan , Chiu King‐Wah , Jawan Bruno , Hsaio Chih‐Cheng
Published: May 2006

Introduction

Major hepatectomy complicated with massive blood loss requires blood transfusion, which may result in increased morbidity and mortality. Intraoperative techniques and postoperative management that achieves blood transfusion‐free major hepatectomy in children are described.

Methods

Fourteen children with a mean age of 3.1 years and mean body weight of 14 kg underwent major hepatectomy between May 1994 and September 2002. Demographic information, surgical techniques, and intraoperative management were analyzed.

Results

Hepatectomy included right trisegmentectomy in seven cases, extended right lobectomy in three, right lobectomy in two, and left lobectomy in two. Preoperative imaging, hemihepatic inflow control, intraoperative ultrasonography, and ultrasonic dissection were routinely applied. Fluid was restricted to target a low central venous pressure (5 cm H2O) during transection. Postoperative low hemoglobin (>6.3 g/dl) was tolerated in pediatric patients. There was no operative mortality or major complications and only two cases of pleural effusion. The mean blood loss was 68 ml (range 1.25–13.0 ml/kg), and no blood transfusions were required intraoperatively. Blood transfusion was given because of a liberal strategy for major operation in two patients and preoperative tumor bleeding in one.

Conclusions

Despite being technically challenging, major hepatectomy can be performed with minimal blood loss and without blood transfusion in children to decrease postoperative complications.
Cell cycle analysis of in vitro cultured goral (Naemorhedus caudatus) adult skin fibroblasts
Authors: Hashem Md. Abul , Bhandari Dilip P. , Kang Sung Keun , Lee Byeong Chun , Suk Hwang Woo
Published: May 2006

The present study was undertaken to examine cell cycle characteristics of endangered Goral (CITES Appendix I) adult skin fibroblasts. Seven experiments were performed, each with a one‐way completely randomized design involving three replicates. Least significant difference (LSD) was used to determine variation among treatment groups. Experiment I focused on the effects of cycling, serum‐starved, and fully confluent stages of Goral cells. In Experiments II and III, the effects of different antioxidants like β‐mercaptoethanol (β‐ME, 10 μM), cysteine (2 mM), and glutathione (2 mM) were examined after cells were fully confluent without serum starvation for 24 h and 4 h, respectively. In Experiments IV and V, three protease inhibitors, namely 6‐dimethylaminopurine (6‐DMAP, 2 mM), cycloheximide (7.5 μg/ml) and cytochalasin B (7.5 μg/ml), were used as in Experiment II. In Experiments VI and VII, the effect of different levels of dimethylsulphoxide (DMSO) at 0%, 0.5%, 1.0% and 2.5% were tested by flow cytometry (FACS). In Experiment I, 68.7% of Goral skin fibroblasts reached the G0/G1stage (2C DNA content) when subjected to the serum‐starved medium, which was more than the cycling (64.9%) and fully confluent groups (61.0%) (P> 0.05). Among the chemically treated group, β‐ME, cysteine and DMSO showed better results for synchronization of G0+ G1phases than cycling, serum‐starved and fully confluent groups. It can thus be concluded that β‐ME, cysteine and DMSO at certain concentrations can synchronize the cell cycle effectively, which could have a positive impact on somatic cell nuclear transfer in the goral.
Epidemiology and genetic characterization of Shigella flexneri strains isolated from three paediatric populations in Egypt (2000–2004)
Authors: AHMED S. F. , RIDDLE M. S. , WIERZBA T. F. , MESSIH I. ABDEL , MONTEVILLE M. R. , SANDERS J. W. , KLENA J. D.
Published: May 2006

Ninety-seven isolates of Shigella flexneri from children seeking medical care from three sites in Egypt were characterized. Overall, 46·4% of children (median age 17 months) were febrile or reported blood in their stools, 25·8% were dehydrated and 16·5% were admitted to hospital. Serotypes 2a (37·1%), 1b (18·6%), 1c (17·5%), and 6 (15·5%) comprised over 88·7% of the total isolates. We observed marked resistance to ampicillin (87·6%), tetracycline (84·5%) and trimethoprim–sulfamethoxazole (63·9%). Pulsed-field electrophoresis grouped the majority of isolates within a serotype together, separately from isolates of an alternative serotype. The set gene was present in all serogroup 2a isolates, however, the sen gene was detected in every isolate. Our results show S. flexneri 1c has emerged as a dominant S. flexneri serotype in Egypt. Development and application of a Shigella vaccine should consider the diversity of Shigella serotypes within a geographical region prior to administration.
State space computation and analysis of Time Petri Nets
Authors: GARDEY GUILLAUME , ROUX OLIVIER H. , ROUX OLIVIER F.
Published: May 2006

The theory of Petri Nets provides a general framework to specify the behaviors of real-time reactive systems and Time Petri Nets were introduced to take also temporal specifications into account. We present in this paper a forward zone-based algorithm to compute the state space of a bounded Time Petri Net: the method is different and more efficient than the classical State Class Graph. We prove the algorithm to be exact with respect to the reachability problem. Furthermore, we propose a translation of the computed state space into a Timed Automaton, proved to be timed bisimilar to the original Time Petri Net. As the method produce a single Timed Automaton, syntactical clocks reduction methods (DAWS and YOVINE for instance) may be applied to produce an automaton with fewer clocks. Then, our method allows to model-check T-TPN by the use of efficient Timed Automata tools.
How defined contribution plans and 401(k)s affect employer pension costs
Authors: GHILARDUCCI TERESA , SUN WEI
Published: May 2006

We investigate the pension choices made by over 700 firms between 1981 and 1998 when DC plans expanded and overtook DB plans. Their average pension contribution per employee dropped in real terms from $2,140 in 1981 to $1,404 in 1998. At the same time, the share of their pension contributions attributed to defined contribution plans was 23% in 1981 and increased to 68% in 1998. By analyzing pension plan data from the IRS Form 5500 and finances of the plan's sponsoring employer from COMPUSTAT with a fixed-effects ordinary least squares model and a simultaneous model, we find that a 10% increase in the use of defined contribution plans (including 401(k) plans) reduces employer pension costs per worker by 1.7–3.5%. This suggests firms use DCs and 401(k)s to lower pension costs. Lower administrative expenses may also explain the popularity of DC plans. Although measuring a firm's pension cost per worker may be a crude way to judge a firm's commitment to pensions, this study suggests that firms that provide both a traditional defined benefit and a defined contribution plan are the most committed because they spend the most on pensions. Further research, especially case studies, is vital to understand employers' commitment to employment-based pension plans.
HMG‐CoA reductase inhibition causes neurite loss by interfering with geranylgeranylpyrophosphate synthesis
Authors: Schulz Joachim G. , Bösel Julian , Stoeckel Magali , Megow Dirk , Dirnagl Ulrich , Endres Matthias
Published: May 2006

To determine whether neurite outgrowth depends upon the mevalonate pathway, we blocked mevalonate synthesis in nerve growth factor‐treated PC12 cells or primary cortical neurones with atorvastatin, a 3‐hydroxymethylglutaryl coenzyme A (HMG‐CoA) reductase inhibitor, and substituted different intermediates of the mevalonate pathway. We show that HMG‐CoA reductase inhibition causes a profound reduction of neurite length, neurite loss and ultimatively cell death in undifferentiated and pre‐differentiated PC12 cells and also in rat primary cortical neurones. Geranylgeranylpyrophosphate, but not farnesylpyrophosphate, squalene or cholesterol, completely compensated for the lack of mevalonate. Our data indicate that, under HMG‐CoA reductase inhibition, geranylgeranylpyrophosphate rather than farnesylpyrophosphate or cholesterol is critical for neurite outgrowth and/or maintenance. Loss of neurites is an early manifestation of various neurodegenerative disorders, and dysfunction of isoprenylation might play a role in their pathogenesis.
Unsuccessful Acupuncture Conversion of Breech Presentation
Authors: Vuković-Bobić M. , Habek D.
Published: May 2006

A case is presented of fetal oblique position with compound presentation, where acupuncture conversion of breech presentation failed due to the umbilical being wrapped three times
around the fetus with a knot in the umbilical cord, so that delivery was terminated by cesarean section. Conversion of the fetal breech presentation was induced by manual acupuncture
stimulation of the UB 67 acupoint with simultaneous CTG control in the 35th week of pregnancy. During the first acupuncture stimulation, CTG showed protracted uterine contraction with
subsequent regular low amplitude contractions with intensified fetal activity and CTG curve reactivity. In the 39th week of gestation, the patient felt regular contractions verified by
CTG records showing reactive curves. Obstetrical examination revealed a cervical dilatation of 4 cm, a compound presentation involving both legs and the umbilical cord, and oblique
position. Therefore, a cesarean section according to a modified Misgav-Ladach method was performed and the patient gave birth to a healthy male neonate (3330 g, 49 cm, Apgar 10/10, pH
7.334). The obstetrician should warn the patient of the potential risks and complications associated with any method of breech presentation conversion.
On the multistep ionizations in an argon inductively coupled plasma
Authors: Lee Min-Hyong , Jang Sung-Ho , Chung Chin-Wook
Published: May 2006

The effect of the multistep ionizations on the plasma parameters in the inductively coupled plasma (ICP) has been investigated by experiments and theory. To obtain electron density and electron temperature precisely at various powers and pressures in the ICP, the electron energy distribution functions (EEDFs) are measured. It is found that at high pressures, the electron temperature from the EEDFs decreases and the electron density increases rapidly with the absorbed power while, at low pressures, the electron temperature is hardly changed and the electron density is almost linearly proportional to the absorbed power. The comparison between the experiment and our model including the multistep ionizations [M. H. Lee and C. W. Chung, Phys. Plasmas 12, 73501 (2005)] was done and the experiment was in close agreement with the model. This shows that the changes in the electron density and the electron temperature in the ICP are mainly due to the multistep ionizations.
Excitation of nonlinear electron acoustic waves
Authors: Valentini Francesco , O’Neil Thomas M. , Dubin Daniel H. E.
Published: May 2006

A particle in cell (PIC) simulation is used to investigate the excitation of electron acoustic waves (EAWs) and the stability of the EAWs against decay. An EAW is a nonlinear wave with a carefully tailored trapped particle population, and the excitation process must create the trapped particle population. For a collisionless plasma, successful excitation occurs when a relatively low amplitude driver that is spatially and temporally resonant with the EAW is applied for a sufficiently long time (many trapping periods). The excited EAW rings at a nearly constant amplitude long after the driver is turned off, provided the EAW has the largest wavelength that fits in the simulation domain. Otherwise, the excited EAW decays to a longer wavelength EAW. In phase space, this decay to longer wavelength appears as a tendency of the vortex-like trapped particle populations to merge. In a collisional plasma, successful excitation of an EAW requires the driver amplitude to exceed a threshold value. The period for a trapped particle oscillation must be short compared to the time for collisions to smooth out the trapped particle plateau.
Magnetic topology effects on Alcator C-Mod flows
Authors: Catto Peter J. , Simakov Andrei N.
Published: May 2006

The effect of magnetic topology on ion and impurity flows in a tokamak is considered by investigating the consequences of (i) the reversal of toroidal and poloidal magnetic fields and currents; (ii) a switch from lower to upper X-point operation; (iii) poloidal magnetic field or plasma current reversal, and (iv) toroidal magnetic field reversal. The general symmetries associated with magnetic topology changes in tokamaks are employed to demonstrate that the flux surface flows inside and outside the separatrix observed in Alcator C-Mod [I. H. Hutchinson et al., Phys. Plasmas 1, 1511 (1994)] can be used to determine the flow features, including neoclassical and turbulent effects and in the presence of charge exchange.
Field-induced percolation transition and 100% low-field magnetoresistance in aligned half-metallic nanoparticle arrays
Authors: Cai Tian-Yi , Ju Sheng , Li Zhen-Ya
Published: May 2006

A Monte Carlo simulation is performed to study the relationship between magnetization reversal and magnetotransport in half-metallic nanoparticle arrays. It is found that both the absolute magnitude of low-field magnetoresistance and the switching effect are significantly enhanced when the magnetic anisotropic axes of nanoparticles are aligned along the same direction. Compared with conventional granular ferromagnets, a percolation mechanism is found to dominate, leading to a 100% low-field magnetoresistance in two-dimensional half-metallic nanoparticle arrays. These results also give a deeper insight into the experimental findings, where optimized magnetoresistive effects are found in CrO2 composites with field-aligned CrO2 particles.
Robust Ti4+ states in SrTiO3 layers of La0.6Sr0.4MnO3∕SrTiO3∕La0.6Sr0.4MnO3 junctions
Authors: Kumigashira H. , Chikamatsu A. , Hashimoto R. , Oshima M. , Ohnishi T. , Lippmaa M. , Wadati H. , Fujimori A. , Ono K. , Kawasaki M. , Koinuma H.
Published: May 2006

We have investigated the interfacial electronic structure of La0.6Sr0.4MnO3 (LSMO)∕SrTiO3 (STO)/LSMO heterojunctions utilizing the elemental selectivity of photoemission spectroscopy. The Ti 2p core-level spectra clearly show Ti4+ states and do not exhibit any indication of Ti3+ states in TiO2 layers irrespective of a different kind of adjacent atomic layer with different chemical carrier concentration. This result indicates that the Ti ions in the TiO2 atomic layers preserve their tetravalent states even in the vicinity of the valence-mismatched interface between LSMO and STO, reflecting the chemical stability of the Ti4+ states.
Ultrafast spectral hole burning spectroscopy of exciton spin flip processes in InAs∕GaAs quantum dots
Authors: Müller T. , Strasser G. , Unterrainer K.
Published: May 2006

The exciton spin relaxation within the radiative doublet of the exciton ground state in InAs∕GaAs self-assembled quantum dots is studied via an ultrafast spectral hole burning technique. In the case of cross-polarized pump and probe pulses a spectral “antihole” emerges due to relaxation of the exciton spin. The measured relaxation time decreases rapidly from 1.15ns at T=5Kto90ps at 90K, suggesting exciton-acoustic phonon interaction as the underlying spin relaxation mechanism.
Role of surface nanovoids on interstitial trapping in He implanted crystalline Si
Authors: Mirabella S. , Bruno E. , Priolo F. , Giannazzo F. , Bongiorno C. , Raineri V. , Napolitani E. , Carnera A.
Published: May 2006

The effect of interstitial trapping by surface nanovoids, induced by He ion implantation in crystalline Si, is described. The difference with respect to the effects induced by the deep void layer is evidenced and discussed. Interstitial trapping is investigated by studying the diffusion and the electrical activation of shallow boron implanted in Si. B and He ion implantations were performed on Czochralski bulk and silicon-on-insulator samples in order to isolate the void surface region from the deep void layer. A remarkable reduction of B diffusion is recorded near half the projected range (Rp) of He implantation, which leads to a boxlike shape in the distribution of mobile and electrically active B. Surface nanovoids (2–3nm in size) cause the observed B diffusivity reduction through an enhanced recombination of self-interstitials. Moreover, these surface nanovoids do not hinder the B electrical activation, being the electrically active B dose comparable for the He implanted and the He-free samples. This peculiar effect of He coimplantation at about half the Rp could be used as an efficient interstitial trapping in defect engineering during Si based device processing.
Unusual colossal positive magnetoresistance of the n-n heterojunction composed of La0.33Ca0.67MnO3 and Nb-doped SrTiO3
Authors: Xiong C. M. , Zhao Y. G. , Xie B. T. , Lang P. L. , Jin K. J.
Published: May 2006

An n-n heterojunction composed of La0.33Ca0.67MnO3 and Nb-doped SrTiO3 was fabricated, and it shows good rectifying property. The temperature variation of junction resistance for high reverse voltage exhibits a metal-insulator-like transition that shifts to high temperatures with further increasing voltage. The heterojunction presents a remarkable positive magnetoresistance under the reverse bias voltage at low temperatures, and the maximum of magnetoresistance can even reach ∼400% under a field of 1T. A qualitative explanation is given based on the analysis of the electron filling near the interface and its tunable feature under the bias voltage and magnetic field. This result can be helpful for both the understanding of the manganites and the future applications of the manganite-based devices.
Ultrabroadband near-infrared emission from Bi-doped Li2O–Al2O3–SiO2 glass
Authors: Suzuki Takenobu , Ohishi Yasutake
Published: May 2006

A broad near-infrared emission of Bi-doped lithium alumino silicate glasses has been investigated. It was found that the peak wavelength and width of the emission from the glasses could be controlled drastically by the excitation wavelength. The emission spectrum had the broadest bandwidth of more than 500nm under 900nm excitation. The emission consisted of two Gaussian peaks and the stimulated emission cross sections at the peaks were calculated as 7.3×10−21 and 2.3×10−20cm2. The lifetime was almost independent of temperature up to 350K, indicating that the emission from the Bi-doped lithium alumino silicate glass has strong resistance to the thermal quenching.
Noncontact dielectric constant metrology of low-k interconnect films using a near-field scanned microwave probe
Authors: Talanov Vladimir V. , Scherz André , Moreland Robert L. , Schwartz Andrew R.
Published: May 2006

We present a method for noncontact, noninvasive measurements of dielectric constant k of 100-nm- to 1.5-μm-thick blanket low-k interconnect films on up to 300mm in diameter wafers. The method has about 10μm sampling spot size, and provides <0.3% precision and ±2% accuracy for k value. It is based on a microfabricated near-field scanned microwave probe formed by a 4GHz parallel strip transmission line resonator tapered down to a few micron tip size.