bluuebunny/crossref_metadata_2025 huggingface dataset:
A Facile Synthesis of Sulfones by the Oxidation of Various Sulfides with Oxone in Aprotic Solvent in the Presence of “Wet-Montmorillonite”
Authors: Hirano Masao , Tomaru Jun-ichirou , Morimoto Takashi
Published: May 2006

Oxidation of sulfide with Oxone in dichloromethane in the presence of wet-montmorillonite clay gave sulfones in excellent yields under mild conditions.
A New Approach to L-Daunosamine and L-Acosamine from t-Butyl S-(+)-3-Hydroxybutanoate
Authors: Hatanaka Minoru , Ueda Ikuo
Published: May 2006

A concise synthesis of the N-acyl derivatives of L-daunosamine and L-acosamine is achieved using the highly stereoselective enolate-imine condensation of the lithium dianion of t-butyl S-(+)-3-hydroxybutanoate with N-acylaldimine.
Diastereoselective Introduction of an Allyl Group to the α′-Position of α-Substituted Pyrrolidines through the Intermediate Formation of N-Acyliminium Ions
Authors: Shono Tatsuya , Fujita Tetsuhiro , Matsumura Yoshihiro
Published: May 2006

An allyl group was introduced to the α′-position of α-substituted pyrrolidines and the stereoselectivity of the allylation was investigated. High diastereoselectivities were achieved by modifying the α-substituents or the functional groups located at the nitrogen atom of pyrrolidine ring.
Facile Cleavage of Ge–C Bonds of N-(Germylmethyl)benzylamine Derivatives. Generation of Germyl Anions
Authors: Terunuma Daiyo , Kizaki Hiroaki , Sato Takashi , Masuo Koujiro , Nohira Hiroyuki
Published: May 2006

The reactions of N-(germylmethyl)benzylamine derivatives with butyllithium were carried out. Facile cleavages of Ge–C bonds of the N-benzylgermylmethylamine derivatives giving the corresponding germyl anions and N-pentylbenzylamine were observed. The reaction mechanism of the Ge–C bond cleavage was discussed.
Bacterial contamination of blood components – incidence and significance for homologous and autologous transfusion Bakterielle Kontamination von Blutkomponenten – Inzidenz und Signifikanz für die allogene und autologe Transfusion
Authors: Walther-Wenke Gabriele
Published: May 2006

Successful reduction of the risk of viral transmission via blood components has emphasized the risk of transfusion-associated bacterial sepsis. The incidence of transfusion reactions due to bacteria is currently estimated to be between 1:100,000 and 1:1,000,000 units in the case of packed red blood cells and between 1:900 and 1:100,000 units in the case of platelet concentrates. For autologous transfusion, only isolated case reports are available which do not permit a quantitative risk assessment. At present, no reliable data on the risk of morbidity and mortality due to transfusion-associated bacterial infection are available for Germany. Since platelet concentrates, stored at room temperature, provide more favorable conditions for bacterial growth, these blood components are thought to bear a considerably greater risk of bacterial contamination than red blood cells. The rate of contamination of platelet concentrates is cited to be between 0.02 and 1.2%, depending on the production and bacterial culture techniques used, whereas the rate for packed red blood cells is between 0.1 and 0.2%. Risk reduction strategies include careful selection of blood donors, optimization of donation and production techniques, and detection of bacteria in samples of blood components prior to transfusion. Also important for patient safety are quality assurance measures in the preparation for transfusion, patient monitoring, and investigation of transfusion reactions.
Characterizations of sn-metrizable spaces
Authors: Ge Ying
Published: May 2006

We give some characterizations of sn-metrizable spaces. We prove that a space is an sn-metrizable space if and only if it has a locally-finite point-star sn-network. As an application of the result, a space is an sn-metrizable space if and only if it is a sequentially quotient, ? (compact), ?-image of a metric space.
Cover Picture: Macromol. Chem. Phys. 10/2006
Authors: Ding Liming , Bo Zhishan , Chu Qinghui , Li Jing , Dai Liming , Pang Yi , Karasz Frank E. , Durstock Michael F.
Published: May 2006

Cover: The photophysical properties of novel hyperbranched polyfluorenes show a strong dependence on the 1,3,5‐substituted benzene crosspoint density. With increasing crosspoint density the LED color changed from green to violet. Further details can be found in the Full Paper by L. Ding,* Z. Bo, Q. Chu, J. Li, L. Dai, Y. Pang, F. E. Karasz, and M. F. Durstock on page 870.
Front Cover: Macromol. Rapid Commun. 10/2006
Authors: Cheng Fan , Zhang Guang‐Wei , Lu Xiao‐Mei , Huang Yan‐Qin , Chen Yi , Zhou Ying , Fan Qu‐Li , Huang Wei
Published: May 2006

Front Cover: Water‐soluble cationic ammonium‐functionalized PPV possessing photoluminescence with high quantum efficiency interact with an anionic iron‐sulfur protein rubredoxin by attractive Coulomb interaction. Such polymer‐based biosensor exhibits high sensitivity and promising application in biodetection. Further details can be found in the article by F. Cheng, G.‐W. Zhang, X.‐M. Lu, Y.‐Q. Huang, Y. Chen, Y. Zhou, Q.‐L. Fan,* and W. Huang* on page 799.
Poly(ethylene oxide)‐ and poly (acrylamide)‐based water‐soluble associative polymers: synthesis, characterisation, properties in solution
Authors: Grassl Bruno , Billon Laurent , Borisov Oleg , François Jeanne
Published: May 2006

The association behaviour of hydrophobically modified water‐soluble polymers in aqueous solutions and its manifestation in the rheological properties are discussed. In particular, solutions of (i) end‐hydrophobically modified poly(ethylene oxide) and (ii) poly(acrylamide) with grafted hydrophobic side‐chains are considered. We demonstrate that balance between intra‐ and inter‐molecular aggregation and, as a result, rheological behaviour in the solution depend both on polymer architecture and strength of hydrophobic interactions which can be tuned by variation in, e.g., salinity or temperature. Copyright © 2006 Society of Chemical Industry
Quantum phenomena via complex measure: Holomorphic extension
Authors: Srinivasan S.K.
Published: May 2006

The complex measure theoretic approach proposed earlier is reviewed and a general version of density matrix as well as conditional density matrix is introduced. The holomorphic extension of the complex measure density (CMD) is identified to be the Wigner distribution function of the conventional quantum mechanical theory. A variety of situations in quantum optical phenomena are discussed within such a holomorphic complex measure theoretic framework. A model of a quantum oscillator in interaction with a bath is analyzed and explicit solution for the CMD of the coordinate as well as the Wigner distribution function is obtained. A brief discussion on the assignment of probability to path history of the test oscillator is provided.
New core configurations of the c‐edge dislocation in wurtzite GaN
Authors: Belabbas I. , Chen J. , Akli Belkhir M. , Ruterana P. , Nouet G.
Published: May 2006

In the framework of empirical potentials (Modified Stillinger‐Weber), we modelled and studied the energy and the core structure of the c‐edge basal dislocation in wurtzite GaN. Further to the core configurations already known, we report two new ones without wrong bonds. Our calculations show that the configurations containing wrong bonds are the most energetically favourable in both glide and shuffle sets. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Freestanding two inch c‐plane GaN layers grown on (100) γ‐lithium aluminium oxide by hydride vapour phase epitaxy
Authors: Richter E. , Hennig Ch. , Zeimer U. , Weyers M. , Tränkle G. , Reiche P. , Ganschow S. , Uecker R. , Peters K.
Published: May 2006

(100) γ‐lithium aluminium oxide substrates of two inch diameter were fabricated from crystals grown by the Czochralski technique. Onto these substrates c‐plane GaN with a thickness of about 200 µm has been grown by hydride vapour phase epitaxy in a horizontal AIX HVPE reactor. The GaN layer spontaneously separates from the bottom lithium aluminium oxide substrate during the cool‐down resulting in complete freestanding 2 inch GaN wafers. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of structural defects in (11$ \bar 2 $0) GaN films grown on (1$ \bar 1 $02) sapphire substrates
Authors: Vennéguès P. , Mathal F. , Bougrioua Z.
Published: May 2006

The microstructure of (11‐20) GaN films grown on (1‐102) sapphire substrates is studied by transmission electron microscopy. The predominant defects emerging at the surface of a 1‐2 μm thick layers are basal stacking faults of I1 type (1/6<20‐23> displacement vector). These defects are either terminated in the films by partial dislocations with a 1/6<20‐23> Burgers vector or are connected to another basal stacking fault by a prismatic stacking fault with a 1/2<10‐11> displacement vector. All the stacking faults, originate from the interfacial region. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Information systems success in free and open source software development: theory and measures
Authors: Crowston Kevin , Howison James , Annabi Hala
Published: May 2006

Information systems success is one of the most widely used dependent variables in information systems (IS) research, but research on free/libre and open source software (FLOSS) often fails to appropriately conceptualize this important concept. In this article, we reconsider what success means within a FLOSS context. We first review existing models of IS success and success variables used in FLOSS research and assess them for their usefulness, practicality and fit to the FLOSS context. Then, drawing on a theoretical model of group effectiveness in the FLOSS development process, as well as an on‐line discussion with developers, we present additional concepts that are central to an appropriate understanding of success for FLOSS.

In order to examine the practicality and validity of this conceptual scheme, the second half of our article presents an empirical study that demonstrates operationalizations of the chosen measures and assesses their internal validity. We use data from SourceForge to measure the project's effectiveness in team building, the speed of the project at responding to bug reports and the project's popularity. We conclude by discussing the implications of this study for our proposed extension of IS success in the context of FLOSS development and highlight future directions for research. Copyright © 2006 John Wiley & Sons, Ltd.
Glycogen storage diseases in animals and their potential value as models of human disease
Authors: Walvoort H. C.
Published: May 2006

Glycogen storage diseases (GSD) are inborn errors of glycogen metabolism. Of the eight human GSD types in which the enzymatic deficiency has been identified, spontaneous animal counterparts have been reported for GSD I (glucose‐6‐phosphatase deficiency) in the mouse, for GSD II (acid α‐glucosidase deficiency) in the dog, in cattle and in the quail, for GSD III (debrancher enzyme deficiency) in the dog and for GSD VIII (phosphorylase kinase deficiency) in the rat and the mouse. Experimentally induced GSD‐like conditions have been described in the rat (Acarbose‐induced GSD II‐like conditions, iodoacetate‐induced symptoms of myophosphorylase (GSD V) and myophosphofructokinase (GSD VII) deficiency) and the chicken (ochratoxin A‐induced symptoms of cyclic AMP‐dependent protein kinase deficiency). Enzymatic defects that are typical of the human GSD types have not been clearly identified in the induced animal conditions. The homology of animal and human GSD types is discussed. It is concluded that clinical, pathogenic and therapeutic studies of GSD may benefit from the use of animal models. For genetic studies of human GSD these models may prove to be of limited value, as the picture of several human GSD types is already obscured by genetic heterogeneity.
Immunofluorescence staining and immunological studies of arylsulphatase a of multiple sulphatase deficiency (MSD) and metachromatic leukodystrophy (MLD) fibroblasts
Authors: Tanaka A. , Higami S. , Isshiki G. , Matsumoto T. , Furusawa M.
Published: May 2006

Multiple sulphatase deficiency (MSD) and metachromatic leukodystrophy (MLD) are both characterized by a deficiency of arylsulphatase A (ARS A) activity, although they are inherited as separate autosomal recessive traits. However, it has been found that the immunologically active substance with anti‐ARS A antibody is present in quite normal levels in MLD and in smaller quantities in MSD fibroblasts (Fiddler, 1979).

Indirect immunofluorescence staining with anti‐ARS A antibody displayed a coarse granular and diffuse distribution of ARS A or cross‐reacting material (CRM) in the normal control and MLD fibroblasts, whereas very weak fluorescence staining was observed in MSD fibroblasts proportional to the decrease in the ARS A activity observed in the lysate enzyme assay.

These results suggest that ARS A deficiency in MLD cells is due to an enzymatically deficient ARS A molecule, which is immunologically cross‐reactive with anti‐normal ARS A antibody. ARS A deficiency in MSD cells appears to be due to a reduced amount of normal ARS A.
Restraint‐induced stress ulcer. II. biochemical and ultrastructural studies of gastric mucosa
Authors: Balibrea Jose L. , Merchan Jaime , Gomez Jose , Alemany Jose A. , Aznar Jose , Fariña Juliana , Barreno Pedro G. , Fernandez Jose L. , Prado Josefina
Published: May 2006

The aim of these studies was to evaluate the light and electron microscopic changes of the gastric mucosa of restrained rats, and to determine if there were correlations between structural changes, histidine decarboxylase activity, histamine content, and gastric secretion.

In areas with high‐grade mucosal lesions, signs of functional hyperactivity of the oxyntic and chief cells and cytoplasmic degranulation of the enterochromaffin‐like cells were observed. These changes were not influenced by vagotomy. The hyperactivity of the chief cells was related to a higher proteolytic activity of the gastric juice and to an increased excretion of uropepsinogen (p<0.01). The hyperactivity of the oxyntic cells was not accompanied by an increase in total acidity, which could be explained by hydrogen ion back‐diffusion through a damaged gastric mucosal barrier. The increase in histidine decarboxylase activity (p<0.01) and the decrease of histamine content (p<0.01) in the glandular mucosa of restrained rats, together with the microscopic and ultrastructural observations, suggest that the early microcirculatory changes are due to local alterations in the metabolism of vasoactive amines.
Candida infection in surgical patients
Authors: Solomkin Joseph S. , Simmons Richard L.
Published: May 2006

Candida infections have become a common and serious problem in non‐neutropenic general surgical patients. This paper reviews the etiologic factors, pathogenesis of systemic candidiasis, and the more common syndromes of infection in surgical patients. Prophylactic and systemic therapy is detailed. The most significant factor inCandida infections is depression of host immune function. Significant abnormalities of T‐cells, monocytes, and neutrophils have been described in patients with systemicCandida infection and in patients shown to be at high risk of such infection (burned, malnourished, or septic patients). Systemic infection is a consequence of high density colonization at 1 or more sites. Topical therapy with nystatin, amphotericin B, or the imidazole derivatives is usually effective in terminating local colonization of skin lesions, the gastrointestinal tract, or the bladder. If local colonization is not controlled, the patient may progress to systemic infection. The primary diagnostic difficulty is determining when conversions to systemic infection has occurred. Serologic testing and blood culture techniques appear to be of value only late in the course of infection. For this reason, the assessment of culture results from multiple sites appears to be of value. Treatment is begun with systemic amphotericin if the patient is immunodepressed or has ≥ 3 sites positive forCandida. In nonneutropenic patients, relatively short therapy appears effective. Treatment of endocarditis requires several (4–6) weeks of therapy, and current evidence suggests that early surgery with valve replacement may improve survival.
Surgical infections in drug addicts
Authors: Hau Toni , Kallick Charles A.
Published: May 2006

Infectious complications are responsible for a majority of the medical and surgical hospital admissions and 15% of the deaths of drug addicts. The most common and serious complication is endocarditis, mostly of the right heart, caused by Staphylococci and/or gram‐negative rods. If the endocarditis is caused by the latter group of organisms, early operative intervention with excision of the tricuspid and/or replacement of the mitral and aortic valves is frequently necessary because of poor response to antibiotic treatment. Other complications of generalized sepsis are septic pulmonary emboli, which frequently gives rise to pulmonary abscesses, and splenic abscesses. Infections of the vascular system occur as either suppurative thrombophlebitis or mycotic aneurysms. Soft tissue infections in the form of subcutaneous abscesses, cellulitis, myositis, and necrotizing fasciitis are caused by a mixed flora consisting of gram‐positive and gram‐negative aerobes and anaerobes. The majority of patients with tetanus seen in large cities are drug addicts. Infections of the skeletal system are typically caused bySerratia marcescens orPseudomonas, and present as septic arthritis of the sternoclavicular or sacroiliac joints or osteomyelitis of the spine originating from a disc space infection.
The overwhelming postsplenectomy sepsis problem
Authors: Leonard Arnold S. , Giebink G. Scott , Baesl Thomas J. , Krivit William
Published: May 2006

Postsplenectomy vulnerability to infection is not limited to age or disease process. Postsplenectomy infection is an emergency problem that requires immediate and accurate treatment because death is potential within a few hours of onset. Although the pathogenesis of overwhelming postsplenectomy sepsis is not completely understood, experimental evidence suggests that loss of mechanical filtration is more important than immunologic deficiences resulting from splenectomy. Certainly, a combination of both may be present. While no single measure seems to completely protect against overwhelming postsplenectomy sepsis, experimental evidence suggests that by reducing or minimizing the amount of spleen removed by newer surgical techniques, and by the addition of pneumococcal vaccine and prophylactic penicillin, the incidence of overwhelming sepsis can be reduced. Further evaluation of splenic function is necessary to assess the role of autotransplantation in the prevention of postsplenectomy sepsis (Fig. 1).
Predicting surgical infection before the operation
Authors: Meakins Jonathan L. , Pietsch John B. , Christou Nicolas V. , Maclean Lloyd D.
Published: May 2006

To date, simple skin testing using recall antigens has proven to be the most accurate method of assessing preoperative risk for serious infectious complications. When used in conjunction with measures to control the microorganisms and the environment, evaluation of host defense mechanisms with skin testing can aid in reducing postoperative infectious morbidity and mortality.

There are 3 possible therapeutic approaches to anergic patients. Surgery and specific nonsurgical treatments (restoration of blood volume, red cell mass, antibiotics), total parenteral nutrition, and immunorestoration. The challenge for the future is to develop the criteria that will indicate the most important defects which account for the anergic state in individual patients.
Long‐term effects of bile on the gastric mucosa of the dog
Authors: Cardoso de Oliveira M. , Azevedo Isabel
Published: May 2006

Bile was allowed to act on the gastric mucosa of dogs for periods of time ranging from 60 to 540 days. Then the mucosa was studied by light microscopy and morphometric techniques to determine height of the mucosa, infundibulum and glands, number of mast cells, and number of interepithelial lymphocytes. Marked acute inflammatory lesions and decrease in cellular mucin content were observed mainly in the antral mucosa exposed to bile for up to 130 days. Other changes appearing both in the antrum and fundus of the same dogs included an increase in the number of interepithelial lymphocytes, architectural distortion, and decrease in the height of the mucosa, the infundibulum being the most affected component in the antrum and the glands in the fundus. Positive alkaline phosphatase activity was observed in the antral area up to 130 days. With continuous exposure to bile, the gastric mucosa appeared to undergo adaptation, since all the described alterations gradually disappeared.
Prevention of postoperative deep vein thrombosis in Sweden results of a survey
Authors: Bergqvist David
Published: May 2006

All 236 clinics in Sweden dealing with general, urologic, orthopedic, and gynecologic surgery were sent a questionnaire concerning their policy about prophylaxis against postoperative thromboembolism and 94% replied. Of these, 76% claimed that they use some kind of prophylaxis. Decisive factors for the adoption of routine prophylaxis and prophylactic methods in current use varied among the 4 surgical specialties surveyed. In spite of the evidence that age is the most important single risk factor for thromboembolic complications, only 45% of the clinics considered age to be important. The estimated frequency of prophylaxis among patients undergoing operations was only 19%. Side effects of prophylaxis were reported in 55% of the clinics. Dextran 70 and low‐dose heparin were the most frequently used prophylactic methods.
Contraction and the control of contraction
Authors: Rudolph Ross
Published: May 2006

Wound contraction is a basic mechanism for wound closure that can be lifesaving. Yet, wound contraction can also produce considerable deformity and misery in conditions as diverse as burn scar contracture, cirrhosis, Dupuytren's contracture, and contracture around silicone tissue implants. Current evidence suggests that wound contraction is a cellular function of contractile fibroblasts (myofibroblasts). These cells share the electron microscopic appearance of both fibroblasts and smooth muscle cells. Pharmacologically and immunologically, myofibroblasts have many characteristics of smooth muscle cells. Active wound contraction caused by myofibroblasts can lead to fixed, rigid scar contracture. Contracture associated with poor joint positioning can also occur passively due to collagen reorganization alone, without myofibroblast involvement.

Control of contraction (and contracture) can be achieved theoretically by 3 modes of therapy. Physical means, including range of motion exercises, splinting, and full thickness skin grafting after surgical release, are used currently. Biochemical control of myofibroblast contraction by agents that affect tissue‐cultured fibroblasts has the potential of reducing wound contraction. Inhibition of collagen synthesis, inhibition of cross‐linking, or increased collagenolysis may eventually be clinically useful, and would be of value in controlling both contracture due to active wound contraction, and contracture due to passive positioning.
Management of graft infections following abdominal aortic aneurysm replacement
Authors: Bernhard Victor M.
Published: May 2006

Graft infection following resection of an abdominal aortic aneurysm is a rare but highly lethal complication. It is most commonly associated with aortoenteric fistula or external contamination when graft limbs extend to the groin. Other sources are bowel or urinary tract entry, latent infection in the aneurysm wall, breaks in sterile technique, or bacteremia. Diagnosis should be suspected when a patient with an aortic graft develops unexplained fever, especially with back or abdominal pain, gastrointestinal bleeding of any kind, or metastatic infection to the limbs. Diagnosis is difficult to establish. Endoscopy to demonstrate erosion into the distal duodenum or to rule out other sources of bleeding was useful in all 6 patients in which it was employed. Positive arterial cultures distal to the graft, the finding of bilateral hydronephrosis, and demonstration of periaortic inflammation on gallium scan are highly suggestive. Aortography was helpful in 2 of 6 patients but was useless when negative. Barium contrast x‐ray studies were usually negative (90%) or confusing. Management requires excision of all infected graft material, usually the entire prosthesis. Restoration of limb circulation, usually with axillo femoral bypass, should be done in all patients except those with prior amputation or previous iliac artery or graft occlusion with adequate collaterals. A 35% patient survival rate was achieved in 20 patients with graft infection and aortoenteric fistula. However, when a correct diagnosis was made without delay and appropriate principles of management were instituted, 78% (7 of 9) patients survived and no amputations were required in the 5 patients with intact limbs. Prevention of postaneurysmectomy graft infection requires meticulous aseptic technique, effective graft coverage and separation from loops of bowel with viable tissue, and the use of prophylactic systemic and local antibiotics.
Small artery reconstruction with a new vascular prosthesis
Authors: Raithel Dieter , Groitl Heinrich
Published: May 2006

In the Surgical Department of the University of Erlangen, 307 reconstructions in all areas of the arterial tree were performed with PTFE (GORE‐TEX®) grafts, of which 188 were performed in the femoral‐popliteal and femoral‐crural areas. Femoral‐popliteal bypass grafts above the knee joint remained patent in 93% of the patients during an average follow‐up time of 6.7 months. Below the knee joint, the patency rate was 85% during an average follow‐up time of 5.6 months. In the proximal aorta, aorta‐renal, and aorta‐femoral areas, long‐term results with the PTFE graft have been excellent.
Transapical left ventricular bypass with local heparinization for prolonged circulatory support
Authors: Taguchi Kazumi , Murashita Junji , Nakagaki Mitsuru , Mochizuki Takaaki
Published: May 2006

An avcothanized vinyl sheet consisting of a Pall filter®, 2 pressure monitoring lines, 2 heparinization lines, and a roller pump was used for transapical left ventricular bypass in 36 calves and 11 patients. Blood was returned to the abdominal or ascending aorta or carotid artery. Prolonged left ventricular flow unloading was carried out. All 31 calves that underwent left ventricular bypass and 5 calves that underwent biventricular bypass survived the scheduled period of bypass of up to 7 weeks except for 2 calves that died of accidental air embolism and 2 that were deliberately sacrificed due to infection. Local heparinization for 6 days followed by oral anticoagulation to maintain the prothrombin time at 150–200% of normal were effective in keeping the animals from bleeding and preventing thromboembolism. Eleven critically ill patients with severe heart disease were supported with left or biventricular bypass for periods of up to 172 hours. Four patients ultimately recovered, and 3 others were successfully weaned from bypass and expired 1–4 months later.
Gallstone ileus: An analysis of 20 patients
Authors: Heuman Rolf , Sjödahl Rune , Wetterfors Jarl
Published: May 2006

An analysis of 20 patients with gallstone ileus treated at the University Hospital in Linköping during a 10‐year period is presented. The patients had a median age of 75 years and 70% were women. The symptomatology was usually vague and consisted of diffuse abdominal pain, often accompanied by vomiting. The delay before admission to the hospital averaged 4 days. Radiography with both plain abdominal x‐rays and a barium meal showed mechanical intestinal obstruction in all but 1 patient and gallstone ileus was diagnosed before laparotomy in 60% of patients. Enterolithotomy was performed in all patients but there was no surgery on the gallbladder and/or the fistula. The frequency of postoperative wound infection was 25%. There was only 1 death, a mortality rate of 5%. It is our opinion that the low mortality was due to early diagnoses, careful preoperative preparation, an operative procedure aiming only at relief of the obstruction, and improved anesthesia and prophylactive short‐term antibiotics. The only indication for an elective cholecystectomy is persistent symptoms of gallbladder disease.
Experimental studies of ischemic enterocolitis
Authors: Mishima Yoshio , Horie Yoshiaki
Published: May 2006

Occlusion of the minute vessels of the bowel produces hemorrhage, ulceration, and necrosis of the bowel wall. To clarify the pathophysiology of the ischemic lesions caused by minute vessel occlusion, a microbarium suspension was injected into the mesenteric vessels of mongrel dogs. The pathological process in the bowel wall was parallel to the degree and extent of occlusion. The changes observed in these experimental studies were similar to those encountered in patients with ischemic enterocolitis. From our clinical and experimental analyses, the bowel lesions caused by minute vessel occlusion were classified into 3 categories according to the layer of the bowel wall involved, namely (a) mucosal, (b) submucosal and muscular, and (c) all layers of the bowel wall. In the lesions confined to the mucosal layer, the pathological processes were transient and reversible, and special treatment was not necessary since spontaneous recovery could be expected in almost all cases without any functional disturbance. When the ischemic changes involved the submucosal layer beyond the base of the crypts, ulceration almost always developed and was followed by a high incidence of stenosis due to scar formation. In this type of lesion, surgical treatment is required if stenosis persists after healing of the intestinal ischemic lesions. When the ischemic processes extended through all layers of the bowel wall, characteristic endoscopic findings were observed even in the early stages. Because of the high mortality rate, immediate surgical intervention is mandatory.
A comparison of sites suitable for the seedling establishment of two co‐occurring species, Swintonia glauca and Stemonurus scorpioides, in a tropical peat swamp forest
Authors: Shimamura Tetsuya , Momose Kuniyasu , Kobayashi Shigeo
Published: May 2006

Spatial and temporal ground‐surface dynamics are major factors that affect regeneration and species coexistence in tropical peat swamp forests. We studied the seedling survivorship and morphological features of two tree species that play important roles in maintaining the ground‐surface dynamics of a peat swamp forest in Sumatra. Large Swintonia glauca trees form mounds, whereas large Stemonurus scorpioides trees occupy non‐mounds. We monitored the demography of naturally dispersed Swintonia and Stemonurus seedlings that germinated in 2000. Survivorship of Swintonia seedlings was high under conditions of late germination, high‐light environment, and elevated ground surface, and was negatively affected by distance to the nearest conspecific adult. Survivorship of Stemonurus was high under conditions of early germination and high conspecific seedling density, and was also negatively affected by distance to the nearest conspecific adult. The allometric features of Stemonurus seedlings indicated characteristics of stress tolerance, that is, low growth rate and thick, porous roots. Stemonurus, which has large wingless seeds, regenerated in non‐mounds around the parental trees, while winged Swintonia seeds dispersed farther from the parent and established in patchily distributed gaps and mounds. Thus, Swintonia seedlings can survive on non‐mound sites within gaps and possibly create mounds, while Stemonurus seedlings tend to maintain non‐mounds around the parental trees.
Temporal relationship between MMP production and angiogenic process in HUVECs
Authors: Kiran M.S. , Kumar V.B. Sameer , Viji R.I. , Sudhakaran P.R.
Published: May 2006

Alterations in both cell—cell and cell—matrix interactions are associated with the activation of endothelial cells that initiate angiogenesis. Cell—matrix interactions are affected by changes in both cell surface receptors for matrix proteins and the composition of ECM. One of the molecular mechanisms involved in changes in these components is the action of neutral proteinases, particularly matrix metalloproteinases. To understand the involvement of MMPs in angiogenic processes, the in vitro model of human umbilical vein endothelial cells in culture was used. Zymography and ELISA showed that, as cell—cell contact and network‐like structures were formed, there was down regulation of MMP‐2 and MMP‐9 associated with high levels of their endogenous inhibitors TIMP‐1 and TIMP‐2. On treatment with aspirin, which inhibited the cell—cell contact and network‐like structure formation, there was no down regulation of MMPs and cells continued to produce MMP‐2 and MMP‐9. These results indicate a temporal relationship between MMP‐2 and MMP‐9 production by endothelial cells and the onset of angiogenic event.
Variscan veins: record of fluid circulation and Variscan tectonothermal events in Upper Palaeozoic limestones of the Moravian Karst, Czech Republic
Authors: SLOBODNÍK M. , MUCHEZ PH. , KRÁL J. , KEPPENS E.
Published: May 2006

Numerous Variscan syntectonic calcite veins cross-cut Palaeozoic rocks in the Moravian Karst. A structural, petrographic and stable isotopic analysis of the calcite veins and a microthermometric study of fluid inclusions in these vein cements have been carried out to determine the origin of the Variscan fluids and their migration during burial and deformation. The isotopic parameters of white (older, more deformed) and rose (younger) calcites are: 87Sr/86Sr is between 0.7078 and 0.7082 (white) and 0.7086 (rose), δ18O is between +17.7 and +26.1 (white) and between +14.8 and +20.7 ‰ SMOW (rose), δ13C ranges from +0.1 to +2.5 (white) and from −0.3 to +1.6 ‰ V-PDB (rose). The isotopic signatures point to precipitation in an older fluid system buffered by the host rock (white calcites) and to an open, younger fluid-dominated system (rose calcites). Parent fluids (H2O–NaCl system) had salinities between 0.35 and 17.25 eq. wt % NaCl. The pressure-corrected and confined homogenization temperatures suggest formation of the calcite veins from a fluid with a temperature between 120 and 170 °C, a pressure of 300–880 bar at a depth between 2.1 and 3.2 km. The fluids were most likely confined to a particular sedimentary bed as a bed-scale fluid migration (white older calcite veins) or, later, to a pile of Palaeozoic sediments as a stratigraphically restricted fluid flow (rose younger calcite veins). The low temperatures and pressures during precipitation of calcites, which took place close to a peak of burial/deformation, confirm the distal position of the Moravian Karst region within the Variscan orogen.
Blockade of substance P (neurokinin 1) receptors enhances extracellular serotonin when combined with a selective serotonin reuptake inhibitor: an in vivo microdialysis study in mice
Authors: Guiard Bruno P. , Przybylski Cédric , Guilloux Jean‐Philippe , Seif Isabelle , Froger Nicolas , De Felipe Carmen , Hunt Stephen P. , Lanfumey Laurence , Gardier Alain M.
Published: May 2006

Substance P antagonists of the neurokinin‐1 receptor type (NK1) are gaining growing interest as new antidepressant therapies. It has been postulated that these drugs exert this putative therapeutic effect without direct interactions with serotonin (5‐HT) neurones. Our recent microdialysis experiment performed in NK1 receptor knockout mice suggested evidence of changes in 5‐HT neuronal function (Froger et al. 2001). The aim of the present study was to evaluate the effects of coadministration of the selective 5‐HT reuptake inhibitor (SSRI) paroxetine with a NK1 receptor antagonist (GR205171 or L733060), given either intraperitoneally (i.p.) or locally into the dorsal raphe nucleus, on extracellular levels of 5‐HT ([5‐HT]ext) in the frontal cortex and the dorsal raphe nucleus using in vivo microdialysis in awake, freely moving mice. The systemic or intraraphe administration of a NK1 receptor antagonist did not change basal cortical [5‐HT]ext in mice. A single systemic dose of paroxetine (4 mg/kg; i.p.) resulted in a statistically significant increase in [5‐HT]ext with a larger extent in the dorsal raphe nucleus (+ 138% over basal AUC values), than in the frontal cortex (+ 52% over basal AUC values). Co‐administration of paroxetine (4 mg/kg; i.p.) with the NK1 receptor antagonists, GR205171 (30 mg/kg; i.p.) or L733060 (40 mg/kg; i.p.), potentiated the effects of paroxetine on cortical [5‐HT]ext in wild‐type mice, whereas GR205171 (30 mg/kg; i.p.) had no effect on paroxetine‐induced increase in cortical [5‐HT]ext in NK1 receptor knock‐out mice. When GR205171 (300 µmol/L) was perfused by ‘reverse microdialysis’ into the dorsal raphe nucleus, it potentiated the effects of paroxetine on cortical [5‐HT]ext, and inhibited paroxetine‐induced increase in [5‐HT]ext in the dorsal raphe nucleus. Finally, in mice whose 5‐HT transporters were first blocked by a local perfusion of 1 µmol/L of citalopram into the frontal cortex, a single dose of paroxetine (4 mg/kg i.p.) decreased cortical 5‐HT release, and GR205171 (30 mg/kg i.p.) reversed this effect. The present findings suggest that NK1 receptor antagonists, when combined with a SSRI, augment 5‐HT release by modulating substance P/5–HT interactions in the dorsal raphe nucleus.
Structure of low-lying electronic states of NdO: Quantum chemical calculations
Authors: Allouche A. R. , Aubert-Frécon M. , Umanskiy S. Ya.
Published: May 2006

Low-lying states of the NdO molecule have been predicted from quantum mechanical complete active-space self-consistent field/multireference configuration interaction/spin-orbit calculations. 54 states labeled through the quantum number Ω(+∕−) have been determined in the excitation energy range of ∼1eV. For each state molecular constants Te, Tv, ωe, ΔGv, Re, Be, and Bv have been calculated. All these states display nearly identical principal structural characteristics: equilibrium internuclear distance and vibrational frequency. Calculated values of Tv, ΔGv, and Bv agree satisfactorily with experimental values available for nine electronic states among the 54 considered. The feasibility of a statistical representation of the low-lying states of NdO is considered.
The geometric, electronic, and magnetic properties of Ag5X+ (X=Sc, Ti, V, Cr, Mn, Fe, Co, and Ni) clusters
Authors: Janssens Ewald , Hou Xin Juan , Nguyen Minh Tho , Lievens Peter
Published: May 2006

Density functional theory calculations are performed on small cationic transition metal doped silver clusters, Ag5X+ (X=Sc, Ti, V, Cr, Mn, Fe, Co, and Ni) using the B3LYP and BP86 functionals. Several two-dimensional and three-dimensional isomers with the dopant at a high coordinated site are found to be close in energy. The relative energy of the isomers is checked with CCSD(T). The interaction between the dopant 3d electrons and the host is discussed by considering the density of states and the shape of the molecular orbitals. A large local spin magnetic moment on the dopant atom is predicted.
Direct calculation of solid-vapor coexistence points by thermodynamic integration: Application to single component and binary systems
Authors: Apte Pankaj A. , Kusaka Isamu
Published: May 2006

We present a new thermodynamic integration method that directly connects the vapor and solid phases by a reversible path. The thermodynamic integration in the isothermal-isobaric ensemble yields the Gibbs free energy difference between the two phases, from which the sublimation temperature can be easily calculated. The method extends to the binary mixture without any modification to the integration path simply by employing the isothermal-isobaric semigrand ensemble. The thermodynamic integration, in this case, yields the chemical potential difference between the solid and vapor phases for one of the components, from which the binary sublimation temperature can be calculated. The coexistence temperatures predicted by our method agree well with those in the literature for single component and binary Lennard-Jones systems.
Fragmentation dynamics of argon clusters (Arn, n=2 to 11) following electron-impact ionization: Modeling and comparison with experiment
Authors: Bonhommeau David , Halberstadt Nadine , Viel Alexandra
Published: May 2006

The fragmentation dynamics of argon clusters ionized by electron impact is investigated for initial cluster sizes up to n=11 atoms. The dynamics of the argon atoms is modeled using a mixed quantum-classical method in which the nuclei are treated classically and the transitions between electronic states quantum mechanically. The potential-energy surfaces are derived from a diatomics-in-molecules model with the addition of the induced dipole-induced dipole and spin-orbit interactions. The results show extensive and fast fragmentation. The dimer is the most abundant ionic fragment, with a proportion increasing from 66% for n=2 to a maximum of 95% for n=6 and then decreasing down to 67% for n=11. The next abundant fragment is the monomer for n<7 and the trimer otherwise. The parent ion dissociation lifetimes are all in the range of 1ps. Long-lived trajectories appear for initial cluster sizes of seven and higher, and favor the formation of the larger fragments (trimers and tetramers). Our results show quantitative agreement with available experimental results concerning the extensive character of the fragmentation: Ar+ and Ar2+ are the only ionic fragments for sizes up to five atoms; their overall proportion is in quantitative agreement for all the studied sizes; Ar2+ is the main fragment for all sizes; stable Ar3+ fragments only appear for n⩾5, and their proportion increases smoothly with cluster size from there. However, the individual ionic monomer and dimer fragment proportions differ. The experimental ones exhibit oscillations with initial cluster size, with a slight tendency to decrease on average for the monomer. In contrast our results show a monotonic, systematic evolution, similar to what was found in our earlier studies on neon and krypton clusters. Several hypotheses are discussed in order to find the origin of this discrepancy. Finally, the metastable II(1∕2)u and II(1∕2)g states of Ar2+ are found to decay with a lifetime of 3.5 and 0.1ps, respectively, due to spin-orbit coupling. The difference with the commonly accepted microsecond range value for rare-gas dimer ions could originate from the role of autoionizing states in the formation of the parent ions.
Experimental and theoretical studies of Λ doublings and permanent electric dipoles in the low-lying Π1 states of NaCs
Authors: Zaharova J. , Nikolayeva O. , Tamanis M. , Auzinsh M. , Ferber R. , Zaitsevskii A. , Pazyuk E. A. , Stolyarov A. V.
Published: May 2006

We present experimental data on the electric permanent dipole moments d(υ′,J′) and Λ splittings (q factors) in the quasidegenerate (3)Πe∕f1 state of the NaCs molecule over a wide range of the vibrational (υ′) and rotational (J′) quantum numbers by using the combination of dc Stark mixing and electric radio frequency-optical double resonance methods. Within the experimental (3)Π1 state υ′ ranged from υ′=0 to 34, q values exhibited a pronounced decrease from 7.91×10−6to0.47×10−6cm−1, while ∣d∣ values varied between 8.0 and 5.0D. Experimental evaluation yielded small d values about 1D for D(2)Π1 state υ′<3 levels. The experiment is supported by ab initio electronic structure calculations performed for the (1–3)Π1 states of NaCs by means of the many-body multipartitioning perturbation theory of potential energy curves, permanent dipole, and angular coupling matrix elements for the lowest singlet states. The predicted d values reproduce their experimental counterparts within the measurement errors while theoretical q factors reproduce the measured υ′ dependence being, however, systematically overestimated by ca. 1×10−6cm−1. The present NaCs data are compared with those of the NaK and NaRb molecules.
Interchange and infernal fishbone modes in plasmas with tangentially injected beams
Authors: Kolesnichenko Ya. I. , Marchenko V. S. , White R. B.
Published: May 2006

New energetic particle mode instabilities of fishbone type are predicted. The considered instabilities are driven by circulating energetic ions. They can arise in plasmas of tokamaks and spherical tori with weak magnetic shear in the wide core region and strong shear at the periphery, provided that the central safety factor is close to the ratio m∕n, where m and n are the poloidal mode number and toroidal mode number, respectively. The instability with m=n=1 has a mainly interchange-like radial structure, whereas the radial structure of instabilities with m∕n>1 is mainly similar to that of the infernal magnetohydrodynamics (MHD) mode; the differences between the fishbone mode structures and MHD mode structures are considerable only in the vicinity of the local Alfvén resonance.
Time-dependent plasma viscosity in asymmetric toroidal plasmas
Authors: Shaing K. C.
Published: May 2006

Time-dependent viscosity for asymmetric toroidal plasmas in the low collisional frequency regimes is calculated. Because time-dependent plasma viscosity accurately predicts the flow-damping rate, the results can be used in modeling the momentum relaxation, including modeling the radial electric field of the zonal flow.
Elastic and related transport cross sections for protons scattering from the noble gases He, Ne, Ar, Kr, and Xe
Authors: Krstić P. S. , Schultz D. R.
Published: May 2006

Using a fully quantum mechanical treatment, cross sections have been calculated over a wide range of center-of-mass collision energies (0.1–10 000eV) for the elastic scattering of protons from noble gas atoms He, Ne, Ar, Kr, and Xe. In addition, the momentum transfer and viscosity cross sections, relevant to transport modeling, have been computed along with results of the classical trajectory Monte Carlo method. The comparison of the results from two methods of calculation enables improved insight into the accuracy of the cross sections obtained within various energy ranges. Scaling relations of fusion energy research interest are given allowing the data to be applied for D+ and T+ impact. Also, owing to improvements and extensions of the methods utilized here, we describe updated elastic and transport cross sections for H++C in the Appendix. All of the data calculated here are explicitly tabulated on the worldwide web for convenient use in plasma modeling.
Large internal quantum efficiency of In-free UV-emitting GaN∕AlGaN quantum-well structures
Authors: Fuhrmann D. , Retzlaff T. , Rossow U. , Bremers H. , Hangleiter A. , Ade G. , Hinze P.
Published: May 2006

We have achieved dramatic improvement of the internal quantum efficiency (IQE) for ultraviolet-emitting GaN∕AlGaN quantum-well (QW) structures. Despite a defect density of a few 109cm−2 and the use of an In-free QW we achieve best values for the IQE at room temperature of 26%. Under strong nonresonant excitation, the IQE even increases to 38%. We observe a weak dependence of the IQE on excitation power for our structures. This indicates that similar mechanisms as for GaInN-based light emitters are present.
Field-emission-induced growth of nanowire between electrodes
Authors: Yeong K. S. , Law J. B. K. , Thong J. T. L.
Published: May 2006

We demonstrate the growth of a tungsten nanowire between two microtip electrodes by the field-emission-induced growth process. A nanowire is grown from the cathode towards the opposing biased anode in a quasicontinuous manner. In order to study the nanowire growth process, the wire is grown in a stepwise manner until it bridges the cathode and the anode. The growth of the nanowire across the cathode-anode gap falls into four different regimes of initiation, steady growth, close-gap growth, and finally bridging of electrodes. The profile of the field-enhancement factor of the nanowire field emitter during growth matches the results from electrostatic modeling.