bluuebunny/crossref_metadata_2025 huggingface dataset:
TiC‐Based Cermet Coatings: Advanced Wear Performance by Nanocrystalline Microstructure
Authors: Qi X. , Aust E. , Eigen N. , Gärtner F. , Klassen T. , Bormann R.
Published: May 2006

This paper highlights the influence of a refined microstructure on the wear behaviour of cermets by comparing TiC‐Ni based, VPS‐sprayed microcrystalline and nanocrystalline cermet coatings. The coatings are subjected to two‐body and three‐body abrasive wear at different loads. Fracture behaviour as well as mass loss and surface quality after the wear tests are evaluated. Although at low wear loads, the refined microstructure leads to a higher mass loss, at high loads the wear resistance of the nanocrystalline coating is superior. This behaviour is strongly related to a significantly higher toughness of the nanocrystalline coating. Independent of the wear load, the nanocrystalline microstructure leads to less surface roughness after wear.
Structural Integrity Assessment of Thin‐Walled Structures
Authors: Brocks W. , Schwalbe K.‐H. , Zerbst U.
Published: May 2006

As part of the concept of damage tolerant design, methods for the analytical and numerical simulation of ductile crack extension in thin‐walled structures are presented and discussed. They comprise the application of an analytical flaw assessment procedure as well as finite element analyses based on the crack tip opening displacement (CTOD), δ5, and finite element simulations of crack extension based on the crack tip opening angle (CTOA), a cohesive zone model and a ductile damage model. All these methods are or will become part of the GKSS Structural Integrity Assessment Method (SIAM), which also provides test procedures for the experimental determination of the required material parameters.
Estimating fog deposition at a Puerto Rican elfin cloud forest site: comparison of the water budget and eddy covariance methods
Authors: Holwerda F. , Burkard R. , Eugster W. , Scatena F. N. , Meesters A. G. C. A. , Bruijnzeel L. A.
Published: May 2006

The deposition of fog to a wind‐exposed 3 m tall Puerto Rican cloud forest at 1010 m elevation was studied using the water budget and eddy covariance methods. Fog deposition was calculated from the water budget as throughfall plus stemflow plus interception loss minus rainfall corrected for wind‐induced loss and effect of slope. The eddy covariance method was used to calculate the turbulent liquid cloud water flux from instantaneous turbulent deviations of the surface‐normal wind component and cloud liquid water content as measured at 4 m above the forest canopy. Fog deposition rates according to the water budget under rain‐free conditions (0·11 ± 0·05 mm h−1) and rainy conditions (0·24 ± 0·13 mm h−1) were about three to six times the eddy‐covariance‐based estimate (0·04 ± 0·002 mm h−1). Under rain‐free conditions, water‐budget‐based fog deposition rates were positively correlated with horizontal fluxes of liquid cloud water (as calculated from wind speed and liquid water content data). Under rainy conditions, the correlation became very poor, presumably because of errors in the corrected rainfall amounts and very high spatial variability in throughfall. It was demonstrated that the turbulent liquid cloud water fluxes as measured at 4 m above the forest could be only ∼40% of the fluxes at the canopy level itself due to condensation of moisture in air moving upslope. Other factors, which may have contributed to the discrepancy in results obtained with the two methods, were related to effects of footprint mismatch and methodological problems with rainfall measurements under the prevailing windy conditions. Best estimates of annual fog deposition amounted to ∼770 mm year−1 for the summit cloud forest just below the ridge top (according to the water budget method) and ∼785 mm year−1 for the cloud forest on the lower windward slope (using the eddy‐covariance‐based deposition rate corrected for estimated vertical flux divergence). Copyright © 2006 John Wiley & Sons, Ltd.
Capillary gas‐chromatographic determination of spermidine in hair lotion
Authors: Gambaro Veniero , Casagni Eleonora , Dell'Acqua Lucia , Valenti Mauro , Visconti Giacomo L.
Published: May 2006

Biogenic polyamines, such as spermidine (SPD, NH2–(CH2)4–NH–(CH2)3–NH2), are ubiquitous polycationic molecules which play a definitive role in many biological processes such as nucleic acid metabolism, protein synthesis, and cell growth. SPD is commonly used as an ingredient in hair lotions, because it seems to promote hair growth. This work describes a capillary GC method for quantitative determination of SPD in hair lotions using 1,6‐diaminohexane as internal standard, a methyl silicone capillary column, and a flame ionisation detector. Aliquots of hair lotion were treated with an alkaline aqueous solution and internal standard was added. The emulsion was extracted with diethyl ether containing ethyl chloroformate. Ether extracts, evaporated to dryness and reconstituted in ethyl acetate, were analysed by capillary GC with flame ionisation detection. Validation took into account the specificity, linearity, precision, and accuracy of the analytical method: these parameters were valid for the quantitative determination of SPD in hair lotion.
Thermal dissociation behavior of copolymers bearing hemiacetal ester moieties and their reactions with epoxides
Authors: Komatsu Hiroyuki , Hino Tetsuo , Endo Takeshi
Published: May 2006

Copolymers from 1‐propoxyethyl methacrylate and various vinyl monomers such as n‐butyl methacrylate and styrene were synthesized, and the thermal dissociation reaction of the copolymers containing the hemiacetal ester structure was examined. The copolymers, having the ability of thermal dissociation, could control the thermal dissociation temperature because of the bulkiness and flexibility of the vinyl comonomers, the copolymer compositions, and so on. Furthermore, the possibility of control of the initiation in thermally latent addition with epoxides in the case of copolymers was also studied. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3966–3977, 2006
Sorption–desorption of flucarbazone and propoxycarbazone and their benzenesulfonamide and triazolinone metabolites in two soils
Authors: Koskinen William C , Calderón María Jesus , Rice Pamela J , Cornejo Juan
Published: May 2006

Sorption–desorption interactions of pesticides with soil determine the availability of pesticides in soil for transport, plant uptake and microbial degradation. These interactions are affected by the physical and chemical properties of the pesticide and soil and, for some pesticides, their residence time in the soil. While sorption–desorption of many herbicides has been characterised, very little work in this area has been done on herbicide metabolites. The objective of this study was to characterise sorption–desorption of two sulfonylaminocarbonyltriazolinone herbicides, flucarbazone and propoxycarbazone, and their benzenesulfonamide and triazolinone metabolites in two soils with different physical and chemical properties.Kfvalues for all four chemicals were greater in clay loam soil, which had higher organic carbon and clay contents than loamy sand.Kf−ocranged from 29 to 119 for the herbicides and from 42 to 84 for the metabolites. Desorption was hysteretic in every case. Lower desorption in the more sorptive system might indicate that hysteresis can be attributed to irreversible binding of the molecules to soil surfaces. These data show the importance of characterisation of both sorption and desorption of herbicide residues in soil, particularly in the case of prediction of herbicide residue transport. In this case, potential transport of sulfonylaminocarbonyltriazolinone herbicide metabolites would be overpredicted if parent chemical soil sorption values were used to predict transport. Copyright © 2006 Society of Chemical Industry
Cytochrome b gene structure and consequences for resistance to Qo inhibitor fungicides in plant pathogens
Authors: Grasso Valeria , Palermo Simona , Sierotzki Helge , Garibaldi Angelo , Gisi Ulrich
Published: May 2006

The cytochrome b (cyt b) gene structure was characterized for different agronomically important plant pathogens, such as Puccinia recondita f sp tritici (Erikss) CO Johnston, P graminis f sp tritici Erikss and Hennings, P striiformis f sp tritici Erikss, P coronata f sp avenae P Syd & Syd, P hordei GH Otth, P recondita f sp secalis Roberge, P sorghi Schwein, P horiana Henn, Uromyces appendiculatus (Pers) Unger, Phakopsora pachyrhizi Syd & P Syd, Hemileia vastatrix Berk & Broome, Alternaria solani Sorauer, A alternata (Fr) Keissl and Plasmopara viticola (Berk & Curt) Berlese & de Toni. The sequenced fragment included the two hot spot regions in which mutations conferring resistance to QoI fungicides may occur. The cyt b gene structure of these pathogens was compared with that of other species from public databases, including the strobilurin‐producing fungus Mycena galopoda (Pers) P Kumm, Saccharomyces cerevisiae Meyer ex Hansen, Venturia inaequalis (Cooke) Winter and Mycosphaerella fijiensis Morelet. In all rust species, as well as in A solani, resistance to QoI fungicides caused by the mutation G143A has never been reported. A type I intron was observed directly after the codon for glycine at position 143 in these species. This intron was absent in pathogens such as A alternata, Blumeria graminis (DC) Speer, Pyricularia grisea Sacc, Mycosphaerella graminicola (Fuckel) J Schröt, M fijiensis, V inaequalis and P viticola, in which resistance to QoI fungicides has occurred and the glycine is replaced by alanine at position 143 in the resistant genotype. The present authors predict that a nucleotide substitution in codon 143 would prevent splicing of the intron, leading to a deficient cytochrome b, which is lethal. As a consequence, the evolution of resistance to QoI fungicides based on G143A is not likely to evolve in pathogens carrying an intron directly after this codon. Copyright © 2006 Society of Chemical Industry
Structural and optical characterization of AlyInxGa1–x –yN quantum dots
Authors: Pérez‐Solórzano V. , Gröning A. , Schweizer H. , Jetter M.
Published: May 2006

Aly Inx Ga1–x –y N quantum dots have been grown by MOVPE on (0001) sapphire substrates. We investigated the dependence of the self‐assembled quantum dot density and height on the growth conditions: the growth temperature, the amount of deposited material, and the growth rate interruption. A maximum dot density of 4 × 1010 cm–2 was achieved. The optical properties were studied after overgrowing of the QDs with a GaN cap layer. We observed very intense luminescence in the region between 2.4 and 2.8 eV and decay times of 1.8 ns under resonant excitation. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The effect of a Mg‐doped GaN cap layer on the optical properties of InGaN/AlGaN multiple quantum well structures
Authors: Graham D. M. , Dawson P. , Zhang Y. , Costa P. M. F. J. , Kappers M. J. , Humphreys C. J. , Thrush E. J.
Published: May 2006

We have studied the effect of depositing a Mg‐doped GaN cap layer on near‐ultraviolet emitting In0.05Ga0.95N/Al0.05Ga0.95N multiple quantum well structures, using photoluminescence spectroscopy and transmission electron microscopy. The room temperature (T = 300 K) photoluminescence spectra revealed a reduction in the integrated photoluminescence intensity of the capped structure, which is shown by time decay measurements to be due to greater competition from non‐radiative recombination processes. The structural analysis of the samples using electron microscopy has not shown any evidence of Mg‐induced defects. We suggest that the non‐radiative recombination path is related to the diffusion of Mg atoms into the quantum well region and the formation of Mg‐nitrogen vacancy complexes. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Advanced buffers for AlGaN/GaN HEMT and InGaN/GaN MQW on silicon substrates
Authors: Dikme Y. , Fieger M. , Eickelkamp M. , Giesen C. , Lutsenko E. V. , Yablonskii G. P. , Szymakowski A. , Jessen F. O. , Vescan A. , Kalisch H. , Heuken M. , Jansen R. H.
Published: May 2006

GaN growth was carried out on silicon (Si) substrates by metalorganic vapor phase epitaxy (MOVPE). A layer structure starting with HT (high‐temperature) AlN and containing AlGaN and GaN as interlayers was employed for the subsequent deposition of GaN buffer layers. At first, the influence of the in‐situ Al pre‐deposition at the process start with different durations was investigated. Each time, the pre‐deposition was followed by the same layer sequence and with thin AlGaN and GaN grown on top to form a high electron mobility transistor (HEMT). A significant enhancement could be observed in the properties of the investigated samples by reducing the pre‐deposition time from 8 s to 2 s. Based on these results, multiple quantum well structures (MQW) and HEMT were grown on these buffers. For the MQW, the well thickness was increased and a shift to higher wavelengths was observed. The HEMT structures have shown enhanced properties by optimizing the growth temperatures of the top AlGaN layer. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Radiative recombination mechanism in highly modulation doped GaN/AlGaN multiple quantum wells
Authors: Arnaudov B. , Paskov P. P. , Haratizadeh H. , Holtz P. O. , Monemar B. , Kamiyama S. , Iwaya M. , Amano H. , Akasaki I.
Published: May 2006

We have studied the low‐temperature optical emission spectra in a set of GaN/AlGaN multiple quantum wells with heavily Si‐doped barriers. A careful analysis of the evolution of the emission lineshape with doping density suggests that the dominant recombination mechanism involves transitions between free two‐dimensional (2D) electrons and non‐equilibrium holes localized near the valence band edge. We propose a lineshape model, which is found to be in a good agreement with experimental spectra if the penetration of the barrier hole localization potential into the wells, the Burstein‐Moss effect, and the band‐gap renormalization are taken into account. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical cavity formation on GaN using a conventional RIE system
Authors: Kalaitzakis F. G. , Konstantinidis G. , Tsagaraki K. , Androulidaki M. , Pelekanos N. T.
Published: May 2006

We report on the fabrication of mirror‐like facets on GaN‐based laser structures, using a conventional RIE system and photoresist AZ 5214 as the etch mask. The roughness of the etched sidewalls is below 100 nm and the slope is practically vertical. For enhanced material protection during plasma etching, we describe an alternative lithography procedure with a double photoresist layer. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical spectra of (1‐101) InGaN/GaN and GaN/AlGaN MQW structure grown on a 7 degree off axis (001) Si substrate
Authors: Kim Eun‐Hee , Hikosaka Toshiki , Narita Tetsuo , Honda Yoshio , Sawaki Nobuhiko
Published: May 2006

InGaN/GaN and GaN/AlGaN MQW waveguides were fabricated on a (1‐101) GaN facet grown on a 7‐degree off oriented (001) Si substrates by MOVPE. We achieved uniform layers with less dislocation density and superior flatness by virtue of the low growth rate on the facet. Using a nitrogen laser as the excitation source, the optical gain spectra as a waveguide was evaluated. In the InGaN/GaN MQW structure, we found that the optical gain was as high as +40 cm‐1 at near band edge emission peak. The GaN edge emission peak showed narrowing by high intensity excitation: the full width at half‐maximum 1.8nm at under 4.5 MW/cm2 at 77 K. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Molecular beam epitaxy for high‐efficiency nitride optoelectronics
Authors: Heffernan J. , Kauer M. , Windle J. , Hooper S. E. , Bousquet V. , Zellweger C. , Barnes J. M.
Published: May 2006

We review the significant progress made in the development of nitride laser diodes by molecular beam epitaxy (MBE). We report on our recent result of room temperature continuous‐wave operation of InGaN quantum well laser diodes grown by MBE. Ridge waveguide lasers fabricated on freestanding GaN substrates have a continuous‐wave threshold current of 125 mA, corresponding to a threshold current density of 5.7 kA cm–2. The lasers have a threshold voltage of 8.6 V and a lifetime of several minutes. We outline the further technical challenges associated with demonstrating lifetimes of several thousand hours and present an assessment of the potential of MBE as a growth method for commercial quality nitride optoelectronic devices. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High and low energy proton irradiation effects on AlGaN/GaN HFETs
Authors: Sonia G. , Richter E. , Lossy R. , Mai M. , Schmidt J. , Weyers M. , Tränkle G. , Denker A. , Opitz‐Coutureau J. , Pensl G. , Brauer I. , Strunk H. P.
Published: May 2006

AlGaN/GaN heterojunction field effect transistors (HFETs) have been irradiated with protons at 68 MeV and 2 MeV with fluences up to 1013 cm–2 in order to simulate operation in space. Hall effect measurements, dc characteristics and RF load pull measurements at 2 GHz do not reveal significant changes indicating the suitability of the transistors for reliable operation in space. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Identifying the most successful dose (MSD) in dose‐finding studies in cancer
Authors: Zohar Sarah , O'Quigley John
Published: May 2006

For a dose finding study in cancer, the most successful dose (MSD), among a group of available doses, is that dose at which the overall success rate is the highest. This rate is the product of the rate of seeing non‐toxicities together with the rate of tumor response. A successful dose finding trial in this context is one where we manage to identify the MSD in an efficient manner. In practice we may also need to consider algorithms for identifying the MSD which can incorporate certain restrictions, the most common restriction maintaining the estimated toxicity rate alone below some maximum rate. In this case the MSD may correspond to a different level than that for the unconstrained MSD and, in providing a final recommendation, it is important to underline that it is subject to the given constraint. We work with the approach described in O'Quigley et al. [Biometrics 2001; 57(4):1018–1029]. The focus of that work was dose finding in HIV where both information on toxicity and efficacy were almost immediately available. Recent cancer studies are beginning to fall under this same heading where, as before, toxicity can be quickly evaluated and, in addition, we can rely on biological markers or other measures of tumor response. Mindful of the particular context of cancer, our purpose here is to consider the methodology developed by O'Quigley et al. and its practical implementation. We also carry out a study on the doubly under‐parameterized model, developed by O'Quigley et al. but not actually studied in their paper. Copyright © 2006 John Wiley & Sons, Ltd.
The moderating role of development stage in free/open source software project performance
Authors: Stewart Katherine J. , Gosain Sanjay
Published: May 2006

The main thesis developed and tested in this article is that development stage plays an important moderating role in determining both objective and subjective performance outcomes in free/open source software (F/OSS) projects. This contention is supported by an empirical study of 67 F/OSS projects, with results indicating that subjective performance assessments are calibrated to different objective performance indicators across early and later development stages. The role of team climate variables (trust and shared ideology) in determining both objective and subjective performance also varies across stages. The findings have implications for improving software development processes through appropriate human resource management interventions over the course of F/OSS software projects. Copyright © 2006 John Wiley & Sons, Ltd.
Using component metadata to regression test component‐based software
Authors: Orso Alessandro , Do Hyunsook , Rothermel Gregg , Harrold Mary Jean , Rosenblum David S.
Published: May 2006

Increasingly, modern‐day software systems are being built by combining externally‐developed software components with application‐specific code. For such systems, existing program‐analysis‐based software engineering techniques may not directly apply, due to lack of information about components. To address this problem, the use of component metadata has been proposed. Component metadata are metadata and metamethods provided with components, that retrieve or calculate information about those components. In particular, two component‐metadata‐based approaches for regression test selection are described: one using code‐based component metadata and the other using specification‐based component metadata. The results of empirical studies that illustrate the potential of these techniques to provide savings in re‐testing effort are provided. Copyright © 2006 John Wiley & Sons, Ltd.
Integrating techniques and tools for testing automation
Authors: Polo Macario , Tendero Sergio , Piattini Mario
Published: May 2006

This article presents two tools to generate test cases, one for Java programs and one for .NET programs, as well as a structured testing process whereby such tools can be used in order to help in process automation. The main innovation in this work is the joint use of diverse techniques and technologies, which have been separately applied to test automation: reflection to extract the class structure; regular expressions to describe test templates and test cases; JUnit and NUnit as test case execution frameworks; mutation and MuJava as test case quality measurers; serialization to deal with the parameters of complex data types; and once more, reflection, to facilitate the test engineer in the task of writing the oracle. Finally, the article presents an experiment carried out to validate the work. Copyright © 2006 John Wiley & Sons, Ltd.
Further observations in a case of uridine diphosphate galactose‐4‐epimerase deficiency with a severe clinical presentation
Authors: Henderson M. J. , Holton J. B. , MacFaul R.
Published: May 2006

The red‐cell concentrations of galactose‐1‐phosphate and uridine diphosphate galactose have been studied in relation to dietary galactose in a case of uridine diphosphate galactose‐4‐epimerase deficiency (McK usick 23035). Uridine diphosphate galactose accumulates rapidly in response to very small amounts of galactose but the concentration of galactose‐1‐phosphate increases proportionately to galactose intake. The significance of the observation is discussed with respect to the pathogenesis and treatment of the disease.
The management of rhabdomyosarcoma in children and young adults
Authors: Hays Daniel M.
Published: May 2006

Survival rates among children with rhabdomyosarcoma have increased from approximately 20% to 70% during the past 15 years, and this improvement appears to be progressive. The major factor in this remarkable development has been the increasing effectiveness of multiple‐agent, long‐range chemotherapy regimens in (a) destroying micrometastasis, (b) controlling residual tumor at the sites of local excision, and (c) eliminating established metastatic tumor foci. Improved radiation therapy techniques and operative surgical procedures have been coordinated with this chemotherapeutic approach, largely in an adaptive fashion, resulting in multimodality therapy programs of increasing effectiveness. During the past decade, additional histologic variants of tumor have been identified, new techniques for accurately defining the extent of disease have been developed, and forms of vigorous supportive therapy have been employed for the first time. All of these have contributed to improvement in the results of therapy.
Malignant lymphomas in children
Authors: Exelby Philip R.
Published: May 2006

Malignant lymphomas are tumors of lymphoid tissue that make up almost 30% of cancers in childhood. The term “lymphoma” covers a variety of histologic types of tumor that have been placed in many different classifications. Based on biological behavior and current management, it is convenient to divide lymphomas in children into 2 broad categories: (a) Hodgkin’s disease, and (b) non‐Hodgkin’s lymphoma. Hodgkin’s disease in children resembles the disease in adults. It is a slowly progressive chronic disease, often lacking in systemic symptoms in early stages. Evaluation of Hodgkin’s disease involves careful determination of extent of disease by radiologic, scanning, biochemical, and surgical staging techniques. Non‐Hodgkin’s lymphoma, in contrast, is one of the most rapidly growing cancers in children. The disease differs greatly from adult non‐Hodgkin’s lymphoma both in behavior and management. The rapid clinical course and early spread to bone marrow and central nervous system resembles acute leukemia more than adult non‐Hodgkin’s lymphoma. The children are often extremely sick at the time of diagnosis and evaluation. More than a 24‐hour delay in treatment may increase the problems of subsequent management and jeopardize cure. The planned staging laparotomy carried out electively in Hodgkin’s disease has no place in the management of non‐Hodgkin’s lymphoma in children. Surgery in this tumor consists of biopsy of peripheral node for diagnosis and determination of peripheral nodal presentation, and exploratory laparotomy for resection of gross tumor in abdominal presentation. Whereas the pretreatment evaluation may take 1 week in Hodgkin’s disease, non‐Hodgkin’s lymphoma requires urgent induction of chemotherapy within 48 hours of diagnosis. This discussion of lymphoma in children involves separate considerations of Hodgkin’s disease and non‐Hodgkin’s lymphoma. The reader should think of these groups as 2 distinct diseases requiring quite different types of management.
Cimetidine in the management of synchronous crises of MEA I
Authors: Friesen Stanley R. , Hermreck Arlo S. , Brackett Charles E. , Schimke R. Neil
Published: May 2006

The clinical problems associated with the simultaneous and critical presentation of acute hyperparathyroidism and perforated jejunal ulceration in multiple endocrine adenopathy (MEA type I) require a multidisciplinary approach to management. In the patient described here, the use of cimetidine, a histamine‐2 receptor blocker, provided sufficient time after surgical closure of the ulcer to control the hypercalcemic crisis medically and surgically, until the persistent hypergastrinemia could be corrected by sequential excisions of the stomach and pancreaticoduodenal apudomas and hyperplasia. The serum gastrin levels, basal and stimulated (by secretin), provide necessary indications for surgical management of otherwise undetected islet cell pathology. The simultaneously associated pituitary hyperprolactinemia in this patient required both surgical and radiologic therapy.
Radiolabeled autologous leukocyte scanning in abscess detection
Authors: Ascher Nancy L. , Forstrom Leroy , Simmons Richard L.
Published: May 2006

Use of ultrasonography, computed tomography,67gallium scintiscanning, and111indium scintiscanning of labeled autologous leukocytes in the detection of intra‐abdominal infection is reviewed.111In scintiscanning in 405 patients demonstrated 152 sites of acute inflammation or septic foci in the abdomen in 138 patients; the calculated specificity was 92% and the overall diagnostic accuracy was approximately 90%. Success with111In scintiscanning has led us to use it routinely as a screening procedure 5 and 10 days postoperatively to detect intraperitoneal sepsis in high risk postoperative patients.
Collagenolysis: The other side of the equation
Authors: Peacock Erle E.
Published: May 2006

At least 18 mammalian collagenases have been identified. Acting at neutral pH and under physiological conditions these powerful enzymes cleave the collagen molecule and produce soluble fractions. Thus, tissue collagenase provides balance for collagen synthesis and completes the metabolic equation. Because tissue collagenase is produced only by living cells upon demand, there is no reservoir or pool of active enzyme. Inhibitors and accelerators of collagenolysis have been identified. Such agents have immediate therapeutic implications for conditions characterized by undesirable fibrous tissue.
Internal overhealing: The problem of intraperitoneal adhesions
Authors: Ellis Harold
Published: May 2006

Adhesions commonly follow laparotomies and are a frequent cause of intestinal obstruction in the Western World. They have been regarded as passive scar tissue which results from serosal damage, but both clinical and experimental studies confirm that they act as vascular grafts developing in response to the presence of ischemic tissue within the peritoneal cavity. Peritoneal defects, if left open and vascularised, heal rapidly by fibroblast differentiation into a smooth new serosa.
Selective or routine intraoperative cholangiography: A cost‐effectiveness analysis
Authors: Holmin Torsten , Jönsson Bengt , Lingren Björn , Olsson Sven‐Åke , Petersson Bengt G. , Sörbris Ralph , Bengmark Stig
Published: May 2006

In a retrospective analysis of 819 patients operated on for gallbladder disease, the costs and mortality rates were compared for 2 different strategies: (a) routine use of intraoperative cholangiography, or (b) selective use of intraoperative cholangiography on patients fulfilling at least 1 of 4 common clinical criteria. Selective use led to lower costs and lower mortality rates. The main reason for this outcome was that the benefits of detecting more stones in the bile duct by the routine use of cholangiography were counterbalanced by an increase in costs and risks because false‐positive operative cholangiograms led to a greater number of unnecessary choledochotomies.
Selective arterial embolization in traumatic hemobilia
Authors: Lykkegaard Nielsen Mogens , Mygind Thorkild
Published: May 2006

A patient with massive hemobilia secondary to blunt hepatic trauma and intrahepatic hematoma was successfully treated by transcatheter embolization of the right hepatic artery.
Anesthesia and monitoring for aortic aneurysm surgery
Authors: Ahmad Saleh Salwa
Published: May 2006

Cardiopulmonary bypass is employed in the treatment of aneurysms of the ascending aorta and transverse aortic arch. Anesthesia in these cases is similar to that used in the treatment of cardiac lesions requiring cardiopulmonary bypass. Most surgeons use some form of bypass or shunt for aneurysms in the distal arch, descending thoracic aorta, and the thoracoabdominal aortic segment. My surgical associate replaces these lesions with grafts without bypass or shunt, using simple cross‐clamping technique. This paper is concerned with anesthetic technique and general supportive measures that provide safety for this method of treatment.

Anesthesia and muscle relaxation is obtained by drugs that do not depress the myocardium. Surgical exposure and lung protection are facilitated by one lung ventilation, collapsing the left lung with a double lumen endobronchial tube. Blood pressure and cardiac hemodynamics are extensively monitored and controlled by administration of intravenous fluids and nitroprusside, as indicated. Serum electrolytes, blood gases, plasma osmolarity, acid‐base balance, and body temperature are frequently monitored and maintained in safe range. Blood coagulability is assessed and normal ranges achieved by appropriate therapy.
Prospective study of the effect of resection of the rectum on male sexual function
Authors: Fazio Victor W. , Fletcher John , Montague Drogo
Published: May 2006

A prospective study to evaluate sexual dysfunction following resection of the rectum was performed in 21 male patients. Following proctocolectomy for inflammatory bowel disease (9 patients), the incidence of sexual dysfunction was 11%, and it was always partial. Following abdominoperineal excision of the rectum for carcinoma (7 patients), the incidence of sexual dysfunction was 50%, and it was total in 16%. After anterior resection with low colorectal anastomosis (5 patients), the incidence of sexual dysfunction was 40%. The risk of dysfunction following operations on the rectum increased with the age of the patient and was minimal below the age of 50 years. In patients with inflammatory bowel disease, careful dissection close to the rectum should avoid damage to the pelvic nerves, and the incidence of sexual dysfunction should be low.
Total parenteral nutrition in the management of Crohn's disease
Authors: Descos L. , Vignal J.
Published: May 2006

A review of the recent literature is cited in support of the use of total parenteral nutrition (TPN) in Crohn's disease. The principal indications for this use are described and some of the disadvantages are discussed.
Total parenteral nutrition in Crohn's disease
Authors: Bos L. P. , Weterman Irene T.
Published: May 2006

A personal experience involving use of total parenteral nutrition in 115 patients with Crohn's disease is reported from a medical unit. Remission occurred without surgery in 24 patients. The regimen was considered to have failed in its objectives in 50 patients, and complications were recorded in 57.
The prevention and treatment of the persistent perineal sinus
Authors: Ferrari Bernard T. , DenBesten Lawrence
Published: May 2006

There is a high reported incidence of persistent perineal sinus after proctectomy for inflammatory bowel disease. The cause and prevention are discussed. In a consecutive series, persistent perineal sinuses occurred in 4 of 17 patients with Crohn's colitis, and in none of 20 patients with ulcerative or unclassified colitis (1 died soon after operation). The technique is described for patients with a sinus persisting for more than 6 months, using total excision, primary closure, and suction drainage. Six of 7 patients so treated healed primarily and the seventh healed within 2 weeks. In males, sexual dysfunction was often decreased.
A clinicopathologic study of choledochal cyst
Authors: Miyano Takeshi , Suruga Keijiro , Chen Soul‐Chin
Published: May 2006

Choledochal cyst is quite common in Japan. The etiology of this lesion is not clear, and there remain problems in its treatment as well.

Radiologic investigation of the distal common bile and pancreatic ducts was performed by operative cholangiography and endoscopic retrograde cholangiopancreatography. Anomalies at the junction of these ducts were found in all of the patients. Localized cystic dilatation of the extrahepatic bile ducts without intrahepatic bile duct dilatation was produced experimentally by ligation of the distal choledochus in infant rats. Concerning the etiology, we agree with Babbitt's hypothesis that weakness of the choledochal wall is produced by reflux of pancreatic juice via an anomalous choledochopancreatic junction. We think that the stenosis associated with this anomaly is the critical factor.

From our follow‐up study of 30 cases, we find excision of the cyst to be the most important part of treatment. Choledochal cysts presenting under 6 months of age had clinical symptoms and pathology similar to biliary atresia.
Prophylaxis of postoperative venous thrombosis in a controlled trial comparing dextran 70 and low‐dose heparin
Authors: Bergqvist David , Hallböök Torgil
Published: May 2006

A controlled, randomized trial comparing dextran 70 and low‐dose heparin with no treatment for prophylaxis of postoperative deep vein thrombosis is reported. A total of 168 patients who underwent general and urologic surgical operations participated in the trial. The125I‐fibrinogen test was used for diagnosis. The frequency of deep venous thrombosis was 27% in controls, 29% in patients who also received dextran 70, and 13% in patients treated with low‐dose heparin. Only heparin therapy reduced the incidence of thrombosis. Epidural analgesia did not reduce the frequency of thrombosis. In patients with malignant diseases, the thrombotic process always extended proximally, at least to the knee. The highest frequency of thrombosis was seen after urologic surgery. Complications did not differ between the groups.
Thromboendarterectomy combined with femoropopliteal bypass
Authors: Stavorovsky M. , Iellin A.
Published: May 2006

Most complications that appear within 5–6 weeks after femoropopliteal bypass (FPB) are associated with the surgical procedure in the groin. Destruction of lymphatic structures in the presence of an open foot infection and crushing of the intima by clamping the common and deep femoral arteries are significant predisposing factors in producing early infection or occlusion of the graft. To avoid these predisposing factors, a combined procedure of a short thromboendarterectomy of the proximal superficial femoral artery and an autogenous or prosthetic bypass graft was used, without application of clamps to the common and deep femoral arteris. In a series of 45 patients, this combined procedure was used and a significant reduction of complications was achieved. Indications, technique, and advantages of this combined method are discussed.
Duodenal ulcer disease in children
Authors: Maudar K. K. , Dutta J. , Mitra S.
Published: May 2006

Eleven cases of chronic duodenal ulcer in children were subjected to surgical treatment in a period of 7 years. The diagnosis was based on typical peptic ulcer symptoms, hyperchlorhydria, and barium meal x‐ray studies delineating a duodenal bulb deformity with an ulcer crater in 8 patients. Three cases of duodenal ulcer perforation in infants were diagnosed at laparotomy for peritonitis with pneumoperitoneum. All the patients hailed from the region of Assam, India, where peptic ulcer is prevalent. A positive family history of peptic ulcer in 5 patients, blood group O in 7 patients, and the regional diet were considered to be predisposing factors. Medical treatment consisting of a bland diet, sedatives, antispasmodics, and a brief hospital stay failed to provide permanent relief of symptoms. Truncal vagotomy with a drainage procedure was done in 8 patients with no deaths. However, simple closure of the perforation in the 3 infants resulted in fatalities due to fulminant septicemia.

The patients were followed up for 1–8 years. Six patients had permanent relief of symptoms. Two patients occasionally complained of epigastric fullness and eructation. They showed normal growth, gain in weight and hemoglobin levels, and had no recurrence. We believe that operative treatment is preferable to medical management of chronic duodenal ulcer in children.
Ultrasonic and computed tomographic imaging of the abdominal aorta
Authors: Hattery Robert R. , Williamson Byrn , Wallace Robert B.
Published: May 2006

Although ultrasonic and computed tomographic technology is continuing to evolve, these already sophisticated imaging tests have become the primary methods of evaluating the patients with aortic aneurysms. Both modalities are accurate and noninvasive. The major value of these techniques to the surgeon is in assessing those patients in whom the diagnosis is in doubt and in following patients in whom it has been elected to observe a small stable aneurysm. Changes in an aneurysm can be detected on serial examinations which might indicate the need for surgery in spite of adverse patient risk factors, and these techniques may provide a means of detecting false aneurysms in patients who are difficult to assess accurately by physical examination. Ultrasound and computed tomography are very helpful techniques in the diagnosis and assessment of aortic aneurysms. These diagnostic modalities are not required in every patient and should be used discriminately and when indicated.
Progress in treatment of aneurysms of the aortic arch
Authors: Arisan Ergin M. , Griepp Randall B.
Published: May 2006

A review of past and current operative procedures for treatment of aneurysms of the aortic arch is presented in conjunction with a series of 14 patients in whom the aortic arch and variable portions of the ascending and descending aorta were replaced utilizing a combination of surface cooling and cardiopulmonary bypass to produce profound total body hypothermia. Arch replacement was carried out during a single period of circulatory arrest. Cardiopulmonary bypass was then utilized to warm the patient and resuscitate the heart. The average cerebral ischemia time was 42 minutes at an average core temperature of 14°C. The average myocardial ischemia time was 68 minutes, and the average duration of cardiopulmonary bypass was 122 minutes. There were 4 deaths in this series. Of the 10 patients undergoing elective operation only 1 died. The remaining patients are alive and well 4 months to 6 years following surgery. This experience indicates that by utilizing total body hypothermia and circulatory arrest, aortic arch replacement can be carried out with superior results. This technique is our method of choice and should find increasing application.
Surgery of the trachea
Authors: Perelman Mikhail , Koroleva Nataliia
Published: May 2006

Experience with surgical treatment of 164 patients with various diseases of the trachea at the All‐Union Institute of Clinical and Experimental Surgery in Moscow since 1963 is summarized. The main diagnostic methods used in tracheal diseases were tracheography and tracheoscopy with biopsy. Operations were performed for malformation, trauma, exflammatory disease, benign and malignant tumors, nontumoral stenoses, and esophagotracheal fistula. A bypass respiration system was used in the majority of patients after tracheal transection. Hyperbaric oxygenation added to the bypass respiration system made it possible to interrupt lung ventilation during operations on the trachea for long periods.

The best operative approach to the thoracic trachea was a partial sternotomy and posterior thoracotomy. The standard approach to the tracheal bifurcation was a posterior right thoracotomy.

The various operations performed on the trachea included sleeve resection with end‐to‐end anastomosis, resection of the tracheal bifurcation, window resection, tumoral incision in the opened trachea, plastic repair of esophagotracheal fistula, and strengthening of the membranous trachea. Six variations of resection of the tracheal bifurcation were performed. In cases of sleeve resection, operative risk was minimized by suturing the left main bronchial stump closed, leaving the left lung in a state of atelectasis.

Of the 164 patients who underwent operation, 138 were discharged from the hospital and 26 (16%) died in the postoperative period. Bleeding from the brachiocephalic artery, pneumonia, thromboembolism of the pulmonary artery, and anastomotic leak were the causes of death. Operations on the trachea and its bifurcation require special anesthesia and surgical expertise in tracheobronchial procedures.
The effect of antiaggregating drugs on the patency of grafts in the arterial system
Authors: Pirk Jan , Ružbarský Vladimír , König Jiří , Krajíček Milan , Pavel Petr , Firt Pavel
Published: May 2006

In experiments in dogs we studied the effect of anti‐aggregating agents on the patency of prosthetic vascular grafts (4 mm in diameter) and vein grafts, both placed in areas with a rate of flow ranging between 50–60 ml/min. All 6 prosthetic grafts became occluded in the nonmedicated controls, 1 of 5 prosthetic grafts remained patent for a prolonged period of time in dogs receiving 250 mg acetylsalicylic acid 3 times a day, while 5 of 6 prosthetic grafts remained patent in animals receiving an antiaggregating mixture. Follow‐up studies showed that antiaggregating medication had no effect on the patency of vein grafts, but it prevented the formation of mural thrombi and subendothelial proliferation.
Breast cancer in the male: A report of 138 cases
Authors: Ramantanis G. , Besbeas S. , Garas J. G.
Published: May 2006

This is a report of 138 male patients with cancer of the breast who were treated at the Hellenic Anticancer Institute from 1937 to 1974. The overall 5‐year survival rate for 120 patients followed up was 32.5%. Analysis of the 5‐year survival rate in relation to the mode of treatment showed that for radical mastectomy it was 42.9%, for simple mastectomy 40.7%, and for lumpectomy 35%. There were no 5‐year survivors among patients treated with a combination of radiotherapy, chemotherapy, and hormonal manipulation. The 5‐year survival rate for stage I cancer was 54.6%, for stage II the rate was 48.7%, and for stage III it was 18.5%. There were no 5‐year survivors with stage IV cancer. The 5‐year survival rate for patients who underwent radical mastectomy with positive axillary lymph nodes was 30.8%, while for those in whom the axillary lymph nodes were negative it was 56.5%. The overall 10‐year survival rate was 14.8%.
Long‐term results of subtotal gastrectomy for duodenal ulcer
Authors: Dinbar A. , Avigad I. , Shafir R. , Tulcinsky D. B.
Published: May 2006

Long‐term clinical and metabolic results of subtotal gastrectomy for duodenal ulcer in 133 patients are reported. The operative procedure consisted of a 4/5 gastric resection with a retrocolic no‐loop Hoffmeister anastomosis. After detailed clinical and metabolic assessment, 84% of the patients were graded Visick grades I and II. Postgastrectomy symptoms were few, only mild or moderate in intensity, and were not disabling in any of the cases. No diarrhea or vomiting was noted. Weight loss was observed in 16% of the patients, 14% losing less than 5 kg. Diarrhea or malabsorption was not encountered in the entire series. The incidence of anemia was 5.5%. None of the hemoglobin levels were below 10.5 g/dl. All cases of anemia were microcytic, hypochromic, iron deficient. There were no hematological or clinical signs suggestive of macrocytic anemia in the entire series. Plasma protein, calcium, and phosphorus levels were within normal limits. All patients were free of clinical complaints and history suggestive of bone disease. It is believed that the low morbidity and the few and mild metabolic sequelae are due to the type of anastomosis used.
Mesocaval interposition shunt for portal hypertension: Results in 31 patients
Authors: Fourtanier Gilles , Lacroix André , Martinel Christian , Escat Jean
Published: May 2006

Mesocaval interposition shunt (MCS) with a dacron graft was performed for bleeding esophageal varices in 31 cirrhotic patients. Operative mortality rate was 29% overall, 40% for emergency MCS performed in 20 patients, and 9% for elective MCS performed in 11 patients. Bleeding was controlled in 75% of patients who underwent emergency MCS. Shunt patency rate was 90%. Long‐term follow‐up for an average of 26±13 months was possible in 21 patients. None of the survivors developed recurrent bleeding. Encephalopathy requiring hospitalization occurred in 28.5% of survivors.