bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laparoscopic repair of ventral incisional hernia
Authors: Kua Keith B. , Coleman Mark , Martin Ian , O’Rourke Nicholas 
Published: March 2003

Background: Laparoscopic repair of ventral incisional hernias was first reported in 1993. Since then, there have been sporadic case reports and small series published about this procedure, but it has not been widely adopted. Newer types of composite prosthetic mesh may reduce the potential problem of bowel adhesion. Methods: Thirty cases of laparoscopic ventral incisional hernia repairs (carried out by two surgeons or their senior registrars) have been retrospectively reviewed and reported in this article. The data were obtained from patient records and subsequent phone surveys. Results: Thirty patients between 29 and 82 years (mean: 58 years) underwent this procedure. There were 14 men and 16 women. The average weight of the patients was 81 kg. The hernias were up to 6 or 7 cm in diameter. Mesh was used in 28 cases (polypropylene in 25 cases, expanded polytetrafluoroethylene in two cases and composite mesh in one case). Most meshes were laid intraperitoneally and fixed into position with laparoscopic spiral tacks. Twenty‐nine cases were completed laparoscopically. One operation (3.3%) was converted to an open procedure because of severe bowel adherence to the hernia sac. The mean operating time was 52 min for laparoscopic ventral incisional hernia repairs only. All but two patients tolerated an oral diet within 24 h. The postoperative hospital stay ranged from 0 to 11 days, with 17 patients (57%) staying overnight and eight patients (27%) staying another day. Over 80% of the patients returned to house duties within a week. There was no mortality, and minor complications occurred in four patients (14%). One patient had a small bowel obstruction treated successfully by repeat laparoscopy with division of fibrinous adhesions to polypropylene mesh on day four. Follow up ranged from 1 to 69 months (mean: 12 months). One patient did not attend follow‐up appointments. There were three cases of hernia recurrence (10%). Conclusion: The results suggest that laparoscopic repair of ventral incisional hernias is a safe, effective and technically feasible operation for small‐ to medium‐sized hernias allowing shorter hospital stay, early recovery and resumption of normal activities. However, recurrence rates are comparable to open mesh hernioplasty especially for larger hernias.
Extent of mesorectal invasion is a prognostic indicator in T3 rectal carcinoma
Authors: Steel Malcolm C. A. , Woods Rodney , Mackay Jack M. , Chen Frank 
Published: March 2003

Background:  The aim of this study was to determine if local recurrence (LR) rates in patients with minimally invasive and advanced T3 rectal cancer are different. This may influence the use of adjuvant therapy.Methods:  Consecutive patients with T3 rectal cancer undergoing curative surgery were classified into minimally invasive or advanced groups. Minimally invasive T3 was defined as a tumour that had invaded beyond the muscularis propria on microscopic examination only, whereas advanced T3 tumours had invasion beyond the muscularis propria that was obvious on macroscopic examination and confirmed histologically. Local recurrence rates of the two groups were compared by construction of Kaplan−Meier curves. The log‐rank test was used to determine equivalence, and Cox regression to estimate the hazard ratio. The Grambsch− Therneau test and graphical comparison of predicted and observed Kaplan−Meier curves was used to test the proportional hazards assumption.Results:  There were 222 patients in total, 74 in the minimally invasive group and 148 in the advanced. The overall LR rate was 11.2%. The LR rates in the minimally invasive and advanced groups were 5.4% and 14.2%, respectively. The log‐rank test gives a P value of 0.042 for equivalence, with the minimally invasive patients doing significantly better. The hazard ratio estimated by Cox regression was 0.35 (early relative to advanced), 95% confidence intervals (0.12, 1.0). There was no evidence of confounding by age at surgery, pathology type, gender or postoperative adjuvant therapy.Conclusions:  The extent of invasion into the mesorectum appears to be an independent prognostic variable. If oncologically sound surgical techniques are employed, the LR rate of patients with minimal invasion is low. Adjuvant therapy may not confer additional benefit in this group.
Baseline comparisons in surgical trials
Authors: Hall John C. , Hall Jane L. 
Published: March 2003

Introduction:  Baseline measurements are an essential component of clinical trials. They should establish that the groups involved are clinically equivalent so that any observed differences can be attributed to the intervention under evaluation. The objective of this study was to review the use of baseline comparisons in surgical trials.Methods:  A standardized format was used to evaluate 206 surgical trials published within 10 prestigious journals between January 1997 and December 1999.Results:  One hundred and fifty‐one (73%) of the trials used the first table in the article to record baseline data. More than one‐quarter of the trials declared less than five items and one‐third of the trials inappropriately used ‘P‐values’ as a measure of baseline equivalence. Only nine of the 54 multicentre studies (17%) mentioned the individual centres as possible confounding factors.Discussion:  Greater attention needs to be paid to baseline comparisons in surgical trials. One way of developing this type of critical ability is to use a checklist while reading a surgical trial of interest. Good resources include the CONSORT Statement by a group of prominent international biostaticians and the CLEAR (Critical Literature Evaluation and Research) Courses run by the Royal Australasian College of Surgeons.
Ankle fractures: Functional and lifestyle outcomes at 2 years
Authors: Lash Nicholas , Horne Geoffrey , Fielden Jann , Devane Peter 
Published: March 2003

Background:  Ankle fractures form a high proportion of the total number of fractures treated in New Zealand. International studies show that there are mixed functional outcomes with differing fracture types and subsequently differing lifestyle outcomes.Methods:  Fracture clinic records and orthopaedic admissions books for Wellington Public Hospital, Capital Coast Health, ­Wellington, were retrospectively reviewed to gain a population of patients who sustained ankle fractures for the period January−­December 1998. These patients were asked to fill in postal questionnaires detailing their current ankle function and lifestyle, two years after fracturing their ankle. The patients’ radiographs were reviewed to classify the types of ankle fractures sustained.Results:  Of 141 patients that sustained ankle fractures, 74 were followed up 2 years after their ankle fracture. All fracture types averaged Olerud‐Molander ankle scores of 71.1. Weber A fractures averaged ankle function scores of 90, Weber B fractures 80, and Weber C fractures 78. Four patients (5%) achieved ‘poor’ results, 12 (16%) patients achieved a ‘fair’ result, 30 (41%) patients gained a ‘good’ result, 27 (36%) patients attained ‘excellent’ results. Lifestyle outcomes were reflected in the patient’s ankle function outcomes (P < 0.05).Conclusion:  Patients who sustain ankle fractures can be expected to be still experiencing functional difficulties two years post‐treatment.
Paediatric elective surgical conditions as seen at a referral hospital in Kumasi, Ghana
Authors: Abantanga Francis A. , Amaning Eric P. 
Published: March 2003

Background:  Data on paediatric surgical conditions in sub‐Saharan countries, including Ghana, are scanty and sketchy. Using hospital‐based data, it is possible to assess the epidemiology of diseases among children, and the morbidity and mortality rates.Methods:  Between January 1997 and December 2000, records of 1200 children treated consecutively with elective surgery at Komfo Anokye Teaching Hospital in Kumasi, Ghana, were analysed for name, age, sex, postoperative diagnosis, procedure carried out and outcome of treatmentResults:  The ages of the children ranged from 0 to 14 years, with a mean age of 3.5 years (95% confidence interval: 3.3−3.7) with a boy/girl ratio of 3.1:1. Congenital anomalies were the most common problem (83%), followed by tumours (4%), cysts (3%), uncircumcised penis (2%), and lymphadenopathy of varying aetiologies (2%). The most common congenital anomaly was inguinal hernia, and the rarest, biliary atresia. Eighty‐two percent of the children in this series were treated as day‐care cases. Overall mortality in the series was 0.8%.Conclusions:  The data reviewed here demonstrate that there is a wide range of surgical conditions among children in the developing world. This poses a significant health‐care problem and calls for improved management of such paediatric surgical problems to prevent high morbidity and mortality rates in African children.
A NOTE ON MODELLING SHORT FATIGUE CRACK BEHAVIOUR
Authors: Angelova D , Akid R 
Published: March 2003

Based upon experimental short fatigue crack growth data and adopting the Brown–Hobson model, new crack growth equations have been derived in an attempt to describe more precisely short fatigue crack growth behaviour that separates the physically small crack regime from the long crack regime. An empirical model for physically small crack growth was developed by employing elastic–plastic fracture mechanics parameters.By considering the proposed approach to short fatigue crack modelling, a new second ‘microstructural’ threshold condition has been established using only short fatigue crack growth data. In the case of fatigue in an aggressive environment it is suggested that three transition (threshold) conditions can be identified representing: (i) a stress‐assisted pitting/pit‐to‐crack transition; (ii) a microstructurally short shear crack/physically small tensile crack transition; and (iii) a physically small crack/long crack transition.A comparison of this approach with that of existing models has been made, and predictions of total fatigue lifetime using the model have been presented. A reasonable agreement has been observed between predicted and experimental crack growth rates.
ANALYSIS OF CAST STEEL FRACTURE MECHANISMS FOR DIFFERENT STATES OF STRESS
Authors: Biel‐ M 
Published: March 2003

The process of fracture in a low‐carbon cast steel was studied for different states of stress. As a result of heat treatment, two different microstructures have been obtained: ferritic‐pearlitic and bainitic. The triaxial states of stress were realised by tensile tests on specimens with various notch configurations and on smooth specimens subjected to different hydrostatic pressures.During tensile tests carried out under triaxial stress states, the following quantities at fracture were determined: the effective strain, effective stress, stress state components, mean stress and stress triaxiality factor. Fractography of the specimens was carried out to observe the fracture mechanisms and relate them to the state of stress. The fracture mechanism depended on the state of stress and microstructure. With a decreasing stress triaxiality factor, the failure mechanism changed from ductile to shear. The fracture mechanism changed across the diameter of the sample and also depended on the microstructure. The small, smooth samples fractured at a higher stress than the larger samples. Ductile fracture in the ferritic‐pearlitic microstructure was controlled by cracking of the matrix–precipitate boundary. Samples with the bainitic microstructure fractured by shear, and fracture depended mainly on the effective stress, although void growth (which is controlled by stress triaxiality) reduced the critical effective stress at positive values of mean stress.
An approach to size effect in fatigue of metals using fractal theories
Authors: CARPINTERI ANDREA , SPAGNOLI A. , VANTADORI S. 
Published: March 2003

ABSTRACT As was experimentally observed by several authors, the fatigue strength of metallic materials decreases with increasing the specimen size. Such a decrease can be remarkable for very large structures like, for example, big cargo ships (some hundred meters long) transporting oil or other goods. Size effect in fatigue is herein explained by considering the fractal nature of the reacting cross sections of structures, that is, the renormalized fatigue strength is represented by a force amplitude acting on a surface with a fractal dimension lower than 2, where such a dimensional decrement depends on a self‐similar weakening of the material ligament, owing to the presence of cracks, defects, voids and so forth (microscopic level). However, this decrement tends to progressively disappear with increasing the structure size (macroscopic level), i.e. the effect of the material microstructure on the macroscopic fatigue behaviour gradually vanishes for structures large enough with respect to a characteristic microstructural size, this phenomenon being defined as multifractality. A multifractal scaling law for fatigue limit of metals is proposed, and some experimental results are examined in order to show how to apply the theoretical approach presented.
Microstructures of modified RR2072 single crystal superalloys and their effects on LCF response at 950 8°C
Authors: CHEN Q. Z. , JONES N. , KNOWLES D. M. 
Published: March 2003

ABSTRACTEffects of microstructural modifications, that are a consequence of adding minor grain boundary strengthening elements (C, Hf), on the fatigue response of an experimental single crystal superalloy have been studied. Investigations show that in the modified alloys, as a consequence of the casting process, the population of pores is reduced, but the average pore size increases and larger pores occur close to the fatigue sample surface. Such porosity changes in the modified alloys are an important contributor to their low cycle fatigue (LCF) properties. At the high stress range of LCF tests undertaken, the growth of cracks initiates from pores and their location in the modified alloys are responsible for decreased fatigue lives. At lower stress ranges, crack initiation consumes a considerable proportion of fatigue life. Since crack initiation involves strain localisation at or near the specimen surface where there is interaction with the environment, the population of pores near the specimen surface and the increased length of the tests plays a significant role in governing fatigue lives. The modified alloys benefit from their lower density of pores in the vicinity of the free surface, and tend to have comparable fatigue lives to that of the base alloy at the lower stress level.
Correlation between cyclic deformation behaviour and microstructure in a duplex steel between 300 and 773 K
Authors: ALVAREZ‐ARMAS I. , ARMAS A. F. , HEREÑÚ S. , DEGALLAIX S. , DEGALLAIX G. 
Published: March 2003

ABSTRACTCyclic tests performed in the temperature range 300–773 K on duplex stainless steel DIN 1.4460 show that the cyclic stress–strain behaviour of this steel is strongly temperature dependent. At 300 and 473 K an almost constant peak tensile stress stage, is followed by a slight softening that continues up to failure in the case of 300 K, but by a secondary hardening at 473 K. Pronounced initial cyclic hardening followed by secondary hardening was the main feature of the temperature range between 573 and 723 K. At 773 K, after a weak hardening stage, a strong softening continues up to failure. The mechanical behaviour and the evolution of the microstructure were analysed, and the internal and the effective stresses were studied. It was found that the internal stress is responsible for the strong hardening that occurs in the intermediate temperature range and for the softening at 773 K.
Estimations of creep fracture mechanics parameters for through‐thickness cracked cylinders and finite element validation
Authors: KIM Y.‐J. , HUH N.‐S. , KIM Y.‐J. 
Published: March 2003

ABSTRACTThis paper compares engineering estimation schemes of C* and creep crack opening displacement (COD) for cylinders with circumferential and axial through‐thickness cracks at elevated temperatures with detailed 3D elastic‐creep finite element results. Engineering estimation schemes include the GE/EPRI method; the reference stress (RS) method where the reference stress is defined based on the plastic limit load; and the enhanced reference stress (ERS) method where the reference stress is defined based on the optimised reference load, recently proposed by the authors. Systematic investigations are made not only on the effect of creep‐deformation behaviour on C* and creep COD, but also on effects of the crack location, the cylinder geometry, the crack length and the loading mode. Comparison of the finite element (FE) results with engineering estimations provides that for idealised power law creep, estimated C* and COD rate results from the GE/EPRI method agree best with FE results, suggesting that published plastic influence functions for plastic J and COD for through‐thickness cracked cylinders are reliable. For general creep‐deformation laws where either primary or tertiary creep is important and thus the GE/EPRI method is hard to apply, on the other hand, the ERS method provides more accurate and robust estimations for C* and COD rate than the reference stress method. As these two methods differ only in the definition of the reference stress, the ERS method maintains benefits of the reference stress method in terms of simplicity, but improves accuracy of the estimated J, C* and COD results.
Enhancing desulphurization by engineering a flavin reductase‐encoding gene cassette in recombinant biocatalysts
Authors: Galán Beatriz , Díaz Eduardo , García José L. 
Published: March 2003

Biological desulphurization of petroleum feedstocks and products may offer an attractive alternative to reduce sulphur oxide emissions that cause serious environmental pollution. Dibenzothiophene (DBT) desulphurization via the Dsz pathway of Rhodococcus erythropolis IGTS8 is an energetically expensive process that consumes reducing equivalents. We have shown in this work that the HpaC oxidoreductase from Escherichia coli W is able to supply the required FMNH2 to the Dsz monooxygenases. The cloning and expression of the hpaC gene in Pseudomonas strains bearing the dszABC gene cluster significantly enhanced DBT desulphurization efficacy of the recombinant biocatalysts in a resting‐cell process, thus indicating that overexpression of a heterologous flavin reductase in the host cell is critical for a high rate of sulphur removal in vivo. The hpaC and dszABC genes have been engineered as a single transcription unit under control of broad‐host‐range regulatory signals in a mobilizable DNA cassette that can be used to confer a DBT desulphurization phenotype to a wide variety of bacteria regardless of the expression of putative housekeeping flavin reductases within the host cells. This cassette will be very useful in exploring the biotechnological potential of novel biocatalysts for developing an efficient desulphurization process.
Anaerobic degradation of aromatic compounds coupled to Fe(III) reduction by Ferroglobus placidus
Authors: Tor Jason M. , Lovley Derek R. 
Published: March 2003

Aromatic compounds are an important component of the organic matter in some of the anaerobic environments that hyperthermophilic microorganisms inhabit, but the potential for hyperthermophilic microorganisms to metabolize aromatic compounds has not been described previously. In this study, aromatic metabolism was investigated in the hyperthermophile Ferroglobus placidus. F. placidus grew at 85°C in anaerobic medium with a variety of aromatic compounds as the sole electron donor and poorly crystalline Fe(III) oxide as the electron acceptor. Growth coincided with Fe(III) reduction. Aromatic compounds supporting growth included benzoate, phenol, 4‐hydroxybenzoate, benzaldehyde, p‐hydroxybenzaldehyde and t‐cinnamic acid (3‐phenyl‐2‐propenoic acid). These aromatic compounds did not support growth when nitrate was provided as the electron acceptor, even though nitrate supports the growth of this organism with Fe(II) or H2 as the electron donor. The stoichiometry of benzoate and phenol uptake and Fe(III) reduction indicated that F. placidus completely oxidized these aromatic compounds to carbon dioxide, with Fe(III) serving as the sole electron acceptor. This is the first example of an Archaea that can anaerobically oxidize an aromatic compound. These results also demonstrate for the first time that hyperthermophilic microorganisms can anaerobically oxidize aromatic compounds and suggest that hyperthermophiles may metabolize aromatic compounds in hot environments such as the deep hot subsurface and in marine and terrestrial hydrothermal zones in which Fe(III) is available as an electron acceptor.
Effects of two different application methods of Burkholderia ambifaria MCI 7 on plant growth and rhizospheric bacterial diversity
Authors: Ciccillo Fabio , Fiore Alessia , Bevivino Annamaria , Dalmastri Claudia , Tabacchioni Silvia , Chiarini Luigi 
Published: March 2003

SummaryIn order to acquire a better understanding of the effects of the different delivery modes of bacterial inoculants on plant growth and on the community structure of rhizosphere bacterial populations, Burkholderia ambifaria MCI 7 (formerly B. cepacia MCI 7) was inoculated into the rhizosphere of maize plants by either seed adhesion or incorporation into soil. Plant growth was evaluated at different inoculum concentrations. The community structure of rhizosphere bacterial populations was evaluated by analysing the restriction patterns of the DNA coding for 16S rRNA amplified by polymerase chain reaction (PCR) (ARDRA) of 745 bacterial isolates. A number of diversity indices (richness, Shannon diversity, evenness and mean genetic distance) were calculated for each bacterial population isolated from control and treated plants according to the concept of the r/K strategy. Moreover, the analysis of molecular variance (AMOVA) method was applied to estimate the genetic differences among the various bacterial populations. Our results showed that the method of application can be an essential element in determining the effects of the inoculant on plant growth. In fact, when applied as a maize seed treatment, B. ambifaria MCI 7 promoted plant growth significantly; on the contrary, when incorporated into soil, the same strain reduced plant growth markedly. As far as the bacterial community structure is concerned, B. ambifaria MCI 7 affected the indigenous microflora of treated plants according to the application method: seed treatment brought about an abrupt decrease in bacterial diversity, whereas incorporation into soil increased bacterial diversity. Moreover, changes in bacterial diversity were limited to r‐strategist bacteria. In conclusion, B. ambifaria MCI 7 can act as both a plant growth‐promoting rhizobacterium and a deleterious rhizobacterium depending on the inoculation method.